**3. Executive functions**

**Figure 2.** Overview of cellular process associated with executive functions.

**2.2. Stress and cerebral cortex**

14 Health and Academic Achievement

Studies in humans and in experimental animals have shown that psychological stressor can suppress or increase the immune response, depending on the length of the stress (acute or chronic). Both in acute and chronic stress, physical exercise induces increase in the production of IL6, IL-4, IL-10, IL-13, IL-17, and TNFα [12]. However, few studies have explored the variation of cytokines in individuals with physical activity; in the case of the IL-17, it has been determined that their serum levels are not altered by the effect of practicing vigorous physical activity (chronic stress) [13]. The real impact of stressor is associated with intensity and frequency.

The prefrontal cortex allows efficient connectivity between the circuits associated with emotions, memory, and planning. An example of this is the intricate relationship with neurons of the *locus coeruleus*, *substantia nigra pars compacta,* and ventral tegmental area, by neuromodulators such as norepinephrine and dopamine. Despite to neuroanatomical location and catecholaminergic nature of its afferents, the prefrontal cortex is highly sensitive to damage; for example, during acute stress in rats, the neurites change shape and length over several weeks post damage [7, 14]. In preclinical studies in rats, two sensors and/or regulators of stress associated with the prefrontal cortex have been identified. (1) The direct connection with the Executive functions are a set of cognitive skills that allow for anticipation and establishment of goals, the design of plans and programs, the initiation of activities and mental operations, self-regulation, task monitoring, the precise selection of behavioral, flexibility for cognitive tasks, and organization in time and space. On the other hand, various authors have defined cognitive control as an "executive control" which refers to a set of higher order processes that modulate the interactions of the environmental context of the subject [22, 23]. These functions aim to optimize the selection, management, and coordination that underlie aspects such as perception, memory, and execution [24].

According to Diamond [25], the key executive functions are inhibitory control, working memory, and cognitive flexibility. Other functions, such as reasoning, planning, and organization, would be built from the three main functions. Other authors have defined the executive functions using warm and cold. Warm executive functions are cognitive/emotional processes related to decision-making, motivation, and social cognition. Cold executive functions are related to the rational/cognitive process of high order skills that are used when emotions are not an important factor [26].

Executive functions can be assessed using neuropsychological tests and are dependent on the prefrontal cortex. The frontal lobes plan, regulate, and control human behavior. This control allows the individual to evaluate and select the most appropriate response and avoid impulsive responses, restraining compulsive behavior, and appetitive behavior. At neural level, the prefrontal cortex, particularly the dorsolateral portion, is a fundamental region involved in executive functions. Other regions, such as the orbitofrontal cortex portion, are closely related to the limbic system. The thalamus and the basal ganglia are brain regions also involved in executive functions [27].

academic performance. The results showed that performance on tasks of short-term memory and working memory was associated with better initial performance of children in reading and math skills. Likewise, analyses of correlation and regression carried out revealed that the visuospatial memory and working memory operated as predictors of children's mathematical performance in all the periods in which they were evaluated. On the other hand, inhibitory control, flexibility, and planning acted as predictors of general learning capacity, but were not

Stress and Cognition: Psychological Basis and Support Resources

http://dx.doi.org/10.5772/intechopen.72566

17

Reyes and colleagues [32] found that the correlation between the variables identified significant relationships between academic performance and executive functions. At the age of 6, significant correlations are found between selective sustained attention and working memory with all the courses understanding that these courses require the constant ability to select the most important information and focus attention for long periods of time within the classroom, mainly in the areas of Math, English, and Social Sciences; considering that the children of 4–6 years have short periods of sustained attention in the presentation of a task, from 6 years, the attention that children can give to a task or to a game can be extended for

In summary, the different studies mentioned show that a good academic achievement is predictive of the executive capacity that individuals have, this must be considered to promote strategies for improvement in the executive functions of the students through training to have

One of the factors that can affect executive functions is stress. As we mentioned earlier, stress occurs when demand exceeds the regulatory capacity of the organism. It is very difficult to determine the extent of the impact and the duration of daily stress, especially if in acute stress situations where the individual is facing situations with a physical or psychological stimulation in which he/she must decide quickly or make an assessment of a particular situation. Stressors promote physiological, psychological, and behavioral reactions, but individuals react differently to stressors. That makes a laboratory setting very useful for the study of the psychophysiological responses to stressors of different nature, which allow evaluate subjects

