Masking effects of low-frequency sinusoidal gratings on the detection of contrast modulation in high-frequency carriers

A modification and extension of Kortum and Geisler's model Vision Res. 35, 1595 (1995)] of early visual non-linearities that incorporates an expansive nonlinearity (consistent with neurophysiological findings Vision Res. 35, 2725 (1995)], a normalization based on a local average retinal illumination, similar to Mach's proposal F. Ratliff, Mach Bands: Quantitative Studies on Neural Networks in the Retina (Holden-Day, San Francisco, Calif, 1965)], and a subsequent compression suggested by Henning et al. J. Opt. Soc. Am A 17, 1147 (2000)] captures a range of hitherto unexplained interactions between a sinusoidal grating of low spatial frequency and a contrast-modulated grating 2 octaves higher in spatial frequency.