title: Crowding in the S-cone pathway.
abstract: The spatial extent of interference from nearby object or contours (the critical spacing of "crowding") has been thoroughly characterized across the visual field, typically using high contrast achromatic stimuli. However, attempts to link this measure with known properties of physiological pathways have been inconclusive. The S-cone pathway, with its ease of psychophysical isolation and known anatomical characteristics, offers a unique tool to gain additional insights into crowding. In this study, we measured the spatial extent of crowding in the S-cone pathway at several retinal locations using a chromatic adaptation paradigm. S-cone crowding was evident and extensive, but its spatial extent changed less markedly as a function of retinal eccentricity than the extent found using traditional achromatic stimuli. However, the spatial extent agreed with that of low contrast achromatic stimuli matched for isolated resolvability. This suggests that common cortical mechanisms mediate the crowding effect in the S-cone and achromatic pathway, but contrast is an important factor. The low contrast of S-cone stimuli makes S-cone vision more acuity-limited than crowding-limited.
authors.affiliation: Vision Science Graduate Group, University of California, Berkeley, United States. Electronic address: dan.coates@ppw.kuleuven.be.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Coates
authors.affiliation: Vision Science Graduate Group, University of California, Berkeley, United States; School of Optometry, University of California, Berkeley, United States.
authors.forename: Susana T L
authors.initials: STL
authors.lastname: Chung
mesh_terms: D000293:Adolescent; D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult
keywords: Critical spacing; Crowding; Peripheral acuity; S-cone pathway