A common and specialized neural code for social attention triggered by eye gaze and biological motion

Humans appear to be endowed with the ability to readily share attention with interactive partners through the utilization of social direction cues, such as eye gaze and biological motion (BM). Here, we investigated the specialized brain mechanism underlying this fundamental social attention ability by incorporating different types of social (i.e., BM, gaze) and non-social (arrow) cues and combining functional magnetic resonance imaging (fMRI) with a modified central cueing paradigm. Using multi-voxel pattern analysis (MVPA), we found that although gaze- and BM-mediated attentional orienting could be decoded from neural activity in a wide range of brain areas, only the right anterior and posterior superior temporal sulcus (aSTS and pSTS) could specifically decode attentional orienting triggered by social but not non-social cues. Critically, cross-category MVPA further revealed that social attention could be decoded across BM and gaze cues in the right STS and the right superior temporal gyrus (STG). However, these regions could not decode attentional orienting across social and non-social cues. These findings together provide evidence for the existence of a specialized social attention module in the human brain, with the right STS/STG being the critical neural site dedicated to social attention.