"Where did I go wrong?" A psychophysiological analysis of error detection.

There is a component of the event-related brain potential, the error-related negativity (or ERN), that is related to error detection in choice reaction time tasks. The J. Miller (1982) paradigm was used to determine whether the detection process manifested by the ERN involves a comparison between representations of the actual response and the correct response or between representations of the stimulus anticipated by the subject and the stimulus that actually occurs. The data favored the former rather than the latter kind of comparison, with the magnitude of the error signal depending on the similarity or dissimilarity between the two response representations. In turn, response similarity depended on the strategy used by the subjects to select responses: Response parameters selected first defined which responses would be most similar.