Clarifying the Tubulin bit/qubit - Defending the Penrose-Hameroff Orch OR Model (Quantum Biology)
Google Workshop on Quantum Biology
Clarifying the tubulin bit/qubit - Defending the Penrose-Hameroff Orch OR Model of Quantum Computation in Microtubules
Presented by Stuart Hameroff
October 22, 2010
The Penrose-Hameroff theory of orchestrated objective reduction (Orch OR) postulates quantum computation in microtubules inside brain neurons underlying consciousness. Specifically, Orch OR proposes that tubulin proteins comprising microtubule cylindrical lattices function as 'bits' -- switching between alternative states (e.g. of 1 or 0), as well as quantum bits or 'qubits' (existing transiently as quantum superposition of both 1 AND 0). Despite increasing evidence for functional quantum effects in warm biological systems, Orch OR has been recently criticized, e.g. in Phys Rev E by McKemmish et al (2009), who claim the nature and energetic requirements for switching of tubulin bits and qubits in microtubules make Orch OR biologically unfeasible and unsalvageable irrespective of any conceivable modification. Here we show that McKemmish et al misrepresent tubulin bit switching as proposed in Orch OR, and merely disprove their own misrepresentation. Specifically we address their allegations regarding regulation of tubulin switching by 1) van der Waals London forces, 2) GTP hydrolysis and 3) Fröhlich coherence, and show how they are wrong on all counts. We clarify certain aspects of tubulin with regard to potential bit/qubit function, and describe topological tubulin qubits specific to microtubule geometry with particular reference to helical ballistic conductance discovered by Bandyopadhyay. Orch OR remains viable and testable.
About the speaker: Stuart Hameroff MD is Professor of Anesthesiology and Psychology, and Director of the Center for Consciousness Studies at the University of Arizona Medical Center in Tucson, Arizona. A clinical anesthesiologist, Hameroff's academic research for 35 years has focused on how the brain produces consciousness, and how anesthetic gases selectively erase it. In medical school in the early 1970s Hameroff became interested in microtubules and developed a theory of microtubules as self-organizing molecular automata supporting consciousness and other functions inside brain neurons. In 1987 he authored Ultimate Computing: Biomolecular Consciousness and Nanotechnology, a survey of microtubule capabilities and potentials. In the early 1990s Hameroff teamed with British physicist Sir Roger Penrose to develop the controversial Penrose-Hameroff "Orch OR" model of consciousness based on microtubule quantum computation, a theory bolstered by recent discoveries of warm quantum coherence in biology. Hameroff also organizes the conference series Toward a Science of Consciousness, has written and co-edited 4 other books and numerous research articles, and recently developed the 'conscious pilot', a theory supportive of Orch OR involving spatiotemporal envelopes of dendritic synchrony moving through the brain as a conscious agent. Hameroff's research website is http://www.quantumconsciousness.org.