The quantum mind or quantum consciousness is a group of hypotheses proposing that
classical mechanics
Classical mechanics is a physical theory describing the motion of macroscopic objects, from projectiles to parts of machinery, and astronomical objects, such as spacecraft, planets, stars, and galaxies. For objects governed by classi ...
alone cannot explain
consciousness
Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scien ...
,
positing instead that
quantum-mechanical
Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, qu ...
phenomena, such as
entanglement and
superposition, may play an important part in the brain's function and could explain critical aspects of consciousness. These scientific hypotheses are as yet untested, and can overlap with
quantum mysticism
Quantum mysticism, sometimes referred pejoratively to as quantum quackery or quantum woo, is a set of metaphysical beliefs and associated practices that seek to relate consciousness, intelligence, spirituality, or mystical worldviews to the ideas ...
.
History
Eugene Wigner
Eugene Paul "E. P." Wigner ( hu, Wigner Jenő Pál, ; November 17, 1902 – January 1, 1995) was a Hungarian-American theoretical physicist who also contributed to mathematical physics. He received the Nobel Prize in Physics in 1963 "for his co ...
developed the idea that quantum mechanics has something to do with the workings of the mind.
He proposed that the
wave function collapse
In quantum mechanics, wave function collapse occurs when a wave function—initially in a quantum superposition, superposition of several eigenstates—reduces to a single eigenstate due to interaction with the external world. This interaction is ...
s due to its interaction with consciousness.
Freeman Dyson
Freeman John Dyson (15 December 1923 – 28 February 2020) was an English-American theoretical physicist and mathematician known for his works in quantum field theory, astrophysics, random matrices, mathematical formulation of quantum m ...
argued that "mind, as manifested by the capacity to make choices, is to some extent inherent in every electron".
Other contemporary physicists and philosophers considered these arguments unconvincing.
Victor Stenger characterized quantum consciousness as a "myth" having "no scientific basis" that "should take its place along with gods, unicorns and dragons".
David Chalmers
David John Chalmers (; born 20 April 1966) is an Australian philosopher and cognitive scientist specializing in the areas of philosophy of mind and philosophy of language. He is a professor of philosophy and neural science at New York Univers ...
argues against quantum consciousness. He instead discusses how
quantum mechanics
Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, ...
may relate to
dualistic consciousness.
Chalmers is skeptical that any new physics can resolve the
hard problem of consciousness
The hard problem of consciousness is the problem of explaining why and how humans have qualia or phenomenal experiences. This is in contrast to the "easy problems" of explaining the physical systems that give us and other animals the ability to ...
.
Approaches
Bohm
David Bohm
David Joseph Bohm (; 20 December 1917 – 27 October 1992) was an American-Brazilian-British scientist who has been described as one of the most significant theoretical physicists of the 20th centuryPeat 1997, pp. 316-317 and who contributed ...
viewed
quantum theory and
relativity as contradictory, which implied a more fundamental level in the universe.
He claimed that both quantum theory and relativity pointed to this deeper theory, which he formulated as a quantum field theory. This more fundamental level was proposed to represent an undivided wholeness and an
implicate order
Implicate order and explicate order are ontological concepts for quantum theory coined by theoretical physicist David Bohm during the early 1980s. They are used to describe two different frameworks for understanding the same phenomenon or aspect of ...
, from which arises the
explicate order of the universe as we experience it.
Bohm's proposed order applies both to matter and consciousness. He suggested that it could explain the relationship between them. He saw mind and matter as projections into our explicate order from the underlying implicate order. Bohm claimed that when we look at matter, we see nothing that helps us to understand consciousness.
Bohm discussed the experience of listening to music. He believed that the feeling of movement and change that make up our experience of music derive from holding the immediate past and the present in the brain together. The musical notes from the past are transformations rather than memories. The notes that were implicated in the immediate past become explicate in the present. Bohm viewed this as consciousness emerging from the implicate order.
Bohm saw the movement, change or flow, and the coherence of experiences, such as listening to music, as a manifestation of the implicate order. He claimed to derive evidence for this from
Jean Piaget
Jean William Fritz Piaget (, , ; 9 August 1896 – 16 September 1980) was a Swiss psychologist known for his work on child development. Piaget's theory of cognitive development and epistemological view are together called "genetic epistemolo ...
's work on infants.
He held these studies to show that young children learn about time and space because they have a "hard-wired" understanding of movement as part of the implicate order. He compared this hard-wiring to
Chomsky's theory that grammar is hard-wired into human brains.
Bohm never proposed a specific means by which his proposal could be falsified, nor a neural mechanism through which his "implicate order" could emerge in a way relevant to consciousness.
He later collaborated on
Karl Pribram's
holonomic brain theory as a model of quantum consciousness.
According to philosopher
Paavo Pylkkänen, Bohm's suggestion "leads naturally to the assumption that the physical correlate of the
logical thinking process is at the classically describable level of the brain, while the basic thinking process is at the quantum-theoretically describable level".
It was suggested by theoretical physicists
David Bohm
David Joseph Bohm (; 20 December 1917 – 27 October 1992) was an American-Brazilian-British scientist who has been described as one of the most significant theoretical physicists of the 20th centuryPeat 1997, pp. 316-317 and who contributed ...
and
Basil Hiley
Basil J. Hiley (born 1935), is a British quantum physicist and professor emeritus of the University of London.
Long-time colleague of David Bohm, Hiley is known for his work with Bohm on implicate orders and for his work on algebraic description ...
that
mind and matter both
emerge from an "implicate order".
Bohm and Hiley's approach to mind and matter is supported by philosopher
Paavo Pylkkänen. Pylkkänen underlines "unpredictable, uncontrollable, indivisible and non-logical" features of conscious thought and draws parallels to a philosophical movement some call "post-phenomenology", in particular to
Pauli Pylkkö's notion of the "aconceptual experience", an unstructured, unarticulated and pre-logical experience.
Penrose and Hameroff
Theoretical physicist
Roger Penrose
Sir Roger Penrose (born 8 August 1931) is an English mathematician, mathematical physicist, philosopher of science and Nobel Laureate in Physics. He is Emeritus Rouse Ball Professor of Mathematics in the University of Oxford, an emeritus f ...
and
anaesthesiologist
Anesthesiology, anaesthesiology, or anaesthesia is the medical specialty concerned with the total perioperative care of patients before, during and after surgery. It encompasses anesthesia, intensive care medicine, critical emergency medicine, ...
