In 1783, an Italian anatomist named Michele Vincenzo Malacarne studied the impact of exercise on the brain. He took pairs of birds from the same nest and subjected one pair to intense training, the other pair to none. He then conducted the same experiments with dogs: one pair got the enrichment of intense training, and the other pair got no stimulation. When the animals were euthanized, Malacarne found that the brains of stimulated animals were larger than those of their counterparts, and especially in the cerebellum – the part of the brain that governs motor control and coordination. And 165 years later, Jerzy Konorski, a Polish neurophysiologist, used the terms brain plasticity and neural plasticity in a book he wrote in 1948: Conditioned Reflexes and Neuron Organization.
Today neuroplasticity is generating a lot of excitement in areas of rehabilitative medicine, where good news is rare. Norman Doidge chronicles in one of his documentaries some of the promising research being conducted. Jeffrey Schwartz, an associate professor at the UCLA School of Medicine in California, for example, is using what he calls “self-directed neuroplasticity” in treating obsessive-compulsive disorder (OCD). The classic example of OCD is the person who can neither stop thinking about germs nor stop washing his hands to kill germs. Schwartz is deploying the principles of neuroplasticity to forge new pathways in his patients’ brains. His patients are learning firsthand that the brain can change its structure in such a way that the impulses can be recognized as just that — mere impulses. The physiological changes that accompany this mental shift are visible on their brain scans.
Alain Brunet, an associate professor in the Department of Psychiatry at McGill University in Montreal, is using the malleability of the human brain to treat people suffering from posttraumatic stress disorder. These are victims, for example, of rape, child abuse, car accidents, and hostage takings for whom the event remains very much alive in their minds. Brunet is reporting success using a blend of pharmacology and neuroplasticity. These patients are first given medication to dampen the emotion associated with these memories and then asked to repeatedly recall the event. These men and women are rewiring their brains, disconnecting the circuitry linking the memory of the event to the arousal of their own threat systems. This process allows each person to file the memory in a new folder in the brain, not in the virtual present but in its rightful place — in the actual past. This is the principle of neuroplasticity in action: neurons that fire apart, wire apart. These new treatments for trauma usefully exploit this fact: when you remember a traumatic event, the network for that memory enters a more malleable state, and the treatment proceeds in that heightened neuroplastic milieu.
Finally, researchers in California are using cognitive exercises to help those with schizophrenia address some of the cognitive problems associated with their condition. Such people have difficulty perceiving, processing, and remembering information, and neuroscientists Sophia Vinogradov and Michael Merzenich are using specially designed computer programs to improve these cognitive functions. Brain imaging, their research shows, has demonstrated that these cognitive exercises change regions of the prefrontal cortex — those involved in regulating attention and problem solving — of a person with schizophrenia so it begins to look more like a normal brain.
In addition, a protein in the brain called BDNF (brain-derived neurotropic factor, also known as the “brain’s fertilizer”) is typically low in the brains of those with schizophrenia. Critical for neuronal survival, BDNF is also believed to play a vital role in what neurologists call activity-dependent plasticity (a term used to describe the brain’s ability to change as the result of specific sustained stimulation). These exercises increase BDNF levels to normal — further evidence of neuroplastic change.
“We know the brain is like a muscle,” says Vinogradov. “If you train it in the right way, you can increase its capacity. The brain is ever changing in relation to what’s happening to it. With the correct training, we can improve cognitive processes that weren’t strong to begin with by improving the processing pathways.” Says her colleague, Dr. Merzenich, “The brain changes — physically, chemically, functionally.”
“It’s unrealistic,” Norman Doidge told me recently, “to expect that the definitive demonstrations of neuroplasticity in the laboratory will suddenly undo the doctrine of the unchanging brain that so many were taught. Intellectual revolutions require time to spread. In the meantime, those few who have understood that neuroplasticity has immediate applications face incredulity or even opposition. That is what happens when you are at the cutting edge. It’s lonely out there. But a lot of the opposition to the idea will pass generationally because in the last few years, all the major neuroscience texts have chapters on neuroplasticity. I’m not worried about its clinical acceptance in the long term.”
From The Woman Who Changed Her Brain. Copyright © 2012 by Barbara Arrowsmith-Young. Foreword © 2012 by Norman Doidge, M.D.