Sunday, 6 January 2008

How the brain controls the body

Why is it that we (in the broadest sense of 'we') can build a computer that beats grandmasters at chess, but not a robot that manipulates a chess piece with the dexterity of a six-year-old child? And we don't even have any real idea how to start approaching this problem?

How, in fact, does the brain control the body? In this public lecture at the Royal Society, Professor Daniel Wolpert of Cambridge University explains that no-one really has a clue.

I go to scientific lectures whenever I can. I don't think I went to any in 2007 but it's time to start again. There are all sorts of wonderful things out there, and the ones where they tell you what they don't know are often profoundly interesting. This is one. The Royal Society video their public lectures and put an archive on their website, and they're quite often webcast live; you can see the calendar here, and you can subscribe to podcasts.

This is what I thought when I went to this lecture (in 2005 I think it was). There's a kind of spider called the bolas spider. It hunts for moths by making a lassoo of silk with a gob of glue on the end. It whirls the lassoo in the air with one leg, catches a moth, reels it in and eats it. The spider is the size of your thumbnail. How many neurons has the thing got? How does it control its body well enough do all this? Clearly, nature solved the problem of controlling extremely complex movement in an unpredictable world a very, very long time ago. By the time trilobites came along, it had been completely nailed for millions of years. Somehow, it must be simpler than it looks.

But nobody knows how it works. There is lots of data - but there's no theory, says Professor Wolpert. Watch the lecture for more.

He talks a lot about noise and how the nervous system deals with the unpredictable world (we don't know), why animals have brains and plants don't, and why it makes sense that Tiger Woods earns a lot of money.

On looking up the bolas spider, I read that it is very sensitive to vibrations, and responds if you pluck guitar strings at it. Did you know that Charles Darwin played the clarinet to worms, to see what they would do?

5 comments:

Jo A said...

Interesting. I mean that in the nicest possible way. I am tempted to play the clarinet at worms too, though it hardly seems fair on them.

Limerick Tango said...

Hey they can't even decide which comes first, thought or movement. Personally I subscribe to the theory that thought is based on movement, on the basis that the early natal period is spent going 'what is this moving thing?, oh it's a thumb'.
Therefore I like to think as little while tangoing as my body/movement is doing all the thinking.

Sallycat said...

Hi Ms Hedgehog.
From Buenos Aires back to England, I've passed the baton of the tango blog tag challenge on to you. Just you and Pysche, because I figure that the world needs to know a bit more about us folks for who England has been or still is home...
If this sounds a bit odd, read my latest blog.
Besos, Sallycat

msHedgehog said...

And why shouldn't worms get to listen to music?

I am not sure how the worms reacted. Do worms even have ears?

La Nuit Blanche said...

lovely post! i have always felt that i listen to music (well, sound) with my whole body, not just my ears. maybe certain frequencies (or the volume?) give off vibrations that can be felt in other parts of the body, besides our ear drums?

slightly off-topic, but this reminds me of how physical the experience of sound is, especially of making sound. when i play an instrument (the piano, the drum), for example, it is very physical, more akin to dancing, than listening...

anyway, i am sure the worms will be able to hear the clarinet, ears or no ears, hehe.