Saturday, December 22, 2007
Waiter, there's a wire in my soup!
That the brain is hardwired or softwired is one of those half truths that drives the wires in LI’s own brain haywire. The idea that the nerve is a wire goes back, as we have shown in various previous posts, to suggestions made by Newton, and taken up in the eighteenth century by people like Hartley. Although strictly, the metaphor then was more of a kind of string imparting pulses, or vibrations. Galvani’s experiments suggested that the nerve was the locus of animal electricity – it was like the wire coming out of a Leyden Jar.
Now, in truth, there is no wire that I meet up with in the course of my day to day encounters with electricity that is like a nerve. The string idea, of course, still exists in the notion of nerve ‘fibers’ – which is only to say that the way in which the nerve had to be modeled on artifices of human manufacture as it was understood goes deeply into the way nerves are talked about. On some level, we are all naturally Hollywood voodooists – we make little dolls and explain human beings on the basis of those little dolls.
However, though fibers are what one might call a built in metaphor – they have become parts of the way that nerves are described - wires are not – wires retain the status of an external model to which nerves are compared. Saletan’s recent racist article at Slate about how whites are smarter than blacks, the one in which he based his science on the work of two well known racists and then backed off, due to the fact that he, in the five minutes of omniscience that he’d given to the subject, had neglected to review any of the literature on the subject, provoked a huge and hugely stupid discussion of IQ and genes, with the assumption that genes are the thing we should look to to explain our mental life. Genes, we are assured, either hardwire or softwire our brains. In fact, our brains have been examined for a long, long time by neurology, and if we want to understand human intelligence – something that is much different than IQ, which is the result of a very early twentieth century textual invention called an IQ test – we should look to what the neurological sciences say. In other words – the underlying notion that genes determine the way the brain is ignore the fact that the way the brain is is highly and necessarily plastic; and that plasticity is expressed in the constitution of the neural network. We have wiring systems that primitively approximate this – routers in a telephone system can connect x’s call to y via one group of telephone wires or wireless transmissions or another. Selection, here, also primitively embodies something that happens in the selection of neural pathways, in that the number of calls can select out one route over another – that is, the router can use some algorithm to determine if too much use is being placed on one pathway and route a given call to another pathway.
But the whole router/wire thing, here, not only lags behind the complexity of the brain, but it leads us to misunderstand the basic distinction between nerves and wires: nerves are made of discrete nerve cells. The junction between them is a synapse, where chemical mediators bear the impulses. The image of the wire has been the basis for two historical misunderstandings in neurology. The first was the dispute between Ramon y Cajal and Golgi about the structure of the neuron – with Ramon y Cajal rightly understanding neural cells as discrete from one another, and Golgi holding onto an older, continuous hypothesis, with the nerves imagined as things like wires – and the second, as Valenstein, in his history of neurophysiology in the twentieth century, puts it, was the “war between the soup and the sparks” – with those who dismissed chemical receptors, or the “sparks’ group, unconsciously bending their model to the model of the wire, Newton’s vibrations translated into Galvani’s electricity. Of course, the soup won – but oddly enough, we don’t talk about hard soup and soft soup. Although, indeed, that would be a better metaphor – but it would make the body seem more like something whipped up in a kitchen than engineered by Edison. I needn’t go into the masculinist anxieties that such images conjure – we can see them all around us, can’t we?
In actual fact, the direction of influence is now going the other way – we are developing wire networks that are more souplike, so that we no longer speak of wires. But these archetypes of engineering still litter our ordinary discourse.
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Merry Christmas, Roger, peace...
ReplyDeleteahfukit, and shalom to you, sir!
ReplyDeleteFirst off Roger, happy holidays and thanks for another year of writing. It has helped me to stay sane in this madness and is one of the few reasons I'm looking forward to the new year.
ReplyDeleteI think that you might find the work of the biologist Steven Rose interesting. I've been reading his slightly dated Lifelines, but am working my way forward to his more recent book on the brain. The LRB had this review by Ian Hacking (appropriately enough it's called "Get Knitting"):
http://www.lrb.co.uk/v27/n16/print/hack01_.html
A choice quote that I think fits in with you musings here:
"We should start at the beginning of the life of a human being, and trace the way that an egg becomes a person. A new design problem comes along. An incredibly complex organ, the brain, along with the rest of the body and its nervous system, has to grow in the womb and to continue growing through childhood, starting from nothing much more than a set of instructions. The egg, then the foetus, then the infant, develops into a fully brained human as the skull and its contents grow in a world rich in experience of people and things. The infant brain weighs 350 grammes, the adult one at least 1300 grammes, although it reaches 95 per cent of its adult weight when a child is ten. And most of the growth happens in the first two years.
To a certain extent the first stages of brain formation for a human being will have to recapitulate the evolutionary progress: it would be absurd to postulate two different ways of achieving the same structure. But much else besides will contribute to the manufacture of a single body with a brain from virtually nothing. Rose is fully content to say that a newborn is not quite human (which has nothing to do with rights to life and care). It is born half-hatched, at a developmental stage midway between that of mice and that of guinea pigs. The latter have fur and run after their mother the moment they leave the womb, while newborn mice are roughly as developed as premature babies born early in the third trimester. Rose’s attitude is clear: to be fully human does not mean merely possessing a brain that weighs at least 1300 grammes. The brain also has to become part of a social person."
As the recent Saletan brouhaha suggests, there is an emergence of a new social darwinism, shorn of its more overly racist and eugenic features, as a new ideological supplement to neoliberalism. It's going to become increasingly important to understand and combat evolutionary psychological and sociobiological explanations of inequality.
Cheers,
HerrVonHarmonia
Damn right, HVH! It is one of the funnier parts of the debates on gene reductionism that it an organism would be incredibly vulnerable if it depended completely on its genes to kit it out. It would be like, well, having to wear the same set of clothes you wore at three all your life. There is a good evolutionary reason that we aren't one hundred percent dependent on our genes for our traits - we live in drastically variable environments. This isn't emphasized enough, I guess.
ReplyDeleteI don't know where LI stands on Antonio Damasio, but to echo what you wrote above, he notes in Descartes' Error the genome just isn't large enough to provide a complete specification of the anatomy of a brain. And I realize that when I write "specification" that I'm slipping into the same engineering vocabulary and figures of thought that can get us into trouble in the first place. But —gulp!— when all you have is a hammer, it's not that everything looks like a nail but rather that you can only treat it like a nail.
ReplyDeleteBest of however you chose to conceive of this season,
—et alia