The correlation between brain gray matter volume and empathizing and systemizing quotients in healthy children.

The abilities to empathize and to systemize, two fundamental dimensions of cognitive style, are characterized by apparent individual differences. These abilities are typically measured using an empathizing quotient (EQ) and a systemizing quotient (SQ) questionnaire, respectively. The purpose of this study was to reveal any correlations between EQ and SQ scores and regional gray matter volumes in healthy children by applying voxel-based morphometry to magnetic resonance images. We collected MRIs of brain structure and administered children's versions of the EQ and SQ questionnaires (EQ-C and SQ-C, respectively) to 261 healthy children aged 5-15 years. Structural MRI data were segmented, normalized, and smoothed using an optimized voxel-based morphometric analysis. Next, we analyzed the correlation between regional gray matter volume and EQ-C and SQ-C scores adjusting for age, sex, and intracranial volume. The EQ-C scores showed significant positive correlations with the regional gray matter volumes of the left fronto-opercular and superior temporal cortices, including the precentral gyrus, the inferior frontal gyrus, the superior temporal gyrus, and the insula, which are functionally related to empathic processing. Additionally, SQ-C scores showed a significant negative correlation with the regional gray matter volume of the left posterior parietal cortex, which is functionally involved in selective attention processing. Our findings suggest that individual differences in cognitive style pertaining to empathizing or systemizing abilities could be explained by differences in the volume of brain structures that are functionally relevant to empathizing and systemizing.