Links to TSC Abstracts 2006-15

2014 Toward a Science of Consciousness, 20th Anniversary, April 21-26, 2014, Tucson, AZ

Co-presenter, workshops and concurrent sessions TSC 2014  TSC 2014 - Book of Abstracts;     

PLENARY 9 (2014) - Quantum Vibrations in Microtubules, 'Orch OR' - 20 Years On, Stuart  Hameroff   -   (Anesthesiology, MD; Psychology; The University of Arizona, Tucson, AZ 2014.  [PL9] [248]    Prevalent views ascribing consciousness to complex computation among integrate-and-fire brain neurons fail to account for memory, binding, the ‘hard problem’, real-time conscious control and (arguably) EEG rhythms. On the contrary, the Penrose-Hameroff theory of ‘orchestrated objective reduction’ (‘Orch OR’), introduced in the mid 1990’s, suggests consciousness and cognition derive from deeper-order, finer scale quantum vibrations in microtubules during integration phases inside integrate-and-fire brain neurons (e.g. within dendrites/soma of pyramidal neurons). According to Orch OR, superpositioned states of microtubule ‘tubulin’ subunits entangle to perform quantum computations according to the Schrodinger equation during neuronal integration phases, these computations terminating by Penrose ‘objective reduction’ (‘OR’) at time t=h/E (h is the Planck-Dirac constant, and E is the gravitational self-energy of superpositioned tubulins).  Penrose OR is a proposed solution to the quantum measurement problem tied to properties of fundamental spacetime geometry (related to quantum gravity), and introduces subjective experience with each OR moment. When occurring in random environmental superpositions (i.e. ‘decoherence’), OR moments are accompanied merely by low intensity, non-cognitive ‘proto-con- scious’ experience. However in brain microtubules, quantum superpositions may be isolated and ‘orchestrated’ (‘Orch’) by memory, synaptic inputs and resonances, allowing functional cognition accompanied by Orch OR moments of full, rich conscious experience and choice. Microtubule tubulin states chosen in each Orch OR event can trigger axonal firings to consciously control behavior and adjust synapses. Orch OR has enormous explanatory power, but has been viewed skeptically, as heat in presumably random biological environments has been assumed to cause ‘decoherence’ of quantum states. But functional quantum activity is observed in photosynthesis, olfaction, bird navigation and -.microtubules.  Using nanotechnology, Bandyopadhyay’s group discovered quantum resonance (gigahertz, megahertz and kilohertz) in single microtubules, and microtubule bundles inside active neurons, with coherence as long as 10-4 secs (10 kilohertz). Microtubule quantum vibrations and Orch OR events e.g. at 10 megahertz (10-7 secs coherence) can resonate across scales, and interfere to generate slower ‘beat frequencies,’ seen as EEG rhythms. Thus Orch OR predicts that EEG derives from faster, finer scale quantum vibrations in microtubules inside neurons, e.g. apical dendrites and soma of cortical pyramidal neurons. As 10-7 secs microtubule coherence is sufficient for Orch OR, and 10-4 secs microtubule coherence has been verified, Orch OR is on firm ground experimentally regarding decoherence. Also, recent evidence indicates anesthetics act in microtubule quantum channels to selectively erase conscious- ness. In conclusion, after 20 years, Orch OR is the most rigorous and successfully tested theory of consciousness ever put forth. Noninvasive therapies aimed at brain microtubule vibrations (e.g. megahertz transcranial ultrasound ‘TUS’) offer potential benefit for a variety of mental and cognitive disorders.


