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Dan Dennett and my Quantum Proposition
Stephen Szanto on trying to combine the views of Roger Penrose and Dan Dennett on consciousness by what he calls his own modest proposition.
It all began at the end of March last year, when about fifty philosophers from six countries met in Budapest to discuss seventeen papers on consciousness for two days with the renowned Professor Daniel Dennett. Although I usually grab every opportunity to visit my native Hungary, particularly since our Russian ‘guests’ realised that they had overstretched our ‘hospitality’, this time I left behind the green and pleasant land of my home in Woodford Green with some trepidation.
This was because I wanted to talk about the possibility that consciousness in some way depends upon quantum mechanical effects in the brain. Dennett, however, rejects quantum mind-brain explanations in all shapes and forms, even if they come from famous Nobel laureates like the late David Bohm or internationally acclaimed scientists, like Roger Penrose. He calls all such theories ‘skyhooks’, after the airline pilot who just would not circle any longer on ground control’s order, telling them: “Listen, this machine is not equipped with a skyhook.” But when I warned Professor Boros, who organised the meeting, that there would be flack if I even so much as mentioned quantum mind-brain models, he thought this would make things only more interesting.
It was against this background that I began my paper with an anecdote that I heard from Professor Jerome Bruner. Bruner had two important effects on my philosophical outlook. First of all he liberated me, together with many other people engaged in medical research, from the boring yoke of behaviourism. Secondly, he swayed me, albeit only temporarily, from adhering to Dennett’s cognitive theories.
Up to the point of hearing Bruner’s anecdote, I was a faithful devotee of Dennett’s ‘Intentional Stance’ whereby we can understand other people’s minds if their beliefs, thoughts, fears, hates and loves, in other words ‘intentions’ are known. Later on, when he expanded this by his ‘Narrative Model’ whereby we live our lives by creating stories about it, I embraced it together with all those of my medical colleagues who already knew this from their daily practice. After all, our patients dream, remember, anticipate, hope, despair, believe, doubt, plan, revise, criticise, gossip, learn, hate and love by narratives. Their combined intentionalities and narratives do not just accompany but often actually constitute their illness. Narrative-based medicine is not the opposite of evidencebased medicine but rather an essential accompaniment. And if we are criticised for basing our diagnosis on their narrative accounts, we have now Professor Dennett to support our case.
From the corner of my eye I could just see how Dennett, sitting next to me, was beaming with approval.
But now I came to Bruner’s anecdote about his friend Niels Bohr, whose teenage son confessed that he was out shoplifting. “It was difficult,” Bohr said, “to know my son both at the same time in the light of love and in the light of justice. Could you have both love and justice at the same time and in the same psychological system?” And so, he claimed, this experience of moral complementarity had inspired him to develop his quantum complementarity in physics. I brooded about this for quite a while. Then one day, out of the blue came the revelation. I must unite Bohr’s quantum complementarity with Dennett’s cognitive ideas! What Mother Nature did was to give even to primitive unicellular organisms a quantum process. From this, getting to our human brains, where algorithmic computations, whether the sequential or the parallel (‘neural’) types, would rapidly and with smooth plasticity alternate with quantum states, could be explained as an evolutionary development. From a bird’s eye view, according to Dennett’s cognitive theory our current computers already give a pretty close approximation to understand consciousness. Being constructed of subsystems, each of which processes its own small and special task like a worker on an assembly line, consciousness eventually emerges when ‘gates’ (switching devices) are incorporated in sufficient numbers.
Together with many other perplexed seekers of the truth about consciousness, I could never quite come to terms with Dennett’s idea of completely abandoning the Cartesian Theatre. David Hume could not do it either, in spite of the fact that he was the first to suggest impressions, ideas, memories and imagination as ‘subsystems’ to explain consciousness. “Something, somewhere, somehow, just must unite them to explain awareness,” he struggled with the problem. Dennett is quite modest: “it was not I who found the answer to Hume’s problem, but one of my students. Hume’s trouble was that it did not occur to him that simpletons they might be these small subsystems, they can still ‘think’ their simpleton thoughts. It is their sum total that gives us the illusion of consciousness.”
