Social motivation has been conceptualized as a fundamental drive in humans. Impairments in social motivation have been postulated to be a core social deficit in autism spectrum disorders (ASDs). However, despite the fundamental role that our desire for social interactions plays in developing and maintaining relationships, little is known about neural mechanisms underlying this social drive. One can consider the enhanced motivation to seek social interaction following deprivation a form of craving, similar to cravings for food when hungry or for drugs in abstaining addicts.
Rebecca Saxe’s laboratory proposes to test the hypothesis that activity in the dopaminergic midbrain after acute isolation is correlated with social craving in humans, homologous to findings previously observed in mice1. The experimental design will follow the procedure previously used in mice as closely as possible. Specifically, socially connected and extroverted, typically developing human adults will be acutely socially isolated, followed by behavioral and neural tests of social craving. Measures of social craving in humans will be modeled on cue-induced craving paradigms typically used in studies of food and drug craving in humans. Thus, the Saxe laboratory can directly test whether activity in midbrain regions (assessed by functional magnetic resonance imaging) is selectively correlated with the subjective feeling of craving social contact and not simply with generalized motivation. Demonstrating that humans show this activation of dopaminergic midbrain regions in response to social craving will validate the utility of the mouse model for future testing of mechanisms of altered social motivation in ASD.