Abstract

Although typically defined as the study of how people and groups interact, the field of social psychology comprises several disparate domains that make only indirect contributions to understanding interpersonal interaction, such as emotion, attitudes and the self. Although these various phenomena seem to have little in common, recent evidence indicates that the topics at the core of social psychology form a natural group of domains with a common functional neuroanatomy, centered on the medial prefrontal cortex. That self-referential, attitudinal, affective and other social phenomena converge on this region might reflect their shared reliance on inexact and internally generated estimates that differ from the more precise representations underlying other psychological phenomena. What is social psychology? A common definition of social psychology suggests that the field represents 'an attempt to understand and explain how the thought, feeling, and behavior of individuals are influenced by the actual, imagined, or implied presence of others' How have these intrapersonal topics emerged as the central province of social psychology, ostensibly the science of understanding humans in interpersonal contexts? Why instead have these topics not formed a core part of cognitive psychology, which explicitly attempts to model the mental operations that support other such within-person abilities such as perception, attention and memory? Moreover, why have several phenomena with clear implications for interpersonal behavior, such as face identification and language, become central pursuits within cognitive science while remaining comparatively peripheral to social psychology? Although a coherent sense of self, stable attitudes and a rich repertoire of emotional experience doubtlessly have vital roles in interpersonal interaction, it is unclear how they bear more directly on social behavior than some of the abilities that have been relatively neglected by social psychology. Over the past decade and a half, studies using neuroimaging and neuropsychological patients have provided a surprising but consistent answer to the question of what, if anything, binds these disparate topics within social psychology: a common neural basis. This work has demonstrated that four seemingly distinct cognitive phenomenathinking about oneself, accessing one's attitudes, the experience of emotion and inferring the contents of another person's mind -all converge on a single brain region, the medial prefrontal cortex (MPFC). Such observations suggest that contemporary social psychology, far from being a patchwork of unrelated research questions, is the science of a set of closely related phenomena with a common functional neuroanatomy. Indeed, the neural confluence of self, attitudes, emotional experience and mental state inference implies that these phenomena pose a common cognitive challenge to the human mind, met by a common processing solution MPFC contributions to 'social' phenomena Here, I review findings that suggest the ubiquity of MPFC involvement in four topics of central interest to social psychologists: the self-concept, attitudes and evaluation, emotional experience and understanding the minds of others. The goal is to provide an impressionistic -rather than exhaustive -overview of the surprising convergence of such 'social' abilities in the MPFC. Accordingly, discussion of other brain regions known to contribute to these phenomena is deferred (Box 1). Self-concept More than a dozen neuroimaging studies have examined the neural basis of the self-concept, as traditionally operationalized by social psychologists (Box 2), and these studies have ubiquitously linked self-referential processing to activity in MPFC