Physics on the brain
A report on a strange interdisciplinary
'If you can't explain it, quantum it.' That was how
Peter Fenwick , neuropsychiatrist at the Institute
of Psychiatry in London, began the day. He had brought together an unlikely
mixture of physicists, psychologists and psychiatrists to spend a whole Saturday
exploring 'The Science of Consciousness.'His words
were prophetic (could his brain have been using quantum effects to see into
the future?) or else he has come across the problem before. Consciousness
is a difficult concept and yet scientists from many disciplines seem to think
they can solve it.
Physicists are no exception: there have been many popularisations which end up speculating on how awareness emerges from the physical world. Yet when physicists, however intelligent or distinguished, apply themselves to consciousness they are more likely to finish by explaining one unknown by another than to come up with a solution.
The problem is the subjective nature of consciousness. Consciousness is more of a 'What is it like to be ..?' than a 'What is it?' question. But many answers at this symposium were a straight 'It is ..'
Ian Marshall, author (with Danah Zohar) of The Quantum Self [Ref:Protext Files;Video H1:"Soul"], suggested that the answer is a Bose-Einstein condensate [Ref: Audio:Alpha/Waltham:Science Now;Protext Files:SN1/5 ](or molecular oscillations integrated by high frequency electric fields). In his 'quantum brain model', he tried to explain the 'unity and order' of consciousness by analogy with the order and unity of the condensate.
Aside from the obvious weakness of building on nothing by analogy, there is the only slightly less obvious problem that consciousness is neither ordered nor a unity. For example, research with split- brain patients has led Michael Gazzaniga, a neuroscientist at Cornell University, New York, to conclude that everyone's consciousness is essentially multiple. And practices such as meditation (and many in the audience were meditators) reveal the fragility of the self and the disorder of consciousness.This did raise the interesting question of whether some kind of quantum processing could be going on in the brain, but most contributors argued that the brain is simply too warm and wet. I am tempted to speculate that graver problems have been overcome in the history of science - but even if this one were, the approach still does not get to the heart of the problem, the subjectivity of experience.
Non-locality is another favourite from quantum mechanics. Correlations in the behaviour of widely separated particles have been predicted and recently observed experimentally. Now consciousness is non-local. Well at least in a sense it is - it certainly cannot be said to have a position. But is this any more than just another weak analogy?
For Nobel laureate Brian Josephson, from the University of Cambridge, the link is from non- locality to telepathy - that claimed ability of people to communicate with each other without using the senses. He began his talk with the statement that telepathy is distance independent.
Leaving aside the weakness in the parapsychological evidence, this might hold out hope of a top- class physicist finally coming to grips with a paranormal phenomenon. It could even be that scientists have generally ignored the evidence for too long simply because we lacked an appropriate theory into which to fit it.
But can this really work? The crunch seems to be that non-locality does not allow for the transfer of information. It implies only distant correlations, and any apparent effect on individual events is lost in statistical averaging. To get round this Josephson takes a classic leap of the imagination and supposes that there is something special about living things.
Whereas science tends to specify form, living things deal with meaning. Their perceptual processes are not like the measuring instruments of the physicist, he claims.
But is this plausible? Now that biology has a good understanding of how living things evolve from the non-living this appeal to a fundamental difference between them seems misguided.
Nevertheless, If Josephson could make it work he might prove the majority of scientists to have had their heads well and truly buried in the sand over the paranormal. But even this would leave the mystery of consciousness untouched. Telepathy, even if it exists, even if it were explained, need not have anything to do with consciousness. Indeed, if it were explained it would lose the one thing the two do have in common - their incomprehensibility. So the problem of subjectivity remains as elusive as ever.
It was only Chris Clark, professor of applied mathematics at the University of Southampton, who faced this head-on. His leap was a daring but challenging one. 'Every entity has its subjective existence,' he claimed. Every entity? Does this mean stones and sticks too? And spiders and piles of beer cans?I think this idea is important. It sweeps away all the difficult questions about where consciousness begins or ends, who or what has it or doesn't, whether computers are conscious and so on. Where it runs into trouble is that entities are defined by our language. The world is not naturally parsed into 'things.' So it is hard to see how subjective experience can be divided up into pieces called entities.
My own preference is to take many of Clark's steps but to say it is the representations constructed by information-processing systems which have the subjectivity. This gets round the problem of defining entities but begs some very difficult questions about the nature of representation.
Perhaps we should leave that one for the philosophers, but the progress of artificial intelligence means that we'll have to face questions about the nature of representations. It is my guess (but then I've probably got my head in the sand too) that this is how we shall eventually come to grips with the problem. Subjectivity is not revealed in the collapse of the wave function. Equating consciousness with Bose-Einstein condensates or non-locality is not to face it at all. I learnt a lot about science from these eminent physicists but next to nothing about consciousness.
Because they didn't explain it. They quantummed it.
Susan Blackmore works on perception in the psychology department of the University of Bristol.
The Meme Machine by Susan Blackmore