The ERN was found to have a frontomedial generator in the cortex, and further investigations implicated the anterior cingulate cortex (ACC) in its generation. A related ERP component known as the feedback error-related negativity (fERN or FRN) was observed upon presentation of negative feedback regarding the outcome of a trial. This led to the hypothesis that the cingulate cortex serves as a nonspecific error-detection center (Miltner, Braun, & Coles, 1997).