Innovative
Physical Therapy Helps Disabled to Walk
Courtesy The
Black Collegian Magazine Online
Exactly how plastic is the adult brain? We don't know, you don't know, and scientists don't either -- but it's probably much more flexible than anybody suspected one or two decades ago. We've seen evidence in the movement of stroke victims, and the language abilities of Japanese speakers and dyslexic children.
Michael
Merzenich, who helped develop the dyslexia program, is a neuroscientist
at the University of California at San Francisco. Last winter, Merzenich
told a meeting of the American Association for the Advancement of Science
that brains respond to experience by changing their wiring.
Merzenich started making that argument in the 1980s, to highly skeptical colleagues. Today, large-scale rewiring -- what he calls "massive cortical reorganization" -- is better accepted in the brain biz.
Merzenich's argument has been buttressed by new brain-imaging machines, which show that the brains of children with language processing deficits are "physically different" in the location and size of structures necessary for language.
A
clear picture
When language-impaired children are taught to hear the individual sounds
of language, they learn to distinguish letters long after the "critical
period" for language development, Merzenich says, and these changes appear
in brain images as well as their improved language abilities.
Behavior can be quite a teacher of adult nervous systems. Some scientists are reporting a surprising level of healing from treadmill therapy, which seems to teach stroke and spinal-cord injury patients to walk again.
(We'd add that neuroscientific dogma recently took a body blow from the cellular front: The brain actually makes new neurons over a lifetime.)
The promising results of early therapies, combined with images showing how training changes the brain, have forced calls a "sea change" in neuroscience over the past decade or so. That's how Jay McClelland, co-director of the Center for the Neural Basis of Cognition at Carnegie-Mellon University, describes the new interest brain plasticity.
See
change
It's hard to know where the field will wind up. We'd expect some promising
therapies to disappoint. And we expect to read of unforeseen, workable
treatments that use intensive practice to teach old brains new tricks.
The new techniques, McClelland says, may "apply to all different kinds of neurological conditions and more generally to any situation where people need to retrain themselves."
But
don't expect something for nothing -- since the mistaken dogma about the
inflexibility of adult brains does reflect the fact that their wiring
is generally quite stable -- and a good thing too -- otherwise we'd all
have multiple-personality disorder! "New learning does remain possible
in adulthood," McClelland says, "but it does require ... very carefully
crafted training, a real investment on the part of the learner. It doesn't
come for free, but there is hope for those who had no hope."
Behavior and experience can cause neurological problems -- but they also teach the brain to wire itself correctly in the first place, and may produce cures to troubling conditions. By exploring how to rewire brains through behavior, Merzenich says, "We can use the same forces that contributed to dysfunction to drive the correction. This unseen set of potentials offers substantial hope for the future."
Where's that bibliography again?
Bibliography | Credits | Feedback | Search