Adapted from Moran et al. (2024). a, Stimulus dimensions and configuration. Left, Stimuli were sinusoidal gratings (diameter, 8 dva) presented at 5.05 dva from a fixation point. Stimuli extended across the foveal and parafoveal regions. Right, Participants always fixated on the black fixation point and made a saccade when cued by a gradual color change to white. Stimuli were presented around fixation on fixation trials (Locations 1–4; black) or around the white fixation point/saccade target on control trials and saccade trials, respectively (Locations 5–8; orange). The red circle around the black fixation point indicates eye position. The numbers on the screen indicate all possible stimulus presentation locations. b, In fixation trials, participants maintained fixation on the black fixation target (shown here with a red ring to indicate the position of the eyes) throughout the trial, never fixating on the white. Approximately 400–800 ms after trial onset, the grating stimulus was presented at one of four locations around fixation at either a low or high SF. The stimulus was displayed for 100 ms. In control trials, participants fixated on the black fixation point. A grating stimulus was presented at one of four locations around the alternate fixation point (white circle). c, In saccade trials, participants fixated on the black fixation point. After 200–600 ms, the black fixation point changed to white and the white fixation point changed to black, which served as the saccade cue. The colors gradually changed over a period of 1.2 s, indicated here by the color gradient. The light gray bar behind the gradient refers to the possible start/end times of the color change. In a period ranging from 400 to 100 ms before saccade onset, a grating stimulus was presented at one of four locations around the current fixation (“central saccade trials”—not analyzed) or the saccade target (“peripheral saccade trials”). The stimulus was presented for 100 ms. The light gray bar behind the dark gray bar refers to the possible start/end times of the stimulus.
