Article Figures & Data
Figures
- Figure 1.
Experiment 1: Effect of covertly attending to or directly fixating bright and dark disks. A, Stimulus display during a trial. B, Black and gray curves plot pupil diameter in the two conditions (attend to the dark/bright disk) as a function of time from trial onset, averaged across subjects after subtracting the pupil diameter in the 500 ms preceding the stimulus presentation. The blue curve plots the average difference between pupil responses in the two conditions; error bars are SEM. Lower traces plot average horizontal eye position, separately for trials where the attended stimulus (bright or dark, color coded) was presented in the right or left hemifield. Vertical lines mark the onset and offset of the disks (continuous) and the onset of the cue (dashed). C, D, Pupil diameter and horizontal eye position for experiments were subjects were instructed to look directly at the bright/dark disk (C) or attended to the fixation mark, which was displaced to elicit horizontal gaze shifts toward the bright or the dark disk (D, light gray and black traces, respectively).
- Figure 2.
Experiment 2: Effect of covertly attending to or directly fixating bright and dark gratings. A–D follow the same conventions as in Figure 1.
- Figure 3.
Experiment 3: Effect of covert attention to dark and bright disks in a delayed cue paradigm. A, Stimulus display. B, Same conventions as in Figure 1.
- Figure 4.
Experiment 4: Effect of covert attention as a function of stimulus intensity. A, B, The contrast of both disks was simultaneously manipulated (see icons) and attention was directed to the bright (A) or dark (B) disk. C, D, Only the bright (C) or the dark (D) disk was presented and subjects attended to the disk or the gray background on the opposite side of fixation. All conventions as in Figure 1.
