It turns out that the old positive mental attitude saw, "if you think you can or you think you can't, you're right," may well have science-based underpinnings. The science — neuroplasticity, or brain plasticity — indicates that we may be able to change not only our attitude, but other physical aspects of our brain as well.

It has long been understood that there is a high degree of brain plasticity in young people. (To see an astonishing video showing a remarkable example of child brain plasticity after surgery removing half the brain, go to www.youtube.com/watch?v=TSu9HGnlMV0. This video also contains an interesting conversation with surgeon Benjamin Carson, who performed the surgery.) What is new is that there appears to be significant plasticity in adult and even older adult brains.

The idea that brains can change is very new in the history of brain study. "For 400 years (the idea that the human brain can change itself) would have been inconceivable because mainstream medicine and science believed that brain anatomy was fixed," said Dr. Norman Doidge, "The Brain that Changes Itself." Doidge continues, "The common wisdom was that after childhood the brain changed only when it began the long process of decline, nor could the brain alter its structure and find a new way to function if part of it was damaged." Essentially, the new idea of neuroplasticity challenges this long-held, near-doctrinal belief that our brains are hard-wired.

I don't think it is just that I want to believe this. It seems deeply unjust for humans to labor under a misconception that their horizons, both in terms of physical and mental health, are bound by the supposed fixed capability and capacity of our brains. This scientific dogma has stunted our intellectual growth and limited our imagination for centuries.

"Brain plasticity refers to the brain's lifelong capacity for physical and functional change; it is this capacity that enables experience to induce learning throughout life," says Dr. Michael M. Merzenich. According to Merzenich and his colleagues, it was determined in a human study that significant improvements in memory enhancement resulted from a highly targeted memory training program. "This study demonstrates that intensive, plasticity-engaging training can result in an enhancement of cognitive function in mature adults" (Proceedings of the National Academy of Sciences, June 27, 2006).