Early cortical response to behaviorally relevant absence of anticipated outcomes: a human event-related potential study.

Animals with lesions of the orbitofrontal cortex (OFC) have an extinction and reversal learning deficit. Humans with OFC lesions have similar deficits and often continue to act according to currently inappropriate memories. We tested when the human brain distinguishes between confirmed and negated outcomes of anticipations. Eleven participants predicted behind which one of two rectangles an object drawing was hidden while their cerebral activity was recorded from 123 surface electrodes. We found that absence of the predicted outcome induced specific electrical field topographies between 190 ms-300 ms and 380 ms-600 ms. Behaviorally irrelevant deviation from predicted outcomes did not induce these alterations. Distributed linear inverse solutions indicated that the source of the early electric field topography after negated predictions differed by additional left ventrolateral prefrontal activation. The late differences in electrical field topographies were characterized by the selective absence of a processing stage in response to negated predictions. The study indicates early, specific cortical processing of behaviorally relevant absence of predicted outcomes.