Inhibition of wrong responses and conflict resolution: an electroencephalogram study

To investigate the neural activity elicited by conflict processes, we recorded event-related potentials during a spatial version of the Simon task. In this task, participants have to release a key according to the direction of an arrow while ignoring the side on which this stimulus is presented. Responses are, nevertheless, faster when stimulus and response side match (spatial compatibility) than when they do not match (spatial incompatibility). Results showed that, in incompatible trials, a negative potential arising before response execution and corresponding to the N2 event-related potential component was elicited. The dipole analysis localized this potential to the anterior cingulate cortex. We suggest that this brain region is involved in the inhibition of incorrect responses in incompatible trials.