C-13: [284] (2014)  Ultrasound Vibrations Stabilize Microtubules In Vitro Saatviki Gupta, Nandita Gupta; Arun Kumar Gupta; Stuart Hameroff

C-2: [56] (2014)  Deeper-Order Thought (‘DOT’) – An Alternative Higher-Order Thought (‘HOT’) Theory of Consciousness,  Rocco Gennaro, Paavo Pylkkanen, Stuart Hameroff

C-13: [146] (2014)  Low-Intensity Ultrasound Promotes Neurite Outgrowth in Cultured Cortical Neurons Uma Raman, Uma Raman, Sara Parker, Chris Duffield, Sourav Ghosh, Stuart Hameroff

C24: [283] (2014)The Feasibility of Quantum Coherent Effects in Microtubules and Their Potential Role in Neuron Function Travis Craddock, Travis J. A. Craddock; Douglas Friesen; Jonathan Mane; Stuart Hameroff; Jack A. Tuszynski

C7: [115] (2014) Transcranial Ultrasound (TUS) Stimulation at the Scalp Vertex Increases Self-Ratings on a Buddhist-Based Nonattachment Scale Michael Goldstein, Sanguinetti, JL; Tyler, WJ; Hameroff, S; Allen, JJB

C 13: [174] (2014) Transcranial Ultrasound (TUS) Brain Stimulation in Humans: Effects on Mood/Mental States in Three Studies Joseph Sanguinetti, Ezra Smith; William J. Tyler; Stuart Hameroff; John J. B. Allen

2012 Toward a Science of Consciousness, Tucson ARIZONA

The 10th Biennial  - Toward a Science of Consciousness

April 9-14, 2012 TUCSON, ARIZONA

Link to 2012 TSC Abstracts   

2012 - Toward a Science of Consciousness, Tucson, Plenary Abstract: S. Hameroff, Fractal Brain Hierarchy, Consciousness and Orch OR.

Fractal, or scale-free structure and dynamics imply systems with self-similar information patterns occurring across many spatial and temporal scales. Such systems are found widely in nature, including the brain. 1) Structure: neuronal dendrites (and their internal cytoskeleton) have fractal geometry, neurons connect in nested hierarchies of small-world fractal networks [1], and grid cells in layers of entorhinal cortex represent spatial environment at different fractal scales. 2) Mental representation: memory is distributed "holographically"[2], and visual imagery in altered states is often described as fractal. 3) Temporal dynamics: Electrophysiology by He and Raichle [3] and others has shown self-similar dynamic patterns repeating at spatiotemporal scales, e.g. default mode switching (0.1 Hz) and more rapid EEG (10 to 100 Hz), separated by 2 to 3 orders of magnitude. What about smaller, even faster scales? Underlying neuronal and synaptic functions, cytoskeletal microtubules have a series of resonant frequencies, e.g. roughly 10 kilohertz and 10 megahertz [4], and gigahertz and terahertz resonances are proposed. Self-similar dynamics and information processing in these 6 discrete levels (EEG through microtubule resonances), each separated by 2 to 3 orders of magnitude, may comprise a fractal brain hierarchy in which a process supporting consciousness occurs and moves, akin to musical notes moving through different scales and octaves. What process? Penrose-Hameroff Orch OR [5] is the only theory proposing a specific process resulting in consciousness: quantum computations in microtubules, each terminated by quantum state (objective) reduction by E=h/t. E is the degree of quantum superpositioned matter (microtubule tubulin subunits), h is Plancks constant/2 pi, and t the time at which reduction and moments of consciousness occur. Recent demonstration of quantum-like conductance, condensation and resonance in single microtubules at ambient temperature [4] strengthens the biological case for Orch OR immensely. E=h/t, and consciousness, can occur at any layer in a fractal brain hierarchy. At the layer of gamma synchrony EEG at 40 hertz, t equals 25 milliseconds, 40 conscious moments occur per second, and E involves superposition of a billion or so microtubule tubulin subunits (0.0000000001 of total brain tubulins). E=h/t can also occur at deeper levels, with higher frequency, greater experiential intensity, and more microtubule/brain involvement. At 10 kilohertz microtubule resonance, E would involve 0.0000001 of brain tubulins, and at 10 megahertz, E would involve 0.0001 of brain tubulins, nearing brain capacity. Meditation, peak experience and altered states may involve consciousness (by E=h/t) moving to deeper, faster, more intense levels in a fractal brain hierarchy. [1] Bieberich (2002) Biosystems 66(3):145-164; [2] Pribram (1971) Languages of the brain, Prentice-Hall; [3] He and Raichle (2009) TICS, [4] Sahu et al (2012) Nature Materials [5] Penrose and Hameroff (2011) J Cosmology 14

