Extraversion, neuroticism, and the electrocortical response to monetary rewards in adolescent girls

Neural response to rewards moderates the within-person association between daily positive events and positive affect during a period of stress exposure

Stress and neural responses to reward can interact to predict psychopathology, but the mechanisms of this interaction are unclear. One possibility is that the strength of neural responses to reward can affect the ability to maintain positive affect during stress. In this study, 105 participants completed a monetary reward task to elicit the reward positivity (RewP), an event-related potential sensitive to rewards. Subsequently, during a stressful period, participants reported on their affect nine times a day and on daily positive and negative events for 10 days. Even during heightened stress, experiencing more positive events was associated with increased positive affect. The RewP significantly moderated this association: Individuals with a larger RewP reported greater increases in positive affect when they experienced more positive events, relative to individuals with a smaller RewP. A blunted RewP might contribute to stress susceptibility by affecting how much individuals engage in positive emotion regulation during stress.

Association Between the Visual N1-P2 Complex and Neuroticism

Neuroticism is a personality trait associated with impaired attention, memory, and error detection. Thus, the present study investigated the visual N100 and P200 event-related potentials components associated with attention using a 2-back working memory task in healthy neurotic and nonneurotic participants, evaluated using the Neuroticism, Extraversion, Openness Five Factor Inventory. A total of 35 healthy participants were asked to perform the 2-back task while recording electroencephalographic activity from 64 electrodes on the scalp. Analysis of the N100 and P200 amplitude and latency in high neuroticism and low neuroticism subjects showed an increased P200 amplitude and latency for high neuroticism subjects in the frontal and parietal regions, respectively. However, there were no significant performance differences between the high and low neuroticism subjects for the 2-back working memory task. Therefore, the results suggest that neuroticism is associated with the P200 component elicited in the context of a working memory task.

Resting-State Functional Connectivity Associated With Extraversion and Agreeableness in Adolescence

Although adolescence is a period in which developmental changes occur in brain connectivity, personality formation, and peer interaction, few studies have examined the neural correlates of personality dimensions related to social behavior within adolescent samples. The current study aims to investigate whether adolescents’ brain functional connectivity is associated with extraversion and agreeableness, personality dimensions linked to peer acceptance, social network size, and friendship quality. Considering sex-variant neural maturation in adolescence, we also examined sex-specific associations between personality and functional connectivity. Using resting-state functional magnetic resonance imaging (fMRI) data from a community sample of 70 adolescents aged 12–15, we examined associations between self-reported extraversion and agreeableness and seed-to-whole brain connectivity with the amygdala as a seed region of interest. Then, using 415 brain regions that correspond to 8 major brain networks and subcortex, we explored neural connectivity within brain networks and across the whole-brain. We conducted group-level multiple regression analyses with the regressors of extraversion, agreeableness, and their interactions with sex. Results demonstrated that amygdala connectivity with the postcentral gyrus, middle temporal gyrus, and the temporal pole is positively associated with extraversion in girls and negatively associated with extraversion in boys. Agreeableness was positively associated with amygdala connectivity with the middle occipital cortex and superior parietal cortex, in the same direction for boys and girls. Results of the whole-brain connectivity analysis revealed that the connectivity of the postcentral gyrus, located in the dorsal attention network, with regions in default mode network (DMN), salience/ventral attention network, and control network (CON) was associated with extraversion, with most connections showing positive associations in girls and negative associations in boys. For agreeableness, results of the within-network connectivity analysis showed that connections within the limbic network were positively associated with agreeableness in boys while negatively associated with or not associated with agreeableness in girls. Results suggest that intrinsic functional connectivity may contribute to adolescents’ individual differences in extraversion and agreeableness and highlights sex-specific neural connectivity patterns associated with the two personality dimensions. This study deepens our understanding of the neurobiological correlates of adolescent personality that may lead to different developmental trajectories of social experience.

Acute stress reduces reward-related neural activity: Evidence from the reward positivity

Stress and blunted reward processing are risk factors for Major Depressive Disorder (MDD). The experience of acute stress reduces fMRI correlates of reward-related neural activity; however, few studies have examined how acute stress impacts measures of reward derived from event-related potentials (ERPs). The current study examined the impact of an acute stressor on the Reward Positivity (RewP), an ERP that indexes reward sensitivity, in twenty-six college students. Participants completed a monetary reward task while they placed their left hand in cold water set at 13 °C (i.e. acute stress condition) and again while their hand was placed in room temperature water (i.e. control condition). These conditions were separated by one week and performed in a counter-balanced order across participants. The results revealed that the RewP amplitude was blunted in the acute stress condition compared to the control condition. Moreover, there was a trend toward this effect interacting with self-reported depressive symptoms: the RewP was reduced only among individuals who reported low depressive symptoms. The current study suggests that an acute stressor reduces the RewP, and that this effect might be moderated by current depressive symptoms. Future studies might examine the temporal association between reward processing and stress, and how they interact to predict depressive symptoms.LAY SUMMARYThe current study examined the impact of acute stress on the brain's reward system. The results indicated that acute stress reduced activity within the brain's reward system, particularly among individuals with low depressive symptoms.

