Section 3 Social Aspects

**157**

**Chapter 10**

Australians

non-indigenous Australians.

**1. Introduction**

*Alison Husain*

**Abstract**

Amnesia among Indigenous

Looking at the incidence of amnesia in Australian indigenous people who have experienced a legacy of intergenerational trauma and psycho-social traumas in childhood such as psychological, sexual and physical abuse, domestic violence, substance abuse, out-of-home care, and over-policing, this chapter will consider the impact of trauma-based amnesia from the perspective of social neuroscience in relation to the frequency of incidence derived from data on reported mood and neurotic group disorders to draw insights into the epidemiology of psychogenic amnesia among indigenous Australians. This chapter will also consider cultural implications as health is not just a physiological or mental status of an individual but encompasses social, emotional, and cultural connectedness which amnesia disrupts. This research seeks to create better understanding as to the causal attributes of more prevalent levels of suffering among indigenous Australians as compared to

**Keywords:** amnesia, psycho-social trauma, intergenerational trauma, indigenous Australians, mental health, epidemiology, dissociative and psychogenic amnesia

While much research has been undertaken on the neural mechanisms and effect of trauma-induced amnesia, it is suggested that much less attention has been applied to the more covert and pervasive types of trauma and long-term effects of psychogenic amnesia among indigenous Australians. This chapter is essentially a study in the application of social neuroscience in the psycho-social trauma frequently associated with childhood. The objective of this social neuroscience research is to understand the epidemiology of amnesia and related neurophysiological systems that underpin the traumatic social background of indigenous

This article analyses themes underlying the causes of childhood trauma, considers the impact leading to amnesia, available diagnosis and mitigation. The material was informed by a review of epidemiological literature on psycho-social trauma present in indigenous Australians with consideration given to international literature to determine the elements of collective and mass trauma studies which correlate to indigenous communities in Australia. Psychogenic amnesia as a specific mental disorder has not been recorded in the data history of indigenous and non-indigenous hospitalizations. Consideration has therefore been given to the group of mood and neurotic disorders within which psychogenic amnesia lies in particular arising from stress levels. This article will contemplate memory

Australians, and is intended to further understanding.

#### **Chapter 10**

## Amnesia among Indigenous Australians

*Alison Husain*

#### **Abstract**

Looking at the incidence of amnesia in Australian indigenous people who have experienced a legacy of intergenerational trauma and psycho-social traumas in childhood such as psychological, sexual and physical abuse, domestic violence, substance abuse, out-of-home care, and over-policing, this chapter will consider the impact of trauma-based amnesia from the perspective of social neuroscience in relation to the frequency of incidence derived from data on reported mood and neurotic group disorders to draw insights into the epidemiology of psychogenic amnesia among indigenous Australians. This chapter will also consider cultural implications as health is not just a physiological or mental status of an individual but encompasses social, emotional, and cultural connectedness which amnesia disrupts. This research seeks to create better understanding as to the causal attributes of more prevalent levels of suffering among indigenous Australians as compared to non-indigenous Australians.

**Keywords:** amnesia, psycho-social trauma, intergenerational trauma, indigenous Australians, mental health, epidemiology, dissociative and psychogenic amnesia

#### **1. Introduction**

While much research has been undertaken on the neural mechanisms and effect of trauma-induced amnesia, it is suggested that much less attention has been applied to the more covert and pervasive types of trauma and long-term effects of psychogenic amnesia among indigenous Australians. This chapter is essentially a study in the application of social neuroscience in the psycho-social trauma frequently associated with childhood. The objective of this social neuroscience research is to understand the epidemiology of amnesia and related neurophysiological systems that underpin the traumatic social background of indigenous Australians, and is intended to further understanding.

This article analyses themes underlying the causes of childhood trauma, considers the impact leading to amnesia, available diagnosis and mitigation. The material was informed by a review of epidemiological literature on psycho-social trauma present in indigenous Australians with consideration given to international literature to determine the elements of collective and mass trauma studies which correlate to indigenous communities in Australia. Psychogenic amnesia as a specific mental disorder has not been recorded in the data history of indigenous and non-indigenous hospitalizations. Consideration has therefore been given to the group of mood and neurotic disorders within which psychogenic amnesia lies in particular arising from stress levels. This article will contemplate memory

disorders by considering memory disturbances, relationships to functionality and frequency, before turning to aspects of therapeutic interventions and culturally safe approaches.

The use of social neuroscience in exploring the incidence of amnesia caused by emotional and psychological trauma among indigenous Australians will provide broader consideration of the causal attributes of more prevalent levels of suffering among indigenous Australians as compared to non-indigenous Australians [1]. Social neuroscience perspectives on childhood trauma unite the concept that the brain responds to stress and abuse, as social behaviors stem from brain development [2]. Consideration may then be given to development of best therapeutic practices to promote healing and recovery from the damage caused to brain development by adverse experiences.

#### **1.1 Background**

It cannot be emphasized enough that the colonialist practices of dispossession, child removal, suppression of indigenous social practices, stolen heritages and oppressive government policies, resulted in long-term intergenerational trauma that is still experienced today [3]. Ongoing social inequalities are particularly apparent across health outcomes [4, 5].

Current statistics indicate there are approximately 800,000 indigenous Australians, equating to 2.8% of the Australian population [6] (**Figure 1**).

The health and welfare outcomes are significantly disproportionate as indigenous Australians experience disease at a far higher rate than non-indigenous Australians. Of these diseases, the group of mental health disorders has one of the highest disparity ratio. This group represents disorders relating to stress, anxiety, depression, alcohol and drug use, and the autism spectrum [5]. To understand the impact of trauma, the issues raised above may be viewed through Historical Trauma theory. This conceptual theory is based on the premise that where a particular population has been historically subjected to long periods of mass trauma

#### **Figure 1.**

*Incidence of higher levels of distress among indigenous Australians compared to non-indigenous population. For indigenous Australians, the comparative distress levels are not only higher for all the four reported time periods but also show a trend of increasing levels of disparity for each consecutive period. Data for this chart were derived from Australian government report: Overcoming indigenous disadvantage 2016 [7].*

**159**

conclusions.

**1.3 Results**

*Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

**1.2 Methodology**

disproportionately high rates of fatal self-harm [11, 12].

article focusses upon retrograde amnesia of psychogenic origins.

of amnesia compared to non-indigenous counterparts.

Data used in this article has been derived from Australian Government sources with the figures extrapolated from mental health statistics, in particular mood and neurotic disorders in which dissociative and psychogenic amnesia appears to draw

Indigenous Australians have a higher incidence of distress indicative of social and psychological trauma than non-indigenous Australians. The legacy of trauma continues to exist in indigenous life with lived experience of psychological, sexual and physical abuse (including domestic violence), alcohol and substance abuse, over-policing, dissociation from family due to out-of-home care, continuing discrimination and racism, perpetuating the cycle. The effects are hard to quantify as directly supporting statistical evidence is limited [9, 10]. The greater incidence of distress trauma present in indigenous communities correlates to a higher incidence

(such as colonialism, genocide, slavery, and abuse) then higher incidents of poor health outcomes remain present for many generations to follow [8]. In Australia, this is evidenced by the health disparities currently present [9, 10]. Once primary trauma occurs, the intergenerational effect is amplified by the risks associated with increased vulnerability to secondary trauma identified above. As a result, a pattern of trauma is often established in family and community groups which can be viewed through the current statistics that evidence Australian indigenous children end up in out-of-home care at a greater rate than non-indigenous children and

For this review, research papers were retrieved from the following databases and search engines: the Centre for Independent Studies (CIS), ProQuest, PubMed, ScienceDirect, Scopus, and Springer Link. The following: "trauma," "childhood trauma," "intergenerational trauma," "indigenous," "aboriginal," "retrograde amnesia of psychogenic origins," "dissociative and psychogenic amnesia," "mental health," "indigenous connection to country" together with "quantitative," "statistical" and "social neuroscience" were used as keywords to filter results. Other keywords to filter results were "over policing," "detention," and "close the gap." Search areas were restricted to clinical neurological science and sociology reporting on amnesia across indigenous Australians with results analyzed on the basis of the last two decades, geographical location, and types of intervention. Statistical evidence was sought from the Australian Bureau of Statistics (ABS) National Health Survey, 2014–2015, National Aboriginal and Torres Strait Islander Social Survey, 2014–2015 and Australian Institute of Health and Welfare (AIHW). Criteria for inclusion in this review were studies from the last two decades to capture political and social changes and were written in the English language. When the effect of mass trauma was analyzed for indigenous Australians on the basis of population and global geographical location, it was observed that New Zealand studies were most relevant to this review. The exclusion criteria were reviews outside recent neurological memory loss and general indigenous research not relevant to Australian indigenous issues and papers not written in English. Research papers were also limited based on health specific records, identification of indigenous people, diagnosis mixed with other preexisting conditions. Also excluded, were reviews relating to memory loss as a result of accidents, sports, and direct physical damage to the brain, as the scope of this

#### *Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

(such as colonialism, genocide, slavery, and abuse) then higher incidents of poor health outcomes remain present for many generations to follow [8]. In Australia, this is evidenced by the health disparities currently present [9, 10]. Once primary trauma occurs, the intergenerational effect is amplified by the risks associated with increased vulnerability to secondary trauma identified above. As a result, a pattern of trauma is often established in family and community groups which can be viewed through the current statistics that evidence Australian indigenous children end up in out-of-home care at a greater rate than non-indigenous children and disproportionately high rates of fatal self-harm [11, 12].

#### **1.2 Methodology**

*Neurological and Mental Disorders*

approaches.

adverse experiences.

across health outcomes [4, 5].

**1.1 Background**

disorders by considering memory disturbances, relationships to functionality and frequency, before turning to aspects of therapeutic interventions and culturally safe

The use of social neuroscience in exploring the incidence of amnesia caused by emotional and psychological trauma among indigenous Australians will provide broader consideration of the causal attributes of more prevalent levels of suffering among indigenous Australians as compared to non-indigenous Australians [1]. Social neuroscience perspectives on childhood trauma unite the concept that the brain responds to stress and abuse, as social behaviors stem from brain development [2]. Consideration may then be given to development of best therapeutic practices to promote healing and recovery from the damage caused to brain development by

It cannot be emphasized enough that the colonialist practices of dispossession, child removal, suppression of indigenous social practices, stolen heritages and oppressive government policies, resulted in long-term intergenerational trauma that is still experienced today [3]. Ongoing social inequalities are particularly apparent

Current statistics indicate there are approximately 800,000 indigenous Australians, equating to 2.8% of the Australian population [6] (**Figure 1**).

The health and welfare outcomes are significantly disproportionate as indigenous Australians experience disease at a far higher rate than non-indigenous Australians. Of these diseases, the group of mental health disorders has one of the highest disparity ratio. This group represents disorders relating to stress, anxiety, depression, alcohol and drug use, and the autism spectrum [5]. To understand the impact of trauma, the issues raised above may be viewed through Historical Trauma theory. This conceptual theory is based on the premise that where a particular population has been historically subjected to long periods of mass trauma

*Incidence of higher levels of distress among indigenous Australians compared to non-indigenous population. For indigenous Australians, the comparative distress levels are not only higher for all the four reported time periods but also show a trend of increasing levels of disparity for each consecutive period. Data for this chart* 

*were derived from Australian government report: Overcoming indigenous disadvantage 2016 [7].*

**158**

**Figure 1.**

For this review, research papers were retrieved from the following databases and search engines: the Centre for Independent Studies (CIS), ProQuest, PubMed, ScienceDirect, Scopus, and Springer Link. The following: "trauma," "childhood trauma," "intergenerational trauma," "indigenous," "aboriginal," "retrograde amnesia of psychogenic origins," "dissociative and psychogenic amnesia," "mental health," "indigenous connection to country" together with "quantitative," "statistical" and "social neuroscience" were used as keywords to filter results. Other keywords to filter results were "over policing," "detention," and "close the gap." Search areas were restricted to clinical neurological science and sociology reporting on amnesia across indigenous Australians with results analyzed on the basis of the last two decades, geographical location, and types of intervention. Statistical evidence was sought from the Australian Bureau of Statistics (ABS) National Health Survey, 2014–2015, National Aboriginal and Torres Strait Islander Social Survey, 2014–2015 and Australian Institute of Health and Welfare (AIHW). Criteria for inclusion in this review were studies from the last two decades to capture political and social changes and were written in the English language. When the effect of mass trauma was analyzed for indigenous Australians on the basis of population and global geographical location, it was observed that New Zealand studies were most relevant to this review.

The exclusion criteria were reviews outside recent neurological memory loss and general indigenous research not relevant to Australian indigenous issues and papers not written in English. Research papers were also limited based on health specific records, identification of indigenous people, diagnosis mixed with other preexisting conditions. Also excluded, were reviews relating to memory loss as a result of accidents, sports, and direct physical damage to the brain, as the scope of this article focusses upon retrograde amnesia of psychogenic origins.

Data used in this article has been derived from Australian Government sources with the figures extrapolated from mental health statistics, in particular mood and neurotic disorders in which dissociative and psychogenic amnesia appears to draw conclusions.

#### **1.3 Results**

Indigenous Australians have a higher incidence of distress indicative of social and psychological trauma than non-indigenous Australians. The legacy of trauma continues to exist in indigenous life with lived experience of psychological, sexual and physical abuse (including domestic violence), alcohol and substance abuse, over-policing, dissociation from family due to out-of-home care, continuing discrimination and racism, perpetuating the cycle. The effects are hard to quantify as directly supporting statistical evidence is limited [9, 10]. The greater incidence of distress trauma present in indigenous communities correlates to a higher incidence of amnesia compared to non-indigenous counterparts.

#### **2. Key concepts in memory and related losses: amnesia**

To better understand the nature of memory and how memory loss occurs in various types of amnesia, existing knowledge about human memory and a description of the various types of amnesia relevant to this article are set out below.

#### **2.1 Memory**

All memory types have two dimensions, time and content. Considering the time dimension, memory is categorized into a further four categories based on its content. Firstly, the shortest term memory type, which lasts a second or less, described as sensory memory, here sensory receptors capture the sensation momentarily to be filed into a longer-term memory section [13]. There are five sensory receptors which provide input to sensory memory: iconic or visual, echoic or auditory, haptic or touch-based, olfactory or smell related, and a taste receptor. Secondly, there is working memory, also referred to as primary or active memory which last less than a minute. Thirdly, there is the long-term memory, the loss of which is essentially the primary subject of this article [13]. The contents of long-term memory are categorized into two main types; one is explicit or conscious memory, sometimes also referred to as declarative memory, and implicit or unconscious memory, also known as procedural memory. The explicit or conscious memory is generally subtyped into episodic memory where events and experience are recorded; and semantic memory where general facts and concepts are recorded. Episodic memory is referred to episodic autobiographical memory (EAM), if the episode recorded relates to personal experiences [14, 15].

Other memory types such as prospective memory relate to processing future tasks and have little to do with recollection of past events. Autonoetic consciousness, however, is regarded as an anchor, or sense of self, in that all past experiences or exposures over a person's lifetime are able to be retrieved and reflected upon [14, 16]. Conversely, semantic memory refers to the process of collecting general knowledge, allowing for recall of rudimentary facts and common knowledge, learned during the course of an individual's existence, not drawn from personal experiences but is interconnected with culture [14].

Independent case studies have demonstrated that both episodic and semantic memories may be lost and, given the right time and circumstances, these memories may be recovered at a later date [14]. In one case it was observed that a patient experiencing retrograde amnesia caused by a mild head trauma exacerbated by work stressors was unable to access episodic and semantic memories. Over a period of several months, the patient was observed to be able to recall some semantics until full access to his blocked memories was established. In this case, to determine full recovery the patient was required to demonstrate competency in three faculties; ability to sense time, be aware of subjective autonoetic chronology and be aware of the presence of his own self through that chronology [14]. Neuroscience research relating to the experience, absorption, and memory of various episodes in life has found little evidence of early infantile episodic memory and given the development of the brain, early episodic and autobiographical memory during infancy does not happen. It is generally agreed that these memories occur after the age of 3 years [15].

For indigenous Australians, associations with family, community, land and wellbeing are crucial; individual land ownership is not an indigenous concept. Memories are formed through "storytelling" as a form of continuous oral tradition of recording and preserving history and importance of connection to land and

**161**

*Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

generations.

**2.2 Amnesia**

and suicidal ideation [21, 22].

*2.2.1 History of amnesia*

country [17]. Intimate knowledge of country forms a strong connection that is inherent to indigenous identity and sustains wellbeing across spiritual, physical, social and cultural perspectives. Caring for country means participating in interrelated activities which aim to promote ecological, spiritual and human health and wellbeing. Loss of autonoetic consciousness interrupts such connection to country and as such, impacts upon health and wellbeing, not just for an individual but often for a community [1, 18]. The impact of amnesia results in lost inheritance for future

Whilst it is acknowledged that memory loss may occur as a result of accidents, sports, and direct physical damage to the brain, the scope of this article is centered upon retrograde amnesia of psychogenic origins. Retrograde amnesia is the inability to recall long-term memory, mainly episodic and autobiographical, and is caused by extreme psychological trauma typified by that experienced by indigenous Australians [19]. In severe cases, anterograde amnesia may occur preventing the formation of any further memories after the experience of an episode of severe psychogenic trauma and, although atypical, may also be accompanied by loss of semantic and factual memories [19]. Dissociative amnesia, a subtype of psychogenic amnesia, is usually triggered by a traumatic event and is illustrated by retrospective memory gaps, the inability to recall personal information, often of a traumatic or stressful nature and is too explicit to be ascribed to forgetfulness or fatigue [20]. This article will also specifically consider indigenous childhood trauma of psychogenic origins that causes the removal of painful memories from parts of the brain that are responsible for memory function. The removal of such painful memories is considered a defense mechanism to extreme emotional and psychological stress. Dissociative amnesia may also have accompanying indications of depression and anxiety, with associated displays of impulsive aggressive behaviour, self-mutilation

Historically, incidents of amnesia associated with memory lapses and forgetfulness have been linked to physical, emotional, and spiritual welfare and often hypothesized through a philosophical lens [23]. Historically, memory loss was attributed to neurological disorders and physical head injuries, metabolic dysregulation, substance abuse, other acute or chronic brain illnesses. Following much debate, amnesia was identified as a memory disorder with further specificity distinguishing retrograde and anterograde categories [23]. Amnesia as a clinical feature was critical to the development of notions of dissociation of conscious from subconscious recall, and differentiation of neurogenically-based from psychogenic-

based amnesia became central to understanding post-traumatic states [21].

Memory functionality has been found to improve when events recorded by the brain are emotionally arousing. These events tend to enable the human brain to absorb and recall events more effectively, over a longer period of time. The use of corticosteroids or cortisol, the main form of long-term stress hormones, has been considered to enhance or increase the brain's memory capacity [24]. Conversely, persistently high levels of the stress hormone cortisol, common among indigenous

*2.2.2 Neurological observations of stress-related amnesia*

country [17]. Intimate knowledge of country forms a strong connection that is inherent to indigenous identity and sustains wellbeing across spiritual, physical, social and cultural perspectives. Caring for country means participating in interrelated activities which aim to promote ecological, spiritual and human health and wellbeing. Loss of autonoetic consciousness interrupts such connection to country and as such, impacts upon health and wellbeing, not just for an individual but often for a community [1, 18]. The impact of amnesia results in lost inheritance for future generations.

#### **2.2 Amnesia**

*Neurological and Mental Disorders*

**2.1 Memory**

experiences [14, 15].

**2. Key concepts in memory and related losses: amnesia**

To better understand the nature of memory and how memory loss occurs in various types of amnesia, existing knowledge about human memory and a description of the various types of amnesia relevant to this article are set out below.

All memory types have two dimensions, time and content. Considering the time dimension, memory is categorized into a further four categories based on its content. Firstly, the shortest term memory type, which lasts a second or less, described as sensory memory, here sensory receptors capture the sensation momentarily to be filed into a longer-term memory section [13]. There are five sensory receptors which provide input to sensory memory: iconic or visual, echoic or auditory, haptic or touch-based, olfactory or smell related, and a taste receptor. Secondly, there is working memory, also referred to as primary or active memory which last less than a minute. Thirdly, there is the long-term memory, the loss of which is essentially the primary subject of this article [13]. The contents of long-term memory are categorized into two main types; one is explicit or conscious memory, sometimes also referred to as declarative memory, and implicit or unconscious memory, also known as procedural memory. The explicit or conscious memory is generally subtyped into episodic memory where events and experience are recorded; and semantic memory where general facts and concepts are recorded. Episodic memory is referred to episodic autobiographical memory (EAM), if the episode recorded relates to personal

Other memory types such as prospective memory relate to processing future tasks and have little to do with recollection of past events. Autonoetic consciousness, however, is regarded as an anchor, or sense of self, in that all past experiences or exposures over a person's lifetime are able to be retrieved and reflected upon [14, 16]. Conversely, semantic memory refers to the process of collecting general knowledge, allowing for recall of rudimentary facts and common knowledge, learned during the course of an individual's existence, not drawn from personal

Independent case studies have demonstrated that both episodic and semantic memories may be lost and, given the right time and circumstances, these memories may be recovered at a later date [14]. In one case it was observed that a patient experiencing retrograde amnesia caused by a mild head trauma exacerbated by work stressors was unable to access episodic and semantic memories. Over a period of several months, the patient was observed to be able to recall some semantics until full access to his blocked memories was established. In this case, to determine full recovery the patient was required to demonstrate competency in three faculties; ability to sense time, be aware of subjective autonoetic chronology and be aware of the presence of his own self through that chronology [14]. Neuroscience research relating to the experience, absorption, and memory of various episodes in life has found little evidence of early infantile episodic memory and given the development of the brain, early episodic and autobiographical memory during infancy does not happen. It is generally agreed that these memories occur after the

For indigenous Australians, associations with family, community, land and wellbeing are crucial; individual land ownership is not an indigenous concept. Memories are formed through "storytelling" as a form of continuous oral tradition of recording and preserving history and importance of connection to land and

experiences but is interconnected with culture [14].

**160**

age of 3 years [15].

Whilst it is acknowledged that memory loss may occur as a result of accidents, sports, and direct physical damage to the brain, the scope of this article is centered upon retrograde amnesia of psychogenic origins. Retrograde amnesia is the inability to recall long-term memory, mainly episodic and autobiographical, and is caused by extreme psychological trauma typified by that experienced by indigenous Australians [19]. In severe cases, anterograde amnesia may occur preventing the formation of any further memories after the experience of an episode of severe psychogenic trauma and, although atypical, may also be accompanied by loss of semantic and factual memories [19]. Dissociative amnesia, a subtype of psychogenic amnesia, is usually triggered by a traumatic event and is illustrated by retrospective memory gaps, the inability to recall personal information, often of a traumatic or stressful nature and is too explicit to be ascribed to forgetfulness or fatigue [20]. This article will also specifically consider indigenous childhood trauma of psychogenic origins that causes the removal of painful memories from parts of the brain that are responsible for memory function. The removal of such painful memories is considered a defense mechanism to extreme emotional and psychological stress. Dissociative amnesia may also have accompanying indications of depression and anxiety, with associated displays of impulsive aggressive behaviour, self-mutilation and suicidal ideation [21, 22].

#### *2.2.1 History of amnesia*

Historically, incidents of amnesia associated with memory lapses and forgetfulness have been linked to physical, emotional, and spiritual welfare and often hypothesized through a philosophical lens [23]. Historically, memory loss was attributed to neurological disorders and physical head injuries, metabolic dysregulation, substance abuse, other acute or chronic brain illnesses. Following much debate, amnesia was identified as a memory disorder with further specificity distinguishing retrograde and anterograde categories [23]. Amnesia as a clinical feature was critical to the development of notions of dissociation of conscious from subconscious recall, and differentiation of neurogenically-based from psychogenicbased amnesia became central to understanding post-traumatic states [21].

#### *2.2.2 Neurological observations of stress-related amnesia*

Memory functionality has been found to improve when events recorded by the brain are emotionally arousing. These events tend to enable the human brain to absorb and recall events more effectively, over a longer period of time. The use of corticosteroids or cortisol, the main form of long-term stress hormones, has been considered to enhance or increase the brain's memory capacity [24]. Conversely, persistently high levels of the stress hormone cortisol, common among indigenous people can be detrimental to long-term health, mental health and, wellbeing of the individual and community [25, 26]. Episodic memory appears to be affected when the Hypothalamus-pituitary-adrenal (HPA) axis records higher amounts of glucocorticoids, released from the adrenal cortex, when stress is experienced which impacts the regions inside the brain. Central to the above is that episodic memory is not just impaired, but more specifically its access and retrieval is temporarily blocked [27].

