Turning down the heat: Neural mechanisms of cognitive control for inhibiting task-irrelevant emotional information during adolescence.

One major question in the cognitive neuroscience of cognitive control is whether prefrontal regions contribute to control by upregulating the processing of task-relevant material or by downregulating the processing of task-irrelevant material. Here we take a unique approach to addressing this question by using multi-voxel pattern analysis, which allowed us to determine the degree to which each of the task-relevant and task-irrelevant dimensions of a stimulus are being processed in posterior cortex on a trial-by-trial basis. In our study, adolescent participants performed an emotion word - emotional face Stroop task requiring them to determine the emotional valence (positive, negative) of a task-relevant word in the context of a task-irrelevant emotional face. Using mediation models, we determined whether activation of a major cognitive control region, the dorsolateral prefrontal cortex (DLPFC), influences reaction time on a trial-by-trial basis directly or if it does so indirectly by modulating processing of the task-relevant and/or task-irrelevant information in posterior brain regions. To examine the specificity of the effects observed for the DLPFC, similar analyses were performed for the amygdala, a brain region involved in processing of the salient task-irrelevant emotional information. For both congruent and incongruent trials, increased DLPFC activity on a given trial was associated with reduced perceptual processing of the task-irrelevant face, consistent with the idea that top-down cognitive control can modulate processing of task-irrelevant information. No effect of DLPFC activity was observed on processing of the task-relevant word. However, increased processing of the task-relevant word was associated with longer RT on congruent trials but not incongruent trials, which may reflect a need for greater processing of the task-relevant word to overcome any influence of the pre-potent task-irrelevant face. In a more exploratory aspect of our investigation, multi-level moderated mediation models were used to examine the influence of individual differences on the observed brain-behavior relationships. For congruent trials, the influence of task-irrelevant face processing on RT was decreased in individuals with higher self-reported Executive Control and increased in those with higher levels of self-reported Negative Affect. These results suggest that cognitive control regions in prefrontal cortex during adolescence can suppress the processing of task-irrelevant information in sensory cortex to influence performance (RT). The processing of task-relevant information may also influence performance, but such processing did not reveal evidence of being modulated by cognitive control regions. Moreover, these effects are sensitive to individual differences in the self-reported ability to exert cognitive and affective control. As such, we provide insights into the more precise mechanisms by which cognitive control influences task performance on a trial-by-trial basis during adolescence.

The influence of stressful life events, psychopathy, and their interaction on internalizing and externalizing psychopathology.

Exposure to stressful life events increases risk for both internalizing and externalizing psychopathology, but less is known about moderators of the association between stressful life events and psychopathology. The present study examined the influence of stressful life events, psychopathy, and their interaction on internalizing and externalizing psychopathology in 3877 individuals from the community. We hypothesized that (1) exposure to stressful life events would be a transdiagnostic risk factor for psychopathology, (2) primary and secondary psychopathy would be differentially associated with internalizing psychopathology, and (3) primary psychopathy would moderate the association between stressful life events and internalizing psychopathology. Confirming existing findings, our results were consistent with the first and second hypotheses. In contrast to our third hypothesis, primary psychopathy was not associated with stressful life events in childhood, inconsistently associated with stressful life events in adolescence, and did not moderate the association between stressful life events and internalizing psychopathology. Furthermore, stressful life events across development were associated with secondary psychopathy and internalizing and externalizing psychopathology. We also found similar associations between stressful life events, psychopathy, and psychopathology in females and males. Future studies investigating the impact of stressful life events on psychopathology should include psychopathic traits and stress-reactivity.

Overlapping and distinct neural correlates of imitating and opposing facial movements.