Stuart Hameroff collaborated to produce the theory known as "
orchestrated objective reduction
Orchestrated objective reduction (Orch OR) is a theory which postulates that consciousness originates at the quantum level inside neurons, rather than the conventional view that it is a product of connections between neurons. The mechanism is he ...
" (Orch-OR). Penrose and Hameroff initially developed their ideas separately and later collaborated to produce Orch-OR in the early 1990s. They reviewed and updated their theory in 2013.
Penrose's argument stemmed from
Gödel's incompleteness theorems
Gödel's incompleteness theorems are two theorems of mathematical logic that are concerned with the limits of in formal axiomatic theories. These results, published by Kurt Gödel in 1931, are important both in mathematical logic and in the phil ...
. In his first book on consciousness, ''
The Emperor's New Mind
''The Emperor's New Mind: Concerning Computers, Minds and The Laws of Physics'' is a 1989 book by the mathematical physicist Sir Roger Penrose.
Penrose argues that human consciousness is non-algorithmic, and thus is not capable of being modele ...
'' (1989),
he argued that while a formal system cannot prove its own consistency, Gödel's unprovable results are provable by human mathematicians.
Penrose took this to mean that human mathematicians are not formal proof systems and not running a computable algorithm. According to Bringsjord and Xiao, this line of reasoning is based on fallacious
equivocation
In logic, equivocation ("calling two different things by the same name") is an informal fallacy resulting from the use of a particular word/expression in multiple senses within an argument.
It is a type of ambiguity that stems from a phrase havin ...
on the meaning of computation. In the same book, Penrose wrote: "One might speculate, however, that somewhere deep in the brain, cells are to be found of single quantum sensitivity. If this proves to be the case, then quantum mechanics will be significantly involved in brain activity."
Penrose determined that
wave function collapse
In quantum mechanics, wave function collapse occurs when a wave function—initially in a quantum superposition, superposition of several eigenstates—reduces to a single eigenstate due to interaction with the external world. This interaction is ...
was the only possible physical basis for a non-computable process. Dissatisfied with its randomness, he proposed a new form of wave function collapse that occurs in isolation and called it ''objective reduction''. He suggested each quantum superposition has its own piece of spacetime curvature and that when these become separated by more than one
Planck length, they become unstable and collapse.
Penrose suggested that ''objective reduction'' represents neither randomness nor algorithmic processing but instead a non-computable influence in
spacetime
In physics, spacetime is a mathematical model that combines the three dimensions of space and one dimension of time into a single four-dimensional manifold. Spacetime diagrams can be used to visualize relativistic effects, such as why differ ...
geometry from which mathematical understanding and, by later extension, consciousness derives.
Hameroff provided a hypothesis that
microtubule
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 1 ...
s would be suitable hosts for quantum behavior. Microtubules are composed of
tubulin
Tubulin in molecular biology can refer either to the tubulin protein superfamily of globular proteins, or one of the member proteins of that superfamily. α- and β-tubulins polymerize into microtubules, a major component of the eukaryotic cytoske ...
protein dimer
In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' has ...
subunits. The dimers each have
hydrophobic
In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water (known as a hydrophobe). In contrast, hydrophiles are attracted to water.
Hydrophobic molecules tend to be nonpolar and, ...
pockets that are 8 nm apart and may contain delocalized
π electrons. Tubulins have other smaller non-polar regions that contain π-electron-rich
indole
Indole is an aromatic heterocyclic organic compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other c ...
rings separated by about 2 nm. Hameroff proposed that these electrons are close enough to become entangled.
He originally suggested that the tubulin-subunit electrons would form a
Bose–Einstein condensate
In condensed matter physics, a Bose–Einstein condensate (BEC) is a state of matter that is typically formed when a gas of bosons at very low densities is cooled to temperatures very close to absolute zero (−273.15 °C or −459.6 ...
, but this was discredited.
He then proposed a Frohlich condensate, a hypothetical coherent oscillation of dipolar molecules, but this too was experimentally discredited.
In other words, there is a missing link between physics and neuroscience. For instance, the proposed predominance of A-lattice microtubules, more suitable for information processing, was falsified by Kikkawa ''et al.'',
who showed that all in vivo microtubules have a B lattice and a seam. The proposed existence of gap junctions between neurons and
glial cells
Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cells in the central nervous system (brain and spinal cord) and the peripheral nervous system that do not produce electrical impulses. They maintain homeostasis, form myel ...
was also falsified.
Orch-OR predicted that microtubule coherence reaches the synapses through dendritic lamellar bodies (DLBs), but De Zeeuw ''et al.'' proved this impossible
by showing that DLBs are micrometers away from gap junctions.
In 2014, Hameroff and Penrose claimed that the discovery of quantum vibrations in microtubules by Anirban Bandyopadhyay of the
National Institute for Materials Science
is an Independent Administrative Institution and one of the largest scientific research centers in Japan.
History
The growth and development of today's scientific research center has passed through several phases in a number of locations:
In ...
in Japan in March 2013 corroborates Orch-OR theory.
Experiments that showed that anaesthetic drugs reduce how long microtubules can sustain suspected quantum excitations appear to support the quantum theory of consciousness.
In 2022, results of two experiments at the
University of Alberta
The University of Alberta, also known as U of A or UAlberta, is a Public university, public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford,"A Gentleman of Strathcona – Alexande ...
and
Princeton University
Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the ...
were announced at
The Science of Consciousness conference, providing further evidence to support quantum processes operating within microtubules.
Although these theories are stated in a scientific framework, it is difficult to separate them from scientists' personal opinions. The opinions are often based on intuition or subjective ideas about the nature of consciousness. For example, Penrose wrote:
own point of view asserts that you can't even simulate conscious activity. What's going on in conscious thinking is something you couldn't properly imitate at all by computer.... If something behaves as though it's conscious, do you say it is conscious? People argue endlessly about that. Some people would say, "Well, you've got to take the operational viewpoint; we don't know what consciousness is. How do you judge whether a person is conscious or not? Only by the way they act. You apply the same criterion to a computer or a computer-controlled robot." Other people would say, "No, you can't say it feels something merely because it behaves as though it feels something." My view is different from both those views. The robot wouldn't even behave convincingly as though it was conscious unless it really was—which I say it couldn't be, if it's entirely computationally controlled.