#### *2.2.3 Beneficial effects of amnesia*

The repression of memory, whether consciously practiced or chemically induced, is considered to be a suitable coping mechanism for trauma-related or acute stress and has been observed to be good practice for sufferers of myocardial infarction [28]. The benefits of memory repression were realized whilst researching prevention, delayed onset, or reduction in the severity of post-traumatic stress disorders (PTSD) [29]. Although trauma-induced amnesia does not increase a person's functionality, intellect or powers of execution, it has been found to reduce stress disorders. The defense mechanism in the brain that induces amnesia after a severe episode of trauma has the protective effect of reducing the likelihood of PTSD, autism spectrum disorder and other associated side effects [29].

#### *2.2.4 Treatments of psychogenic and dissociative amnesia*

No agreed treatment is available for psychogenic dissociative amnesia nor any methodology in place that may lead to rehabilitation. It is suggested that this is one area where complimentary intensive research in neurophysiology may improve understanding of the disorder and produce a feasible solution to improve the quality of life for those afflicted [30]. The inherent danger in dissociative amnesia is that it statistically points to increased risk of self-harm, suicide, and life-long loss of cognitive functionality. The detection and prevalence of dissociative amnesia varies broadly nationally and internationally, making it harder to define and detect let alone attempt to mitigate its effects [30].

Consequently, this article will correlate neurophysiological research with social and demographic research pertaining to indigenous Australians to detect the presence and epidemiology of psychogenic amnesiacs. The platform of social neuroscience, where such convergence occurs, is considered a suitable area of study as outlined further below.

#### **3. Social neuroscience and its relevance**

Humans are social in nature and create evolving social structures based on an individual social grouping and the creation and evolution of accompanying cultures. These social structures have influenced the evolution of human neurobiological systems and accompanying effects on genes, cells, neural networks, and hormones. Social neuroscience is a study of the connection of the two systems as they coexist and co-influence [31]. Human neurobiological makeup has assisted in the various social constructs humans have built around themselves, which have then influenced and mutated human biology [31]. Social neuroscience is a relatively new area of academic inquiry which allows for greater understanding into the codependency and confluence of biological and social sciences. Insights into the cause and effect of psychological events on human neurophysiology validate the need for further research into social neuroscience [32].

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*Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

lectual capabilities [34].

**4. Social, community and belief considerations**

should be considered in any treatment plan [37].

solutions to better health outcomes.

understand the impact of amnesia [41].

Neuroscience research provides evidence that traumatic psychogenic amnesia, not directly associated with physical brain damage, impacts upon brain functions following the use of a neuroimaging technique called positron emission tomography (PET) [33]. It has been observed that a psychogenic amnesiac has different parts of the brain activated compared to non-amnesiacs in that the amygdala and other regions of the brain showed increased activity [19]. This leads to the suggestion that limbic functions and limbic cortical functions are affected by psychogenic amnesia and in case studies, patients recorded as having experienced traumatic psychogenic amnesia, also demonstrate cognitive impairments in attention, execution and intel-

Research into trauma related amnesia in relation to indigenous people can be a sensitive issue. Much has been written about indigenous health with criticism around the research methodology, theoretical perspectives, and evaluations of programs. It is clear the "closing the gap" strategy is struggling to have a major impact on the ambitious targets set by the Australian Government [35]. Reflective practices between cultures often present different philosophical and theoretical perspectives and discrete communication and language add complexity to the problems faced. The interpretation of incidence of amnesia among indigenous Australians can aggravate the segregation of the two cultures [36]. Interventions should be in the context of the use of traditional learning processes to view health and wellbeing from traditional healing perspectives with sound solutions for the future [36]. Comparative New Zealand research into therapeutic interventions for indigenous mental health, demonstrated that treatment based on the premise that a holistic view of wellbeing which is congruent with culture, customs and values integrating aspects of spirituality, provides a greater individual sense of self and place, and

Within the last decade, there appears to have been a shift in the narrative around

acknowledging that not all aspects of indigenous culture is positive. Recent discourse by prominent female indigenous leaders has provided a sincere snapshot into some of the continuing health issues [38]. It is conceded that indigenous communities are often desensitized to a culture of violence, with many assaults going unreported, and violence deemed the norm [39]. It is also felt that the very nature of the traditional culture continues to maintain the dominant rights for men to control women [38]. These adverse aspects of culture are regarded as detrimental to finding

There is an urgent need for better evaluation of indigenous policies and programs nationally to assess outcomes. There is a lack of reliable national data reporting on how health and wellbeing measures are based. Evidence shows that when programs are well researched, supported by effective community targeting and engagement, then outcomes are positive [39]. One example of this is in relation to petrol sniffing and the implementation of OPAL fuel (a low aromatic fuel) substitution for petrol. This program resulted in a dramatic reduction in ailments arising from petrol sniffing [40]. Improved data collection around patient consultation, diagnosis, referrals to specialists, and outcome of referrals is required to better

The concept of culture plays an important part in both the social and biological sciences as culture enables a community to make sense of their world and impacts treatment outcomes. Research provides that the biogenetic, environmental and cultural influences impact collectively on cognitive development affecting

#### *Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

*Neurological and Mental Disorders*

*2.2.3 Beneficial effects of amnesia*

blocked [27].

people can be detrimental to long-term health, mental health and, wellbeing of the individual and community [25, 26]. Episodic memory appears to be affected when the Hypothalamus-pituitary-adrenal (HPA) axis records higher amounts of glucocorticoids, released from the adrenal cortex, when stress is experienced which impacts the regions inside the brain. Central to the above is that episodic memory is not just impaired, but more specifically its access and retrieval is temporarily

The repression of memory, whether consciously practiced or chemically induced, is considered to be a suitable coping mechanism for trauma-related or acute stress and has been observed to be good practice for sufferers of myocardial infarction [28]. The benefits of memory repression were realized whilst researching prevention, delayed onset, or reduction in the severity of post-traumatic stress disorders (PTSD) [29]. Although trauma-induced amnesia does not increase a person's functionality, intellect or powers of execution, it has been found to reduce stress disorders. The defense mechanism in the brain that induces amnesia after a severe episode of trauma has the protective effect of reducing the likelihood of

PTSD, autism spectrum disorder and other associated side effects [29].

No agreed treatment is available for psychogenic dissociative amnesia nor any methodology in place that may lead to rehabilitation. It is suggested that this is one area where complimentary intensive research in neurophysiology may improve understanding of the disorder and produce a feasible solution to improve the quality of life for those afflicted [30]. The inherent danger in dissociative amnesia is that it statistically points to increased risk of self-harm, suicide, and life-long loss of cognitive functionality. The detection and prevalence of dissociative amnesia varies broadly nationally and internationally, making it harder to define and detect let

Consequently, this article will correlate neurophysiological research with social and demographic research pertaining to indigenous Australians to detect the presence and epidemiology of psychogenic amnesiacs. The platform of social neuroscience, where such convergence occurs, is considered a suitable area of study

Humans are social in nature and create evolving social structures based on an individual social grouping and the creation and evolution of accompanying cultures. These social structures have influenced the evolution of human neurobiological systems and accompanying effects on genes, cells, neural networks, and hormones. Social neuroscience is a study of the connection of the two systems as they coexist and co-influence [31]. Human neurobiological makeup has assisted in the various social constructs humans have built around themselves, which have then influenced and mutated human biology [31]. Social neuroscience is a relatively new area of academic inquiry which allows for greater understanding into the codependency and confluence of biological and social sciences. Insights into the cause and effect of psychological events on human neurophysiology validate the need for

*2.2.4 Treatments of psychogenic and dissociative amnesia*

alone attempt to mitigate its effects [30].

**3. Social neuroscience and its relevance**

further research into social neuroscience [32].

as outlined further below.

**162**

Neuroscience research provides evidence that traumatic psychogenic amnesia, not directly associated with physical brain damage, impacts upon brain functions following the use of a neuroimaging technique called positron emission tomography (PET) [33]. It has been observed that a psychogenic amnesiac has different parts of the brain activated compared to non-amnesiacs in that the amygdala and other regions of the brain showed increased activity [19]. This leads to the suggestion that limbic functions and limbic cortical functions are affected by psychogenic amnesia and in case studies, patients recorded as having experienced traumatic psychogenic amnesia, also demonstrate cognitive impairments in attention, execution and intellectual capabilities [34].

#### **4. Social, community and belief considerations**

Research into trauma related amnesia in relation to indigenous people can be a sensitive issue. Much has been written about indigenous health with criticism around the research methodology, theoretical perspectives, and evaluations of programs. It is clear the "closing the gap" strategy is struggling to have a major impact on the ambitious targets set by the Australian Government [35]. Reflective practices between cultures often present different philosophical and theoretical perspectives and discrete communication and language add complexity to the problems faced. The interpretation of incidence of amnesia among indigenous Australians can aggravate the segregation of the two cultures [36]. Interventions should be in the context of the use of traditional learning processes to view health and wellbeing from traditional healing perspectives with sound solutions for the future [36]. Comparative New Zealand research into therapeutic interventions for indigenous mental health, demonstrated that treatment based on the premise that a holistic view of wellbeing which is congruent with culture, customs and values integrating aspects of spirituality, provides a greater individual sense of self and place, and should be considered in any treatment plan [37].

Within the last decade, there appears to have been a shift in the narrative around acknowledging that not all aspects of indigenous culture is positive. Recent discourse by prominent female indigenous leaders has provided a sincere snapshot into some of the continuing health issues [38]. It is conceded that indigenous communities are often desensitized to a culture of violence, with many assaults going unreported, and violence deemed the norm [39]. It is also felt that the very nature of the traditional culture continues to maintain the dominant rights for men to control women [38]. These adverse aspects of culture are regarded as detrimental to finding solutions to better health outcomes.

There is an urgent need for better evaluation of indigenous policies and programs nationally to assess outcomes. There is a lack of reliable national data reporting on how health and wellbeing measures are based. Evidence shows that when programs are well researched, supported by effective community targeting and engagement, then outcomes are positive [39]. One example of this is in relation to petrol sniffing and the implementation of OPAL fuel (a low aromatic fuel) substitution for petrol. This program resulted in a dramatic reduction in ailments arising from petrol sniffing [40]. Improved data collection around patient consultation, diagnosis, referrals to specialists, and outcome of referrals is required to better understand the impact of amnesia [41].

The concept of culture plays an important part in both the social and biological sciences as culture enables a community to make sense of their world and impacts treatment outcomes. Research provides that the biogenetic, environmental and cultural influences impact collectively on cognitive development affecting

behaviour [42]. It cannot be emphasized enough that through culture, people are able to place themselves and self-identify, as such traditional healing methods should form part of health strategies and be framed through cultural messaging [43]. It has been suggested that two fields of research practice have dominated debates around health and wellbeing, one view suggests that factors such as income, socioeconomic hierarchy, and social status provide indicators of risk of disease, the second view, held by health psychologists, anthropologists and sociologists, is that risk of disease is associated with stressors and the ability of an individual or community to cope with such stressors [32]. Therefore health and wellbeing are impacted by historical legacies and politics; and the passage of time directly affects how culture shapes health trends in relation to indigenous people.

#### **5. Incidence, detection, and impact of amnesia**

Testing for amnesia is often unreliable as it is frequently associated with cognitive dysfunction identified through impairment of learning and executive functions [44]. Cognitive dysfunction is also ubiquitous with high rates of poor health, diseases, substance abuse, domestic violence, psychological stress, and trauma, as reported widely among indigenous Australians. Tests are also often based on Western premise and not tuned for cultural nuances [45]. Alcohol and substance abuse, in general, is one of the most reported concerns among indigenous Australians with misuse often resulting in impairment and toxic harm to organs and tissues, with premature aging and death. Being in a state of intoxication diminishes coordination, cognition, perception and promotes dependency [46]. It has been established that alcohol abuse alters the structure of the brain through degeneration of the cerebral cortex, and causes changes to the hypothalamus and cerebellum [47]. These changes directly impact cognitive processes associated with learning, memory, attention, rational thinking, and impulse control [48, 49]. The abuse of alcohol may cause complications giving rise to neuropsychological disorders, cancer, cardiovascular, diabetes and infectious diseases, injuries whilst intoxicated, and fetal disorders [44, 47]. Poverty and economic stress arising from poor educational outcomes, and unemployment can cause additional psychogenic trauma impacting mental health causing anxiety and depression [41]. As previously outlined, stress triggers hormonal action on the nervous system to produce a biological uninhibited reaction which often translates into violence or abuse. Continuously high stress levels lead to heightened states of hypersensitivity undermining positive health leading to mood disorders such as depression, anxiety and aggression, diabetes and high blood pressure and potentially resultant amnesia [50].

#### **6. Neurophysiological research**

Recent research into dissociative identity disorders supports the finding that highly stressful events during childhood development produce a neurological response to intolerable stress which results in the deconstruction of self-identity [51]. Stress-induced trauma may arise from physical and emotional abuse or neglect, disturbed attachment, and boundary violations with the resultant effect amplified as a result of familial, societal and cultural factors [52]. As a biopsychosocial concept, dissociative identity disorder has been validated as a chronic psychiatric disorder arising from intolerable stress and trauma grounded on interpersonal non-assimilation, cognitive and neurobiological responses and as such warrants further comparative research [51].

**165**

*Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

Research has provided insights into how stress interacts with long-term potentiation (LTP), long-term depression (LTD), stress, and memory on the hippocampus, amygdala and prefrontal cortex [53]. These three regions of the brain are impacted in time from stress-related, trauma-inducing events so that immediate impact is temporarily followed by a medium-term, then a longer term effect [54]. In relation to the hippocampus, the LTP is engaged and activated for a short period of time. After this early period lasting no more than a few minutes, LTP activity is blocked and a period of memory consolidation occurs for up to half an hour [54, 55]. During this period of consolidation new memories are suppressed and LTP is disengaged. In the amygdala region, LTP is engaged for a longer-period and emergency decision making is enabled and action is taken [54]. The prefrontal cortex reacts differently compared to the hippocampus and amygdala in that LTP is temporarily impaired, attention is divided and multitasking is enabled. After a period lasting a few minutes to an hour normal LTP induction is restored. These concurrent effects on the three parts of the brain induced by traumatic events not only show how strong psychological and emotional events induce high levels of stress, resulting in short-, medium- and long-term effects but also result in longer-term phenotype changes in their physiological structure [54]. Further evidence of the impact of trauma on neurophysiological structures is provided by PET data, which illustrates that the right hemisphere of the brain is affected by these events and visual areas of the

brain are activated, directly related to the extent of trauma [19, 33, 34].

In severe cases of trauma-related stress, both retrograde and anterograde memories are affected along with overall impairment of mental and physical health [26, 55]. Studies relating to the frequency of dissociative and psychogenic amnesia have been carried out in 16 countries with rates of prevalence in different countries varying from 0.2 to 7.3% [56]. This large variation in the epidemiology may partly be explained by a lack of standard testing. Therefore, combining social research with neuroimaging data and neurobiological studies of this disorder is suggested to improve understanding of the debilitating impact on its sufferers, and indigenous

Access to appropriate treatment is problematic given the lack of accurate testing, diagnosis and reporting. Frequently, the correlation between a patient's symptoms and traumatic experiences are not explored in depth as existing diagnostic tools are used to analyze and problem-solve which may only result in partial treatments [44]. Often trauma is treated by prescribing medicines for insomnia, anxiety and depression without understanding the etiology of the trauma condition [12, 51, 52]. There is also an increase in interventions from agencies in relation to emotional abuse, neglect and exposure to domestic violence and the need to mitigate risk to children. Again, although the paramount protection of children is the overriding concern, interventions do not address underlying issues associated with trauma and to a

According to the 2012–2013 Australian Aboriginal and Torres Strait Islander Health Survey (AATSIHS) 30% of people over 18 years old reported high or very high levels of psychological distress. Indigenous people were approximately three times likely to have experienced very high levels of psychological distress across age groups [57]. As previously mentioned, stress can impact on cognitive function and produce mental health issues. Cognitive processes affected in mood disorders include impairment of working memory, abstract reasoning, sustained attention, visuomotor skills and verbal memory [45, 53, 58]. **Figure 2** below demonstrates

**7. Epidemiology of psychogenic amnesia**

Australian communities in general [56].

certain extent, perpetuate the effects [50].

#### *Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

*Neurological and Mental Disorders*

behaviour [42]. It cannot be emphasized enough that through culture, people are able to place themselves and self-identify, as such traditional healing methods should form part of health strategies and be framed through cultural messaging [43]. It has been suggested that two fields of research practice have dominated debates around health and wellbeing, one view suggests that factors such as income, socioeconomic hierarchy, and social status provide indicators of risk of disease, the second view, held by health psychologists, anthropologists and sociologists, is that risk of disease is associated with stressors and the ability of an individual or community to cope with such stressors [32]. Therefore health and wellbeing are impacted by historical legacies and politics; and the passage of time directly affects

how culture shapes health trends in relation to indigenous people.

Testing for amnesia is often unreliable as it is frequently associated with cognitive dysfunction identified through impairment of learning and executive functions [44]. Cognitive dysfunction is also ubiquitous with high rates of poor health, diseases, substance abuse, domestic violence, psychological stress, and trauma, as reported widely among indigenous Australians. Tests are also often based on Western premise and not tuned for cultural nuances [45]. Alcohol and substance abuse, in general, is one of the most reported concerns among indigenous Australians with misuse often resulting in impairment and toxic harm to organs and tissues, with premature aging and death. Being in a state of intoxication diminishes coordination, cognition, perception and promotes dependency [46]. It has been established that alcohol abuse alters the structure of the brain through degeneration of the cerebral cortex, and causes changes to the hypothalamus and cerebellum [47]. These changes directly impact cognitive processes associated with learning, memory, attention, rational thinking, and impulse control [48, 49]. The abuse of alcohol may cause complications giving rise to neuropsychological disorders, cancer, cardiovascular, diabetes and infectious diseases, injuries whilst intoxicated, and fetal disorders [44, 47]. Poverty and economic stress arising from poor educational outcomes, and unemployment can cause additional psychogenic trauma impacting mental health causing anxiety and depression [41]. As previously outlined, stress triggers hormonal action on the nervous system to produce a biological uninhibited reaction which often translates into violence or abuse. Continuously high stress levels lead to heightened states of hypersensitivity undermining positive health leading to mood disorders such as depression, anxiety and aggression, diabetes and

**5. Incidence, detection, and impact of amnesia**

high blood pressure and potentially resultant amnesia [50].

Recent research into dissociative identity disorders supports the finding that highly stressful events during childhood development produce a neurological response to intolerable stress which results in the deconstruction of self-identity [51]. Stress-induced trauma may arise from physical and emotional abuse or neglect, disturbed attachment, and boundary violations with the resultant effect amplified as a result of familial, societal and cultural factors [52]. As a biopsychosocial concept, dissociative identity disorder has been validated as a chronic psychiatric disorder arising from intolerable stress and trauma grounded on interpersonal non-assimilation, cognitive and neurobiological responses and as such warrants

**6. Neurophysiological research**

further comparative research [51].

**164**

Research has provided insights into how stress interacts with long-term potentiation (LTP), long-term depression (LTD), stress, and memory on the hippocampus, amygdala and prefrontal cortex [53]. These three regions of the brain are impacted in time from stress-related, trauma-inducing events so that immediate impact is temporarily followed by a medium-term, then a longer term effect [54]. In relation to the hippocampus, the LTP is engaged and activated for a short period of time. After this early period lasting no more than a few minutes, LTP activity is blocked and a period of memory consolidation occurs for up to half an hour [54, 55]. During this period of consolidation new memories are suppressed and LTP is disengaged. In the amygdala region, LTP is engaged for a longer-period and emergency decision making is enabled and action is taken [54]. The prefrontal cortex reacts differently compared to the hippocampus and amygdala in that LTP is temporarily impaired, attention is divided and multitasking is enabled. After a period lasting a few minutes to an hour normal LTP induction is restored. These concurrent effects on the three parts of the brain induced by traumatic events not only show how strong psychological and emotional events induce high levels of stress, resulting in short-, medium- and long-term effects but also result in longer-term phenotype changes in their physiological structure [54]. Further evidence of the impact of trauma on neurophysiological structures is provided by PET data, which illustrates that the right hemisphere of the brain is affected by these events and visual areas of the brain are activated, directly related to the extent of trauma [19, 33, 34].

#### **7. Epidemiology of psychogenic amnesia**

In severe cases of trauma-related stress, both retrograde and anterograde memories are affected along with overall impairment of mental and physical health [26, 55]. Studies relating to the frequency of dissociative and psychogenic amnesia have been carried out in 16 countries with rates of prevalence in different countries varying from 0.2 to 7.3% [56]. This large variation in the epidemiology may partly be explained by a lack of standard testing. Therefore, combining social research with neuroimaging data and neurobiological studies of this disorder is suggested to improve understanding of the debilitating impact on its sufferers, and indigenous Australian communities in general [56].

Access to appropriate treatment is problematic given the lack of accurate testing, diagnosis and reporting. Frequently, the correlation between a patient's symptoms and traumatic experiences are not explored in depth as existing diagnostic tools are used to analyze and problem-solve which may only result in partial treatments [44]. Often trauma is treated by prescribing medicines for insomnia, anxiety and depression without understanding the etiology of the trauma condition [12, 51, 52]. There is also an increase in interventions from agencies in relation to emotional abuse, neglect and exposure to domestic violence and the need to mitigate risk to children. Again, although the paramount protection of children is the overriding concern, interventions do not address underlying issues associated with trauma and to a certain extent, perpetuate the effects [50].

According to the 2012–2013 Australian Aboriginal and Torres Strait Islander Health Survey (AATSIHS) 30% of people over 18 years old reported high or very high levels of psychological distress. Indigenous people were approximately three times likely to have experienced very high levels of psychological distress across age groups [57]. As previously mentioned, stress can impact on cognitive function and produce mental health issues. Cognitive processes affected in mood disorders include impairment of working memory, abstract reasoning, sustained attention, visuomotor skills and verbal memory [45, 53, 58]. **Figure 2** below demonstrates

#### **Figure 2.**

*Levels of distress in indigenous versus non-indigenous Australians across time and age-groups. Indigenous Australians aged 35–44 years record the highest levels of distress and non-indigenous Australians aged 55+ years record the lowest levels of distress. As time passes, stress levels appear to be increasing in all age groups in indigenous Australians and decreasing or stable in non-indigenous. Data for this chart were derived from Australian government report: Overcoming indigenous disadvantage 2016 [7].*

varying levels of high distress experienced by various age groups among indigenous and non-indigenous Australians, exemplifying the huge mental health disparity between the two communities.

#### **8. Incidence of psycho-social trauma**

Childhood psychogenic trauma can be experienced in a multitude of ways. Although many indigenous children grow up in stable and loving homes, those exposed to secondary trauma, develop coping mechanisms [59]. Long-term stress arising from direct forms of psychogenic trauma and indirect transgenerational trauma gives rise to a continuous stream of cortisol. These high levels of cortisol result in the body disabling the cortisol receptors in an attempt to disengage itself from painful events. When high levels of cortisol are present in childhood, it results in children feeling withdrawn and inactive with an associated lack of stimulation [25]. Conversely, responding to the similar circumstances of high stress and unabated levels of cortisol, some children may display highly sensitive and alert behavior which eventually takes a toll on their long-term health [25]. In either case, recurring levels of stress produce psychiatric damage that continues into adulthood. The impact is then perpetuated at community levels displaying across their mental and physical health. Further, sensory emotional and physical flashbacks of repeated traumatic experiences including diagnosed post-traumatic stress disorders produce further disordered memory function. Flashbacks are more likely to occur when a person is upset, stressed or aroused by any association with the traumatic event [52].

Within indigenous Australian culture, traditional values still control communities and maintain the dominant rights of indigenous males over females. Negative aspects of this culture are associated with the intersection of customs and law whereby customary law allows for the sexual assault of under-age girls who are "promised wives" to men and suffer an early cessation of childhood [60]. Family violence also has a significant impact on the health and welfare of individuals,

**167**

and reduction in costs [63].

**Figure 3.**

*Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

*Overcoming indigenous disadvantage 2016 [7].*

families, and communities [38, 61]. In some Australian jurisdictions, police records indicate indigenous women were physically assaulted up to 11.4 times more frequently than non-Indigenous women with reports of domestic and family violence by a current partner also considerably higher than for non-indigenous women [7]. Hospitalizations for indigenous women for non-fatal family violence-related assaults were also significantly higher at 32 times the rate of non-Indigenous females [7]. Hospitalizations among indigenous population due to mental health disorders are twice as high as non-indigenous Australians as shown in **Figure 3** below.

*All mental health hospitalizations for indigenous versus non-indigenous Australians over time indicating significant variation in population. Data for this chart were derived from Australian government report:* 

In understanding the ongoing legacy related to trauma, consideration needs to be given to the number of children in kinship care. Kinship carers are often in an older age group, are economically poorer, with reduced health, and lower levels of education than foster carers and may appear to perpetuate the pattern of disadvantage [62]. The number of indigenous children in kinship care has grown at more than twice the rate of children in foster and residential care with some suggestions that this has been driven by increased demands for care, a shortage of foster carers,

Attention must also be placed on the enduring disproportionate rates of indigenous arrests, detention, and over-policing evident in many indigenous communities. The 1991 establishment of the Royal Commission into Aboriginal Deaths in Custody confirms that treatment of indigenous people in the criminal justice system was considered of national importance and left no doubt as to concerns about inappropriate violence perpetrated by Police [64–66]. More recent concerns raised by the New South Wales Ombudsman still suggest a disproportionate level of

interaction, over-policing and use of Tasers against indigenous people [67].

