Detecting perceptual conflict by the feedback-related negativity in brain potentials.

The feedback-related negativity (FRN) in brain potentials is typically observed for the outcome evaluation concerning one's performance or monetary reward. Using a task in which the participant guesses whether the first stimulus (S1) would have the same color as the subsequently presented second stimulus (S2), this study demonstrates that the FRN to S2, which serves as feedback to the guessing, is also sensitive to the conflict between perceptual representations of S1 and S2 in working memory. The FRN effect for the feedback concerning the correctness of one's performance is modulated by the congruency between perceptual properties of the stimuli. The anterior cingulate cortex, which generates the FRN, is thus a general conflict-monitoring device detecting both response and perceptual conflicts.