Wang, Y.; Davidow, J. Y.; Lane, R. D.; Satpute, A. B.

While much research in social cognitive neuroscience has focused on which brain regions are engaged when processing social content, it remains unclear what these areas are doing in terms of underlying mechanisms. Here, we approached this question using predictive processing theory, which suggests that the brain instantiates a generative model of its sensory environment. Using a novel animated shapes fMRI task, we observed a functional double dissociation between brain regions that were engaged when forming a prediction for agentic movement - which involved the premotor cortex and the lateral parietal cortex, previously implicated in action observation and mirroring - from those associated with processing feedback for updating abstract priors to guide predictions - which involved the dorsomedial and ventrolateral prefrontal cortex, the temporoparietal area, and the lateral temporal cortex, previously associated with mentalizing/theory of mind. We observed parallel functional dissociations in the cerebellar areas affiliated with these networks. These findings suggest new insights into how brain regions associated with action observation/mirroring and mentalizing/theory of mind play complementary roles in supporting facets of a predictive processing architecture underlying social cognition.