Representation of Action-Specific Reward Values in the Striatum

TLDR

The estimation of the reward an action will yield is critical in decision‑making. The study aimed to elucidate the role of the basal ganglia in action‑reward estimation. Neuronal activity was recorded from the striatum of monkeys performing left or right handle‑turn choices guided by action‑specific reward probabilities. During the pre‑choice delay, more than one‑third of striatal projection neurons encoded the value of one action, while fewer encoded relative values or choice, suggesting that action‑specific reward values are represented in the striatum to guide basal‑ganglia action selection.

Abstract

The estimation of the reward an action will yield is critical in decision-making. To elucidate the role of the basal ganglia in this process, we recorded striatal neurons of monkeys who chose between left and right handle turns, based on the estimated reward probabilities of the actions. During a delay period before the choices, the activity of more than one-third of striatal projection neurons was selective to the values of one of the two actions. Fewer neurons were tuned to relative values or action choice. These results suggest representation of action values in the striatum, which can guide action selection in the basal ganglia circuit.