For a long time, scientists believed two things about the brain.
The first was the idea that you're born with a set number of neurons -- "brain cells." Then, you lose them all your life.
The second idea was that there are "hardwired" parts of the brain. Various experiments showed that one region was involved in visual processing, another in movement (controlling the arms or legs, for instance). If you went blind, the part of the brain set up to handle information from the eye just sat there, dark and quiet.
Both of these ideas, we now know, were wrong. And that's very good news.
It turns out that we manufacture brain cells all the time. They nestle into the existing network of memories and skills. But they do best -- grow rich connections, perform at peak efficiency -- when challenged by a certain amount of novelty. What we're wired to do is learn.
The second idea is what is now known as plasticity. Recent advances of brain imagery have revealed that although the human brain does have certain patterns of typical use, no two brains are quite alike. The fundamental organizational structure of the brain is surprisingly malleable.
For instance, people who lost their sight as young children still have a lot of activity in the visual center. How can that be?
Answer: since no information was coming in involving sight, the brain (apparently incapable of idleness) started processing sounds. You've heard the idea that when you lose one sense, the others sharpen. Well, blind people don't actually hear things sighted people don't. They're just much better at paying attention to what might be called "peripheral" sounds.
In much the same way, people who lose their hearing suddenly find that they're far better at tracking peripheral sight. And the part of the brain that used to process sound, now "fires" when tracking visual cues.
It turns out that almost any part of the brain can be repurposed in this fashion.
One method for doing that is sensory practice. Stroke victims, for instance, might lose control of an arm. Conventional therapy focused on using the other arm. Brain research suggests the opposite: bind the good arm, and work, work, work, on getting the disabled arm to function again. And slowly, it does -- literally grabbing hold of new brain real estate to build new connections.
In much the same way, dyslexia, for at least some people, seems to be related to the auditory cortex. Some people just don't hear the sounds marking the difference between "d" and "p." But by using a program called Fast ForWord -- which slowed down and stretched out the sounds, then gradually speeded them up -- "after twenty to forty hours of training, all the children (in a study) ... had advanced two years in language comprehension." And that new comprehension could be tracked through brain imagery. The brain dedicated a little space to the problem, and that solved it. (Incidentally, this same program has been found to be surprisingly useful in restoring the hearing and mental acuity of old people. I have filed this tip away for the future.)
But a far more exciting discovery is that the mind can change the structure of the brain. We know that "practicing" -- whether a golf swing or a musical instrument -- has a measurable effect on the brain. That's more sensory input. But studies show that just thinking about practicing has pretty much the same effect. The same neurons fire; the same structural changes take place. It gets a little spooky.
This shows great promise in another area: the treatment of psychiatric disorders, such as Obsessive Compulsive Disorder or depression. Experiments show that just "noticing" what's going on -- "there's that sense of urgency again, there's that wacky brain misfire that says I left the stove on!" is enough to interrupt its grip.
The repeated exercise of nothing more than attention, noticing, also changes the brain, suppressing the dysfunctional parts, and growing new, more vibrant patterns elsewhere.
So what's the bottom line? Modern brain research (such as that captured in the excellent "Train Your Mind Change Your Brain" by Sharon Begley (foreword by the Dalai Lama) demonstrates that we are limited only by our thinking.
We can be just who we want to be.
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