Cues to illumination do not cause Coren and Komoda's illusion of lightness in an ambiguous tube.
The inside of a picture of a uniformly gray tube drawn with black circles appears lighter than the outside. Coren and Komoda, who first described this illusion, argued that observers take illumination into account to infer that the inside is lighter. That is, the inside of the tube should receive less illumination than the outside but reflects the same amount of light into the eyes. Observers, therefore, infer that it must be lighter. The inside of a gray tube drawn with white circles should appear lighter as well according to this account, but the experiments reported here show that the outside appears lighter in such a tube. We believe that depth perception is involved in this illusion but that lightness constancy is not.
Schulman
P H
PH
Department of Psychology, SUNY Institute of Technology, Utica 13504, USA. fphs@sunyit.edu
Van Etten
S
S
D015350:Contrast Sensitivity; D003867:Depth Perception; D006801:Humans; D008029:Lighting; D009903:Optical Illusions; D009949:Orientation; D010364:Pattern Recognition, Visual; D011601:Psychophysics