Amygdala Grey Matter Volume and Face Activation Compared to Social Network Size

Abstract

Amygdala volume and face activation activity have been linked to social network size. In the current study, these relationships were examined through analysis of Magnetic Resonance Imaging and survey data of 116 subjects, with a more detailed analysis of a smaller sub-sample of 20 subjects. Amygdalae structural volumes were analyzed using Freesurfer, functional activation was analyzed using Statistical Parametric Mapping, and ultra-high-resolution susceptibility-weighted images were analyzed using in-house MATLAB scripts. Mean amygdala volumes obtained in this experiment are in line with those reported in previous research. Left amygdala volume was correlated with social network scores in males, and both left and right hippocampus volume were correlated with the square root of the size of one’s social network in females. Significant correlations were also observed between left amygdala face activation levels and social network measures in the smaller sub-sample (n = 20).