The role of outcome expectations in the generation of the feedback-related negativity.

The feedback-related negativity (FRN) is thought to index activity within the midbrain dopaminergic reward-learning system, with larger FRN magnitudes observed when outcomes are worse than expected. This view holds that the FRN is an index of neural activity coding for prediction errors, and reflects activity that can be used to adaptively alter future performance. Untested to date, however, is a key prediction of this view: the FRN should not appear in response to negative outcomes when outcome expectations are not allowed to develop. The current study tests this assumption by eliciting FRNs to win and loss feedback in conditions of participant choice, participant observation of computer choice, and, critically, simple presentation of win or loss feedback in the absence of a predictive choice cue. Whereas FRNs were observed in each of the conditions in which there was time for an expectation to develop, no FRN was observed in conditions without sufficient time for the development of an expectation. These results provide empirical support for an untested but central tenet of the reinforcement learning account of the genesis of the FRN.