why we see what we do

There’s a wonderful new book called “why we see what we do” by Dale Purves, a neurobiologist at Duke. He’s found a way to quantify the strength of various optical illusions and has a theory that optical illusions reflect our mind’s attempts to get the real information from ambiguous optical information. For example, the reason why a gray square appears brighter when surrounded by black is because we perceive the dark area as a shadow and “know” that the gray square is actually a lighter square in dim light. His evidence for this is extremely good.

His web site has interactive optical illusions that beautifully illustrate the same points. It’s quite the eye opener on visual perception, particularly on how much is going on behind the scenes. It’s also interesting to think of his book in relation to those old bauhaus color theory books by Albers and Itten (other favorites of mine).

sonke