Relationship between extraversion personality and gray matter volume and functional connectivity density in healthy young adults: an fMRI study

Neural correlates of neuroticism: A coordinate-based meta-analysis of resting-state functional brain imaging studies

Neuroticism is one of the most robust higher-order personality traits associated with negative emotionality and risk of mental disorders. Many studies have investigated relationships between neuroticism and the brain, but the results have been inconsistent. We conducted a meta-analysis of whole-brain resting-state functional neuroimaging studies to identify the most stable neurofunctional substrates of neuroticism. We found stable significant positive correlations between neuroticism and resting-state brain activity in the left middle temporal gyrus (MTG), left striatum, and right hippocampus. In contrast, resting-state brain activity in the left superior temporal gyrus (STG) and right supramarginal gyrus (SMG) was negatively associated with neuroticism. Additionally, meta-regression analysis revealed brain regions in which sex and age moderated the link of spontaneous activity with neuroticism. This is the first study to provide a comprehensive understanding of resting-state brain activity correlates of neuroticism, and the findings may be useful for the targeting of specific brain regions for interventions to decrease the risks of mental health problems.

“Nothing to see here”: No structural brain differences as a function of the Big Five personality traits from a systematic review and meta-analysis

Personality reflects social, affective, and cognitive predispositions that emerge from genetic and environmental influences. Contemporary personality theories conceptualize a Big Five Model of personality based on the traits of neuroticism, extraversion, agreeableness, conscientiousness, and openness to experience. Starting around the turn of the millennium, neuroimaging studies began to investigate functional and structural brain features associated with these traits. Here, we present the first study to systematically evaluate the entire published literature of the association between the Big Five traits and three different measures of brain structure. Qualitative results were highly heterogeneous, and a quantitative meta-analysis did not produce any replicable results. The present study provides a comprehensive evaluation of the literature and its limitations, including sample heterogeneity, Big Five personality instruments, structural image data acquisition, processing, and analytic strategies, and the heterogeneous nature of personality and brain structures. We propose to rethink the biological basis of personality traits and identify ways in which the field of personality neuroscience can be strengthened in its methodological rigor and replicability.

Gray matter structures associated with neuroticism: A meta-analysis of whole-brain voxel-based morphometry studies

Neuroticism is major higher-order personality trait and has been robustly associated with mental and physical health outcomes. Although a growing body of studies have identified neurostructural markers of neuroticism, the results remained highly inconsistent. To characterize robust associations between neuroticism and variations in gray matter (GM) structures, the present meta-analysis investigated the concurrence across voxel-based morphometry (VBM) studies using the anisotropic effect size signed differential mapping (AES-SDM). A total of 13 studies comprising 2,278 healthy subjects (1,275 females, 29.20 ± 14.17 years old) were included. Our analysis revealed that neuroticism was consistently associated with the GM structure of a cluster spanning the bilateral dorsal anterior cingulate cortex and extending to the adjacent medial prefrontal cortex (dACC/mPFC). Meta-regression analyses indicated that the neuroticism-GM associations were not confounded by age and gender. Overall, our study is the first whole-brain meta-analysis exploring the brain structural correlates of neuroticism, and the findings may have implications for the intervention of high-neuroticism individuals, who are at risk of mental disorders, by targeting the dACC/mPFC.

Common and distinct brain functional alterations in pharmacotherapy treatment-naïve female borderline personality disorder patients with and without auditory verbal hallucinations: a pilot study

Auditory verbal hallucinations (AVHs) are experienced by approximately 25% of patients with borderline personality disorder (BPD). Despite the high incidence, the pathological features of AVH in BPD remain unclear. This study aimed to investigate whole-brain functional connectivity (FC), as measured by functional connectivity density (FCD), and its relationship with AVH in BPD. 65 pharmacotherapy treatment-naïve female BPD patients (30 with AVH and 35 without AVH), and 35 female healthy controls were investigated. Functional magnetic resonance imaging (fMRI) data were collected to assess whole-brain FC and functional connectivity density mapping (FCDM) was applied to the fMRI data to compute FCD features. Compared to the healthy controls, both BPD groups (BPD-AVH and BPD without AVH) exhibited significantly higher gFCD values in the bilateral prefrontal lobe, bilateral orbital lobule, and bilateral insula, and significantly lower gFCD values in the SMA, right anterior temporal lobule, and the ACC. These altered regions were significantly associated with AVH in the BPD subjects. Moreover, higher gFCD values were observed in the left posterior temporal lobule and posterior frontal lobule. Aberrant alterations also emerged in the left posterior temporal lobule and posterior frontal lobule, mainly in Broca and Wernicke regions. Nevertheless, there was no significant correlation between gFCD values and the severity of AVH as measured by the AVH scores. In summary, we have identified aberrations in the FC and brain metabolism of the aforementioned neural circuits/networks, which may provide new insights into BPD-AVH and facilitate the development of therapeutic approaches for treating AVH in BPD patients.

