Phantoms in the Brain next explains the visual cortex. We learn how we see by studying people with scotomas — blinds spots. Although our brain does have something like a one-to-one pixel of the world in our brain, it does not end there. Different areas of our brain specialize in different parts of the visual process: line-detection, texturing, motion. Psychologists have not fully enumerated all the areas, nor — for the areas they have enumerated — do they understand their exact function.

One thing is clear though: the areas are strongly interconnected, process information at different rates of speed, and do a lot of guessing. Some people have huge holes in their vision, yet when information is missing, the brain takes a best guess and what should be there and fills in the gaps. Your brain will connect broken lines, fill in corners, match colors. All of this happens in real time and uses the surrounding environment to deduce the likely outcome (question: how much of this is learned vs. innate?). It will even make up fake hieroglyphics (that you cannot read) inside your blind spot if you surround it with numbers. Motion takes longer to learn than does color or texture too. So if you have a blinking line, first your mind will connect the lines, then they will start blinking.

Yale has an interesting demonstration on some of this. I encourage you do have fun with your blind-spot.

Or if you have photoshop, you can download this file that I used to map the size of my blindspot and perform some of the same experiments.

This entry was posted on 2006-9-20 at 3:33 and is filed under Psychology. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.