Penrose continues:
A lot of what the brain does you could do on a computer. I'm not saying that all the brain's action is completely different from what you do on a computer. I am claiming that the actions of consciousness are something different. I'm not saying that consciousness is beyond physics, either—although I'm saying that it's beyond the physics we know now.... My claim is that there has to be something in physics that we don't yet understand, which is very important, and which is of a noncomputational character. It's not specific to our brains; it's out there, in the physical world. But it usually plays a totally insignificant role. It would have to be in the bridge between quantum and classical levels of behavior—that is, where quantum measurement comes in.
In 2010,
Lawrence Krauss
Lawrence Maxwell Krauss (born May 27, 1954) is an American theoretical physicist and cosmologist who previously taught at Arizona State University, Yale University, and Case Western Reserve University. He founded ASU's Origins Project, now c ...
was guarded in criticising Penrose's ideas. He said: "Roger Penrose has given lots of new-age crackpots ammunition... Many people are dubious that Penrose's suggestions are reasonable, because the brain is not an isolated quantum-mechanical system. To some extent it could be, because memories are stored at the molecular level, and at a molecular level quantum mechanics is significant."
Umezawa, Vitiello, Freeman
Hiroomi Umezawa
(September 20, 1924 – March 24, 1995) was a physicist and Distinguished Professor in the Department of Physics at the University of Wisconsin–Milwaukee and collaborators proposed a quantum field theory of memory storage. Giuseppe Vitiello and
Walter Freeman proposed a dialog model of the mind. This dialog takes place between the classical and the quantum parts of the brain. Their quantum field theory models of brain dynamics are fundamentally different from the Penrose–Hameroff theory.
Quantum brain dynamics
In
neuroscience
Neuroscience is the science, scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a Multidisciplinary approach, multidisciplinary science that combines physiology, an ...
, quantum brain dynamics (QBD) is a hypothesis to explain the function of the
brain
A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...
within the framework of
quantum field theory
In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines classical field theory, special relativity, and quantum mechanics. QFT is used in particle physics to construct physical models of subatomic particles and ...
.
As described by Harald Atmanspacher, "Since quantum theory is the most fundamental theory of matter that is currently available, it is a legitimate question to ask whether quantum theory can help us to understand consciousness."
The original motivation in the early 20th century for relating quantum theory to consciousness was essentially philosophical. It is fairly plausible that conscious free decisions (“free will”) are problematic in a perfectly deterministic world, so quantum randomness might indeed open up novel possibilities for free will. (On the other hand, randomness is problematic for goal-directed volition!)
Ricciardi and Umezawa proposed in 1967 a general theory of quanta of long-range
coherent
Coherence, coherency, or coherent may refer to the following:
Physics
* Coherence (physics), an ideal property of waves that enables stationary (i.e. temporally and spatially constant) interference
* Coherence (units of measurement), a deriv ...
waves within and between brain cells, and showed a possible mechanism of memory storage and retrieval in terms of
Nambu–Goldstone boson
In particle and condensed matter physics, Goldstone bosons or Nambu–Goldstone bosons (NGBs) are bosons that appear necessarily in models exhibiting spontaneous breakdown of continuous symmetries. They were discovered by Yoichiro Nambu in part ...
s.
This was later fleshed out into a theory encompassing all biological cells and systems in the quantum biodynamics of Del Giudice and co-authors.
Mari Jibu and Kunio Yasue later popularized these results and discussed the implications towards consciousness.
Umezawa emphasizes that macroscopic and microscopic ordered states are both of quantum origin according to quantum field theory and points out the shortcomings of classical neuronal models in describing them. In 1981, theoretical exploration of the
Ising model
The Ising model () (or Lenz-Ising model or Ising-Lenz model), named after the physicists Ernst Ising and Wilhelm Lenz, is a mathematical model of ferromagnetism in statistical mechanics. The model consists of discrete variables that represent ...
in yielded an exact solution on closed trees with arbitrary branching ratios greater than two, exhibiting an unusual
phase transition
In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states ...
in local-apex and long-range site-site correlations. This finding directly raises the possibility of multiple cooperative modes being present in ordering states long-range within neural networks and their constituents, with cooperative effects of the closed tree Ising model (structurally and connectivity dependent, with critical point a function of branching ratio and site-to-site energies of interaction) and Umezawa ordering of states (less structure dependent and with significantly greater degrees of freedom) independently or collectively guiding overall long-range macroscopic ordering often associated with higher cognitive functions in QBD.
Pribram
Karl Pribram's
holonomic brain theory (quantum holography) invoked quantum mechanics to explain higher-order processing by the mind. He argued that his holonomic model solved the
binding problem The consciousness and binding problem is the problem of how objects, background and abstract or emotional features are combined into a single experience.
The binding problem refers to the overall encoding of our brain circuits for the combination o ...
. Pribram collaborated with Bohm in his work on quantum approaches to mind and he provided evidence on how much of the processing in the brain was done in wholes. He proposed that ordered water at
dendritic
Dendrite derives from the Greek word "dendron" meaning ( "tree-like"), and may refer to:
Biology
*Dendrite, a branched projection of a neuron
* Dendrite (non-neuronal), branching projections of certain skin cells and immune cells
Physical
*Dendr ...
membrane surfaces might operate by structuring
Bose–Einstein condensation Bose–Einstein may refer to:
* Bose–Einstein condensate
** Bose–Einstein condensation (network theory)
* Bose–Einstein correlations
* Bose–Einstein statistics
In quantum statistics, Bose–Einstein statistics (B–E statistics) describe ...
supporting quantum dynamics.
