Temporal course of cognitive control in a picture-word interference task.

The neural correlates of cognitive control in a picture-word interference task were investigated in 13 healthy individuals using event-related potentials. The differences between the incongruent condition and the congruent condition were examined. Behavioral data showed that the task yielded a robust interference effect as indexed by a longer reaction time for the incongruent condition. Scalp event-related potential analysis revealed greater negative differences in N300 and N570 in the incongruent compared with the congruent condition. The results showed that there may be two cognitive control phases during conflict resolution in a picture-word interference task. N300 is a critical sign of conflict monitoring in the primitive stage, whereas N570 embodies the response conflict in the terminal stage.