Figure 1
A) Each trial started with a central fixation point on a gray background. After a delay, there was a presentation of a target stimulus, and after a random delay the central fixation point disappeared and participants were required to move their eyes to the target. During the delay period, the two patch stimuli were presented briefly (400 ms), with the bright/dark patch being spatially aligned with the target location in the bright/dark condition, respectively. Neither patches were aligned with the target location in the neutral condition. B) Memory-delay task was similar to the visual-delay task except the target stimulus was only presented briefly (400 ms).
Figure 2
Effect of saccade planning on the local luminance modulation. Saccadic behaviors on different patch conditions on the visual-delay task (n = 19) (A) Saccade accuracy. (B) Saccade reaction times. (C) Change in pupil diameter following the presentation of patch stimuli in different conditions. (D) Pupil size in diameter (200 to 800 ms) between bright and dark patch conditions for each individual participant. In A, B, the error-bars represent ± standard error across participants. In C, the shaded colored regions surrounding the pupillary response represent ± standard error range (across participants) for different conditions. The black bar on X-axis indicates the time line of patch presentation, and the cyan bar on X-axis indicates the time line at which differences between the bright and dark conditions were statistically significant (p < 0.05). The 200–800 ms epoch after the patch onset is shaded in gray. n: number of participants. SRT: saccade reaction times.
Figure 3
Effect of spatial working memory on the local luminance modulation. Saccadic behaviors on different patch conditions on the memory-delay task (n = 17) (A) Saccade accuracy. (B) Saccade reaction times. (C) Change in pupil diameter following the presentation of patch stimuli in different conditions. (D) Pupil size in diameter (200 to 800 ms) between bright and dark patch conditions for each individual participant. In A, B, the error-bars represent ± standard error across participants. * indicates the differences were statistically significant (p < 0.05). In C, the shaded colored regions surrounding the pupillary response represent ± standard error range (across participants) for different conditions. The black bar on X-axis indicates the time line of patch presentation, and the cyan bar on X-axis indicates the time line at which differences between the bright and dark conditions were statistically significant (p < 0.05). The 200–800 ms epoch after the patch onset is shaded in gray. n: number of participants. SRT: saccade reaction times.
Figure 4
Comparison between saccade planning and working memory effects on the local luminance modulation. (A) Differences in pupil size between the bright and dark condition in visual-delay and memory-delay saccade tasks (n = 17). (B) The mean pupil size at epoch A (200 to 800 ms) and B (1950 to 2000 ms). In A, the shaded colored regions surrounding the pupillary response represent ± standard error range (across participants) for different tasks. The black bar on X-axis indicates the time line of patch presentation. n: number of participants.
Figure 5
Arousal effect on the local luminance modulation between two tasks. Change in pupil diameter following the presentation of patch stimuli in different conditions in the visual-delay saccade task (n = 17) in larger baseline (–50 to 0 ms) pupil velocity (A), or smaller baseline pupil velocity (B). Change in pupil diameter following the presentation of patch stimuli in different conditions in the memory-delay saccade task (n = 17) in larger baseline (–50 to 0 ms) pupil velocity (D), or smaller baseline pupil velocity (E). (C) Pupil size in diameter (600 to 800 ms) between bright and dark patch conditions as a function of task (visual-delay and memory-delay) and baseline pupil velocity (larger and smaller). (F) Baseline pupil velocity (–50 to 0 ms) between bright and dark patch conditions as a function of task (visual-delay and memory-delay) and baseline pupil velocity (larger and smaller). In A, B, D, E, the shaded colored regions surrounding the pupillary response represent ± standard error range (across participants) for different conditions. The black bar on X-axis indicates the time line of patch presentation, and the cyan bar on X-axis indicates the time line at which differences between the bright and dark conditions were statistically significant (p < 0.05). n: number of participants. Difference: differences between the bright and dark conditions. PuVel: pupil velocity. Visual: visual-delay task. Memory: memory-delay task.
Figure 6
Local luminance modulation with no contingency between patch and target location. (A) Change in pupil diameter following the presentation of patch stimuli in different conditions in visual-delay saccade task. (B) Pupil size in diameter (200 to 800 ms) between bright and dark patch conditions for each individual participant on the visual-delay saccade task (n = 6). (C) Change in pupil diameter following the presentation of patch stimuli in different conditions in memory-delay saccade task. (D) Pupil size in diameter (200 to 800 ms) between bright and dark patch conditions for each individual participant on the memory-delay saccade task (n = 10). In A, C, the shaded colored regions surrounding the pupillary response represent ± standard error range (across participants) for different conditions. The black bar on X-axis indicates the time line of patch presentation. In D, circles indicate the data collected in the experiment with 8 possible target locations whereas squares indicate the data collected in the experiment with 16 possible target locations. n: number of participants.