The brain is both neurocomputer and quantum computer
Abstract
In their article, Is the Brain a Quantum Computer,? Litt, Eliasmith, Kroon, Weinstein, and Thagard (2006) criticize the Penrose-Hameroff "Orch OR" quantum computational model of consciousness, arguing instead for neurocomputation as an explanation for mental phenomena. Here I clarify and defend Orch OR, show how Orch OR and neurocomputation are compatible, and question whether neurocomputation alone can physiologically account for coherent gamma synchrony EEG, a candidate for the neural correlate of consciousness. Orch OR is based on quantum computation in microtubules within dendrites in cortex and other regions linked by dendritic-dendritic gap junctions ("dendritic webs") acting as laterally connected input layers of the brain's neurocomputational architecture. Within dendritic webs, consciousness is proposed to occur as gamma EEG-synchronized sequences of discrete quantum computational events acting in integration phases of neurocomputational "integrate-and-fire" cycles. Orch OR is a viable approach toward understanding how the brain produces consciousness.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
MT-based information processing offers a huge potential increase in brain capacity.
“MT-based information processing offers a huge potential increase in brain capacity [74].”
From Consciousness in the universe (2014) · cites this paper as [74]
Cites
The conscious mind: in search of a fundamental theory
(1996) · Choice Reviews Online · doi:10.5860/choice.34-2091 · Cited by 4,150 · see citing works
Evidence for wavelike energy transfer through quantum coherence in photosynthetic systems
Engel, G. S., Calhoun, T. R., Read, E. L., Ahn, T.-K., Mančal, T., Cheng, Y.-C., Blankenship, R. E., & Fleming, G. R. (2007) · Nature · doi:10.1038/nature05678 · Cited by 3,315 · see citing works
Neuronal Synchrony: A Versatile Code for the Definition of Relations?
Singer, W. (1999) · Neuron · doi:10.1016/s0896-6273(00)80821-1 · Cited by 2,581 · see citing works
The Emperor's New Mind: Concerning Computers, Minds, and The Laws of Physics
Penrose, R., & Gardner, M. (1989) · doi:10.1093/oso/9780198519737.001.0001 · Cited by 2,007 · see citing works
On gravity's role in quantum state reduction
Penrose, R. (1996) · General Relativity and Gravitation · doi:10.1007/bf02105068 · Cited by 1,872 · see citing works
The Illusion of Conscious Will
Wegner, D. M., Gilbert, D. T., & Wheatley, T. P. (2018) · The MIT Press eBooks · doi:10.7551/mitpress/9780262534925.001.0001 · Cited by 1,646 · see citing works
Two networks of electrically coupled inhibitory neurons in neocortex
Gibson, J. R., Beierlein, M., & Connors, B. W. (1999) · Nature · doi:10.1038/47035 · Cited by 1,404 · see citing works
Long-term meditators self-induce high-amplitude gamma synchrony during mental practice
Lutz, A., Greischar, L. L., Rawlings, N. B., Ricard, M., & Davidson, R. J. (2004) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0407401101 · Cited by 1,328 · see citing works
(1994) · CERN Document Server (European Organization for Nuclear Research) · Cited by 1,062 · see citing works
Time and the observer: The where and when of consciousness in the brain
Dennett, D. C., & Kinsbourne, M. (1992) · Behavioral and Brain Sciences · doi:10.1017/s0140525x00068229 · Cited by 1,015 · see citing works
A network of fast-spiking cells in the neocortex connected by electrical synapses
Galarreta, M., & Hestrin, S. (1999) · Nature · doi:10.1038/47029 · Cited by 960 · see citing works
Rakover, S. S. (1994) · International Studies in Philosophy · doi:10.5840/intstudphil1994262128 · Cited by 854 · see citing works
Electrical Coupling and Neuronal Synchronization in the Mammalian Brain
Bennett, M. V. L., & Zukin, R. S. (2004) · Neuron · doi:10.1016/s0896-6273(04)00043-1 · Cited by 819 · see citing works
The quest for consciousness: a neurobiological approach
(2004) · Choice Reviews Online · doi:10.5860/choice.42-1543 · Cited by 815 · see citing works
Importance of quantum decoherence in brain processes
Tegmark, M. (2000) · Physical Review E · doi:10.1103/physreve.61.4194 · Cited by 776 · see citing works
Electrical coupling underlies high-frequency oscillations in the hippocampus in vitro
Draguhn, A., Traub, R. D., Schmitz, D., & Jefferys, J. G. R. (1998) · Nature · doi:10.1038/28184 · Cited by 703 · see citing works
Is human information processing conscious?
