Wednesday, 18 March 2009

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, t
he 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.


Gorilla Bananas said...

What's your theory as to why people who are gifted in languages and verbal expression are often weak at mathematics? How good are you at maths, by the way?

circular_fish said...

There has always been an interesting divide between hardcore neurologists and the seemingly more wishy-washy neuropsychologists and it's interesting to see the former coming round to the latter's point of view.

A classic example of this divide can be seen in the differing reactions to the excellent (and frequently chain-emailed) study by Simons & Chabris (1999). "Gorillas in our midst: Sustained inattentional blindness for dynamic events." Psychologists are much less functionally reductive than their 'hard science' colleagues who fail to comprehend how the neurological machine can process information without consciously realising it.

Anyway, I digress.

Psychologists have believed and been interested in neuroplasticity since the early days of Broca and Wernicke. Whilst their experiments and findings also lead to the development of stringent double-dissociation methods, they also kick-started the notions of plasticity and how the brain can, if not repair itself, circumvent 'dead' areas.

The exciting thing about neuroplasticity being studied further, is it is much closer to dealing with the big question psychologists and philosophers have toyed with - the exact nature of the Ghost in the Machine.....

That said, the less said about any use of psychoanalysis as an attempt to remap or reassociate experience, the better. Just because cognitive associations have been rewired, does not mean the emotional responses are removed.

Oh, and Gorilla're touching on an even more simplified debate than nature/nurture with your question... Left brain/right brain lateralisation.

Gorilla Bananas said...

That's an impressive collection of words, circular_fish, but it doesn't answer either of my questions.

Phoenicia said...

Well...This question is probably too complicated to be answered by me, but again, I'd say it depends.

I think most people take the easy (and again, highly reductive) argument that we're either right brained or left brained and that's that. If you're more apt at mathematics or logical thinking, you get a left-brained gold star; if you're an artistic soul, who scribbles poetry during your lunch hour, we put you in the right brained box.

Fine, but most people I know don't have a severed corpus callosum...

Again, this is a very simplistic argument, but I'd say that just as with music or sports or mathematics - our formative childhood years can establish quite a few trends of our adult life. Of course this isn't to say that I don't think changes can't be made in adulthood, but certain cultures value certain characteristics more than others - which ties back into the brain and culture relationship being firmly two way. If you grow up in a family of accountants or engineers, you're more exposed to this way of thinking from a young age or if you're brought up speaking two languages as a child, you're strengthening language areas earlier on and more so than numerical areas.

Again, use it or lose it comes into play as well. Part of being 'gifted' at anything is via repetition, experience, and practice - maths and/or verbal skills are no exception. Sadly, I think the educational model has a lot to account for the maths/language divide. If a child shows particular aptitude for a certain skill, this tends to be targeted and strengthened: no bad thing. But unfortunately other areas of learning may then fall by the wayside as this one area (reading or maths or whatever) is consistently exercised.

Childhood development, educational entrenchment, and adult laziness. There. Happy?

Once upon a time, I was quite good at maths, but I'm quite out of practice nowadays. American Unis require even Humanities students to take at least two years of maths and I also took quite a lot of maths-heavy science courses. I also tend to score quite well on those spatial aptitude tests which only men are supposed to do well on. Engineering, here I come!

Francisco Castelo Branco said...

nice contribution

Justin R. Wright said...

Your writings are fascinating.