Ventral frontal cortex in children: morphology, social cognition and femininity/masculinity

Abstract

The ventral frontal cortex (VFC) has been shown to differ morphologically between sexes. Social cognition, which many studies demonstrate involves the VFC, also differs between sexes, with females being more adept than males. In a previous study of subregions of the VFC in our lab, in an adult population, size of the straight gyrus (SG) but not the orbitofrontal cortex (OFC), differed between sexes and correlated with better performance on a test of social cognition and with greater identification with feminine characteristics. To investigate the relationship between VFC structure and social cognition in children, VFC gray matter volumes were measured on MRIs from 37 boys and 37 girls aged 7 to 17. The VFC was subdivided into the OFC and SG. Subjects were also administered a test of social perceptiveness and a rating scale of femininity/masculinity. In contrast to our findings in adults, the SG was slightly smaller in girls than boys. In girls, but not boys, smaller SG volumes significantly correlated with better social perception and higher identification with feminine traits. No volume differences by sex or significant correlations were found with the OFC. These data suggest a complex relationship between femininity, social cognition and SG morphology.

Fig. 1

The orbitofrontal cortex and straight gyrus. (A) ventral, (B) lateral and (C) medial views of the orbitofrontal cortex (purple) and straight gyrus (blue).

Fig. 2

Age-related differences between sexes in the straight gyrus. (A) Scatterplot of total straight gyrus volume vs age with linear regression fit lines for boys (solid line) and girls (dashed line). (B) The orbitofrontal cortex shown for comparison.