Activitas Nervosa Superior

, Volume 61, Issue 1–2, pp 31–40 | Cite as

Consciousness and Quantum State Reduction—Which Comes First?

  • Stuart HameroffEmail author


Consciousness and reality are related through the “measurement problem” in quantum mechanics, i.e., why we do not consciously perceive particles as quantum superpositions of multiple possibilities, as they appear to be when unobserved, but rather perceive them consciously as being in definite states or locations. Quantum pioneers Niels Bohr, John von Neumann, Eugene Wigner, and Henry Stapp concluded that subjective conscious observation causes quantum state reduction (“subjective reduction” (SR)), that “consciousness collapses the wavefunction.” However, Sir Roger Penrose suggested instead that quantum state reduction occurs spontaneously due to an objective threshold property (“objective reduction” (OR)) in fundamental spacetime geometry, collapsing the wave function and causing moments of conscious experience (“collapse causes consciousness,” or “collapse is consciousness”). Penrose OR would be occurring ubiquitously and randomly in the environment (“decoherence”) resulting in ubiquitous proto-conscious moments. The Penrose–Hameroff “Orch OR” model of orchestrated objective reduction suggests that microtubules inside brain neurons “orchestrate” quantum computations which “halt” by Orch OR to produce moments of a full, rich conscious experience.


Consciousness Quantum state reduction Quantum computing Measurement problem Spacetime geometry Orch OR Microtubule Tubulin Anesthesia Superposition Henry Stapp Roger Penrose Subjective reduction Objective reduction 


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Conflict of Interest

The author declares that there is no conflict of interest.