Francis Crick of DNA fame will have none of this. “The feature hypothesised to form the underlying mechanism of awareness is locked neuronal oscillation in the 40 Hertz range. Dennett is sceptical about the helpfulness of neuroscience, as according to him human consciousness is too recent an innovation to be hard wired into the innate machinery. But this is very contentious as we do not know how recent human consciousness is.”
Yes, but what makes the individual nerve cells (neurones) to be locked together into unity? Well, with this question we arrive at the biggest problem of our consciousness-chasing: the binding problem. And for this the quantum explanation offers itself almost immediately as an obvious choice. It fits like a pair of gloves. We only have to think of lasers or superconductivity with their unified nature as the solution to the secret of their function.
Apart from explaining the binding problem, quantum theory could also explain qualia, that is, our mental awareness of states such as perceiving the greenness of grass or the shame of being offended. Dennett’s answer is simple: in his seminal paper entitled ‘Quining Qualia’ he says that qualia are an illusion.
To ‘quine’ is to deny something that appears to be real. Dennett coined the verb in honour of the highly acclaimed and respected philosopher, W.V.O. Quine who, according to my brief research never really denied the existence of qualia. Therefore, the advice that “don’t quine when Quine says not to,” seems to be appropriate.
Quantum consciousness, on the other hand, with its unified nature could explain similar unified mental states, such as states of gestalt in the mind, which just might include qualia also.
I glanced at Dennett; this time his body language was not supportive. “I must get him again to be on my side,” I thought. So I told him, together with about fifty others, that I was well aware of the fact that sceptical scientists and philosophers just would not buy all this at first blush. Neither would they be warming in favour of the quantum model if I would start referring to famous explanations, such as Bohm’s holographic mind-brain theory or Penrose and his co-worker, Stuart Hameroff’s microtubular quantum gravitation. Instead, I would try to persuade them that intracerebral quantum processes could be proved experimentally. The question is how can quantum states inside the brain be proved?
Our best chance for this at present is to apply the Copenhagen Interpretation of Niels Bohr and his associates, which postulates that the wave-particle quantum state can be mathematically described by its wave function. Any observation or measurement collapses this wave function into one of its complementary constituents. Accordingly, the reason why our non-quantum computers function on classical, nonquantum principles is that quantum processes cannot develop in a system undergoing measurement-like interactions with the outside world. Incidentally, the construction of inherently isolated quantum computers is theoretically possible, as shown by the Oxford mathematical physicist David Deutsch (see interview in Philosophy Now Issue 30). Whether or not such computers would be conscious is hotly debated, but this question was beyond the limits of my promise to restrict myself to experimental findings. Instead, I began to describe the first experiment that I knew of which demonstrated quantum effects within the human brain.
In 1994, in the first issue of the now well-established Journal of Consciousness Studies, with Professor Dennett among the Editorial Advisers, a team of researchers from Southampton University published their work as follows:
In order to collapse the wave function, electroencephalographs (EEG) were taken from 70 healthy human volunteers by attaching electrodes to their scalps in the usual way. The subjects did not know whether the electrodes were switched on or off. The goal was to see if switching on the EEG electrodes and thereby collapsing the wave function (i.e. to stop any possible quantum process) had any effect on conscious task performance. If the brain’s electric fields are non-quantum, measurements should have no effect. But if electric fields associated with thinking are quantum, measurements should collapse them with improved mental task performance, presumably because the quantum state became algorithmic.
Without going into details, the Southampton team’s results showed that their subjects’ task performance improved after taking measurements on the left side of their brains, but not on the right side.
Statistical analysis showed that the overall probability of these finding being due to chance was around 1 in 500, small enough to be suggestive but not conclusive.
My own view of this experiment is in line with the publishing journal’s editorial comment, which described it as ‘controversial’. After all, the experimenters themselves agreed that their statistics were not overwhelming. Also, apart from chance, there could have been non-quantum factors affecting task performance, such as local blood flow changes. The research team modestly and honestly admitted all this in their conclusion, agreeing that their results required confirmation by independent researchers. Nevertheless, personally I consider their work tremendously important by showing the way for further experiments. I myself intend to do this, but on somewhat different lines.
