A reinforcement learning mechanism responsible for the valuation of free choice

Neuron. 2014 Aug 6;83(3):551-7. doi: 10.1016/j.neuron.2014.06.035. Epub 2014 Jul 24.


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.

MeSH terms

  • Choice Behavior / physiology*
  • Cognition / physiology
  • Dopamine / metabolism
  • Humans
  • Individuality
  • Learning / physiology*
  • Models, Psychological
  • Psychomotor Performance / physiology
  • Reinforcement, Psychology*
  • Reward


  • Dopamine