Wednesday, 29 October 2008

Faceblindness, seeing in colours and metaphor

First keynote speaker was Professor Ramachandran, Director of the Center for Brain and Cognition, University of California, San Diego, talking about The Unique Human Brain: Clues from Neurology.

It was a fascinating talk, focusing on the complex structure of the human brain, and it's relevance to creativity and metaphor!

The human brain is the most complexly organised form of matter in the universe, with 100 billion neurones in the adult nervous system each making 10,000 points of contact. It's been estimated that the number of possible brain states exceeds the number of elementary particles in the universe. So - how do you begin to understand it? His technique is to study patients with tiny brain injuries which often lead to a highly specific loss of one function. One example he gave was faceblindness. A condition where people canot recognise faces, even of close relatives. Studying these patients has lead to the identification of the part of the brain which indentifies faces.

Another rare condition was one of his students who after a head injury thought his mother was an imposter - he couldn't recognise her face. A highly selective delusion with a number of freudian explanations. However, cognitive neurosciene has shown that it is a straightforward small brain injury where messages are not getting to emotional centre of brain from the visual recognition part.

A particular area of study is phantom limbs, where after amputation patients can continue to feel the limbs presence, often with excrutiating pain in them (as an aside he said that this phantom presence can happen when any part of the body is removed except of course the brain, unless you were a politician). Study of these phantoms has allowed the identification of cross wiring that has gone on in the brain, where the lack of signal from one part of the body to its area of the brain allows that area to be "invaded " by another area and signals misinterpreted as coming from the arm – even though it’s gone. A radical change in the pathways of brain. His hypothesis was that the brain is in a constant state of dynamic equilibrium with the potentail for pathways to be changed and adapted.

The final area he covered was Synesthesia - a condition where people see things (often numbers) in colours and hear music as colours. This runs in families and is more common in artists, poets and novelist.
There are many theories to explain this– the patient is mad, high on drugs, reliving childhood memories, or just being metaphorical. But it is a concrete sensory phenomenon and he has shown that the part of brain processing colour is right next to area which processes numbers and that some cross wiring has occurred. It's a genetic phenomenon, and happens when there is a fault in "pruning genes" which operate in the foetus to correct misconnections in the brain.
Some people see days of the week, months etc as colours and this is caused when the cross wiring is higher up.

The excess connections caused by the synestheseia gene makes people more creative - artisits, novelists etc are all good at metaphors. That’s why this seemingly useless gene has survived. and the reason not everyone is synesthetic - you don't want everyone to be metaphorical and creative - especially neurosurgeons! A diverse set of skills is needed.

I really enjoyed this talk - took me back to being a genetics student again! I liked that fact that he made it clear that he did not believe in intelligent design, but in evolution. His final comment was that it was ironic that the President was championing intelligent design when his own existence was a living negation of it!

A video of the session is here

2 comments:

Pablo said...

Interesting, and great that he wasn't comparing the brain to a computer.

Vaguely depressing though that he felt he had to say he didn't believe in Intelligent Design. What about Santa Claus? Strange country (but where isn't I guess).

Chris Sexton said...

Ah, but most intelligent people know that Santa Claus doesn't really exist - over here the same can't be said about Intelligent design!