Human anterior cingulate cortex is activated by negative feedback: evidence from event-related potentials in a guessing task.

It has been controversially discussed whether the error-related negativity (ERN) or error negativity (N(e)), an electrophysiological index of anterior cingulate activation, reflects response conflict or response evaluation subserving error monitoring processes. We investigated event-related potentials (ERPs) in a guessing task which did not induce response conflict. Subjects had to guess which of the four aces of a French card play would be presented next and received feedback at random. We observed a negative ERP deflection in trials following negative feedback which was identified as ERN/N(e). Dipole analysis of scalp potentials indicated sources in the anterior cingulate and left inferior prefrontal cortex. The observation of the ERN/N(e) following negative feedback during guessing suggests that this ERP component mirrors response evaluation processes comparing expected and actual response outcome rather than response conflict.