Quantum mind

The quantum mind or quantum consciousness is a protoscientific hypothesis that posits a connection between consciousness, neurobiology and quantum mechanics. There are many blank areas in understanding the brain dynamics and especially how it gives rise to consciousness. The hypothesis claims that quantum mechanics is capable of explaining conscious experience.

Introduction
The nature of consciousness and its place in the universe remain unknown. Classical models view consciousness as computation among the brain's neurons but as yet has failed to describe an exact mechanism. Quantum processes in the brain have been invoked as explanations for consciousness and its enigmatic features. Some theories have been subjected to experimental tests and evidence indicating that quantum non-locality is occurring in conscious and subconscious brain functions has been claimed, however these results have not gained wide acceptance.

Supporters argue that the brain can no longer be seen as simply a vast piece of organic clockwork, but as a subtle device amplifying quantum events and that quantum computation would surely be advantageous from an evolutionary perspective, and biology has had 4 billion years to solve the decoherence problem and evolve quantum mechanisms.

The main argumentative line can be summed up as follows: Human thought, based on the Gödel result, is sound, yet non-algorithmic, and the human thinker is aware of or conscious of the contents of these thoughts. The only recognized instances of non-algorithmic processes in the universe, based on accepted physical theories are purely random or the reduction of the quantum mechanical state vector. Randomness is not promising as the source of the non-algorithmicity needed to account for consciousness, therefore certain quantum mechanical phenomena must be responsible.

Critics deride this comparison as a mere "minimization of mysteries," ( A term coined by David Chalmers, the idea that since quantum and consciousness are both mysteries, they must be related.) and point out that the brain is too warm for quantum computation, which in the technological realm requires extreme cold to avoid "decoherence" (i.e. the loss of seemingly delicate quantum states by interaction with the environment.)

Some modern "New Age" writers have used the theory to support the belief that the human mind commands special powers - psychic forces - that transcend the material universe.

Vibrations of the aether
A relation between consciousness and quantum effects has been pondered for nearly a century, and even before that Newton himself had proposed that vibrations of the aether might be excited by, and in turn, excite the brain. This speculation forms the conceptual foundation for the modern study of quantum consciousness.

Modulating quantum jumps
The first modern pioneer of this field was biologist Alfred Lotka, who in 1924, proposed that the mind controls the brain by modulating the quantum jumps that would otherwise lead to a completely random existence. However, the first detailed quantum model of consciousness was by a physicist, Evan Walker. In 1970 he proposed a synaptic tunneling model in which electrons can "tunnel" between adjacent neurons, thereby creating a virtual neural network overlapping the real one. It is this virtual nervous system that for Walker produces consciousness and that it can direct the behavior of the real nervous system. In short the real nervous system operates by means of synaptic messages while the virtual one operates by means of quantum tunneling.

Bose-Einstein condensates
In 1989 the British psychiatrist Ian Marshall examined similarities between the holistic properties of Bose-Einstein condensates and those of consciousness. In 1968 the British physicist Herbert Fröhlich had suggested that condensation similar to Bose-Einstein can be achieved in Nature by biological organisms which are in a non-equilibrium state. In Marshall's hypothesis, the brain contains a Frölich-style condensate, and, whenever the condensate is excited by an electrical field, conscious experience occurs. Marshall theory contends that the brain would maintain its dynamical coherence due precisely to the properties of such a condensate.

Synaptic quantum uncertainty
John Carew Eccles speculated in 1986 that the synapses in the cortex may respond in a probabilistic manner to neural excitation; a probability that, given the small dimensions of synapses, could be governed by quantum uncertainty.

Consciousness as the observer
The philosopher Michael Lockwood noted that special relativity implies that mental states must be physical states. He argued that sensations must be intrinsic attributes of physical brain states. Thus in quantum terms each sensation corresponds to an observable event in the brain; this makes the observer, in quantum mechanics, conscious of the physical world.

Conscious matter
Nick Herbert, a physicist, has been even more specific on the similarities between Quantum Theory and consciousness. Herbert thinks that consciousness is a pervasive process in nature and that it is as fundamental a component of the universe as elementary particles and forces. James Culbertson, a pioneer of research on robots, has even speculated that consciousness may be a relativistic feature of space-time. In his opinion, too, consciousness permeates all of nature, so that every object has a degree of consciousness. This view is referred to as Conscious Matter.

A tripartite model
The American physicist Henry Stapp's model of consciousness is tripartite in that each event is driven by three quantum processes operating in concert. The first a mechanical, deterministic process that predicts the state of the system given its state at a given time. The second is conscious choice. In the formal Quantum Theory it is implied that something can be known only when Nature is asked a question. This implies,the third that in turn consciousness has a degree of control over Nature because each time something is learned there is a change in the state of the universe, which directly corresponds to a change in the state of the brain. In Q.M. terms; there occurs a reduction of the wave function compatible with the fact that something has been learned.

