Sight is an Illusion

I apologize in advance for the lengthy (and highly mumbo-jumboed) blog today, but I ran into this article during my research, and had to share it. I think it's pretty cool that we see in 2D, and perceive in 3D. What do we do during 3D movies? Is our natural ability being enhanced or just messed with? The idea that a fish can escape by looking like it doesn't exist goes way beyond camouflaged and into the just plain freaky.

SEEING WITH THE BRAIN

Illusions in art are essentially phenomena of perception. As neuropsychologist Richard Gregory tells us, the eye and brain combine "to give detailed knowledge of objects beyond the range of probing touch.... Seeing is probably the most sophisticated of all the brain's activities." The brain-that is, the visual cortex-is constantly making perceptual hypotheses on the basis of electrical impulses transmitted to it from the retina, and this process is not under intellectual control.

V S. Ramachandran put it this way: "Our visual experience of the world is based on two-dimensional images: flat patterns of varying light-intensity and color falling on a single plane of cells in the retina.Yet we come to perceive solidity and depth.We can do this because a number of cues about depth are available in the retinal image: shading, perspective, occlusion of one object by another, and stereoscopic disparity. In some mysterious way the brain is able to exploit these cues to recover the three-dimensional shape of objects."

The ability to exploit shading is probably the most primitive of all.To the vertebrate brain (including our own), since there is only one sun in our solar system, the light source is usually from above, and that light source is single. The extreme antiquity of this perceptive cue can be seen in the widespread evolutionary exploitation of countershading in nature: that is why preyed-upon animals such as fish and deer are dark on top and light below-to avoid detection.

*To give credit where it's due, the article is by Michael D. Coe, and is called "Art and Illustration Among the Classic Maya" from the Record of the Art Museum, Princeton University (Vol. 64, 2005, p. 52-62)