Our brains can continue to grow at any age. One of the startling revelations of the 21st century is the improvement in our knowledge of nerve cell development among older adults. Known as neurogenesis or brain plasticity, this new knowledge is showing us that the brain has the ability to CHANGE throughout life by forming new connections between brain cells, and to alter function. For a long time, it was assumed that as we become older, the connections in the brain became fixed, and then it was just a matter of time that we started “losing” brain cells. However this assumption is being aggressively challenged by recent studies showing that the brain never stops changing.
This evidence comes from a number of different observations. In a study of London taxi drivers who are learning some 25,000 streets, researchers found that compared with bus drivers (who had a fixed route), taxi drivers’ brains changed, with more brain cells growing in one part of their brain that is related to knowledge of maps. This study shows that the brain is an active neurological mechanism and not just a warehouse for cells. The brain is more than a reserve gas tank, switching from tank A to tank B, but has ‘plasticity’, a flexibility that can change the capacity and function of specific areas.
Plasticity can also be observed in the brains of people who speak more than one language. It appears that learning a second language is possible through functional changes in the brain: the left back part of the brain is larger in bilingual speakers than in the brains of those who just speak one language. Differences also occur in musicians’ brains compared to those of non-musicians. Brain volume was highest in professional musicians, intermediate in amateur musicians, and lowest in non-musicians in several brain areas. Finally, extensive learning of abstract information can also trigger some changes in the brain. By looking at the brains of German medical students three months before their medical exam and right after the exam, then comparing them to brains of students who were not studying for exam, students’ brains showed changes in regions known to be involved in memory retrieval and learning.
This growing evidence is popularizing the idea that the adult brain is more malleable than assumed and that it can regenerate throughout life. Decreased mental capacity is something that occurs through physical and functional changes in the brain. It can be avoided and even reversed through a variety of environmental enrichment activities, including physical and mental training exercises. The secret is to challenge the brain, to do novel and stimulating tasks that do not rely on established ways of doing things.
A number of new computer programs can help accomplish this. San Diego County is lucky to have a community college system for older adults that offer these programs for free. Working with Pat Mosteller, SDSU gerontology program is looking at how effective these programs are among older adults of different ethnic backgrounds. Other novel things you can do independently—start writing with your opposite hand, learn an exotic language, listen to bird songs and figure out what birds they are, learn to play an instrument, or learn mathematics.
Hopefully we will be able to show that we can teach old adults new tricks after all.
Mario Garrett PhD is a professor of gerontology at San Diego State University. He can be reached at mariusgarrett@yahoo.com © Mario Garrett 2010
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