Velmans, M. (1991) · Behavioral and Brain Sciences · doi:10.1017/s0140525x00071776 · Cited by 677 · see citing works
Proximally targeted GABAergic synapses and gap junctions synchronize cortical interneurons
Tamás, G., Buhl, E. H., Lörincz, A., & Somogyi, P. (2000) · Nature Neuroscience · doi:10.1038/73936 · Cited by 648 · see citing works
Orchestrated reduction of quantum coherence in brain microtubules: a model for consciousness
Hameroff, S., & Penrose, R. (1996) · Mathematics and Computers in Simulation · doi:10.1016/0378-4754(96)80476-9 · Cited by 641 · see citing works
Self-citationShadlen, M. N., & Movshon, J. A. (1999) · Neuron · doi:10.1016/s0896-6273(00)80822-3 · Cited by 606 · see citing works
LIBET, B., WRIGHT, E. W. W., FEINSTEIN, B., & PEARL, D. K. (1979) · Brain · doi:10.1093/brain/102.1.193 · Cited by 589 · see citing works
Neuronal Coherence as a Mechanism of Effective Corticospinal Interaction
Schoffelen, J., Oostenveld, R., & Fries, P. (2005) · Science · doi:10.1126/science.1107027 · Cited by 519 · see citing works
The Illusion of Conscious Will
Wegner, D., Gilbert, D. T., & Wheatley, T. (2018) · The MIT Press · doi:10.7551/mitpress/3650.001.0001 · Cited by 484 · see citing works
Quantum computation in brain microtubules: decoherence and biological feasibility
Hagan, S., Hameroff, S. R., & Tuszyński, J. A. (2002) · Physical Review E · doi:10.1103/physreve.65.061901 · Cited by 389 · see citing works
Self-citation(1996) · Journal of Consciousness Studies · Cited by 385 · see citing works
Quantum computation in brain microtubules? The Penrose–Hameroff ‘Orch OR‘ model of consciousness
Hameroff, S. R. (1998) · Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences · doi:10.1098/rsta.1998.0254 · Cited by 368 · see citing works
Self-citationTraub, R. D., Kopell, N., Bibbig, A., Buhl, E. H., LeBeau, F. E. N., & Whittington, M. A. (2001) · Journal of Neuroscience · doi:10.1523/jneurosci.21-23-09478.2001 · Cited by 357 · see citing works
Gap junctions and connexin expression in the normal and pathological central nervous system
Rouach, N., Avignone, E., Même, W., Koulakoff, A., Venance, L., Blomstrand, F., & Giaume, C. (2002) · Biology of the Cell · doi:10.1016/s0248-4900(02)00016-3 · Cited by 345 · see citing works
Electrical synapses: a dynamic signaling system that shapes the activity of neuronal networks
Hormuzdi, S. G., Filippov, M. A., Mitropoulou, G., Monyer, H., & Bruzzone, R. (2004) · Biochimica et Biophysica Acta (BBA) - Biomembranes · doi:10.1016/j.bbamem.2003.10.023 · Cited by 329 · see citing works
Gap junctions, synchrony and seizures
Velázquez, J. L. P., & Carlen, P. L. (2000) · Trends in Neurosciences · doi:10.1016/s0166-2236(99)01497-6 · Cited by 272 · see citing works
Selective Impairment of Hippocampal Gamma Oscillations in Connexin-36 Knock-Out MouseIn Vivo
Buhl, D. L., Harris, K. D., Hormuzdi, S. G., Monyer, H., & Buzsáki, G. (2003) · Journal of Neuroscience · doi:10.1523/jneurosci.23-03-01013.2003 · Cited by 264 · see citing works
Nonlinear brain dynamics as macroscopic manifestation of underlying many-body field dynamics
FREEMAN, W., & VITIELLO, G. (2006) · Physics of Life Reviews · doi:10.1016/j.plrev.2006.02.001 · Cited by 255 · see citing works
Coherent spin transfer between molecularly bridged quantum dots
Ouyang, M., & Awschalom, D. D. (2003) · Science · doi:10.1126/science.1086963 · Cited by 254 · see citing works
John, E. R., & Prichep, L. S. (2005) · Anesthesiology · doi:10.1097/00000542-200502000-00030 · Cited by 250 · see citing works
