The structural and functional correlates underlying individual heterogeneity of reading the mind in the eyes.

Mentalizing is an essential component in human social interactions and the sources of individual variation in mentalizing are still very poorly understood. Utilizing the "reading the mind in the eyes" test (RMET), we examined the neuroanatomical basis of these differences with voxel-based morphometry and found that the gray matter density in the left posterior superior temporal sulcus (pSTS) could positively predict individuals' RMET scores. Furthermore, we found that the pSTS-amygdala functional connection was positively correlated to individuals' RMET scores. A test-validation procedure confirmed that the imaging results could be replicated and validated in another independent sample. Finally, mediation analysis revealed that pSTS-amygdala functional connection could account for the relationship between pSTS gray matter density and RMET scores. Present results demonstrate the contribution of brain structure of pSTS to individual variations in RMET performance and reveal an important implication of the neural circuit between core imitation and emotion regions in REMT.