Fig. 2.

(A) Positions of the fixation point (FP) and the saccade target (T1) for the adaptation procedure. During execution of the saccade, the saccade target jumped in the outward direction. (B) Positions of the fixation point and the saccade targets (T1 and T2) in the “spatiotopic condition.” Subjects fixated on the fixation point until saccade target T1 appeared and then made a saccade to T1. From T1 they had to initiate a saccade to T2. (C) Effect of adaptation on the amplitude of the horizontal saccadic vector of the second saccade in the double-step sequence, expressed as the difference in average amplitude before and after adaptation. Error bars represent the standard error of the sample mean. Adaptation occurs in the spatiotopic (and full) conditions, but not in the retinotopic conditions. (D) Effect of head-turn on adaptation-induced horizontal saccade amplitude changes of the second saccade in the double-step sequence. Horizontal saccades were adapted with the head facing the screen center, and test trials were collected with the head turned 9_ leftward (purple) or rightward (orange). The adaptation remained spatiotopic with head turns. Error bars represent the standard error of the sample mean. (E) Mean shift in saccade landing position for the 3 overlap durations during adaptation in the spatiotopic condition. Shifts of saccades performed to targets presented for 50 ms are shown in blue, and shifts of saccades performed to targets presented for 500 ms are shown in red. Error bars represent SE. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of the article.)