Injection of a dopamine type 2 receptor antagonist into the dorsal striatum disrupts choices driven by previous outcomes, but not perceptual inference

Authors

• E Lee
• O Dal Monte
• BB Averbeck

Abstract

Decisions are based on a combination of immediate perception and previous experience. If the mapping between actions and outcomes in a context is unpredictable over time, decisions must be made on the basis of immediately available information. Alternatively, if action-outcome mappings can be learned by reinforcement, then this information can be combined with immediately available information. Previous neurophysiological results suggest that frontal-striatal circuits may be involved in the interaction between these processes. The role of dopamine, however, has not been examined directly. We injected locally dopamine type 1 (D1A; SCH23390) or type 2 (D2A; Eticlopride) antagonists or saline into the dorsal striatum while macaques performed an oculomotor sequential decision making task. Choices in the task were driven by perceptual inference and/or reinforcement of past choices. We found that the D2A affected decisions based on previous outcomes. When we fit Rescorla-Wagner models, the inverse temperature decreased after D2A injections into the dorsal striatum compared with a pre-injection period. We found that neither the D1A nor saline injections affected behavior. Overall, our results suggest D2Rs in the striatum control the inverse temperature in reinforcement learning.

Scientific Focus Area: Neuroscience

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