Polygenic risk for neuroticism moderates response to gains and losses in amygdala and caudate: Evidence from a clinical cohort

BACKGROUND

Neuroticism is a heritable trait that contributes to the vulnerability to depression. We used polygenic risk scores (PRS) to examine genetic vulnerability to neuroticism and its associations with reward/punishment processing in a clinical sample with mood, anxiety, and substance use disorders. It was hypothesized that higher PRS for neuroticism is associated with attenuated neural responses to reward/punishment.

METHOD

Four hundred sixty-nine participants were genotyped and their PRSs for neuroticism were computed. Associations between PRS for neuroticism and anticipatory processing of monetary incentives were examined using functional magnetic resonance imaging.

RESULTS

Individuals with higher PRS for neuroticism showed less anticipatory activation in the left amygdala and caudate region to incentives regardless of incentive valence. Further, these individuals exhibited altered sensitivity to gain/loss processing in the right anterior insula. Higher PRSs for neuroticism were also associated with reduced processing of gains in the precuneus.

LIMITATIONS

The study population consisted of a transdiagnostic sample with dysfunctions in positive and negative valence processing. PRS for neuroticism may be correlated with current clinical symptoms due to the vulnerability to psychiatric disorders.

CONCLUSIONS

Greater genetic loading for neuroticism was associated with attenuated anticipatory responsiveness in reward/punishment processing with altered sensitivity to valences. Thus, a higher genetic risk for neuroticism may limit the degree to which positive and/or negative outcomes influence the current mood state, which may contribute to the development of positive and negative affective dysfunctions in individuals with mood, anxiety, and addictive disorders.

Neural and self-reported reward responsiveness are associated with dispositional affectivity and emotion dysregulation in adolescents with evidence for convergent and incremental validity

Adolescence is a developmental period characterized by heightened reward sensitivity which, in turn, confers risk for pertinent negative outcomes, underscoring the need to better understand biological bases and behavioral correlates of reward responsiveness during this developmental phase. Our goals in the current study were to examine, in a sample of 43 typically developing adolescents (M_age  = 15.67 years; SD = 1.01; 32.6% boys), (1) evidence of convergent validity between neural and self-report reward responsiveness, (2) associations between neural reward responsiveness and self-report dispositional affectivity and emotion dysregulation (ED) and (3) evidence of incremental validity of self-report beyond neural reward responsiveness in predicting affectivity and ED. During electroencephalography (EEG), adolescents completed two experimental paradigms probing event-related potential (ERP) indices of reward anticipation and initial responsiveness to reward attainment. Following EEG, they completed self-report measures of reward responsiveness, affectivity, and ED. Findings indicated some evidence of convergent validity between enhanced ERP indices of reward anticipation and initial response to reward and greater reinforcement sensitivity; that ERP indices of both reward responsiveness aspects predicted lower negative affectivity and less ED; and evidence of incremental validity of self-report beyond neural reward responsiveness in predicting outcomes. Results underscore the utility of a multi-method framework in assessing adolescent reward responsiveness and support the relevance of reward responsiveness in explaining individual differences in dispositional affectivity and ED.

Personality and psychopathology: In defense of a practical path toward integrating psychometric and biological approaches to advance a comprehensive model

Personality and psychopathology each reflect patterns of internal experience and outward behavior that differ between people and affect functioning. Drawing strict distinctions between the two concepts is not only difficult, but it may prove unnecessary for advancing an integrated model of psychological experiences associated with mental illness. We argue that developing such a model will be critical for improving treatment outcomes, and we discuss a practical path forward. Proponents of psychometric approaches to developing models of psychological experience focus on observable phenotypes and utilize statistical methods to describe patterns of covariation among a broad range of symptoms and dispositions. Advocates of biologically based approaches emphasize neuroscientific tools for identifying abnormalities in brain function that give rise to an individual's experience. There is substantial evidence that measures of personality and measures of symptoms capture nonoverlapping, clinically important information for understanding how and for whom treatments for mental illness work. In this article, we highlight the importance of combining psychometric and neurobiological approaches in order to understand which features of an individual those measures reflect, which aspects of neurobiology generate and maintain those features, how they relate to each other, and critically, how best to alter them to reduce distress and dysfunction.

From Description to Explanation: Integrating Across Multiple Levels of Analysis to Inform Neuroscientific Accounts of Dimensional Personality Pathology

Dimensional approaches to psychiatric nosology are rapidly transforming the way researchers and clinicians conceptualize personality pathology, leading to a growing interest in describing how individuals differ from one another. Yet, in order to successfully prevent and treat personality pathology, it is also necessary to explain the sources of these individual differences. The emerging field of personality neuroscience is well-positioned to guide the transition from description to explanation within personality pathology research. However, establishing comprehensive, mechanistic accounts of personality pathology will require personality neuroscientists to move beyond atheoretical studies that link trait differences to neural correlates without considering the algorithmic processes that are carried out by those correlates. We highlight some of the dangers we see in overpopulating personality neuroscience with brain-trait associational studies and offer a series of recommendations for personality neuroscientists seeking to build explanatory theories of personality pathology.

