title: S-cone discrimination for stimuli with spatial and temporal chromatic contrast.
abstract: In the natural environment, color discriminations are made within a rich context of spatial and temporal variation. In classical laboratory methods for studying chromatic discrimination, there is typically a border between the test and adapting fields that introduces a spatial chromatic contrast signal. Typically, the roles of spatial and temporal contrast on chromatic discrimination are not assessed in the laboratory approach. In this study, S-cone discrimination was measured using stimulus paradigms that controlled the level of spatio-temporal S-cone contrast between the tests and adapting fields. The results indicate that S-cone discrimination of chromaticity differences between a pedestal and adapting surround is equivalent for stimuli containing spatial, temporal or spatial-and-temporal chromatic contrast between the test field and the surround. For a stimulus condition that did not contain spatial or temporal contrast, the visual system adapted to the pedestal instead of the surround. The data are interpreted in terms of a model consistent with primate koniocellular pathway physiology. The paradigms provide an approach for studying the effects of spatial and temporal contrast on discrimination in natural scenes.
authors.affiliation: Visual Science Laboratories, Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: Dingcai
authors.initials: D
authors.lastname: Cao
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Zele
authors.forename: Vivianne C
authors.initials: VC
authors.lastname: Smith
authors.forename: Joel
authors.initials: J
authors.lastname: Pokorny
mesh_terms: D000328:Adult; D000818:Animals; D003118:Color Perception; D015350:Contrast Sensitivity; D004192:Discrimination, Psychological / Q000502:physiology*; D006801:Humans; D011323:Primates; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology*; D013028:Space Perception / Q000502:physiology; D013045:Species Specificity