Individual differences in executive functioning: implications for stress regulation

The Phenotype of Loneliness

Goossens' (in press) review nicely maps the progression of scientific research from its early focus on loneliness as a dysphoric state that results from the discrepancy between a person's ideal and actual social relationships to its current emphasis on the centrality of loneliness to our very nature as a social species, and he argues that developmental science throughout Europe has a great deal to contribute to our understanding of this construct. He concludes that psychologists should care about research on loneliness for five reasons: (i) it is a well-defined phenotype, (ii) it shows both high stability and individual differences in rates of change across years, (iii) it has adaptive value and evolutionary significance, (iv) it has a genetic substrate that is moderated by social environments, and (v) it has self-maintaining features that can lead to adverse mental health outcomes. Goossen's (2012) review is rife with information and ideas. We focus here on two additional important reasons and on the phenotype of loneliness.

Function and dysfunction of prefrontal brain circuitry in alcoholic Korsakoff's syndrome

The signature symptom of alcohol-induced persisting amnestic disorder, more commonly referred to as alcoholic Korsakoff's syndrome (KS), is anterograde amnesia, or memory loss for recent events, and until the mid 20th Century, the putative brain damage was considered to be in diencephalic and medial temporal lobe structures. Overall intelligence, as measured by standardized IQ tests, usually remains intact. Preservation of IQ occurs because memories formed before the onset of prolonged heavy drinking--the types of information and abilities tapped by intelligence tests--remain relatively well preserved compared with memories recently acquired. However, clinical and experimental evidence has shown that neurobehavioral dysfunction in alcoholic patients with KS does include nonmnemonic abilities, and further brain damage involves extensive frontal and limbic circuitries. Among the abnormalities are confabulation, disruption of elements of executive functioning and cognitive control, and emotional impairments. Here, we discuss the relationship between neurobehavioral impairments in KS and alcoholism-related brain damage. More specifically, we examine the role of damage to prefrontal brain systems in the neuropsychological profile of alcoholic KS.

Muscle sympathetic response to arousal predicts neurovascular reactivity during mental stress

Mental stress often begins with a sudden sensory (or internal) stimulus causing a brief arousal reaction, and is followed by a more long lasting stress phase. Both arousal and stress regularly induce blood pressure (BP) increases whereas effects on muscle sympathetic nerve activity (MSNA) are variable. Here we have compared responses of MSNA and BP during arousal induced by an electrical skin stimulus and mental stress evoked by a 3 min paced auditory serial arithmetic test (PASAT) in 30 healthy males aged 33 ± 10 years. In addition, recordings were made of ECG, respiratory movements, electrodermal activity and perceived stress. We also monitored corresponding effects of a cold test (CT: 2 min immersion of a hand in ice water). The arousal stimulus evoked significant inhibition of one or two MSNA bursts in 16 subjects, who were classified as responders; the remaining 14 subjects were non-responders. During mental stress responders showed a significant decrease of MSNA and a lesser BP increase compared to non-responders. In non-responders MSNA was unchanged or increased. Perceived stress was higher in non-responders (P = 0.056), but other measures were similar in the two groups. In non-responders mental stress and the cold test induced increases of BP that lasted throughout the subsequent rest period. During the cold test MSNA and BP increased equally in responders and non-responders. In the whole group of subjects, there was a significant correlation (r = 0.80, P < 0.001) between MSNA responses induced by arousal and by mental stress but not between responses evoked by arousal and the cold test (r < 0.1, P > 0.6). Additionally arousal-induced MSNA change was positively correlated with blood pressure changes during MS (systolic BP: r = 0.48; P < 0.01; diastolic BP: r = 0.42; P < 0.05) but not with blood pressure changes during CT. We conclude that in males the MSNA response to arousal predicts the MSNA and BP responses to mental stress.

Development and validation of a personality assessment instrument for traditional korean medicine: sasang personality questionnaire

