Quantum Consciousness, Quantum Information, and Subjectivity
What is consciousness? This question, a toughie it is. --Dr. Yodapappankin
Chikarawa Shiyookudasai, professor emeritus, Kashyyyk University
Introduction
In the past century, physics and physics-driven philosophy have moved toward greater abstraction and away from absolutes. The Heisenberg interpretation of quantum mechanics, for example, views such questions as whether wave-particle duality is "real" as meaningless. In this view, the only value of such concepts is whether they accurately predict phenomena at the atomic level. Indeed, onn this small scale, our everyday experience about what constitutes a particle or a wave misleads us. For example, it is very difficult to visualize how an electron can be both a particle and a wave. Yet the experimental evidence tells us that it is. In fact, at this scale, all objects, including neutrons, photons, electrons, and even alpha particles, are both particles and waves. Nature doesn't care if we find the concept difficult to grasp.
Recently, it has become clear that we must face the possibility that information, as well, deserves a place at the quantum table. In return, nature may have given us a clue about how to understand a question that has baffled philosophers for millenia: what is consciousness.
That this question is difficult to answer can be seen by the number
of attempts that have failed, not because they did not arrive at a
solution, but because they could not even ask the right question.
Many philosophers have found themselves bogged down in trying to
account for psychological or biological phenomena, such as
figure-ground illusions, qualia, and anesthesia. In so doing, they
have almost invariably strayed off the topic and answered some other
question that is not, in fact, related to the philosophical concept
of consciousness.
What do we mean by "consciousness"?
Therefore, it is worth taking a few moments to define what we mean and more importantly, what we do not mean by "consciousness". In this article, consciousness is that quality that distinguishes the "self" from "everybody else". Consciousness, in this context, could also be called "subjectivity". Understanding the question of "what is consciousness" would give us an answer to the question, "Why am I me and not somebody else?"
At first glance, this question may sound trivial: you are you because you are over there--yes, you--the one sitting in that chair eating Cheese Puffs, or donuts, or whatever those things are--and everyone else is somewhere else. But on a more fundamental level, the question is quite difficult to answer. Every individual is well aware of their own subjectivity. We all have a sense of self that seems to extend to the limits of what we can directly sense and touch. If our brains were connected together, we intuitively feel that our sense of self would include other people as well. So it is clear that information is part of what constitutes our subjectivity. But even if our sensory apparatus could receive information from and we could affect every object in the universe, there would still be a distinction between self and non-self. The distinction is an inherent property of information, and the direction in which information flows.
Some aspects of our concept of self are undoubtedly an illusion. We evolved to think of ourselves as individuals who must maintain a coherent identity in order to survive and interact with other individuals in society. But this does not change the fact that there is a fundamental distinction between self and non-self. From the point of view of a self, information flows toward and away from it. One could even say that 'having a point of view' bestows selfness. In contrast, among non-selfs or "others", information is external. It flows from one point to another, but we are not "inside" the information. This quality of being inside the information cannot be flippantly dismissed as an illusion without ignoring a fundamental fact about our reality.
What this all means is that subjectivity may be the last vestige
of an absolute point of view in science. Einstein's theory of
relativity has effectively eliminated the concept of an absolute
rest frame. Even time does not have a unique frame of reference.
So it is not surprising that some scientists have adopted the
more reductionistic approach and are seemingly obsessed with attempts
to eliminate the absolute point of view in consciousness. Unfortunately,
this may not be possible: the absolute point of view is precisely
what defines consciousness.
What is not meant by "consciousness"?
The field of "consciousness studies" has also become confused by the fact that many scientists, discussing "consciousness" from different angles, are really talking about other topics. For instance, if we talk about figure-ground illusions such as the image below, and ask what happens when we perceive a vase instead of two faces, we are actually discussing perception, not consciousness. Even though we are obviously conscious of some change when our perception changes, explaining the figure-ground illusion is unlikely to shed light on the bigger question of what consciousness actually is. The figure-ground illusion is, rather, a question of "how the brain works" and much progress has been made in the field of neuroscience in answering this question. As interesting as that question may be, it is outside the scope of this article.
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| Figure-ground illusion | Blueness |
| Figure 1 |
Similarly, when we talk about "qualia", a term that refers to our sensation of "warmth", or "pain", or "blueness" for the image above, we are really again discussing perceptual issues and not consciousness per se. The psychological value of "blueness" is created by the ocean of associations, along with various learned cultural associations that we have acquired concerning things that are blue. The ability to appreciate blueness does not change much when it is some other person who is perceiving it, and hence it does little to help us understand the differences in information flow under the conditions of subject and object--which is really what we're concerned about in this article.