Previous studies have demonstrated that imitating a face can be relatively automatic and reflexive. In contrast, opposing facial expressions may require engaging flexible, cognitive control. However, few studies have examined the degree to which imitation and opposition of facial movements recruit overlapping and distinct neural regions. Furthermore, little work has examined whether opposition and imitation of facial movements differ between emotional and averted eye gaze facial expressions. This study utilized a novel task with 40 participants to compare passive viewing, imitation and opposition of emotional faces looking forward and neutral faces with averted eye gaze [(3: Look, Imitate, Oppose) x (2: Emotion, Averted Eye)]. Imitation and opposition of both types of facial movements elicited overlapping activation in frontal, premotor, superior temporal and anterior intraparietal regions. These regions are recruited during cognitive control, face processing and mirroring tasks. For both emotional and averted eye gaze photos, opposition engaged the superior frontal gyrus, superior temporal sulcus and the anterior intraparietal sulcus to a greater extent compared to imitation. Finally, stimulus type and instruction interacted, such that for the eye gaze condition only, greater activation was observed in the dorsal anterior cingulate (dACC) during opposition compared to imitation, while no significant dACC differences were observed for the emotional expression conditions, which instead showed significantly greater activation in the middle and frontal pole. Overall these results showed significant overlap between imitation and opposition, as well as increased activation of these regions to generate an opposing facial movement relative to imitating.

Genetic and environmental influences on emotion regulation: A twin study of cognitive reappraisal and expressive suppression.

Previous studies have established that personality traits related to emotionality are moderately heritable. However, the relative heritability of the strategies people use to regulate emotions is unknown. The present study compared the magnitude of additive genetic, shared environmental, and nonshared environmental influences on 2 commonly used emotion regulation strategies: cognitive reappraisal and expressive suppression. In 743 twin pairs (1,486 twins), we replicated previous estimates of heritability of neuroticism (a2 = .41). Furthermore, cognitive reappraisal was significantly less heritable and more influenced by nonshared environment (a2 = .20; e2 = .80) than either neuroticism or suppression (a2 = .35; e2 = .65), another emotion regulation strategy. Finally, Cholesky decomposition modeling suggested that while there were common genetic and environmental influences on neuroticism, reappraisal and suppression, there were also significant nonshared environmental influences common between reappraisal and adaptive emotional functioning after controlling for neuroticism and suppression. These findings highlight that different aspects of emotional processing, even the use of different emotion regulation strategies, are differentially heritable. The importance of the nonshared environmental influences specific to reappraisal and adaptive emotional functioning speaks to the potential impact of social context, social partners, and psychosocial interventions on reappraisal habits. (PsycINFO Database Record

Differences in frontal and limbic brain activation in a small sample of monozygotic twin pairs discordant for severe stressful life events.

Monozygotic twin pairs provide a valuable opportunity to control for genetic and shared environmental influences while studying the effects of nonshared environmental influences. The question we address with this design is whether monozygotic twins selected for discordance in exposure to severe stressful life events during development (before age 18) demonstrate differences in brain activation during performance of an emotional word-face Stroop task. In this study, functional magnetic resonance imaging was used to assess brain activation in eighteen young adult twins who were discordant in exposure to severe stress such that one twin had two or more severe events compared to their control co-twin who had no severe events. Twins who experienced higher levels of stress during development, compared to their control co-twins with lower stress, exhibited significant clusters of greater activation in the ventrolateral and medial prefrontal cortex, basal ganglia, and limbic regions. The control co-twins showed only the more typical recruitment of frontoparietal regions thought to be important for executive control of attention and maintenance of task goals. Behavioral performance was not significantly different between twins within pairs, suggesting the twins with stress recruited additional neural resources associated with affective processing and updating working memory when performing at the same level. This study provides a powerful glimpse at the potential effects of stress during development while accounting for shared genetic and environmental influences.

Familial risk and ADHD-specific neural activity revealed by case-control, discordant twin pair design.

