Figure 1.

(a) Diagram of screen appearance and timing during the downward adaptation trials for the two experiments. Trials in both experiments consisted of a fixation, which stepped to the left or right after a brief variable delay (900–1400 ms, of which only 400 ms was recorded). Diagram shows a rightward step example only. Upon saccade detection, a visual distractor was presented for 300 ms, after which it disappeared leaving only the target on the screen in the stepped location. An example of both types of distractors used in both experiments is shown (drawn approximately to scale). See text for a description of the full set of distractors used in each experiment. (b) A schematic of target, distractor, and eye position during an adaptation trial. After the target step, the eye follows with a saccade, upon which time a distractor is presented a short distance from the target, which remains at the stepped location for the remainder of the trial.