Another usage of the term "consciousness", distinct from that used here, is found in anesthesiology. Some research suggests that volatile anesthetics such as halothane may interact with microtubules in neurons [4,5,6] (see Hamerhof's summary at http://listserv.uh.edu/cgi-bin/wa?A2=ind9708&L=psyche-b&P=830). This connection between microtubules and anesthesia may have been one reason why Penrose and Hameroff picked tubulin out of the 15,000 or so proteins in the neuron to serve as detectors for superposed quantum events [1]. They proposed that proteins comprising the neuronal cytoskeleton can somehow "tune" the quantum oscillations of the coherent superposed states. They propose that microtubules are somehow able to avoid environmental decoherence long enough to act as transducers for quantum phenomena [2]. This theory has been criticized on physical grounds [3] and it's probably fair to say that getting biochemists to accept this theory will be an uphill battle.
Quantum decoherence
Nonetheless, it is important to understand just how Penrose and others believe that detecting superposed quantum states relates to consciousness. Quantum mechanics enters into the question of consciousness because the simplest interpretation of the experimental results about photons is that their state, whether it is polarization (vertical or horizontal) or, in the case of a cat, alive or dead, is not determined until they are measured or "observed." The particle's condition is not simply unknown; both states coexist and are superposed. When the particle interacts with something, it can only do so as one state or the other, so it is forced to randomly fall into one or the other state. This causes "decoherence", or loss of its unrealized potentiality. Schrödinger used cats as an example, not just because of his warped sense of humor, but to emphasize the strangeness of what he was saying.
Superposed states are not just theoretical entities. The entire field of quantum computation is based on the idea that quantum particles in their superposed state, possess a huge amount of information.
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| Role of the observer in quantum decoherence. The act of measurement forces the wavefunction to "collapse", or adopt one state, because only one physical outcome is possible. Pretend that these are cats. |
| Figure 2 |
Perhaps, we may discover that some other protein instead of tubulin, like keratin (which is at least closer than tubulin to the surface) or glyceraldehyde 3-phosphate dehydrogenase, may be the quantum detector. H.S. Green, for example, proposed that calcium channels, not microtubules, were the generators of consciousness [7]. Stapp argues along similar lines, reasoning that an external quantum event could "actualize the entire large-scale integrated pattern of neural excitations associated with the metastable state of the brain that goes along with a particular conscious thought." [8]
Note that we have two diametrically opposite points of view here: Penrose takes a more conservative position, saying that an individual microtubule undergoes some conformational change which decoheres a superposed state. Stapp takes a much more radical view, saying that the entire brain performs a quantum measurement and somehow adopts its overall configuration in response to a single quantum measurement. The question is, is such a thing possible, and how could this produce consciousness?
In his book, Mind, Matter, and Quantum Mechanics, Stapp describes his ideas about the structure of the human brain that could, in his opinion, allow it to serve as a quantum de-tangler. He writes:
...[Q]uantum theory generates in the conscious brain a superposition of many different mutually exclusive self-sustaining patterns with different statistical weights. The image in physical theory of the conscious act is the act of selecting one of these patterns.
This idea that ideas float around in the brain as discrete entities, and are selected and pitted against each other is somewhat reminiscent of the neural network models of Hopfield and his many followers. Hopfield networks consist of a large completely- or almost completely-interconnected network of neurons with little or no large-scale structure. Hopfield networks were very popular among physicists and mathematicians at one time because of their mathematical simplicity. Stapp's idea, as I understand it, is that Hopfield patterns correspond to entangled, superposed quanta, and the brain's function is to select patterns. This, says Stapp, is consciousness.
The concept of patterns being existing as discrete entities, and being selected on the basis of their "fitness" for describing the outside world is also reminiscent of Edelman's neural darwinism, which he described in his book Neural Darwinism: The Theory of Neuronal Group Selection. Edelman has also written extensively about his theories of consciousness. His central hypothesis is
.. a group of neurons can contribute directly to conscious experience if it is part of a functional cluster, characterized by strong mutual interactions among a set of neuronal groups over a period of hundreds of milliseconds.
