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A Comparison of Reward‐Contingent Neuronal Activity in Monkey Orbitofrontal Cortex and Ventral Striatum
Author(s) -
SIMMONS JANINE M.,
RAVEL SABRINA,
SHIDARA MUNETAKA,
RICHMOND BARRY J.
Publication year - 2007
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1196/annals.1401.028
Subject(s) - orbitofrontal cortex , ventral striatum , neuroscience , striatum , psychology , reward system , prefrontal cortex , dopamine , cognition
: We have investigated how neuronal activity in the orbitofrontal‐ventral striatal circuit is related to reward‐directed behavior by comparing activity in these two regions during a visually guided reward schedule task. When a set of visual cues provides information about reward contingency, that is, about whether or not a trial will be rewarded, significant subpopulations of neurons in both orbitofrontal cortex and ventral striatum encode this information. Orbitofrontal and ventral striatal neurons also differentiate between rewarding and non‐rewarding trial outcomes, whether or not those outcomes were predicted. The size of the neuronal subpopulation encoding reward contingency is twice as large in orbitofrontal cortex (50% of neurons) as in ventral striatum (26%). Reward‐contingency‐dependent activity also appears earlier during a trial in orbitofrontal cortex than in ventral striatum. The peak reward‐contingency representation in orbitofrontal cortex (31% of neurons), occurs during the wait period, a period of high anticipation prior to any action. The peak ventral striatal representation of reward contingency (18%) occurs during the go period, a time of action. We speculate that signals from orbitofrontal cortex bias ventral striatal activity, and that a flow of reward‐contingency information from orbitofrontal cortex to ventral striatum serves to guide actions toward rewards.