Ph. Schulman et S. Vanetten, CUES TO ILLUMINATION DO NOT CAUSE COREN AND KOMODAS ILLUSION OF LIGHTNESS IN AN AMBIGUOUS TUBE, Perceptual and motor skills, 83(3), 1996, pp. 959-962
The inside of a picture of a uniformly gray tube drawn with black circ
les appears lighter than the outside. Coren and Komoda, who first desc
ribed this illusion, argued that observers take illumination into acco
unt to infer that the inside is lighter. That is, the inside of the tu
be should receive less illumination than the outside but reflects the
same amount of light into the eyes. Observers, therefore, infer that i
t must be lighter. The inside of a gray tube drawn with white circles
should appear lighter as well according to this account, but the exper
iments reported here show that the outside appears lighter in such a t
ube. We believe that depth perception is involved in this illusion but
that lightness constancy is not.