Toward a Science of Consciousness, Stockholm 2011   

Full Program AbstractsTSC2011Stockholm.pdf

Plenary 13 - Abstract 131  - TSC2011

Meyer-Overton Meets Quantum Physics: Consciousness, Memory and Anesthetic Binding in Tubulin Hydrophobic Channels

Stuart Hameroff <> (Anesthesiology, Psych, CCS, Center for Consciousness Studies, University of Arizona, Tucson, AZ), Travis Craddock,    Dept. of Physics, University of Alberta, Edmonton, AB, Canada; Jack Tuszynski, Division of Experimental Oncology, Cross Cancer Institute, Edmonton AB Canada


Anesthetic gases selectively erase conscious awareness and memory, sparing non-conscious brain activities. At the turn of the 20th century, Meyer and Overton found anesthetic potency correlates with solubility/binding in a non-polar, hydrophobic environment, subsequently shown to be hydrophobic pockets within proteins (Franks and Lieb, 1984), including 70 receptors, ion channels and tubulin in cytoskeletal microtubules (Eckenhoff et al, 2002). Anesthetic gases bind in hydrophobic regions by quantum London forces, electron cloud dipole couplings with non-polar amino acid residues, e.g. phenylalanine and tryptophan. Theories suggest anesthetic quantum actions in protein hydrophobic regions (Hameroff, 2006), and quantum computations in microtubules supporting consciousness (Hameroff and Penrose, 1996). Evidence for functional quantum effects in warm biology include ion channels and microtubules (e.g. megahertz coherence, lossless conductance through helical lattice pathways, Bandyopadhyay, 2011). Quantum processes in microtubule hydrophobic regions are potential sites for consciousness and anesthetic action.

We used molecular modeling of tubulin to identify tryptophan, phenylalanine and anesthetic binding sites, and calculated anesthetic-tubulin binding energies and affinities. Results Within tubulin, 8 tryptophans and 32 phenylalanines cluster and align (< 2 nanometer separation) along tubulin-tubulin helical pathways. Predictive anesthetic binding energies are between -2.54 and -3.12 kcal/mol, corresponding to dissociation constants (binding affinity) between 6 and 16 millimolar. Anesthetics bind at 5 putative sites, e.g. within 6 angstroms (0.6 nanometer) of an aligned tryptophan with a binding energy of -2.74 kcal/mol (11.7 millimolar). Discussion Anesthetic-tubulin binding is 10 to 100 times weaker than anesthetic binding to other neuronal proteins, e.g. GABAa receptors. However there are 100 times more tubulins than GABAa receptors per neuron. Intra-tubulin hydrophobic channels match microtubule lattice helical pathways, and may account for lossless conductance (Bandyopadhyay, 2011) and topological quantum computing implicated in consciousness and memory (Hameroff et al, 2002; 2010). Microtubule hydrophobic channels (possibly quantum entangled with GABAa receptors and other neuronal proteins) are viable candidates for consciousness, memory and anesthetic action. References Bandyopadhyay A (2011) TSC abstracts; Eckenhoff et al (2002) J Pharm Exp Ther 300:172-9; Franks and Lieb (1984) Nature 310:599-610; Hameroff S, Penrose R (1996) J Consciousness Studies 3(1)36-53; Hameroff et al (2002) Biosystems 64:149-162; Hameroff S (2006) Anesthesiology 105:400-412; Hameroff et al (2010) J Integrative Neuroscience 9(3)253-267 PL13


2010 - Toward a Science of Consciousness, Tucson, Plenary Abstract:  S. Hameroff, Clarifying the Qubit...

