Medial prefrontal cell activity signaling prediction errors of action values.

To adapt behavior to a changing environment, one must monitor outcomes of executed actions and adjust subsequent actions accordingly. Involvement of the medial frontal cortex in performance monitoring has been suggested, but little is known about neural processes that link performance monitoring to performance adjustment. Here, we recorded from neurons in the medial prefrontal cortex of monkeys learning arbitrary action-outcome contingencies. Some cells preferentially responded to positive visual feedback stimuli and others to negative feedback stimuli. The magnitude of responses to positive feedback stimuli decreased over the course of behavioral adaptation, in correlation with decreases in the amount of prediction error of action values. Therefore, these responses in medial prefrontal cells may signal the direction and amount of error in prediction of values of executed actions to specify the adjustment in subsequent action selections.