There is evidence of the negative effect of high levels of circulating of stress-induced glucocorticoids on cognitive performance [2, 34]. The different studies related to declarative memory tasks have focused on the hippocampus [35, 36]; some other studies have examined the effect of stress on working memory [37], which has shown that the administration of cortisol can also adversely affect the performance of the working memory [35, 38]. Some authors have evaluated one or two components of the executive functions under conditions of stress where they have observed that stress can reduce attention in inhibition [39, 40]; the administration of tasks assessed with paradigms of dual task was improved under stressful conditions [41], while the administration of tasks through a paradigm change of tasks was observed to be impaired under conditions of stress [42]. A systematic study investigated the effect of stress in five components of the executive functions: attention and inhibition, task management,

associated with the performance of any specific domain [31].

a long time.

impact in academic performance.

**3.2. Stress and executive functions**

under controlled modulatory variables [33].

#### **3.1. Executive functions and academic performance**

When a child enters school, he/she is in need of a series of cognitive processes (comparison, attention, differentiation) to be able to develop reading and writing and mathematical calculation, that is why, a proper neurological maturation is essential to deal successfully with the demands of learning, as the alteration of cognitive processes translates into learning problems [28].

The predictive effect of executive functions on academic performance is important for the proper adaptation of the individual to the specific requirements of a learning context; the correct development of the executive processes makes it possible for the individual to recognize and represent mentally different problematic situations, in addition to designing strategies for the resolution of them. There have been some works that have focused on evaluating executive function and academic performance.

A study was conducted in which the relationship between performance in mathematics and the performance in tasks of working memory and processing speed was assessed, finding that children with normal performance in the area of mathematics were faster and had greater accuracy in responding to tasks that required numerical identification, recovery and retention of numerical information, and ability to do mathematical calculations in relation to children with poor performance. In error-detection tasks, both groups of children (low performance and normal performance) could recognize the errors without difficulty. However, children with poor performance failed in the detection of such errors at a rate of 1 of 3 tests [29]; one of the explanations of the authors is that there is an inappropriate intervention of the central executive that regulates cognitive processes such as the transmission of information to longterm memory, planning, and recovery strategies.

Blair and Razza [30] conducted a longitudinal study in which they measured the capabilities of the temperamental factor associated with self-control (Effortful Control), understanding of false belief, inhibitory control, and shift of attention. The objective was to study the relationship between some skills involved in executive functions and academic performance in mathematics and language. The results showed that the scores of children at the initial level, in shift of attention and inhibitory control, did not predict performance in the tasks of phonological and letter recognition. However, the scores on inhibitory control were related with the performance at the mathematical tasks during pre-school period (3–5 years). During this period, the scores of inhibitory control and attention shift were associated with the literary capacity of children (phonetic recognition and knowledge of letters).

A longitudinal study in children from 5 to 7 years evaluated the way in which short-term memory, working memory, inhibitory control, cognitive flexibility, and planning impacted on academic performance. The results showed that performance on tasks of short-term memory and working memory was associated with better initial performance of children in reading and math skills. Likewise, analyses of correlation and regression carried out revealed that the visuospatial memory and working memory operated as predictors of children's mathematical performance in all the periods in which they were evaluated. On the other hand, inhibitory control, flexibility, and planning acted as predictors of general learning capacity, but were not associated with the performance of any specific domain [31].

Reyes and colleagues [32] found that the correlation between the variables identified significant relationships between academic performance and executive functions. At the age of 6, significant correlations are found between selective sustained attention and working memory with all the courses understanding that these courses require the constant ability to select the most important information and focus attention for long periods of time within the classroom, mainly in the areas of Math, English, and Social Sciences; considering that the children of 4–6 years have short periods of sustained attention in the presentation of a task, from 6 years, the attention that children can give to a task or to a game can be extended for a long time.

In summary, the different studies mentioned show that a good academic achievement is predictive of the executive capacity that individuals have, this must be considered to promote strategies for improvement in the executive functions of the students through training to have impact in academic performance.

