Color-constancy illusion

Michelle, Lauren, and I stumbled on a strong illusion last night. It's similar to the checkerboard illusion but involves color rather than just shades of gray.

The "blue" tiles on top of the left cube and the "yellow" tiles on top of the right cube are actually the same shade of gray.

Articles that talk about this illusion: American Scientist: Why We See What We Do and Discover Magazine: Sensory Reflexes. (The authors of the American Scientist article wrote a book with the same name.)

Berkeley's dilemma (as described by the American Scientist article) reminds me of Quine's Gavagai problem in the acquisition of language. Berkeley's dilemma is that retinal images are inherently ambiguous -- for example, there's no difference in the retinal image created by a large object at medium distance and a small object at a large distance. In the Gavagai problem, an island native points to a rabbit and says "gavagai". Do you interpret "gavagai" as "rabbit", "there goes a rabbit", "white", "animal", "hopping", "it's a nice day", "cute", "lunch", or something else?

Both Berkeley's dilemma and the Gavagai problem are problems of infinite ambiguity. Humans have clever heuristics for dealing with both problems. Examples include color constancy and overestimation of acute angles in visual perception, and the whole-object, taxonomic, and mutual-exclusivity assumptions children use to interpret new nouns.

4 Responses to “Color-constancy illusion”

  1. Grey Hodge Says:

    Anyone who has worked in televsion or movies, or even still photography, knows about “Berkeley’s dilemma”, although not usually by any particular name. It’s why forced perspective in TV/Film/Photos works. When given a monocular point of view, the brain depends on context and pattern recognition to determine scale and scope. It’s also the assumed evolutionary impetus for binocular vision.

    In the Gavagai problem, the pointing action DOES tend to rule out “it’s a nice day” though. :)

  2. paul birk Says:

    hi, im not sure if i will get a response to this message but i would be gratefull if you would be able to advise me with a final year project that i am currently working on. i am a graphic design student and have chosen to do my final year project on colour in design. the project research shows the importance of colour and from this research i have to produce a final peice of work the format of which is open! i have been thinking of holding a small exhibition, however i am torn between ideas as to what i should exhibit that will truly provide a focus from my research. please could you advise me as to what i can do?

  3. edit me Says:


    The “blue” tiles on top of the left cube and the “yellow” tiles on top of the right cube are actually the same shade of gray. More about the Color-constancy illusion……

  4. Apostle to the Apostles Says:

    Fun with lightness perception

    Everybody knows the optical illusions by M.C. Escher but there are other interesting things around. Jesse Ruderman has an entry regarding color constancy illusions and a link to the known checkerboard illusion. If you want to get a not…