title: Perceived speed of colored stimuli.
abstract: The influence of contrast and color on perceived motion was measured using a speed-matching task. Observers adjusted the speed of an L cone contrast pattern to match that of a variety of colored test patterns. The dependence of speed on test contrast was the same for all test colors measured, differing only by a sensitivity factor. This result suggests that the reduced apparent speed of low contrast targets and certain colored targets is caused by a common cortical mechanism. The cone contrast levels that equate perceived speed differ substantially from those that equate visibility. This result suggests that the neural mechanisms governing speed perception and visibility differ. Perceived speed differences caused by variations in color can be explained by color responses that are characteristic of motion-selective cortex.
authors.affiliation: Department of Psychology, Stanford University, California 94305, USA. bobd@stanford.edu
authors.forename: R F
authors.initials: RF
authors.lastname: Dougherty
authors.forename: W A
authors.initials: WA
authors.lastname: Press
authors.forename: B A
authors.initials: BA
authors.lastname: Wandell
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D003116:Color; D003118:Color Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012684:Sensory Thresholds; D014793:Visual Cortex / Q000502:physiology*