Rene' Descartes in about 1650, when Descartes posted two substances, Res Extentsa and Res Cogitans. Res Extensa is to be the material, and for Descartes the mechanical world of gears and direct physical causation in which the human body which was thought as a machine. With Newton's laws in differential equation form, initial and boundary conditions, Descartes' machine became the deterministic trajectories in the prestated "state spaces" of classical physics. Res Cogitans is the world of the "mind", brieflly, our subjective conscious experiences, or what philosophers call "qualia".
dierk schaefer/via flickr
Can we use quantum mechanics to understand how our minds can act on matter?
dierk schaefer/via flickr
Since Descartes, three central problems have plagued our thinking about mind and matter: 1) How can mind act on matter? It seems that the current state of the brain is sufficient for the next state of the brain, so there is nothing for mind to do. And there seems no way for mind to act on matter anyway. 2) How can we have a morally responsible free will? 3) The "hard problem", what is consciousness, after all? Three and a half centuries of trying have produced no satisfactory answers to any of these questions. Indeed, John Searle, a famous philosopher of mind, has famously quipped, "Not only do we have no idea what consciousness IS, we have no idea what it would even be like to have an idea what consciousness is!".
Notwithstanding three and a half centuries of difficulty, in the next three blogs, I will propose what I take to be the start of answers to all three questions. I follow Roger Penrose who first suggested in his "The Emporer's New Mind" that consciousness has something to do with quantum mechanics. However Penrose ties his attempt to quantum gravity.
I will take a radically different approach: To issue 1) I will propose in this blog that mind and brain are "identical", but that the total system is both quantum and classical, more that it is a system poised in a realm between persistent acausal decoherence from quant;um choherence partially or completely to "classicity", and recoherence partially or completely to quantum coherence. Thus, quantum mind can have consequences for classical matter acausally, without acting on causally on matter.
In principle, this answers "how mind can act on matter",. It does doesnot act causally on matter, but can do so acausally by acausally losing phase information from the mind-brain system to the environment, hence decohering from the quantum "mere possibilities" to classical matter. I will present below the evidence, theoretical and now experimental that supports this possible poised state of the mind-brain system, reversibly decohering and recohering from quantum to classical and back.
In the next blog, I will confront the familliar dilemna: If the mind-brain system is determinsitic, we have no free will at all. If the mind-brain system is sometimes quantum, hence purely random on any interpretation of quantum mechanics, then we are not morally responsible for our random actions. I will show that a partially decoherent-recoherent mind-brain system is almost certainly lawless in its detailed behavior, that that behavior can nonetheless yield historical behavior that is highly non-random in its historical "becoming" and that there is an interpretation of my hypothesis for the poised mind-brain system which allows the system to "decide" and acausally yield specific classical behaviors. This will be my basis for a morally responsible free will. I emphasize that at this stage it is more important to conceive of a possible answer than to be right in scientific detail.
In the third blog I will make the concrete suggestion that conscious, the hard problem, can be solved if we identify this poised quantum decohering-recohering mind-brain system with consciousness itself. I will propose speculative, but possible and ultimately testable identifications of this hypothesis with specific neural correlates comprised of the neural transmitter molecules in synaptic vesicles, and/or the post-synaptic receptors for those neurotransmitters and/or transmembrane ion and other channels on dendrites and nerve axons. Again any possible hypothesis, particularly testable ones, can hope to be more helpful than Searle's quip above.
As a scientist, I think my hypothesis, at present, is "just possible", but certainly improbable, ultimately testable, and may be the most hopeful and investigatable set of hypotheses we now have .
The last paragraphs are brave language. Here is why I do not like the reigning best hypothesis, which derives from the view of the mind as algorithmic: I do not think the mind is algorithmic! I discussed this in my last blog, "Is The Human Mind Algorithmic?"
A cogent discussion of the algorithmic view is put forward by Daniel Dennett in "Freedom Evolves", a fine book. Dennett rightly notes that John Conway's famous Game of Life, played on a large square lattice that can grow indefinitely in size as specified in a moment has the following properties: 1) The cellular automata rules of the game of life define for each square on the lattice its next state as a definite, defined logical, or Boolean function of the eight neighbors to that square and the square itself. All squares have the same logical rule. Each square can take the values 1 or 0, "white" or "black". We therefore know completely the "physics" of the completely deterministic system in which all squares update their values, 1 or 0, simultaneoujsly each time a discrete imaginary clock ticks. 2) Conway showed that the game of life could give rise to patterns of black and white squares, called gliders, which propagate across the lattice. The speed of the gliders moving across the lattice constitutes a "speed of light" in this physics and for our purposes, the size of the ever finite lattice need merely increase as fast or faster than this speed of light for the remaining results. Next, glider "guns" can emit gliders. Finally, an wonderfully, Conway showed that these gliders and guns could constitute a universal Turing machine!
