THE TIME-COURSE OF BRAIN ACTIVATIONS DURING RESPONSE-INHIBITION - EVIDENCE FROM EVENT-RELATED POTENTIALS IN A GO NO GO TASK

THE cortical organization of executive control was investigated using event-related potentials (ERPs). ERPs were collected while subjects pe rformed a go/no go task that required response inhibition. First, arou nd 260 ms after stimulus onset, an effect of response inhibition on ER Ps was observed over inferior prefrontal areas. Generators in these re gions were confirmed by source analysis. Later, between 300-600 ms aft er stimulus onset, a left lateralized fronto-central ERP effect was fo und which differed in topography from a non-specific effect of task di fficulty. Source analysis indicated that generators in anterior cingul ate and left premotor areas also contributed to this effect. Orchestra ted activation of prefrontal areas and the anterior cingulate subserve s executive function whereas relatively late activity of the left prem otor cortex is involved in motor control.