“Often people compare the workings of the brain to that of a computer. In the late 1980s the brain of a human being was thought to be akin to a biological computer, as one scientist puts it, “secretes thoughts the way kidneys secrete urine.” Neuroscientists know understand that there is more to it than that, and our brains are much more complex than any computer. It is much more organized, changes on its own, repairs itself, and often makes decisions we have not programmed it to make.
Over the last decade technology has shown that brain plasticity is much more complex than simply connecting neurons to other neurons. Compelling evidence has come from studies of the blind, conducted by Alvaro Pascual-Leone, now a professor of neurology at Harvard University and Boston’s Beth Israel Hospital.
Early in the 1990s Pascual-Leone and his colleagues at the National Institutes of Health found that when blind adults were learning Braille regions of the brain, the somatosensory (touch-sensitive) cortex, enlarged as it reacted to data input provided by the reading finger. In addition, the visual cortex near the back of the brain reacted as well, even though they were not able to see.
The scientists wondered if it was possible that new nerve connections were stretching themselves to reach across the brain to take up space once occupied by neurons in the vision area? In order to test that hypothesis, Pascual-Leone blindfolding sighted individuals for five days. They found from functional magnetic resonance imaging (fMRI) scans that in as short a time as two days there were bursts of activity in the visual cortex area when the people performed tasked that required the use of their fingers, or when they were listening to words or music.
This was too short a time for nerve connections to generate and grown from the touch and hearing areas of the brain and reach across to the areas that process sight. Even more fascinating was that after the blindfolds were removed it only took a few hours for the visual cortex to return to normal and only respond to input from the eyes.
What would cause the brain to “see” input from the fingers and ears? Pascual-Leone believes the connections from the other senses to the visual cortex are there in blind people, but remain unused as long as the eyes are doing their job. When the eyes are not able to perform as usual the “back up” plan kicks in and takes over.
“It’s provocative, but we’re arguing that the brain may not be organized into sensory modalities at all,” he says. It is possible that the area of the brain scientists have referred to as the visual cortex for so many decades is in fact not exclusive to the eyes. Perhaps this area of the brain is devoted to spatial relationships, and will react to whatever stimulation it received in order to perform it’s tasks.
This is quite an interesting turn of events, and definitely opens up another can of worms to explore. Our brains never cease to amaze us.
About the author:
Ron White is a two-time U.S.A. Memory Champion and memory training expert. As a memory keynote speaker he travels the world to speak before large groups or small company seminars, demonstrating his memory skills and teaching others how to improve their memory, and how important a good memory is in all phases of your life. His CDs and memory products are also available online at BrainAthlete.com.
Sources:
Brain Structure, by Craig Stellpflug NDC; http://www.healingpathwaysmedical.com/docs/Brain_Structure.pdf
