Incognito: The Secret Lives of the Brain

by David Eagleman

In the 1960s, the neuroscientist Paul Bach-y-Rita at the University of Wisconsin began chewing on the problem of how to give vision to the blind.25 His father had recently had a miraculous recovery from a stroke, and Paul found himself enchanted by the potential for dynamically reconfiguring the brain. A question grew in his mind: could the brain substitute one sense for another? Bach-y-Rita decided to try presenting a tactile “display” to blind people.26 Here’s the idea: attach a video camera to someone’s forehead and convert the incoming video information into an array of tiny vibrators attached to their back. Imagine putting this device on and walking around a room blindfolded. At first you’d feel a bizarre pattern of vibrations on the small of your back. Although the vibrations would change in strict relation to your own movements, it would be quite difficult to figure out what was going on. As you hit your shin against the coffee table, you’d think, “This really is nothing like vision.” Or isn’t it? When blind subjects strap on these visual-tactile substitution glasses and walk around for a week, they become quite good at