Re: Teenage Brain ~ use it or lose it

[Guest guest]

It used to be thought that interventions were most effective before the age of five, but now it seems that there is another window of opportunity during adolescence - use it or lose it.

http://www.walrusmagazine.ca/print/2006.11-science-the-teenage-brain/

And this is the crux: the frontal lobe, or more precisely the prefrontal cortex, is the home of the so-called “executive functions†: planning, organization, judgment, impulse control, and reasoning. The part that should be telling the sixteen-year-old not to dive off the thirty- foot cliff into unknown water. The seat of civilization. What Giedd has witnessed via mri is a constant push and pull in the grey matter. Certain forces cause a process known as arborization, during which grey matter gets bushier and grows new dendrites. Balancing that is a regressive pull, a competition for survival of sorts, in which some branches of the grey matter thrive while others are sacrificed. Both processes are continuous; as some new pathways grow, others are being pruned back. The quantity of grey matter peaks in girls around the age of eleven and in boys around thirteen, after which the amount of white matter increases. As grey matter decreases, there is also an increase in myelination, a process during which neurons, or nerve fibres, are insulated to enhance their performance. In the end, though, the amount of grey matter isn’t really the issue. “It’s much more related to quality than quantity,†explains Giedd. “This pruning process is normal and natural and healthy in terms of optimizing the brain for different environments. Our brains are built to be very adaptable during the teen years†— just the time when children start to figure out how to make it in the world. “The brain is incredibly plastic, which allows us to make it at the North Pole or the equator, to use a computer versus hunting with a stick. The teen brain is able to make changes depending on the demands of the environment.†(This might explain a thirteen- year-old’s ability to easily master new technology while parents struggle with the TV remote.) What determines the fate of a cell is whether it has made a meaningful connection with other cells. This is a real use-it-or-lose-it process. As some scientists have noted, if an adolescent forgoes reading in favour of lying around on the couch playing video games, those unused synapses will be pruned. Nobel Prize-winning scientist Gerald Edelman has called this “neural Darwinism†— the survival of the fittest synapses. So scientists know that different activities — playing sports, speaking a second language, drinking, smoking, and so on — influence how the adolescent’s brain will ultimately be wired, though they aren’t clear what the implications are: Is the pianist going to do better in life than the crossword- puzzle fiend? Will the jock have a leg up, brain-wise, on the geek? “Can you actually see changes in the brain of someone doing music? The answer to that is yes,†says Giedd. “But is that a good thing particularly? Is it just that our brains will become specialized in whatever we spend our time doing or is there a more general benefit?†See AOL's top rated recipes and easy ways to stay in shape for winter.