Objective. Sasang typology is a traditional Korean medicine based on the biopsychosocial perspectives of Neo-Confucianism and utilizes medical herbs and acupuncture for type-specific treatment. This study was designed to develop and validate the Sasang Personality Questionnaire (SPQ) for future use in the assessment of personality based on Sasang typology. Design and Methods. We selected questionnaire items using internal consistency analysis and examined construct validity with explorative factor analysis using 245 healthy participants. Test-retest reliability as well as convergent validity were examined. Results. The 14-item SPQ showed acceptable internal consistency (Cronbach's alpha = .817) and test-retest reliability (r = .837). Three extracted subscales, SPQ-behavior, SPQ-emotionality, and SPQ-cognition, were found, explaining 55.77% of the total variance. The SPQ significantly correlated with Temperament and Character Inventory novelty seeking (r = .462), harm avoidance (r = -.390), and NEO Personality Inventory extraversion (r = .629). The SPQ score of the So-Eum (24.43 ± 4.93), Tae-Eum (27.33 ± 5.88), and So-Yang (30.90 ± 5.23) types were significantly different from each other (P < .01). Conclusion. Current results demonstrated the reliability and validity of the SPQ and its subscales that can be utilized as an objective instrument for conducting personalized medicine research incorporating the biopsychosocial perspective.

Temperament and Attentional Bias in Vocal Emotional Stroop Tasks

Human information processing is influenced by the affective quality of pleasant and unpleasant stimuli. A widely known example is the emotional variant of the colour–naming Stroop task. Although participants are not instructed to attend to valence, it nevertheless influences response times. We studied how persons differ in ignoring the irrelevant valence of stimuli and how such differences are related to personality traits. In two emotional Stroop tasks using a vocal response mode, participants were instructed to name the colour of unpleasant and pleasant words presented in different physical colours. In Study 2, we introduced a second task to increase the cognitive load. Across both studies, extraversion and approach temperament were associated with higher interferences by pleasant words. Neuroticism and avoidance temperament, however, were associated with higher interferences by unpleasant words only when cognitive load increased because of a task switch. This finding suggests that highly neurotic individuals can mitigate influences of emotional stimuli on information processing under conditions of low cognitive load. Copyright © 2012 John Wiley & Sons, Ltd.

Neuropsychopharmacology and neurogenetic aspects of executive functioning: should reward gene polymorphisms constitute a diagnostic tool to identify individuals at risk for impaired judgment?

Executive functions are processes that act in harmony to control behaviors necessary for maintaining focus and achieving outcomes. Executive dysfunction in neuropsychiatric disorders is attributed to structural or functional pathology of brain networks involving prefrontal cortex (PFC) and its connections with other brain regions. The PFC receives innervations from different neurons associated with a number of neurotransmitters, especially dopamine (DA). Here we review findings on the contribution of PFC DA to higher-order cognitive and emotional behaviors. We suggest that examination of multifactorial interactions of an individual's genetic history, along with environmental risk factors, can assist in the characterization of executive functioning for that individual. Based upon the results of genetic studies, we also propose genetic mapping as a probable diagnostic tool serving as a therapeutic adjunct for augmenting executive functioning capabilities. We conclude that preservation of the neurological underpinnings of executive functions requires the integrity of complex neural systems including the influence of specific genes and associated polymorphisms to provide adequate neurotransmission.

The role of prospective memory in medication adherence: a review of an emerging literature

Although neurocognitive impairment is an established risk factor for medication nonadherence, standard neurocognitive tests developed for clinical purposes may not fully capture the complexities of non-adherence behavior or effectively inform theory-driven interventions. Prospective memory, an innovative cognitive construct describing one's ability to remember to do something at a later time, is an understudied factor in the detection and remediation of medication non-adherence. This review orients researchers to the construct of prospective memory, summarizes empirical evidence for prospective memory as a risk factor for non-adherence, discusses the relative merits of current measurement techniques, and highlights potential prospective memory-focused intervention strategies. A comprehensive literature review was conducted of published empirical studies investigating prospective memory and medication adherence. Overall, reviewed studies suggest that prospective memory is an important component of medication adherence, providing incremental ecological validity over established predictors. Findings indicate that prospective memory-based interventions might be an effective means of improving adherence.

The influence of functional social support on executive functioning in middle-aged African Americans

Social support has a positive influence on cognitive functioning and buffers cognitive decline in older adults. This study examined the relations between social support and executive functioning in middle-aged adults. A community-based sample of African Americans completed the Interpersonal Support Evaluation List, a measure of functions of social support, and two measures of executive functioning, the Stroop Color and Word Test and the Wisconsin Card Sorting Test (WCST). Hierarchical regression analyses were used to explore the hypothesis that different facets of perceived social support influence performance on measures of executive functioning. After controlling for age, gender, and education, social support facets including belonging support, self-esteem support, appraisal support, and tangible support were significant predictors of Stroop performance. In addition, tangible support significantly predicted WCST performance. These findings add to previous literature on social support and cognition; however, findings for middle-aged adults are unique and suggest that social support has a positive influence on some executive functions in African Americans prior to old age.

