Correction Appended

Cheryl Schiltz vividly recalls the morning she became a wobbler. Seven years ago, recovering from an infection after surgery with the aid of a common antibiotic, she climbed out of bed feeling pretty good.

''Then I literally fell to the floor,'' she said recently. ''The whole world started wobbling. When I turned my head, the room tilted. My vision blurred. Even the air felt heavy.''

The antibiotic, Ms. Schiltz learned, had damaged her vestibular system, the part of the brain that provides visual and gravitational stability. She was forced to quit her job and stay home, clinging to the walls to keep from toppling over.

But three years ago, Ms. Schiltz volunteered for an experimental treatment -- a fat strip of tape, placed on her tongue, with an array of 144 microelectrodes about the size of a postage stamp. The strip was wired to a kind of carpenter's level, which was mounted on a hard hat that she placed on her head. The level determined her spatial coordinates and sent the information as tiny pulses to her tongue.

The apparatus, called a BrainPort, worked beautifully. By ''buzzing'' her tongue once a day for 20 minutes, keeping the pulses centered, she regained normal vestibular function and was able to balance.

Ms. Schiltz and other patients like her are the beneficiaries of an astonishing new technology that allows one set of sensory information to substitute for another in the brain.

Using novel electronic aids, vision can be represented on the skin, tongue or through the ears. If the sense of touch is gone from one part of the body, it can be routed to an area where touch sensations are intact. Pilots confused by foggy conditions, in which the horizon disappears, can right their aircraft by monitoring sensations on the tongue or trunk. Surgeons can feel on their tongues the tip of a probe inside a patient's body, enabling precise movements.

Sensory substitution is not new. Touch substitutes for vision when people read Braille. By tapping a cane, a blind person perceives a step, a curb or a puddle of water but is not aware of any sensation in the hand; feeling is experienced at the tip of the cane.




Meanwhile, a handful of clinicians around the world who are using the BrainPort on an experimental basis are effusive about its promise.

''I have never seen any other device do what this one does,'' said Dr. F. Owen Black, an expert on vestibular disorders at the Legacy Clinical Research and Technology Center in Portland, Ore. ''Our patients are begging us to continue using the device.''

Dr. Maurice Ptito, a neuroscientist at University of Montreal School of Optometry, is conducting brain imaging experiments to explore how BrainPort works.

Dr. Eliana Sampaio, a neuroscientist at the National Conservatory of Arts and M?ers in Paris, is using the BrainPort to study brain plasticity. Sensory substitution is based on the idea that all sensory information entering the brain consists of patterns carried by nerve fibers.

In vision, images of the world pass through the retina and are converted into impulses that travel up the optic nerve into the brain. In hearing, sounds pass through the ear and are converted into patterns carried by the auditory nerve into the brain. In touch, nerve endings on skin translate touch sensations into patterns carried into the brain.

These patterns travel to special sensory regions where they are interpreted, with the help of memory, into seeing, hearing and touch. Patterns are also seamlessly combined so that one can see, hear and feel things simultaneously.

''We see with the brain, not with the eyes,'' Dr. Bach-y-Rita said. ''You can lose your retina but you do not lose the ability to see as long as your brain is intact.''

Most important, the brain does not seem to care if patterns come from the eye, ear or skin. Given the proper context, it will interpret and understand them. ''For me, it happened automatically, within a few minutes,'' said Erik Weihenmayer, who has been blind since he was 13.