Current-Induced Polarization and the Spin Hall Effect at Room Temperature
Stern, N. P., Ghosh, S., Xiang, G., Zhu, M., Samarth, N., & Awschalom, D. D. (2006) · Physical Review Letters · doi:10.1103/physrevlett.97.126603 · Cited by 236 · see citing works
The spatial dimensions of electrically coupled networks of interneurons in the neocortex
Amitai, Y., Gibson, J. R., Beierlein, M., Patrick, S. L., Ho, A. M., Connors, B. W., & Golomb, D. (2002) · The Journal of Neuroscience · doi:10.1523/jneurosci.22-10-04142.2002 · Cited by 235 · see citing works
Subjective Referral of the Timing for a Conscious Sensory Experience
Libet, B., Wright, E. W., FEINSTEIN, B., & Pearl, D. K. (1993) · Birkhäuser Boston eBooks · doi:10.1007/978-1-4612-0355-1_9 · Cited by 232 · see citing works
Traub, R. D., Draguhn, A., Whittington, M. A., Baldeweg, T., Bibbig, A., Buhl, E. H., & Schmitz, D. (2002) · Reviews in the Neurosciences · doi:10.1515/revneuro.2002.13.1.1 · Cited by 225 · see citing works
Gap junctions in the nervous system.
Rozental, R., Giaume, C., & Spray, D. (2000) · Brain research. Brain research reviews · doi:10.1016/s0165-0173(99)00095-8 · Cited by 219 · see citing works
A field theory of consciousness.
John, E. R. (2001) · Consciousness and Cognition · doi:10.1006/ccog.2001.0508 · Cited by 214 · see citing works
Toward a Science of Consciousness
(1996) · The MIT Press eBooks · doi:10.7551/mitpress/6860.001.0001 · Cited by 212 · see citing works
Fukuda, T., Kosaka, T., Singer, W., & Galuske, R. A. W. (2006) · The Journal of Neuroscience · doi:10.1523/jneurosci.4076-05.2006 · Cited by 209 · see citing works
Conscious Events as Orchestrated Space-Time Selections
Hameroff, S. R., & Penrose, R. (2007) · NeuroQuantology · doi:10.14704/nq.2003.1.1.3 · Cited by 201 · see citing works
Self-citationSite‐specific and developmental expression of pannexin1 in the mouse nervous system
Ray, A., Zoidl, G., Weickert, S., Wahle, P., & Dermietzel, R. (2005) · European Journal of Neuroscience · doi:10.1111/j.1460-9568.2005.04139.x · Cited by 200 · see citing works
Conduction pathways in microtubules, biological quantum computation, and consciousness
Hameroff, S. R., Nip, A. M. L., Porter, M., & Tuszyński, J. A. (2002) · Biosystems · doi:10.1016/s0303-2647(01)00183-6 · Cited by 198 · see citing works
Self-citationImas, O. A., Ropella, K. M., Ward, B. D., Wood, J. D., & Hudetz, A. G. (2005) · Neuroscience Letters · doi:10.1016/j.neulet.2005.06.018 · Cited by 189 · see citing works
Nonlinear brain dynamics as macroscopic manifestation of underlying many-body field dynamics
Freeman, W. J., III, & Vitiello, G. (2006) · eScholarship (California Digital Library) · Cited by 184 · see citing works
Eccles, J. C. (1992) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.89.16.7320 · Cited by 180 · see citing works
Could Humans Recognize Odor by Phonon Assisted Tunneling?
Brookes, J. C., Hartoutsiou, F., Horsfield, A. P., & Stoneham, A. M. (2007) · Physical Review Letters · doi:10.1103/physrevlett.98.038101 · Cited by 179 · see citing works
Toward a Science of Consciousness II: The Second Tucson Discussions and Debates
Ameroff, S., Kaszniak, A. W., & Scott, A. C. (1998) · Medical Entomology and Zoology · Cited by 167 · see citing works
Rasmussen, S., Karampurwala, H., Vaidyanath, R., Jensen, K. S., & Hameroff, S. (1990) · Physica D Nonlinear Phenomena · doi:10.1016/0167-2789(90)90093-5 · Cited by 153 · see citing works
Self-citationThe Entwined Mysteries of Anesthesia and Consciousness: Is There a Common Underlying Mechanism?
