From Visual Plasticity to the Bionic Eye
While visual plasticity is strongest in early infancy, new studies show that plasticity is maintained well into adult life.This possibility is compellingly demonstrated by one patient, SK, who gained vision for the first time in adult life andsignificantly improved his ability to see the world around him. The persistence of visual plasticity in adults is promisingnews for the developing field of visual prosthesis.In recent years, there has been an explosion of research on prosthetic devices for the brain. While memory-enhancingbrain chips are still science fiction, cochlear implants, which stimulate the inner ear with tiny electrodes, now allowpeople who were once deaf to hear with increasing accuracy. Although there is not yet any visual equivalent to thecochlear implant, in recent years vision researchers have started to experiment with similar prosthetic techniques totreat blindness.The goal of visual prosthesis is to allow functional restoration of vision and to improve quality of life for blindpatients. In order to achieve these goals, the prosthetic devices must tap into the brain’s plasticity. Plasticity is howthe brain adapts to new environmental stimuli. It enables all forms of learning, including memorizing facts, playingthe piano, and learning to see. Specifically, plasticity is how neural networks in the brain reorganize in response tonew experiences. Understanding plasticity furthers insight into the brain mechanisms active in visual prostheses, andmay help scientists develop new approaches for future devices.