Project Summary Humans live in large social groups. The requirements of living in such groups may have led to the evolution of language and as well as larger brains. Underpinning our superior social skills is a vast storehouse of social knowledge. For instance, our ability to recognize other individuals and retrieve information about who they are, what their relationship is to us, their position in a social hierarchy, even their personality traits, all relies on a social brain that is tightly linked to declarative memory systems. In addition, our ability to understand and engage in mentalizing, our use of stereotypes and categories, the application of socio-cultural norms about status, hierarchy, and etiquette, as well as the ability to understand the intent, rather than the concrete meaning, of speech, all rely heavily on stored knowledge. Here we propose to extend our prior work that identified a flexible circuit that allows us to retrieve different types of person knowledge, with a putative person identity node in the anterior temporal lobe (ATL) at the center of it. We will use multivariate fMRI and representational similarity analysis, as well as structural and functional connectivity analyses, to examine the flexible interaction of this region with perceptual systems, episodic memory systems, and the greater social brain. Success in this project will significantly advance our understanding of the basic neural mechanisms that contribute to high-level social processing and will have important clinical implications for disorders that have core social knowledge deficits such as autism spectrum disorder and schizophrenia.