Friday, August 10, 2012

US Scientists Aim to Deliver Visual Images to People with Vision Disabilities

Humans possess the unique ability to form mental images of things that exist only in their minds, and U.S. scientists now believe there may be a way to harness this ability someday to give sight to people who are blind.

Neuroscientists at Baylor College of Medicine and the University of Texas Medical School at Houston have recently advanced their understanding of how the brain conjures up images, and hoped to someday bypass the eyes to directly deliver visual images into blind people’s brains, according to the latest online edition of the Texas Medical Center News on Monday.

In studying three individuals and creating an illusion of the flash of light to stimulate the brain, the scientists discovered two regions of all the three people’s brains required stimulation before the individuals could generate mental images in their mind.

The occipital lobe, a part of the brain at the back of the head, is responsible for vision and mental images, but the scientists discovered the brain’s temporoparietal junction must be active and work in conjunction with the occipital lobe for individuals to “see” an image in their mind, at least in the three people studied.

“This new study is a step toward our goal of better understanding visual perception, which will help us make a useful visual prosthetic,” said Daniel Yoshor, the study’s senior author.

A visual prosthetic, Yoshor said, could work like this: People who is blind might wear a prosthetic consisting of eyeglasses containing a webcam. The tiny camera would film the scene before blind person’s eyes, then relay information to a computer chip implanted in the person’s brain, which would stimulate the brain to generate mental images.

“If successful, we would in essence bypass eyes that no longer work and stimulate the brain to generate mental images,” said Michael Beauchamp, the study’s lead author and an associate professor of neurobiology and anatomy at the UT Medical School.

However, Yoshor, also chief of neurosurgery at St. Luke’s Episcopal Hospital, noted that a key obstacle to progress right now “is our limited understanding of how brain activity leads to visual perception.”