THE CRAIK-O’BRIEN-CORNSWEET ILLUSION IN HONEYBEES

M. P. Davey, M. V. Srinivasan and T. Maddess

Humans perceive a low contrast Craik-O’Brien-Cornsweet (COC) grating as being similar to, or even indiscriminable from, a squarewave grating, despite the fact that the spatial intensity profiles of the two patterns are very different (Cornsweet, 1970). This similarity has been attributed to processing at early stages of the visual pathway which selectively transmits edge information, followed by cortical mechanisms which "fill in" the appropriate intensities between the edges (Grossberg and Todorovic, 1988). Here we find that bees behave as though they experience a similar illusion, suggesting that certain principles of visual processing may be shared by insects and humans.