Figure 1.

Search-step task. All trials began after a variable fixation length. In no-step trials, a red target was presented among seven green distractors and the participant was instructed to look as quickly as possible to the target. On follow trials, two red targets were presented simultaneously among six green distractors and the participant was instructed to look at each of the targets one after the other (order was irrelevant). On redirect trials, a red target was presented among green distractors. At some delay after the array presentation (TSD), the red target reappeared at a new location in the array and the old location became a distractor. Participants were instructed to inhibit the gaze shift to the old target location and look immediately at the new location of the target. Trials in which participants were successful in looking immediately at the new target location were referred to as compensated, and trials in which the participant erroneously looked first toward the old location of the target were referred to as noncompensated. The probability of correctly compensating becomes more difficult with longer TSDs; therefore, TSD was dynamically altered using a staircase procedure to ensure ∼50% accuracy on redirect trials.