Lower dorsal striatum activation in association with neuroticism during the acceptance of unfair offers.

Unfair treatment may evoke more negative emotions in individuals scoring higher on neuroticism, thereby possibly impacting their decision-making in these situations. To investigate the neural basis of social decision-making in these individuals, we examined interpersonal reactions to unfairness in the Ultimatum Game (UG). We measured brain activation with fMRI in 120 participants selected based on their neuroticism score, while they made decisions to accept or reject proposals that were either fair or unfair. The anterior insula and anterior cingulate cortex were more activated during the processing of unfair offers, consistent with prior UG studies. Furthermore, we found more activation in parietal and temporal regions for the two most common decisions (fair accept and unfair reject), involving areas related to perceptual decision-making. Conversely, during the decision to accept unfair offers, individuals recruited more frontal regions previously associated with decision-making and the implementation of reappraisal in the UG. High compared to low neurotic individuals did not show differential activation patterns during the proposal of unfair offers; however, they did show lower activation in the right dorsal striatum (putamen) during the acceptance of unfair offers. This brain region has been involved in the formation of stimulus-action-reward associations and motivation/arousal. In conclusion, the findings suggest that both high and low neurotic individuals recruit brain regions signaling social norm violations in response to unfair offers. However, when it comes to decision-making, it seems that neural circuitry related to reward and motivation is altered in individuals scoring higher on neuroticism, when accepting an unfair offer.

The neural correlates of worry in association with individual differences in neuroticism.

The tendency to worry is a facet of neuroticism that has been shown to mediate the relationship between neuroticism and symptoms of depression and anxiety. The aim of the current study was to investigate the neural correlates of state worry in association with neuroticism. One-hundred twenty participants were selected from an initially recruited sample of 240 women based on their neuroticism score. First, participants completed a questionnaire to assess the excessiveness and uncontrollability of pathological worry. Second, we measured brain activation with functional magnetic resonance imaging (fMRI) while participants were randomly presented with 12 worry-inducing sentences and 12 neutral sentences in a mood induction paradigm. Individuals scoring higher on neuroticism reported to worry more in daily life and to have generated more worry-related thoughts after the presentation of a worry-inducing sentence. Furthermore, imaging results showed the involvement of default mode and emotional brain areas during worry, previously associated with self-related processing and emotion regulation. Specifically, cortical midline structures and the anterior insula showed more activation during worry, when individuals indicated to have generated more worry-related thoughts. Activation in the retrosplenial and visual cortex was decreased in individuals scoring higher on neuroticism during worry, possibly suggesting reduced autobiographical specificity and visual mental imagery. In the literature, both these processes have been related to the cognitive avoidance of emotional distress. Excessive worry features in a number of emotional disorders and results from studies that elucidate its neural basis may help explain how and why neuroticism contributes to vulnerability for psychopathology.

The effect of criticism on functional brain connectivity and associations with neuroticism.

Neuroticism is a robust personality trait that constitutes a risk factor for psychopathology, especially anxiety disorders and depression. High neurotic individuals tend to be more self-critical and are overly sensitive to criticism by others. Hence, we used a novel resting-state paradigm to investigate the effect of criticism on functional brain connectivity and associations with neuroticism. Forty-eight participants completed the NEO Personality Inventory Revised (NEO-PI-R) to assess neuroticism. Next, we recorded resting state functional magnetic resonance imaging (rsfMRI) during two sessions. We manipulated the second session before scanning by presenting three standardized critical remarks through headphones, in which the subject was urged to please lie still in the scanner. A seed-based functional connectivity method and subsequent clustering were used to analyse the resting state data. Based on the reviewed literature related to criticism, we selected brain regions associated with self-reflective processing and stress-regulation as regions of interest. The findings showed enhanced functional connectivity between the clustered seed regions and brain areas involved in emotion processing and social cognition during the processing of criticism. Concurrently, functional connectivity was reduced between these clusters and brain structures related to the default mode network and higher-order cognitive control. Furthermore, individuals scoring higher on neuroticism showed altered functional connectivity between the clustered seed regions and brain areas involved in the appraisal, expression and regulation of negative emotions. These results may suggest that the criticized person is attempting to understand the beliefs, perceptions and feelings of the critic in order to facilitate flexible and adaptive social behavior. Furthermore, multiple aspects of emotion processing were found to be affected in individuals scoring higher on neuroticism during the processing of criticism, which may increase their sensitivity to negative social-evaluation.