Explaining and classifying brightness-perception illusions by a new receptive-field approach

Abstract

Failure of isotropic difference-of-Gaussian (DOG) models of receptive field (RF) to explain brightness perception illusions like White effects, led many researchers to either discard low-level RF models in favour of orientation-selective nonlinear versions of DOG or totally abandon spatial-filtering-based approaches. However, even explaining low-level brightness-contrast illusions like, say, simultaneous brightness contrast with an isotropic DOG model requires judicious choice of parameters (scales, coefficients). Hence, a supportive role of high-level vision even in such simple cases cannot be ruled out. Such an interplay between low-level and high-level vision is predicted by a simple model of the extra-classical RF that modifies the classical DOG model with an additional wider Gaussian representing the extended disinhibitory surround (Ghosh et al, 2006 Biological Cybernetics 94 89-96). It is further concluded that such an approach classifies brightness-perception illusions including checkerboard, Todorovi & cacute; and Howe stimuli into three groups that represent either purely contrast-based (eg Mach band), or predominantly holistic (eg White effects), or intermediate (eg grating induction) perceptual phenomena.