**2. Emotions, aging, and dementia**

Although the emotions have been studied for many years, a unanimous definition of this concept has not yet been reached. Emotions are physical responses controlled by the brain that make it possible to survive hostile environments and ensure the procreation of the species [1]. Emotions are actions expressed in the face, voice, or specific behaviors that tend to maintain the homeostasis of the organism [2]. In other words, and following other authors, the emotions are regulatory processes of action that arise in response to a trigger stimulus or identifiable object and activate estimative processes of the significance of these stimuli in relation to the goal pursued, producing changes in response systems, and different moods. Each emotion depends on a different neural network and produces specific corporal configurations that can be recognized in others [3].

We can distinguish between two main types of emotions; primary and secondary [4]. Primary emotions are considered innate and depend on the limbic system, especially the amygdala and anterior cingulated cortex. They are not culturally determined, but rather universal with a biological origin. The secondary emotions arise when the feeling is experienced, that is, when there is awareness of the emotions; they allow us to make connections between the stimuli, the situation, and the primary emotions. Secondary emotions are composed of the combination of primary emotions refined by experience, and they can give rise to possible emotional pathologies such as anxiety and depression.

For quite some time, aging has been studied on the basis of losses and gains, focusing the research above all on the cognitive part of the individual; however, it is well known that the noncognitive symptoms are disturbing to the families and caregivers of patients with dementia, and they can also seriously affect the well-being of the patients [5].

Following this line of thought, there is evidence that with age, one loses cognitive capacity. For example, it is more difficult to focus one's attention, and the memory begins to fail. This situation becomes more evident in the case of pathological aging framed within the field of cognitive impairment and dementia. However, with regard to the emotions, it is not clear to what degree their processing is affected by age or what these changes are, with contradictory results found regarding the perception of basic emotions by patients with dementia. In some cases, these patients show worse recognition of their emotions, whereas in other cases, no differences are found between patients with dementia and a group of healthy older people [6].

With regard to emotional processing in aging, this topic has been studied from two different and seemingly contradictory perspectives: the socio-cognitive approach to the emotions proposed and developed by Carstensen [7] and the neuropsychological approach, which relates certain brain areas to the processing of information with emotional content.

Both approaches study the emotions in aging, but obtaining different conclusions about the changes that occur in emotional processing. On the one hand, the sociocognitive component focuses on what people think or feel, basically studying this component and suggesting that it does not decline with age and even improves [7]. On the other hand, the neuropsychological approach, interested basically in the processing of the emotional content of stimuli, argues that in both normal and pathological aging, there is a change in the identification of the negative emotions produced by a deficit in certain cerebral areas. Therefore, the consequences of the physiological changes stemming from aging are related to their effects on people's affective lives [8].

autobiographical memory, reminiscence, psychological and behavioral disorders, nonphar‐ macological interventions, etc. From these we selected those belonging to current and high-

Although the emotions have been studied for many years, a unanimous definition of this concept has not yet been reached. Emotions are physical responses controlled by the brain that make it possible to survive hostile environments and ensure the procreation of the species [1]. Emotions are actions expressed in the face, voice, or specific behaviors that tend to maintain the homeostasis of the organism [2]. In other words, and following other authors, the emotions are regulatory processes of action that arise in response to a trigger stimulus or identifiable object and activate estimative processes of the significance of these stimuli in relation to the goal pursued, producing changes in response systems, and different moods. Each emotion depends on a different neural network and produces specific corporal configurations that can

We can distinguish between two main types of emotions; primary and secondary [4]. Primary emotions are considered innate and depend on the limbic system, especially the amygdala and anterior cingulated cortex. They are not culturally determined, but rather universal with a biological origin. The secondary emotions arise when the feeling is experienced, that is, when there is awareness of the emotions; they allow us to make connections between the stimuli, the situation, and the primary emotions. Secondary emotions are composed of the combination of primary emotions refined by experience, and they can give rise to possible emotional

For quite some time, aging has been studied on the basis of losses and gains, focusing the research above all on the cognitive part of the individual; however, it is well known that the noncognitive symptoms are disturbing to the families and caregivers of patients with

