Some people who have lost their sight retain a peculiar relic of vision: They can "guess" the movement, color, and shape of objects around them and get the answers right most of the time. Neuroscientist Tony Ro at Rice University in Houston has now induced this spooky sense in people with sight and suggests that it may be an important part of how we perceive the world.
Short-circuiting the visual cortex with an electromagnetic zap, Ro induced momentary blindness in 10 test subjects with normal vision. During that split second, a computer flashed a picture of colored disks or of horizontal or vertical bars. Although the participants were not aware that they had seen anything, they could describe the color or orientation of the images correctly 75 to 80 percent of the time, well above the results of chance.
This phenomenon—sensing visual information without actually "seeing" it—is called blindsight. Ro ...
