Figure 1.

(A) Illustration of the saccade adaptation paradigm. At the beginning of a trial the eye is directed to a fixation point (X). Then, a saccade target (T₁) appears and the saccade is initiated. While the saccade is in flight, the target is displaced to a new position (T₂) in either outward or inward direction. (B) After several adaptation trials, the oculomotor system adapts to the intrasaccadic target displacement. The saccade now lands closer to the displaced position T₂ even though the saccade target is initially shown at position T₁. (C) lllustration of how visual mislocalization was measured. Subjects were asked to keep gaze fixated during the whole trial. Localization was measured in complete darkness. A probe stimulus (I) was briefly flashed and subjects indicated its apparent position with a mouse pointer. (D) Time course of saccade amplitude change (blue) and apparent probe location change (red) for outward adaptation. Error bars represent SEM. (E) Same for inward adaption. Error bars represent SEM. Data shown in (D,E) is replotted from Zimmermann and Lappe (2010).