Is mind quantum-like? Is consciousness quantum physical? Does consciousness have a role to play in the emergence of the classical world from the underlying quantum universe? Or is this dichotomy between classical and quantum an illusion? How can world philosophies enrich our views on these matters and interact with the best scientific theories? These are some questions that motivated us to conceive the current book. We also felt an urgent need to discuss the central philosophical questions haunting the emerging frameworks of quantum cognition and quantum-like framework (QLF). We have observed that there are very good technical or mathematical works being done in the emerging fields of quantum cognition and QLF, but there is still a great need for exploring the underlying and open philosophical questions they demand. Quantum cognition developed as a frontier research programme in understanding various cognitive phenomena that are hard or impossible to describe based on classical cognitive science paradigm. Classical cognitive science draws philosophically and mathematically from classical physics and classical probability theory. For example, cognitive realism thinking is deeply motivated by the scientific realism of classical physics. However, as we explore, there are numerous empirical findings which demonstrate clearly that human mind and cognitive processes exhibit features that are more quantum-like. Central to these features are indeterminacy, context dependence, and complementarity of cognitive phenomena, for example, perception, information retrieval, and even qualia. Many good works in the previous decade have demonstrated the efficacy of quantum-like mathematical modelling in such cases. However, given that efficacy, we cannot simply conclude that mind is quantum. Rather there are features that go beyond what is allowed in standard quantum formalism.
Is mind quantum-like? Is consciousness quantum physical? Does consciousness have a role to play in the emergence of the classical world from the underlying quantum universe? Or is this dichotomy between classical and quantum an illusion? How can world philosophies enrich our views on these matters and interact with the best scientific theories? These are some questions that motivated us to conceive the current book. We also felt an urgent need to discuss the central philosophical questions haunting the emerging frameworks of quantum cognition and quantum-like framework (QLF). We have observed that there are very good technical or mathematical works being done in the emerging fields of quantum cognition and QLF, but there is still a great need for exploring the underlying and open philosophical questions they demand. Quantum cognition developed as a frontier research programme in understanding various cognitive phenomena that are hard or impossible to describe based on classical cognitive science paradigm. Classical cognitive science draws philosophically and mathematically from classical physics and classical probability theory. For example, cognitive realism thinking is deeply motivated by the scientific realism of classical physics. However, as we explore, there are numerous empirical findings which demonstrate clearly that human mind and cognitive processes exhibit features that are more quantum-like. Central to these features are indeterminacy, context dependence, and complementarity of cognitive phenomena, for example, perception, information retrieval, and even qualia. Many good works in the previous decade have demonstrated the efficacy of quantum-like mathematical modelling in such cases. However, given that efficacy, we cannot simply conclude that mind is quantum. Rather there are features that go beyond what is allowed in standard quantum formalism.
This is a unique text that explores quantum-like modelling frameworks that connect quantum mechanics with cognitive science and consciousness studies to propose a new ontological framework that transcends traditional boundaries between physics, philosophy, and cognitive science. The book develops along two complementary paths. First, it explores quantum-like modelling, an exciting emerging field where researchers apply logical and mathematical structures from quantum mechanics and information theory to cognitive modelling and decision science. Second, it investigates the profound links between quantum science and consciousness studies, incorporating insights from advanced mathematical frameworks such as category theory. By synthesizing these two approaches, the authors propose a novel framework termed 'quantum-like reality' that moves beyond pragmatic modelling to offer deeper ontological thinking that can enrich both foundational understanding and applied research. This will be an interesting read for students and researchers working at the intersection of quantum physics, cognitive science, and consciousness studies.
The current chapter explores philosophical and mathematically inspired concepts of quantum cognition paradigm. Quantum cognition is an interdisciplinary domain of overlaps between quantum foundations or quantum information theory concepts and cognitive decision-making processes. The chapter explores frontier works which demonstrate that various quantum-like concepts can describe, explain and even predict human cognitive phenomena better than the standard cognitive science models. Again, no reductionism is implied, or we necessarily do not hold that mind is quantum physical for sure.