Stapp
Henry Stapp
Henry Pierce Stapp (born March 23, 1928 in Cleveland, Ohio) is an American mathematical physicist, known for his work in quantum mechanics, particularly the development of axiomatic S-matrix theory, the proofs of strong nonlocality properties, an ...
proposed that quantum waves are reduced only when they interact with consciousness. He argues from the that the quantum state collapses when the observer selects one among the alternative quantum possibilities as a basis for future action. The collapse, therefore, takes place in the expectation that the observer associated with the state. Stapp's work drew criticism from scientists such as David Bourget and Danko Georgiev.
[
] Georgiev
[
][
] criticized Stapp's model in two respects:
* Stapp's mind does not have its own
wavefunction
A wave function in quantum physics is a mathematical description of the quantum state of an isolated quantum system. The wave function is a complex-valued probability amplitude, and the probabilities for the possible results of measurements ...
or
density matrix
In quantum mechanics, a density matrix (or density operator) is a matrix that describes the quantum state of a physical system. It allows for the calculation of the probabilities of the outcomes of any measurement performed upon this system, using ...
, but nevertheless can act upon the brain using
projection operators. Such usage is not compatible with standard quantum mechanics because one can attach any number of ghostly minds to any point in space that act upon physical quantum systems with any projection operators. Stapp's model therefore negates "the prevailing principles of physics".
* Stapp's claim that
quantum Zeno effect
The quantum Zeno effect (also known as the Turing paradox) is a feature of quantum-mechanical systems allowing a particle's time evolution to be slowed down by measuring it frequently enough with respect to some chosen measurement setting.
Somet ...
is robust against environmental decoherence directly contradicts a basic theorem in
quantum information theory
Quantum information is the information of the quantum state, state of a quantum system. It is the basic entity of study in quantum information theory, and can be manipulated using quantum information processing techniques. Quantum information re ...
: that acting with projection operators upon the density matrix of a quantum system can only increase the system's
von Neumann entropy
In physics, the von Neumann entropy, named after John von Neumann, is an extension of the concept of Gibbs entropy from classical statistical mechanics to quantum statistical mechanics. For a quantum-mechanical system described by a density matrix ...
.
Stapp has responded to both of Georgiev's objections.
David Pearce
British philosopher
David Pearce defends what he calls physicalistic idealism ("the non-materialist physicalist claim that reality is fundamentally experiential and that the natural world is exhaustively described by the equations of physics and their solutions") and has conjectured that unitary conscious minds are physical states of
quantum coherence
In physics, two wave sources are coherent if their frequency and waveform are identical. Coherence is an ideal property of waves that enables stationary (i.e., temporally or spatially constant) interference. It contains several distinct concepts, ...
(neuronal superpositions).
This conjecture is, according to Pearce, amenable to falsification, unlike most theories of consciousness, and Pearce has outlined an experimental protocol describing how the hypothesis could be tested using
matter-wave interferometry to detect
nonclassical interference patterns of
neuronal superpositions at the onset of
thermal decoherence.
Pearce admits that his ideas are "highly speculative", "counterintuitive", and "incredible".
Catecholaminergic Neuron Electron Transport (CNET)
CNET is a hypothesized neural signaling mechanism in catecholaminergic neurons that would use quantum mechanical electron transport. The hypothesis is based in part on the observation by many independent researchers that electron tunneling occurs in ferritin, an iron storage protein that is prevalent in those neurons, at room temperature and ambient conditions. The hypothesized function of this mechanism is to assist in action selection, but the mechanism itself would be capable of integrating millions of cognitive and sensory neural signals using a physical mechanism associated with strong electron-electron interactions. Each tunneling event would involve a collapse of an electron wave function, but the collapse would be incidental to the physical effect created by strong electron-electron interactions.
CNET predicted a number of physical properties of these neurons that have been subsequently observed experimentally, such as electron tunneling in substantia nigra pars compacta (SNc) tissue and the presence of disordered arrays of ferritin in SNc tissue. The hypothesis also predicted that disordered ferritin arrays like those found in SNc tissue should be capable of supporting long-range electron transport and providing a switching or routing function, both of which have also been subsequently observed.
Another prediction of CNET was that the largest SNc neurons should mediate action selection. This prediction was contrary to earlier proposals about the function of those neurons at that time, which were based on predictive reward dopamine signaling. A team led by Dr. Pascal Kaiser of Harvard Medical School subsequently demonstrated that those neurons do in fact code movement, consistent with the earlier predictions of CNET. While the CNET mechanism has not yet been directly observed, it may be possible to do so using quantum dot fluorophores tagged to ferritin or other methods for detecting electron tunneling.
CNET is applicable to a number of different consciousness models as a binding or action selection mechanism, such as
Integrated Information Theory
Integrated information theory (IIT) attempts to provide a framework capable of explaining why some physical systems (such as human brains) are conscious, why they feel the particular way they do in particular states (e.g. why our visual field appe ...
(IIT) an
Sensorimotor Theory(SMT). It is noted that many existing models of consciousness fail to specifically address action selection or binding. For example, O’Regan and Noë call binding a “pseudo problem,” but also state that “the fact that object attributes seem perceptually to be part of a single object does not require them to be ‘represented’ in any unified kind of way, for example, at a single location in the brain, or by a single process. They may be so represented, but there is no logical necessity for this.” Simply because there is no “logical necessity” for a physical phenomenon does not mean that it does not exist, or that once it is identified that it can be ignored. Likewise,
global workspace theory (GWT) models appear to treat dopamine as modulatory, based on the prior understanding of those neurons from predictive reward dopamine signaling research, but GWT models could be adapted to include modeling of moment-by-moment activity in the striatum to mediate action selection, as observed by Kaiser. CNET is applicable to those neurons as a selection mechanism for that function, as otherwise that function could result in seizures from simultaneous actuation of competing sets of neurons. While CNET by itself is not a model of consciousness, it is able to integrate different models of consciousness through neural binding and action selection. However, a more complete understanding of how CNET might relate to consciousness would require a better understanding of strong electron-electron interactions in ferritin arrays, which implicates the
many-body problem
The many-body problem is a general name for a vast category of physical problems pertaining to the properties of microscopic systems made of many interacting particles. ''Microscopic'' here implies that quantum mechanics has to be used to provid ...
.
