Habits and dopamine

July 2025

Abstract

Instrumental conditioning is thought to engage two forms of action control: when an action is first learned, its performance is most flexible and sensitive to both its relationship to and the value of its immediate consequences. With practice, actions can become inflexible, with their performance governed more by antecedent stimuli than their consequences—they become habits. The acquisition of habits depends on an association between specific stimuli (S) and the behavioral response (R), a bond that is strengthened by a process of reinforcement and that involves dopamine. Here, we emphasize the psychological complexities around this association and map these onto the corticostriatal plasticity processes that current evidence suggests support S-R learning at microscopic and mesoscopic levels. Based on this evidence, we develop the perspective that the implementation of habits in neural circuits is determined by shifting sources of dopamine: one bound to prediction errors and another to motor execution.