Human luminance pattern-vision mechanisms: masking experiments require a new model.
A widely used model of simultaneous luminance pattern masking is based on mechanisms that sum inputs linearly and produce a response that is an S-shaped function of that sum. This model makes two predictions about masking: (1) Changing the masker spatial waveform will shift the threshold-versus-masker contrast function horizontally by a multiplicative constant. (2) Adding a second fixed-contrast masker will shift this function horizontally by an additive constant. Experimental tests do not support these predictions. The results can be explained by a new model that incorporates broadband divisive inhibition, consistent with physiology.
Foley
J M
JM
Department of Psychology, University of California, Santa Barbara 93106.
D015350:Contrast Sensitivity; D006801:Humans; D008027:Light; D008433:Mathematics; D008954:Models, Biological; D009949:Orientation; D010364:Pattern Recognition, Visual / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*