title: Representation of economic preferences in the structure and function of the amygdala and prefrontal cortex.
abstract: Social value orientations (SVOs) are economic preferences for the distribution of resources - prosocial individuals are more cooperative and egalitarian than are proselfs. Despite the social and economic implications of SVOs, no systematic studies have examined their neural correlates. We investigated the amygdala and dorsolateral prefrontal cortex (DLPFC) structures and functions in prosocials and proselfs by functional magnetic resonance imaging and evaluated cooperative behavior in the Prisoner's Dilemma game. We found for the first time that amygdala volume was larger in prosocials and positively correlated with cooperation, while DLPFC volume was larger in proselfs and negatively correlated with cooperation. Proselfs' decisions were marked by strong DLPFC and weak amygdala activity, and prosocials' decisions were marked by strong amygdala activity, with the DLPFC signal increasing only in defection. Our findings suggest that proselfs' decisions are controlled by DLPFC-mediated deliberative processes, while prosocials' decisions are initially guided by automatic amygdala processes.
authors.affiliation: Graduate School of International Corporate Strategy, Hitotsubashi University, Tokyo, 101-8439 Japan.
authors.forename: Alan S R
authors.initials: AS
authors.lastname: Fermin
authors.affiliation: Graduate School of International Corporate Strategy, Hitotsubashi University, Tokyo, 101-8439 Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Sakagami
authors.affiliation: Brain Science Institute, Tamagawa University, Machida, 194-8620 Japan.
authors.forename: Toko
authors.initials: T
authors.lastname: Kiyonari
authors.affiliation: Graduate School of International Corporate Strategy, Hitotsubashi University, Tokyo, 101-8439 Japan.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Graduate School of International Corporate Strategy, Hitotsubashi University, Tokyo, 101-8439 Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Matsumoto
authors.affiliation: School of Social Informatics, Aoyama Gakuin University, Sagamihara, 252-0206 Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Yamagishi
mesh_terms: D000679:Amygdala / Q000502:physiology*; D003657:Decision Making; D060909:Economics, Behavioral; D006801:Humans; D008279:Magnetic Resonance Imaging; D009042:Motivation / Q000502:physiology; D010551:Personality / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology*; D012919:Social Behavior; D012945:Social Values