title: Dissociable saccadic suppression of pupillary and perceptual responses to light.
abstract: We measured pupillary constrictions in response to full-screen flashes of variable luminance, occurring either at the onset of a saccadic eye movement or well before/after it. A large fraction of perisaccadic flashes were undetectable to the subjects, consistent with saccadic suppression of visual sensitivity. Likewise, pupillary responses to perisaccadic flashes were strongly suppressed. However, the two phenomena appear to be dissociable. Across subjects and luminance levels of the flash stimulus, there were cases in which conscious perception of the flash was completely depleted yet the pupillary response was clearly present, as well as cases in which the opposite occurred. On one hand, the fact that pupillary light responses are subject to saccadic suppression reinforces evidence that this is not a simple reflex but depends on the integration of retinal illumination with complex "extraretinal" cues. On the other hand, the relative independence of pupillary and perceptual responses suggests that suppression acts separately on these systems-consistent with the idea of multiple visual pathways that are differentially affected by saccades.
authors.affiliation: Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy; Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Florence, Italy; and.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Benedetto
authors.affiliation: Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy; CNR, Institute of Neuroscience, Pisa, Italy p.binda1@in.cnr.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Binda
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D009119:Muscle Contraction; D011680:Pupil / Q000502:physiology*; D012025:Reflex, Pupillary; D012438:Saccades; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception
keywords: parallel visual pathways; perisaccadic suppression; pupil; pupillary light reflex; saccadic eye movements; vision for action