Research has shown that often individual experiences of trauma underscore difficulties in recovery as the effects of trauma compound within a community on which an individual has depended, and the community becomes fragmented and disconnected [9]. An individual diagnosis of psychogenic amnesia may be better served if consideration is given to collective community trauma; individual

**9. What can be done and what has been achieved**

#### **Figure 3.**

*Neurological and Mental Disorders*

between the two communities.

**Figure 2.**

the traumatic event [52].

**8. Incidence of psycho-social trauma**

*Australian government report: Overcoming indigenous disadvantage 2016 [7].*

varying levels of high distress experienced by various age groups among indigenous and non-indigenous Australians, exemplifying the huge mental health disparity

*Levels of distress in indigenous versus non-indigenous Australians across time and age-groups. Indigenous Australians aged 35–44 years record the highest levels of distress and non-indigenous Australians aged 55+ years record the lowest levels of distress. As time passes, stress levels appear to be increasing in all age groups in indigenous Australians and decreasing or stable in non-indigenous. Data for this chart were derived from* 

Childhood psychogenic trauma can be experienced in a multitude of ways. Although many indigenous children grow up in stable and loving homes, those exposed to secondary trauma, develop coping mechanisms [59]. Long-term stress arising from direct forms of psychogenic trauma and indirect transgenerational trauma gives rise to a continuous stream of cortisol. These high levels of cortisol result in the body disabling the cortisol receptors in an attempt to disengage itself from painful events. When high levels of cortisol are present in childhood, it results in children feeling withdrawn and inactive with an associated lack of stimulation [25]. Conversely, responding to the similar circumstances of high stress and unabated levels of cortisol, some children may display highly sensitive and alert behavior which eventually takes a toll on their long-term health [25]. In either case, recurring levels of stress produce psychiatric damage that continues into adulthood. The impact is then perpetuated at community levels displaying across their mental and physical health. Further, sensory emotional and physical flashbacks of repeated traumatic experiences including diagnosed post-traumatic stress disorders produce further disordered memory function. Flashbacks are more likely to occur when a person is upset, stressed or aroused by any association with

Within indigenous Australian culture, traditional values still control communities and maintain the dominant rights of indigenous males over females. Negative aspects of this culture are associated with the intersection of customs and law whereby customary law allows for the sexual assault of under-age girls who are "promised wives" to men and suffer an early cessation of childhood [60]. Family violence also has a significant impact on the health and welfare of individuals,

**166**

*All mental health hospitalizations for indigenous versus non-indigenous Australians over time indicating significant variation in population. Data for this chart were derived from Australian government report: Overcoming indigenous disadvantage 2016 [7].*

families, and communities [38, 61]. In some Australian jurisdictions, police records indicate indigenous women were physically assaulted up to 11.4 times more frequently than non-Indigenous women with reports of domestic and family violence by a current partner also considerably higher than for non-indigenous women [7]. Hospitalizations for indigenous women for non-fatal family violence-related assaults were also significantly higher at 32 times the rate of non-Indigenous females [7]. Hospitalizations among indigenous population due to mental health disorders are twice as high as non-indigenous Australians as shown in **Figure 3** below.

In understanding the ongoing legacy related to trauma, consideration needs to be given to the number of children in kinship care. Kinship carers are often in an older age group, are economically poorer, with reduced health, and lower levels of education than foster carers and may appear to perpetuate the pattern of disadvantage [62]. The number of indigenous children in kinship care has grown at more than twice the rate of children in foster and residential care with some suggestions that this has been driven by increased demands for care, a shortage of foster carers, and reduction in costs [63].

Attention must also be placed on the enduring disproportionate rates of indigenous arrests, detention, and over-policing evident in many indigenous communities. The 1991 establishment of the Royal Commission into Aboriginal Deaths in Custody confirms that treatment of indigenous people in the criminal justice system was considered of national importance and left no doubt as to concerns about inappropriate violence perpetrated by Police [64–66]. More recent concerns raised by the New South Wales Ombudsman still suggest a disproportionate level of interaction, over-policing and use of Tasers against indigenous people [67].

#### **9. What can be done and what has been achieved**

Research has shown that often individual experiences of trauma underscore difficulties in recovery as the effects of trauma compound within a community on which an individual has depended, and the community becomes fragmented and disconnected [9]. An individual diagnosis of psychogenic amnesia may be better served if consideration is given to collective community trauma; individual treatment may result in disconnection from community and loss of self-connection [9]. Studies indicate that adopting evidence-based principles of family and community healing, developed internationally in mass communal disaster situations, may assist in conceptualizing a more informed response to the wellbeing for indigenous Australian communities [9].

It is acknowledged that treatment for trauma-induced amnesia is in early stages of development with robust data not readily available. It is evident that health practitioners working with indigenous Australians affected by trauma need to modify their programs to suit individual traumatic experiences and operate from a "trauma-informed" community perspective [59]. Culturally competent staff accept that trauma is individualized, and that therapeutic care must be customized for the individual to meet holistic and ecological needs [59]. Medical concepts in plain English or local language should replace technical specialist language within cross-cultural settings with the use of "story" central to shared understanding. As a society, we have a responsibility to ensure children have the opportunity to heal from trauma and have a responsibility to ensure all appropriate services and treatment methods are provided to achieve this [42].

In 2015, the Australian Government released the Implementation Plan for the National Aboriginal and Torres Strait Islander Health Plan 2013–2023 which outlines actions and strategies to be undertaken by the Government and other key stakeholders to execute the priorities [68]. Priorities include access to primary health care for early intervention to prevent hospitalizations and avoidable deaths and improved mental health outcomes. The Plan acknowledges that mental health has implications for incidence of domestic violence, substance abuse imprisonment and family disconnections and seeks a reduction in suicide and self-harm rates [68]. The Plan indicates that rates of family and community violence were unchanged between 2002 and 2014–2015 (around 22%), and risky long-term alcohol use in 2014–2015 was similar to 2002 [68]. Of concern, is that the proportion of adults reporting high levels of psychological distress increased from 27% in 2004–2005 to 33% in 2014–2015 (as shown in **Figure 1**),

#### **Figure 4.**

*Mental health hospitalizations by gender for indigenous versus non-indigenous Australians for a reported period and shows increased levels of hospitalizations for both male and female indigenous. Male indigenous hospitalizations show more than twice the level as compared to non-indigenous. Female indigenous have higher levels of hospitalizations than non-indigenous but less than male indigenous which raises possible concerns over reporting. Data for this chart were derived from Australian government report: Overcoming indigenous disadvantage 2016 [7].*

**169**

*Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

for indigenous people [69].

**10. Conclusion**

in any treatment plan.

**Conflict of interest**

**Other declarations**

where quoting other sources.

2002 to 31% in 2014–2015 [5, 68] (**Figure 4**).

and hospitalizations for self-harm increased by 56% over this period. The proportion of adults reporting substance misuse in the previous 12 months increased from 23% in

It has been inspiring to see organizations implement Reconciliation Action Plans driving collective action to implement change for positive indigenous Australian health outcomes. It has been acknowledged that indigenous patient safety is inextricably linked with cultural safety and that currently, no agreed national definition of cultural safety exists [69]. Despite this some organizations have informed the view that cultural safety should be defined as the individual and institutional knowledge, skills, attitudes, and competencies needed to deliver optimal equitable health care

The perspective of trauma-informed health care may change the lens on treatment plans for indigenous people presenting with mental illness [70, 71]. For change to occur, local indigenous communities and regional areas must be in control of determining health needs and responsible for assessing the outcome in conjunction with health professionals [72, 73]. Indigenous Australians have a "right to a good life" and past uncoordinated approaches to tackle the problems of poor

This chapter has considered the psycho-social trauma and epidemiology of amnesia associated with childhood and intergenerational trauma prevalent among indigenous Australians, from the social neuroscience perspective. The legacy of destruction imposed on indigenous Australian by violence and assimilation has had severe long-term consequences contributing to the tragic health inequality present in indigenous Australian's today. The insights derived from this review indicate that the complex effects of psycho-social trauma induced amnesia should be considered

It is clear there is strong need to understand the meaning of trauma recovery in the indigenous context which differs from non-indigenous interpretations, and acknowledgment that wellbeing of indigenous people has to take into account genetic and environmental influences. Indigenous people suffering from psychosocial trauma-induced amnesia often experience additional complex factors of social disconnection. Open discussions need to address cultural dimensions that value past, present and preservation of knowledge. Taking a deeper look at the underlying causal factors of amnesia may allow consideration of a greater range of treatment options across a multitude of social neurological science disciplines may

This chapter generally uses the term "indigenous Australians" to describe Aboriginal and Torres Strait Islander Australians, as Australia's first peoples, and "non-indigenous Australians" to refer to Australians of other backgrounds, except

health outcomes has led to a culture of low expectations [74].

go towards informing funding for further research and training.

The author declares no conflict of interest.

*Neurological and Mental Disorders*

Australian communities [9].

ment methods are provided to achieve this [42].

treatment may result in disconnection from community and loss of self-connection [9]. Studies indicate that adopting evidence-based principles of family and community healing, developed internationally in mass communal disaster situations, may assist in conceptualizing a more informed response to the wellbeing for indigenous

It is acknowledged that treatment for trauma-induced amnesia is in early stages

of development with robust data not readily available. It is evident that health practitioners working with indigenous Australians affected by trauma need to modify their programs to suit individual traumatic experiences and operate from a "trauma-informed" community perspective [59]. Culturally competent staff accept that trauma is individualized, and that therapeutic care must be customized for the individual to meet holistic and ecological needs [59]. Medical concepts in plain English or local language should replace technical specialist language within cross-cultural settings with the use of "story" central to shared understanding. As a society, we have a responsibility to ensure children have the opportunity to heal from trauma and have a responsibility to ensure all appropriate services and treat-

In 2015, the Australian Government released the Implementation Plan for the National Aboriginal and Torres Strait Islander Health Plan 2013–2023 which outlines actions and strategies to be undertaken by the Government and other key stakeholders to execute the priorities [68]. Priorities include access to primary health care for early intervention to prevent hospitalizations and avoidable deaths and improved mental health outcomes. The Plan acknowledges that mental health has implications for incidence of domestic violence, substance abuse imprisonment and family disconnections and seeks a reduction in suicide and self-harm rates [68]. The Plan indicates that rates of family and community violence were unchanged between 2002 and 2014–2015 (around 22%), and risky long-term alcohol use in 2014–2015 was similar to 2002 [68]. Of concern, is that the proportion of adults reporting high levels of psychological distress increased from 27% in 2004–2005 to 33% in 2014–2015 (as shown in **Figure 1**),

**168**

**Figure 4.**

*disadvantage 2016 [7].*

*Mental health hospitalizations by gender for indigenous versus non-indigenous Australians for a reported period and shows increased levels of hospitalizations for both male and female indigenous. Male indigenous hospitalizations show more than twice the level as compared to non-indigenous. Female indigenous have higher levels of hospitalizations than non-indigenous but less than male indigenous which raises possible concerns over reporting. Data for this chart were derived from Australian government report: Overcoming indigenous* 

and hospitalizations for self-harm increased by 56% over this period. The proportion of adults reporting substance misuse in the previous 12 months increased from 23% in 2002 to 31% in 2014–2015 [5, 68] (**Figure 4**).

It has been inspiring to see organizations implement Reconciliation Action Plans driving collective action to implement change for positive indigenous Australian health outcomes. It has been acknowledged that indigenous patient safety is inextricably linked with cultural safety and that currently, no agreed national definition of cultural safety exists [69]. Despite this some organizations have informed the view that cultural safety should be defined as the individual and institutional knowledge, skills, attitudes, and competencies needed to deliver optimal equitable health care for indigenous people [69].

The perspective of trauma-informed health care may change the lens on treatment plans for indigenous people presenting with mental illness [70, 71]. For change to occur, local indigenous communities and regional areas must be in control of determining health needs and responsible for assessing the outcome in conjunction with health professionals [72, 73]. Indigenous Australians have a "right to a good life" and past uncoordinated approaches to tackle the problems of poor health outcomes has led to a culture of low expectations [74].

#### **10. Conclusion**

This chapter has considered the psycho-social trauma and epidemiology of amnesia associated with childhood and intergenerational trauma prevalent among indigenous Australians, from the social neuroscience perspective. The legacy of destruction imposed on indigenous Australian by violence and assimilation has had severe long-term consequences contributing to the tragic health inequality present in indigenous Australian's today. The insights derived from this review indicate that the complex effects of psycho-social trauma induced amnesia should be considered in any treatment plan.

It is clear there is strong need to understand the meaning of trauma recovery in the indigenous context which differs from non-indigenous interpretations, and acknowledgment that wellbeing of indigenous people has to take into account genetic and environmental influences. Indigenous people suffering from psychosocial trauma-induced amnesia often experience additional complex factors of social disconnection. Open discussions need to address cultural dimensions that value past, present and preservation of knowledge. Taking a deeper look at the underlying causal factors of amnesia may allow consideration of a greater range of treatment options across a multitude of social neurological science disciplines may go towards informing funding for further research and training.

#### **Conflict of interest**

The author declares no conflict of interest.

#### **Other declarations**

This chapter generally uses the term "indigenous Australians" to describe Aboriginal and Torres Strait Islander Australians, as Australia's first peoples, and "non-indigenous Australians" to refer to Australians of other backgrounds, except where quoting other sources.

*Neurological and Mental Disorders*

#### **Author details**

Alison Husain1,2

1 Developments in Literacy (DIL Australia), Sydney, Australia

2 New South Wales (NSW) State Government, Office of the Children's Guardian, Sydney, Australia

\*Address all correspondence to: alison.husain@yahoo.com

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**171**

*Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

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trauma in Australian indigenous communities. Australasian Psychiatry. 2009;**17**(1\_suppl):S28-S32. DOI: 10.1080/10398560902948621

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Alison Husain1,2

Sydney, Australia

1 Developments in Literacy (DIL Australia), Sydney, Australia

\*Address all correspondence to: alison.husain@yahoo.com

provided the original work is properly cited.

2 New South Wales (NSW) State Government, Office of the Children's Guardian,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

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ent [Accessed: 06 August 2019]

PMC3120118/

ctg-rs21.pdf

[58] Gould TJ. Addiction and cognition. Addiction Science and Clinical Practice. 2010;**5**(2):4-14. Available from: https:// www.ncbi.nlm.nih.gov/pmc/articles/

[59] Australian Government Australian Institute of Health and Welfare. Studies Resource Sheet no. 21 produced for the Closing the Gap Clearinghouse. Atkinson J. Trauma-Informed Services and Trauma-Specific Care for Indigenous Australian Children. 2013. pp. 4-9. Available from: https:// earlytraumagrief.anu.edu.au/files/

[60] Brown K. Customary Law: Sex with under-age promised wives. Alternative Law Journal. 2007;**32**(1):11-15. DOI: 10.1177/1037969X0703200105

[61] McGlade H. Justice as healing: Developing aboriginal justice models to address child sexual assault. Indigenous Law Bulletin 10. 2007;**7m**(1):10-13. Available from: http://www.austlii.edu. au/au/journals/IndigLawB/2007/59.

*Amnesia among Indigenous Australians DOI: http://dx.doi.org/10.5772/intechopen.89728*

*Neurological and Mental Disorders*

Monograph 105. 2009. p. 4, 11. Available from: https://www.cis.org.au/app/ uploads/2015/07/pm105.pdf

Cambridge prospective memory test (CAMPROMPT). Drug and Alcohol Dependence, Elsevier Science Ltd. 2012;**123**(1-3):207-212. DOI: 10.1016/j.

[49] Chen Y, Yang C, Chen S, Chen Y, Su C. Everyday memory problems in alcohol abuse and dependence:

Frequency, patterns and patient-proxy agreement. Psychiatry Research. Elsevier B.V. 2018;**261**:488-497. DOI: 10.1016/j.psychres.2018.01.016

[50] Higgins D. Protecting children: Evolving systems. Family Matters. Australian Institute of Family Studies. 2011 Dec;**89**:5. Available from: https:// aifs.gov.au/publications/family-matters/

issue-89/protecting-children

[52] Benjamin R, Haliburn J, King S. Humanising Mental Health Care in Australia: A Guide to Trauma-Informed Approaches. London: Routledge; 2019. pp. 11-12

bandc.2007.02.007

10.1155/2007/60803

[53] Lupien SJ, Maheu F, Tu M, Fiocco A, Schramek TE. The effects of stress and stress hormones on human cognition: Implications for the field of brain and cognition. Brain and Cognition. 2007;**65**(3):209-237. DOI: 10.1016/j.

[54] Diamond DM, Campbell AM, Park CR, Halonen J, Zoladz PR. The temporal dynamics model of emotional memory processing: A synthesis on the neurobiological basis of stress-induced Amnesia, flashbulb and traumatic memories, and the Yerkes-Dodson Law. Neural Plasticity. 2007;**2007**(2007):60803. DOI:

S113743

[51] Şar V, Dorahy MJ, Kruger C. Revisiting the etiological aspects of dissociative identity disorder: A biopsychosocial perspective. Psychology Research and Behavior Management. 2017:137-146. DOI: 10.2147/PRBM.

drugalcdep.2011.11.014

[42] Struik A. Treating chronically traumatised children with the sleeping dogs method: Don't let sleeping dogs lie! Children Australia. 2017;**42**(2):93-103.

treatment. Journal of Psychosocial Nursing and Mental Health Services. 2010;**48**(7):27-34. DOI: 10.3928/02793695-20100504-04

[44] Dingwall K, Gray A, Mccarthy A, Delima J, Bowden S. Exploring the reliability and acceptability of cognitive tests for indigenous Australians: A pilot study. BMC Psychology. 2017;**5**(1):1-16. DOI: 10.1186/s40359-017-0195-y

[45] Olga Gray A. Determining

Gray\_A.pdf

acceptable and reliable cognitive testing methods in an Australian Aboriginal population [thesis]. Charles Darwin University; 2015. pp. 1-2, 58-60. Available from: http://espace.cdu.edu. au/eserv/cdu:56203/Thesis\_CDU\_56203\_

[46] World Health Organisation. Global Status Report on Alcohol and Health. Geneva: World Health Organization; 2018. p. 11, 73, 348, 372. Available from: https://apps.who.int/iris/bitstream/han dle/10665/274603/9789241565639-eng. pdf?ua=1 [Accessed: 19 July 2019]

[47] Roussotte FF, Bramen JE, Nunez S, Christopher Q, Lorna C, Smith L, et al. Abnormal brain activation during working memory in children with prenatal exposure to drugs of abuse: The effects of methamphetamine, alcohol, and polydrug exposure. NeuroImage. 2011;**54**(4):3067-3075. DOI: 10.1016/j.

neuroimage.2010.10.072

[48] Heffernan T. Time based

prospective memory deficits associated with binge drinking: Evidence from the

DOI: 10.1017/cha.2017.13

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[55] Sanjay K, Shobini R, Biju S, Gangadhar BN. Widespread cognitive impairment in psychogenic anterograde Amnesia. Psychiatry and Clinical Neurosciences. Blackwell Publishing Asia. 2007;**61**(6):583-586. DOI: 10.1111/j.1440-1819.2007.01735.x

[56] Staniloiu A, Markowitsch HJ. Dissociative amnesia—A challenge to therapy. International Journal of Psychotherapy Practice and Research. 2018;**1**(2):34-47. DOI: 10.14302/ issn.2574-612X.ijpr-18-2246

[57] Australian Bureau of Statistics (ABS). 4727.0.55.001 - Australian Aboriginal and Torres Strait Islander Health Survey: Psychological Distress 2012-2013. Available from: https://www.abs.gov.au/ ausstats/abs@.nsf/Lookup/9F3C9BDE98 B3C5F1CA257C2F00145721?opendocum ent [Accessed: 06 August 2019]

[58] Gould TJ. Addiction and cognition. Addiction Science and Clinical Practice. 2010;**5**(2):4-14. Available from: https:// www.ncbi.nlm.nih.gov/pmc/articles/ PMC3120118/

[59] Australian Government Australian Institute of Health and Welfare. Studies Resource Sheet no. 21 produced for the Closing the Gap Clearinghouse. Atkinson J. Trauma-Informed Services and Trauma-Specific Care for Indigenous Australian Children. 2013. pp. 4-9. Available from: https:// earlytraumagrief.anu.edu.au/files/ ctg-rs21.pdf

[60] Brown K. Customary Law: Sex with under-age promised wives. Alternative Law Journal. 2007;**32**(1):11-15. DOI: 10.1177/1037969X0703200105

[61] McGlade H. Justice as healing: Developing aboriginal justice models to address child sexual assault. Indigenous Law Bulletin 10. 2007;**7m**(1):10-13. Available from: http://www.austlii.edu. au/au/journals/IndigLawB/2007/59. html

[62] Sammut J. The Kinship Conundrum: The Impact of Aboriginal Self-Determination on Indigenous Child Protection. The Centre for Independent Studies. Policy Monograph 44. 2014. Available from: https://www.cis.org.au/app/ uploads/2015/07/pm144.pdf

[63] Kiraly M, James J, Humphreys C. 'It's a family responsibility': Family and cultural connection for aboriginal Children in kinship care. Children Australia. 2015;**40**(1):23-32. DOI: 10.1017/cha.2014.36

[64] Cunneen C, Tauri J. Violence and Indigenous Communities. In: DeKeseredy W, Rennison C, Hall-Sanchez A. editors. The Routledge International Handbook of Violence Studies, Routledge, New York. 2019. p. 350-361. Available from: https://ssrn. com/abstract=3308924

[65] Australian Government Royal Commission into Aboriginal Deaths in Custody. RCADIC. National Report. Canberra: Australian Government Publishing Service; 1991. Available from: http://www.austlii.edu.au/au/ other/IndigLRes/rciadic/

[66] Wootten H. Reflections on the 20th anniversary of the Royal Commission into aboriginal deaths in custody (Australia). Indigenous Law Bulletin, University of New South Wales, Indigenous Law Centre. 2011;**7**(27):3-8. Available from: http:// www.austlii.edu.au/au/journals/ AUIndigLawRw/2011/1.pdf

[67] New South Wales Ombudsman. How Are Taser Weapons Used by the NSW Police Force? Sydney: New South Wales Ombudsman; 2012. Available from: https://www.ombo.nsw.gov. au/\_\_data/assets/pdf\_file/0004/6970/ How-are-Taser-weapons-used-by-NSW-Police-Force-Special-report-to-Parliament-October-2012-.pdf

[68] Australian Government Department of Health, Implementation Plan for the National Aboriginal and Torres Strait Islander Health Plan 2013-2023. Australian Government, Canberra. 2015. pp. 10-34. Available from: https:// www1.health.gov.au/internet/main/ publishing.nsf/Content/AC51639D3C 8CD4ECCA257E8B00007AC5/\$File/ DOH\_ImplementationPlan\_v3.pdf

[69] Australian Health Practitioner Regulation Agency (AHPRA). Reconciliation Action Plan for the Australian Health Practitioner Regulation Agency. 2019. Available from: https://www.ahpra.gov.au/ documents/default.aspx?record=WD18 %2f25725&dbid=AP&chksum=zr4TMB VOgd2gtzNaG%2fya9w%3d%3d

[70] Lucas T. Crossing cultures: Land and encounters. The Lancet. 2015;**385**(9986):2452-2453. DOI: 10.1016/S0140-6736(15)61126-6

[71] Isobel S. Humanising mental health Care in Australia: A guide to trauma-informed approaches. Australasian Psychiatry. SAGE Publications. 2019;**27**(4):409-409. DOI: 10.1177/1039856219842642

[72] Nagel T, Hinton R, Griffin C. Yarning about indigenous mental health: Translation of a recovery paradigm to practice. Advances in Mental Health. Routledge. 2012;**10**(3):216-223. DOI: 10.5172/jamh.2012.10.3.216

[73] Lawson C, Woods D, McKenna T. Towards Indigenous Australian Knowing in Art Therapy in Australia. Leiden: Koninklijke Brill NV; 2019. DOI: 10.1163/9789004368262\_002

[74] Langton M. The right to the good life: Improving educational outcomes for aboriginal and Torres Strait islander Children. The Centre for Independent Studies CIS. Occasional Paper. 2013;**133**: 2-14. Available from: https://www.cis.org. au/app/uploads/2015/07/op133.pdf

**177**

**Chapter 11**

**Abstract**

suicidal behavior

**1. Introduction**

Psychosocial Autopsy of Mass

Suicides: Changing Patterns in

Incidents of mass suicides have been reported since ancient times wherein a large number of people killed themselves at the same time. These suicides occur for different reasons and goals. Historical perspective has revealed the presence of religious inspiration, death pacts and cults. Out of the various methods adopted for deciphering the psychological state of a person prior to committing suicide, plus a host of emotional, social, economic and cultural reasons, psychosocial autopsy is a promising one. It helps in investigating and analyzing the relevance of these interacting factors in self-inflicted deaths and provides an answer to the family members and friends of individuals who have died this way. A look into the literature reveals that there has been a change in pattern and motive of mass suicides across generations. An understanding of the decedent's personality, behavior patterns, motives, presence or absence of mental illness helps researchers in unearthing the suicidal risk factors that mitigate or aggravate suicidal behavior in masses. The present chapter discusses the change in pattern of mass suicide with the advent of comput-

ers and social media by citing some case studies from India and abroad.

**Keywords:** mass suicide, psychosocial autopsy, suicidal risk factors, suicidal pattern,

India recently witnessed two unnerving suicide events. In 2018, 10 family members of the Chundawat family from *Burari* were found hanged, while the oldest family member, the grandmother, was strangled. The *Burari* deaths are infamously known as the "*Burari* case" or "*Burari Kand*." In another wave of suicides, in 2019, over 20 students killed themselves in a span of 1 week since Telangana Intermediate Examination results were announced. These two events, even though isolated in space and time, can be categorized under the phenomenon of mass or cluster suicides. While the major underlying cause of Telangana deaths was identified as failure of students in examination, it is the Burari case that perplexed one and all. This case was beyond the scrutiny of logic as it could not be explained by the usual causes of suicide in India, such as health concerns (mental and physical), bankruptcy and indebtedness [1]. Thus, Burari and Telangana point towards two different motives for suicide. With the help of these two examples, the authors wish

to highlight the complexity and diversity prevalent in suicidal behavior.

Contemporary Times

*Nishi Misra, Harshita Jha and Komal Tiwari*

#### **Chapter 11**

*Neurological and Mental Disorders*

[68] Australian Government Department of Health, Implementation Plan for the National Aboriginal and Torres Strait Islander Health Plan 2013-2023. Australian Government, Canberra. 2015. pp. 10-34. Available from: https:// www1.health.gov.au/internet/main/ publishing.nsf/Content/AC51639D3C 8CD4ECCA257E8B00007AC5/\$File/ DOH\_ImplementationPlan\_v3.pdf

[69] Australian Health Practitioner Regulation Agency (AHPRA). Reconciliation Action Plan for the Australian Health Practitioner Regulation Agency. 2019. Available from: https://www.ahpra.gov.au/ documents/default.aspx?record=WD18 %2f25725&dbid=AP&chksum=zr4TMB VOgd2gtzNaG%2fya9w%3d%3d

[70] Lucas T. Crossing cultures: Land and encounters. The Lancet. 2015;**385**(9986):2452-2453. DOI: 10.1016/S0140-6736(15)61126-6

[71] Isobel S. Humanising mental health Care in Australia: A guide to trauma-informed approaches. Australasian Psychiatry. SAGE

[72] Nagel T, Hinton R, Griffin C.

10.1177/1039856219842642

10.5172/jamh.2012.10.3.216

Publications. 2019;**27**(4):409-409. DOI:

Yarning about indigenous mental health: Translation of a recovery paradigm to practice. Advances in Mental Health. Routledge. 2012;**10**(3):216-223. DOI:

[73] Lawson C, Woods D, McKenna T. Towards Indigenous Australian Knowing in Art Therapy in Australia. Leiden: Koninklijke Brill NV; 2019. DOI: 10.1163/9789004368262\_002

[74] Langton M. The right to the good life: Improving educational outcomes for aboriginal and Torres Strait islander Children. The Centre for Independent Studies CIS. Occasional Paper. 2013;**133**: 2-14. Available from: https://www.cis.org. au/app/uploads/2015/07/op133.pdf

**176**

## Psychosocial Autopsy of Mass Suicides: Changing Patterns in Contemporary Times

*Nishi Misra, Harshita Jha and Komal Tiwari*

#### **Abstract**

Incidents of mass suicides have been reported since ancient times wherein a large number of people killed themselves at the same time. These suicides occur for different reasons and goals. Historical perspective has revealed the presence of religious inspiration, death pacts and cults. Out of the various methods adopted for deciphering the psychological state of a person prior to committing suicide, plus a host of emotional, social, economic and cultural reasons, psychosocial autopsy is a promising one. It helps in investigating and analyzing the relevance of these interacting factors in self-inflicted deaths and provides an answer to the family members and friends of individuals who have died this way. A look into the literature reveals that there has been a change in pattern and motive of mass suicides across generations. An understanding of the decedent's personality, behavior patterns, motives, presence or absence of mental illness helps researchers in unearthing the suicidal risk factors that mitigate or aggravate suicidal behavior in masses. The present chapter discusses the change in pattern of mass suicide with the advent of computers and social media by citing some case studies from India and abroad.

**Keywords:** mass suicide, psychosocial autopsy, suicidal risk factors, suicidal pattern, suicidal behavior

#### **1. Introduction**

India recently witnessed two unnerving suicide events. In 2018, 10 family members of the Chundawat family from *Burari* were found hanged, while the oldest family member, the grandmother, was strangled. The *Burari* deaths are infamously known as the "*Burari* case" or "*Burari Kand*." In another wave of suicides, in 2019, over 20 students killed themselves in a span of 1 week since Telangana Intermediate Examination results were announced. These two events, even though isolated in space and time, can be categorized under the phenomenon of mass or cluster suicides. While the major underlying cause of Telangana deaths was identified as failure of students in examination, it is the Burari case that perplexed one and all. This case was beyond the scrutiny of logic as it could not be explained by the usual causes of suicide in India, such as health concerns (mental and physical), bankruptcy and indebtedness [1]. Thus, Burari and Telangana point towards two different motives for suicide. With the help of these two examples, the authors wish to highlight the complexity and diversity prevalent in suicidal behavior.

The phenomenon of suicide can be viewed as a spectrum and the only way to arrive at any meaningful suicide prevention strategy is to first understand this psycho-social phenomenon in its different expressions. At a time when India is grappling with issues of mental health, this chapter aims to draw attention to the emerging trend of clustering and contagion in suicidal behavior, its nature as well as its manifestation, as witnessed in the contemporary Indian social cultural set-up.

#### **1.1 From mass to cluster: Emerging trends in suicidal behavior in India**

Recently, the rate of cluster suicides in India has been growing rapidly since the last decade. It is a matter of deep concern as it became a massive social problem and thus, effective interventions and solution for suicide prevention need to be developed at the earliest.

There is a shift in the predominance of the number of suicides from the elderly to the younger people all over the world. India is labeled as "Suicide Capital of South-East Asia' as it has recorded the highest number of suicides in South-East Asia in 2012, according to a WHO report [2] also in 2016 the number of suicides in India had increased to 230,314 and suicide was the most common cause of death in both the age groups of 15–29 years and 15–39 years. India has a major contribution to global suicide deaths as it increased from 25·3% in 1990 to 36·6% in 2016 among women, and from 18·7 to 24·3% among men.

There are several different types of mass suicide events that can occur, each for a different reason and for different goals. Form historical perspective the most infamous events of mass suicides are those that are related to religious groups or cults.

#### **1.2 Suicide in ancient India**

An understanding of the historical trends with respect to suicide in India takes us back to the ancient scriptures that emerged in the Indian society. After having reviewed different Indian scriptures such as the Upanishads, the Bhagvad Gita and the Brahma Sutras it was concluded that suicide is not either explicitly condemned or glorified nor is it seen as a crime in these ancient Indian texts [3]. Although suicide does find mention in the great epics of Ramayana and Mahabharata, it appears that whether such behavior was approved or disapproved depended on the intent of killing oneself, which was perhaps more important than the behavior itself. Thus, if suicide was undertaken due to selfish reasons, it was likely to be disapproved, but if it was undertaken for heroic or self-sacrificial reasons, it was seen in a more positive light. Within the Indian context, it is also debatable whether taking one's life to attain self-realization or enlightenment should be considered "suicide" or not. In such instances, a more suitable term seems to be "leaving one's body" rather than "killing oneself." Some Indian philosophical systems have emphasized on the existence of soul or atman, which is eternal and imperishable in nature, therefore death is then considered an end to the body or gross physical matter and not the soul.

In some religions such as Jainism there is provision known as "sallekhana" or "sanyasa-marana." It can be defined as the religious practice of voluntarily fasting to death by gradually reducing the intake of food. It is linked to the attainment of "moksha," the liberation from the cycle of life and death [4]. Sallekhana is sanctified morally and ethically by the Jain community, thus it is not considered an act of suicide. These observations point towards the increasing necessity of a culturally based understanding of suicide. Hinduism condemns suicide, but in specific instances accepts it as a meritorious act of self-sacrifice. It is cited in the Manusmriti that libations of water, which are usually offered to the departed souls, should not be offered to those who commit suicide.

**179**

*Psychosocial Autopsy of Mass Suicides: Changing Patterns in Contemporary Times*

In India's past, there have also been widespread instances of "Sati" and "Jauhar" or "Juhar." These practices were considered courageous and an act to save honor. "Jauhar" or "Juhar" was practiced by Rajput women and involved mass selfimmolation, primarily to avoid capture, enslavement and rape by any foreign invader. While, "Jauhar" happens to be an example of mass suicide in India, when it comes to contemporary times the picture is different. There are growing instances of cluster suicide in India. The Burari deaths and the Telangana student suicides are

History is replete with unforgettable cases of mass suicides. Mass suicide of Jonestown is perhaps one such haunting example that springs to memory. It is popularly known as "People's temple mass suicide." In the 1970s, Jim Jones, a selfstyled prophet established a "socialist community" in Guyana named Jonestown. Jones was popular for his notorious image and was under the scanner for financial fraud and child abuse. Establishing an isolated community in a remote corner was perhaps one of the best ways to sustain his delusions and escape arrest. However, even after he moved to Guyana investigations against him continued. Moreover, his followers who moved with him soon discovered that the utopian world promised to them i.e. "an agricultural commune rich with food, where there were no mosquitoes or snakes and where temperatures hovered around a perfect 72° every single day" was a big lie. Instead, they were starving, living in hot and humid climate, full of mosquitoes and snakes. Naturally, his followers began looking for ways to flee. It has been reported that distressed by his followers' attempts to run away; he ordered them to consume a cyanide-laced potion, which eventually resulted in the death of over 900 people. Later analysis has revealed it as more appropriately a case of mass homicide rather than suicide, as his followers were surrounded by Jones's armed guards, thus they were left with no other option than to die. Jonestown massacre is a classic example of how one man's delusion can be conta-

Similar cases of mass suicide have been reported in different areas of the world,

including the Heaven's Gate Mass Suicide in California, where 39 people of the eccentric Heaven's Gate cult committed suicide. They were all dressed identically, were lying on their bunk beds with plastic bags around their heads. They were misled by their Marshall that a UFO was following the comet Hale Bopp and leaving the human world was the only way to evacuate this earth and reach a better cosmic

In Uganda, the Movement of the Restoration of ten Commandments of God (MRTCG) was a Catholic group that was convinced that the world would come to an end when the millennium calendar began. On 17 March 2000, they resorted to

In all of these cases, it can be observed that the self-proclaimed cult leaders exploited the vulnerabilities of people to meet their own ends. The fabled utopian land is often based on religious foundation. These cases are also testimony to the failure of reason. People when promised of "ideal land" and "perfect future" are willing to stake everything that they have; blindly following the one "messiah" that

Mass suicide can be defined as the simultaneous suicide of all the members of a social group [6]. Mancinelli has subdivided mass suicides into two categories:

*DOI: http://dx.doi.org/10.5772/intechopen.89439*

examples of this growing trend.

**1.3 Mass suicides in the world**

gious to a mass of people.

self-immolation and poisoning.

promises them a better life or rather a better death.

**1.4 Mass suicides and cluster suicides**

world [5].

#### *Psychosocial Autopsy of Mass Suicides: Changing Patterns in Contemporary Times DOI: http://dx.doi.org/10.5772/intechopen.89439*

In India's past, there have also been widespread instances of "Sati" and "Jauhar" or "Juhar." These practices were considered courageous and an act to save honor. "Jauhar" or "Juhar" was practiced by Rajput women and involved mass selfimmolation, primarily to avoid capture, enslavement and rape by any foreign invader. While, "Jauhar" happens to be an example of mass suicide in India, when it comes to contemporary times the picture is different. There are growing instances of cluster suicide in India. The Burari deaths and the Telangana student suicides are examples of this growing trend.

#### **1.3 Mass suicides in the world**

*Neurological and Mental Disorders*

oped at the earliest.

women, and from 18·7 to 24·3% among men.

**1.2 Suicide in ancient India**

The phenomenon of suicide can be viewed as a spectrum and the only way to arrive at any meaningful suicide prevention strategy is to first understand this psycho-social phenomenon in its different expressions. At a time when India is grappling with issues of mental health, this chapter aims to draw attention to the emerging trend of clustering and contagion in suicidal behavior, its nature as well as its manifestation, as witnessed in the contemporary Indian social cultural set-up.

Recently, the rate of cluster suicides in India has been growing rapidly since the last decade. It is a matter of deep concern as it became a massive social problem and thus, effective interventions and solution for suicide prevention need to be devel-

There is a shift in the predominance of the number of suicides from the elderly

There are several different types of mass suicide events that can occur, each for a different reason and for different goals. Form historical perspective the most infamous events of mass suicides are those that are related to religious groups or cults.

An understanding of the historical trends with respect to suicide in India takes us back to the ancient scriptures that emerged in the Indian society. After having reviewed different Indian scriptures such as the Upanishads, the Bhagvad Gita and the Brahma Sutras it was concluded that suicide is not either explicitly condemned or glorified nor is it seen as a crime in these ancient Indian texts [3]. Although suicide does find mention in the great epics of Ramayana and Mahabharata, it appears that whether such behavior was approved or disapproved depended on the intent of killing oneself, which was perhaps more important than the behavior itself. Thus, if suicide was undertaken due to selfish reasons, it was likely to be disapproved, but if it was undertaken for heroic or self-sacrificial reasons, it was seen in a more positive light. Within the Indian context, it is also debatable whether taking one's life to attain self-realization or enlightenment should be considered "suicide" or not. In such instances, a more suitable term seems to be "leaving one's body" rather than "killing oneself." Some Indian philosophical systems have emphasized on the existence of soul or atman, which is eternal and imperishable in nature, therefore death is then considered an end to the body or gross physical matter and not the soul. In some religions such as Jainism there is provision known as "sallekhana" or "sanyasa-marana." It can be defined as the religious practice of voluntarily fasting to death by gradually reducing the intake of food. It is linked to the attainment of "moksha," the liberation from the cycle of life and death [4]. Sallekhana is sanctified morally and ethically by the Jain community, thus it is not considered an act of suicide. These observations point towards the increasing necessity of a culturally based understanding of suicide. Hinduism condemns suicide, but in specific instances accepts it as a meritorious act of self-sacrifice. It is cited in the Manusmriti that libations of water, which are usually offered to the departed souls, should not

to the younger people all over the world. India is labeled as "Suicide Capital of South-East Asia' as it has recorded the highest number of suicides in South-East Asia in 2012, according to a WHO report [2] also in 2016 the number of suicides in India had increased to 230,314 and suicide was the most common cause of death in both the age groups of 15–29 years and 15–39 years. India has a major contribution to global suicide deaths as it increased from 25·3% in 1990 to 36·6% in 2016 among

**1.1 From mass to cluster: Emerging trends in suicidal behavior in India**

**178**

be offered to those who commit suicide.

History is replete with unforgettable cases of mass suicides. Mass suicide of Jonestown is perhaps one such haunting example that springs to memory. It is popularly known as "People's temple mass suicide." In the 1970s, Jim Jones, a selfstyled prophet established a "socialist community" in Guyana named Jonestown. Jones was popular for his notorious image and was under the scanner for financial fraud and child abuse. Establishing an isolated community in a remote corner was perhaps one of the best ways to sustain his delusions and escape arrest. However, even after he moved to Guyana investigations against him continued. Moreover, his followers who moved with him soon discovered that the utopian world promised to them i.e. "an agricultural commune rich with food, where there were no mosquitoes or snakes and where temperatures hovered around a perfect 72° every single day" was a big lie. Instead, they were starving, living in hot and humid climate, full of mosquitoes and snakes. Naturally, his followers began looking for ways to flee. It has been reported that distressed by his followers' attempts to run away; he ordered them to consume a cyanide-laced potion, which eventually resulted in the death of over 900 people. Later analysis has revealed it as more appropriately a case of mass homicide rather than suicide, as his followers were surrounded by Jones's armed guards, thus they were left with no other option than to die. Jonestown massacre is a classic example of how one man's delusion can be contagious to a mass of people.

Similar cases of mass suicide have been reported in different areas of the world, including the Heaven's Gate Mass Suicide in California, where 39 people of the eccentric Heaven's Gate cult committed suicide. They were all dressed identically, were lying on their bunk beds with plastic bags around their heads. They were misled by their Marshall that a UFO was following the comet Hale Bopp and leaving the human world was the only way to evacuate this earth and reach a better cosmic world [5].

In Uganda, the Movement of the Restoration of ten Commandments of God (MRTCG) was a Catholic group that was convinced that the world would come to an end when the millennium calendar began. On 17 March 2000, they resorted to self-immolation and poisoning.

In all of these cases, it can be observed that the self-proclaimed cult leaders exploited the vulnerabilities of people to meet their own ends. The fabled utopian land is often based on religious foundation. These cases are also testimony to the failure of reason. People when promised of "ideal land" and "perfect future" are willing to stake everything that they have; blindly following the one "messiah" that promises them a better life or rather a better death.

#### **1.4 Mass suicides and cluster suicides**

Mass suicide can be defined as the simultaneous suicide of all the members of a social group [6]. Mancinelli has subdivided mass suicides into two categories:

Firstly, (a) hetero-induced, in which a particular population has reacted to oppression, it is typical of defeated and colonized populations forced to escape from reality that does not acknowledge their human dignity, thus people may choose to kill themselves rather than submit to their oppressors. These deaths are often looked upon as heroic and may find a place among cultural myths and legends. Secondly, (b) self-induced, in which the motivation is related to a distorted evaluation of reality, without there being either an intolerable situation or a real risk of death. The question perhaps is whether these categorizations are enough to encompass the range of suicidal behavior that occurs in the present Indian society.

Suicide cluster has been defined as "a series of three or more closely grouped deaths within three months that can be linked by space or social relationships. In the absence of transparent social connectedness, evidence of space and time linkages are required to define a candidate cluster. In the presence of a strong demonstrated social connection, only temporal significance is required" [7]. Another type of suicide cluster referred to as "mass clusters", has been commonly defined as "a temporary increase in the total frequency of suicides within an entire population relative to the period immediately before and after the cluster, with no spatial clustering" [8].

Cluster suicide can be differentiated from mass suicide as a "pocket" phenomenon. It is defined by its contextual factors. Generally, studying clusters becomes more difficult than studying masses, as both temporality and spatiality of the event takes prime importance in its understanding. Again the Burari deaths and Telangana student suicides prove to be examples of the importance of local factors that played a role in these acts.

#### **1.5 Types of suicide cluster**

There are two main types of suicide clusters: **point** and **mass** [9–11].


A new concept has been introduced recently that is **Echo cluster**, the occurrence of subsequent, indigenous suicide which takes place in the same location after an initial suicide [7, 13].

Most attention has focused until recently on a greater than expected number of suicides in specific locations and time periods ("point clusters"), such as the cluster of suicides that occurred in Burari in Delhi where 11 members of a family committed suicide cumulatively.

It is observed that the mechanisms underlying suicide clusters are unclear. It has been proposed that point clusters may result from a process of "contagion," whereby one person's suicidal thoughts and behaviors are transmitted from one victim to another through social or interpersonal connections [10, 12].

**181**

*Psychosocial Autopsy of Mass Suicides: Changing Patterns in Contemporary Times*

In India there are several categories of suicide cluster which are related with their area of profession. Some of them are students' suicide, family suicide and farmers'

Student suicide: Now a day's education is becoming society's most critical responsibility as it is more related with social status. Students have to face many challenges that affect their life directly or indirectly like academic stress caused by the very system of education, acquisition of grades, coping up with peer pressure & parental pressure and the emotional disturbances to secure good marks and position. Poor scholastic performance, rising expectations from parents, getting involved in relationships these are the reasons which prompt a

Kota in State of Rajasthan in India is well known for its coaching of students for various admission exams after 12th standard. It has become the suicide city as the number of students committing suicide has increased drastically. By the end of the year 2018 three medical/ IIT students committed suicide within four days which brought unsettling case of students suicides. Total 19 students committed

A recent example of student suicide cluster was in Indian state of Telangana where more than 20 students killed themselves within a week after declaration of intermediate examination results. Due to the occurrence of these incidents, India's education system is criticized as a poor one in which students are under heavy pressure not just to pass examinations but to exceed expectations at all costs. The instrumental value of education in India is its potential in generating socio-economic and

Recently in July, 2019 three members of a family ended up their life by consuming some toxins in Punjab. According to police records, some sort of family tension within the household led to this extreme step. Again after few days three of family

Farmer Suicide: Two thirds of India's population are dependent on agriculture for their livelihood. The earth is most generous employer in this country of a billion [14] 'It is the agricultural sector that the battle for long term economic development will be won or lost. For over a decade, famer suicides have been a serious public policy concern. More recently, this has also led to shrill outcry from the media and much politicking. The government response to the crisis of farmer suicide has

This is a particular concern for country. It is observed that huge debts, inadequate income from agriculture to repay the borrowed money, the absence of any help from outer sources, are the main cause of farmer's suicide, making them choose to end their lives. Factors contributing to the high rate of suicide in this vulnerable population include economic adversity, exclusive dependence on rainfall for agriculture, and possibly monetary compensation to the family following suicide.

mostly been simplistic and in some cases perhaps aggravating [1].

cultural capital through a promise of decent job opportunities in the future. Family suicide: takes place when a whole family is unanimously agreeing to take the critical step to commit suicide together. There has been a vast increase in the family suicide cases in last 2–3 years. This phenomenon came in light after the death of 11 members of family in the mysterious Burari case'. After few days of Burari case, seven members of family committed suicide in July 2018, According to police, the family was reeling under financial hardships. In March, 2013 the same thing happened in Gangapur District of Rajasthan where eight members of a family consumed poison to committed suicide together. The family was highly religious.

*DOI: http://dx.doi.org/10.5772/intechopen.89439*

**1.6 Categories of suicide**

student to commit suicide.

They also made a video before suicide.

members were found hanging on IIT campus.

suicide in 2018.

suicide.

#### **1.6 Categories of suicide**

*Neurological and Mental Disorders*

spatial clustering" [8].

that played a role in these acts.

**1.5 Types of suicide cluster**

surrounding area [9–12].

attention [10, 12].

initial suicide [7, 13].

ted suicide cumulatively.

Firstly, (a) hetero-induced, in which a particular population has reacted to oppression, it is typical of defeated and colonized populations forced to escape from reality that does not acknowledge their human dignity, thus people may choose to kill themselves rather than submit to their oppressors. These deaths are often looked upon as heroic and may find a place among cultural myths and legends. Secondly, (b) self-induced, in which the motivation is related to a distorted evaluation of reality, without there being either an intolerable situation or a real risk of death. The question perhaps is whether these categorizations are enough to encompass the

Suicide cluster has been defined as "a series of three or more closely grouped deaths within three months that can be linked by space or social relationships. In the absence of transparent social connectedness, evidence of space and time linkages are required to define a candidate cluster. In the presence of a strong demonstrated social connection, only temporal significance is required" [7]. Another type of suicide cluster referred to as "mass clusters", has been commonly defined as "a temporary increase in the total frequency of suicides within an entire population relative to the period immediately before and after the cluster, with no

Cluster suicide can be differentiated from mass suicide as a "pocket" phenomenon. It is defined by its contextual factors. Generally, studying clusters becomes more difficult than studying masses, as both temporality and spatiality of the event takes prime importance in its understanding. Again the Burari deaths and Telangana student suicides prove to be examples of the importance of local factors

There are two main types of suicide clusters: **point** and **mass** [9–11].

1.**Point cluster**- Point clusters are time space clustering close in both location and time, that occurs in small communities, and involve a temporary increase in frequency of suicides above a baseline rate observed in the community and

2.**Mass clusters**- occur when a large amount of people kills themselves at the same time. It involves a temporary increase in suicides across a whole population. The difference between point and mass is that it is close in time but not necessarily location. Mass clusters have been documented following suicides of high-profile celebrities or others who receive considerable media

A new concept has been introduced recently that is **Echo cluster**, the occurrence of subsequent, indigenous suicide which takes place in the same location after an

Most attention has focused until recently on a greater than expected number of suicides in specific locations and time periods ("point clusters"), such as the cluster of suicides that occurred in Burari in Delhi where 11 members of a family commit-

It is observed that the mechanisms underlying suicide clusters are unclear. It has been proposed that point clusters may result from a process of "contagion," whereby one person's suicidal thoughts and behaviors are transmitted from one victim to

another through social or interpersonal connections [10, 12].

range of suicidal behavior that occurs in the present Indian society.

