Features of consciousness difficult to understand in terms of conventional neuroscience have evoked application of quantum theory, which describes the fundamental behavior of matter and energy. In this paper we propose that aspects of quantum theory (e.g. quantum coherence) and of a newly proposed physical phenomenon of quantum wave function "self-collapse"(objective reduction: OR -Penrose, 1994) are essential for consciousness, and occur in cytoskeletal microtubules and other structures within each of the brain's neurons. The particular characteristics of microtubules suitable for quantum (...) effects include their crystal-like lattice structure, hollow inner core, organization of cell function and capacity for information processing. We envisage that conformational states of microtubule subunits (tubulins) are coupled to internal quantum events, and cooperatively interact (compute) with other tubulins. We further assume that macroscopic coherent superposition of quantum-coupled tubulin conformational states occurs throughout significant brain volumes and provides the global binding essential to consciousness. We equate the emergence of the microtubule quantum coherence with pre-conscious processing which grows (for up to 500 milliseconds) until the mass-energy difference among the separated states of tubulins reaches a threshold related to quantum gravity. According to the arguments for OR put forth in Penrose (1994), superpositioned states each have their own space-time geometries. When the degree of coherent mass-energy difference leads to sufficient separation of space-time geometry, the system must choose and decay (reduce, collapse) to a single universe state. In this way, a transient superposition of slightly differing space-time geometries persists until an abrupt quantum classical reduction occurs. Unlike the random, "subjective reduction"( SR, or R) of standard quantum theory caused by observation or environmental entanglement, the OR we propose in microtubules is a self-collapse and it results in particular patterns of microtubule-tubulin conformational states that regulate neuronal activities including synaptic functions. (shrink)

Anesthetic gas molecules are recognized to act by van der Waals (London dispersion) forces in hydrophobic pockets of select brain proteins to ablate consciousness. Enigmatic features of consciousness have defied conventional neurophysiological exp lanations and prompted suggestions for supplemental occurrence of macroscopic quantum coherent states and quantum computation in the brain. Are these feasible? During conscious (non-anesthetic) conditions, endogenous Van der Waals London dispersion forces occur among non-polar amino acid groups in hydrophobic pockets of neural proteins and help regulate their (...) conformation/function. London forces are weak instantaneous couplings between pairs of electron induced dipoles (e.g. between adjacent non-polar amino acid groups), and are quantum mechanical effects capable of supporting quantum superposition/computation and macroscopic quantum coherence. Quantum effects mediated by endogenous London forces in hydrophobic pockets of select neural proteins may be necessary for consciousness. The mechanism of anesthetics may be to inhibit (by exogenous London forces) the necessary quantum states. (shrink)

Consciousness defines our existence and reality. But how does the brain generate thoughts and feelings? Most explanations portray the brain as a computer, with nerve cells ("neurons") and their synaptic connections acting as simple switches, or "bits" which interact in complex ways. In this view consciousness is said to "emerge" as a novel property of complex interactions among neurons, as hurricanes and candle flames emerge from complex interactions among gas and dust molecules. However this approach fails to explain why we (...) have feelings and awareness, an "inner life". So we don't know how the brain produces consciousness. (shrink)

Hameroff: I became interested in understanding consciousness as an undergraduate at the University of Pittsburgh in the late 60's. In my third year of medical school at Hahnemann in Philadelphia I did a research elective in professor Ben Kahn's hematology-oncology lab. They were studying various types of malignant blood cells, and I became interested in mitosis-looking under the microscope at normal and abnormal cell division. I became fascinated by centrioles and mitotic spindles pulling apart the chromosomes, doing this little dance, (...) dividing the cytoplasm, establishing the daughter-cell architecture, and beginning differentiation. I remember wondering to myself how these centrioles and mitotic spindles "knew" where to go and what to do. What kind of intelligence was running the show at the cellular level? (shrink)

A recent paper by Rieper, Anders and Vedral (arxiv.org/abs/1006.4053: The Relevance Of Continuous Variable Entanglement In DNA) suggests that quantum entanglement among base pairs in the DNA double helix stabilizes the molecule. A summary of their paper is reported in MIT Technology Review (http://www.technologyreview.com/blog/arxiv/25375/) is below..

The 'Conscious Pilot' is a new model of the neural correlate of consciousness (NCC) consistent with the Orch OR model. The basic idea is that spatiotemporal envelopes of dendritic gamma synchrony move through the brain's neuronal networks. The movement is sideways to neurocomputational flow, occurring via dendritic dendritic gap junction electrical synapses. A conscious pilot moving around an airplane while it flies on auto pilot is used as a metaphor for dendritic synchrony moving through the brain's neurocomputational networks, conveying conscious (...) experience and choice to otherwise non conscious cognitive modes. (shrink)

Stuart Hameroff, M.D., is a doctor of medicine, a professor of anesthesiology and psychology, as well as associate director of the Center for Consciousness Studies at University of Arizona. Through a collaboration with mathematical physicist, Prof Sir Roger Penrose, Prof Hameroff is leading the assault on mainstream thinking about the human mind and how it is that we come to be. Forget space exploration. Forget biotechnology. Forget nanobots. Forget sea monkeys. The final frontier of science is reading this article right (...) now - and there's a very good reason why physicists call it "the hard problem".. (shrink)

As an explanation for order and long range correlations in living systems, Fröhlich (1968; 1970; 1975) proposed certain biomolecules pumped by metabolic processes could exhibit coherent phonon dynamics, perhaps even macroscopic quantum coherence akin to Bose Einstein condensation or lasers. The biomolecular requirements, according to Fröhlich, were: 1) a geometric array or lattice of dipoles constrained in a common voltage gradient, and 2) ample, non coherent biochemical energy. Eligible proposed candidates included membrane proteins, nucleic acids and cytoskeletal microtubules.