Link to 2010 TSC Abstracts

Clarifying the Qubit - Response to recent attack against Penrose-Hameroff
INTRODUCTION The Penrose-Hameroff orchestrated objective reduction (Orch OR) theory postulates quantum computation in microtubules (MTs) inside brain neurons as an explanation for consciousness. Orch OR has been attacked by McKemmish et al (Phys Rev E, 80:021912, 2009) who assert Orch OR in MTs is biologically unfeasible, and unsalvageable. BACKGROUND MTs are cylindrical lattices of peanut-shaped tubulin proteins. The basic Orch OR idea is that discrete MT tubulin states act as information bits and quantum bits (qubits) in MT computers inside brain neurons. Orch OR suggests MT tubulin qubits switch coherently and compute by entanglement with other tubulins, performing quantum computations which self-collapse by Penrose objective reduction. SPECIFIC CRITICISM OF ORCH OR McKemmish et al focus on switching between discrete tubulin bit and qubit states, describing tubulins flexing between two conformations (shortening by ~3%) depending on GTP hydrolysis to GDP. They assert such GTP-dependent switching is involved in MT treadmilling in which MTs polymerize at one end and depolymerize at the other, finding such conformational switching too slow for Orch OR. RESPONSES IN DEFENSE OF ORCH OR 1) Neuronal MTs have specific caps (e.g. STOP proteins) which stabilize MTs, preventing depolymerization and treadmilling (J Cell Biology 142:167, 1998). Hence the McKemmish et al scenario does not generally apply to MTs in brain neurons. 2) Contrary to McKemmish et al assertions, tubulin switching in Orch OR is driven by quantum electronic London forces in hydrophobic pockets, non-polar regions formed by aromatic amino acid rings and other non-polar groups within proteins, and sites of anesthetic gas binding and action. Each tubulin has over twenty hydrophobic pockets, including phosphorylation sites for GTP, MAPs and CaMKII. Thus GTP hydrolysis is but one factor regulating tubulin states and coherence, all potentially mediated through collective London forces in quantum hydrophobic pockets. 3) McKemmish et al assume that protein conformation stems exclusively from atomic nuclear motions which then affect delocalizable electrons. This is the bus turning the steering wheel. The rationale for quantum devices is for low energy quantum states to be amplified to regulate conformational (nuclear) motions. Thus quantum events (including conscious events) can exert causal efficacy in the classical world. McKemmish et al completely miss the point. 4) Experimental evidence shows coherent dipole excitations in MTs at 8.085 megahertz (Pokorny, Bioelectrochemistry, 63:321, 2004). McKemmish et al validate MT megahertz coherence, but claim it cannot help Orch OR because energy required to drive coherence of tubulin conformational flexion states is too high. But Orch OR requires superposition separation of only diameters of atomic nuclei, and asserts low energy electronic quantum London forces govern tubulin states. Megahertz coherence in MTs strongly supports Orch OR. 5) McKemmish et al assertions that Orch OR is untenable and unsalvageable are based on misrepresentations and misconceptions. Their funding (from Artificial Intelligence) and statements such that denial of Orch OR gives hope to the vision that digital computing could achieve truly significant levels of artificial intelligence shows their attack is not science but a political hit job.  


