The ERPs to feedback indicating monetary loss and gain on the game of modified “rock-paper-scissors”

In many cases, emotional response follows cognitive appraisal to the results of one's own behavior. Using ERPs, we investigated the cognitive appraisal in evaluating the outcome of the gambling task. Larger feedback error related negativity (ERN) was elicited by lose and even conditions but not affected by the magnitude of bet. Larger P3 was elicited according to both the outcome and the size of the bet. Feedback ERN might reflect process of rapid evaluation of external events along expected/unexpected dimension but not good/bad dimension depending on the magnitude of reward or punishment.