title: With you or against you: social orientation dependent learning signals guide actions made for others.
abstract: In social environments, it is crucial that decision-makers take account of the impact of their actions not only for oneself, but also on other social agents. Previous work has identified neural signals in the striatum encoding value-based prediction errors for outcomes to oneself; also, recent work suggests that neural activity in prefrontal cortex may similarly encode value-based prediction errors related to outcomes to others. However, prior work also indicates that social valuations are not isomorphic, with social value orientations of decision-makers ranging on a cooperative to competitive continuum; this variation has not been examined within social learning environments. Here, we combine a computational model of learning with functional neuroimaging to examine how individual differences in orientation impact neural mechanisms underlying 'other-value' learning. Across four experimental conditions, reinforcement learning signals for other-value were identified in medial prefrontal cortex, and were distinct from self-value learning signals identified in striatum. Critically, the magnitude and direction of the other-value learning signal depended strongly on an individual's cooperative or competitive orientation toward others. These data indicate that social decisions are guided by a social orientation-dependent learning system that is computationally similar but anatomically distinct from self-value learning. The sensitivity of the medial prefrontal learning signal to social preferences suggests a mechanism linking such preferences to biases in social actions and highlights the importance of incorporating heterogeneous social predispositions in neurocomputational models of social behavior.
authors.affiliation: Virginia Tech Carilion Research Institute, 2, Riverside Circle, Roanoke, VA 24016, USA; Nanyang Business School, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
authors.forename: George I
authors.initials: GI
authors.lastname: Christopoulos
authors.affiliation: Virginia Tech Carilion Research Institute, 2, Riverside Circle, Roanoke, VA 24016, USA; Department of Psychology, Virginia Tech, Blacksburg, VA, USA; Department of Psychiatry, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA; Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences, Blacksburg, VA, USA; Research Service Line, Salem VA Medical Center, Salem, VA, USA. Electronic address: bkcasas@vt.edu.
authors.forename: Brooks
authors.initials: B
authors.lastname: King-Casas
mesh_terms: D000328:Adult; D003198:Computer Simulation; D003342:Corpus Striatum / Q000502:physiology*; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D007858:Learning / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D017397:Prefrontal Cortex / Q000502:physiology*; D012054:Reinforcement, Psychology; D012938:Social Perception; D012945:Social Values
keywords: Prediction error; Reward learning; Social neuroscience; Social orientation; Social value orientation; fMRI