December 22, 2008
Navigating Through Maze Is Possible For Blind Man
It has been discovered that a blind person could navigate through a maze of obstacles unaided using the power of sense alone.
A man left blind by a stroke was able to intuitively walk around chairs and boxes without bumping into them using hidden pathways in the brain.
Research was published in Current Biology by the Harvard Medical School.
The patient was left blind after damage to the visual (striate) cortex in both hemispheres of the brain following consecutive strokes.
The patient, known as TN, has normal eyes but his brain cannot process the information they send in, rendering him totally blind.
He was previously known to have "blindsight" which is the ability to detect things in the environment without being aware of seeing them.
For example, he responds to the facial expressions of others.
However, he walks like a blind person, using a stick to track obstacles and requires guidance by other when walking around buildings.
The scientist set up video recording around him that showed him completing the obstacle course set up, without the aid of his cane or another person.
Dr. Beatrice de Gelder of Tilber University, said that TN was "not aware of doing anything exceptional" and thought all he had done was walk straight ahead along a long corridor.
She said that it was an important message for those with brain damage in particular.
"You can experience a total loss of your cortical vision but still retain some capacity to move around inside and out without damage to yourself," she told the BBC.
"It shows us the importance of these evolutionary ancient visual paths. They contribute more than we think they do for us to function in the real world."
Sonai Rughani, an optometrist and senior advisor to the RNIB, a U.K. charity, said it was a striking observation, and further evidence that the brain is very flexible.
She also added that a relatively few number of people were left behind through brain injury, and most people with sight problems following a stroke could be helped by complex therapy regimes.
"These are very exciting findings but it will require further research," she added.
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