Research #1: Brain Mapping
Recently researchers Michael Merzenich and colleagues were able to induce cerebral palsy–like symptoms in the hindlegs of rats. They did so by tying the two hind legs together at the time the rats were born so they always moved the two legs together as one. After a while, when the restrictions on the legs were removed, the rats continued moving them together as if they had only one leg, just like Kassi. Their brains had mapped the legs as one, not as two: Merzenich and his team at the University of California San Francisco show the importance of what he terms randomized movements, what we term random movement.
Coq, J-O., Byl, N., Merzenich, M. M. 2004. Effects of sensorimotor restriction and anoxia on gait and motor cortex organization: Implications for a rodent model of cerebral palsy. Neuroscience 129(1): 141–56.
Coq, J-O., Strata, F., Russiera, M., Safadic, F. F., Merzenich, M. M., Byl, N. N. and Barbec, M. F. Impact of neonatal asphyxia and hind limb immobilization on musculoskeletal tissues and S1 map organization: Implications for cerebral palsy. Experimental Neurology Volume 210, Issue 1, March 2008, 95-108.
Marcuzzoa, S., et al. Different effects of anoxia and hind-limb immobilization on sensorimotor development and cell numbers in the somatosensory cortex in rats. Brain and Development Article in Press, Corrected Proof Available online 24 May 2009.
Research #2: Movement with Attention
Research shows that movement done automatically creates little or no new connections in the brain: “[T]he variable determining whether or not the brain changes is . . . the attentional state of the animal.”
Schwartz, J., Begley, S. 2002. rpnt 2003. The Mind and the Brain: Neuroplasticity and the Power of Mental Force. HarperCollins.
In experiments with owl monkeys Merzenich’s group demonstrated a clear correlation between the power of attention (to the feeling of the movement being done) and the brain’s ability to change itself:
Recanzone, G. H., Merzenich, M. M., Jenkins, W. M., et al. 1992. Topographic reorganization of the hand representation in cortical area 3b of owl monkeys trained in a frequency discrimination task. Journal of Neurophysiology 67: 1031–56.
Nudo, R. J., Milliken, G. W., Jenkins, W. M., Merzenich, M. M. 1996. Use-dependent alterations of movement representations in primary motor cortex of adult squirrel monkeys. Journal of Neuroscience 16: 785–807.
Doidge, N. 2007. The Brain That Changes Itself. New York: Viking/Penguin.