The quantum mind or quantum consciousness hypothesis proposes that classical mechanics cannot explain consciousness. It posits that quantum mechanical phenomena, such as quantum entanglement and superposition, may play an important part in the brain's function and could form the basis of an explanation of consciousness. It is not a single theory, but rather a collection of hypotheses.
A few theoretical physicists have argued classical physics is intrinsically incapable of explaining the holistic aspects of consciousness, whereas quantum mechanics can. The idea that quantum theory has something to do with the workings of the mind go back to Eugene Wigner. He assumed the wave function collapses due to its interaction with consciousness. Physicist Freeman Dyson argued that "mind, as manifested by the capacity to make choices, is to some extent inherent in every electron." However, most contemporary physicists and philosophers consider these arguments to be unconvincing. Physicist Victor Stenger characterized quantum consciousness as a "myth" having "no scientific basis" that "should take its place along with gods, unicorns and dragons."
The philosopher David Chalmers has argued against quantum consciousness. He has instead discussed how quantum mechanics may relate to dualistic consciousness. Chalmers is skeptical of the ability of any new physics to resolve the hard problem of consciousness.
Description of main quantum mind approaches
David Bohm viewed quantum theory and relativity contradict one another. The contradiction implied there existed a more fundamental level in the physical universe. He claimed both quantum theory and relativity pointed towards this deeper theory, which he formulated in terms of a quantum field theory. This more fundamental level was proposed to represent an undivided wholeness and an implicate order, from which arises the explicate order of the universe as we experience it.
Bohm proposed implicate order applies both to matter and consciousness and suggested it could explain the relationship between them. Mind and matter are seen as projections into our explicate order from the underlying reality of the implicate order. Bohm claims that when we look at the matter in space, we can see nothing in these concepts that helps us to understand consciousness.
In trying to describe the nature of consciousness, Bohm discussed the experience of listening to music. He believed the feeling of movement and change that make up our experience of music derives from both the immediate past and the present both being held in the brain together. The notes from the past are seen as transformations rather than memories. The notes that were implicate in the immediate past are seen as becoming explicate in the present. Bohm viewed this as consciousness emerging from the implicate order.
Bohm saw the movement, change or flow, and the coherence of experiences, such as listening to music, as a manifestation of the implicate order. He claimed to derive evidence for this from the work of Jean Piaget in studying infants. He stated these studies show that young children have to learn about time and space not because they are part of the explicate order; rather, they have a "hard-wired" understanding of movement because it is part of the implicate order. He compared this "hard-wiring" to Chomsky's theory that grammar is "hard-wired" into young human brains.
A major weakness to Bohm's hypothesis is verification. In his writings, Bohm never proposed any specific means by which the propositions could be tested or falsified, nor a neural mechanism through which his "implicate order" could emerge in a way relevant to consciousness. Bohm did, however, collaborate on Karl Pribram's holonomic brain theory as a model of quantum consciousness.
Roger Penrose and Stuart Hameroff
Theoretical physicist Roger Penrose and anaesthesiologist Stuart Hameroff collaborated to produce the theory known as Orchestrated Objective Reduction (Orch-OR). Penrose and Hameroff initially developed their ideas separately and only later collaborated to produce Orch-OR in the early 1990s. The theory was reviewed and updated by the original authors in late 2013.
Penrose's controversial argument stemmed from Gödel's incompleteness theorems. In Penrose's first book on consciousness, The Emperor's New Mind (1989), he argued that while a formal proof system cannot prove its own inconsistency, Gödel unprovable results are provable by human mathematicians. In the book, he took this disparity to mean that human mathematicians are not describable as formal proof systems and are not running a computable algorithm. This line of reasoning is based on fallacious equivocation on the meaning of computation.
Penrose determined wave function collapse was the only possible physical basis for a non-computable process. Dissatisfied with its randomness, Penrose proposed a new form of wave function collapse that occurred in isolation and called it objective reduction. He suggested each quantum superposition has its own piece of spacetime curvature and when these become separated by more than one Planck length they become unstable and collapse. Penrose suggested that objective reduction represented neither randomness nor algorithmic processing but instead a non-computable influence in spacetime geometry from which mathematical understanding and, by later extension, consciousness derived.
