Identity-Specific Reward Representations in Orbitofrontal Cortex Are Modulated by Selective Devaluation.
Goal-directed behavior is sensitive to the current value of expected outcomes. This requires independent representations of specific rewards, which have been linked to orbitofrontal cortex (OFC) function. However, the mechanisms by which the human brain updates specific goals on the fly, and translates those updates into choices, have remained unknown. Here we implemented selective devaluation of appetizing food odors in combination with pattern-based neuroimaging and a decision-making task. We found that in a hungry state, participants chose to smell high-intensity versions of two value-matched food odor rewards. After eating a meal corresponding to one of the two odors, participants switched choices toward the low intensity of the sated odor but continued to choose the high intensity of the nonsated odor. This sensory-specific behavioral effect was mirrored by pattern-based changes in fMRI signal in lateral posterior OFC, where specific reward identity representations were altered after the meal for the sated food odor but retained for the nonsated counterpart. In addition, changes in functional connectivity between the OFC and general value coding in ventromedial prefrontal cortex (vmPFC) predicted individual differences in satiety-related choice behavior. These findings demonstrate how flexible representations of specific rewards in the OFC are updated by devaluation, and how functional connections to vmPFC reflect the current value of outcomes and guide goal-directed behavior.SIGNIFICANCE STATEMENTThe orbitofrontal cortex (OFC) is critical for goal-directed behavior. A recent proposal is that OFC fulfills this function by representing a variety of state and task variables ("cognitive maps"), including a conjunction of expected reward identity and value. Here we tested how identity-specific representations of food odor reward are updated by satiety. We found that fMRI pattern-based signatures of reward identity in lateral posterior OFC were modulated after selective devaluation, and that connectivity between this region and general value coding ventromedial prefrontal cortex (vmPFC) predicted choice behavior. These results provide evidence for a mechanism by which devaluation modulates a cognitive map of expected reward in OFC and thereby alters general value signals in vmPFC to guide goal-directed behavior.
Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611.
James D
JD
Howard
Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611 thorsten.kahnt@northwestern.edu.
Thorsten
T
Kahnt
D000328:Adult; D059031:Anticipation, Psychological / Q000502:physiology*; D001069:Appetite Regulation / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology*; D025461:Feedback, Physiological / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D017397:Prefrontal Cortex / Q000502:physiology*; D012201:Reward; D013647:Task Performance and Analysis; D055815:Young Adult
decision making; devaluation; fMRI; olfaction; orbitofrontal cortex; reward