First of all I would wish to abandon the mental task performance testing, because in my view these depend on algorithmic computation. Our current sequential and ‘neural’ (parallel) computers can do such computations far better than we can, without showing any features of consciousness. Instead I would like to induce Crick’s ‘locked neuronal oscillations’, that is to study unified brain states. The most practical way to do this could be to study subjects in a state of deep meditation, with which most practising doctors are familiar by now. The effects of meditation on blood pressure, heart rate and in all kinds of physiological and pathological situations are well researched and published.
I searched the Internet and found that the general medical consensus for brain states in meditation was that of a low input and high attention state. This is an unstable paradoxical state, for usually when we cut off input to our brains, we also drop our attention. This is the usual procedure for going to sleep and also in hypnosis. Seen as a computer, the brain area involved tends towards a more stable state, not unlike the tendency for crystallisation in a similarly unstable supersaturated or supercooled solution. Even if this would be only a transient and momentary condition, it could bring about the mental process of ‘binding’.
The meditative subject’s experience described as ‘total unity and the feeling of certainty with complete awareness’ seems to describe such a mentally crystallised state. One particular article in the Indian Journal of Medical Research reported an EEG shift during meditation from the lower to the higher frequency range, which corresponds to Crick’s hypothesis with a frequency in the 40 Hertz (cycles per second) range.
My other modification of the Southampton experiment would be to measure regional cerebral blood flow, which nowadays can be arranged routinely and non-invasively by computerised imaging techniques. If this, together with the depth of meditation that can also be tested objectively, change by switching on the EEG electrodes to collapse the wave function, the presence of an intracerebral quantum state would be proved.
Presently this experiment is in its planning stage, but its description might give others some good ideas, of which I would be only too pleased.
Having said all this, I ventured to make some philosophical deductions based on the fact that Einstein refused to accept the two basic characteristics of quantum mechanics: uncertainty and non-locality. He expressed this by the famous remark that “God does not play dice.” To prove this he, Podolsky and Rosen designed a thoughtexperiment known as the EPR paradox. This was meant to show that certain quantum features such as non-locality, that is the permanent and instantaneous connection between particles even after their original connection has ceased, were incompatible with the limiting factor of the speed of light.
How the EPR thought-experiment was turned into the actual EPR experiment by the French physicist Alain Aspect, triumphantly verifying non-locality, is by now history. Two members of Professor Aspect’s team wrote a book afterwards called The Conscious Universe. By this they did not mean selfawareness in an anthropomorphic sense but rather as an abstract fact of nature “remembering itself as a unified whole”. (The Conscious Universe: Part and Whole in Modern Physical Theory, M.Kafatos and R.Nadeau, Springer Verlag, 1996)
If human consciousness could be proved to show quantum features, the philosophical statement whereby consciousness should be regarded as one of the fundamental and universal features of nature might be validly proposed.
For the sake of accuracy, I am quoting the conclusion of my paper word by word:
“And if I am asked how this would tie up with my declared commitment to Dennett’s evolutionary theories, I would refer to his book Kinds of Minds. In this, towards the end, he raises the question: what drives the evolutionary design itself? Coming from him, the answer is astonishing. ‘It is the abstract entity of the free-floating reason of its products’ own function’. Could this ‘abstract free floating reason’ be identical with the idea of a ‘universal consciousness’?”
I sat down, Professor Dennett joined the applause and said he liked my paper very much. Yes, but apart from sitting in the driving seat of current consciousness research, he is also one of the most charmingly courteous gentlemen I have had the pleasure to meet.
When I said during discussion time at the end of the meeting: “I think you practically agreed Dan, that my quantum mind-brain proposition could be incorporated into your cognitive theories, but please correct me if I am wrong”, he replied: “No, you are not wrong, Stephen. And I wish you luck with it.”
© Dr Stephen Szanto 2001
Stephen Szanto is a medical doctor and a philosopher.