Bottom-up and generative computations uniquely explain neural responses across the social brain

The ability to recognize social interactions between others is central to humans' daily lives and engages brain regions supporting social perception and mental state inference. The neural computations underlying this ability, however, are poorly understood. Here we leveraged new models of bottom-up social perception and generative social inference to test the hypothesis that these complementary computations are carried out in separate brain regions. We compared both models to brain responses from subjects viewing procedurally generated videos of social interactions. Surprisingly, we found that both models explained neural activity in both perceptual and mentalizing regions, even when controlling for effects of the other model. These findings challenge the idea of a strict division of labor in the social brain and refine our understanding of the computations supporting human social inference.