People's Senses Are Ever-Adjustable

Those soldiers and Marines who battled their way across the deserts of Iraq while blinded by fierce sand storms succeeded despite the fact that they had temporarily lost the use of the most critical of all sensory systems — vision.

Our eyes are the "teacher" that helps us calibrate all our senses, enabling us to sort through the flood of confusing sensory messages and navigate across the battlefield, or maneuver through the maze of chairs and desks in our offices.

That may be stating the obvious in that we all know it would be tough to be blind, but ongoing research at the University of Rochester Medical Center shows that our eyes are far more than just the tools we use to see the world around us. They are the key to our remarkable ability to adapt to the loss of some of our sensory abilities, according to neuroscientist Gary Paige, and his research shows that we adapt much more quickly and efficiently than had been thought.

All in the Eyes

It is our eyes, he says, that taught our brains how to figure out which direction a sound is coming from, and which voice belongs to which person calling out in a crowded room.

Paige worries about a lot of things, like how pilots can take off from an aircraft carrier into a dark sky, and fly essentially blind across hundreds of miles to drop their bombs on dark targets. They do it with instruments, of course, but he notes that the fact that they are able to do it at all is nothing short of remarkable.

"You have an airplane that is capable of incredible acceleration and maneuvers, and vision that is somewhat worthless because there's nothing out there to see," he says. "You have no bearings whatsoever through vision."

Rapid acceleration distorts the sense of gravity, and a pilot feels like the aircraft is climbing sharply, even if it is going straight ahead, leading to possible errors that could be deadly.

But it is the eyes that allow the pilot to focus on instruments instead of his errant senses, and after awhile the pilot doesn't even have to think about it. It just comes naturally.

Disorienting Goggle Test

The same thing happens in the more mundane events in our lives. Illness damages our sense of balance, for example, but we adapt quickly to reduce that hardship, and even in that seemingly unrelated situation the eyes play a crucial role. That ability didn't come with the body, Paige says. We learned it.

To research that issue, 10 people at the university spent days wearing goggles that were designed to distort their vision. Paige wanted to see how their brains would adapt to a world that suddenly looked out of kilter.

Graduate student Owen Brimijoin says it was sort of like looking at life through the peephole in the front door of his apartment. The wide-angle view left him disoriented and a bit nauseous. When he reached out for an object, it wasn't where he thought it was.

"I was worthless at first," says Brimijoin, who heard sounds that seemed to be coming from the wrong place, and couldn't tell who was speaking until he saw a mouth moving. But within a couple of days, he had adapted completely, although he still had to endure the curious stares that his goggles attracted from people on the street.

He adapted because even his distorted vision allowed him to "calibrate" his sensory organs, Paige says.

Calibrating Our Senses

"You are born with a variety of sensory inputs," he says, but they all have to talk the same language. Those organs most likely were not "in sync" at birth.

"Why would they be calibrated when you were born?" he asks. "You've never seen before, and you've never heard before."

But even as infants, we see mom speaking, and see that she is above and slightly to the right, thus using our vision to calibrate our hearing. Eventually, we don't need our eyes to determine the location of the source of the sound. Our ears have learned how to do it, even in the dark.

Persons who are born blind probably achieve the same thing at a much slower pace by trial and error, Paige suggests.

Paige's research, sponsored by the National Institutes of Health and the international Human Frontiers Science Program, took it a step further. He wanted to see if the eyes continue their role as teacher, even as we grow older.

So his students spent days wandering around with weird glasses and distorted vision to see if they could adapt to a new world order. It turns out it was a piece of cake.

Within a couple of days, Brimijoin says, sounds no longer seemed to be coming from the wrong place. He didn't have to think about it anymore. His sensors had all been re-calibrated, allowing him to function about as well as he had before.

"Pretty soon you don't even think about it anymore," Paige says. "It becomes part of your new world order. That demonstrates that the eyes are the teacher."

Lee Dye’s column appears weekly on A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.