#### **3.2. Stress and executive functions**

allows the individual to evaluate and select the most appropriate response and avoid impulsive responses, restraining compulsive behavior, and appetitive behavior. At neural level, the prefrontal cortex, particularly the dorsolateral portion, is a fundamental region involved in executive functions. Other regions, such as the orbitofrontal cortex portion, are closely related to the limbic system. The thalamus and the basal ganglia are brain regions also involved in

When a child enters school, he/she is in need of a series of cognitive processes (comparison, attention, differentiation) to be able to develop reading and writing and mathematical calculation, that is why, a proper neurological maturation is essential to deal successfully with the demands

The predictive effect of executive functions on academic performance is important for the proper adaptation of the individual to the specific requirements of a learning context; the correct development of the executive processes makes it possible for the individual to recognize and represent mentally different problematic situations, in addition to designing strategies for the resolution of them. There have been some works that have focused on evaluating

A study was conducted in which the relationship between performance in mathematics and the performance in tasks of working memory and processing speed was assessed, finding that children with normal performance in the area of mathematics were faster and had greater accuracy in responding to tasks that required numerical identification, recovery and retention of numerical information, and ability to do mathematical calculations in relation to children with poor performance. In error-detection tasks, both groups of children (low performance and normal performance) could recognize the errors without difficulty. However, children with poor performance failed in the detection of such errors at a rate of 1 of 3 tests [29]; one of the explanations of the authors is that there is an inappropriate intervention of the central executive that regulates cognitive processes such as the transmission of information to long-

Blair and Razza [30] conducted a longitudinal study in which they measured the capabilities of the temperamental factor associated with self-control (Effortful Control), understanding of false belief, inhibitory control, and shift of attention. The objective was to study the relationship between some skills involved in executive functions and academic performance in mathematics and language. The results showed that the scores of children at the initial level, in shift of attention and inhibitory control, did not predict performance in the tasks of phonological and letter recognition. However, the scores on inhibitory control were related with the performance at the mathematical tasks during pre-school period (3–5 years). During this period, the scores of inhibitory control and attention shift were associated with the literary

A longitudinal study in children from 5 to 7 years evaluated the way in which short-term memory, working memory, inhibitory control, cognitive flexibility, and planning impacted on

of learning, as the alteration of cognitive processes translates into learning problems [28].

executive functions [27].

16 Health and Academic Achievement

**3.1. Executive functions and academic performance**

executive function and academic performance.

term memory, planning, and recovery strategies.

capacity of children (phonetic recognition and knowledge of letters).

One of the factors that can affect executive functions is stress. As we mentioned earlier, stress occurs when demand exceeds the regulatory capacity of the organism. It is very difficult to determine the extent of the impact and the duration of daily stress, especially if in acute stress situations where the individual is facing situations with a physical or psychological stimulation in which he/she must decide quickly or make an assessment of a particular situation. Stressors promote physiological, psychological, and behavioral reactions, but individuals react differently to stressors. That makes a laboratory setting very useful for the study of the psychophysiological responses to stressors of different nature, which allow evaluate subjects under controlled modulatory variables [33].

There is evidence of the negative effect of high levels of circulating of stress-induced glucocorticoids on cognitive performance [2, 34]. The different studies related to declarative memory tasks have focused on the hippocampus [35, 36]; some other studies have examined the effect of stress on working memory [37], which has shown that the administration of cortisol can also adversely affect the performance of the working memory [35, 38]. Some authors have evaluated one or two components of the executive functions under conditions of stress where they have observed that stress can reduce attention in inhibition [39, 40]; the administration of tasks assessed with paradigms of dual task was improved under stressful conditions [41], while the administration of tasks through a paradigm change of tasks was observed to be impaired under conditions of stress [42]. A systematic study investigated the effect of stress in five components of the executive functions: attention and inhibition, task management, planning, monitoring, and coding. The results showed that stressed participants had a better performance compared with non-stressed participants in all the components with the exception of the monitoring [43]. One study evaluated the relationship between specific stressors and deficits in executive functions in undergraduate students. The results determined that general social abuse was the factor most correlated with deficits in executive function. Factors such as challenges of development (struggle and dissatisfaction with cognitive and physical attributes and abilities) and dissatisfaction with school were also predictive of diminished executive functions [44].

with aggressive individuals indicate a malfunction in cognitive functioning and decisionmaking. One study found that children who were not involved in bullying situations such as bullies or victims had better scores on intelligence tests. Both victims and bullies had greater difficulties in the inhibitory control according to the reports given by the parent version of the Behavior Rating Inventory of Executive Function (BRIEF); the result suggests a probable

Stress and Cognition: Psychological Basis and Support Resources

http://dx.doi.org/10.5772/intechopen.72566

19

Medeiros and collaborators evaluated decision-making, inhibitory control, working memory, and cognitive flexibility in children. They found that the bully made less favorable decisions in assessments for decision-making, while the group of victims took more time to complete assessments of cognitive flexibility. This study suggests that bullies have difficulties in warm executive functions, while victims have lower performance in cold executive