2009 Hong Kong:   Stuart Hameroff, Quantum Perspective



2008  -  Toward a Science of Consciousness - Tucson Conference

Link to 2008 TSC Abstracts

Abstract 184 -  S. Hameroff, The ‘conscious pilot’: Synchronized dendritic webs move through brain neurocomputational networks to mediate consciousness.   Chalmers’ ‘easy problems’ include the brain’s non-conscious abilities to discriminate and react to stimuli, integrate information, focus attention and control behavior, also expressed as ‘zombie’, or ‘auto-pilot’ modes. Chalmers’ ‘hard problem’ is the question of how the brain produces subjective conscious experience which, unlike non-conscious auto-pilot modes, is not amenable to conventional neurocomputational explanations. ‘Easy problem’ auto-pilot modes and ‘hard problem’conscious experience are not mutually exclusive. At times, auto-pilot modes become driven by, or accompanied by, conscious experience. For example we often perform complex behaviors while daydreaming, on auto-pilot with consciousness somewhere else. But when a horn sounds or a light flashes, we consciously perceive the scene and assume conscious control. Rather than distinguishing between auto-pilot modes and consciousness, the essential distinction may be between auto-pilot modes which are, or are not, accompanied by some added fleeting feature which conveys conscious experience and choices – the ‘conscious pilot’. Consider an airplane cruising on auto-pilot. The conscious pilot is present, but not directly in control – perhaps he/she is reading a magazine,sleeping and dreaming, or chatting in themain cabin. Suddenly turbulence occurs, or an alarm sounds. The conscious pilot ‘tunes in and takes over’, directing his/her attention to the cockpit view and instrument readings, assuming control of the plane. When the situation is resolved the auto-pilot resumes monitoring and control, and the conscious pilot visits with the flight attendant. In the metaphor, the auto-pilot is the plane’s on-board flight computer and instruments. In the brain, the non-conscious auto-pilot is readily explained by neurocomputation: neuronal dendrites receive and integrate spike-mediated synaptic inputs, and when threshold is met, axonal spikes are fired as outputs. Discrete information states (‘bits’) are conveyed by axonal spikes/firings. What about conscious modes? The best measurable correlate of consciousness is gamma synchrony EEG (coherent 30 to 90 Hz field potential oscillations), occurring in various brain regions which change over time and move through the brain, or globally, e.g. cortical or thalamo-cortical gamma synchrony. Themobile synchrony correlating with consciousness is produced not by axonal spikes/firings,but via networks of neighboring neuronal dendrites connected ‘sideways’ by gap junctions (‘dendritic webs’). In computer terms, dendritic webs are laterally-connected input/integration layers embedded in feed-forward and feed-back networks. Gap junction openings and closings evolve dynamical dendritic web topologies moving throughout axonal-dendritic networks accompanied by gamma synchrony and consciousness. (Within cytoplasmic interiors of dendritic webs, the Penrose-Hameroff Orch OR model proposes quantum computations in microtubules underlie consciousness.) Gamma synchronized dendritic webs are perfectly suited to function as the brain’s ‘conscious pilot’, moving throughout neurocomputational axonal-dendritic networks, able to tune in and take over from non-conscious auto-pilot modes. PL8



2006 Tucson Toward a Science of Consciousness

Abstract 89 - The neuron doctrine, “hyper-neurons” and the NCC  Stuart Hameroff <> (Center for Consciousness Studies, University of Arizona, Tucson, Arizona)

