Fig. 1

Task design and staircase result. (A) Trial example. Subjects were instructed to look at a fixation point (FP) for at least 500 ms at the beginning of each trial. Then, a stream of pink noise stimuli would be presented on both sides of the FP and remain on the screen until the end of the trial. After a random period of 500–900 ms, a saccadic cue (black line) would indicate the side where a saccade should be executed. After an SOA of \(\sim\)142 ms, a visual target (filtered pink noise) with a clockwise (CW) or counterclockwise (CCW) orientation would appear either on the left or right side of the screen for 50 ms. Subjects had to discriminate the orientation of the target at the end of the trial. (B) Stimuli eccentricities and sizes. (C–F) Example of the staircase procedure applied separately for each stimulus eccentricity. Target contrast is shown in function of the number of trials. Each staircase subplot shows the subject’s performance for cue towards (red) and away (gray) from the target. Filled and open dots represent correct and incorrect discrimination responses, respectively. On the right, the mean and standard error (SEM) for each condition are shown. The mean was calculated using the means of the posterior distribution given by the staircase procedure.