**180**

In India there are several categories of suicide cluster which are related with their area of profession. Some of them are students' suicide, family suicide and farmers' suicide.

Student suicide: Now a day's education is becoming society's most critical responsibility as it is more related with social status. Students have to face many challenges that affect their life directly or indirectly like academic stress caused by the very system of education, acquisition of grades, coping up with peer pressure & parental pressure and the emotional disturbances to secure good marks and position. Poor scholastic performance, rising expectations from parents, getting involved in relationships these are the reasons which prompt a student to commit suicide.

Kota in State of Rajasthan in India is well known for its coaching of students for various admission exams after 12th standard. It has become the suicide city as the number of students committing suicide has increased drastically. By the end of the year 2018 three medical/ IIT students committed suicide within four days which brought unsettling case of students suicides. Total 19 students committed suicide in 2018.

A recent example of student suicide cluster was in Indian state of Telangana where more than 20 students killed themselves within a week after declaration of intermediate examination results. Due to the occurrence of these incidents, India's education system is criticized as a poor one in which students are under heavy pressure not just to pass examinations but to exceed expectations at all costs. The instrumental value of education in India is its potential in generating socio-economic and cultural capital through a promise of decent job opportunities in the future.

Family suicide: takes place when a whole family is unanimously agreeing to take the critical step to commit suicide together. There has been a vast increase in the family suicide cases in last 2–3 years. This phenomenon came in light after the death of 11 members of family in the mysterious Burari case'. After few days of Burari case, seven members of family committed suicide in July 2018, According to police, the family was reeling under financial hardships. In March, 2013 the same thing happened in Gangapur District of Rajasthan where eight members of a family consumed poison to committed suicide together. The family was highly religious. They also made a video before suicide.

Recently in July, 2019 three members of a family ended up their life by consuming some toxins in Punjab. According to police records, some sort of family tension within the household led to this extreme step. Again after few days three of family members were found hanging on IIT campus.

Farmer Suicide: Two thirds of India's population are dependent on agriculture for their livelihood. The earth is most generous employer in this country of a billion [14] 'It is the agricultural sector that the battle for long term economic development will be won or lost. For over a decade, famer suicides have been a serious public policy concern. More recently, this has also led to shrill outcry from the media and much politicking. The government response to the crisis of farmer suicide has mostly been simplistic and in some cases perhaps aggravating [1].

This is a particular concern for country. It is observed that huge debts, inadequate income from agriculture to repay the borrowed money, the absence of any help from outer sources, are the main cause of farmer's suicide, making them choose to end their lives. Factors contributing to the high rate of suicide in this vulnerable population include economic adversity, exclusive dependence on rainfall for agriculture, and possibly monetary compensation to the family following suicide.

#### **1.7 Mechanisms involved in mass suicides**

#### *1.7.1 Contagion of suicidal behavior*

Contagion has been defined as an underlying assumption that "suicidal behavior may facilitate the occurrence of subsequent suicidal behavior, either directly (via contact or friendship with the index suicide) or indirectly (via the media) [9].

#### *1.7.2 Imitation*

It is necessary to distinguish various types of individual suicide that might be imitated. One type of suicide relates to some symbolic or group activity which creates group pressure(s) that cause an individual to kill oneself (a form of altruistic suicide). A second type that might trigger imitative suicide involves individual's prominence in specialized occupations, e.g., a well-known artist or businessperson. It is possible that such suicides might cause suicide among individuals with similar occupational backgrounds who have experienced crisis or failure. However, this imitation is only likely to occur among a small subgroup of the population. A third category that might trigger imitative suicide is the suicide of national celebrities, i.e., individuals who are well known and recognized by name and pictorial image by the larger American public. These individuals have usually achieved prominence in an occupation subject to significant public exposure, but some social actors may become celebrities through their social connections with other prominent celebrities [15].

#### *1.7.3 Suggestibility*

Philips [16] examined U.S. and U.K. suicide rates from 1947 to 1968 and reported that suicides increased after highly publicized deaths by suicide. He proposed that news reports of suicides influenced suicide risk by means of "suggestion". He dubbed this the "Werther effect." Projective identification has been regarded as a psychoanalytical concept, which refers to feelings of empathy towards suicide. There is a blurring of self and suicide followed by a re-internalization of projection, leading to suicidal behavior.

In Priming [17], activation of one thought may trigger related pre-programmed thoughts. Media images stimulate related thoughts in the minds of audience members.

Social Integration and regulation: Where there is a lack of social ties in the community, social integration is low, leading to individualism and egoistic suicide and where interests of groups dominate those of individuals, altruistic suicides result [18].

Homophily or assortative relating [10]: The tendency of people to preferentially associate with one another and associative susceptibility, [19] where a stressful event occurring in a local community will affect several vulnerable individuals independently of each other.

Certain religious beliefs may leave people feeling guilty for things they have done and may lead them to think that they cannot be forgiven. Some believe that sacrificing themselves will earn them a reward (like going to heaven) or in countries like Japan, shame or dishonor may be a reason, like hara-kiri or seppuku.

#### **1.8 Multidimensional nature of suicide**

The multidimensional nature of suicides is reflected in the array of motives and risk factors associated with it. It has been referred to as "multidimensional,

**183**

*Psychosocial Autopsy of Mass Suicides: Changing Patterns in Contemporary Times*

multifactorial malaise" [20]. Previous researches have mostly studied the psychosocial risk factors associated with suicides. It appears that both individual factors as well as situational factors intermingle in a complex manner to determine suicidal behavior. The demographics of suicide in India [21] reveals factors such as Age, Gender, Marital status, Education, Family structure, Urban vs. rural residence, Occupation and Precipitating event, play a role determining suicidal behavior. As per the National Crime Records Bureau 2009 data [22], the top 10 causes or correlates of suicide in 2009 were identified as family problems (23.7%), illness (21%) [including insanity/mental illness (6.7%)], unemployment (1.9%), love affairs (2.9%), drug abuse/addiction (2.3%), failure in examination (1.6%), bankruptcy or sudden change in economic status (2.5%), poverty (2.3%), and dowry dispute (2.3%). In addition, the high rates of suicide among persons with mental illness and drug abuse/addiction are of much concern. Substance abuse, problems with parents-in-law and spouses and mental illness are the risk factors that are increas-

There are vulnerable individuals with negative self-esteem, socially isolated, who tend to internalize feelings and conflicts and are over-dependent on their families. Drug and alcohol abuse, employment problems, a history of self-harm

Mass suicides are seen as suicide pacts in couples or families rather than as part of religious cults as in western societies. Suicide pacts almost always involve people well known to each other, mostly spouses, most of them childless. However, there is an emerging trend for cyber-based internet-facilitated suicide pacts which increasingly involve two or more strangers who meet on the internet and share similar world views. Such cases have been reported in the press, but have not been studied

Those who are especially susceptible to suicide contagion are adolescents with suicidal thoughts and people with depression, bipolar disorder, anxiety, schizophre-

Exposure to previous trauma makes a person susceptible to develop PTSD, especially in cases of physical and emotional proximity to the event and victim. Rumination followed by intrusive thinking are additional causes. In such instances long term emotional support is needed, which if found missing, has its adverse consequences. The mass trauma caused by mass suicide is likely to affect the mental health of individuals. Depression has been regarded as a key risk factor for suicide. Substance abuse, chronic pain, a family history of suicide, a prior suicide attempt

The media sometimes gives intense publicity to "suicide clusters" - a series of suicides that occur mainly among young people in a small area within a short period of time. These have a contagious effect especially when they have been glamorized, provoking imitation or "copycat suicides". This phenomenon has been observed in India on many occasions, especially after the death of a celebrity, most often a movie star or a politician. The wide exposure given to these suicides by the media has led to suicides in a similar manner. Copying methods shown in movies are also not uncommon. This is a serious problem especially in India where film stars enjoy an iconic status and wield enormous influence especially over the young who often

and impulsiveness plays a major role in adolescent suicides.

*DOI: http://dx.doi.org/10.5772/intechopen.89439*

ingly gaining momentum in the Indian society [23].

have been quoted as possible causes [24].

in a scientific manner [20].

**1.10 The dual role of media**

look up to them as role models.

nia and PTSD.

**1.9 Role of mental illness in suicides**

#### *Psychosocial Autopsy of Mass Suicides: Changing Patterns in Contemporary Times DOI: http://dx.doi.org/10.5772/intechopen.89439*

multifactorial malaise" [20]. Previous researches have mostly studied the psychosocial risk factors associated with suicides. It appears that both individual factors as well as situational factors intermingle in a complex manner to determine suicidal behavior. The demographics of suicide in India [21] reveals factors such as Age, Gender, Marital status, Education, Family structure, Urban vs. rural residence, Occupation and Precipitating event, play a role determining suicidal behavior. As per the National Crime Records Bureau 2009 data [22], the top 10 causes or correlates of suicide in 2009 were identified as family problems (23.7%), illness (21%) [including insanity/mental illness (6.7%)], unemployment (1.9%), love affairs (2.9%), drug abuse/addiction (2.3%), failure in examination (1.6%), bankruptcy or sudden change in economic status (2.5%), poverty (2.3%), and dowry dispute (2.3%). In addition, the high rates of suicide among persons with mental illness and drug abuse/addiction are of much concern. Substance abuse, problems with parents-in-law and spouses and mental illness are the risk factors that are increasingly gaining momentum in the Indian society [23].

There are vulnerable individuals with negative self-esteem, socially isolated, who tend to internalize feelings and conflicts and are over-dependent on their families. Drug and alcohol abuse, employment problems, a history of self-harm have been quoted as possible causes [24].

Mass suicides are seen as suicide pacts in couples or families rather than as part of religious cults as in western societies. Suicide pacts almost always involve people well known to each other, mostly spouses, most of them childless. However, there is an emerging trend for cyber-based internet-facilitated suicide pacts which increasingly involve two or more strangers who meet on the internet and share similar world views. Such cases have been reported in the press, but have not been studied in a scientific manner [20].

#### **1.9 Role of mental illness in suicides**

Those who are especially susceptible to suicide contagion are adolescents with suicidal thoughts and people with depression, bipolar disorder, anxiety, schizophrenia and PTSD.

Exposure to previous trauma makes a person susceptible to develop PTSD, especially in cases of physical and emotional proximity to the event and victim. Rumination followed by intrusive thinking are additional causes. In such instances long term emotional support is needed, which if found missing, has its adverse consequences. The mass trauma caused by mass suicide is likely to affect the mental health of individuals. Depression has been regarded as a key risk factor for suicide. Substance abuse, chronic pain, a family history of suicide, a prior suicide attempt and impulsiveness plays a major role in adolescent suicides.

#### **1.10 The dual role of media**

The media sometimes gives intense publicity to "suicide clusters" - a series of suicides that occur mainly among young people in a small area within a short period of time. These have a contagious effect especially when they have been glamorized, provoking imitation or "copycat suicides". This phenomenon has been observed in India on many occasions, especially after the death of a celebrity, most often a movie star or a politician. The wide exposure given to these suicides by the media has led to suicides in a similar manner. Copying methods shown in movies are also not uncommon. This is a serious problem especially in India where film stars enjoy an iconic status and wield enormous influence especially over the young who often look up to them as role models.

*Neurological and Mental Disorders*

*1.7.1 Contagion of suicidal behavior*

*1.7.2 Imitation*

prominent celebrities [15].

leading to suicidal behavior.

independently of each other.

**1.8 Multidimensional nature of suicide**

*1.7.3 Suggestibility*

members.

**1.7 Mechanisms involved in mass suicides**

Contagion has been defined as an underlying assumption that "suicidal behavior may facilitate the occurrence of subsequent suicidal behavior, either directly (via contact or friendship with the index suicide) or indirectly (via the media) [9].

It is necessary to distinguish various types of individual suicide that might be imitated. One type of suicide relates to some symbolic or group activity which creates group pressure(s) that cause an individual to kill oneself (a form of altruistic suicide). A second type that might trigger imitative suicide involves individual's prominence in specialized occupations, e.g., a well-known artist or businessperson. It is possible that such suicides might cause suicide among individuals with similar occupational backgrounds who have experienced crisis or failure. However, this imitation is only likely to occur among a small subgroup of the population. A third category that might trigger imitative suicide is the suicide of national celebrities, i.e., individuals who are well known and recognized by name and pictorial image by the larger American public. These individuals have usually achieved prominence in an occupation subject to significant public exposure, but some social actors may become celebrities through their social connections with other

Philips [16] examined U.S. and U.K. suicide rates from 1947 to 1968 and reported

In Priming [17], activation of one thought may trigger related pre-programmed

Social Integration and regulation: Where there is a lack of social ties in the community, social integration is low, leading to individualism and egoistic suicide and where interests of groups dominate those of individuals, altruistic suicides result [18]. Homophily or assortative relating [10]: The tendency of people to preferentially

associate with one another and associative susceptibility, [19] where a stressful event occurring in a local community will affect several vulnerable individuals

like Japan, shame or dishonor may be a reason, like hara-kiri or seppuku.

Certain religious beliefs may leave people feeling guilty for things they have done and may lead them to think that they cannot be forgiven. Some believe that sacrificing themselves will earn them a reward (like going to heaven) or in countries

The multidimensional nature of suicides is reflected in the array of motives and risk factors associated with it. It has been referred to as "multidimensional,

that suicides increased after highly publicized deaths by suicide. He proposed that news reports of suicides influenced suicide risk by means of "suggestion". He dubbed this the "Werther effect." Projective identification has been regarded as a psychoanalytical concept, which refers to feelings of empathy towards suicide. There is a blurring of self and suicide followed by a re-internalization of projection,

thoughts. Media images stimulate related thoughts in the minds of audience

**182**

#### **2. Methods of suicide study**

Two prominent methods are psychological and psychosocial autopsy.

In depth study of the history of suicide prior to the suicidal act is known as psychological autopsy [25]. Psychological autopsy is a method created by Shneidman [26]. It has become widespread in the last 2–3 decades.

Psychological autopsy is a depth study of a person's mental state by analyzing medical records, interviewing friends and family and conducting research into their state of mind prior to death.

The psychological autopsy report provides detailed information about the death using various sources including the autopsy report, medical records, relevant documents and information gathered from interviews with key informants.

It was conceived as a means to help forensic pathologists clarify the nature of deaths regarded as unresolved and that could be associated with natural or accidental causes, suicide or homicide. The method was also used to investigate the reasons behind self-inflicted deaths and to provide comfort to family members of individuals who have died this way.

#### **2.1 Psychosocial autopsy**

Psychosocial autopsy is understanding of emotional, social, economic and cultural reasons and circumstances associated with suicide among individuals. The aim is to investigate and analyze the relevance of interacting variables.

Some of the key goals of the Psychological Autopsy:

Obtaining an in-depth understanding of the decedent's personality, behavior patterns, and possible motives for suicide; identify behavior patterns—reactions to stress, adaptability, changes in habits or routine Establish presence or absence of mental illness.

#### **3. Methodological issues in studying clusters**

The demographic and clinical features of suicide cluster victims have been described by researchers. Only some studies [19, 27] adopt a more methodologically robust design, such as case–control study. Only a small number of possible risk factors for suicide were examined, like gender, age-group, marital status, area of residence, method of suicide. Studies using multi-level methodology are needed to determine which individual or contextual factors contribute to clustering of suicidal behavior. Longitudinal studies on suicide clusters combined with environmental factors are needed. It is not always possible to determine retrospectively whether or not a person in a suicide cluster knew about the suicide of another cluster member [28].

#### **4. Prevention strategies**

Suicide is often related to depression, social isolation and loss of meaning in life. Some strategies at the individual level are:


**185**

*Psychosocial Autopsy of Mass Suicides: Changing Patterns in Contemporary Times*

5.Offer case-management services at schools and universities.

6.Provide mental health screening for depression and suicide.

7.Share information about mental health with parents.

responsible for suicide, people who were in suicide pact, people who were

3.Screen those at high risk, screening by trained counselors, screening for emotional and mental health problems, symptoms of depression and suicide risk.

4.Provide post-care after suicide counseling by crisis counselors available in schools and make sure students know these resources are readily available.

Mass suicides can be prevented at community level by designing of strategies by community leaders. All sectors of the community need to be included: public health, mental health, Education, Local government, parent groups, media, as no single agency has the requisite expertise to deal with the suicide cluster. The plans need to be adapted to the particular needs, resources and cultural characteristics of the community. Suicide prevention training needs to be provided in schools. Peer-helping needs to be encouraged. It is based on the premise that an informal helping network exists. This group teaches how to reach out adults for help. Tele-health services need to be in places which are manned by counselors, mental health clinicians, social workers and clinical psychologists. Having counselors on the sites of memorials, suicide anniversaries and other events related to suicides can also be of great help. Addressing the environment, e.g. the internet environment and how students interact with each other on the net is also needed. Mass suicides can impact those living in the community deeply. Hence strategies at the community level have a

The cultural/social resources include guidance from elders for addressing grief, informal community gatherings, where community members share stories and draw on a shared sense of spirituality and cultural history to overcome crises and impact of suicides and suicide clusters. The elders can pass on the wisdom and traditions on how to thrive through harsh conditions. The mutual care and concern for others, shared purpose. Spirituality helps to a great extent in dealing with traumas of life. Traditional culture helps to ground individuals and provide a framework to view their place in the world. Communities need to connect youth to their culture. Elders can share stories of how they used to deal with crisis situations in the past before our generation. School–based programs need to be organized on suicide signs and risk factors. Developing and promoting prosocial adult and peer mentors and role models are likely to help in a great way. Culture camps can be organized where youth (at

Psychological autopsy studies have found that media can be of great help by not publishing/telecasting the method used to kill oneself, not suggesting that the death

community and school level) are exposed to their traditional life ways.

*DOI: http://dx.doi.org/10.5772/intechopen.89439*

previously suicidal.

**4.1 Community level**

great role to play.

**4.2 Role of culture**

**4.3 Role of media**

responsible for suicide, people who were in suicide pact, people who were previously suicidal.


#### **4.1 Community level**

*Neurological and Mental Disorders*

**2. Methods of suicide study**

state of mind prior to death.

als who have died this way.

**2.1 Psychosocial autopsy**

**4. Prevention strategies**

Some strategies at the individual level are:

who is trained in crisis care therapy.

mental illness.

Two prominent methods are psychological and psychosocial autopsy.

ments and information gathered from interviews with key informants.

aim is to investigate and analyze the relevance of interacting variables.

Some of the key goals of the Psychological Autopsy:

**3. Methodological issues in studying clusters**

[26]. It has become widespread in the last 2–3 decades.

In depth study of the history of suicide prior to the suicidal act is known as psychological autopsy [25]. Psychological autopsy is a method created by Shneidman

Psychological autopsy is a depth study of a person's mental state by analyzing medical records, interviewing friends and family and conducting research into their

The psychological autopsy report provides detailed information about the death using various sources including the autopsy report, medical records, relevant docu-

It was conceived as a means to help forensic pathologists clarify the nature of deaths regarded as unresolved and that could be associated with natural or accidental causes, suicide or homicide. The method was also used to investigate the reasons behind self-inflicted deaths and to provide comfort to family members of individu-

Psychosocial autopsy is understanding of emotional, social, economic and cultural reasons and circumstances associated with suicide among individuals. The

Obtaining an in-depth understanding of the decedent's personality, behavior patterns, and possible motives for suicide; identify behavior patterns—reactions to stress, adaptability, changes in habits or routine Establish presence or absence of

The demographic and clinical features of suicide cluster victims have been described by researchers. Only some studies [19, 27] adopt a more methodologically robust design, such as case–control study. Only a small number of possible risk factors for suicide were examined, like gender, age-group, marital status, area of residence, method of suicide. Studies using multi-level methodology are needed to determine which individual or contextual factors contribute to clustering of suicidal behavior. Longitudinal studies on suicide clusters combined with environmental factors are needed. It is not always possible to determine retrospectively whether or not a person in a suicide cluster knew about the suicide of another cluster member [28].

Suicide is often related to depression, social isolation and loss of meaning in life.

1.Talk to those intimately connected first prior to media coverage, possibly one

2.Identify vulnerable persons for mass/cluster suicides, e.g. people who had a negative interaction with the person before suicide and feel that they were

**184**

Mass suicides can be prevented at community level by designing of strategies by community leaders. All sectors of the community need to be included: public health, mental health, Education, Local government, parent groups, media, as no single agency has the requisite expertise to deal with the suicide cluster. The plans need to be adapted to the particular needs, resources and cultural characteristics of the community. Suicide prevention training needs to be provided in schools. Peer-helping needs to be encouraged. It is based on the premise that an informal helping network exists. This group teaches how to reach out adults for help. Tele-health services need to be in places which are manned by counselors, mental health clinicians, social workers and clinical psychologists. Having counselors on the sites of memorials, suicide anniversaries and other events related to suicides can also be of great help.

Addressing the environment, e.g. the internet environment and how students interact with each other on the net is also needed. Mass suicides can impact those living in the community deeply. Hence strategies at the community level have a great role to play.

#### **4.2 Role of culture**

The cultural/social resources include guidance from elders for addressing grief, informal community gatherings, where community members share stories and draw on a shared sense of spirituality and cultural history to overcome crises and impact of suicides and suicide clusters. The elders can pass on the wisdom and traditions on how to thrive through harsh conditions. The mutual care and concern for others, shared purpose. Spirituality helps to a great extent in dealing with traumas of life. Traditional culture helps to ground individuals and provide a framework to view their place in the world. Communities need to connect youth to their culture. Elders can share stories of how they used to deal with crisis situations in the past before our generation. School–based programs need to be organized on suicide signs and risk factors. Developing and promoting prosocial adult and peer mentors and role models are likely to help in a great way. Culture camps can be organized where youth (at community and school level) are exposed to their traditional life ways.

#### **4.3 Role of media**

Psychological autopsy studies have found that media can be of great help by not publishing/telecasting the method used to kill oneself, not suggesting that the death was due to a similar reason or achieved a goal such as fame or revenge and listing resources to those who are struggling.

#### **4.4 Addressing the symptoms of mental illness**

Treatment of mental illness can reduce the risk for suicide and increase the quality of life. One needs to be beware of warning signs like increased use of drugs/ alcohol, statements threatening to hurt self, looking for access to fire arms, pills etc. statements of hopelessness, helplessness etc., increased anger and rage, highly reckless behavior, paired with recent losses, including deaths, break-ups, job or financial losses.

### **5. Conclusions**

Mass suicide in across the globe is an age-old act which was carried out by individuals and was neither condemned nor glorified nor seen as a crime. The intent of the act determined its approval or disapproval. With the change in scenario, more number of cluster suicides has been reported in the present Indian society which can be categorized into family, farmers and students. Psychosocial autopsy has revealed imitation, suggestibility, contagion, lack of social integration, priming, associative susceptibility, guilt, mental illness and a host of other causes behind this act. Preventive strategies need to be addressed at individual, community and cultural level. In future, more methodologically sound and preferably longitudinal studies are needed to gain better insight into this suicide type so that preventive strategies can be targeted appropriately.

#### **Author details**

Nishi Misra\*, Harshita Jha and Komal Tiwari Defence Institute of Psychological Research (DIPR), Delhi, India

\*Address all correspondence to: nishi.nishi067@gmail.com

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**187**

*Psychosocial Autopsy of Mass Suicides: Changing Patterns in Contemporary Times*

[10] Joiner JE. The clustering and

in Psychological Science (Wiley-

[11] Rezaeian M. Suicide clusters: Introducing a novel type of

categorization. Violence and Victims.

[12] Cox G, Robinson J, Williamson M, Lockley A, Cheung Y, Pirkis J. Suicide clusters in young people: Evidence for the effectiveness of postvention strategies. Crisis. 2012;**33**(4):208-214

[13] Hanssens L. "Echo- cluster" are they a unique phenomenon of indigenous attempted and complete suicide? Aboriginal and Islander Health Worker

[14] Gunnar M. Asian Drama. New York:

[15] Wasserman D. Imitation and suicide: A re-examination of the Werther effect. American Sociological

[16] Phillips DP. The influence of suggestion on suicide: Substantive and theoretical implications of the Werther effect. American Sociological Review.

[17] Berkowitz L. Some effects of thoughts on anti- and prosocial influence of media events: A cognitive neo-associationist analysis. Psychological Bulletin.

[18] Durkheim E. Suicide. Translated by John a. Spaulding 1951 and George Simpson. New York: Free Press; 1897

[19] Chotai J. Suicide aggregation in relation to socio-demographic variables and the suicide method in a general population: Assortative susceptibility.