Now, recall the famous "Halting problem" in computer science. Here the issue is that we want an algorithm which can examine any other algorithm which is to compute an answer, print it and halt. Our hoped for examining algorithm is asked to say whether the examined algorithm will halt in finite time as it works on its infinite Turing machine tape. Turing famously proved that the Halting problem is formally undecidable! That is, we cannot have a formal procedure, that is, an examining algorithm, which can say ahead of time what the examined algorithm will do, halt or not halt. The essential result is that, although we know completely the underlying Boolean function,or "physics" of the Game of Life on the growing two dimensional lattice, we cannot say ahead of time what the behavior of the every growing lattice will be.
The above remarkable result, firmly proven, is the posterchild for "emergent" behavior. And indeed it is emergent behavior: Once we have the above, the behavior on the growing lattice cannot be deduced from the underlying deterministic physics. Wonderful result.
Nevertheless, reducible to the underlying physics of the Game of Life or not, Dennett's Turing machine glider and glider gun system remains perfectly algorithmic!
What is wrong with this beautiful emergence as a model for mind?
I see an enormous pair of problems, despite Dennett's attempt:
1) As I argued in my last blog,"Is The Mind Algorithmic"?, the mind is not algorithmic. I refer the reader to that last blog, but briefly: Can you finitely name all the uses of a screw driver?
2) And is there a mathematics in which all those uses are theorems! I surely do not see such a mathematics. And if not, it is not true that everything that unfolds in the universe is mathematizable. If you object that here we assume a responsible free will for the possible uses of a screw driver, well yes I do. But the same is true for the emergence of Darwinian exaptations in the biosphere 2 billion years ago where we need no appeal to conscious thought at all. That unfolding becoming of the biosphere, I claim cannot be finitely, or even denumerably infinitely, prestated, nor can it be mathematized. The becoming by Darwinian exaptations cannot be denumerably infinitely prestated because to do so we would need an effective procedure to create an ordering relation, like the integers, listing the first, second, third...to infinity possible preadaptation, but in "Breaking the Galilean Spell" I think we agreed that we cannot prestate all the possible Darwinian exaptations into the Adjacent Possible of the bisophere. It seems we can have no ordering listing of those unnamable possibilities.
With respect to 1) above, can you finitely, or denumerably infinitely, name all the possible uses of a screw driver, I think you cannot. Watch: The screw driver can be used to screw in screws, pop open paint can lids, wedge doors open, wedge doors shut, peel putty, used to stab an assailant, tied to the end of a bamboo pole to spear a fish, used with a rock to chop down a (small) tree, leaned agains a wall with the flat side of the tip of the screw driver at right angles to the wall, and used to prop up a square piece of plywood leaning against the wall and supported by the screw driver from falling on a valuable pot,.....
Notice two features of the above. First, relational features matter in most cases above, for example the angle of the screw driver to the wall, and its being turned properly to support the square plywood board. To prestate both all the possible relational features of the screw driver with all entities in the universe from, say atoms to molecules to plywood boards and brick, to fish....from two to many "things" at a time, and simultaneously to prestate all the uses or purposes to which the screw driver can be put, seems impossible. Certainly if spacetime is taken as continuous, it is second order infinite, and no finite list of relational features is possible. no finite or even denumerably infinite list is possible, for, again, no ordering relation among the above, a first, second, third, use of a screw driver, can be devised. How would we create such an ordering?
As I argued in the previous blog, what computer scientists do is list a finite set of "affordances" of screw drivers, "is a", "does a", has a", "needs a", and do neat things. But if the weird use we or James Bond or McGiver wishes to make use of the screw driver to accomplish is not deducible from those affordances, then there is no algorithmic way to get to such uses. My claim is that not all possible relation features and uses of screw drivers can be deduced from any finite set of affordances, nor is there any mathematics that can entail all such relational uses, but we humans, in particular Bond or McGiver in a pinch, find the inventive uses all the time. The mind is not algorithmic.
If not, we have, as yet, no theory of mind.
I think a deep issue arises here: I am claiming that something is impossible, but have not proved it. Is it possible to prove such a claim about no ordering being possible? I don't know how. And I will take two lines with respect to this.
First, it may be what philosophers call a "category mistake" to seek a mathematical proof from that which is not open to mathematical proof. Maybe we just need to think.
Second, I have and here again suggest that the co-evolution of the quantum-classical system in its environment is beyond law, hence cannot be algorithmic. In particular, for a quantum system in a quantum environment, when the former's quantum degrees of freedom are roughly uniformly partially decoherent, the Schrodinger wave equation cannot be propagated unitarily to preserve probability for all the quantum possibilities. While the Schrodinger equation for a fully coherent quantum system is lawful, we simply do not know if a quantum system losing phase information to its environment is describable by a law. If such a system is not describale by law, that constitutes a proof that such processes are real, and non-agorithmic, so not all that unfolds is algorithmic.
Having attempted again to counter the best present view of the mind as algorithmic, I now proceed to my own, radically different approach based on a quantum cohereing, decohering, recohering mind-brains system.
