BRAIN BASIS OF HUMAN SOCIAL INTERACTION: NEUROCOGNITIVE FUNCTIONS AND META-ANALYSIS

Abstract

Social interactions, or the reciprocal exchange between socially engaged individuals, plays a central role in shaping human life. Social interactions are fundamental for neurocognitive development, and a key factor contributing to mental and physical health. Despite their importance, research investigating the neurocognitive systems associated with human social interaction is relatively new. Human neuroimaging research has traditionally used approaches that separate the individual from social contexts, thereby limiting the ability to examine brain systems underlying interactive social behavior. More recent work has begun incorporating real-time social contexts, and have implicated an extended network of brain regions associated with social interaction. However, open questions remain about the neurocognitive processes that are critical for social interactions and the brain systems that are commonly engaged. The current dissertation aims to address these gaps in our understanding through a set of studies using computational and data-driven approaches. Study 1 examined the relationship between social interaction and mentalizing, which is the ability to infer the mental states of others that is considered to be critically important for social interactions. Prior work has demonstrated that mentalizing and social interaction elicit brain activity spatially overlapping areas, but spatial overlap is not necessarily indicative of a common underlying process. Thus, Study 1 utilized multivariate approaches to examine the similarity of brain activity patterns associated with mentalizing outside of social contexts and when interacting with a peer (regardless of mentalizing) as a means for inferring a functional relationship between the two. Study 2 investigated brain regions commonly engaged across social interactive contexts using coordinate-based meta-analysis, which is an approach for aggregating findings across neuroimaging literature. This involved an exhaustive search strategy to find fMRI and PET studies that utilize social interactive approaches, and calculated spatial convergence across studies as a means to uncover brain regions that are reliably implicated during social interaction. The results from Studies 1 and 2 offer major advancements for a neuroscientific understanding of social interaction by demonstrating a functional link with mentalizing and through elucidating brain systems that are commonly reported in studies using social interactive approaches.