Neural correlates of social perception: The posterior superior temporal sulcus is modulated by action rationality, but not animacy

Recent research has investigated the neural basis of social perception, the ability to make high-level social inferences from perceptual information. The right posterior superior temporal sulcus (pSTS) has been identified as a candidate region for this ability, but the specific processes to which the pSTS contributes remain unclear. In the present study, we investigated the neural correlates of social perception using simple animated geometric shape stimuli, separately manipulating the perceived animacy, goal-directedness, and path rationality in the animations. We did not find an increased pSTS response to animate or goal-directed animations. However, we found that across conditions, the pSTS response tracked path rationality, with stronger responses to irrational paths. This is consistent with prior neuroimaging research on the perception of human actions, and supports the claim that the pSTS is involved in action understanding.