Let's look again at Cartesian dualism, Res Extensa and Res Cogitans. But Res Extensa according to DesCartes, Newton and classical physics is a deterministic dynamical system. Then the state of the brain - Res Extensa, is sufficient for the next state of the brain and there is nothing for mind to do. Worse, there is no way for Res Cogitans do do that something to the brain.
The situation is not helped by the mind-brain identity theory, for again philosophers do ask, and we can ask: If the brain-meat of the brain is a sufficient determinsitic condition for the next state of the brain, there is nothing for mind to do. Worse, the "mind" conscious part of the mind-brain system has no causal way to act on the brain!
Claims to stochastic equations for the dynamics of the brain will not help us, for these are merely "epistemological" stochastic events such as chaos when we cannot measure initial conditions accurately enough. The system is still deterministic ontologically.
But, critically, the above dilemma is purely stated in classical physics.
The world is not limited to classical physics, quantum mechanics also applies.
Now let me state again my hypothesis then defend it: The mind-brain system is quantum coherent, persistently decoheres to classicity and recoheres again to quantum coherent. The mind-brain system, since acausal decoherence takes an interval of time at least a femtosecond, can exist in a poised realm, see previous post, in which most or all its degrees of freedom are partially decoherent as it acausally loses phase information to the environment.
Then the mind does not act causally on the meat of the brain. Rather, the mind decoheres acausally to a classical "meat" brain state that has consequences for the classical aspects of the mind-brain system. Then mind can act on the brain, but does so acausally via decoherence.
Fine, I have suggested a solution to the problem of how mind can "act on" brain acausally. But the mind keeps acting on brain, so I am forced to assume that the classical, or classical (for all practical purposes - as some physicists say) brain can recohere partially or completely to the coherent quantum state.
In the remainder of this blog I will discuss evidence supporting decoherence and more tentative evidence supporting recoherence. In my next blog on a possible view of a responsible free will I will very tentatively identify the sites of such coherence, decoherence and recoherence as neurotransmitter molecules in synaptic vessicles, their post-synaptic receptors, and transmembrane channels in dendrites and possibly axons.
Decoherence is well extabished and is the bane of people trying to construct quantum computers. Different physicists differ on whether decoherence can proceed completely to classicity, or classicity "for all practical purposes", hence whether classical behavior always maintains some residue of quantum aspects.
Four lines of evidence support recoherence:
Shor's quantum error correction theorem establishes mathematically that injection of "information" about quantum phases (and amplitudes), can correct a quantum computer such that its quantum degrees of freedom return to coherence. This, of course, requires that the quantum system be distinguished from the quantum environment that supplies the phase and amplitude information, hence that the quantum system be "open".
Hans Briegel in the Physics Department at the University of Innsbruck, Austria, has published two theoretical papers claiming that a molecule can pass repeatedly from a quantum coherent "entangled" state to a classical state and back.
Recently, as noted by a commenter on my previous blog about a Poised Realm between quantum coherence and classical behavior, it has been proposed that a poised resonant state that is partially decoherent may account for high temperature superconducting.
Most striking, there is direct experimental evidence based on the familiar chlorophyll molecule, which carries out photosynthesis, and the "antenna" protein which is wrapped around the chlorophyll molecule. The normal time scale for decoherence is 10 to the- 15 seconds, a femtosecond. These workers have shown experimentally that coherence in chlorophyll at 77K, where K is Kelvin, absolute temperature and room temperature is 300K, can last at least as long as 7000 femtoseconds, or almost a nanosecond. This discovery is leading to a new field of quantum biology. Now it is thought that the antenna protein somehow "suppresses" decoherence. This is currently directly experimentally testable by using mutants of the antenna protein. But there is this further thought: chlorophyll, as a quantum system, is losing phase information to its environment. It is hard to imagine how the antenna protein can prevent this loss of phase information. Instead, it seems equally or more plausible that the antenna protein is acting, like Shor's quantum error correction algorithm above, to inject phase and amplitude information into chlorophyll. No one knows, so I will assume that the antenna protein injects phase and amplitude information into the chlorophyll molecule. Then it is hard to see how that injected information can exactly match the phase information chlorophyll is losing to the environment. If not, the temporal behavior of chlorophyll as a molecule in its envronment, in which many or all quantum degrees of freedom of chlorophyll are partly decoherent, cannot be described by the Schrodinger equation which is only able to unitarily propagates all the quantum possibilities together with all their phase and amplitude information. In short, chlorophyll is likely to be an open system gaining and losing phase and amplitude information all the time from and to its environment, and therefore it is not clear that a law describes its behavior. In particular, we do not know how that phase information is being lost to the environment, either in general, or due to Popper's argument in a Special Relativity setting as described in a previous blog.
In summary, it is plausible that both quantum decoherence and recoherence partially or totally to a quantum coherent state can happen, perhaps lawlessly from a quantum system to its environment - the universe.
Then my proposal is that the mind-brain system is such a quantum coherent, decohering to classicity, perhaps for all practical purposes, and recohering system, in which mind has acausal consequences for classical brain matter without acting causally on brain matter.
How mind acts on matter has a proposed answer.