Originally, Penrose lacked a detailed proposal for how quantum processing could be implemented in the brain. However, Hameroff read Penrose's work and suggested that microtubules would be suitable candidates. Microtubules are composed of tubulin protein dimer subunits. The tubulin dimers each have hydrophobic pockets that are 8 nm apart and which may contain delocalized pi electrons. Tubulins have other smaller non-polar regions that contain pi electron-rich indole rings separated by only about 2 nm. Hameroff proposed that these electrons are close enough to become quantum entangled. Hameroff originally suggested the tubulin-subunit electrons would form a Bose–Einstein condensate, but this was discredited. He then proposed a Frohlich condensate, a hypothetical coherent oscillation of dipolar molecules. However, this too has been experimentally discredited.
Furthermore, he proposed that condensates in one neuron could extend to many others via gap junctions between neurons forming a macroscopic quantum feature across an extended area of the brain. When the wave function of this extended condensate collapsed, it was suggested to non-computationally access mathematical understanding and ultimately conscious experience which are hypothetically embedded in the geometry of spacetime.
However, Orch-OR made numerous false biological predictions, and is considered to be an extremely poor model of brain physiology. The proposed predominance of 'A' lattice microtubules, more suitable for information processing, was falsified by Kikkawa et al., who showed all in vivo microtubules have a 'B' lattice and a seam. The proposed existence of gap junctions between neurons and glial cells was also falsified. Orch-OR predicted that microtubule coherence reaches the synapses via dendritic lamellar bodies (DLBs), however De Zeeuw et al. proved this impossible, by showing that DLBs are located micrometers away from gap junctions.
In January 2014, Hameroff and Penrose announced the discovery of quantum vibrations in microtubules by Anirban Bandyopadhyay of the National Institute for Materials Science in Japan in March 2013 confirms the hypothesis of the Orch-OR theory.
In early 2015 it was revealed that pulsed transcranial ultrasound seems to improve memory functioning in Alzheimer's mice as well as helping to break down amyloid plaques.  This could still be relevant to Orch-OR as originally theorized by the page authors ultrasound is actually just activating latent brain repair and cleanup mechanisms; if it was also helping to boost the disease weakened cemi field within the neurons directly in a similar way to adding noise to a signal sometimes boosts it above the noise floor then a similar high frequency ultrasound transmitter tuned to the specific microtubule vibrations could work even in a PVS patient.
Umezawa, Vitiello, Freeman
Hiroomi Umezawa and collaborators proposed a quantum field theory of memory storage. Giuseppe Vitiello and Walter Freeman have proposed a dialog model of the mind. This dialog takes place between the classical and the quantum parts of the brain. Their quantum field theory models of brain dynamics are fundamentally different from the Penrose-Hameroff theory.
Karl Pribram's holonomic brain theory (quantum holography) invoked quantum mechanics to explain higher order processing by the mind. He argued the holonomic model solved the binding problem. Pribram collaborated with Bohm in his work on the quantum approaches to mind and he provided evidence on how much of the processing in the brain was done in wholes. He proposed that ordered water at dendritic membrane surfaces might operate by structuring Einstein-Bore condensation supporting quantum dynamics.
Although Subhash Kak's work is not directly related to that of Pribram, he likewise proposes the physical substratum to neural networks has a quantum basis, but he asserts that the quantum mind will still have machine-like limitations. He points to a role for quantum theory in the distinction between machine intelligence and biological intelligence, but that in itself cannot explain all aspects of consciousness.
