Leshem R, Paoletti P, Piervincenzi C, Carducci F, Mallio C A, Errante Y, Quattrocchi C C, Ben-Soussan T Dotan
Department of Criminology, Bar-Ilan University, Ramat-Gan, Israel.
Research Institute for Neuroscience, Education and Didactics, Patrizio Paoletti Foundation, Neuroscientific Research Unit, Assisi, Italy.
Personal Neurosci. 2019 Sep 16;2:e6. doi: 10.1017/pen.2019.6. eCollection 2019.
The trait of extraversion is one of the longest-standing domains that captures the social dimension of personality and can potentially explain the covariation of a wide variety of behaviors. To date, there is a growing recognition that human behavior should be specified not only through the psychological mechanisms underlying each trait but also through their underlying neurobehavioral systems. While imaging studies have revealed important initial insights into the structural and functional neural correlates of extraversion, current knowledge about the relationships between extraversion and brain structures is still rather limited, especially with regard to the relationship between extraversion and white matter (WM). In this study, we aimed to investigate WM microstructure in extraversion in greater depth. Thirty-five healthy volunteers (21 women; mean age 35) underwent magnetic resonance imaging, as a part of a larger project aimed at investigating the longitudinal effect of motor training. WM integrity was assessed using the diffusion tensor imaging technique combining multiple diffusion tensor measures. Extraversion was assessed by the Eysenck Personality Questionnaire-Revised. Voxelwise correlation analyses between fractional anisotropy, axial diffusivities, and radial diffusivities maps and extraversion score showed decreased connectivity in the right inferior fronto-occipital fasciculus and forceps major among individuals who had high extraversion ratings. In conclusion, individual differences in extraversion may reflect differential organization of the WM tracts connecting frontal cortex, temporal, and occipital areas, which are related to socioemotional and control functions.
外向性特质是刻画人格社会维度的最持久的领域之一，并且可能解释多种行为的协变。迄今为止，人们越来越认识到，不仅应通过每种特质背后的心理机制，还应通过其潜在的神经行为系统来明确人类行为。虽然影像学研究已经对外向性的结构和功能神经关联有了重要的初步见解，但目前关于外向性与脑结构之间关系的知识仍然相当有限，尤其是在外向性与白质（WM）之间的关系方面。在本研究中，我们旨在更深入地探究外向性中的WM微观结构。35名健康志愿者（21名女性；平均年龄35岁）接受了磁共振成像，这是一个旨在研究运动训练纵向效应的更大项目的一部分。使用结合多种扩散张量测量的扩散张量成像技术评估WM完整性。通过艾森克人格问卷修订版评估外向性。分数各向异性、轴向扩散率和径向扩散率图与外向性得分之间的体素相关性分析显示，外向性评分高的个体右侧额枕下束和主要钳状体的连通性降低。总之，外向性的个体差异可能反映了连接额叶皮质、颞叶和枕叶区域的WM束的不同组织方式，这些区域与社会情感和控制功能有关。