Hameroff, S. R. (2006) · Anesthesiology · doi:10.1097/00000542-200608000-00024 · Cited by 129 · see citing works
Self-citationIs the Brain a Quantum Computer?
Litt, A., Eliasmith, C., Kroon, F. W., Weinstein, S., & Thagard, P. R. (2006) · Cognitive Science · doi:10.1207/s15516709cog0000_59 · Cited by 121 · see citing works
Both Electrical and Chemical Synapses Mediate Fast Network Oscillations in the Olfactory Bulb
Friedman, D., & Strowbridge, B. W. (2003) · Journal of Neurophysiology · doi:10.1152/jn.00887.2002 · Cited by 120 · see citing works
Dermietzel, R. (1998) · Brain Research Reviews · doi:10.1016/s0165-0173(97)00031-3 · Cited by 117 · see citing works
Thermally Assisted Adiabatic Quantum Computation
Amin, M. H. S., Love, P. J., & Truncik, C. J. S. (2008) · Physical Review Letters · doi:10.1103/physrevlett.100.060503 · Cited by 115 · see citing works
Koch, C., & Crick, F. H. C. (2001) · Nature · doi:10.1038/35082161 · Cited by 112 · see citing works
(1995) · Journal of Consciousness Studies · Cited by 111 · see citing works
A structural basis for memory storage in mammals.
Woolf, N. (1998) · Progress in neurobiology · doi:10.1016/s0301-0082(97)00094-4 · Cited by 109 · see citing works
A quantum approach to visual consciousness
Woolf, N. J., & Hameroff, S. R. (2001) · Trends in Cognitive Sciences · doi:10.1016/s1364-6613(00)01774-5 · Cited by 106 · see citing works
Self-citationA relationship between the hallucinogenic activity of drugs and their electronic configuration.
Snyder, S. H., & Merril, C. R. (1965) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.54.1.258 · Cited by 92 · see citing works
The role of electrical signaling via gap junctions in the generation of fast network oscillations
LeBeau, F. E. N., Traub, R. D., Monyer, H., Whittington, M. A., & Buhl, E. H. (2003) · Brain Research Bulletin · doi:10.1016/j.brainresbull.2003.07.004 · Cited by 86 · see citing works
John, E. R. (1976) · Springer eBooks · doi:10.1007/978-1-4684-2568-0_1 · Cited by 69 · see citing works
Consciousness, Neurobiology and Quantum Mechanics: The Case for a Connection
Hameroff, S. R. (2006) · Springer eBooks · doi:10.1007/3-540-36723-3_6 · Cited by 65 · see citing works
Self-citationSteric and Electronic Relationships among Some Hallucinogenic Compounds
Kang, S., & Green, J. P. (1970) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.67.1.62 · Cited by 64 · see citing works
Anesthesia, consciousness and hydrophobic pockets–a unitary quantum hypothesis of anesthetic action
Hameroff, S. (1998) · Toxicology Letters · doi:10.1016/s0378-4274(98)00162-3 · Cited by 62 · see citing works
Orchestrated Reduction of Quantum Coherence in Brain Microtubules: A Model for Consciousness
Hameroff, S. R. (2007) · NeuroQuantology · doi:10.14704/nq.2007.5.1.114 · Cited by 48 · see citing works
Self-citationHow Molecules Matter to Mental Computation
Thagard, P. R. (2002) · Philosophy of Science · doi:10.1086/342452 · Cited by 43 · see citing works
(1998) · The MIT Press eBooks · doi:10.7551/mitpress/5123.003.0015 · Cited by 41 · see citing works
Rasmussen, S., Karampurwala, H., Vaidyanath, R., Jensen, K. S., & Hameroff, S. R. (1991) · Cited by 35 · see citing works
Self-citationBiochemical and Chemical Properties of Tubulin Subspeciesa
Lee, J. C., Field, D. J., George, H. J., et al. (1986) · Annals of the New York Academy of Sciences · doi:10.1111/j.1749-6632.1986.tb38388.x · Cited by 31 · see citing works
Studies of the relationship between molecular structure and hallucinogenic activity
Nichols, D. E. (1986) · Pharmacology Biochemistry and Behavior · doi:10.1016/0091-3057(86)90362-x · Cited by 23 · see citing works
Hervé, J. (2004) · Biochimica et Biophysica Acta (BBA) - Biomembranes · doi:10.1016/j.bbamem.2004.02.001 · Cited by 19 · see citing works
Coupled heterocellular arrays in the brain
Fróes, M. M., & Menezes, J. R. L. (2002) · Neurochemistry International · doi:10.1016/s0197-0186(02)00016-5 · Cited by 15 · see citing works
Room temperature electron spin coherence in telecom-wavelength quaternary quantum wells
Lau, W. H., Sih, V., Stern, N. P., et al. (2006) · Applied Physics Letters · doi:10.1063/1.2358931 · Cited by 13 · see citing works
Flagged first, then by citations
Cited by
Sorted by citations
Hameroff, S., & Penrose, R. (2014) · Physics of Life Reviews · doi:10.1016/j.plrev.2013.08.002 · Cited by 983 · see citing works
“Naundorf et al. [43] showed that firing threshold at the AIS in cortical neurons in brains of awake animals (compared to neurons in vitro) vary significantly spike-to-spike (Fig.”
