Hameroff in 2008
16 July 1947|
Buffalo, New York, United States
|Residence||Tucson, Arizona, United States|
University of Pittsburgh (B.S.)|
Hahnemann University Hospital (M.D.)
|Known for||Consciousness studies|
|Institutions||University of Arizona|
Stuart Hameroff (born July 16, 1947) is an anesthesiologist and professor at the University of Arizona known for his studies of consciousness and his controversial contention that quantum states in neural microtubules are responsible for its emergence. He is the lead organizer of the Science of Consciousness conference.
Hameroff received his BS degree from the University of Pittsburgh and his MD degree from Hahnemann University Hospital, where he studied before it became part of the Drexel University College of Medicine. He took an internship at the Tucson Medical Center in 1973. From 1975 onwards, he has spent the whole of his career at the University of Arizona, becoming professor in the Department of Anesthesiology and Psychology and director for the Center for Consciousness Studies, both in 1999, and finally Emeritus professor for Anesthesiology and Psychology in 2003.
At the very beginning of Hameroff's career, while he was at Hahnemann, cancer-related research work piqued his interest in the part played by microtubules in cell division, and led him to speculate that they were controlled by some form of computing. It also suggested to him that part of the solution of the problem of consciousness might lie in understanding the operations of microtubules in brain cells, operations at the molecular and supramolecular level.
The operations of microtubules are remarkably complex and their role pervasive in cellular operations; these facts led to the speculation that computation sufficient for consciousness might somehow be occurring there. These ideas are discussed in Hameroff's first book Ultimate Computing (1987). The main substance of this book dealt with the scope for information processing in biological tissue and especially in microtubules and other parts of the cytoskeleton. Hameroff argued that these subneuronal cytoskeleton components could be the basic units of processing rather than the neurons themselves. The book was primarily concerned with information processing, with consciousness secondary at this stage.
Separately from Hameroff, the English mathematical physicist Roger Penrose had published his first book on consciousness, The Emperor's New Mind, in 1989. On the basis of Gödel's incompleteness theorems, he argued that the brain could perform functions that no computer or system of algorithms could. From this it could follow that consciousness itself might be fundamentally non-algorithmic, and incapable of being modeled as a classical Turing machine type of computer. This ran counter to the belief that it could be explained mechanistically, which was prevalent in the field of artificial Intelligence at that time.
Penrose saw the principles of quantum theory as providing an alternative process through which consciousness could arise. He further argued that this non-algorithmic process in the brain required a new form of the quantum wave reduction, later given the name objective reduction (OR), which could link the brain to the fundamental spacetime geometry. At this stage, he had no precise ideas as to how such a quantum process might be instantiated in the brain. Moreover, Penrose's ideas were widely criticized by neuroscientists, logicians and philosophers, notably Grush and Churchland.
Hameroff was inspired by Penrose's book to contact Penrose regarding his own theories about the mechanism of anesthesia, and how it specifically targets consciousness via action on neural microtubules. The two met in 1992, and Hameroff suggested that the microtubules were a good candidate site for a quantum mechanism in the brain. Penrose was interested in the mathematical features of the microtubule lattice, and over the next two years the two collaborated in formulating the orchestrated objective reduction (Orch-OR) model of consciousness. Following this collaboration, Penrose published his second consciousness book, Shadows of the Mind (1994).
Over the years since 1994, Hameroff has been active in promoting the Orch-OR model of consciousness through his web site and lectures.
This more developed version of their ideas was widely attacked, notably in 2000 by the physicist Max Tegmark, who calculated that quantum states in microtubules would survive for only 10−13 seconds, too brief to be of any significance for neural processes. Hameroff and the physicists Scott Hagan and Jack Tuszynski replied to Tegmark arguing that microtubules could be shielded against the environment of the brain, and that Tegmark had used his own criteria for the reduction of the wavefunction, and did not use Penrose's OR, which is the basic assumption behind the whole theory. In 2014, experimental confirmation of shielding, and most notably of quantum coherence in microtubuli, was found by Anirban Bandyopadhyay.