Pathological personality traits among patients with absent, current, and remitted substance use disorders

Personality traits may provide underlying risk factors for and/or sequelae to substance use disorders (SUDs). In this study Schedule for Nonadaptive and Adaptive Personality (SNAP) traits were compared in a clinical sample (N=704, age 18-45) with current, past, or no historical alcohol or non-alcohol substance use disorders (AUD and NASUD) as assessed by DSM-IV semi-structured interview. Results corroborated previous research in showing associations of negative temperament and disinhibition to SUD, highlighting the importance of these traits for indicating substance use proclivity or the chronic effects of substance use. Certain traits (manipulativeness, self-harm, disinhibition, and impulsivity for AUD, and disinhibition and exhibitionism for NASUD) were higher among individuals with current relative to past diagnoses, perhaps indicating concurrent effects of substance abuse on personality. The positive temperament characteristics detachment and entitlement distinguished AUDs and NASUDs, respectively, perhaps clarifying why this higher order trait tends to show limited relations to SUD generally. These findings suggest the importance of systematically integrating pathological and normative traits in reference to substance-related diagnosis.

Effects of stress on alcohol drinking: a review of animal studies

RATIONALE

While stress is often proposed to play a significant role in influencing alcohol consumption, the relationship between stress and alcohol is complex and poorly understood. Over several decades, stress effects on alcohol drinking have been studied using a variety of animal models and experimental procedures, yet this large body of literature has generally produced equivocal results.

OBJECTIVES

This paper reviews results from animal studies in which alcohol consumption is evaluated under conditions of acute/sub-chronic stress exposure or models of chronic stress exposure. Evidence also is presented indicating that chronic intermittent alcohol exposure serves as a stressor that consequently influences drinking.

RESULTS

The effects of various acute/sub-chronic stress procedures on alcohol consumption have generally been mixed, but most study outcomes suggest either no effect or decreased alcohol consumption. In contrast, most studies indicate that chronic stress, especially when administered early in development, results in elevated drinking later in adulthood. Chronic alcohol exposure constitutes a potent stressor itself, and models of chronic intermittent alcohol exposure reliably produce escalation of voluntary alcohol consumption.

CONCLUSIONS

A complex and dynamic interplay among a wide array of genetic, biological, and environmental factors govern stress responses, regulation of alcohol drinking, and the circumstances in which stress modulates alcohol consumption. Suggestions for future directions and new approaches are presented that may aid in developing more sensitive and valid animal models that not only better mimic the clinical situation, but also provide greater understanding of mechanisms that underlie the complexity of stress effects on alcohol drinking.

Associations between cognitive function and naturally occurring daily cortisol during middle adulthood: timing is everything

OBJECTIVES

We examined associations between cognitive function (CF) and the naturally occurring daily cortisol levels using data from the Midlife in the United States survey and the National Study of Daily Experiences.

METHODS

A national sample of 1,500 (mean age = 57 years; range = 33-84, 56% female) completed a phone-based battery of cognitive tasks and 3-6 months later provided saliva samples upon waking, 30 min after waking, at lunch time, and at bedtime on 4 consecutive days.

RESULTS

Higher CF, particularly executive function, was associated with healthier daily cortisol profiles, including a steeper diurnal cortisol slope, higher morning cortisol levels, and lower afternoon and evening cortisol levels.

DISCUSSION

The results indicate that better CF is associated with healthier profiles of naturally occurring cortisol and underscore the importance of the timing of cortisol sampling.

Executive function profiles of pedophilic and nonpedophilic child molesters

There is increasing evidence of neurocognitive dysfunction among child molesters, supporting the notion of brain anomalies among pedophiles. However, approximately half of child molesters are not pedophilic (i.e., are not primarily attracted to children), and neurocognitive differences between pedophilic (PED) and nonpedophilic (NPED) child molesters are not well understood. The purpose of this study was to assess neurocognition, specifically executive functioning (EF), among phallometrically defined PED and NPED child molesters, relative to nonsexual offenders (NSO). Participants (N = 89) were compared on seven EF domains. Results revealed that (a) child molesters exhibited an overall executive profile that was different from that of NSOs, with PEDs differing from NSOs but not from NPEDs; (b) child molesters on the whole performed better than NSOs on abstract reasoning and more poorly on inhibition; and (c) PEDs performed better than NPEDs on planning and exhibited better overall performance accuracy relative to NPEDs. These results suggest that PEDs exhibit a more deliberate, planful response style characterized by greater self-monitoring; whereas NPEDs appear to respond more impulsively. The current report further elucidates neurocognition among child molesters and highlights the need for future research examining subtypes of child molesters.