BackgroundSelf-citationPothos, E. M., & Busemeyer, J. R. (2022) · Annual Review of Psychology · doi:10.1146/annurev-psych-033020-123501 · Cited by 184 · see citing works
The ‘conscious pilot’ — dendritic synchrony moves through the brain to mediate consciousness.
Hameroff, S. (2010) · Journal of Biological Physics · doi:10.1007/s10867-009-9148-x · Cited by 107 · see citing works
Self-citationHow quantum brain biology can rescue conscious free will
Hameroff, S. (2012) · Frontiers in Integrative Neuroscience · doi:10.3389/fnint.2012.00093 · Cited by 95 · see citing works
Self-citationTang, R., & Dai, J. (2014) · PLoS ONE · doi:10.1371/journal.pone.0085643 · Cited by 91 · see citing works
McKemmish, L. K., Reimers, J. R., McKenzie, R. H., Mark, A. E., & Hush, N. S. (2009) · Physical Review E · doi:10.1103/physreve.80.021912 · Cited by 87 · see citing works
Quantum effects in the brain: A review
Adams, B., & Petruccione, F. (2020) · AVS Quantum Science · doi:10.1116/1.5135170 · Cited by 80 · see citing works
A quantum–classical model of brain dynamics
Sergi, A., Messina, A., Vicario, C. M., & Martino, G. (2023) · Entropy · doi:10.3390/e25040592 · Cited by 16 · see citing works
Quantum Models of Consciousness from a Quantum Information Science Perspective
Gassab, L., Pusuluk, O., Cattaneo, M., & Müstecaplıoğlu, Ö. E. (2025) · Entropy · doi:10.3390/e27030243 · Cited by 14 · see citing works
McDonnell, A. (2014) · Journal of Behavioral and Brain Science · doi:10.4236/jbbs.2014.47035 · Cited by 6 · see citing works
- Authors
- Hameroff, S. R.
- Affiliations
- University of Arizona (US)
- Corresponding author
- Hameroff, Stuart R.
- ORCID
- Hameroff, Stuart R.
- Venue
- Cognitive Science
- Publisher
- Wiley
- Published
- 2007-11
- Volume
- 31
- Issue
- 6
- Pages
- 1035-1045
- ISSN
- 0364-0213 (ISSN-L)
- 1551-6709
- OpenAlex
- W2135027517
- Cited by
- 103
- References
- 76
- Citations by year
- 2026: 1 · 2025: 6 · 2024: 5 · 2023: 3 · 2022: 6 · 2021: 3 · 2020: 2 · 2019: 3 · 2018: 7 · 2017: 3 · 2016: 8 · 2015: 4 · 2014: 12 · 2013: 12 · 2012: 8
- FWCI
- 7.29
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Cognitive Science (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Philosophy and Theoretical Science
- Life Sciences › Neuroscience › Cognitive Neuroscience › Neural dynamics and brain function
- Health Sciences › Medicine › Physiology › Biofield Effects and Biophysics
- Keywords
- Orchestrated Objective Reduction, Penrose-Hameroff, neural computation, consciousness, microtubules, gamma synchrony, EEG, neural correlates of consciousness, gap junctions
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
