White matter structures associated with emotional intelligence: evidence from diffusion tensor imaging.

Previous studies of brain lesions, functional activity, and gray matter structures have suggested that emotional intelligence (EI) is associated with regions involved in the network of social cognition (SCN) and in somatic marker circuitry (SMC). Our new study is the first to investigate the association between white matter (WM) integrity and EI. We examined this relationship in the brain of healthy young adult men [n = 74, mean age = 21.5 years, standard deviation (SD) = 1.6] and women (n = 44, mean age = 21.9 years, SD = 1.4). We performed a voxel-based analysis of fractional anisotropy, which is an indicator of WM integrity, using diffusion tensor imaging and used a questionnaire (EI Scale) for measuring EI to identify the correlation of WM integrity with individual EI factor (intrapersonal, interpersonal, and situation management factors). Our results showed that (a) the intrapersonal factor of EI was positively correlated with WM integrity in the right anterior insula, and (b) the interpersonal factor of EI was associated with WM integrity in a part of the right inferior longitudinal fasciculus (ILF). The right anterior insula is one of the important nodes of the SMC, whereas the ILF connects the visual cortex and areas related to SCN, and thus, is a part of the SCN. Our findings further support the notion that the brain regions involved in the SCN and in the SMC are associated with EI.