Kanizsa triangle

Paradoxically, Kanizsa’s fame depends on something that does not exist. Truncated disks and outline corners are so arranged as to induce the presence of an illusory surface that appears different from its background despite the homogeneity of stimulation inside and outside its contour. Kanizsa12,13 ultimately called such figures “anomalous”, to emphasize that they emerge in the absence of physical inhomogeneities normally associated with borders. The Kanizsa triangle (both the one with black inducers on white background and the one with one with white inducers on black background) appears stratified in the forefront, with a sharp margin that includes a surface whose color is more insistent than in the background.