Features of consciousness difficult to understand in terms of conventional neuroscience have evoked application of quantum theory, which describes the fundamental behavior of matter and energy. In this paper we propose that aspects of quantum theory (e.g. quantum coherence) and of a newly proposed physical phenomenon of quantum wave function "self-collapse"(objective reduction: OR -Penrose, 1994) are essential for consciousness, and occur in cytoskeletal microtubules and other structures within each of the brain's neurons. The particular characteristics of microtubules suitable for quantum (...) effects include their crystal-like lattice structure, hollow inner core, organization of cell function and capacity for information processing. We envisage that conformational states of microtubule subunits (tubulins) are coupled to internal quantum events, and cooperatively interact (compute) with other tubulins. We further assume that macroscopic coherent superposition of quantum-coupled tubulin conformational states occurs throughout significant brain volumes and provides the global binding essential to consciousness. We equate the emergence of the microtubule quantum coherence with pre-conscious processing which grows (for up to 500 milliseconds) until the mass-energy difference among the separated states of tubulins reaches a threshold related to quantum gravity. According to the arguments for OR put forth in Penrose (1994), superpositioned states each have their own space-time geometries. When the degree of coherent massenergy difference leads to sufficient separation of space-time geometry, the system must choose and decay (reduce, collapse) to a single universe state. In this way, a transient superposition of slightly differing space-time geometries persists until an abrupt quantum classical reduction occurs. Unlike the random, "subjective reduction"(SR, or R) of standard quantum theory caused by observation or environmental entanglement, the OR we propose in microtubules is a self-collapse and it results in particular patterns of microtubule-tubulin conformational states that regulate neuronal activities including synaptic functions. Possibilities and probabilities for post-reduction tubulin states are influenced by factors including attachments of microtubule-associated proteins (MAPs) acting as "nodes"which tune and "orchestrate"the quantum oscillations.. (shrink)

Cognitive decisions are best described by quantum mathematics. Do quantum information devices operate in the brain? What would they look like? Fuss and Navarro () describe quantum lattice registers in which quantum superpositioned pathways interact (compute/integrate) as ‘quantum walks’ akin to Feynman's path integral in a lattice (e.g. the ‘Feynman quantum chessboard’). Simultaneous alternate pathways eventually reduce (collapse), selecting one particular pathway in a cognitive decision, or choice. This paper describes how quantum walks in a Feynman chessboard are conceptually identical (...) to ‘topological qubits’ in brain neuronal microtubules, as described in the Penrose-Hameroff 'Orch OR' theory of consciousness. (shrink)

Come leggere un'antica pergamena senza sro- tolarla? Semplice, basta illuminarla con i raggi X di un sincrotrone (foto). L'analisi al sincro- trone ha svelato i segreti di alcuni manoscritti sigillati del Mar Morto, risalenti al XII secolo, così fragili da non poterli aprire senza rischiare di danneggiarli. Per decifrare un prezioso roto- lo di sottilissima pelle animale, lo strumento lo..

Dynamical activities within living eukaryotic cells are organized by microtubules, main structural components of the cytoskeleton and cylindrical polymers of the protein tubulin. Evidence and theoretical models suggest that states of tubulin may play the role of “bits” in classical microtubule computational automata. The advent of quantum information devices, key roles played by quantum processes in protein dynamics, and coherent ordering in the cell cytoplasm further suggest that microtubules may function as quantum computational devices, and that mesoscopic and macroscopic quantum (...) states are characteristic of living systems. In this paper new results from molecular dynamics simulation based on recently obtained atomic structure of tubulin are presented which provide support for classical and quantum modes of microtubule information processing. (shrink)

Conference Report on ASSC 11, Las Vegas 2007.

As presently implemented, the neuron doctrine (ND) portrays the brain's neurons and chemical synapses as fundamental components in a computer-like switching circuit, supporting a view of brain = mind = computer. However, close examination reveals individual neurons to be far more complex than simple switches, with enormous capacity for intracellular information processing (e.g., in the internal cytoskeleton). Other poorly appreciated factors (gap junctions, apparent randomness, dendritic-dendritic processing, possible quantum computation, the living state) also suggest that the ND grossly oversimplifies neuronal (...) functions. In the quest to understand consciousness, the presently implemented ND may throw out the baby with the bath water. (shrink)

Today we’re talking with Stuart Hameroff, Professor Emeritus at the Departments of Anesthesiology and Psychology, and Director of the Center for Consciousness Studies, at the University of Arizona. Dr Hameroff is best-known for his research on 'quantum consciousness', an alternative model to the accepted view of how consciousness arises. With Sir Roger Penrose, Dr Hameroff has proposed that consciousness arises at the quantum level within structures inside neurons, known as microtubules.