Individuals with ADHD, as well as their family members who do not meet clinical criteria, have shown deficits in executive function. However, it remains unclear whether underlying neural alterations are familial or ADHD-specific. To investigate this issue, neural activation underlying executive function was assessed using functional magnetic resonance imaging during performance of a Stroop task in three groups of individuals: 20 young adults who were diagnosed with ADHD in childhood, their 20 dizygotic co-twins without ADHD in childhood, and 20 unrelated controls selected from dizygotic twin pairs in which neither twin had ADHD in childhood (total n=60). Implicating the frontoparietal network as a location of effects specific to ADHD, activation in the superior frontal (Brodmann's Area - BA 6) and parietal regions (BA 40) was significantly reduced in twins with childhood ADHD compared to both their control co-twins and unrelated control twins. Consistent with familial influences, activity in the anterior cingulate and insula was significantly reduced in both the twins with ADHD and their co-twins compared to the unrelated controls. These results show that both ADHD-specific and familial influences related to an ADHD diagnosis impact neural systems underlying executive function.

A penny for your thoughts: dimensions of self-generated thought content and relationships with individual differences in emotional wellbeing.

A core aspect of human cognition involves overcoming the constraints of the present environment by mentally simulating another time, place, or perspective. Although these self-generated processes confer many benefits, they can come at an important cost, and this cost is greater for some individuals than for others. Here we explore the possibility that the costs and benefits of self-generated thought depend, in part, upon its phenomenological content. To test these hypotheses, we first developed a novel thought sampling paradigm in which a large sample of young adults recalled several recurring thoughts and rated each thought on multiple content variables (i.e., valence, specificity, self-relevance, etc.). Next, we examined multi-level relationships among these content variables and used a hierarchical clustering approach to partition self-generated thought into distinct dimensions. Finally, we investigated whether these content dimensions predicted individual differences in the costs and benefits of the experience, assessed with questionnaires measuring emotional health and wellbeing. Individuals who characterized their thoughts as more negative and more personally significant scored higher on constructs associated with Depression and Trait Negative Affect, whereas those who characterized their thoughts as less specific scored higher on constructs linked to Rumination. In contrast, individuals who characterized their thoughts as more positive, less personally significant, and more specific scored higher on constructs linked to improved wellbeing (Mindfulness). Collectively, these findings suggest that the content of people's inner thoughts can (1) be productively examined, (2) be distilled into several major dimensions, and (3) account for a large portion of variability in their functional outcomes.

Phenotypic and genetic analyses of the Wisconsin Card Sort.

The present study assessed the factor structure and etiology of traditional perseverative and nonperseverative errors, and six narrowly defined errors that occur during the Wisconsin Card Sorting Task (WCST). A computer-administered version of the WCST, designed to maximize the variance in a nonclinical sample, was used. Phenotypic factor analysis and twin models were used to examine the structure and genetic and environmental etiology in 191 monozygotic and 165 dizygotic adolescent twin pairs. Factor analysis did not support the traditional division of errors into perseverative and nonperseverative errors. Heritability of individual indices was small to moderate (a(2) = 0.10 - 0.42), with varying significance. Estimates of shared environment (c(2) = 0.00 - 0.14) were not significant. The best fitting multivariate genetic model had one genetic factor, with specific variance and covariance due to nonshared environmental influences. These results suggest that there are common underlying genetic influences on WCST indices, along with index-specific environmental variance that does not correspond to the traditional division between perseverative and nonperseverative errors.

Effects of self-evaluation on the P300 event-related potential.

The effects of self evaluation on the P300 event-related potential (ERP) were explored with 56 participants (16 men, 40 women; M age = 23.4 yr., SD = 1.2) across three conditions. The conditions included (1) a standard ERP auditory oddball discrimination between a random target (15% occurrence) and standard stimuli (85% occurrence), (2) the oddball task followed by the additional cognitive task of maintaining a mental count of the target tones, and (3) the oddball task followed by the additional cognitive task of self-evaluating whether they felt surprised by the current occurrence of the target tone. The added cognitive requirements for Conditions 2 and 3 required the subjects to maintain a cognitive readiness for the secondary stimulus-related task during their sensory discrimination response for the standard oddball task. During the self-evaluation condition, the P300 amplitude was significantly larger across all recording locations than the regular oddball condition and the cognitive count condition.