Dysfunction of the superior occipital gyrus in individuals with subclinical social anxiety and its mediating effect on gray matter structure.

The investigation of neuroimaging abnormalities of young adults with subclinical social anxiety will contribute to understand the brain mechanism of social anxiety during developing on early stage. In this study, we recruited twenty-six young adults with subclinical social anxiety and matched healthy controls to examine their resting-state brain functional changes reflected by amplitude of low-frequency fluctuation (ALFF), functional connectivity (FC) and effective connectivity (EC). Mediating effect models were used to investigate the mediation of brain functional alterations between gray matter structure and social anxiety. Subjects with subclinical social anxiety exhibited increased ALFF in the left superior occipital gyrus (SOG), heightened FC between the left SOG and the right orbital part inferior frontal gyrus, decreased EC from the left SOG to bilateral postcentral gyrus (PCG), and increased EC from bilateral PCG and the right precuneus to the left SOG. A complete mediating effect of gray matter volume in the left SOG on subclinical social anxiety through ALFF in the left SOG was observed. In conclusion, dysfunction of the left SOG plays an important role in subclinical social anxiety. Additionally, the spontaneous neural hyperactivities in the left SOG function on social anxiety as a complete mediation of gray matter structure.