From the foregoing it should be clear that both Stapp and Edelman are
discussing a different aspect of consciousness from what is being
discussed here. For both Stapp and Edelman, "consciousness" refers to
the mechanics of cognitive activity in the brain. To me, it seems that,
as important as the brain is for consciousness, the brain is only the
tool that allows us to experience consciousness. Whatever the biological
mechanism by which the brain recognizes patterns and constructs its own
internal representation of reality, there is an additional step that is
necessary to describe human consciousness. What is it that allows
consciousness, uniquely in all the aspects of nature studied so far,
to create a preferred reference point? Why does the universe appear
to be focused at one point for one individual and at another point
for another individual? This is what Kant called "immanence", and
attempts to explain it philosophically have led to dualism (a concept
that seems to be widely misunderstood by many scientist-philosophers).
Despite Herculean efforts, no amount of reductionism has so far been
able to explain away the reality of our everyday lives that is
subjectivity.
Problems with quantum consciousness
The first problem with quantum consciousness has been extensively discussed, by Tegmark and others: a tubulin molecule interacts with its environment continuously, and thus its state is constantly being "observed" at a rate far too high to make it useful as a quantum detector. A related problem is that tubulin molecules are buried deep inside the brain. It's virtually impossible for photons or any other particles to reach a tubulin molecule without interacting with something else, and thereby losing its coherence. Stapp's solution, taking the entire brain as a quantum detector, does not really solve the problem, unless one takes the view that we are not dealing with particles, but large-scale pieces of information. If information itself can be coherent, then such a thing might be possible.
The second problem is more fundamental: even if we grant that the brain can act as a quantum detector, just how does this create consciousness? The brain processes ordinary photons and information all the time. What is different about quantum information?
The answer is that detecting a bit of quantum information changes the environment. As in the Schroedinger cat experiment (Fig.2), an observer measuring whether the cat is alive or dead causes the cat to be either alive or dead. We could generate two entangled photons. If the observer observes the state of one photon, assuming that Penrose et al. are right, the state of the other becomes known. If Penrose was right, we could use this to determine empirically whether ants, computer programs, or clouds have consciousness.
One potential difficulty is that, at some point in the experiment, the experimenter must observe the data. A few physicists have suggested that this is the point at which the wavefunction collapses. If so, the experiment would only tell us what we already know: that the experimenter is conscious. Moreover, the theory depends on whether consciousness is actually required to cause decoherence. If it is not, the entire edifice of quantum consciousness would collapse.
An even more serious problem is the cosmological implications. If we were to accept that measurement requires a conscious being, as proponents of quantum consciousness suggest, it has uncomfortable implications about the universe as a whole. Clearly, no one could ever have observed every star, inside and out. If observing something is necessary for it to exist, we would either have to posit some supernatural being who observes the creation of every atom, or accept as a fact that the universe does not, in fact, really exist, except for the part that we can see.
Even if this problem could be swept under the rug, the main question is still left unanswered. How does a wavefunction collapse produce consciousness? Penrose, in his book The Emperor's New Mind and elsewhere, has speculated about perturbations of spacetime geometry, spin networks, and even gravity. Penrose insightfully recognized that an explanation of time is also needed to understand consciousness. He wrote:
The self-collapse [of the wave function], irreversible in time, creates an instantaneous `now' event. Sequences of such events create a flow of time, and consciousness.
This is all very interesting, and it has a great Star Trekky feel about
it, but it's not a compelling explanation of consciousness. Just what is
a "now event" exactly, and just how does a flow of time create
consciousness? More fundamentally, why do Stapp and Penrose believe that
a conscious observer is necessary to produce a wavefunction collapse?
Both physicists take this point as axiomatic, and it is essential for
their theories. Therefore, we need to take a detour and discuss the
famous two-slit experiment.
The Famous Two-Slit Experiment
To be finished soon
What is Consciousness
Here is the answer to the question, "What is consciousness?": ... Oh darn, the funding just ran out
To be finished soon
Conclusion
References
- Ann N Y Acad Sci. 2001 Apr;929:74-104. Consciousness, the brain, and spacetime geometry. Hameroff S.
- Phys Rev E Stat Nonlin Soft Matter Phys. 2002 Jun;65(6 Pt 1). Quantum computation in brain microtubules: decoherence and biological feasibility. Hagan S, Hameroff SR, Tuszynski JA.
- Tegmark
- Allison, A.C, Hulands, G.H., Nunn, J.F., Kitching, J.A., and MacDonald A.C. (1970) The effects of inhalational anaesthetics on the microtubular system in Actinosphaerium nucleofilm. J. Cell Science 7:483-499
- Allison, A.C., and Nunn, JF. (1968) Effects of general anesthetics on microtubules. A possible mechanism of anesthesia. Lancet 2:1326-1329
- Vergara GA, Livingston A (1981) Halothane modifies colchicine binding to tubulin. Pharmacology 23(5):264-270
- Green
- Stapp p 44
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