title: A reinforcement learning mechanism responsible for the valuation of free choice.
abstract: Humans exhibit a preference for options they have freely chosen over equally valued options they have not; however, the neural mechanism that drives this bias and its functional significance have yet to be identified. Here, we propose a model in which choice biases arise due to amplified positive reward prediction errors associated with free choice. Using a novel variant of a probabilistic learning task, we show that choice biases are selective to options that are predominantly associated with positive outcomes. A polymorphism in DARPP-32, a gene linked to dopaminergic striatal plasticity and individual differences in reinforcement learning, was found to predict the effect of choice as a function of value. We propose that these choice biases are the behavioral byproduct of a credit assignment mechanism responsible for ensuring the effective delivery of dopaminergic reinforcement learning signals broadcast to the striatum.
authors: Department of Cognitive, Linguistic and Psychological Sciences, Brown Institute for Brain Science, Brown University, Providence, RI 02912, USA.
authors: Jeffrey
authors: J
authors: Cockburn
authors: Department of Cognitive, Linguistic and Psychological Sciences, Brown Institute for Brain Science, Brown University, Providence, RI 02912, USA.
authors: Anne G E
authors: AG
authors: Collins
authors: Department of Cognitive, Linguistic and Psychological Sciences, Brown Institute for Brain Science, Brown University, Providence, RI 02912, USA. Electronic address: michael_frank@brown.edu.
authors: Michael J
authors: MJ
authors: Frank
mesh_terms: D002755:Choice Behavior / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D004298:Dopamine / Q000378:metabolism; D006801:Humans; D007206:Individuality; D007858:Learning / Q000502:physiology*; D008960:Models, Psychological; D011597:Psychomotor Performance / Q000502:physiology; D012054:Reinforcement, Psychology; D012201:Reward
chemical_list: D004298:Dopamine