title: Own-gender imitation activates the brain's reward circuitry.
abstract: Imitation is an important component of human social learning throughout life. Theoretical models and empirical data from anthropology and psychology suggest that people tend to imitate self-similar individuals, and that such imitation biases increase the adaptive value (e.g., self-relevance) of learned information. It is unclear, however, what neural mechanisms underlie people's tendency to imitate those similar to themselves. We focused on the own-gender imitation bias, a pervasive bias thought to be important for gender identity development. While undergoing fMRI, participants imitated own- and other-gender actors performing novel, meaningless hand signs; as control conditions, they also simply observed such actions and viewed still portraits of the same actors. Only the ventral and dorsal striatum, orbitofrontal cortex and amygdala were more active when imitating own- compared to other-gender individuals. A Bayesian analysis of the BrainMap neuroimaging database demonstrated that the striatal region preferentially activated by own-gender imitation is selectively activated by classical reward tasks in the literature. Taken together, these findings reveal a neurobiological mechanism associated with the own-gender imitation bias and demonstrate a novel role of reward-processing neural structures in social behavior.
authors.affiliation: UCLA Interdepartmental Neuroscience Program, Ahmanson-Lovelace Brain Mapping Center, Room 237, 660 Charles E. Young Drive South, Los Angeles, CA 90095-7085, USA. ereynol@ucla.edu
authors.forename: Elizabeth A Reynolds
authors.initials: EA
authors.lastname: Losin
authors.forename: Macro
authors.initials: M
authors.lastname: Iacoboni
authors.forename: Alia
authors.initials: A
authors.lastname: Martin
authors.forename: Mirella
authors.initials: M
authors.lastname: Dapretto
mesh_terms: D000328:Adult; D001499:Bayes Theorem; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D005783:Gender Identity; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007100:Imitative Behavior / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012201:Reward; D055815:Young Adult