Toward a Science of Consciousness
Hameroff was the lead organizer of the first Tucson Toward a Science of Consciousness meeting in 1994 that brought together approximately 300 people interested in consciousness studies (e.g., David Chalmers, Christof Koch, Bernard Baars, Roger Penrose, Benjamin Libet). Hameroff remains co-organizer of this influential annual conference (now simply Science of Consciousness). The first conference is widely regarded as a landmark event within the field of consciousness studies, and by bringing researchers from various disciplines together led to various useful synergies, resulting indirectly, for instance, in the formation of the Association for the Scientific Study of Consciousness, and more directly in the creation of the Center for Consciousness Studies at the University of Arizona, of which Hameroff is now the director. The Center for Consciousness Studies hosts meetings on the study of consciousness every two years, as well as sponsoring seminars on consciousness theory. The conference was described by the Chronicle of Higher Education as "the Stuart Show", and that its "anything goes" atmosphere is damaging the credibility of the field.
Hameroff appeared as himself in the documentary film What tнe ♯$*! Do ωΣ (k)πow!? (2004). He serves as producer, writer and scientific advisor to an independent feature film called Mindville. Mindville is a feature-length motion picture that combines live action with animation and effects to present a journey into the mysteries of human consciousness.
- Danaylov, Nikola, ed. (12 Sep 2013). Stuart Hameroff on Singularity 1 on 1: Consciousness is More than Computation!. Singularity Weblog. Retrieved 24 March 2014.
Consciousness is the most important thing there is!
- Hameroff, Stuart (1987), Ultimate Computing, Elsevier ISBN 978-0444702838
- Penrose, Roger (1989) The Emperor's New Mind Oxford University Press
- Grush Rick, Churchland Patricia (1995). "Gap's in Penrose's Toilings". Journal of Consciousness Studies. 2 (1): 10–29. (also see article at IngentaConnect)
- Penrose, Roger (1994) Shadows of the Mind Oxford University Press
- "Quantum Consciousness - Quantum Consciousness".
- Tegmark Max (2000). "Importance of quantum coherence in brain processes". Physical Review E. 61: 4194–4206. arXiv: . Bibcode:2000PhRvE..61.4194T. doi:10.1103/physreve.61.4194.
- Tegmark, Max (October 2000). "Why the brain is probably not a quantum computer" (PDF). Information Sciences. 128 (3-4): 155–179. doi:10.1016/S0020-0255(00)00051-7.
- Hagan Scott, Hameroff Stuart R, Tuszyński Jack A (2002). "Quantum computation in brain microtubules: Decoherence and biological feasibility". Physical Review E. 65: 061901. arXiv: . Bibcode:2002PhRvE..65f1901H. doi:10.1103/physreve.65.061901.
- Anirban Bandyopadhyay (26 March 2013). "Multi-level memory-switching properties of a single brain microtubule". Applied Physics Letters. American Institute of Physics. 102 (12): 123701. Bibcode:2013ApPhL.102l3701S. doi:10.1063/1.4793995. Retrieved 16 March 2014.
- Anirban Bandyopadhyay (15 March 2013). "Atomic water channel controlling remarkable properties of a single brain microtubule: correlating single protein to its supramolecular assembly". Biosens Bioelectron. Elsevier. 47 (12): 141–8. doi:10.1016/j.bios.2013.02.050. PMID 23567633.
- Bartlett, Tom (6 June 2018). "Has Consciousness Lost Its Mind?". The Chronicle of Higher Education. Archived from the original on 17 June 2018. Retrieved 19 June 2018.
- Hameroff, Stuart; Ramachandran, V.S. (November 5, 2006). "Beyond Belief: Science, Reason, Religion & Survival: Session 4". The Science Network. Retrieved 2012-08-13.
- Stuart Hameroff (2006) "Consciousness, neurobiology and quantum mechanics," in: Jack A. Tuszynski (5 September 2006). The Emerging Physics of Consciousness. Springer Science & Business Media. pp. 192–251. ISBN 978-3-540-36723-9.
- Stuart Hameroff with Conrad Schneiker, Ultimate Computing: Biomolecular Consciousness and Nanotechnology, Elsevier-North Holland, 1987. This work predates the quantum Orch-OR hypothesis; still of interest. Online at author's site
- Hameroff, Kaszniak, Scott, (eds), Toward a Science of Consciousness, MIT Press, ISBN 0-262-08249-7, LoC OP411.T68 1996. papers from the first Tucson conference on study of consciousness. Further volumes in the series exist.
- Roger Penrose, Shadows of the Mind: A Search for the Missing Science of Consciousness, Oxford, ISBN 0-19-853978-9, LoC Q335.P416 1994. This discusses the Orch-OR theory.