The Adaptive Calibration Model of stress responsivity

This paper presents the Adaptive Calibration Model (ACM), an evolutionary-developmental theory of individual differences in the functioning of the stress response system. The stress response system has three main biological functions: (1) to coordinate the organism's allostatic response to physical and psychosocial challenges; (2) to encode and filter information about the organism's social and physical environment, mediating the organism's openness to environmental inputs; and (3) to regulate the organism's physiology and behavior in a broad range of fitness-relevant areas including defensive behaviors, competitive risk-taking, learning, attachment, affiliation and reproductive functioning. The information encoded by the system during development feeds back on the long-term calibration of the system itself, resulting in adaptive patterns of responsivity and individual differences in behavior. Drawing on evolutionary life history theory, we build a model of the development of stress responsivity across life stages, describe four prototypical responsivity patterns, and discuss the emergence and meaning of sex differences. The ACM extends the theory of biological sensitivity to context (BSC) and provides an integrative framework for future research in the field.

Academic procrastination in college students: the role of self-reported executive function

Procrastination, or the intentional delay of due tasks, is a widespread phenomenon in college settings. Because procrastination can negatively impact learning, achievement, academic self-efficacy, and quality of life, research has sought to understand the factors that produce and maintain this troublesome behavior. Procrastination is increasingly viewed as involving failures in self-regulation and volition, processes commonly regarded as executive functions. The present study was the first to investigate subcomponents of self-reported executive functioning associated with academic procrastination in a demographically diverse sample of college students aged 30 years and below (n = 212). We included each of nine aspects of executive functioning in multiple regression models that also included various demographic and medical/psychiatric characteristics, estimated IQ, depression, anxiety, neuroticism, and conscientiousness. The executive function domains of initiation, plan/organize, inhibit, self-monitor, working memory, task monitor, and organization of materials were significant predictors of academic procrastination in addition to increased age and lower conscientiousness. Results enhance understanding of the neuropsychological correlates of procrastination and may lead to practical suggestions or interventions to reduce its harmful effects on students' academic performance and well-being.

Executive function and survival in the context of chronic illness

BACKGROUND

Individual differences in executive function (EF) have been shown to predict risk factors for chronic illness. It is not currently known whether EFs also predict survival time following a diagnosis of a chronic illness.

PURPOSE

The objective of this investigation was to examine the association between individual differences in EF and survival time among individuals suffering from one or more chronic illness.

METHODS

A sample of 162 community-dwelling older adults who suffered from a chronic illness at baseline underwent thorough medical and neurological examinations to ensure freedom from actual or probable dementia. Participants completed cognitive testing and were subsequently followed for 10 years; survival was assessed as survival time over the follow-up interval.

RESULTS

Findings indicated that individual differences in EF predicted survival time, and this association held when adjustments were made for demographic variables (age, sex), education, and body mass index.

CONCLUSION

Individual differences in EF may be important determinants of survival in the context of chronic illness.

Job strain related to cognitive failure in naval personnel

The Naval Service Stress Study (2007-2012) is investigating job strain, its characteristics, causes and distribution in the Service. Data from phases I, II and III of the study (January 2007, June 2007 and January 2008) were analysed to determine the relationship between General Health questionnaire scores and a score on the Cognitive Failures Questionnaire (CFQ) completed at phase III. Of 791 personnel who completed questionnaires at all phases, 43.6% had no job strain at any phase, whereas 9.9% had strain on all three occasions ('chronic strain'). 27% had strain at one of the three phases and 19% had strain at two of the three phases. The particular phase at which job strain was experienced was not related to CFQ score at phase III, whereas the total strain experienced over the period was related. High strain over the year was the strongest predictor of high CFQ score. A 'strain dose' variable, which combined both the amount of strain exposure and the timing of the exposure, explained little additional variance in CFQ score. The findings might be interpreted to indicate that a high CFQ score is a vulnerability factor for adverse reactions to work stress. The hypothesis that recent job strain elevates CFQ score was not supported. STATEMENT OF RELEVANCE: Current models of occupational stress focus on psychosocial factors and much of the advice about stress management in organisations is centred on the identification and control of psychosocial risk factors. The present paper provides evidence that cognitive factors are also important and suggests that support for those with poor executive function should be part of stress management in complex environments.