Experiments
In 2022, neuroscientists reported experimental
MRI
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...
results that so far appear to imply nuclear proton
spins
The spins (as in having "the spins")Diane Marie Leiva. ''The Florida State University College of Education''Women's Voices on College Drinking: The First-Year College Experience"/ref> is an adverse reaction of intoxication that causes a state of ...
of 'brain water' in the
brain
A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...
s of human participants were
entangled, suggesting
brain functions
A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...
that operate non-classically which may support quantum mechanisms being involved in consciousness as the signal pattern declined when human participants fell asleep. However, the results are far from unambiguous and if such brain functions indeed exist and are involved in conscious cognition, the extent and nature of their involvement in consciousness remains unknown.
Criticism
These hypotheses of the quantum mind remain hypothetical speculation, as Penrose and Pearce admit in their discussions. Until they make a prediction that is tested by experimentation, the hypotheses aren't based on empirical evidence. According to Krauss, "It is true that quantum mechanics is extremely strange, and on extremely small scales for short times, all sorts of weird things happen. And in fact, we can make weird quantum phenomena happen. But what quantum mechanics doesn't change about the universe is, if you want to change things, you still have to do something. You can't change the world by thinking about it."
The process of testing the hypotheses with experiments is fraught with conceptual/theoretical, practical, and ethical problems.
Conceptual problems
The idea that a quantum effect is necessary for consciousness to function is still in the realm of philosophy. Penrose proposes that it is necessary, but other theories of consciousness do not indicate that it is needed. For example,
Daniel Dennett proposed a theory called
multiple drafts model
Daniel Dennett's multiple drafts model of consciousness is a physicalist theory of consciousness based upon cognitivism, which views the mind in terms of information processing. The theory is described in depth in his book, ''Consciousness Explai ...
, which doesn't indicate that quantum effects are needed, in his 1991 book ''
Consciousness Explained
''Consciousness Explained'' is a 1991 book by the American philosopher Daniel Dennett, in which the author offers an account of how consciousness arises from interaction of physical and cognitive processes in the brain. Dennett describes consciou ...
''.
A philosophical argument on either side isn't scientific proof, although philosophical analysis can indicate key differences in the types of models and show what type of experimental differences might be observed. But since there isn't a clear consensus among philosophers, there isn't conceptual support that a quantum mind theory is needed.
There are computers that are specifically designed to compute using quantum-mechanical effects.
Quantum computing
Quantum computing is a type of computation whose operations can harness the phenomena of quantum mechanics, such as superposition, interference, and entanglement. Devices that perform quantum computations are known as quantum computers. Though ...
is
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...
using
quantum-mechanical phenomena
A phenomenon ( : phenomena) is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which ''cannot'' be directly observed. Kant was heavily influenced by Gottfried W ...
, such as
superposition and
entanglement. They are different from
binary
Binary may refer to:
Science and technology Mathematics
* Binary number, a representation of numbers using only two digits (0 and 1)
* Binary function, a function that takes two arguments
* Binary operation, a mathematical operation that ta ...
digital electronic computer
In computer science, a digital electronic computer is a computer machine which is both an electronic computer and a digital computer. Examples of digital electronic computers include the IBM PC, the Apple Macintosh, and modern smartphones. When ...
s based on
transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch e ...
s. Whereas common digital computing requires that the data be encoded into binary digits (
bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...
s), each of which is always in one of two definite states (0 or 1), quantum computation uses
quantum bits
In physics, a quantum (plural quanta) is the minimum amount of any physical entity ( physical property) involved in an interaction. The fundamental notion that a physical property can be "quantized" is referred to as "the hypothesis of quantizat ...
, which can be in
superpositions of states. One of the greatest challenges is controlling or removing
quantum decoherence. This usually means isolating the system from its environment, as interactions with the external world cause the system to decohere. Some quantum computers require their qubits to be cooled to 20 millikelvins in order to prevent significant decoherence. As a result, time-consuming tasks may render some quantum algorithms inoperable, as maintaining the state of qubits long enough eventually corrupts the superpositions. There aren't any obvious analogies between the functioning of quantum computers and the human brain. Some hypothetical models of quantum mind have proposed mechanisms for maintaining quantum coherence in the brain, but they have not been shown to operate.
Quantum entanglement
Quantum entanglement is the phenomenon that occurs when a group of particles are generated, interact, or share spatial proximity in a way such that the quantum state of each particle of the group cannot be described independently of the state of ...
is a physical phenomenon often invoked for quantum mind models. This effect occurs when pairs or groups of
particle
In the Outline of physical science, physical sciences, a particle (or corpuscule in older texts) is a small wikt:local, localized physical body, object which can be described by several physical property, physical or chemical property, chemical ...
s interact so that the
quantum state
In quantum physics, a quantum state is a mathematical entity that provides a probability distribution for the outcomes of each possible measurement on a system. Knowledge of the quantum state together with the rules for the system's evolution in ...
of each particle cannot be described independently of the other(s),
even when the particles are separated by a large distance. Instead, a quantum state has to be described for the whole system.
Measurements
Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events.
In other words, measurement is a process of determining how large or small a physical quantity is as compared t ...
of physical properties such as
position
Position often refers to:
* Position (geometry), the spatial location (rather than orientation) of an entity
* Position, a job or occupation
Position may also refer to:
Games and recreation
* Position (poker), location relative to the dealer
* ...
,
momentum
In Newtonian mechanics, momentum (more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. If is an object's mass an ...
,
spin, and
polarization, performed on entangled particles are found to be
correlated
In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistic ...
. If one particle is measured, the same property of the other particle immediately adjusts to maintain the conservation of the physical phenomenon. According to the formalism of quantum theory, the effect of measurement happens instantly, no matter how far apart the particles are.
[.] It is not possible to use this effect to transmit classical information at faster-than-light speeds (see
Faster-than-light § Quantum mechanics). Entanglement is broken when the entangled particles
decohere
Quantum decoherence is the loss of quantum coherence. In quantum mechanics, particles such as electrons are described by a wave function, a mathematical representation of the quantum state of a system; a probabilistic interpretation of the wave ...
through interaction with the environment—for example, when a measurement is made
[Asher Peres, '' Quantum Theory: Concepts and Methods'', Kluwer, 1993; p. 115.] or the particles undergo random collisions or interactions. According to Pearce, "In neuronal networks, ion–ion scattering, ion–water collisions, and long-range Coulomb interactions from nearby ions all contribute to rapid decoherence times; but thermally induced decoherence is even harder experimentally to control than collisional decoherence." He anticipated that quantum effects would have to be measured in femtoseconds, a trillion times faster than the rate at which neurons function (milliseconds).
