the brain that changes itself

I got into an argument with The Boy a few days ago about 'super-stringy' calf fibres (his terminology, not mine - I think they're actually called fast or slow twitch fibre compositions). While I'm all for interdisciplinarity, my entire academic career testifies to this claim, attempting to overlay anthropological theories onto neuroscience just doesn't work for me. Basically he was trying to argue that nature presided regally over nurture.

Being, as I am, mildly obsessed with neuroscience (I'm already planning a career change at 37) I know that most neuroscientists, but especially those with a particular interest in neuroplasticity would say that the nature/nurture debate is largely irrelevant as the two are completely inter-related.

Not only with sports, but with your ability to play a musical instrument, or to paint or compute complex mathematical equations - natural talent or genetics can only take a person so far. So yes, perhaps Michael Phelps is 'built' with the 'perfect' frame for swimming (whatever that means), but if he was more motivated to study theoretical physics and became one of our greatest physicists, no one would say 'he was built' for theoretical physics. Likewise, while proponents of the nature theory might argue that Lance Armstrong is a great cyclist because he has one of the greatest V02 max readings ever seen (an individual's maximal rate of oxygen consumption), the same genes that are so often attributed for his success also contributed to the development of his nonseminomatous testicular cancer.

I'm coming at the elite athletics side of this from a strictly laymen position, but after a little bit of reading, I found something interesting about the natural gap between V02 max readings between men and women. Sports physiologists supposedly claim that genetics play a major role in a person's VO2 max and that heredity can account for up to 25-50% of the variance seen between individuals, thus leading us to believe that nature triumphs over nurture and that plastic change is impossible. Where this becomes interesting is in a comparison between untrained girls and women, who typically have a maximal oxygen uptake 20-25% lower than untrained men. However, when comparing elite athletes, the gap tends to close to about 10% and if V02 max is adjusted to account for fat free mass in elite male and female athletes, in some studies the differences disappear. So something else is going on here besides just genetics. Training, nutrition, psychology, etc., must account for the ability for our bodies (and brains) to major changes.

It's always in running - especially sprinting - where people tend to say that speed is without doubt the result of genetically determined factors meeting training effects. Common belief is that if you took a random sample of children from West Africa and another from a western European country, on average, the West Africans will be faster in a sprint race. Explanations for this can not be precise, but tend to centre around natural ability and physiological determination.

Now to get to the whole point of this post. I recently purchased a very interesting book by psychoanalyst Norman Doidge called The Brain That Changes Itself. By some brilliant coincidence The Philosopher discovered that Dr. Doidge was giving a talk at LSE last night. We went, we listened, we were entertained. It was interesting - he wasn't as lucid in person as in his book (which I thoroughly recommend if you have any interest how your brain is profoundly affected by your everyday environment - you'll never look at porn websites again!), but still it was good fun.

The point about running and the difference between Africans and Europeans reminds me of a great anecdote in Doidge's book. In 2003, researchers from Sweden's Lund University did some research with the Moken sea gypsies who live in the archipelago of Burma and along the West Cost of Thailand. When you dive underwater and open your eyes, everything appears slightly blurry. Focusing depends on the curvature of the lens and the difference between the index of refection of the eye and the surrounding medium. Air has an index of refraction of 1, the cornea 1.376 and the aqueous humor 1.336. The index of refraction of water is about 1.33. Because of the small difference in the index of refraction of water and the eye, the lens must become very curved to focus light on the retina. Living on land, there was no evolutionary need for the lens to become this curved, so objects are out of focus when we open our eyes under water.

Unlike most of the rest of us, the sea gypsies maximally constrict the pupil to see accurately underwater - this is not a genetic attribute - rather it has developed over time through repeated exercise and use. Moreover, there are studies which have demonstrated that European children can learn to demonstrate this same pupil constriction with practice. This is a great and easy to understand example of plasticity and the 'use it or lose it' theory of the brain: we're talking about use-dependent cortical reorganisation here. This isn't saying that if you believe in something enough you can do it or master it, but that if you create an environment where you are constantly having to exercise a particular function in order to improve, then surprising things are achievable.

If I can be asked, I'll write up a part two sometime soonish. There are some very interesting connections between behaviour and environment (remember the porn?) that will seriously get you thinking about the habits which form your day to day existence. We may not have the inclination to be world-class athletes, but surely we'd all like to be a little bit better at something.

Like Doidge says, use your brain or lose it. And with new(ish and admittedly slightly hysterical) studies showing that age-related cognitive decline beings as early as 27, I'm pretty sure that means all of us could stand to do a bit of brain spring cleaning...

PS If you are really a glutton for punishment and want to know more - V.S. Ramachandran, a brilliant neuroscientist, gave the BBC Reith Lectures in 2003 which are very stimulating yet quite approachable.