The NCC is attributed to networks of discrete neurons, each with multiple synaptic/dendritic inputs and “all-or-none” digital axonal outputs. Stemming from Cajal’s century-old “neuron doctrine”, discrete neuronal input/output functions also support brain/computer analogies. Because all-or-none axonal output “spikes” are readily quantified and correlate with behavior, spikes are often equated with the NCC. However evidence casts doubt on both the neuron doctrine and spike-based NCC(1): 1) Dendrites do more than summate EPSPs/IPSPs to threshold. Highly branched dendrites contain mosaics of different receptors whose spatial distribution (organized by internal cytoskeleton/previous activity) is a complex determinant of neuronal function. Dendrites perform local complex logic, boost signals and modulate axon hillock spike threshold. In many neurons, spikes travel “backward”, and dendrites can initiate their own spikes. Triggering axonal spikes is not necessarily the raison d’etre of dendrites. 2) Electrophysiological and metabolic NCCs correlate with dendritic activity. The best electrophysiological NCC, gamma synchrony EEG is produced by local field potentials (LFPs) from dendritic graded potentials, and coordinated by cortical interneurons linked by gap junctions. Spikes are not gamma synchronized. Some cortical neurons have no axons, and extensive dendritic activity below spike threshold (historically considered noise) oscillates coherently across wide brain regions.(2) The fMRI BOLD signal also correlates with dendritic LFPs more than with spikes. 3) Gap junction “hyper-neurons” best represent the NCC. Gap junctions are windows between adjacent cells which electrically couple membranes and provide continuous internal cytoplasm. Gap junctions couple dendrites with other neurons’ dendrites, axons and glia, forming syncytial “hyper-neurons”(3) which oscillate coherently in the gamma EEG range and extend widely through cortex.(4) Gap junctions open, close, form and disappear, dependent on activity and cytoskeletal processes. Thus hyper-neurons are plastic and adaptive (e.g. “Hebbian”). 4) Anesthetics ablate consciousness via post-synaptic dendrites. General anesthetics reversibly erase consciousness with relative selectivity, sparing other brain activities including sub-gamma EEG, evoked potentials, and autonomic regulation. Anesthetics act on post-synaptic ligand gated ion channels, metabotropic receptors, dendritic spine actin, second messengers and cytoskeletal structures. General anesthetics have little or no effects on spikes. 5) Dendritic cytoskeleton is uniquely configured to process information. Unlike those in axons or non-neuronal cells, dendritic microtubules are discontinuous and of mixed polarity, connected by specialized microtubule-associated proteins (MAPs) in local processing networks which regulate cognitive functions. Shape and dynamics of actin-filled dendritic spines have also been linked to cognition and consciousness (e.g. Crick). And metabotropic membrane receptors send signals into the dendritic cytoskeleton. For many years Sir John Eccles, Karl Pribram and others have argued that consciousness arises from dendrites, with axons providing input to, and output from, conscious processes in dendrites. Gap junction hyper-neurons fulfill this argument and are consistent with electrophysiology, fMRI, anesthetic mechanisms and all known neuroscientific data. It is logical to conclude that hyper-neurons are the NCC. 1. Bullock et al (2005) Science 310: 791 2. Woolf NJ Hameroff S (2001) TICS 5:472 3. Ferster D (1996) Science 272:1812. 4. Amitai, Y et al. (2002) The Journal of Neuroscience 22(10): 4142.   C10



2009 - EvoStar 

Ninth European Conference on Evolutionary Computation in Combinatorial Optimization, 15-17 April 2009  Eberhard Karls Universität,  Tübingen, Germany

Opening Talk: The ‘conscious pilot’ – Dendritic synchrony moves through the brain (like a computer worm) to mediate consciousness.
The brain is viewed as a computer in which sensory processing, control of behavior and other cognitive functions emerge from ‘neurocomputation’ in parallel networks of perceptron-like neurons. In each neuron, dendrites receive and integrate synaptic inputs to a threshold for axonal firing as output – ‘integrate-and-fire’. Neurocomputation in axonal-dendritic synaptic networks successfully accounts for non-conscious (auto-pilot) cognitive brain functions. When cognitive functions are accompanied by consciousness, neurocomputation is accompanied by 30 to 90 Hz gamma synchrony EEG. Gamma synchrony derives primarily from neuronal groups linked by dendritic-dendritic gap junctions, forming transient syncytia (‘dendritic webs’) in input/integration layers oriented sideways to axonal-dendritic neurocomputational flow. As gap junctions open and close, a gamma-synchronized dendritic web can rapidly change topology, evolve and move through the brain (like a benevolent computer worm might move through computer circuits) as a spatiotemporal envelope performing collective integration and volitional choices correlating with consciousness. The ‘conscious pilot’ is a metaphorical description for a mobile, gamma-synchronized dendritic web as vehicle for a conscious agent/pilot which experiences and assumes control of otherwise non-conscious auto-pilot neurocomputation. Intra-neuronal aspects of consciousness involving e.g. quantum computation in cytoskeletal microtubules will also be discussed, as will the evolution and place of consciousness in the universe.

Abstract p.39 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. Lecture Several Powerpoint lectures and an abstract are below the images.


INSERT POWER POINT: tuebingen 33,472 KB

See Website pages on Conscious Pilot:


Center for Consciousness Studies


Center for Consciousness Studies



Why anesthetic mechanism research has failed, and how to fix it [pdf]