Stuart Hameroff
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Stuart Hameroff, MD, (Born in 1947 Buffalo, New York) is an anesthesiologist and professor at the University of Arizona known for his promotion of the scientific study of consciousness, and his speculative theories of the mechanisms of consciousness.
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[edit] Career
Hameroff received his bachelors from the University of Pittsburgh and his medical degree from Hahnemann University Hospital (now part of 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 associate director for the Center for Consciousness Studies, both in 1999, and finally Emeritus professor for Anesthesiology and Psychology in 2003.
[edit] Theories
At the very beginning of his career, while at Hahneman, cancer-related research work resulted in him becoming interested in the part played by microtubules in cell division, and 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[1].
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)[2]. 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 the cytoskeleton components could be the basic units of processing rather than the neurons. The book was primarily concerned with information processing, with consciousness secondary at this stage.
Separately from Hameroff, Roger Penrose had published his first book on consciousness, The Emperor's New Mind[3]. On the basis of Godel'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 modelled as a classical Turing machine type of computer. By contrast, the idea that it could be explained mechanistically 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 criticised by neuroscientists, logicians and philosophers, notably Grush and Churchland (Grush and Churchland, 1995) [4].
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 [1]. Following this collaboration, Penrose published his second consciousness book, Shadows of the Mind[5].
This more developed version of their ideas was also widely attacked, and notably 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 (Tegmark, 2000)[6]. Hameroff and the physicists, Scott Hagan and Jack Tuszynski (Hagan, Hameroff & Tuszynski, 2002)[7] replied to Tegmark arguing that microtubules could be shielded against the environment of the brain. To date, there is no experimental confirmation of these proposed methods of shielding, but Hameroff has proposed tests that could falsify the theory[8].
Over the years since 1994, Hameroff has been active in promoting the Orch-OR model of consciousness through his web site [1], conferences and lectures. He was the lead organizer of the first Tucson consciousness meeting in 1994 that brought together approximately 300 people interested in consciousness for the first time (e.g., David Chalmers, Christof Koch, Bernard Baars, Roger Penrose, Benjamin Libet). This conference is widely regarded as a landmark event within the field of consciousness studies, and by bringing researchers from various disciplines together lead 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 study of consciousness every two years, as well as sponsoring seminars on consciousness theory.
Dr. Hameroff appeared as himself in the documentary film What tнe ♯$*! Do ωΣ (k)πow!? (2004). He also participated in the first Beyond Belief conference, where his theories were sharply criticized by Lawrence Krauss, among others.
[edit] References
- 1. Quantum Consciousness, Stuart Hameroff [1]
- 2. Hameroff,S.(1987) Ultimate Computing Elsevier
- 3. Penrose,R.(1989) The Emperor's New Mind Oxford University Press
- 4. Grush,R.& Churchland,P.(1995) Gap's in Penrose's Toilings Journal of Consciousness Studies, 2(1)pp. 10-29
- 5. Penrose,R.(1994) Shadows of the Mind Oxford University Press
- 6. Tegmark,M. (2000) Importance of quantum coherence in brain processes Physical Reviews E, 61: 4194-4206
- 7. Hagan,S.,Hameroff,S.& Tuszynski, J.(2002) Quantum computation in brain microtubules? Decoherence and biological feasibility Physical Reviews E, 65: 061901
- 8. Hameroff,S.(2006) Consciousness, Neurobiology and Quantum Mechanics In: The Emerging Physics of Consciousness, (Ed.) Tuszynski,J.
[edit] See also
[edit] Further reading
- 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.