The role of DHEA in relation to problem solving and academic performance

Dehydroepiandrosterone (DHEA) has been correlated with lower susceptibility to anxiety and mood disturbance. Since coping styles have been shown to be a critical component of academic achievement, we aimed to assess the relationship between DHEA and coping mechanisms in college students. Participants were recruited and tested twice, one week apart. Cardiovascular measurements and saliva samples were taken for each participant. The behavioral task consisted of a set of anagrams of increasing difficulty (possible to impossible). American College Testing (ACT) scores, number of college courses failed and dropped along with current grade point average (GPA) were recorded. Results indicated that successfully coping with challenging tasks is a function of behavioral flexibility and physiological neuroprotection. When presented with challenging tasks, individuals who vary their behavioral response to fit the task's demands have the lowest probability of failing the task. The same individuals also have higher levels of resiliency hormones, demonstrated by a lower ratio of cortisol versus DHEA levels.

Understanding design fluency: motor and executive contributions

Design Fluency (DF) is typically assumed to assess planning, cognitive flexibility, and fluency in generation of visual patterns, above and beyond contributions from motor speed (Delis, Kaplan, & Kramer, 2001; Ruff, 1998). The present study examined these assumptions, as little construct validation research has been done in the past. Sixty one community-dwelling elderly participants were administered the DF, Trail Making, and Letter Fluency tests from the Delis-Kaplan Executive Function System (D-KEFS), as well as electronically administered measures of motor planning and motor sequence fluency. Hierarchical regressions were used to parse out unique variance contributions to DF performance. The results showed that generation of novel designs (i.e., the first two trials on the D-KEFS DF) relied primarily on motor planning, the ability to generate novel motor actions, and, to a lesser extent, speed of drawing with a writing implement. In contrast, generation of unique designs while switching (i.e., the third trial on the D-KEFS DF) relied primarily on visual scanning and perhaps visual-attentional resources. These findings highlight the wisdom of interpreting the switching trial of the D-KEFS DF separately. Interestingly, cognitive flexibility did not contribute to performance on any of the three D-KEFS DF trials.

Inter-individual differences in neurobiology as vulnerability factors for affective disorders: implications for psychopharmacology

Susceptibility to affective disorders is individually different, and determined both by genetic variance and life events that cause significant differences in the CNS structure and function between individual subjects. Therefore it is plausible that search for the inter-individual differences in endophenotypes that mediate the effects of causal factors, both genetic and environmental, will reveal the substrates for vulnerability, help to clarify pathogenetic mechanisms, and possibly aid in developing strategies to discover better, more personalized treatments. This review first examines comparatively a number of animal models of human affect and affect-related disorders that rely on persistent inter-individual differences, and then highlights some of the neurobiological findings in these models that are compatible with much of research in human behavioural and personality traits. Many behaviours occur in specific combinations in several models, but often remarkable dissociations are observed, providing a variety of constellations of traits. It is concluded that more systematic comparative experimentation on behaviour and neurobiology in different models is warranted to reveal possible "building blocks" of affect-related personality common in animals and humans. Looking into the perspectives in psychopharmacology the focus is placed on probable associations of inter-individual differences with brain structure and function, personality and coping strategies, and psychiatric vulnerability, highlighting some unexpected interactions between vulnerability endophenotypes, adverse life events, and behavioural traits. It is argued that further studies on inter-individual differences in affect and underlying neurobiology should include formal modeling of their epistatic, hierarchical and dynamic nature.

Conscientiousness, career success, and longevity: a lifespan analysis

BACKGROUND

Markers of executive functioning, such as prudent planning for the future and impulse control, are related to conscientiousness and may be central to both occupational success and health outcomes.

PURPOSE

The aim of the study was to examine relations among conscientiousness, career success, and mortality risk across a 65-year period.

METHODS

Using data derived from 693 male participants in the Terman Life Cycle Study, we examined associations among childhood personality, midlife objective career success, and lifelong mortality risk through 2006.

RESULTS

Conscientiousness and career success each predicted lower mortality risk (N = 693, relative hazard (rh) = 0.82 [95% confidence interval = 0.74, 0.91] and rh = 0.80 [0.71, 0.91], respectively), with both shared and unique variance. Importantly, childhood personality moderated the success-longevity link; conscientiousness was most relevant for least successful individuals.

CONCLUSION

Conscientiousness and career success predicted longevity, but not in a straightforward manner. Findings highlight the importance of lifespan processes.