A role for contrast-normalisation in second-order motion perception.
Two low-level motion models are applied to a second-order stimulus, a translating contrast modulation of static binary noise. Both models have been used to demonstrate equivalence between energy and gradient algorithms and can be split into a motion-opponent stage followed by a contrast-normalised stage. Analysis of results shows no directional bias at the motion-opponent stage but a strong bias, indicating the correct direction of second-order motion, at the contrast-normalised stage. This demonstrates that the intrinsically non-linear process of contrast-normalisation may play a part in the detection of second-order motion.
Benton
Christopher P
CP
Department of Experimental Psychology, University of Bristol, 8 Woodland Road, Bristol BS8 1TN, UK. chris.benton@bristol.ac.uk
D000465:Algorithms; D015350:Contrast Sensitivity / Q000502:physiology*; D004056:Differential Threshold / Q000502:physiology; D006801:Humans; D008960:Models, Psychological; D009039:Motion Perception / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D012107:Research Design