delanceyplace.com 01/26/06 - the brain rewired

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In today's excerpt  - parts of the brain that get most heavily used literally expand and rewire on demand:

"... Paul Broca's (1857) ... and subsequent discoveries gave rise to the dogma of the hard-wired adult brain. ... It held that if the brain sustained injury ... the function of the injured region would be lost forever. ... But that dogma has been under assault in recent years.

"... [new theories demonstrate] the adult brain is 'plastic', able to forge new connections among its neurons and thus rewire itself. Sensory input can change the brain, and the brain remodels itself in response to behavioral demands. Regions that get the most use literally expand. In terms of which neural circuits endure and enlarge, you can call it survival of the busiest.

"... [in one example] there was a huge difference between violin players and nonmusicians in how much of the cortex was devoted to 'feeling' the fingers of the left hand. ... [In another example] John Gabrieli of Stanford University ... found that ... in dyslexics whose language comprehension had been improved, the brain's left prefrontal region showed more activity after training."