Thu, Apr 09, 2009 - Page 9 News List

The brain is an organ that just won’t be contained

There is evidence that the brain can be trained to compensate for damaged areas, which augurs well for medical and behavioral therapy

By Ian Sample  /  THE GUARDIAN

On 8 March 1969, an extraordinary experiment was reported in the pages of Nature, Europe’s leading science journal. A group of people took turns sitting in an old dentist’s chair and describing the room around them. They commented on the presence of a phone on the table, a nearby vase, facial expressions and how they wore their hair. It was remarkable because all were blind.

The scientific establishment took a dim view of the work and, for the most part, dismissed it as implausible. But today it stands as one of the first, and most striking, demonstrations of neuroplasticity, the brain’s ability to adapt. The blind people had learned to “see” through the sensation of touch.

Here’s what happened. The back of the chair had been fitted with hundreds of tiny stimulators that were hooked up to a video camera. As the camera panned the room, those in the chair felt tiny vibrations that seemed to dance across their skin as the image moved. With practice, the blind volunteers’ brains learned to turn these vibrations into a mental picture of the room. Some became so good at it that they ducked when a ball was tossed at the camera.

What was regarded as fringe science 40 years ago is currently at the cutting edge of neuroscience. With the right training, scientists now know the brain can reshape itself to work around dead and damaged areas, often with dramatic benefits. Therapies that exploit the brain’s power to adapt have helped people overcome damage caused by strokes, depression, anxiety and learning disabilities, and may one day replace drugs for some conditions.

Some studies suggest therapies that tap into the brain’s neuroplasticity are already making a big difference. Children with language difficulties have been shown to make significant progress using computer training tools that are the equivalent of cerebral cross-training. Work is under way to investigate whether it is possible to stave off a loss of brain plasticity in older age, which might help to address memory problems linked to Alzheimer’s disease. Some psychoanalysts are adopting techniques to help people overcome relationship troubles, obsessions, worries and bad habits.

The idea of brain plasticity has been discovered and forgotten many times over the centuries. The ancient Greeks accepted the idea, with Socrates believing that people could train their brains the way gymnasts train their bodies.

Around the time of Galileo, the idea fell out of favor as scientists began to see the world mechanistically, with each object, organ and even parts of an organ being attributed well-defined, unchanging roles. It was these ideas that led to the notion of our brains being “hardwired,” an idea that today is steadily being overturned.

Norman Doidge, a psychiatrist at the University of Toronto and author of The Brain That Changes Itself, says our belief that our brains are hardwired has held up medical progress.

“Our best and brightest neuroscientists thought our brains were structured like complex machines, with each part performing one function in one location, and that had implications. If you were born with a part that was defective, and say it gave you a learning disorder, it meant there was nothing you could do; you had to learn to live with it. If you sustained a brain injury or had a stroke and part of your brain broke down, there was nothing you could do. Brain exercises made no sense, and even more fundamentally, human nature was as fixed as the brain from which it emerged,” he says.

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