title: Pre-exposure to contrast selectively compresses the achromatic half-axes of color space.
abstract: The gamut of perceived colors can be represented in a space with bright-dark, red-green and blue-yellow axes. Pre-exposure to a field that changes periodically over time in luminance or along one of the color axes reduces vividness of colors along the entire axis [Webster and Mollon (1991) Nature, 349, 235-238]. But is it possible to reduce vividness or perceived contrast selectively for half-axes in color space? We assessed such selective compression of the bright-dark axis using a task where subjects matched tests in a pre-adapted region to ones in an un-adapted region. Tests were bright or dark pinstripes on a gray background, and pre-exposure was to multiple drifting pinstripes. Matches made after pre-exposure indicate a combination of symmetric and asymmetric compression, with more compression when adapting and test stimulus were similar in contrast polarity.
authors.affiliation: Department of Psychology, University of California at San Diego, 92093-0109, La Jolla, CA, USA.
authors.forename: R D
authors.initials: RD
authors.lastname: Beer
authors.forename: D I
authors.initials: DI
authors.lastname: MacLeod
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology; D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology*; D006801:Humans; D014795:Visual Pathways / Q000502:physiology