Perceived Color and its Dependence on Focal, Surrounding, and Preceding Stimulus Variables*

Alternative formal definitions of perceived color are examined. Both alternative formulations treat the responses evoked by stimulation of a focal test area, but in one case the influence of surrounding stimulation on the primary test area is taken into consideration, whereas this influence is ignored in the other formulation. The consequences of these alternative formulations for predictions of equivalent stimuli and for predictions of color appearance under different circumstances are discussed.Sensory scaling experiments are reported which yield direct quantitative estimates of the hue, saturation, and brightness attributes of perceived color, and of the dependence of these attributes on variations in focal, surrounding, and preceding stimulation. The relation of some of these dependencies to opponent neural induction mechanisms postulated by the opponent-colors theory is discussed.