Stimulus valence influences the evaluative processing of action outcome.

The aim of the current study is to reveal the influence of prior associations between feedback stimuli and outcomes, in everyday life, on the early and late evaluative processing of outcomes. Participants were subjected to a simple gambling task while their electroencephalograms were recorded. Over two conditions, participants received congruent and incongruent feedback stimuli during the task. Feedback stimuli previously associated with positive outcomes were paired with monetary gain in the congruent condition and paired with monetary loss in the incongruent condition. We analyzed feedback-related negativity and P300 event-related brain potentials, as indices of early and late outcome evaluation. The results show that monetary loss, compared to gain, elicited larger feedback-related negativity, irrespective of congruency. However, the feedback-related negativity effect was delayed in the incongruent condition and an increased P300 amplitude was observed for congruent-loss outcomes. The valence of stimuli formed through experiences differently modulate early and late processes of outcome evaluation. The present study emphasizes the need to consider the stimulus valence to understand processes of outcome evaluation.