If you’re helpless without your glasses, try using your ears. For some tasks, hearing can augment poor eyesight, according to research reported by Wake Forest University Baptist Medical Center today at the annual meeting of the Society for Neuroscience in New Orleans.
“It has been long known that blind people often develop more acute hearing,” said Mark Wallace, Ph.D., senior researcher. “What we’ve shown is that hearing can also help people with mildly impaired eyesight and that it works immediately – it doesn’t take time to develop. This suggests that we could find ways to reduce disability in people with vision problems such as cataracts by teaching them to use both senses.”
For the study, participants sat in a dark room and were asked to point to the location of a randomly placed light. Sometimes, the light occurred at the same time as a sound. Participants with good vision could easily localize the light – and weren’t helped by the addition of sound. But when they wore goggles that simulated nearsightedness, the sound dramatically improved their performance.
"When they wore goggles, the participants’ ability to locate the light declined,” said Wallace. “But when sound was added, they were just as good as when they had normal vision.”
Wallace, an associate professor of neurobiology and anatomy, explained that because the visual system is so good, it normally doesn’t need the auditory system to locate objects in space. But, when the function of the visual system is degraded because of nearsightedness or bad lighting conditions, people are able to use their auditory system to help their visual system.
“If people keep their glasses off and use their ears to help them locate things, they might be surprised at how well they would do,” said Wallace. Wallace said the findings support an emerging idea in neuroscience – that if one sensory system isn’t performing well, the brain can use information from other senses.
“For a long time, neuroscientists have thought of the brain as having areas for vision, areas for hearing and areas for touch. Now, we’re starting to learn that the areas talk to one another and if one area is doing poorly, the others seem to have the ability to substitute or help.”
Next, Wallace and colleagues will use functional magnetic resonance imaging to determine which parts of the brain are activated during the study task in hopes of learning more about how the different senses work together.
Wake Forest University Baptist Medical Center is a health system comprised of North Carolina Baptist Hospital and Wake Forest University School of Medicine that operates 1,291 acute care, rehabilitation and long-term care beds.
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Media Contacts: Karen Richardson (krchrdsn@wfubmc.edu) or Shannon Koontz (shkoontz@wfubmc.edu) at 336-716-4587.