Turns out, neural emphasis on movement is more important than “seeing” the image through the eyes.
If we study the evolution of homo sapiens, we’ll see that our visual systems were evolved to maximize the brain’s visual cortex to aid in targeting our prey. When a person goes blind, this portion of the blind remains unharmed but since there is no information received from the eyes, this part becomes useless.
But now, a team of researchers has published a paper in The Journal of Clinical Investigation which focuses on neural movement as the key to restoring sight in blind people. The researchers bypassed the eyes and instead produced perceivable images by directly activating the brain’s visual cortex with a device. A blind test participant took part in the research and was able to recognize letters and silhouettes of shapes.
The experimental device includes a forward-facing “artificial retina” which is put on a pair of glasses. The device detects light from the visual field in front of the glasses and converts it into electrical signals. These signals are then sent to a three-dimensional matrix of 96 micro-electrodes that is implanted in the user’s brain which penetrates it to stimulate and monitor the electrical activity of the neurons in the visual cortex. Light patterns are transmitted to the artificial retina, allowing the individual to perceive them.
A team from Spain’s Miguel Hernandez University tested the device on a 57-year-old woman who had been blind for about 16 years to get more accurate results as the previous studies made use of animals that were not blind so it hindered the accuracy of the study.
The woman was able to recognize letters and the outlines of specific shapes after she was trained and learned to understand the visuals produced by the device. Another significant find was that the implant did not affect the functioning of the cerebral cortex nor did it target nearby neurons. The implant also required less electrical current which made it safer to use.
