Blind man walking: With no visual awareness, man navigates obstacle course flawlessly
Blind man walking: With no visual awareness, man navigates obstacle course flawlessly (12/25/2008)
Researchers have demonstrated for the first time that people can successfully navigate an obstacle course even after brain damage has left them with no awareness of the ability to see and no activity in the visual cortex, a region of the brain’s cortex that is primarily responsible for processing visual inputs. The findings published in the December 23rd issue of Current Biology, a Cell Press publication, reveal the importance of alternative routes in the brain, which are active in both those who have suffered severe brain damage to the visual cortex and in all of our everyday lives, according to the researchers.Earlier studies had shown a similar ability in monkeys with comparable brain lesions. The new study was possible only because of the participation of an unusual patient known as TN, who was left blind after selective damage to the visual cortex in both hemispheres of his brain following consecutive strokes.
“This is absolutely the first study of this ability in humans,” said Beatrice de Gelder of Tilburg University, The Netherlands and of the Martinos Center for Biomedical Imaging and Harvard Medical School. “We see what humans can do, even with no awareness of seeing or any intentional avoidance of obstacles. It shows us the importance of these evolutionarily ancient visual paths. They contribute more than we think they do for us to function in the real world.”