Another possible conceptual approach is to use quantum mechanics as an analogy to understand a different field of study like consciousness, without expecting that the laws of quantum physics will apply. An example of this approach is the idea of
Schrödinger's cat
In quantum mechanics, Schrödinger's cat is a thought experiment that illustrates a paradox of quantum superposition. In the thought experiment, a hypothetical cat may be considered simultaneously both alive and dead, while it is unobserved in ...
.
Erwin Schrödinger
Erwin Rudolf Josef Alexander Schrödinger (, ; ; 12 August 1887 – 4 January 1961), sometimes written as or , was a Nobel Prize-winning Austrian physicist with Irish citizenship who developed a number of fundamental results in quantum theo ...
described how one could, in principle, create entanglement of a large-scale system by making it dependent on an elementary particle in a superposition. He proposed a scenario with a cat in a locked steel chamber, wherein the cat's survival depended on the state of a
radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...
atom—whether it had decayed and emitted radiation. According to Schrödinger, the Copenhagen interpretation implies that ''the cat is both alive and dead'' until the state has been observed. Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; he intended the example to illustrate the absurdity of the existing view of quantum mechanics.
[
] But since Schrödinger's time, physicists have given other
interpretations of the mathematics of quantum mechanics, some of which regard the "alive and dead" cat superposition as quite real.
Schrödinger's famous
thought experiment
A thought experiment is a hypothetical situation in which a hypothesis, theory, or principle is laid out for the purpose of thinking through its consequences.
History
The ancient Greek ''deiknymi'' (), or thought experiment, "was the most anc ...
poses the question, "''when'' does a quantum system stop existing as a superposition of states and become one or the other?" In the same way, one can ask whether the act of making a decision is analogous to having a superposition of states of two decision outcomes, so that making a decision means "opening the box" to reduce the brain from a combination of states to one state. This analogy about decision-making uses a formalism derived from quantum mechanics, but doesn't indicate the actual mechanism by which the decision is made. In this way, the idea is similar to
quantum cognition
Quantum cognition is an emerging field which applies the mathematical formalism of quantum theory to model cognitive phenomena such as information processing by the human brain, language, decision making, human memory, concepts and conceptual re ...
. This field clearly distinguishes itself from the quantum mind, as it is not reliant on the hypothesis that there is something micro-physical quantum-mechanical about the brain. Quantum cognition is based on the quantum-like paradigm, generalized quantum paradigm, or quantum structure paradigm that information processing by complex systems such as the brain can be mathematically described in the framework of quantum information and quantum probability theory. This model uses quantum mechanics only as an analogy, but doesn't propose that quantum mechanics is the physical mechanism by which it operates. For example, quantum cognition proposes that some decisions can be analyzed as if there is interference between two alternatives, but it is not a physical quantum interference effect.
Practical problems
The quantum mind hypothesis remains theoretical until and unless quantum effect on neurological or mental processes can be validated through scientific experiment. Is there a way to show that consciousness is impossible without a quantum effect? Can a sufficiently complex digital, non-quantum computer be shown to be incapable of consciousness? Perhaps a quantum computer will show that quantum effects are needed. In any case, complex computers that are either digital or quantum computers may be built. These could demonstrate which type of computer is capable of conscious, intentional thought. But they don't exist yet, and no experimental test has been demonstrated.
Quantum mechanics is a mathematical model that can provide some extremely accurate numerical predictions.
Richard Feynman
Richard Phillips Feynman (; May 11, 1918 – February 15, 1988) was an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superflu ...
called quantum electrodynamics, based on the quantum-mechanics formalism, "the jewel of physics" for its
extremely accurate predictions of quantities like the
anomalous magnetic moment
In quantum electrodynamics, the anomalous magnetic moment of a particle is a contribution of effects of quantum mechanics, expressed by Feynman diagrams with loops, to the magnetic moment of that particle. (The ''magnetic moment'', also called '' ...
of the electron and the
Lamb shift
In physics, the Lamb shift, named after Willis Lamb, is a difference in energy between two energy levels 2''S''1/2 and 2''P''1/2 (in term symbol notation) of the hydrogen atom which was not predicted by the Dirac equation, according to which th ...
of the
energy level
A quantum mechanical system or particle that is bound—that is, confined spatially—can only take on certain discrete values of energy, called energy levels. This contrasts with classical particles, which can have any amount of energy. The te ...
s of
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
.
So it is not impossible that the model could provide an accurate prediction about consciousness that would confirm that a quantum effect is involved. If the mind depends on quantum mechanical effects, the true proof is to find an experiment that provides a calculation that can be compared to experimental measurement. It has to show a measurable difference between a classical computation result in a brain and one that involves quantum effects.
The main theoretical argument against the quantum-mind hypothesis is the assertion that quantum states in the brain would lose coherency before they reached a scale where they could be useful for neural processing. This supposition was elaborated by
Max Tegmark
Max Erik Tegmark (born 5 May 1967) is a Swedish-American physicist, cosmologist and machine learning researcher. He is a professor at the Massachusetts Institute of Technology and the president of the Future of Life Institute. He is also a scienti ...
. His calculations indicate that quantum systems in the brain decohere at sub-picosecond timescales.
No response by a brain has shown computational results or reactions on this fast of a timescale. Typical reactions are on the order of milliseconds, trillions of times longer than sub-picosecond timescales.
Daniel Dennett uses an experimental result in support of his
multiple drafts model
Daniel Dennett's multiple drafts model of consciousness is a physicalist theory of consciousness based upon cognitivism, which views the mind in terms of information processing. The theory is described in depth in his book, ''Consciousness Explai ...
of
an optical illusion that happens on a time scale of less than a second or so. In this experiment, two different-colored lights, with an angular separation of a few degrees at the eye, are flashed in succession. If the interval between the flashes is less than a second or so, the first light that is flashed appears to move across to the position of the second light. Furthermore, the light seems to change color as it moves across the visual field. A green light will appear to turn red as it seems to move across to the position of a red light. Dennett asks how we could see the light change color before the second light is observed.
