7.01.2008

Want a Migraine?

Here, look at this visual illusion (looks like a devastating scintillating scotoma)

I've never quite seen one like this before. There is no motion, but you perceive motion anyway.

The eye sends information to the brain through different types of neurons. Some of these neurons transmit information faster than others, and some of these neurons respond more quickly to high-contrast parts of an image than to low-contrast parts of the image. Because of these differences, the response of the eye to one part of the illusory pattern reaches the brain at a slightly different time than the response of the eye to another part of the illusory pattern. The difference in the arrival time is exactly the same type of event that would occur with “real” motion, and so motion detectors in the brain signal that motion has occurred.

No comments: