In May 2009, Margaret Throsby interviewed Norman Doidge MD, research psychiatrist at the Columbia University Psychoanalytic Centre and the University of Toronto. Here are a few nuggets from the fascinating, 40 minute long audio interview on neuroplasticity:
a property of the brain which allows it to change its structure and its function as it goes along and what drives that change is mental experience. So, consciousness in some way or another can lead to the change in the micro-anatomy of the brain. It’s mental experience that is really in three kinds of situations which we like to think of as different but in fact they’re all part of the same movement. That is, when we sense and perceive we can change the structure and function of the brain, when we act in the world or move our bodies in the world, and when we think and imagine which we do in preparation for those actions, in all those actions, in all those cases, which in reality are functioning together in a kind of a loop, the brain is responding by changing its micro-anatomy, and it does so in the most remarkable way. The Nobel Prize in the year 2000 went to Eric Kandel for showing that as we learn we can increase the number of connections between nerve cell A and nerve cell B in an order of magnitude of, for instance, 1300 connections in a small area to double that in four hours of a session.
Neurosplasticity at this point is not a theory it’s a fact and the experiments have been done hundreds, even thousands, of times.
…we thought of the [brain's] circuits as hardwired, meaning that they were genetically predetermined to be a certain way, formed and finalized in childhood and that turns out not just to be wrong, but really spectacularly wrong because the brain not only can change its hardwiring, if you will, but that’s how it works, that’s its modus operandi and always has been. Now, there’s several reasons we didn’t notice it, one of them was because of the mechanical explanation, that we weren’t looking for it, the other one is that the plasticity itself gives rise to both our flexible and our rigid behaviors, as strange as that may sound. When neurons are trained they get very, very good at what they do. And it turns out that brain plasticity is a competitive property. So if you learn to speak in a certain way, pronounce words in a certain way, and then you move to a different culture, it’s very, very hard to change that because that behavior is overlearned, if you will, the neurons that teach you to pronounce those letters and words, it’s a coalition of neurons and each time you practice them, they become faster in firing and stronger in their signals and they dominate the linguistic map space, so plasticity gives rise to flexible and rigid behaviors. And these rigid behaviors actually mask our human flexibility. I like to describe it as plasticity is like snow on a hill in winter. If you ski down that hill, initially because the snow is plastic and pliable you can take many paths down that hill. If you enjoyed your first run, you’ll probably take your second and third run very close to that first one and develop tracks and runs in the snow because its plastic and pliable, and so plasticity masks itself.
The more I think about the brain, the more I think that it’s not really just in your head, if you will. It’s best understood as part of a nervous system that extends into our bodies and so it’s like our bodies and the body cannot be understood apart from the electromagnetic spectrum of energy that’s bouncing on and off it all the time. These things are all connected, so, we’ve become accustomed to thinking of the brain as sort inside the skull but it’s also in the body as well.
Dr. Doidge’s book is called The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science.