Following this line of thought, there is evidence that with age, one loses cognitive capacity. For example, it is more difficult to focus one's attention, and the memory begins to fail. This situation becomes more evident in the case of pathological aging framed within the field of cognitive impairment and dementia. However, with regard to the emotions, it is not clear to what degree their processing is affected by age or what these changes are, with contradictory results found regarding the perception of basic emotions by patients with dementia. In some cases, these patients show worse recognition of their emotions, whereas in other cases, no differences are found between patients with dementia and a group of healthy older people [6].

With regard to emotional processing in aging, this topic has been studied from two different and seemingly contradictory perspectives: the socio-cognitive approach to the emotions proposed and developed by Carstensen [7] and the neuropsychological approach, which

relates certain brain areas to the processing of information with emotional content.

dementia, and they can also seriously affect the well-being of the patients [5].

impact journals.

450 Update on Dementia

**2. Emotions, aging, and dementia**

pathologies such as anxiety and depression.

be recognized in others [3].

It is well known that adequate emotional processing is fundamental for normal emotional development [9]. Alzheimer's disease (AD) has been widely studied with regard to the identification of emotions, given that the affective state declines progressively from the asymptomatic stage until the terminal phase. The patients no longer perceive their environ‐ ment with the same emotional base as before the disease. It is possible that this new affective state is progressive and can be detected early, through a basic analysis of the deficits in emotional information processing that will evolve into a greater degree of cognitive and emotional impairment as the disease progresses [10].

Regarding emotional perception, in AD the deficit in emotional recognition could be due to the progressive atrophy of the amygdala, the anterior temporal cortex, and the orbital frontal cortex [11]. Their study consists of presenting faces showing the basic emotions to a sample of mild AD patients, who have to identify and indicate the name of the emotions. They repeated the task 3 years later. Their conclusions were that the recognition of emotional expression was affected as the disease progressed, and that this impairment was related to the degeneration of the cortical structures involved.

Other studies [12–14] indicate that patients with AD have an impaired capacity to process the facial expressions of emotion, probably due to the characteristic cognitive deterioration associated with the disease, especially in the attention and memory processes of the amygdala [11] and other brain structures that modulate emotional processing [15].

Taking the emotional process into account, some studies have pointed out that the depressive disorder is associated with a greater risk of developing cognitive alterations in aging [16] especially in AD [17]. Considering this relationship, some researchers have examined the temporal relationship between depression and AD in order to understand whether depression is simply a prodromic symptom of the disease that precedes the appearance of cognitive deficits, or whether a history of depression could be an independent risk factor for the development of the disease. Moreover, depression can occur in 30/40% of patients with AD [18], and it affects the clinical evolution of the disease. Many depressed people ignore positive information and focus on memories that support negative emotions, thus impeding the maintenance and achievement of psychological well-being or life satisfaction, while worsening the conservation of their identity in the present and, therefore, their quality of life.

However, people with AD can feel diverse emotions, even though they generally do not remember what sparked them [19]. Therefore, the emotions remain in the individual and, therefore, can be worked with as a way to improve the emotional well-being of patients with AD.

One of the aspects most linked to emotional well-being is the feeling of identity. People who have AD have limited access to the autobiographical memories related to identity mainte‐ nance, self-knowledge, and self-image.

Along these lines, the autobiographical memory (AM) plays a fundamental role in the construction and conservation of personal identity [20]. It is indispensable for maintaining a sense of continuity and understanding the self throughout the life cycle. In addition, it contributes to the development of daily activities such as social relationships, decision making, or problem solving [21].

Memories related to personal events from the past are much more complex and emotional than nonautobiographical memories, and they also contain more intimate information related to the self [22, 23]. Thus, they are more likely to be kept in the memory than nonautobiographical memories, even in pathological aging.

Therefore, autobiographical memories are an essential aspect in the progression of AD because they allow the preservation of the identity, which will contribute to the development of positive emotions or emotional well-being.