  1. Craddock, T.J.A., St George, M., Freedman, H., Barakat, K.H., Damaraju, S., Hameroff, S., Tuszynski, J.A. (2012). Computational predictions of volatile anesthetic interactions with the microtubule cytoskeleton: Implications for side effects of general anesthesia. PLoS One 7: e37251.Google Scholar
  2. Craddock, T. J. A., Hameroff, S. R., Ayoub, A. T., Klobukowski, M., & Tuszynski, J. A. (2015). Anesthetics act in quantum channels in brain microtubules to prevent consciousness. Current Topics in Medicinal Chemistry, 15, 523–533.CrossRefPubMedGoogle Scholar
  3. Craddock, T.J.A., Kurian, P., Preto, J., Sahu, K., Hameroff, S.R., Klobukowski, M., Tuszynski, J.A. (2017). Anesthetic Alterations of Collective Terahertz Oscillations in Tubulin Correlate with Clinical Potency: Implications for Anesthetic Action and Post-Operative Cognitive Dysfunction. Scientific Reports, 7, 9877.Google Scholar
  4. Dennis, E., Preskill, J. (2002). Topological quantum memory. Journal of Mathematical Physics, 43, 4452.Google Scholar
  5. Emerson, D., Weiser, B., Psonis, J., Liao, Z., Taratula, O., Fiamengo, A., et al. (2013). Direct modulation of microtubule stability contributes to anthracene general anesthesia. Journal of the American Chemical Society, 135(14), 5398.Google Scholar
  6. Everett, H., (1955). Relative state formulation of quantum mechanics. Reviews of Modern Physics 29, 454–462.Google Scholar
  7. Fröhlich, H.(1968). Long range coherence and energy storage in biological systems. International Journal of Quantum Chemistry, 2, 641–649.Google Scholar
  8. Fröhlich, H. (1970). Long range coherence and the actions of enzymes. Nature, 228, 1093.CrossRefPubMedGoogle Scholar
  9. Fröhlich, H. (1975). The extraordinary dielectric properties of biological materials and the action of enzymes. Proceedings of the National Academy of Sciences of the United States of America, 72, 4211–4215.CrossRefPubMedPubMedCentralGoogle Scholar
  10. Hagan, S., Hameroff, S., & Tuszynski, J. (2001). Quantum computation in brain microtubules? Decoherence and biological feasibility. Physical Review E, 65, 061901.CrossRefGoogle Scholar
  11. Hameroff, S. (1998a). Quantum computation in brain microtubules? The Penrose–Hameroff “Orch OR” model of consciousness. Philosophical Transactions of the Royal Society of London. Series A: Mathematical Physical and Engineering Sciences, 356(1998), 1869–1896.Google Scholar
  12. Hameroff, S. (1998b). Anesthesia, consciousness and hydrophobic pockets – A unitary quantum hypothesis of anesthetic action. Toxicology Letters, 100(101), 31–39.CrossRefPubMedGoogle Scholar
  13. Hameroff, S., & Penrose, R. (1996a). Orchestrated reduction of quantum coherence in brain microtubules: a model for consciousness. Mathematics and Computers in Simulation, 40, 453–480.CrossRefGoogle Scholar
  14. Hameroff, S., & Penrose, R. (1996b). Conscious events as orchestrated space–time selections. Journal of Consciousness Studies, 3(1), 36–53.Google Scholar
  15. Hameroff, S., & Penrose, R. (2014). Consciousness in the universe: A review of the ‘Orch OR’theory. Physics of Life Reviews, 11, 39–78.CrossRefPubMedGoogle Scholar
  16. Hameroff, S, & Penrose, R. (2016). Consciousness in the universe: A review of the ‘Orch OR’theory, In: Biophysics of Consciousness: A Foundational Approach Eds: RR Poznanski, JA Tuszynski, TE Feinberg, World Scientific, Singapore.Google Scholar
  17. Hameroff, S., & Watt, R. (1983). Do anesthetics act by altering electron mobility? Anesthesia and Analgesia, 62, 936–940.CrossRefPubMedGoogle Scholar
  18. Hameroff, S., Nip, A., Porter, M., & Tuszynski, J. (2002). Conduction pathways in microtubules, biological quantum computation, and consciousness. Biosystems, 64, 149–168.CrossRefPubMedGoogle Scholar
  19. Hameroff, S. R. (1998). Funda-mentality’: is the conscious mind subtly linked to a basic level of the universe? Trends in Cognitive Sciences, 2, 119–127.CrossRefPubMedGoogle Scholar
  20. Hameroff, S. R., & Watt, R. C. (1982). Information processing in microtubules. Journal of Theoretical Biology, 98, 549–561.CrossRefPubMedGoogle Scholar
  21. Ghirardi, G.C., Rimini, A., Weber, T. (1986). Unified dynamics for microscopic and macroscopic systems. Physical Review D, 34, 470.Google Scholar
  22. Koch, C., (2012). Consciousness: Confessions of a Romantic Reductionist, MIT Press, Cambridge MA.Google Scholar
  23. Pan, J. Z., Xi, J., Tobias, J. W., Eckenhoff, M. F., & Eckenhoff, R. G. (2007). Halothane binding proteome in human brain cortex. Journal of Proteome Research, 6, 582–592.CrossRefPubMedGoogle Scholar
  24. Pan, J. Z., Xi, J., Eckenhoff, M. F., & Eckenhoff, R. G. (2008). Inhaled anesthetics elicit region-specific changes in protein expression in mammalian brain. Proteomics, 8, 2983–2992.CrossRefPubMedGoogle Scholar
  25. Penrose, R. (1989). The emperor’s new mind: Concerning computers, minds, and the laws of physics. Oxford: Oxford University Press.Google Scholar
  26. Penrose, R. (1994). Shadows of the mind: An approach to the missing science of consciousness. Oxford: Oxford University Press.Google Scholar
  27. Penrose, R. (1996). On gravity’s role in quantum state reduction. General Relativity and Gravitation, 28, 581–600.CrossRefGoogle Scholar
  28. Penrose, R. (2004). The road to reality: a complete guide to the laws of the universe Jonathan Cape, London.Google Scholar
  29. Penrose, R., & Hameroff, S. (1995). What gaps? Reply to Grush and Churchland. Journal of Consciousness Studies, 2, 98–112.Google Scholar
  30. Rasmussen, S., Karampurwala, H., Vaidyanath, R., Jensen, K., & Hameroff, S. (1990). Computational connectionism within neurons: A model of cytoskeletal automata subserving neural networks. Physica D: Nonlinear Phenomena, 42, 428–449.CrossRefGoogle Scholar
  31. Sahu, S., Ghosh, S., Ghosh, B., Aswani, K., Hirata, K., Fujita, D., et al. (2013a). Atomic water channel controlling remarkable properties of a single brain microtubule: Correlating single protein to its supramolecular assembly. Biosensors & Bioelectronics, 47, 141–148.CrossRefGoogle Scholar
  32. Sahu, S., Ghosh, S., Hirata, K., Fujita, D., & Bandyopadhyay, A. (2013b). Multi-level memory-switching properties of a single brain microtubule. Applied Physics Letters, 102, 123701.CrossRefGoogle Scholar
  33. Sahu, S., Ghosh, S., Fujita, D., Bandyopadhyay, A. (2014). Live visualizations of single isolated tubulin protein self-assembly via tunneling current: effect of electromagnetic pumping during spontaneous growth of microtubule, Scientific Reports, 4, 7303.Google Scholar
  34. Sataric, M.V., Zekovic, S., Tuszynski, J.A., Pokorny, J. (1998). The Mossbauer effect as a possible tool in detecting nonlinear excitations in microtubules. Physical Review E, 58, 6333–6339.Google Scholar
  35. Smith, S., Watt, R., & Hameroff, S. (1984). Cellular automata in cytoskeletal lattice proteins. Physica D, 10, l68–l74.CrossRefGoogle Scholar
  36. Stapp, H.P.. (1993) Mind, matter and quantum mechanics, Springer-Verlag, Berlin, Heidelberg.Google Scholar
  37. Stapp, H.P.. (2007) Mindful universe: Quantum mechanics and the participating observer. Springer.Google Scholar
  38. Tegmark, M. (2000). The importance of quantum decoherence in brain processes. Physical Review E, 61, 4194–4206.CrossRefGoogle Scholar
  39. Tononi, G. (2012). Phi: A voyage from the brain to the soul Pantheon Books, New York.Google Scholar
  40. Whitehead, A. N. (1929). Process and reality. New York (NY): MacMillan.Google Scholar
  41. Whitehead, A. N. (1933). Adventure of ideas. London: MacMillan.Google Scholar
  42. Wigner, E.P. (1961). Remarks on the mind body question, In: J.A. Wheeler, W.H. Zurek (Eds.) Quantum theory and measurement, Princeton University Press, Princeton.Google Scholar
  43. Xi, J., Liu, R., Asbury, G. R., Eckenhoff, M. F., & Eckenhoff, R. G. (2004). Inhalational anesthetic-binding proteins in rat neuronal membranes. Journal of Biological Chemistry, 279, 19628–19633.CrossRefPubMedGoogle Scholar

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© Neuroscientia 2019

Authors and Affiliations

  1. 1.Anesthesiology and Psychology, Center for Consciousness StudiesThe University of ArizonaTucsonUSA

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