Visual perception and cuttlefish camouflage.

Visual perception is inherently statistical: brains exploit repeating features of natural scenes to disambiguate images that could, in principle, have many causes. A clear case for the relevance of statistical inference in vision is animal camouflage. Although visual scenes are each composed of unique arrangements of pixels, they are usually perceived mainly as groupings of statistically defined patches (sandy/leafy/smooth etc…); this fact is exploited by camouflaging animals. The unique ability of certain cephalopods to camouflage actively within many different surroundings provides a rare and direct behavioral readout for texture perception. In addition, because cephalopods and chordates each arose after a phylogenetic split that occurred some 600M years ago, the apparent convergence of texture perception across these groups suggests common principles. Studying cephalopod camouflage may thus help us resolve general problems of visual perception.