“…Although this explanation is now believed to be deficient on the grounds that it predicts Mach bands to be strongest at a step edge where in fact none are observed (Fiorentini, 1972;Ross, Holt & Johnstone, 1981;Ratliff, 1984), it nevertheless anticipated themes central to our current understanding of vision. More recently, brightness illusions have been studied in the context of linear systems analysis (Campbell, Howell & Robson, 1971;Campbell, Howell & Johnstone, 1978;Sullivan & Georgeson, 1977;Dooley & Greenfield, 1977) have been predicted in a number of computational models of both spatial vision (Watt & Morgan, 1985;Morrone & Burr, 1988) and reflectance recovery (Horn, 1974;Land, 1986;Hurlbert & Poggio, 1988;Blake, 1985) and have been the principal subject of models explicitly concerned with brightness coding (Arend, Buehler & Lockhead, 1971;Arend & Goldstein, 1987;Hamada, 1984;Cohen & Grossberg, 1984;Grossberg & Todorovic, 1988;.…”