Trials began with a fixation array (upper panel) 500 ms. The small white dots to the left and right of fixation denoted where a target could appear. The target array (middle panels) was then presented for 75 ms. Observers were instructed to discriminate the orientation of the clock-face appearing over the placeholder. On 50% of trials, only the target was presented (“uncrowded” trials, not shown). On the remaining 50% of trials the target was flanked by two distractors. When present, these distractors were rotated ±60, 90, or 120°. At the end of each trial a randomly oriented probe was rendered at the same location as the target (bottom panel); observers adjusted the orientation of this stimulus until it matched their percept of the target's orientation.