The association between the low academic performance and the use of alcohol (risk consumption) has been studied by several authors in the literature [51]. Due to their biological limitations in the ability to engage and integrate executive functioning, teens are very susceptible to the noxious consequences of the use of tobacco, alcohol, and other drugs. Unlike adults, alcohol causes greater impact on the brain of adolescents and young adults in the areas of working memory and learning. The early onset of nicotine use leads to deterioration in memory capacity and increases the frequency of episodes of depression and heart irregularities. Marijuana consumption associated with low academic performance has been described [52]. Other drugs, such as stimulants and opioids, are directed to the dopaminergic receptors in the brain and can cause damage throughout life to the development of impulse control and the ability to experience reward. Substance abuse contributes to the delay in skills of the executive

functions and in immature or under-controlled emotional responses

the structure and function of the central nervous system [53].

**4. Strategies for the good academic performance: Physical activity,** 

Several studies conducted on animal and human models provide sufficient evidence for an important relationship between various factors such as physical activity, sleep, and healthy food, with optimal cognitive functioning. This invariably leads to a better academic performance. These studies have been conducted through different stages of development, from prenatal to old age. Some of the cognitive functions that may be affected by the activities or changes throughout life are short-term and long-term memory, learning, attention, spatial memory, and working memory, among others. Evidence suggests that the connection between these cognitive functions, physical activity, nutrition, sleep time, and social interactions have a direct impact on

deficit in executive functioning related to being involved in situations of bullying [49].

functions [50].

**3.4. Addictions**

**sleep, and diet**

**4.1. Physical activity**

Chronic stress can generate high levels of cortisol in the prefrontal cortex, which can lead to an impairment of cognitive functions. There is evidence that stressors such as bullying and addiction can affect the executive functions; although they are not the only existing stressors, they are to be found with higher prevalence in the school setting.

Questions about how stress can affect or improve behavior are important in different contexts and in this particular case on academic performance. One of the factors that interfere suggests that the controllability is a key factor on the impact of stress on behavior; to learn how to control stress-causing factors protects people from the negative effects of stress in tasks of high cognitive demand. In addition, research suggests that the impact of stress on cognitive functioning depends on an individual's response to stressors: moderate responses to stress can lead to improved performance, while extreme responses (high or low) can lead to a low performance [45–47].

Factors such as bullying and addictions stimulate stress by promoting specific neurophysiological responses, followed by alterations in executive functions. Components such as physical activity, good nutrition, and sleep hygiene can reduce academic stress and its neurophysiological consequences (**Figure 3**).

## **3.3. Bullying**

Bullying is characterized by intentional, repetitive, and persistently aggressive behavior causing harm to a victim [48]. Several studies have investigated the social and emotional aspects related to bullying; however, few studies evaluate how cognitive aspects are involved. Studies

**Figure 3.** Interaction of positive and negative components in academic achievement.

with aggressive individuals indicate a malfunction in cognitive functioning and decisionmaking. One study found that children who were not involved in bullying situations such as bullies or victims had better scores on intelligence tests. Both victims and bullies had greater difficulties in the inhibitory control according to the reports given by the parent version of the Behavior Rating Inventory of Executive Function (BRIEF); the result suggests a probable deficit in executive functioning related to being involved in situations of bullying [49].

Medeiros and collaborators evaluated decision-making, inhibitory control, working memory, and cognitive flexibility in children. They found that the bully made less favorable decisions in assessments for decision-making, while the group of victims took more time to complete assessments of cognitive flexibility. This study suggests that bullies have difficulties in warm executive functions, while victims have lower performance in cold executive functions [50].

#### **3.4. Addictions**

The association between the low academic performance and the use of alcohol (risk consumption) has been studied by several authors in the literature [51]. Due to their biological limitations in the ability to engage and integrate executive functioning, teens are very susceptible to the noxious consequences of the use of tobacco, alcohol, and other drugs. Unlike adults, alcohol causes greater impact on the brain of adolescents and young adults in the areas of working memory and learning. The early onset of nicotine use leads to deterioration in memory capacity and increases the frequency of episodes of depression and heart irregularities. Marijuana consumption associated with low academic performance has been described [52]. Other drugs, such as stimulants and opioids, are directed to the dopaminergic receptors in the brain and can cause damage throughout life to the development of impulse control and the ability to experience reward. Substance abuse contributes to the delay in skills of the executive functions and in immature or under-controlled emotional responses