Velmans argues that the
cutaneous rabbit illusion
The cutaneous rabbit illusion (also known as cutaneous saltation and sometimes the cutaneous rabbit effect or CRE) is a tactile illusion evoked by tapping two or more separate regions of the skin in rapid succession. The illusion is most readily e ...
, another illusion that happens in about a second, demonstrates that there is a delay while modelling occurs in the brain and that this delay was discovered by
Libet.
[ (Commentary on Dennett & Kinsbourne "Time and the observer", BBS, 1992, 15(2): 183–201.)] These slow illusions that happen at times of less than a second don't support a proposal that the brain functions on the picosecond time scale.
According to David Pearce, a demonstration of picosecond effects is "the fiendishly hard part – feasible in principle, but an experimental challenge still beyond the reach of contemporary molecular matter-wave interferometry.
..The conjecture predicts that we'll discover the interference signature of sub-femtosecond macro-superpositions."
Penrose says:
The problem with trying to use quantum mechanics in the action of the brain is that if it were a matter of quantum nerve signals, these nerve signals would disturb the rest of the material in the brain, to the extent that the quantum coherence would get lost very quickly. You couldn't even attempt to build a quantum computer out of ordinary nerve signals, because they're just too big and in an environment that's too disorganized. Ordinary nerve signals have to be treated classically. But if you go down to the level of the microtubules, then there's an extremely good chance that you can get quantum-level activity inside them.
For my picture, I need this quantum-level activity in the microtubules; the activity has to be a large-scale thing that goes not just from one microtubule to the next but from one nerve cell to the next, across large areas of the brain. We need some kind of coherent activity of a quantum nature which is weakly coupled to the computational activity that Hameroff argues is taking place along the microtubules.
There are various avenues of attack. One is directly on the physics, on quantum theory, and there are certain experiments that people are beginning to perform, and various schemes for a modification of quantum mechanics. I don't think the experiments are sensitive enough yet to test many of these specific ideas. One could imagine experiments that might test these things, but they'd be very hard to perform.
A demonstration of a quantum effect in the brain has to explain this problem or explain why it is not relevant, or that the brain somehow circumvents the problem of the loss of quantum coherency at body temperature. As Penrose proposes, it may require a new type of physical theory.
Ethical problems
Quantum mind theories are often conflated with
quantum woo, which is the justification of irrational beliefs by an obfuscatory reference to quantum physics.
Buzzwords like "energy field", "probability wave", or "wave-particle duality" are used to magically turn thoughts into something tangible in order to directly affect the universe.
Some have turned quantum woo into a career, such as
Deepak Chopra, who often presents ill-defined concepts of quantum physics as proof for God,
a "quantum soul" existing "apart from the body"
and human "access to a field of infinite possibilities".
According to Lawrence Krauss, "You should be wary whenever you hear something like 'Quantum mechanics connects you with the universe' ... or 'quantum mechanics unifies you with everything else'. You can begin to be skeptical that the speaker is somehow trying to use quantum mechanics to argue fundamentally that you can change the world by thinking about it."
A subjective feeling is not sufficient to make this determination. Humans don't have a reliable subjective feeling for how we do a lot of functions. According to Daniel Dennett, "On this topic, ''Everybody's an expert...'' but they think that they have a particular personal authority about the nature of their own conscious experiences that can trump any hypothesis they find unacceptable."
An ethically objectionable practice by proponents of quantum mind theories involves the practice of using quantum-mechanical terms in an effort to make the argument sound more impressive, even when they know that those terms are irrelevant. Dale DeBakcsy notes that "trendy parapsychologists, academic relativists, and even the
Dalai Lama
Dalai Lama (, ; ) is a title given by the Tibetan people to the foremost spiritual leader of the Gelug or "Yellow Hat" school of Tibetan Buddhism, the newest and most dominant of the four major schools of Tibetan Buddhism. The 14th and current Dal ...
have all taken their turn at robbing modern physics of a few well-sounding phrases and stretching them far beyond their original scope in order to add scientific weight to various pet theories". At the very least, these proponents must make a clear statement about whether quantum formalism is being used as an analogy or as an actual physical mechanism, and what evidence they are using for support. An ethical statement by a researcher should specify what kind of relationship their hypothesis has to the physical laws.
Misleading statements of this type have been given by, for example,
Deepak Chopra.
Chopra has commonly referred to topics such as
quantum healing
Quantum healing is a pseudoscientific mixture of ideas which purportedly draws from quantum mechanics, psychology, philosophy, and neurophysiology. Advocates of quantum healing assert that quantum phenomena govern health and wellbeing. There a ...
or quantum effects of consciousness. Seeing the human body as being undergirded by a "quantum-mechanical body" composed not of matter but of energy and information, he believes that "human aging is fluid and changeable; it can speed up, slow down, stop for a time, and even reverse itself", as determined by one's state of mind.
Robert Carroll states that Chopra attempts to integrate
Ayurveda
Ayurveda () is an alternative medicine system with historical roots in the Indian subcontinent. The theory and practice of Ayurveda is pseudoscientific. Ayurveda is heavily practiced in India and Nepal, where around 80% of the population repo ...
with quantum mechanics to justify his teachings.
[.] Chopra argues that what he calls "quantum healing" cures any manner of ailments, including cancer, through effects that he claims are literally based on the same principles as quantum mechanics.
[ This has led physicists to object to his use of the term ''quantum'' in reference to medical conditions and the human body.] Chopra said: "I think quantum theory has a lot of things to say about the observer effect Observer effect, observer bias, observation bias, etc. may refer to a number of concepts, some of them closely related:
General experimental biases
* Hawthorne effect, a form of reactivity in which subjects modify an aspect of their behavior, in ...