Quantum solitons
Stuart Hameroff, A. Nip, M. Porter and J. A. Tuszynski have claimed that the neuronal cytoskeletons are primary residence for consciousness and that the specific protein organization and functions help the quantum mind control overall brain dynamics according to the received electromagnetic input. He proposes that when the microtubules strongly interact with the local electromagnetic field solitons could be generated and could propagate along intraprotein conduction aromatic acid pathways. Thus quantum soliton creation could be induced in microtubules via interaction with the local electromagnetic field. See Quantum brain dynamics

Thought as a hologram
Many properties of the brain are the same properties that are commonly associated with holograms: memory is distributed in the brain and memories do not disappear all of a sudden, but slowly fade away. To psychologist Karl Pribram, a sensory perception is transformed in a "brain wave", a pattern of electromagnetical activation that propagates through the brain just like the wavefront in a liquid. The various waves that travel through the brain can interfere. The interference of existing waves (a memory), and a fresh perceptual wave (sensory input) generates a structure that resembles a hologram that is experienced as thought. Pribram refers to this as Holonomic brain theory

A string theory model
A string theory model was developed by D. Nanopoulos in 1996 that was further refined into a QED-Cavity model by N. Mavromatos in 2000 suggesting dissipationless energy transfer and biological quantum teleportation.

Quantum neurophysics
The Heisenberg and Von Neumann tradition has always viewed the brain as a quantum measuring device but others, claim that brain substrates can hold second-order quantum fields, which cannot be treated as mere measuring devices. This is the position of Kunio Yasue, a Japanese physicist who has developed quantum neurophysics. Yasue presents the brain as a macroscopic quantum system wherein the classical world can originate from quantum processes. Not a connectionist, the fact that neurons are organized inside the brain is not relevant to Yasue. See Quantum brain dynamics for references.

Space-time theories of consciousness
Alex Green has developed an empirical theory of phenomenal consciousness that proposes that conscious experience can be described as a five-dimensional manifold. As in Broad's hypothesis, space-time can contain vectors of zero length between two points in space and time because of an imaginary time coordinate. A 3D volume of brain activity over a short period of time would have the time extended geometric form of a conscious observation in 5D. Green considers imaginary time to be incompatible with the modern physical description of the world, and proposes that the imaginary time coordinate is a property of the observer and unobserved things (things governed by quantum mechanics), whereas the real time of general relativity is a property of observed things.

Quantum spin-mediated consciousness
The spin-mediated consciousness theory, initially proposed by biophysicist Huping Hu with his collaborator Maoxin Wu is a theory that says quantum spin is the seat of consciousness and the linchpin between mind and the brain, that is, spin is the mind-pixel. According to this theory, Quantum consciousness is intrinsically connected to the spin process and emerges from the self-referential collapses of spin states and the unity of mind is achieved by entanglement of these mind-pixels.

The Orch OR model
The theory espoused by Roger Penrose and Stuart Hameroff is Quantum-gravitational Consciousness, and currently it is one of the best developed and the most popular. The Orch OR model presumes that the microtubule network within neurons acts like a quantum computer. The tubulins are in superposition and the collapse of the wave function is driven by the quantum gravity. Penrose and Hameroff believe that conscious information is encoded in space-time geometry at the fundamental Planck scale and that a self-organizing Planck-scale process results in awareness.

M-theory
This approach by B. Flanagan builds on his work in mind/brain identity theory, positing an identity between photonic fields and their concomitant perceptual fields. Pointing to the symmetries and phase relations observed with color and sound, this work was extended to include considerations from Kaluza-Klein theory, gauge theory, fiber bundle theory, string theory, Chern-Simons theory and M-theory.

Quantum mysticism
The implications of Quantum mind theories have not been missed by believers of the paranormal, anxious for scientific justification of their beliefs. Some have claimed that quantum mechanics has eliminated the separation between mind, body and the world. The term "quantum consciousness" now shows up in the popular literature in connection with astrology, homeopathy, ghosts, angels, precognition, telepathy, alien abduction, acupuncture, and even how to achieve multiple orgasms. The writings of Fritjof Capra and Deepak Chopra have been instrumental in popularizing the view that there exists a connection between mysticism and quantum mechanics.

Criticisms
Broadly, the arguments against the possibility are:

First, comparatively large and high temperature items like neurons just do not exist in persisting states of linear superposition capable of exhibiting interference effects, and quantum mechanics offers no reason to think they should. All brain scale systems spend their time in well defined classical states; their behavior, even after interaction with thoroughly quantum systems like a decaying atoms, can be described perfectly well with ordinary probability calculus. It turns out that effective classicality extends, under almost all conditions, far below the neural level to that of medium-sized molecules.

Secondly, the truth of decoherence is that, regardless of whether there are any conscious observers around or not, objects which would be expected to behave in an essentially classical manner, do exactly that. Interaction between objects and their environments, both external and internal, does the job of 'observation' erroneously accorded only to conscious observers, effecting a process which is experimentally indistinguishable from state vector reduction.

Thirdly, none of the theories explains how the activity of single synapses enters the dynamics of neural assemblies, and they leave mental causation of quantum processes as a mere claim. Thus they are essentially unsatisfactory with regard to a sound formal basis and concrete empirical scenarios and lack compelling argument or evidence that requires that quantum mechanics play a central role in human consciousness.

Pseudonomenalism
Quantum theories of mind are among the few classes of theories acceptable in the philosophical stances of pseudonomenalism and mind/brain identity theory.

Many-minds interpretation
There is another type of quantum theory of mind called the many-minds interpretation that is invoked as a conservative version of the many-worlds interpretation of quantum theory and does not involve collapse of the QM wave function.

Consciousness causes collapse
Consciousness causes collapse is the speculative theory that observation by a conscious observer is responsible for the wavefunction collapse and that the process of measurement in quantum mechanics is consciousness itself.