Journal. 2010;**34**(1):17-26

Review. 1984;**49**:427-436

Pantheon; 1968

1974;**39**:340-354

1984;**95**:410-427

Blackwell). 1999;**8**(3):89

2012;**27**(1):125-132

contagion of suicide. Current Directions

*DOI: http://dx.doi.org/10.5772/intechopen.89439*

[1] Ravi S. A reality check of suicides in India. In: Brookings India IMPACT Series. New Delhi: Brookings Institution

[2] WHO retrieved from http://www. searo.who.int/india/topics/suicide/en on

[3] Nrugham L. Suicide in Indian hindu scriptures: Condemned or glorified. In: Kumar U, editor. Handbook of Suicidal Behaviour. Nature Singapore: Springer;

[4] Somasundaram O, Murthy AGT, Raghavan DV. Jainism – Its relevance to psychiatric practice; with special reference to the practice of Sallekhana.

[5] Zeller BE. Heaven's Gate: America's UFO Religion. NYU Press; 2014

[6] Mancinelli I, Comparelli A, Giradi P, Tatarelli R. Mass suicide: Historical and psychodynamic considerations. Suicide and Life Threatening Behaviour.

[7] Larkin GL, Beautrais A. Geospatial Mapping of Suicide Clusters. Auckland:

Te Pou o Te Whakaaro Nui, the National Centre of Mental Health Research, Information and Workforce

[8] Arensman E, Mc Auliffe C. Clustering and contagion of suicidal behaviour. In: Kumar U, editor. Suicidal Behaviour: Underlying Dynamics. London, UK: Routledge; 2015.

[9] Haw C, Hawton K, Niedzwiedz C, Platt S. Suicide clusters: A review of risk factors and mechanisms. Suicide and Life-threatening Behavior.

Indian Journal of Psychiatry.

2016;**58**(4):471-474

2002;**32**(1):91-100

Development; 2012

pp. 110-120

2013;**43**(1):97-108

India Center; 2015. pp. 6-7

19 Jun 2019

**References**

2017. pp. 23-37

*Psychosocial Autopsy of Mass Suicides: Changing Patterns in Contemporary Times DOI: http://dx.doi.org/10.5772/intechopen.89439*

#### **References**

*Neurological and Mental Disorders*

financial losses.

**5. Conclusions**

resources to those who are struggling.

strategies can be targeted appropriately.

Nishi Misra\*, Harshita Jha and Komal Tiwari

provided the original work is properly cited.

Defence Institute of Psychological Research (DIPR), Delhi, India

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: nishi.nishi067@gmail.com

**4.4 Addressing the symptoms of mental illness**

was due to a similar reason or achieved a goal such as fame or revenge and listing

Treatment of mental illness can reduce the risk for suicide and increase the quality of life. One needs to be beware of warning signs like increased use of drugs/ alcohol, statements threatening to hurt self, looking for access to fire arms, pills etc. statements of hopelessness, helplessness etc., increased anger and rage, highly reckless behavior, paired with recent losses, including deaths, break-ups, job or

Mass suicide in across the globe is an age-old act which was carried out by individuals and was neither condemned nor glorified nor seen as a crime. The intent of the act determined its approval or disapproval. With the change in scenario, more number of cluster suicides has been reported in the present Indian society which can be categorized into family, farmers and students. Psychosocial autopsy has revealed imitation, suggestibility, contagion, lack of social integration, priming, associative susceptibility, guilt, mental illness and a host of other causes behind this act. Preventive strategies need to be addressed at individual, community and cultural level. In future, more methodologically sound and preferably longitudinal studies are needed to gain better insight into this suicide type so that preventive

**186**

**Author details**

[1] Ravi S. A reality check of suicides in India. In: Brookings India IMPACT Series. New Delhi: Brookings Institution India Center; 2015. pp. 6-7

[2] WHO retrieved from http://www. searo.who.int/india/topics/suicide/en on 19 Jun 2019

[3] Nrugham L. Suicide in Indian hindu scriptures: Condemned or glorified. In: Kumar U, editor. Handbook of Suicidal Behaviour. Nature Singapore: Springer; 2017. pp. 23-37

[4] Somasundaram O, Murthy AGT, Raghavan DV. Jainism – Its relevance to psychiatric practice; with special reference to the practice of Sallekhana. Indian Journal of Psychiatry. 2016;**58**(4):471-474

[5] Zeller BE. Heaven's Gate: America's UFO Religion. NYU Press; 2014

[6] Mancinelli I, Comparelli A, Giradi P, Tatarelli R. Mass suicide: Historical and psychodynamic considerations. Suicide and Life Threatening Behaviour. 2002;**32**(1):91-100

[7] Larkin GL, Beautrais A. Geospatial Mapping of Suicide Clusters. Auckland: Te Pou o Te Whakaaro Nui, the National Centre of Mental Health Research, Information and Workforce Development; 2012

[8] Arensman E, Mc Auliffe C. Clustering and contagion of suicidal behaviour. In: Kumar U, editor. Suicidal Behaviour: Underlying Dynamics. London, UK: Routledge; 2015. pp. 110-120

[9] Haw C, Hawton K, Niedzwiedz C, Platt S. Suicide clusters: A review of risk factors and mechanisms. Suicide and Life-threatening Behavior. 2013;**43**(1):97-108

[10] Joiner JE. The clustering and contagion of suicide. Current Directions in Psychological Science (Wiley-Blackwell). 1999;**8**(3):89

[11] Rezaeian M. Suicide clusters: Introducing a novel type of categorization. Violence and Victims. 2012;**27**(1):125-132

[12] Cox G, Robinson J, Williamson M, Lockley A, Cheung Y, Pirkis J. Suicide clusters in young people: Evidence for the effectiveness of postvention strategies. Crisis. 2012;**33**(4):208-214

[13] Hanssens L. "Echo- cluster" are they a unique phenomenon of indigenous attempted and complete suicide? Aboriginal and Islander Health Worker Journal. 2010;**34**(1):17-26

[14] Gunnar M. Asian Drama. New York: Pantheon; 1968

[15] Wasserman D. Imitation and suicide: A re-examination of the Werther effect. American Sociological Review. 1984;**49**:427-436

[16] Phillips DP. The influence of suggestion on suicide: Substantive and theoretical implications of the Werther effect. American Sociological Review. 1974;**39**:340-354

[17] Berkowitz L. Some effects of thoughts on anti- and prosocial influence of media events: A cognitive neo-associationist analysis. Psychological Bulletin. 1984;**95**:410-427

[18] Durkheim E. Suicide. Translated by John a. Spaulding 1951 and George Simpson. New York: Free Press; 1897

[19] Chotai J. Suicide aggregation in relation to socio-demographic variables and the suicide method in a general population: Assortative susceptibility.

Nordic Journal of Psychiatry. 2005;**59**(5):325-330

[20] Vijayakumar L. Suicide and its prevention: The urgent need in India. Indian Journal of Psychiatry. 2007;**49**:81-84

[21] Radhakrishnan R, Andrade C. Suicide: An Indian perspective. Indian Journal of Psychiatry. 2012;**54**(4):304-319

[22] National Crime Records Bureau. 2009. Available from: data.gov.in

[23] Ponnudurai R, Jeyakar J, Saraswathy M. Attempted suicides in Madras. Indian Journal of Psychiatry. 1986;**28**:59-62

[24] Davies D, Wilkes TCR. Cluster suicide in rural Western Canada. Canadian Journal of Psychiatry. 1993;**38**:515-519

[25] Unni KE. Human self-destructive behaviour. In: Vyas JN, Ahuja N, editors. Postgraduate Psychiatry. Jaypee Brothers Medical Publishers: New Delhi; 1999. pp. 526-556

[26] Shneidman ES. Suicide thoughts and reflections, 1960-1980. Suicide Life-Threatening Behaviour. 1981;**11**:195-364

[27] Davidson, L, Suicide clusters: A critical review. Suicide and Lifethreatening Behavior, 1989; 19: 17-27. GOU

[28] McKenzie N, Landau S, Kapur N, Meehan J, Robinson J, Bickley H, et al. Clustering of suicides among people with mental illness. British Journal of Psychiatry. 2005;**187**:476-480

**189**

**Chapter 12**

**Abstract**

relational memory

**1. Introduction**

*Eugenia Marin-Garcia*

Neurocognitive Perspective of

Transient global amnesia (TGA) is a neuropsychological syndrome that involves a sudden and temporary episode of memory loss that includes inability to create new memories. It has been shown that this disorder is related with a transitory deficit of the hippocampus function. In this chapter, the preserved and impaired memory pattern of TGA patients will be discussed considering the classical memory systems model. The analysis of this perspective leads to some contradictory or unresolved issues. In order to try to resolve these inconsistencies and considering that TGA is associated with hippocampal perturbation, new research about the hippocampus is analyzed. This new perspective focused on the hippocampal function provides a deeper understanding of the memory loss pattern associated with TGA, and it points out new questions that are not studied yet in the TGA population.

**Keywords:** transient global amnesia, anterograde amnesia, retrograde amnesia, hippocampus, memory systems, spatial representation, temporal representation,

Transient global amnesia (TGA) is a neuropsychological syndrome, which shows a severe, sudden, and transitory loss of the ability to create new memories and, to some degree, to recover past events [1, 2]. The main goal of this chapter is to provide a neurocognitive perspective of the deficits and preserved abilities of this type of amnesia. Cognitive neuroscience is the scientific field that studies the neural bases of the cognitive processes as memory and learning [3]. As it has been shown that TGA is related with a transitory deficit of the hippocampus function, in this chapter the cognitive consequences of this deficit will be discussed. These consequences are going to be framed in a classical memory systems perspective, which considers that the hippocampus is engaged in declarative and explicit memory but not in non-declarative and implicit memory. This perspective leads to some inconsistencies and unresolved issues that will be confronted having a more precise and updated description of the function of the hippocampus. The chapter starts with a review of basic characteristics of TGA including diagnostic criteria, etiology, and differential diagnosis. Then, the preserved and impaired memory pattern of TGA patients will be discussed considering the classical memory systems model. This includes both, the analysis of the ability of the TGA patients to recall knowledge acquired before the TGA (retrograde amnesia) and to learn new knowledge during the amnesic episode (anterograde amnesia). And finally, based on new insights from the hippocampal function research, some inconsistencies derived from the memory systems perspective will be analyzed.

Transient Global Amnesia

#### **Chapter 12**

*Neurological and Mental Disorders*

Nordic Journal of Psychiatry.

[20] Vijayakumar L. Suicide and its prevention: The urgent need in India. Indian Journal of Psychiatry.

[21] Radhakrishnan R, Andrade C. Suicide: An Indian perspective. Indian Journal of Psychiatry.

[22] National Crime Records Bureau. 2009. Available from: data.gov.in

Saraswathy M. Attempted suicides in Madras. Indian Journal of Psychiatry.

[24] Davies D, Wilkes TCR. Cluster suicide in rural Western Canada. Canadian Journal of Psychiatry.

[25] Unni KE. Human self-destructive behaviour. In: Vyas JN, Ahuja N, editors. Postgraduate Psychiatry. Jaypee Brothers Medical Publishers: New Delhi; 1999.

[26] Shneidman ES. Suicide thoughts and reflections, 1960-1980. Suicide Life-Threatening Behaviour. 1981;**11**:195-364

[27] Davidson, L, Suicide clusters: A critical review. Suicide and Lifethreatening Behavior, 1989; 19: 17-27.

[28] McKenzie N, Landau S, Kapur N, Meehan J, Robinson J, Bickley H, et al. Clustering of suicides among people with mental illness. British Journal of

Psychiatry. 2005;**187**:476-480

[23] Ponnudurai R, Jeyakar J,

2005;**59**(5):325-330

2007;**49**:81-84

2012;**54**(4):304-319

1986;**28**:59-62

1993;**38**:515-519

pp. 526-556

GOU

**188**

## Neurocognitive Perspective of Transient Global Amnesia

*Eugenia Marin-Garcia*

#### **Abstract**

Transient global amnesia (TGA) is a neuropsychological syndrome that involves a sudden and temporary episode of memory loss that includes inability to create new memories. It has been shown that this disorder is related with a transitory deficit of the hippocampus function. In this chapter, the preserved and impaired memory pattern of TGA patients will be discussed considering the classical memory systems model. The analysis of this perspective leads to some contradictory or unresolved issues. In order to try to resolve these inconsistencies and considering that TGA is associated with hippocampal perturbation, new research about the hippocampus is analyzed. This new perspective focused on the hippocampal function provides a deeper understanding of the memory loss pattern associated with TGA, and it points out new questions that are not studied yet in the TGA population.

**Keywords:** transient global amnesia, anterograde amnesia, retrograde amnesia, hippocampus, memory systems, spatial representation, temporal representation, relational memory

#### **1. Introduction**

Transient global amnesia (TGA) is a neuropsychological syndrome, which shows a severe, sudden, and transitory loss of the ability to create new memories and, to some degree, to recover past events [1, 2]. The main goal of this chapter is to provide a neurocognitive perspective of the deficits and preserved abilities of this type of amnesia. Cognitive neuroscience is the scientific field that studies the neural bases of the cognitive processes as memory and learning [3]. As it has been shown that TGA is related with a transitory deficit of the hippocampus function, in this chapter the cognitive consequences of this deficit will be discussed. These consequences are going to be framed in a classical memory systems perspective, which considers that the hippocampus is engaged in declarative and explicit memory but not in non-declarative and implicit memory. This perspective leads to some inconsistencies and unresolved issues that will be confronted having a more precise and updated description of the function of the hippocampus.

The chapter starts with a review of basic characteristics of TGA including diagnostic criteria, etiology, and differential diagnosis. Then, the preserved and impaired memory pattern of TGA patients will be discussed considering the classical memory systems model. This includes both, the analysis of the ability of the TGA patients to recall knowledge acquired before the TGA (retrograde amnesia) and to learn new knowledge during the amnesic episode (anterograde amnesia). And finally, based on new insights from the hippocampal function research, some inconsistencies derived from the memory systems perspective will be analyzed.

#### **2. Transient global amnesia**

#### **2.1 Diagnostic criteria**

In order to have a clear diagnosis of the TGA, the following diagnostic criteria [4, 5] must be fulfilled: (a) there must be clear anterograde amnesia (inability to create new memories) during the attack that it is witnessed by an observer. (b) Consciousness loss and personal identity loss must be absent, and the cognitive impairment must be limited to the amnesia. (c) The patient's neurological examination is otherwise normal. No signs of pathology should appear in the electroencephalogram (EEG) of the TGA patient, with no epileptic-form activity or postictal abnormalities [6]. (d) Epileptic features must be absent. (e) Patients with recent history of head trauma or seizures must be excluded from this diagnosis. (f) The amnesic episode must be resolved within 24 hours. (g) Mild vegetative symptoms (headache, nausea, or dizziness) might be present during the acute phase [7].

#### **2.2 Epidemiology**

Concerning TGA epidemiology, the annual TGA incidence varies between 3 and 10 per 100,000 in different studies [5, 8–11]. In population older than 50 years old, the TGA rate increases until 23–32/100,000 [9, 10], and it is very rare before 40 [5]. The second TGA episode recurrence rate varies between 6 and 15% [9, 12]; thus it is not very frequent to have another episode.

#### **2.3 Characteristics of a TGA episode**

During TGA, patients show severe anterograde amnesia, which makes them unable to create new memories and to have the sense of present. This makes them disoriented in space and specifically in time, but they do not produce confabulations (false memories which are taken by the patient as true to fill the gaps in memory) [13]. In a study with 17 TGA patients, there were no significant differences in spatial orientation with the control group, while the temporal orientation was severely affected during the amnesic episode, and it was recovered after a week [14]. This difference between spatial and temporal disorientation may be reflecting their ability to use contextual information and previous semantic knowledge to make inferences about where they are. But those inferences were not helpful enough to make them orientate in time. During amnesic episode, patients maintain their attention, and they are able to perform complex tasks as gardening or driving [15, 16]. Patients usually are aware of their disease state, but they are unable to identify the nature of their memory deficits and they overestimate their memory ability [14, 17].

Witnesses of TGA episode usually report a sudden expressive or behavioral change in the patient [18]. A characteristic feature of TGA is the repetitive comments or questions that are repeated using the same words and making the same comments to the answers that they receive [13]. The episode lasts some hours and then the memory is recovered gradually. But the memory of the period of the amnesic episode is never recovered.

#### **2.4 TGA settings**

The settings where the TGA episode usually occurs include immersion in water, temperature change, painful experiences (e.g., renal pain [19]), physical activity, emotional stress (e.g., increased work load [5, 20]), sexual intercourse [21], driving and traveling, medical procedures, Valsalva-associated maneuvers, and

**191**

*Neurocognitive Perspective of Transient Global Amnesia DOI: http://dx.doi.org/10.5772/intechopen.88810*

[12] with more than 800 patients in each review.

campal perturbations remain unclear.

high frequency of the amnesic episodes [6].

situations as neurotoxicity [44].

**2.5 Etiology**

other activities as walks, house works, meetings, etc. [12, 17, 22–27]. In most of the settings, the patient is doing a routine or automatized activity and usually is alone or not in an active communication with others. Thus, it seems that patients are in a default functioning state. Additionally, certain personality traits have been related with the TGA as psychological or emotional instability [12] and higher occurrence of personal or family history of psychiatric disorders [28]. TGA has been associated with the intake of different substances such as sildenafil, vasodilator drug for erectile dysfunction [29, 30], or ergotic drugs to treat migraine. But in both cases, it could be a coincidence of events, drug intake and amnesia, and not a causal relationship between them [31]. It is important to consider that the percentage of TGA without a triggering factor or special setting is high, between 44% [24] and 52%

MRI data suggest that during the TGA there is a temporary perturbation of the hippocampal function, mainly in the CA1 field of the hippocampus [6, 22]. Various factors such as migraine and vascular abnormalities have been suggested to be involved in the TGA etiology, but the causal mechanisms underlying these hippo-

Several studies have reported a higher incidence of migraine in patients with TGA than healthy, age-marched controls [4, 12, 23, 32–34]. But patients do not usually have migraine episodes before TGA or migrainous features during TGA episode. TGA usually occurs after 50 years old, while migraine appears through the life-span [35] and migraine is a recurrent disease, and TGA usually has only one episode [28]. Thus, migraine could be a risk factor for TGA, and its correlation could reflect a sharing mechanism [36] but probably is not a direct cause of a typical TGA.

Some studies have related TGA with ischemic deficits, but even there are cases of transient amnesia with ischemic etiology (transient ischemic amnesia (TIA)) [1, 8], they do not share many characteristic with TGA. For example, TIA is associated with stroke risk factors that are not common in TGA patients [5, 7, 12, 32, 34, 37], and TGA patients usually do not develop cerebrovascular diseases [9, 15, 33].

Another transient amnesia is transient epileptic amnesia [38], which is caused by focal seizure activity, and it can be differentiated from TGA by the briefness and

Some data suggests that the impairment of the hippocampal function during TGA may be related to the metabolic stress of the hippocampal neurons [22]. This stress-related change may trigger a hypometabolic event associated with the *cortical spreading depression*, which is described as a short-lasting depolarization wave followed by neuronal depression and regionally decreased blood flow [22, 39]. In support to this idea, decreased oxygen and cerebral blood flow in the temporal region has been reported in TGA patients [40–43]. Furthermore, CA1 region of the hippocampus shows a selective vulnerability to metabolic stress caused by different

In the same direction, Kessler et al. [45] proposed that TGA might be related with the biochemical imbalance associated with psychological stress and anxiety through the increase of stress hormones' level. There is an overlap between the brain areas affected during TGA, as hippocampus, and regions with high density of glucocorticoid receptors, which are stress hormones [45]. In fact, a special sensitivity of the TGA patients to psychological stress [12] and high prevalence of emotional stress in these patients have been suggested [32]. Additionally, several studies have pointed out that emotional, physical, and behavioral stress situations lead to the onset of TGA in many cases [22]. And studies on the animal hippocampus

other activities as walks, house works, meetings, etc. [12, 17, 22–27]. In most of the settings, the patient is doing a routine or automatized activity and usually is alone or not in an active communication with others. Thus, it seems that patients are in a default functioning state. Additionally, certain personality traits have been related with the TGA as psychological or emotional instability [12] and higher occurrence of personal or family history of psychiatric disorders [28]. TGA has been associated with the intake of different substances such as sildenafil, vasodilator drug for erectile dysfunction [29, 30], or ergotic drugs to treat migraine. But in both cases, it could be a coincidence of events, drug intake and amnesia, and not a causal relationship between them [31]. It is important to consider that the percentage of TGA without a triggering factor or special setting is high, between 44% [24] and 52% [12] with more than 800 patients in each review.

#### **2.5 Etiology**

*Neurological and Mental Disorders*

**2. Transient global amnesia**

In order to have a clear diagnosis of the TGA, the following diagnostic criteria [4, 5] must be fulfilled: (a) there must be clear anterograde amnesia (inability to create new memories) during the attack that it is witnessed by an observer. (b) Consciousness loss and personal identity loss must be absent, and the cognitive impairment must be limited to the amnesia. (c) The patient's neurological examination is otherwise normal. No signs of pathology should appear in the electroencephalogram (EEG) of the TGA patient, with no epileptic-form activity or postictal abnormalities [6]. (d) Epileptic features must be absent. (e) Patients with recent history of head trauma or seizures must be excluded from this diagnosis. (f) The amnesic episode must be resolved within 24 hours. (g) Mild vegetative symptoms (headache, nausea, or dizziness) might be present during the acute phase [7].

Concerning TGA epidemiology, the annual TGA incidence varies between 3 and 10 per 100,000 in different studies [5, 8–11]. In population older than 50 years old, the TGA rate increases until 23–32/100,000 [9, 10], and it is very rare before 40 [5]. The second TGA episode recurrence rate varies between 6 and 15% [9, 12]; thus it is

During TGA, patients show severe anterograde amnesia, which makes them unable to create new memories and to have the sense of present. This makes them disoriented in space and specifically in time, but they do not produce confabulations (false memories which are taken by the patient as true to fill the gaps in memory) [13]. In a study with 17 TGA patients, there were no significant differences in spatial orientation with the control group, while the temporal orientation was severely affected during the amnesic episode, and it was recovered after a week [14]. This difference between spatial and temporal disorientation may be reflecting their ability to use contextual information and previous semantic knowledge to make inferences about where they are. But those inferences were not helpful enough to make them orientate in time. During amnesic episode, patients maintain their attention, and they are able to perform complex tasks as gardening or driving [15, 16]. Patients usually are aware of their disease state, but they are unable to identify the nature of

their memory deficits and they overestimate their memory ability [14, 17].

Witnesses of TGA episode usually report a sudden expressive or behavioral change in the patient [18]. A characteristic feature of TGA is the repetitive comments or questions that are repeated using the same words and making the same comments to the answers that they receive [13]. The episode lasts some hours and then the memory is recovered gradually. But the memory of the period of the

The settings where the TGA episode usually occurs include immersion in water,

temperature change, painful experiences (e.g., renal pain [19]), physical activity, emotional stress (e.g., increased work load [5, 20]), sexual intercourse [21], driving and traveling, medical procedures, Valsalva-associated maneuvers, and

**2.1 Diagnostic criteria**

**2.2 Epidemiology**

not very frequent to have another episode.

**2.3 Characteristics of a TGA episode**

amnesic episode is never recovered.

**2.4 TGA settings**

**190**

MRI data suggest that during the TGA there is a temporary perturbation of the hippocampal function, mainly in the CA1 field of the hippocampus [6, 22]. Various factors such as migraine and vascular abnormalities have been suggested to be involved in the TGA etiology, but the causal mechanisms underlying these hippocampal perturbations remain unclear.

Several studies have reported a higher incidence of migraine in patients with TGA than healthy, age-marched controls [4, 12, 23, 32–34]. But patients do not usually have migraine episodes before TGA or migrainous features during TGA episode. TGA usually occurs after 50 years old, while migraine appears through the life-span [35] and migraine is a recurrent disease, and TGA usually has only one episode [28]. Thus, migraine could be a risk factor for TGA, and its correlation could reflect a sharing mechanism [36] but probably is not a direct cause of a typical TGA.

Some studies have related TGA with ischemic deficits, but even there are cases of transient amnesia with ischemic etiology (transient ischemic amnesia (TIA)) [1, 8], they do not share many characteristic with TGA. For example, TIA is associated with stroke risk factors that are not common in TGA patients [5, 7, 12, 32, 34, 37], and TGA patients usually do not develop cerebrovascular diseases [9, 15, 33].

Another transient amnesia is transient epileptic amnesia [38], which is caused by focal seizure activity, and it can be differentiated from TGA by the briefness and high frequency of the amnesic episodes [6].

Some data suggests that the impairment of the hippocampal function during TGA may be related to the metabolic stress of the hippocampal neurons [22]. This stress-related change may trigger a hypometabolic event associated with the *cortical spreading depression*, which is described as a short-lasting depolarization wave followed by neuronal depression and regionally decreased blood flow [22, 39]. In support to this idea, decreased oxygen and cerebral blood flow in the temporal region has been reported in TGA patients [40–43]. Furthermore, CA1 region of the hippocampus shows a selective vulnerability to metabolic stress caused by different situations as neurotoxicity [44].