Developmental trajectories to reduced activation of positive valence systems: A review of biological and environmental contributions

Reduced activation of positive valence systems (PVS), including blunted neural and physiological responses to pleasant stimuli and rewards, has been shown to prospectively predict the development of psychopathology. Yet, little is known about how reduced PVS activation emerges across development or what implications it has for prevention. We review genetic, temperament, parenting, and naturalistic and laboratory stress research on neural measures of PVS and outline developmentally-informed models of trajectories of PVS activation. PVS function is partly heritable and appears to reflect individual differences in early-emerging temperament traits. Although lab-induced stressors blunt PVS activation, effects of parenting and naturalistic stress on PVS are mixed and depend on the type of stressor, developmental timing, and interactions amongst risk factors. We propose that there may be multiple, dynamic developmental trajectories to reduced PVS activation in which combinations of genes, temperament, and exposure to severe, prolonged, or uncontrollable stress may exert direct and interactive effects on PVS function. Critically, these risk factors may alter PVS developmental trajectories and/or PVS sensitivity to proximal stressors. Distinct factors may converge such that PVS activation proceeds along a typical, accelerated, chronically low, or stress-reactive trajectory. Finally, we present directions for future research with translational implications.

Associations Among Monoamine Neurotransmitter Pathways, Personality Traits, and Major Depressive Disorder

Major depressive disorder (MDD) is a complex psychiatric disease requiring multidisciplinary approaches to identify specific risk factors and establish more efficacious treatment strategies. Although the etiology and pathophysiology of MDD are not clear until these days, it is acknowledged that they are almost certainly multifactorial and comprehensive. Monoamine neurotransmitter system dysfunction and specific personality traits are independent risk factors for depression and suicide. These factors also demonstrate complex interactions that influence MDD pathogenesis and symptom expression. In this review, we assess these relationships with the aim of providing a reference for the development of precision medicine.

The relationship between neuroticism and appetitive conditioning

Appetitive conditioning is considered a central mechanism for the vulnerability to psychiatric disorders. However, the investigation of individual differences that are related to altered appetitive learning has been almost neglected so far. The aim of this study was to investigate the link between neuroticism and appetitive conditioning processes. 79 subjects participated in a differential conditioning procedure in which a conditioned stimulus (CS+) was paired with a reward (money) after a fast behavioral response, while a second conditioned stimulus (CS-) was never followed by a reward, irrespective of the behavioral response. As a main result, neuroticism correlated negatively with the underlying neural processes of appetitive conditioning in females, but not in males. In detail, higher levels of neuroticism were associated with decreased neural responses in the left (p = .001) and right amygdala (p = .011), left (p = .063) and right (p = .019) nucleus accumbens, and left (p = .002) and right (p = .021) orbitofrontal cortex (all results are family-wise-error-corrected). The present results support previous findings, which also showed an inverse sex-specific effect in the context of neuroticism and emotional processing in females. In addition, the findings suggest that neuroticism is not solely linked to increased amygdala sensitivity during the processing of negative stimuli but also to decreased neural responses when processing rewarding stimuli. Possible explanations for the sex differences and implications are discussed.

Neural Response to Rewards, Stress and Sleep Interact to Prospectively Predict Depressive Symptoms in Adolescent Girls

Blunted reward processing both characterizes major depressive disorder and predicts increases in depressive symptoms. However, little is known about the interaction between blunted reward processing and other risk factors in relation to increases in depressive symptoms. Stressful life events and sleep problems are prominent risk factors that contribute to the etiopathogenesis of depression and have been linked to reward dysfunction; these factors may interact with reward dysfunction to predict increased depressive symptoms. In a large sample of 8- to 14-year-old adolescent girls, the current study examined how blunted reward processing, stressful life events, and sleep problems at baseline interacted to predict increases in depressive symptoms 1 year later. Reward processing was indexed by the reward positivity (RewP), an event-related potential elicited during a simple monetary reward paradigm (i.e., Doors task). Two-way interactions confirmed that a blunted RewP predicted increased depressive symptoms at (a) high levels of stress but not average or low levels of stress, and (b) high and average levels of sleep problems but not low levels of sleep problems. Finally, a 3-way interaction confirmed that a blunted RewP predicted increased depressive symptoms at high levels of stress and sleep problems but not average or low levels of stress and sleep problems. Thus, adolescents characterized by low reward response (i.e., blunted RewP) were at an increased risk of developing depressive symptoms if they experienced increased stressful life events or sleep problems; moreover, risk was greatest among adolescents characterized by all 3.