Henry Stapp favors the idea that quantum waves are reduced only when they interact with consciousness. He argues from the Orthodox Quantum Mechanics of John von Neumann that the quantum state collapses when the observer selects one among the alternative quantum possibilities as a basis for future action. The collapse, therefore, takes place in the expectation that the observer associated with the state. Stapp's work has drawn criticism from scientists such as David Bourget and Danko Georgiev. Recent papers by Georgiev criticize Stapp's model in two aspects: (1) The mind in Stapp's model does not have its own wavefunction or density matrix, but nevertheless can act upon the brain using projection operators. Such usage is not compatible with standard quantum mechanics because one can attach any number of ghostly minds to any point in space that act upon physical quantum systems with any projection operators. Therefore Stapp's model does not build upon "the prevailing principles of physics", but negates them. (2) Stapp's claim that quantum Zeno effect is robust against environmental decoherence directly contradicts a basic theorem in quantum information theory according to which acting with projection operators upon the density matrix of a quantum system can never decrease the Von Neumann entropy of the system, but can only increase it.
Criticism by Max Tegmark
The main argument against the quantum mind proposition is that quantum states in the brain would decohere before they reached a spatial or temporal scale at which they could be useful for neural processing, although in photosynthetic organisms quantum coherence is involved in the efficient transfer of energy, within the timescales calculated by Quantum biology. This argument was elaborated by the physicist, Max Tegmark. Based on his calculations, Tegmark concluded that quantum systems in the brain decohere at sub-picosecond timescales commonly assumed to be too short to control brain function.
- Bohm interpretation of quantum mechanics
- Electromagnetic theories of consciousness
- Evolutionary neuroscience
- Hameroff-Penrose Orchestrated Objective Reduction
- Hard problem of consciousness
- Holonomic brain theory
- Mechanism (philosophy)
- Quantum cognition
- Theory of mind
- "Quantum Approaches to Consciousness". Stanford Encyclopedia of Philosophy. First published Tue Nov 30, 2004; substantive revision Thu May 19, 2011. Check date values in:
- Dyson, Freeman (2004). Infinite in All Directions: Gifford Lectures Given at Aberdeen, Scotland April--November 1985 (1st Perennial ed.). New York: Perennial. p. 297. ISBN 0060728892.
- Searle, John R. (1997). The Mystery of Consciousness (1. ed. ed.). New York: New York Review of Books. pp. 53–88. ISBN 9780940322066.
- Stenger, Victor. The Myth of Quantum Consciousness (PDF). The Humanist. 53 No 3 (May–June 1992). pp. 13–15.
- Stich, Stephen P.; Warfield, Ted A. (2003). The Blackwell Guide to Philosophy of Mind. Malden, MA: Blackwell Pub. ISBN 9780470998755.
- David J. Chalmers (1995). "Facing Up to the Problem of Consciousness". Journal of Consciousness Studies 2 (3): 200–219.
- Chalmers, David J. (1997). The Conscious Mind: In Search of a Fundamental Theory (Paperback ed. ed.). New York: Oxford University Press. ISBN 978-0-19-511789-9.
- Bohm, David (2002). Wholeness and the Implicate Order. (Online-Ausg. ed.). Hoboken: Routledge. ISBN 0203995155.
- Piaget, Jean (1997). Jean Piaget: selected works. (The Origin of Intelligence in the Child) (Repr. ed.). London: Routledge. ISBN 9780415168861.
- Wade, Jenny (1996). Changes of Mind: A Holonomic Theory of the Evolution of Consciousness. Albany: State Univ. of New York Press. ISBN 9780791428498.
- unattributed (2014-01-16). "Discovery of Quantum Vibrations in...". sciencedaily.com. Retrieved 2014-01-16.
- "Discovery of Quantum Vibrations in "Microtubules" Inside Brain Neurons Corroborates Controversial 20-Year-Old Theory of Consciousness". Elsevier. Retrieved 2014-08-04.
- Gödel, Kurt (1992). On Formally Undecidable Propositions of Principia Mathematica and Related Systems (Reprint. ed.). New York: Dover Publications. ISBN 0486669807.