, about non-locality, about correlations. So I think there’s a school of physicists who believe that consciousness has to be equated, or at least brought into the equation, in understanding quantum mechanics." On the other hand, he also claims that " uantum effects arejust a metaphor. Just like an electron or a photon is an indivisible unit of information and energy, a thought is an indivisible unit of consciousness." In his book ''Quantum Healing'', Chopra stated the conclusion that quantum entanglement
Quantum entanglement is the phenomenon that occurs when a group of particles are generated, interact, or share spatial proximity in a way such that the quantum state of each particle of the group cannot be described independently of the state of ...
links everything in the Universe, and therefore it must create consciousness. In either case, the references to the word "quantum" don't mean what a physicist would claim, and arguments that use the word "quantum" shouldn't be taken as scientifically proven.
Chris Carter includes statements in his book ''Science and Psychic Phenomena'' of quotes from quantum physicists in support of psychic phenomena. In a review of the book, Benjamin Radford wrote that Carter used such references to "quantum physics, which he knows nothing about and which he (and people like Deepak Chopra) love to cite and reference because it sounds mysterious and paranormal.... Real, actual physicists I've spoken to break out laughing at this crap.... If Carter wishes to posit that quantum physics provides a plausible mechanism for psi, then it is his responsibility to show that, and he clearly fails to do so." Sharon Hill has studied amateur paranormal research groups, and these groups like to use "vague and confusing language: ghosts 'use energy', are made up of 'magnetic fields', or are associated with a 'quantum state.
Statements like these about quantum mechanics indicate a temptation to misinterpret technical, mathematical terms like entanglement in terms of mystical feelings. This approach can be interpreted as a kind of scientism
Scientism is the opinion that science and the scientific method are the best or only way to render truth about the world and reality.
While the term was defined originally to mean "methods and attitudes typical of or attributed to natural scientis ...
, using the language and authority of science when the scientific concepts don't apply.
Critics of the quantum mind hypothesis do not deny that quantum effects are involved in computations in the brain. But as these effects are relevant only at very small scales, e.g. by determining the properties and structure of proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
and neurotransmitters
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell.
Neur ...
, critics consider them irrelevant to consciousness emerging as a macroscopic phenomenon. As Daniel Dennett said, "quantum effects are there in your car, your watch, and your computer. But most things — most macroscopic objects — are, as it were, oblivious to quantum effects. They don't amplify them; they don't hinge on them."
Lawrence Krauss said: "We're also connected to the universe by gravity, and we're connected to the planets by gravity. But that doesn't mean that astrology is true.... Often, people who are trying to sell whatever it is they're trying to sell try to justify it on the basis of science. Everyone knows quantum mechanics is weird, so why not use that to justify it? ... I don't know how many times I've heard people say, 'Oh, I love quantum mechanics because I'm really into meditation, or I love the spiritual benefits that it brings me.' But quantum mechanics, for better or worse, doesn't bring any more spiritual benefits than gravity does."
See also
* Artificial consciousness
* Bohm interpretation of quantum mechanics
* Coincidence detection in neurobiology
Coincidence detection in the context of neurobiology is a process by which a neuron or a neural circuit can encode information by detecting the occurrence of temporally close but spatially distributed input signals. Coincidence detectors influen ...
* Critical brain hypothesis
* Electromagnetic theories of consciousness
The electromagnetic theories of consciousness propose that consciousness can be understood as an electromagnetic phenomenon.
Overview
Theorists differ in how they relate consciousness to electromagnetism. Electromagnetic ''field'' theories (or " ...
* Evolutionary neuroscience
Evolutionary neuroscience is the scientific study of the evolution of nervous systems. Evolutionary neuroscientists investigate the evolution and natural history of nervous system structure, functions and emergent properties. The field draws on c ...
* Many-minds interpretation The many-minds interpretation of quantum mechanics extends the many-worlds interpretation by proposing that the distinction between worlds should be made at the level of the mind of an individual observer. The concept was first introduced in 1970 b ...
* Neuroplasticity
Neuroplasticity, also known as neural plasticity, or brain plasticity, is the ability of Neural circuit, neural networks in the brain to change through growth and reorganization. It is when the brain is rewired to function in some way that diffe ...
* Hameroff-Penrose Orchestrated Objective Reduction
* Hard problem of consciousness
* Holonomic brain theory
Holonomic brain theory, also known as The Holographic Brain, is a branch of neuroscience investigating the idea that human consciousness is formed by quantum effects in or between brain cells. Holonomic refers to representations in a Hilbert phas ...
* Mechanism (philosophy)
Mechanism is the belief that natural wholes (principally living things) are similar to complicated machines or artifacts, composed of parts lacking any intrinsic relationship to each other.
The doctrine of mechanism in philosophy comes in two dif ...
* Quantum cognition
Quantum cognition is an emerging field which applies the mathematical formalism of quantum theory to model cognitive phenomena such as information processing by the human brain, language, decision making, human memory, concepts and conceptual re ...
* Quantum neural network
Quantum neural networks are computational neural network models which are based on the principles of quantum mechanics. The first ideas on quantum neural computation were published independently in 1995 by Subhash Kak and Ron Chrisley, engaging w ...
References
Further reading
*
*
*
*
*
* McFadden, Johnjoe (2000
''Quantum Evolution''
HarperCollins. ; . Final chapter on the quantum 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 that serves as a followup to his 1989 book '' The Emperor's New Mind: Concerning Computers, Minds and The Laws of ...
'', 1994 book by Roger Penrose
Sir Roger Penrose (born 8 August 1931) is an English mathematician, mathematical physicist, philosopher of science and Nobel Laureate in Physics. He is Emeritus Rouse Ball Professor of Mathematics in the University of Oxford, an emeritus f ...
* ''Quantum Aspects of Life'' (book)
External links
Center for Consciousness Studies
directed by Stuart Hameroff
PhilPapers on Philosophy of Mind
edited by David Bourget and David Chalmers
David John Chalmers (; born 20 April 1966) is an Australian philosopher and cognitive scientist specializing in the areas of philosophy of mind and philosophy of language. He is a professor of philosophy and neural science at New York Univers ...
Quantum Approaches to Consciousness
entry in Stanford Encyclopedia of Philosophy
The ''Stanford Encyclopedia of Philosophy'' (''SEP'') combines an online encyclopedia of philosophy with peer-reviewed publication of original papers in philosophy, freely accessible to Internet users. It is maintained by Stanford University. Eac ...
Quantum-Mind
founded by Simon Raggett
{{Consciousness
Theory of mind