Fig. 1.

Sample stimuli used in the control and flanker tasks. On control trials, a single red chevron pointed either left or right. These trials provided baseline response times. Four kinds of flanker trials were presented. On go trials, a central red chevron was flanked by four red diamonds, two on each side. On no-go trials, the chevron was flanked by four red Xs. On congruent trials, distractor chevrons pointed in the same direction as the target red chevron. On incongruent trials, distractor chevrons pointed in the opposite direction as the target red chevron.