- Bringsjord, S. and Xiao, H. 2000. A Refutation of Penrose's Gödelian Case Against Artificial Intelligence. Journal of Experimental and Theoretical Artificial Intelligence
- Penrose, Roger (1999). The Emperor's New Mind: Concerning Computers, Minds, and the Laws of Physics ([New edition] ed.). Oxford: Oxford Univ. Press. ISBN 0192861980.
- Penrose, Roger (1995). Shadows of the Mind: A Search for the Missing Science of Consciousness (Repr. (with corrections). ed.). Oxford [u.a.]: Oxford Univ. Press. ISBN 0198539789.
- Hameroff, Stuart (2008). "That's life! The geometry of π electron resonance clouds". In Abbott, D; Davies, P; Pati, A. Quantum aspects of life (PDF). World Scientific. pp. 403–434. Retrieved Jan 21, 2010.
- Roger Penrose & Stuart Hameroff (2011). "Consciousness in the Universe: Neuroscience, Quantum Space-Time Geometry and Orch OR Theory". Journal of Cosmology 14.
- Reimers, Jeffrey R.; McKemmish, Laura K.; McKenzie, Ross H.; Mark, Alan E.; Hush, Noel S. (17 March 2009). "Weak, strong, and coherent regimes of Fröhlich condensation and their applications to terahertz medicine and quantum consciousness". PNAS 106 (11): 4219–4224. Bibcode:2009PNAS..106.4219R. doi:10.1073/pnas.0806273106. PMC 2657444. PMID 19251667. Retrieved 10 June 2013.
- Kikkawa, M., Ishikawa, T., Nakata, T., Wakabayashi, T., Hirokawa, N. (1994). "Direct visualization of the microtubule lattice seam both in vitro and in vivo". Journal of Cell Biology 127 (6): 1965–1971. doi:10.1083/jcb.127.6.1965. PMC 2120284. PMID 7806574.
- Kikkawa, M., Metlagel, Z. (2006). "A molecular "zipper" for microtubules". Cell 127 (7): 1302–1304. doi:10.1016/j.cell.2006.12.009. PMID 17190594.
- F. J. Binmöller & C. M. Müller (1992). "Postnatal development of dye-coupling among astrocytes in rat visual cortex". Glia 6 (2): 127–137. doi:10.1002/glia.440060207. PMID 1328051.
- De Zeeuw, C.I., Hertzberg, E.L., Mugnaini, E. (1995). "The dendritic lamellar body: A new neuronal organelle putatively associated with dendrodentritic gap junctions". Journal of Neuroscience 15 (2): 1587–1604. PMID 7869120.
- "Consciousness, the brain, and spacetime geo... [Ann N Y Acad Sci. 2001] - PubMed - NCBI". Ncbi.nlm.nih.gov. 2013-08-12. Retrieved 2014-01-16.
- "Atomic water channel controlling remarka... [Biosens Bioelectron. 2013] - PubMed - NCBI". Ncbi.nlm.nih.gov. 2014-05-14. Retrieved 2014-07-30.
- Osborne, Hannah (2014-01-16). "Quantum Vibrations in Brain Opens 'Pandora's Box' of Theories of Consciousness - Yahoo News UK". Uk.news.yahoo.com. Retrieved 2014-08-04.
- "Ultrasound 'breakthrough' in treating Alzheimer's - in mice - Health News - NHS Choices". Nhs.uk. 2015-03-12. Retrieved 2015-03-31.
- G. Vitiello, My Double Unveiled. John Benjamins, 2001.
- Freeman, W. and G. Vitiello, Nonlinear brain dynamics as macroscopic manifestation of underlying many-body dynamics. Physics of Life Reviews, vol. 3, pp 93-118, 2006.
- Pribram, K. H. (1999). Quantum holography: Is it relevant to brain function? Information Sciences, 115(1–4), 97–102.
- Pribram, K.H. (2004). Consciousness Reassessed. Mind and Matter, 2, 7–35.
- Pribram, K. (1999) Status Report: Quantum Holography and the Braln. Acta Polyiechnica Scandinavica: Emergence Complexity, Hierarchy, Organization, Vol. 2, pp. 33-60.