In the same direction, Kessler et al. [45] proposed that TGA might be related with the biochemical imbalance associated with psychological stress and anxiety through the increase of stress hormones' level. There is an overlap between the brain areas affected during TGA, as hippocampus, and regions with high density of glucocorticoid receptors, which are stress hormones [45]. In fact, a special sensitivity of the TGA patients to psychological stress [12] and high prevalence of emotional stress in these patients have been suggested [32]. Additionally, several studies have pointed out that emotional, physical, and behavioral stress situations lead to the onset of TGA in many cases [22]. And studies on the animal hippocampus

have shown that emotional and behavioral stresses impair long-term potentiation and enhance long-term depression in CA1 neurons, disturbing the hippocampusdependent memory [46].

In conclusion, the causal mechanisms underlying hippocampal perturbations of TGA remain unclear, but it seems probable that TGA is related with metabolic stress of hippocampal neurons.

#### **3. Memory systems and TGA**

Traditionally, a memory system perspective has been used to describe which processes are affected and preserved during amnesia. From this perspective, memory is considered as a not unitary entity, with relatively independent but interacting systems that process different types of information, which have different cognitive rules and that are implemented in specific cerebral networks [47]. In order to define this systems, animal and human, behavioral, clinical, neuropsychological, and neuroimaging studies have been used [48–50]. The combination of these findings has helped to classify the different memory systems.

In order to describe the complexity of memory, initially binary models were suggested. Cohen and Squire [51] proposed that long-term memory could be subdivided between declarative memory, which is representational, can be verbalized, and is severely impaired during amnesia, and procedural memory, which is expressed through action, is independent from conscious awareness, and is preserved during amnesia. On the other hand, Graf et al. [52] suggested that long-term memory is divided into implicit memory that is acquired and used unconsciously and explicit memory that is conscious and intentional.

Later, a more complex model was proposed, which is considered a classical classification model of memory systems [47, 53]. This model includes the following memory systems: episodic memory, working memory, semantic memory, priming, and procedural memory. This proposal assumes that there is a continuum between explicit/implicit and declarative/procedural dimensions through different memory systems. In the following sections, each system will be defined, and the impairments and preservation pattern associated with the TGA will be described.

#### **3.1 Procedural memory**

Procedural memory is the system that allows no-conscious acquisition, maintenance, and the use of motor and cognitive skills. It is characterized by gradual or progressive acquisition, which typically results in increased speed or accuracy with repetition. It includes heterogeneous set of subsystems: motor and cognitive abilities, habits, conditioning, and nonassociative learning. It is implicit and non-declarative, it is not hippocampal dependent, and it is spared in amnesia [53].

#### *3.1.1 Skills acquired before the TGA*

During the TGA episode, patients are able to perform complex but automatized activities learnt before the attack. For example, they are able to play the organ [54], conduct a talk [17], cook [24], drive a car [55], or conduct a concert [56]. These and similar activities, which are usually quite complex, when becoming routine procedures no longer need the involvement of the hippocampus. Thus, during the TGA procedural memories acquired before the TGA tend to be preserved [56].

**193**

*Neurocognitive Perspective of Transient Global Amnesia DOI: http://dx.doi.org/10.5772/intechopen.88810*

group.

anterograde memory loss [27].

be described in Section 3.

the word "frog."

completion task [40].

**3.3 Semantic memory**

affected in amnesia [63].

**3.2 Perceptual representation system**

*3.1.2 Acquisition of new procedural skills during the TGA*

In addition, the ability to learn new procedural skills remains preserved as well during TGA episode. For example, Eustache et al. [40] showed that TGA patients are able to acquire mirror-reading skill at the same learning speed as the control

Another example of implicit learning phenomenon is the mere exposure effect, which is defined as preference enhancement to previously exposed stimuli [57]. Mere exposure effect is preserved in TGA patients during the amnesic episode, showing enhanced preference for previously exposed faces, in spite of the severe

Classical conditioning is another subtype of procedural memory that is based on associative learning. In classical conditioning, repeated pairings of a neutral conditioned stimulus (CS), such as a tone, and an unconditioned stimulus (US) such as an air-puff to the eye result in the CS alone, eliciting conditioned response (CR) such as an eyeblink [58]. Traditionally, it is considered that fear and eyeblink conditioning are unaffected in patients with hippocampal damage [59, 60]. So far, there are no studies with TGA patients assessing these types of classical conditioning, but more complex conditioning paradigms, as trace conditioning and fear conditioning, seem to be affected in TGA population. This contradictory result will

The perceptual representation system [47] facilitates word and object identification identification based on form and structure information , but not considering meaning or associative properties. It is pre-semantic, implicit, not hippocampal dependent, and Usually it is spared in amnesia. Priming is a phenomenon dependent of this system. It implies a behavioral change that is reflected in speed or accuracy change with stimulus processed following prior exposure [61]. For example, the word "plane" will produce faster response when it is preceded by the word "rain," because both words are auditorily similar, comparing when it is preceded by

There is some empirical evidence that suggests that PRS remains preserved during TGA episodes. Kapur et al. [62] showed that perceptual priming was spared during TGA through a fragmented figure completion task with visually degraded drawings. And even 1 week after the amnestic episode, the patient continued to show priming effect with the figures studied during the TGA episode compared with new figures. This result has been confirmed using different learning materials as fragmented numbers [13] and verbal material with a word

Semantic memory refers to the acquisition, retention, and use of general knowledge (facts, concepts, vocabulary, and knowledge about the world and the individuals). It is declarative, independent of contextual information, and it is usually not

During the TGA, language is intact. According to Caplan [17], patients show spontaneous speech and normal vocabulary, and they do not present aphasic errors.

*3.3.1 Retrieval of semantic knowledge acquired before the TGA*

*Neurological and Mental Disorders*

dependent memory [46].

of hippocampal neurons.

**3. Memory systems and TGA**

has helped to classify the different memory systems.

and explicit memory that is conscious and intentional.

have shown that emotional and behavioral stresses impair long-term potentiation and enhance long-term depression in CA1 neurons, disturbing the hippocampus-

In conclusion, the causal mechanisms underlying hippocampal perturbations of TGA remain unclear, but it seems probable that TGA is related with metabolic stress

Traditionally, a memory system perspective has been used to describe which processes are affected and preserved during amnesia. From this perspective, memory is considered as a not unitary entity, with relatively independent but interacting systems that process different types of information, which have different cognitive rules and that are implemented in specific cerebral networks [47]. In order to define this systems, animal and human, behavioral, clinical, neuropsychological, and neuroimaging studies have been used [48–50]. The combination of these findings

In order to describe the complexity of memory, initially binary models were suggested. Cohen and Squire [51] proposed that long-term memory could be subdivided between declarative memory, which is representational, can be verbalized, and is severely impaired during amnesia, and procedural memory, which is expressed through action, is independent from conscious awareness, and is preserved during amnesia. On the other hand, Graf et al. [52] suggested that long-term memory is divided into implicit memory that is acquired and used unconsciously

Later, a more complex model was proposed, which is considered a classical classification model of memory systems [47, 53]. This model includes the following memory systems: episodic memory, working memory, semantic memory, priming, and procedural memory. This proposal assumes that there is a continuum between explicit/implicit and declarative/procedural dimensions through different memory systems. In the following sections, each system will be defined, and the impairments and preservation pattern associated with the TGA will be

Procedural memory is the system that allows no-conscious acquisition, maintenance, and the use of motor and cognitive skills. It is characterized by gradual or progressive acquisition, which typically results in increased speed or accuracy with repetition. It includes heterogeneous set of subsystems: motor and cognitive abilities, habits, conditioning, and nonassociative learning. It is implicit and non-declarative, it is not hippocampal dependent, and it is spared in

During the TGA episode, patients are able to perform complex but automatized activities learnt before the attack. For example, they are able to play the organ [54], conduct a talk [17], cook [24], drive a car [55], or conduct a concert [56]. These and similar activities, which are usually quite complex, when becoming routine procedures no longer need the involvement of the hippocampus. Thus, during the TGA

procedural memories acquired before the TGA tend to be preserved [56].

**192**

described.

amnesia [53].

**3.1 Procedural memory**

*3.1.1 Skills acquired before the TGA*

#### *3.1.2 Acquisition of new procedural skills during the TGA*

In addition, the ability to learn new procedural skills remains preserved as well during TGA episode. For example, Eustache et al. [40] showed that TGA patients are able to acquire mirror-reading skill at the same learning speed as the control group.

Another example of implicit learning phenomenon is the mere exposure effect, which is defined as preference enhancement to previously exposed stimuli [57]. Mere exposure effect is preserved in TGA patients during the amnesic episode, showing enhanced preference for previously exposed faces, in spite of the severe anterograde memory loss [27].

Classical conditioning is another subtype of procedural memory that is based on associative learning. In classical conditioning, repeated pairings of a neutral conditioned stimulus (CS), such as a tone, and an unconditioned stimulus (US) such as an air-puff to the eye result in the CS alone, eliciting conditioned response (CR) such as an eyeblink [58]. Traditionally, it is considered that fear and eyeblink conditioning are unaffected in patients with hippocampal damage [59, 60]. So far, there are no studies with TGA patients assessing these types of classical conditioning, but more complex conditioning paradigms, as trace conditioning and fear conditioning, seem to be affected in TGA population. This contradictory result will be described in Section 3.

#### **3.2 Perceptual representation system**

The perceptual representation system [47] facilitates word and object identification identification based on form and structure information , but not considering meaning or associative properties. It is pre-semantic, implicit, not hippocampal dependent, and Usually it is spared in amnesia. Priming is a phenomenon dependent of this system. It implies a behavioral change that is reflected in speed or accuracy change with stimulus processed following prior exposure [61]. For example, the word "plane" will produce faster response when it is preceded by the word "rain," because both words are auditorily similar, comparing when it is preceded by the word "frog."

There is some empirical evidence that suggests that PRS remains preserved during TGA episodes. Kapur et al. [62] showed that perceptual priming was spared during TGA through a fragmented figure completion task with visually degraded drawings. And even 1 week after the amnestic episode, the patient continued to show priming effect with the figures studied during the TGA episode compared with new figures. This result has been confirmed using different learning materials as fragmented numbers [13] and verbal material with a word completion task [40].

#### **3.3 Semantic memory**

Semantic memory refers to the acquisition, retention, and use of general knowledge (facts, concepts, vocabulary, and knowledge about the world and the individuals). It is declarative, independent of contextual information, and it is usually not affected in amnesia [63].

#### *3.3.1 Retrieval of semantic knowledge acquired before the TGA*

During the TGA, language is intact. According to Caplan [17], patients show spontaneous speech and normal vocabulary, and they do not present aphasic errors. They maintain the ability to repeat oral language, to read, and to write. They can describe not present objects, geographical details, and familiar places using their semantic knowledge. Patients with TGA are able to recognize and name objects and colors [64] and to point at drawings in response to words [65]. In addition, nonverbal semantic knowledge, assessed with a task that requires matching conceptually related figures, is also preserved [65].

Regarding verbal fluency tasks, in which participants have to produce as many words as possible from a category in a given time, there are contradictory results. While in some studies [40, 45, 66–68], TGA patients presented lower production of category examples than the control group, both with words within a semantic category (category fluency) and with words starting with a given letter (letter fluency); in other investigations [64, 65, 69, 70] no significant differences were found between TGA patients and the control group, although the former produced more perseverations.

Regarding knowledge about the world, memory for past public events and famous people is impaired during TGA [62], especially for events and people from recent decades [64]. TGA patients are able to differentiate between real events from fictional events, probably based on their implicit knowledge. But their ability to localize these events in time, primarily those from the closest decades to the amnesic episode, is impaired [71, 72]. Recognition of famous people faces seems to be preserved in some cases [64, 71], but there is some contradictory data [72], especially regarding faces linked to recent experiences.

#### *3.3.2 Acquisition of new semantic knowledge during the TGA*

It is not clear if TGA patients are able to learn new semantic memory during amnesic episode. It is important to address this question. Interestingly, there is evidence of preserved semantic priming during TGA [73, 74]. TGA patients showed semantic priming during TGA episode, and this effect persisted for 1 day [73]. But there is no data about the ability of TGA patients to acquire semantic facts. Previous research has shown that the left hippocampus is involved in successful incidental acquisition of new facts about the world [75].

Furthermore, there is evidence of patients with medial temporal lobe lesions that are impaired to learn new semantic knowledge [76]. Thus, it would be interesting to study this issue with TGA patients. Based on permanent amnesia impairment pattern, new semantic knowledge acquisition is expected to be affected during TGA.

#### **3.4 Working memory**

Short-term memory implies the conscious retention for information over a few seconds, often through active rehearsal. When the information held in short-term memory is manipulated or another task is performed, this is often referred to as working memory [77].

Based on previous research, TGA patients have preserved capacity to maintain activated a limited amount of information for a brief period of time. This has been addressed using digit span task [13, 71, 78–80], immediate memory for rhythms [81, 82], memory for spatial positions measured with the Corsi block-tapping task [45, 70, 71, 78, 80], and immediate recall for letters and objects [81]. Regarding working memory during TGA, there are no conclusive results, probably due to the diversity of required processes and the variability of complexity level through different tasks. **Table 1** summarizes the data.

**195**

*Neurocognitive Perspective of Transient Global Amnesia DOI: http://dx.doi.org/10.5772/intechopen.88810*

Stroop task (inhibition to avoid reading and focus on the

Trail making test (connect fastest possible numbers placed

Backward memory span (recall stimuli in reverse order of

Updating task (listen to auditory-presented letters, and decide if each letter that is added matches one of the

Brown-Peterson's experimental paradigm (retain three consonant letters while performing a distractor task)

Raven's progressive matrices (nonverbal abstract reasoning: to find a missing element to complete a pattern)

**3.5 Episodic memory**

**Table 1.**

ink color)

randomly in a paper sheet)

the presentation)

previous three letters)

dependent, and severely damaged in amnesia [63].

(environmental sounds and speech) [84].

complex geometric figures [40, 64, 78, 85, 86].

being impaired for the patients [27].

*3.5.1 Acquisition of new episodic information during the TGA*

*Summary of studies assessing working memory in TGA patients with different tasks.*

Episodic memory encodes, stores, and recovers memories about past events in a spatio-temporal context. This memory allows to reexperience the past episodes as in a mental "time travel." The episodic system is declarative, explicit, hippocampus

**Task During TGA References**

Card sorting task (flexibility to change matching criteria) Impaired. Only one

Preserved [64, 65, 68, 70]

Preserved [65, 68]

Preserved [70, 71] Impaired [78, 80, 83]

Preserved [70]

Preserved [65]

[13]

[70]

classification criteria of the six possible

Deficit with 3- and 6- second delay intervals

One of the most characteristic features of TGA is the deficit to form lasting memories of new episodic information. This impairment affects the acquisition of any kind of information: visual (figures and words), tactile, olfactory, or auditory

the ability to reproduce previously presented material, is severely impaired, using visually presented words [40, 66, 67, 70, 78], auditory-presented words [27, 64, 85], semantically unrelated word pairs [72, 86], prose passages [40, 62, 72, 81, 86], or

Regarding cue-recall, the ability to retrieve information with a recovery cue that guides searching processes, there are no conclusive data. Some patients obtain preserved cue-recall scores, and other patients show significantly lower performance than the control group [27, 69, 70, 81]. And it seems that is not related with the type of cueing methods but with the patient, since contradictory outputs have been found using the same method. In a study with a bigger sample, there was a significant difference between TGA patients and the control group in cue-recall,

Regarding recognition, the ability to recognize previously presented stimuli, is impaired in patients with TGA, both with words and drawings [41, 66, 69, 80, 85]. Recognition is usually subdivided into two component processes: recollection and familiarity, frequently measured with the "remember/know" (R/K) paradigm.

Different laboratory tests have been used to measure episodic memory. Free recall,


**Table 1.**

*Neurological and Mental Disorders*

related figures, is also preserved [65].

perseverations.

during TGA.

**3.4 Working memory**

working memory [77].

They maintain the ability to repeat oral language, to read, and to write. They can describe not present objects, geographical details, and familiar places using their semantic knowledge. Patients with TGA are able to recognize and name objects and colors [64] and to point at drawings in response to words [65]. In addition, nonverbal semantic knowledge, assessed with a task that requires matching conceptually

Regarding verbal fluency tasks, in which participants have to produce as many words as possible from a category in a given time, there are contradictory results. While in some studies [40, 45, 66–68], TGA patients presented lower production of category examples than the control group, both with words within a semantic category (category fluency) and with words starting with a given letter (letter fluency); in other investigations [64, 65, 69, 70] no significant differences were found between TGA patients and the control group, although the former produced more

Regarding knowledge about the world, memory for past public events and famous people is impaired during TGA [62], especially for events and people from recent decades [64]. TGA patients are able to differentiate between real events from fictional events, probably based on their implicit knowledge. But their ability to localize these events in time, primarily those from the closest decades to the amnesic episode, is impaired [71, 72]. Recognition of famous people faces seems to be preserved in some cases [64, 71], but there is some contradictory data [72],

It is not clear if TGA patients are able to learn new semantic memory during amnesic episode. It is important to address this question. Interestingly, there is evidence of preserved semantic priming during TGA [73, 74]. TGA patients showed semantic priming during TGA episode, and this effect persisted for 1 day [73]. But there is no data about the ability of TGA patients to acquire semantic facts. Previous research has shown that the left hippocampus is involved in successful incidental

Furthermore, there is evidence of patients with medial temporal lobe lesions

Short-term memory implies the conscious retention for information over a few seconds, often through active rehearsal. When the information held in short-term memory is manipulated or another task is performed, this is often referred to as

Based on previous research, TGA patients have preserved capacity to maintain activated a limited amount of information for a brief period of time. This has been addressed using digit span task [13, 71, 78–80], immediate memory for rhythms [81, 82], memory for spatial positions measured with the Corsi block-tapping task [45, 70, 71, 78, 80], and immediate recall for letters and objects [81]. Regarding working memory during TGA, there are no conclusive results, probably due to the diversity of required processes and the variability of complexity level through

that are impaired to learn new semantic knowledge [76]. Thus, it would be interesting to study this issue with TGA patients. Based on permanent amnesia impairment pattern, new semantic knowledge acquisition is expected to be affected

especially regarding faces linked to recent experiences.

acquisition of new facts about the world [75].

different tasks. **Table 1** summarizes the data.

*3.3.2 Acquisition of new semantic knowledge during the TGA*

**194**

*Summary of studies assessing working memory in TGA patients with different tasks.*

#### **3.5 Episodic memory**

Episodic memory encodes, stores, and recovers memories about past events in a spatio-temporal context. This memory allows to reexperience the past episodes as in a mental "time travel." The episodic system is declarative, explicit, hippocampus dependent, and severely damaged in amnesia [63].

#### *3.5.1 Acquisition of new episodic information during the TGA*

One of the most characteristic features of TGA is the deficit to form lasting memories of new episodic information. This impairment affects the acquisition of any kind of information: visual (figures and words), tactile, olfactory, or auditory (environmental sounds and speech) [84].

Different laboratory tests have been used to measure episodic memory. Free recall, the ability to reproduce previously presented material, is severely impaired, using visually presented words [40, 66, 67, 70, 78], auditory-presented words [27, 64, 85], semantically unrelated word pairs [72, 86], prose passages [40, 62, 72, 81, 86], or complex geometric figures [40, 64, 78, 85, 86].

Regarding cue-recall, the ability to retrieve information with a recovery cue that guides searching processes, there are no conclusive data. Some patients obtain preserved cue-recall scores, and other patients show significantly lower performance than the control group [27, 69, 70, 81]. And it seems that is not related with the type of cueing methods but with the patient, since contradictory outputs have been found using the same method. In a study with a bigger sample, there was a significant difference between TGA patients and the control group in cue-recall, being impaired for the patients [27].

Regarding recognition, the ability to recognize previously presented stimuli, is impaired in patients with TGA, both with words and drawings [41, 66, 69, 80, 85]. Recognition is usually subdivided into two component processes: recollection and familiarity, frequently measured with the "remember/know" (R/K) paradigm. Recollection implies the retrieval of contextual details of the previous event, and familiarity is based on the feeling that the event was previously experienced but without details or context [87]. Recollection has been traditionally linked with episodic memory and hippocampal function, while familiarity is related with semantic memory and it is independent from the hippocampus [88]. Impaired R/K response pattern has been shown in TGA patients [70, 89], with usually lower recollection scores in TGA patients than in controls, while no significant difference in familiarity scores between TGA and controls [80].

#### **3.6 Autobiographical memory**

Autobiographical memory is a uniquely human system that integrates memories of past experiences into a life narrative [90], and it allows to mentally travel in time [63]. There are two components of autobiographical memory: episodic and semantic autobiographical memory. Episodic autobiographical memory refers to the memories of our personal past, and it is usually assessed with interviews that cover events from childhood until hours before the amnesic episode. Semantic autobiographical memory refers to the recollection of personal facts and general self-knowledge independent of a specific time and space [91]. This division between episodic and semantic components of autobiographical memory is based on dissociations found with amnesic patients as KC [92], which shows an episodic autobiographical memory disturbed while the semantic component is preserved.

#### *3.6.1 Acquisition of new autobiographical information during TGA*

TGA patients are not able to create autobiographical memories during the TGA episode showing a severely anterograde amnesia for this self-related information. When recovering from the TGA episode, patients show a memory gap of those hours that is never recovered.

#### *3.6.2 Retrieval of autobiographical memories acquired before the TGA*

Neuropsychological studies of TGA patients have shown that they have problems to remember their past, even though this deficit is milder than anterograde deficit. During TGA, episodic autobiographical memories from different periods of life are affected, showing deficit of details, absence of spatial and temporal context, and even sometimes confusion between memories [67, 69, 72, 89]. This retrograde amnesia usually is temporally graded [22], and it follows Ribot's Law [93], which implies deeper impairment of the closest memories compared with remote memories.

In contrast, semantic autobiographical memory is preserved. TGA patients usually recall personal information such as age, place of birth, past addresses, phone number, names of teachers, and educational and professional history [17, 94].

#### **3.7 Conclusion about memory systems and TGA**

This section has shown the memory deficit pattern of TGA based on the classical memory systems perspective, which considers that the hippocampus is engaged in declarative and explicit memory but not in non-declarative and implicit memory. This perspective leads to some inconsistencies. For example, it seems that some types of classical conditioning as trace conditioning and fear conditioning are affected in TGA patients, but based on the memory systems perspective, they should be preserved. Furthermore, working memory should be preserved as well

**197**

*Neurocognitive Perspective of Transient Global Amnesia DOI: http://dx.doi.org/10.5772/intechopen.88810*

in TGA patients, but some complex working memory tasks seem to be affected. It is also important to point out that there is not much understanding of the TGA patients' ability to acquire very complex stimuli as people's faces or complex semantic knowledge during the TGA. In the following section, in order to try to resolve

Since the famous case of the HM patient, the hippocampus has been considered a key structure for memory. HMs' medial temporal lobe (including hippocampi) was removed in order to try to control intractable seizures [95]. This produced him a profound amnesia specially to acquire new memories. Since that time, extensive research has been conducted in order to understand the hippocampus involvement

As it was mentioned before, there is a temporary perturbation of the hippocampal function during the TGA. Therefore, this section reviews the theories about the hippocampal function and its consequences to interpret the amnesic pattern of TGA patients. These theories are organized based on the nature of the memory processes

There are three main processes involved in human memory: encoding, which allows converting perceived information into a more permanent form; consolidation, which stabilizes a memory trace after its initial acquisition; and retrieval, which involves re-accessing events or information from the past [96]. There is a general agreement that episodic memories depend on the hippocampus during the encoding of new memories [95]. But the involvement of the hippocampus on

The Standard Model of Consolidation considers that episodic and semantic memories become less dependent on the hippocampus until they are completely independent [97]. On the contrary, multi-trace theory defends that the hippocampus is crucial for acquisition of both, episodic and semantic memories. But the recollection of episodic memories remains dependent on the hippocampus in order to retrieve contextual and detailed memories, whereas semantic memories become

There is a historic debate whether the hippocampus is required to retrieve remote autobiographical memories [99]. Considering this type of memories, two patterns emerge from the literature about patients with medial temporal lobe damage: complete autobiographical memory loss across all time points, recent and remote [100, 101], and memory loss with a temporal gradient, with recent memories lost but remote memories preserved [102]. These patterns could be reflecting at least two different explanations: that autobiographical memories become less detailed and more semanticized over time and thus less dependent of the hippocampus, which could explain the apparent preservation of remote autobiographical memories in some patients [98], or that the brain damage extension is different between patients and those with widespread damage are the ones showing remote

In fMRI studies, it has been shown that the hippocampus is associated with retrieving autobiographical memories, which are detailed and vivid, anytime that they are recalled, regardless of age of the memory [75, 104]. And studies using multivoxel pattern analysis (MVPA) has shown that more recent memories engage

these inconsistencies, new research about the hippocampus is analyzed.

