Saturday, March 12, 2011

How Mind Can Act causally On Brain?


In this blog I want to turn to the problem we have had since Rene Descartes proposed his dualism: Res Cogitans and Res Extensa. Here Res Extensa captures his mechanistic world view in which our bodies, like clocks, are deterministic machines. Res Cogitans is our “mind” as “thinking stuff.”

With Newton’s deterministic classical physics, Res Extensa ruled, and Res Cogitans become deeply problematical.
Why? Because the question arose, “How does mind act causally on brain?”

Here is the essence of the issue: Consider Newtonian billiard balls released on a table, where the initial positions and momenta of the balls, and the boundary conditions of the table, plus Newton’s laws of motion in differential form, yield, upon integration of those equations, the future sequence of positions and momenta of the balls deterministically for all time.
If the brain is a deterministic classical physical system like the billiard balls, then the current state of the brain is entirely sufficient to determine — cause — the next state of the brain. Thus, there is nothing for the the mind to do. More there is no way for the mind to do "it."  What is consciousness supposed to do? Interfere with and alter the classical, deterministic, dynamical processes of the brain in some magical way?
That, in a nutshell, is the problem with Descartes’ dualism.
  A current version of this issue is the belief among many that the brain is like a vast network of interconnected logical electronic switches. At some level of complexity consciousness will arise. A parallel is often drawn to the fact that a single water molecule is not wet, but a sufficiently large set of water molecules can be wet. At a sufficient complexity of logical switches, a new property emerges and is associated with consciousness. The hope is that this new property that emerges, but is not yet consciousness itself, can act causally on the brain.
This view may be correct.  Some have proposed that the electromagnetic field of the brain is that emergent property.
Note that were this view correct, then all of this still remains causally deterministic in the behavior of the mind-brain system. The brain is sufficient for the next state of the brain, so there is nothing for mind to do and no way for mind to do it.  Thus this consciousness seems to be a mere epiphenomenon, causally useless, and because the total system is deterministic, it leaves no room for an ontologically real and responsible free will.
(See Dennett’s Freedom Evolves for a careful view that accepts determinism and proposes to build a sense of a free will.)
I want to explore a different set of ideas, based on the new physics of open quantum systems, the Poised Realm, and Trans-Turing Systems of previous posts.
As I have discussed in the posts about open quantum systems and the Poised Realm, it is well known that loss of phase information from the open quantum system to its quantum environment, called “decoherence”, is both well established experimentally, causes the famous two slit interference light dark band pattern to disappear, and is now one of the favored hypothesis about the transition from the open quantum world to the classical world, at least “for all practical purposes”, FAPP.
Less well known, is that there is growing evidence that the decoherence process can be reversed.  A decoherent system can be made open quantum coherent again, a process I will call “Recoherence.” For example, the Shor quantum computer error correction theorem shows that injection of information can make decohering qubits recohere. A number of workers are finding evidence for recoherence, (see Electromagnetically Induced Quantum Memory” by A. Nazarkin et.al. Phys. Rev. Lett., 2004.) The quantum coherence in chlorophyll wrapped by its antenna protein may be an experimental example.
It is essential that decoherence is NOT a causal process. It is the acausal loss of phase information from an open quantum system to its environment such that the open quantum system then becomes classical FAPP.
Then how might mind act acausally on matter? Mind might act acausally via decoherence from open quantum to classical FAPP behavior.
If so we may have just begun to escape the the issue since Descartes. Mind, if open quantum and/or poised realm, can have ACAUSAL CONSEQUENCES for brain. Mind on this view does NOT ACT CAUSALLY ON BRAIN.
But this will not help if can only happen once in your lifetime. Then let’s suppose that even after decoherence to classicality FAPP where mind has acted acausally on brain, the total mind-brain system can have some degrees of freedom which recohere to open quantum coherent behavior and can decohere again and cycle over and over. Then your open quantum and/or poised realm mind can have acausal consequences for your classical FAPP brain throughout your lifetime.
If this is correct, it could solve the Cartesian dualism problem of how the mind can act on the brain.
If we can find the brain loci of such decoherence and recoherence as part of the emerging field of quantum biology, we may find experimental evidence for this hypothesis.
The physically realizable system that may be the natural “home” for this process is the Trans-Turing System, discussed a few posts ago, one or a set of them communicating with one another, that cycle repeatedly between open quantum, poised realm, and classical FAPP behavior.  Thus it becomes a scientific hypothesis that your mind-brain system is a set of one or trillions of interacting Trans-Turing Systems. In a later post, I’ll suggest that these correspond to neurotransmitter receptors in post synaptic membranes, with testable consequences.
Trans Turing systems are not algorithmic because they inherit the indeterminacy of quantum mechanics, thus are not definite. Algorithms, such as the Turing machine which is the basis of all digital computers, are completely definite. Turing machines are the perfect realization of Descartes’ Res Extensa and are purely classical physical systems.  Thus, Trans-Turing Systems which are not definite are NOT algorithmic systems, yet process information. Therefore, contrary to the common belief, the mind-brain system need not be algorithmic. We need not be classical computing networks straining to pass the  famousTuring Test. I emphasize that I am making a scientific hypothesis open to experimental tests.
In future blogs, I will discuss hypotheses about what consciousness “IS”, about the brain loci of our consciousness, what qualia “are”, the “unity of consciousness” and try to develop ideas for an ontologically real free will where we humans do really act as agents.
Of course, I cannot know this set of ideas is correct. Yet there are testable consequences and this is a potentially new view of our humanity.

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