Don't trust your eyes unless you've got earplugs in. Sounds can actuallychange what you "see," research reveals, and that news may impact everything from driving to philosophy.
Brandeis University psychologist Robert Sekuler, Ph.D., had long pondered the way our senses influence each other. "Taste is profoundly affected by smell," he notes. "And the eye can easily trick the ear, as ventriloquists know." But nobody had ever tested the effect of sound on sight. So Sekuler and colleagues designed an optical illusion on computer: Two disks approach each other, merge--overlapping perfectly for an instant--and move on. How does the eye interpret this dance--as two ships passing in the night, or two balls colliding and bouncing backward?
The answer It depends on the presence of sound. Sekuler found that "if there is a tone or click at the moment of collision, people see the disks bouncing off each other twice as often as when there is no sound at all." Are we actually seeing with our ears? No. We see the world with our brain, and at best that organ is merely a very good guesser, says Sekuler. "The retina takes a three-dimensional world and collapses it into signals. It sends those signals to the brain, which makes the best guess it can about what could have given rise to that information." Add a sound, and the brain instantly factors that into the mix.