**4. New insights from the hippocampal function research**

in learning and memory and in other cognitive domains.

involved and the type of information that is processed.

retrieving remote memories is controversial.

independent from the hippocampus [98].

autobiographical memories impaired [103].

**4.1 Memory processes**

*Neurological and Mental Disorders*

ity scores between TGA and controls [80].

**3.6 Autobiographical memory**

hours that is never recovered.

Recollection implies the retrieval of contextual details of the previous event, and familiarity is based on the feeling that the event was previously experienced but without details or context [87]. Recollection has been traditionally linked with episodic memory and hippocampal function, while familiarity is related with semantic memory and it is independent from the hippocampus [88]. Impaired R/K response pattern has been shown in TGA patients [70, 89], with usually lower recollection scores in TGA patients than in controls, while no significant difference in familiar-

Autobiographical memory is a uniquely human system that integrates memories

TGA patients are not able to create autobiographical memories during the TGA episode showing a severely anterograde amnesia for this self-related information. When recovering from the TGA episode, patients show a memory gap of those

Neuropsychological studies of TGA patients have shown that they have problems to remember their past, even though this deficit is milder than anterograde deficit. During TGA, episodic autobiographical memories from different periods of life are affected, showing deficit of details, absence of spatial and temporal context, and even sometimes confusion between memories [67, 69, 72, 89]. This retrograde amnesia usually is temporally graded [22], and it follows Ribot's Law [93], which implies deeper impairment of the closest memories compared with remote

In contrast, semantic autobiographical memory is preserved. TGA patients usually recall personal information such as age, place of birth, past addresses, phone number, names of teachers, and educational and professional history [17, 94].

This section has shown the memory deficit pattern of TGA based on the classical memory systems perspective, which considers that the hippocampus is engaged in declarative and explicit memory but not in non-declarative and implicit memory. This perspective leads to some inconsistencies. For example, it seems that some types of classical conditioning as trace conditioning and fear conditioning are affected in TGA patients, but based on the memory systems perspective, they should be preserved. Furthermore, working memory should be preserved as well

of past experiences into a life narrative [90], and it allows to mentally travel in time [63]. There are two components of autobiographical memory: episodic and semantic autobiographical memory. Episodic autobiographical memory refers to the memories of our personal past, and it is usually assessed with interviews that cover events from childhood until hours before the amnesic episode. Semantic autobiographical memory refers to the recollection of personal facts and general self-knowledge independent of a specific time and space [91]. This division between episodic and semantic components of autobiographical memory is based on dissociations found with amnesic patients as KC [92], which shows an episodic autobiographical memory disturbed while the semantic component is preserved.

*3.6.1 Acquisition of new autobiographical information during TGA*

*3.6.2 Retrieval of autobiographical memories acquired before the TGA*

**3.7 Conclusion about memory systems and TGA**

**196**

memories.

in TGA patients, but some complex working memory tasks seem to be affected. It is also important to point out that there is not much understanding of the TGA patients' ability to acquire very complex stimuli as people's faces or complex semantic knowledge during the TGA. In the following section, in order to try to resolve these inconsistencies, new research about the hippocampus is analyzed.

#### **4. New insights from the hippocampal function research**

Since the famous case of the HM patient, the hippocampus has been considered a key structure for memory. HMs' medial temporal lobe (including hippocampi) was removed in order to try to control intractable seizures [95]. This produced him a profound amnesia specially to acquire new memories. Since that time, extensive research has been conducted in order to understand the hippocampus involvement in learning and memory and in other cognitive domains.

As it was mentioned before, there is a temporary perturbation of the hippocampal function during the TGA. Therefore, this section reviews the theories about the hippocampal function and its consequences to interpret the amnesic pattern of TGA patients. These theories are organized based on the nature of the memory processes involved and the type of information that is processed.

#### **4.1 Memory processes**

There are three main processes involved in human memory: encoding, which allows converting perceived information into a more permanent form; consolidation, which stabilizes a memory trace after its initial acquisition; and retrieval, which involves re-accessing events or information from the past [96]. There is a general agreement that episodic memories depend on the hippocampus during the encoding of new memories [95]. But the involvement of the hippocampus on retrieving remote memories is controversial.

The Standard Model of Consolidation considers that episodic and semantic memories become less dependent on the hippocampus until they are completely independent [97]. On the contrary, multi-trace theory defends that the hippocampus is crucial for acquisition of both, episodic and semantic memories. But the recollection of episodic memories remains dependent on the hippocampus in order to retrieve contextual and detailed memories, whereas semantic memories become independent from the hippocampus [98].

There is a historic debate whether the hippocampus is required to retrieve remote autobiographical memories [99]. Considering this type of memories, two patterns emerge from the literature about patients with medial temporal lobe damage: complete autobiographical memory loss across all time points, recent and remote [100, 101], and memory loss with a temporal gradient, with recent memories lost but remote memories preserved [102]. These patterns could be reflecting at least two different explanations: that autobiographical memories become less detailed and more semanticized over time and thus less dependent of the hippocampus, which could explain the apparent preservation of remote autobiographical memories in some patients [98], or that the brain damage extension is different between patients and those with widespread damage are the ones showing remote autobiographical memories impaired [103].

In fMRI studies, it has been shown that the hippocampus is associated with retrieving autobiographical memories, which are detailed and vivid, anytime that they are recalled, regardless of age of the memory [75, 104]. And studies using multivoxel pattern analysis (MVPA) has shown that more recent memories engage

#### *Neurological and Mental Disorders*

the anterior hippocampus but the posterior hippocampus is especially essential for remote memories [105] . This shows that there is a temporal gradient representation within the hippocampus itself. Thus, the neuropsychological loss pattern of each patient may depend on the location and extent of the damage within the hippocampus.

In TGA patients, the autobiographic memory loss has two different patterns: a continuous pattern, when memories from a limited period are affected, and an irregular pattern, when memory loss is selective without a clear time interval [78, 86, 105]. This could be related with the temporal gradient shown within the hippocampus itself [105]. But in most cases, TGA patients follow Ribot's Law [93], so that recent memories are more likely to be lost than more remote memories. This is coherent with the pattern shown in patient with permanent hippocampal damage (e.g., [102]).

#### **4.2 Type of processed information**

#### *4.2.1 Navigation and spatial representation*

Spatial information is a type of information that has been proposed to be processed by the hippocampus. Animal studies have shown that place cells in the hippocampus encode location while moving in the environment, and these cells fire when a specific place field is entered, irrespective of where the animal is looking [106]. Thus, the hippocampus provides an internal space representation or cognitive map of the environment that is allocentric (world-centered) and not egocentric (self-centered) [107]. As it seems that the hippocampus is a relevant structure for both, episodic memory and spatial representation, it has been proposed that the spatial representations of the hippocampus could support spatial context to the episodic memories [108].

fMRI studies with humans support the idea that the hippocampus is engaged when mentally or virtually navigating an environment [109]. Furthermore, studies with permanent amnesic patients show that hippocampal damage impairs the spatial learning of new environments [101], but it is not essential to navigate in familiar places. In the same direction, TGA patients are able to return to familiar places or to drive in well-learnt routes [55]. This is coherent with the diminished hippocampal activation when navigating in familiar environment [110].

However, a further question important to address is if TGA patients are able to learn to navigate in a new environment while they are under the amnesic episode. Considering the hippocampus involvement in both, acquisition of new explicit knowledge and representation of space, an impaired performance is expected.

#### *4.2.2 Temporal representation*

Another type of knowledge that is related with the hippocampus is temporal information. There are some cell ensembles in the hippocampus, especially in the CA1 area, which fire when an animal is at a particular moment in a temporally structured experience. Firing patterns of these hippocampal neurons change gradually over time representing the flow of time in an experience [111]. Literature about patients with permanent temporal lobe amnesia shows that they are able to arrange information into a sequential narrative and they seem to understand the concept of time [112]. As we mentioned before, temporal orientation is severely affected during TGA [14], and they show an absence of temporal details when trying to remember their episodic autobiographical memories [67, 69, 72, 89]. But it would be interesting to study in more detail the concept of

**199**

ity of the associations.

*Neurocognitive Perspective of Transient Global Amnesia DOI: http://dx.doi.org/10.5772/intechopen.88810*

sense of time [113].

situations [118].

*4.2.3 Relational representation*

with individual items or events [67, 89].

well, but this issue should be studied.

time in TGA patients, including the representation of the duration of an event, the coding of temporal order of the elements in an episode, and the subjective

The relational memory theory assumes that the hippocampus' main function is to represent associations between different elements in order to bind together multiple inputs into a single representation [114, 115]. In this sense, hippocampus may represent bindings between items (e.g., who and what) and context (e.g., where and when) [116, 117]. Furthermore, the hippocampus allows to recall these flexible relational representations and to use that information for inference in novel

Regarding relational memory in TGA patients, two different types of contextual details have been studied: the recall of spatial information about the learning session (e.g., if words are presented on the top or bottom of the screen) and temporal information of specific items (e.g., if words belong to a first or second word list). TGA patients were very impaired remembering spatiotemporal details associated

Another insight from studies in patients with permanent hippocampal damage about relational memory is that these patients are able to recognize associations between items of the same domain (e.g., word-word), but they have problems to recognize associations between items of different kind (e.g., word-face) [119, 120]. Thus, when the task requires increased relational complexity, it is more dependent on the hippocampus and specially affected in patients with hippocampal damage. Thus, TGA patients may be impaired in across-domain association recognition as

A further example of hippocampal involvement in complex processing is scene reconstruction. It has been proposed that the main function of the hippocampus is scene reconstruction [121], which may be considered as a special case of relational memory theory. Scene processing requires combining individual features across domains in a complex and coherent representation of the world. Scene components need to be integrated from modality-specific representation into a spatially coherent representation [108]. It has been shown that scene recognition is impaired in patients with medial temporal lobe damage [118, 119], and even though it has not

been properly studied, it may be impaired in TGA patients as well.

There are additional examples about the hippocampal contribution when relational complexity increases, both in conditioning and in working memory. As it has been mentioned before, there is no hippocampus involvement in classical conditioning, but trace conditioning, which occurs when there is a time interval between offset of the conditioned stimulus and delivery of the unconditioned stimulus, requires hippocampal functioning [122]. Thus, the processing of a temporal contiguity delay in associative learning adds more complexity and requires the hippocampus. It would be interesting to study this type of conditioning with TGA patients. Contextual fear conditioning is another example of classical conditioning paradigm that requires complex associations and hippocampus involvement. This conditioning involves placing the animal in a novel environment, providing an aversive stimulus. When the animal is returned to the same environment, generally will recover the association between environment and the aversive stimulus and it will activate fear response (freezing response). TGA patients showed contextual fear conditioning impairment compared with the control group [123], which reflects the relationship between hippocampal functioning and relational complextime in TGA patients, including the representation of the duration of an event, the coding of temporal order of the elements in an episode, and the subjective sense of time [113].

#### *4.2.3 Relational representation*

*Neurological and Mental Disorders*

hippocampus.

damage (e.g., [102]).

episodic memories [108].

*4.2.2 Temporal representation*

**4.2 Type of processed information**

*4.2.1 Navigation and spatial representation*

the anterior hippocampus but the posterior hippocampus is especially essential for remote memories [105] . This shows that there is a temporal gradient representation within the hippocampus itself. Thus, the neuropsychological loss pattern of each patient may depend on the location and extent of the damage within the

In TGA patients, the autobiographic memory loss has two different patterns: a continuous pattern, when memories from a limited period are affected, and an irregular pattern, when memory loss is selective without a clear time interval [78, 86, 105]. This could be related with the temporal gradient shown within the hippocampus itself [105]. But in most cases, TGA patients follow Ribot's Law [93], so that recent memories are more likely to be lost than more remote memories. This is coherent with the pattern shown in patient with permanent hippocampal

Spatial information is a type of information that has been proposed to be processed by the hippocampus. Animal studies have shown that place cells in the hippocampus encode location while moving in the environment, and these cells fire when a specific place field is entered, irrespective of where the animal is looking [106]. Thus, the hippocampus provides an internal space representation or cognitive map of the environment that is allocentric (world-centered) and not egocentric (self-centered) [107]. As it seems that the hippocampus is a relevant structure for both, episodic memory and spatial representation, it has been proposed that the spatial representations of the hippocampus could support spatial context to the

fMRI studies with humans support the idea that the hippocampus is engaged when mentally or virtually navigating an environment [109]. Furthermore, studies with permanent amnesic patients show that hippocampal damage impairs the spatial learning of new environments [101], but it is not essential to navigate in familiar places. In the same direction, TGA patients are able to return to familiar places or to drive in well-learnt routes [55]. This is coherent with the diminished hippocampal

However, a further question important to address is if TGA patients are able to learn to navigate in a new environment while they are under the amnesic episode. Considering the hippocampus involvement in both, acquisition of new explicit knowledge and representation of space, an impaired performance is expected.

Another type of knowledge that is related with the hippocampus is temporal information. There are some cell ensembles in the hippocampus, especially in the CA1 area, which fire when an animal is at a particular moment in a temporally structured experience. Firing patterns of these hippocampal neurons change gradually over time representing the flow of time in an experience [111]. Literature about patients with permanent temporal lobe amnesia shows that they are able to arrange information into a sequential narrative and they seem to understand the concept of time [112]. As we mentioned before, temporal orientation is severely affected during TGA [14], and they show an absence of temporal details when trying to remember their episodic autobiographical memories [67, 69, 72, 89]. But it would be interesting to study in more detail the concept of

activation when navigating in familiar environment [110].

**198**

The relational memory theory assumes that the hippocampus' main function is to represent associations between different elements in order to bind together multiple inputs into a single representation [114, 115]. In this sense, hippocampus may represent bindings between items (e.g., who and what) and context (e.g., where and when) [116, 117]. Furthermore, the hippocampus allows to recall these flexible relational representations and to use that information for inference in novel situations [118].

Regarding relational memory in TGA patients, two different types of contextual details have been studied: the recall of spatial information about the learning session (e.g., if words are presented on the top or bottom of the screen) and temporal information of specific items (e.g., if words belong to a first or second word list). TGA patients were very impaired remembering spatiotemporal details associated with individual items or events [67, 89].

Another insight from studies in patients with permanent hippocampal damage about relational memory is that these patients are able to recognize associations between items of the same domain (e.g., word-word), but they have problems to recognize associations between items of different kind (e.g., word-face) [119, 120]. Thus, when the task requires increased relational complexity, it is more dependent on the hippocampus and specially affected in patients with hippocampal damage. Thus, TGA patients may be impaired in across-domain association recognition as well, but this issue should be studied.

A further example of hippocampal involvement in complex processing is scene reconstruction. It has been proposed that the main function of the hippocampus is scene reconstruction [121], which may be considered as a special case of relational memory theory. Scene processing requires combining individual features across domains in a complex and coherent representation of the world. Scene components need to be integrated from modality-specific representation into a spatially coherent representation [108]. It has been shown that scene recognition is impaired in patients with medial temporal lobe damage [118, 119], and even though it has not been properly studied, it may be impaired in TGA patients as well.

There are additional examples about the hippocampal contribution when relational complexity increases, both in conditioning and in working memory. As it has been mentioned before, there is no hippocampus involvement in classical conditioning, but trace conditioning, which occurs when there is a time interval between offset of the conditioned stimulus and delivery of the unconditioned stimulus, requires hippocampal functioning [122]. Thus, the processing of a temporal contiguity delay in associative learning adds more complexity and requires the hippocampus. It would be interesting to study this type of conditioning with TGA patients. Contextual fear conditioning is another example of classical conditioning paradigm that requires complex associations and hippocampus involvement. This conditioning involves placing the animal in a novel environment, providing an aversive stimulus. When the animal is returned to the same environment, generally will recover the association between environment and the aversive stimulus and it will activate fear response (freezing response). TGA patients showed contextual fear conditioning impairment compared with the control group [123], which reflects the relationship between hippocampal functioning and relational complexity of the associations.

As it has been mentioned before, working memory has traditionally been considered as immune from hippocampal damage. But, it has been shown that when working memory task requires more complex stimuli or relational binding, then it shows to be affected when hippocampus is disturbed [108, 124]. This may partially explain the contradictory results of working memory in TGA that are considered in Section 2.

In order to account hippocampal sensitivity to complexity and precision, it has been proposed pattern separation as the underlying computational mechanism [99]. This pattern separation enables to differentiate with precision between items with overlapping features or relations [125]. It would be desirable to study this mechanism in TGA patients in order to understand deeply the deficit associated with this syndrome.

Thus, predictions from memory system model would expect that, for example, conditioning and working memory are immune to hippocampal damage and preserved during TGA. But a deeper analysis of the function of the hippocampus shows the hippocampal involvement, and its impairment in amnesia is related with the level of relational complexity of the processed information and with the computations needed in this processing.

#### *4.2.4 Future and imagination*

Traditionally, the hippocampus has been considered essential to retrieve memories from the past, but recent research suggests that it may also be related to envision and predict the future events and to imagine fictitious episodes [126]. It has been shown that the hippocampus and connected areas recombine elements of existing episodic memories to create new scenarios, and this allows creating a representation of the future and imagining new events [127]. Regarding the ability to imagine future events in patients with permanent hippocampal amnesia, usually they show problems answering questions about the future [128], and they show less richness and less integration of contextual details than the control group in imagining fictitious events or scenes [129, 130].

Research with TGA patients has shown that even though they can imagine past and future events, they provide fewer and less detailed events than the control group [131]. In another study, TGA patients showed prospective memory deficit, which involves remembering to perform an intended action at some point in the future [132], and this deficit was correlated with their retrograde impairment [68]. This probably reflects shared processes between remembering the past and projecting into the future.

In relation to future planning, mind-wandering is a form of spontaneous selfgenerated thinking independent from the current perceptual surrounding [133]. It has been shown that people with selective bilateral hippocampal damage are able to engage in mind-wandering as controls. However, their form and content of mindwandering are different, showing less flexible and scene-based content and more abstract and semanticized representation [134]. An open question to be addressed is mind-wandering and creative thinking in TGA patients.

#### **5. Conclusion**

The main goal of this chapter was to present a neurocognitive perspective of the deficits and preserved abilities of TGA. In order to carry out this goal, basic characteristics of TGA were analyzed, including diagnostic criteria, etiology, and differential diagnosis. Then, the deficit pattern of TGA was presented based on the

**201**

*Neurocognitive Perspective of Transient Global Amnesia DOI: http://dx.doi.org/10.5772/intechopen.88810*

that are not studied yet with TGA population.

The author declares no conflict of interest.

University of the Basque Country (UPV/EHU), San Sebastián, Spain

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: eugenia.marin@ehu.eus

provided the original work is properly cited.

sias and in TGA.

**Acknowledgements**

**Conflict of interest**

**Author details**

Eugenia Marin-Garcia

chapter.

classical memory systems model. This perspective assumes that declarative and explicit memory systems, as episodic and semantic memory, are severely affected during TGA. On the contrary, procedural and implicit memory systems, as procedural memory and perceptual representation system, and also working memory are preserved, while they are not dependent on hippocampal processing. The analysis

Afterward, in order to try to understand these inconsistencies and considering that TGA is associated with transitory perturbation of the hippocampal function, new research about the hippocampus and its cognitive mechanisms are analyzed. It seems that declarative/procedural and implicit/explicit dimensions are not decisive to be affected by hippocampus damage. Nevertheless, processes as associative or relational binding and pattern separation, which operate regardless of declarative level and conscious awareness, are especially sensitive to hippocampal impairment. Moreover, the complexity level of those processes seems to be a modulating factor that affects the impairment degree both in permanent hippocampal amne-

This new perspective focused on the hippocampal function has proportioned a better understanding of inconsistent results, and it has pointed out new questions

I am grateful to Yeray Mera for his help to prepare the References section of this

of this perspective leads to some contradictory or unresolved issues.

*Neurocognitive Perspective of Transient Global Amnesia DOI: http://dx.doi.org/10.5772/intechopen.88810*

*Neurological and Mental Disorders*

Section 2.

with this syndrome.

tations needed in this processing.

ing fictitious events or scenes [129, 130].

mind-wandering and creative thinking in TGA patients.

ing into the future.

**5. Conclusion**

*4.2.4 Future and imagination*

As it has been mentioned before, working memory has traditionally been considered as immune from hippocampal damage. But, it has been shown that when working memory task requires more complex stimuli or relational binding, then it shows to be affected when hippocampus is disturbed [108, 124]. This may partially explain the contradictory results of working memory in TGA that are considered in

In order to account hippocampal sensitivity to complexity and precision, it has been proposed pattern separation as the underlying computational mechanism [99]. This pattern separation enables to differentiate with precision between items with overlapping features or relations [125]. It would be desirable to study this mechanism in TGA patients in order to understand deeply the deficit associated

Thus, predictions from memory system model would expect that, for example,

conditioning and working memory are immune to hippocampal damage and preserved during TGA. But a deeper analysis of the function of the hippocampus shows the hippocampal involvement, and its impairment in amnesia is related with the level of relational complexity of the processed information and with the compu-

Traditionally, the hippocampus has been considered essential to retrieve memories from the past, but recent research suggests that it may also be related to envision and predict the future events and to imagine fictitious episodes [126]. It has been shown that the hippocampus and connected areas recombine elements of existing episodic memories to create new scenarios, and this allows creating a representation of the future and imagining new events [127]. Regarding the ability to imagine future events in patients with permanent hippocampal amnesia, usually they show problems answering questions about the future [128], and they show less richness and less integration of contextual details than the control group in imagin-

Research with TGA patients has shown that even though they can imagine past and future events, they provide fewer and less detailed events than the control group [131]. In another study, TGA patients showed prospective memory deficit, which involves remembering to perform an intended action at some point in the future [132], and this deficit was correlated with their retrograde impairment [68]. This probably reflects shared processes between remembering the past and project-

In relation to future planning, mind-wandering is a form of spontaneous selfgenerated thinking independent from the current perceptual surrounding [133]. It has been shown that people with selective bilateral hippocampal damage are able to engage in mind-wandering as controls. However, their form and content of mindwandering are different, showing less flexible and scene-based content and more abstract and semanticized representation [134]. An open question to be addressed is

The main goal of this chapter was to present a neurocognitive perspective of the deficits and preserved abilities of TGA. In order to carry out this goal, basic characteristics of TGA were analyzed, including diagnostic criteria, etiology, and differential diagnosis. Then, the deficit pattern of TGA was presented based on the

**200**

classical memory systems model. This perspective assumes that declarative and explicit memory systems, as episodic and semantic memory, are severely affected during TGA. On the contrary, procedural and implicit memory systems, as procedural memory and perceptual representation system, and also working memory are preserved, while they are not dependent on hippocampal processing. The analysis of this perspective leads to some contradictory or unresolved issues.

Afterward, in order to try to understand these inconsistencies and considering that TGA is associated with transitory perturbation of the hippocampal function, new research about the hippocampus and its cognitive mechanisms are analyzed. It seems that declarative/procedural and implicit/explicit dimensions are not decisive to be affected by hippocampus damage. Nevertheless, processes as associative or relational binding and pattern separation, which operate regardless of declarative level and conscious awareness, are especially sensitive to hippocampal impairment. Moreover, the complexity level of those processes seems to be a modulating factor that affects the impairment degree both in permanent hippocampal amnesias and in TGA.

This new perspective focused on the hippocampal function has proportioned a better understanding of inconsistent results, and it has pointed out new questions that are not studied yet with TGA population.

#### **Acknowledgements**

I am grateful to Yeray Mera for his help to prepare the References section of this chapter.

#### **Conflict of interest**

The author declares no conflict of interest.

#### **Author details**

Eugenia Marin-Garcia University of the Basque Country (UPV/EHU), San Sebastián, Spain

\*Address all correspondence to: eugenia.marin@ehu.eus

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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## *Edited by Kaneez Fatima Shad and Kamil Hakan Dogan*

Mental disorders can result from disruption of neuronal circuitry, damage to the neuronal and non-neuronal cells, altered circuitry in the different regions of the brain and any changes in the permeability of the blood brain barrier. Early identification of these impairments through investigative means could help to improve the outcome for many brain and behaviour disease states.The chapters in this book describe how these abnormalities can lead to neurological and mental diseases such as ADHD (Attention Deficit Hyperactivity Disorder), anxiety disorders, Alzheimer's disease and personality and eating disorders. Psycho-social traumas, especially during childhood, increase the incidence of amnesia and transient global amnesia, leading to the temporary inability to create new memories.Early detection of these disorders could benefit many complex diseases such as schizophrenia and depression.

Published in London, UK © 2020 IntechOpen © manjik / iStock

Neurological and Mental Disorders

Neurological

and Mental Disorders

*Edited by Kaneez Fatima Shad and Kamil Hakan Dogan*