Figure 1.

(A) Setup used in all experiments. Stimuli were presented on a red background. The fixation point (black rectangle) was displayed 19° to the left of the screen center, and the probe dot (green disk) in one of four different positions. Subjects saccaded to the center of the screen, either following the presentation of a visually saccade target or with no saccade target. After saccade execution a mouse cursor appeared with which subjects localized the perceived probe-dot position. (B) Timecourse of events in the “target-on” saccade task. The trial started with a fixation point 19° to the left of screen center. After a variable time between 1300 and 1500 ms, the saccade target was presented for the rest of the trial and the fixation point disappeared. Subjects then saccaded to the saccade target. A probe dot was flashed for 8 ms at various times around saccade onset. (C) Timecourse of events in the “no-target” condition. The fixation point is shown for a variable time between 1300 and 1500 ms. Subjects made a saccade into the middle of the screen when the fixation point was switched off. A probe dot was flashed for 8 ms at various times around saccade onset. (D) Timecourse of events in the “no-target” condition. The fixation point is shown for a variable time between 1300 and 1500 ms. Subjects made a saccade into the first quarter of the screen (−10°) when the fixation point was switched off. One hundred milliseconds before offset of the fixation point, a reference object was presented in one of three possible locations and remained on screen. A probe dot was flashed for 8 ms at various times around saccade onset.