Wednesday, August 19, 2009

How Fast Can The Brain Re-wire?

The brain is in various states of readiness to re-wire in response to a particular learning experience. Changes at the chemical level, such as an alteration of neurotransmitter release, uptake, production, are very rapid. Changes at the level of connectivity between neurons such as increase in numbers of synapses (connections), strengthening of synapses and remodeling of synapses is also quite rapid. Re-wiring processes that incorporate newly born neurons into a pathway are somewhat slower to occur – these are the changes that lead to enlargement of brain areas that a heavily used for specific tasks.

Using a new brain scanning technique called Diffusion Tensor MRI, scientists can now trace connections between different brain regions and recent observations demonstrate that the microstructure of the brain can change in mere hours. After subjects were asked to train on a visual/spatial task, structural and functional changes were detected as soon as two hours of training. The spatial learning task involved playing a highly engaging race-track video game, going over the same virtual race track 16 times. Each time the subjects circled the track, the time they took to complete it decreased. At the end of the two hours, microstructure of the hippocampus, motor and visual areas of the brain had changed! These microstructural changes involved changes in connectivity between neurons such as increased synaptic density, formation of new synapses and formation of new dendrites.

But neurons are not the only brain cells that adapt to learning. The other type of cell present in the brain is the “glial cell”. Glial cells are essentially support cells – meaning they support the function and needs of neurons. Scientists recently found that new glial cells, which are produced in the brain throughout life, release a type of chemical that acts as a brain fertilizer - facilitating the growth and connectivity of neurons in the brain. This response of new glial cells was demonstrated to produce improved cognitive function in aging brains.

This all makes sense when you think of the speed at which cognition and attention have been shown to improve with training. We have witnessed some pretty remarkable changes in academic performance, social attitudes and behaviors of children using Neuropath Learning programs in just a matter of months which amounted to a total time of 8-10hours of interaction with our learning system. We have always found this pretty mindboggling to explain but in light of Michael Posner's work, I reported in an earlier post and this recent data we now know that the brain can and does adapt functionally and structurally at a rapid pace producing such dramatic outcomes.


References:

1. American Friends of Tel Aviv University (2009, August 17). Window Into The Brain: Diffusion Imaging MRI Tracks Memories And May Detect Alzheimer's At Early Stage. ScienceDaily. Retrieved August 19, 2009, from http://www.sciencedaily.com/releases/2009/08/090812145022.htm

2. University of California - Irvine (2009, July 22). Neural Stem Cells May Rescue Memory In Advanced Alzheimer's, Mouse Study Suggests.ScienceDaily. Retrieved August 19, 2009, from http://www.sciencedaily.com/releases/2009/07/090720190726.htm

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