Pupil Size Is Sensitive to Low-Level Stimulus Features, Independent of Arousal-Related Modulation.

ABSTRACT: Similar to a camera aperture, pupil size adjusts to the surrounding luminance. Unlike a camera, pupil size is additionally modulated both by stimulus properties and by cognitive processes, including attention and arousal, though the interdependence of these factors is unclear. We hypothesized that different stimulus properties interact to jointly modulate pupil size while remaining independent from the impact of arousal. We measured pupil responses from human observers to equiluminant stimuli during a demanding rapid serial visual presentation (RSVP) task at fixation and tested how response amplitude depends on contrast, spatial frequency, and reward level. We found that under constant luminance, unattended stimuli evoke responses that are separable from changes caused by general arousal o

SUBMITTER: Kim JH 

PROVIDER: S-EPMC10585606 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature