Stuart Hameroff
Encyclopedia
Stuart Hameroff is an anesthesiologist
and professor at the University of Arizona
known for his scientific studies of consciousness
.
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 associate director for the Center for Consciousness Studies, both in 1999, and finally Emeritus professor for Anesthesiology and Psychology in 2003.
s 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[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 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, 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 criticized 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 studies (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 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.
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.
Anesthesiologist
An anesthesiologist or anaesthetist is a physician trained in anesthesia and peri-operative medicine....
and professor at the University of Arizona
University of Arizona
The University of Arizona is a land-grant and space-grant public institution of higher education and research located in Tucson, Arizona, United States. The University of Arizona was the first university in the state of Arizona, founded in 1885...
known for his scientific studies of consciousness
Consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
.
Career
Hameroff received his BSBachelor of Science
A Bachelor of Science is an undergraduate academic degree awarded for completed courses that generally last three to five years .-Australia:In Australia, the BSc is a 3 year degree, offered from 1st year on...
degree from the University of Pittsburgh
University of Pittsburgh
The University of Pittsburgh, commonly referred to as Pitt, is a state-related research university located in Pittsburgh, Pennsylvania, United States. Founded as Pittsburgh Academy in 1787 on what was then the American frontier, Pitt is one of the oldest continuously chartered institutions of...
and his MD
Doctor of Medicine
Doctor of Medicine is a doctoral degree for physicians. The degree is granted by medical schools...
degree from Hahnemann University Hospital, where he studied before it became part of the Drexel University College of Medicine
Drexel University College of Medicine
Drexel University College of Medicine is the medical school of Drexel University. The medical school has the nation's largest enrollment for a private medical school, and represents the consolidation of two medical schools: the nation's first medical school for women and the first U.S. college of...
. 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.
Theories
At the very beginning of Dr. Hameroff's career, while he was at Hahnemann, cancer-related research work piqued his interest in the part played by microtubuleMicrotubule
Microtubules are a component of the cytoskeleton. These rope-like polymers of tubulin can grow as long as 25 micrometers and are highly dynamic. The outer diameter of microtubule is about 25 nm. Microtubules are important for maintaining cell structure, providing platforms for intracellular...
s 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[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
Cytoskeleton
The cytoskeleton is a cellular "scaffolding" or "skeleton" contained within a cell's cytoplasm and is made out of protein. The cytoskeleton is present in all cells; it was once thought to be unique to eukaryotes, but recent research has identified the prokaryotic 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, Roger Penrose
Roger Penrose
Sir Roger Penrose OM FRS is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College...
had published his first book on consciousness, The Emperor's New Mind
The Emperor's New Mind
The Emperor's New Mind: Concerning Computers, Minds and The Laws of Physics is a 1989 book by mathematical physicist Sir Roger Penrose.Penrose presents the argument that human consciousness is non-algorithmic, and thus is not capable of being modeled by a conventional Turing machine-type of digital...
[3]. On the basis of Godel's incompleteness theorems
Gödel's incompleteness theorems
Gödel's incompleteness theorems are two theorems of mathematical logic that establish inherent limitations of all but the most trivial axiomatic systems capable of doing arithmetic. The theorems, proven by Kurt Gödel in 1931, are important both in mathematical logic and in the philosophy of...
, 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 criticized by neuroscientists, logicians and philosophers, notably Grush and Churchland
Patricia Churchland
Patricia Smith Churchland is a Canadian-American philosopher noted for her contributions to neurophilosophy and the philosophy of mind. She has been a Professor at the University of California, San Diego since 1984...
(Grush and Churchland, 1995) [4].
Hameroff was inspired by Penrose's book to contact Penrose regarding his own theories about the mechanism of anesthesia
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
, 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
Orch-OR
Orch-OR is a theory of consciousness, which is the joint work of theoretical physicist Sir Roger Penrose and anesthesiologist Stuart Hameroff. Mainstream theories assume that consciousness emerges from the brain, and focus particularly on complex computation at synapses that allow communication...
) model of consciousness [1]. Following this collaboration, Penrose published his second consciousness book, Shadows of the Mind
Shadows of the Mind
Shadows of the Mind: A Search for the Missing Science of Consciousness is a 1994 book by mathematical physicist Roger Penrose, and serves as a followup to his 1989 book The Emperor's New Mind: Concerning Computers, Minds and The Laws of Physics....
[5].
This more developed version of their ideas was also widely attacked, and notably by the physicist, Max Tegmark
Max Tegmark
Max Tegmark is a Swedish-American cosmologist. Tegmark is a professor at the Massachusetts Institute of Technology and belongs to the scientific directorate of the Foundational Questions Institute.-Early life:...
, 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 studies (e.g., David Chalmers
David Chalmers
David John Chalmers is an Australian philosopher specializing in the area of philosophy of mind and philosophy of language, whose recent work concerns verbal disputes. He is Professor of Philosophy and Director of the Centre for Consciousness at the Australian National University...
, Christof Koch
Christof Koch
Christof Koch is an American neuroscientist working on the neural basis of consciousness. He is the Lois and Victor Troendle Professor of Cognitive and Behavioral Biology at California Institute of Technology, where he has been since 1986...
, Bernard Baars
Bernard Baars
Bernard J. Baars is a former Senior Fellow in Theoretical Neurobiology at The Neurosciences Institute in La Jolla, CA., and is currently an Affiliated Fellow there. He is best known as the originator of the global workspace theory, a theory of human cognitive architecture and consciousness...
, Roger Penrose
Roger Penrose
Sir Roger Penrose OM FRS is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College...
, Benjamin Libet
Benjamin Libet
Benjamin Libet April 12, 1916, Chicago, Illinois - July 23, 2007, Davis, California) was a pioneering scientist in the field of human consciousness. Libet was a researcher in the physiology department of the University of California, San Francisco...
). This 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
Association for the Scientific Study of Consciousness
The Association for the Scientific Study of Consciousness is a professional membership organization that aims to encourage research on consciousness in cognitive science, neuroscience, philosophy, and other relevant disciplines in the sciences and humanities, directed toward understanding the...
, and more directly in the creation of the Center for Consciousness Studies at the University of Arizona
University of Arizona
The University of Arizona is a land-grant and space-grant public institution of higher education and research located in Tucson, Arizona, United States. The University of Arizona was the first university in the state of Arizona, founded in 1885...
, 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.
Hameroff appeared as himself in the documentary film What tнe ♯$*! Do ωΣ (k)πow!? (2004). He also participated in the first Beyond Belief
Beyond Belief: Science, Religion, Reason and Survival
Beyond Belief: Science, Religion, Reason and Survival, the first of The Science Network's annual Beyond Belief symposia, held from November 5 to November 7, 2006, was described by the New York Times, as "a free-for-all on science and religion," which seemed at times like "the founding convention...
conference, where his theories were sharply criticized by Lawrence Krauss, among others.
Further reading
- Stuart Hameroff with Conrad Schneiker, Ultimate Computing: Biomolecular Consciousness and NanotechnologyNanotechnologyNanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres...
, 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.