- Pribram, K.H. Holography, holonomy and brain function. Elsevier's Encyclopedia of Neuroscience, 1999.
- Jibu, M., Pribrm, K. H., & Yasue, K. (1996). From conscious experience to memory storage and retrieval: The role of quantum brain dynamics and boson condensation of evanescent photons. International Journal of Modern Physics B, 10, 1735-1754.
- Kak, S. (1995) Quantum neural computing, In Advances in Imaging and Electron Physics, vol. 94, P. Hawkes (editor). Academic Press, 259-313.
- Kak, S. (1996) The three languages of the brain: quantum, reorganizational, and associative. In Learning as Self- Organization, K. Pribram and J. King (editors). Lawrence Erlbaum Associates, Mahwah, NJ, 185-219.
- Gautam, A. and S. Kak (2013), Symbols, meaning, and origins of mind. Biosemiotics (Springer Verlag) 6: 301-310.
- Kak, S. (2000), Active agents, intelligence, and quantum computing. Information Sciences 128: 1-17.
- Kak, S. (2005), Artificial and biological intelligence. ACM Ubiquity 6 (42): 1-22.
- Bourget, D. (2004). "Quantum Leaps in Philosophy of Mind: A Critique of Stapp's Theory". Journal of Consciousness Studies 11 (12): 17–42.
- Georgiev, D. (2012). "Mind efforts, quantum Zeno effect and environmental decoherence". NeuroQuantology 10 (3): 374–388. doi:10.14704/nq.2012.10.3.552.
- Georgiev, D. (2015). "Monte Carlo simulation of quantum Zeno effect in the brain". International Journal of Modern Physics B 29 (7): 1550039. arXiv:1412.4741. doi:10.1142/S0217979215500393.
- Engel, G. (2007). "Evidence for wavelike energy transfer through quantum coherence in photosynthetic systems". Nature 446 (7137): 782–786. doi:10.1038/nature05678. PMID 17429397.
- Tegmark, M. (2000). "Importance of quantum decoherence in brain processes". Physical Review E 61 (4): 4194–4206. arXiv:quant-ph/9907009. Bibcode:2000PhRvE..61.4194T. doi:10.1103/PhysRevE.61.4194.
- Charles Seife (4 February 2000). "Cold Numbers Unmake the Quantum Mind". Science 287 (5454): 791. doi:10.1126/science.287.5454.791. PMID 10691548.
- Flanagan, Brian. Are Perceptual Fields Quantum Fields?
- Hodgson, David. The Mind Matters. Oxford University Press, 1993.
- Koch, C. and Hepp, K., "Quantum mechanics in the brain", Nature 440, 611 (30 March 2006)
- Litt et al., "Is the Brain a Quantum Computer?", Cognitive Science (2006)
- Lockwood, Michael. Mind, Brain and the Quantum. Cambridge, Massachusetts: Basil Blackwell Ltd., 1989.
- McFadden, Johnjoe (2000) Quantum Evolution HarperCollins. ISBN 0-00-255948-X; ISBN 0-00-655128-9 . Final chapter on the quantum mind.
- Pharaoh, M.C. (online). Looking to quantum mechanics for a reductive explanation of the noumenon of consciousness Retrieved June.21 2008.
- Schrödinger, Erwin. Mind and Matter. Cambridge University Press, 1959.
- Weyl, Hermann. Mind and Nature, University of Pennsylvania Press, 1934.
- Wigner, Eugene. "Physics and the Explanation of Life", in Foundations of Physics, vol. 1, 1970, pp. 34–45.
- Center for Consciousness Studies, directed by Stuart Hameroff
- Online papers on consciousness
- Stanford Univ. Encyclopedia of Philosophy critical survey article Harald Altmanspacher (2006) Quantum Approaches to Consciousness
- "What is an Essentially Quantum Mechanical Effect?", Osvaldo Pessoa Jr.