Speed discrimination thresholds for first--and second-order bars and edges.
Speed discrimination thresholds were measured for first- and second-order Gaussian bars and edges as a function of speed and the spatial scale of the modulation signal. Discrimination thresholds were generally higher for the second-order patterns when compared with modulations of luminance. There were no systematic effects of variations in the width of the bars and edges. The results are discussed in relation to mechanisms for the explicit recovery of contrast modulations and the influence of the form of the carrier signal on visual performance in second-order motion tasks.
Johnston
A
A
Department of Psychology, University College London, U.K. alan@psychol.ucl.ac.uk
Benton
C P
CP
D015350:Contrast Sensitivity / Q000502:physiology; D006801:Humans; D008027:Light; D009039:Motion Perception / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology*