Distinct influence of inter- versus intra-trial feedback on the brain response to subsequent feedback: Evidence from event-related potentials

Substantial evidence indicates that feedback processing not only varies with the valence of feedback, but is also highly dependent on contextual factors. Even so, the influence of prior outcome history on current outcome evaluation is far from clear. To investigate this issue, we conducted two event-related potential (ERP) experiments using a modified gambling task whereby each trial was associated with two consequences. In experiment 1, two instances of feedback indicated participant performance on two dimensions of a single decision, within a trial. In experiment 2, participants made two decisions in each trial, and then received two instances of feedback. We examined the feedback-related negativity (FRN) as an index of feedback processing. When both instances of feedback were relevant to the same trial (intra-trial), the FRN to the second was affected by the valence of the immediately previous feedback: The FRN was amplified to losses following wins. This was observed in both experiment 1 and experiment 2. When two instances of feedback were relevant to two different trials (inter-trial), the effect of immediately previous feedback on the FRN was inconsistent. In experiment 1 there was no effect of feedback from the previous trial on the FRN. However, in Experiment 2 there was an effect of inter-trial feedback on the FRN that was opposite to the effect of intra-trial feedback: The FRN was amplified when losses followed losses. Taken together, the findings suggest that the neural systems involved in reward processing dynamically and continuously integrate preceding feedback for the evaluation of present feedback.