In the last couple of decades, mostly from the work of Michael Merzenich, neuroresearchers have begun to understand that the brain is not rigid, rather is plastic and capable of change until the day we die. In fact, back in 1949, Donald Hebb was the first to propose that learning linked neurons. He suggested that “when two neurons fire at the same time repeatedly, chemical changes occur in both, so that the two tend to connect more strongly,” (Doidge, 2007, p. 63). Michael Merzenich, one of this country’s most renoun neuroscientist today, expanded on this by saying that strong connections are made when they are activated at the same time.
He explains that when “we perform an activity that requires specific neurons to fire together, they release BDNF” (p. 80), (brain-derived neurotrophic factor) a growth factor which helps neurons to wire together so they fire together in the future. BDNF also helps with the myelinization of the neurons to speed up the impulses (Doidge, 2007).
The brain does not like change. Therefore, in order for changes to take place in the structure of the brain, we need to have access through all the senses, including the proprioceptive receptors of the muscles. In addition, the brain needs to be engaged, there needs to be repetition, or rehearsal of activity, and feedback to the brain is necessary. It is said that it takes exactly 3 weeks, 21 days, for connections to be made in the brain (Gold, 2008), so consistent repetition is necessary until the appropriate connections are made.
Cognitive and motor exercises are both extremely useful in changing the brain’s structure and thus improving learning, however younger children will make much faster progress than adolescents or adults because “the number of connections among neurons, or synapses, is 50 percent greater than in the adult brain” (Doidge, 2007, p. 42). The younger the child, the quicker the response and the better chance for a more complete recovery.