Neurostructural correlates of optimism: Gray matter density in the putamen predicts dispositional optimism in late adolescence

Dispositional optimism reflects one's generalized positive expectancies for future outcomes and plays a crucial role in personal developmental outcomes and health (e.g., counteracting related mental disorders such as depression and anxiety). Increasing evidence has suggested that extraversion is an important personality factor contributing to dispositional optimism. However, less is known about the association between dispositional optimism and brain structure and the role of extraversion in this association. Here, we examined these issues in 231 healthy high school students aged 16 to 20 years (110 males, mean age = 18.48 years, SD = 0.54) by estimating regional gray matter density (rGMD) using a voxel-based morphometry method via structural magnetic resonance imaging. Whole-brain regression analyses revealed a significant positive correlation between dispositional optimism and the rGMD of the bilateral putamen after adjusting for age, sex, family socioeconomic status (SES), general intelligence, and total gray matter volume (TGMV). Moreover, prediction analyses using fourfold balanced cross-validation combined with linear regression confirmed a significant connection between dispositional optimism and putamen density after adjusting for age, sex, and family SES. More importantly, subsequent mediation analysis showed that extraversion may account for the association between putamen density and dispositional optimism after adjusting for age, sex, family SES, general intelligence, TGMV, and the other four Big Five personality traits. Taken together, the current study provides new evidence regarding the neurostructural basis underlying dispositional optimism in adolescents and underscores the importance of extraversion as an essential personality factor for dispositional optimism acquisition.

Personality Factors' Impact on the Structural Integrity of Mentalizing Network in Old Age: A Combined PET-MRI Study

The mentalizing network (MN) treats social interactions based on our understanding of other people's intentions and includes the medial prefrontal cortex (mPFC), temporoparietal junction (TPJ), posterior cingulate cortex (PCC), precuneus (PC), and amygdala. Not all elders are equally affected by the aging-related decrease of mentalizing abilities. Personality has recently emerged as a strong determinant of functional connectivity in MN areas. However, its impact on volumetric changes across the MN in brain aging is still unknown. To address this issue, we explored the determinants of volume decrease in MN components including amyloid burden, personality, and APOE genotyping in a previously established cohort of 130 healthy elders with a mean follow-up of 54 months. Personality was assessed with the Neuroticism Extraversion Openness Personality Inventory-Revised. Regression models corrected for multiple comparisons were used to identify predictors of volume loss including time, age, sex, personality, amyloid load, presence of APOE epsilon 4 allele, and cognitive evolution. In cases with higher Agreeableness scores, there were lower volume losses in PCC, PC, and amygdala bilaterally. This was also the case for the right mPFC in elders displaying lower Agreeableness and Conscientiousness. In multiple regression models, the effect of Agreeableness was still observed in left PC and right amygdala and that of Conscientiousness was still observed in right mPFC volume loss (26.3% of variability, significant age and sex). Several Agreeableness (Modesty) and Conscientiousness (order, dutifulness, achievement striving, and self-discipline) facets were positively related to increased volume loss in cortical components of the MN. In conclusion, these data challenge the beneficial role of higher levels of Agreeableness and Conscientiousness in old age, showing that they are associated with an increased rate of volume loss within the MN.

Treatment of auditory verbal hallucinations with atypical antipsychotics in healthy individuals: an artificially controlled post-treatment report

OBJECTIVE

This study was performed to investigate the effects and associated global functional connectivity density (gFCD) alterations associated with the use of atypical antipsychotics in healthy individuals with auditory verbal hallucinations (Hi-AVHs) using gFCD mapping techniques.

METHODS

A magnetic resonance imaging database of 38 Hi-AVHs with chronic or severe AVH symptoms was generated. The Hi-AVHs were administered an atypical antipsychotic (risperidone) for 24 weeks and monitored for a treatment response. All patients underwent functional magnetic resonance imaging pre- and post-treatment.

RESULTS

gFCD alterations were found in the auditory-memory-language and visual circuit regions pre- and post-treatment. However, gFCD alterations differed between patients with strong and weak treatment responses.

CONCLUSION

This is the first report to show that atypical antipsychotics can improve the symptoms of AVHs and that the treatment effects are associated with gFCD alterations in the auditory-memory-language circuit. These findings provide a foundation for future exploration of new treatment strategies for Hi-AVHs.

Brain gray matter correlates of extraversion: A systematic review and meta-analysis of voxel-based morphometry studies

Extraversion is a fundamental personality dimension closely related to an individual's life outcomes and mental health. Although an increasing number of studies have attempted to identify the neurostructural markers of extraversion, the results have been highly inconsistent. The current study aimed to achieve a comprehensive understanding of brain gray matter (GM) correlates of extraversion with a systematic review and meta-analysis approach. Our review showed relatively high interstudy heterogeneity among previous findings. Our meta-analysis of whole-brain voxel-based morphometry studies revealed that extraversion was stably associated with six core brain regions. Additionally, meta-regression analyses identified brain regions where the associations of extraversion with GM volume were modulated by gender and age. The relationships between extraversion and GM structures were discussed based on three extraversion-related functional systems. Furthermore, we explained the gender and age effects. Overall, our study is the first to reveal a comprehensive picture of brain GM correlates of extraversion, and the findings may be useful for the selection of targeted brain areas for extraversion interventions.