The mind–matter relationship remained in the domain of philosophers for aeons. However, the inquisitiveness of the scientific minds has always been trying to understand the science behind its various functions. The scientific temper ushered in by the Renaissance about the 15th century saw the scientists exploring this problem from a science point of view. Technological advances during the later part of the 20th century enabled neuroscientists to explore and localise functions of the brain. However, the most difficult has been understanding the origin of a conscious experience scientifically or materialistically. Despite the delineation of many functions of the brain, the origin of conscious experience, the qualia, in the material brain remains elusive, so much so it came to be called the holy grail of neuroscience. Heisenberg wrote: ‘Physics entered the domain of philosophy with the emergence of consciousness in quantum observation, which incidentally opened the door for reconciliation of science and philosophy’,[1] an event which enabled the predictions of Snow of the merging of arts and sciences.[2,3] Quantum mechanics is a branch of physics relating to very small particles – subatomic particles – electrons, photons, and everything in the submolecular realm, being the smallest units in matter. Quantum theory is the most fundamental theory of matter available at present. Some basic concepts of quantum physics need to be understood. These include “superposition”, where in subatomic particles exist either as waves or particles in a dual nature, never simultaneously. They exist as waves in more than one place at a time and once an observer observes or interferes with (such as measuring) their superposition state collapses to particle state. Quantum entanglement is the phenomenon that occurs when a group of particles which are generated, interact with or share special proximity such that they remain connected even when separated by vast distances. Consciousness is a manifestation of quantum process. Q mind or Q consciousness comprises a group of hypotheses proposing that quantum mechanical phenomena such as entanglement and superposition may play an important part in the functions of the brain and could thus explain the origin of consciousness. Several theories of quantum consciousness have been proposed. Wigner proposed the idea that quantum mechanics has something to do with the workings of the mind and proposed that the wave function collapse in the interaction with conscious observation creates consciousness.[4] Vitiello and Freeman[5] proposed quantum field theory (QFT) of brain states. This theory deals with systems and provides formal elements from which a standard description of brain activity can be inferred. According to QFT, particles are only excited states or simply manifestations of a field. Every particle has its own field that covers all of the universe, which means that, according to QFT, all of the electrons of the universe belong to the same field and could be regarded as one. Bohm formulated the QFT as a deeper theory of quantum theory plus relativity.[6] He viewed mind and matter as projections into our explicate order underlying the implicate order. Quantum brain dynamics (QBD) hypothesis explains the function of the brain within the framework of QFT.[7] It is not yet known exactly how quantum superpositions and their collapse result in the genesis of the raw feels of consciousness, the qualia. Feynman stated ‘if you think you understand quantum mechanics then you do not!’[8] Pribram proposed the holonomic brain theory (quantum holography). He invoked quantum mechanics to explain the higher-order processing by the mind. Pribram provided evidence on how much of the processes in the brain take place in a distributed fashion.[9,10] The composite model of Pribram-Bohm of holoflux hypothesis addresses observed phenomenon of non-locality both spacially and temporally. Bose and Einstein, who first predicted Bose Einstein condensate proposed that water at dendritic membrane surfaces might operate by structuring condensation,[11] supporting QBD. Penrose and Hamoreff proposed the orchestrated-objective reduction (ORCH-OR) in 1989 through 2013. According to them, the microtubules in the neurons (neurotubules), the tubulin protein polymer at the site of quantum collapse, leads to conscious experience. The quantum superposed states which develop in the tubulins remain coherent and recruit more superposed tubulins until a mass-time-energy threshold is reached. At this point, self-collapse or objective reduction occurs, which is equated to a discrete conscious event. Cascades of ORCH-OR events give rise to the stream of consciousness.[12,13] Penrose suggested that objective reduction represents neither randomness nor algorithmic processing but instead a non-computable influence in spacetime geometry from which mathematical understanding and, by later extension, consciousness derives.[14] Quantum vibrations in the microtubules proposed by Bandyopadhyay[15] have been shown to be source of conscious experience by corroborating the Penrose-Hemeroff’s ORCH-OR hypothesis.[13,16] In April 2022, the results of two related experiments at the University of Alberta and Princeton University, announced at The Science of Consciousness conference, provided further evidence to support quantum processes operating within microtubules. However, in another experiment, Gregory D. Scholes and Aarat Kalra of Princeton University used lasers to excite molecules within tubulins, causing a prolonged excitation to diffuse through microtubules further than expected, which did not occur when repeated under anaesthesia.[17,18] Beck and Eccles considered quantum mechanics at the synaptic level. If Orchestrated objective reduction (ORCH-OR) theory is applicable, a similar phenomenon in the microtubules at the presynaptic level, the axon terminal could be invoked for the genesis of consciousness.[19] A recent study by scientists at Trinity College, Dublin, in October 2022,[20] suggests that quantum processes underlie the cognitive and conscious brain functions. The brain–mind operational architectonics is the boundary between and integration point of quantum physics and eastern metaphysics and that it may inspire building a richer and more inclusive paradigm of the brain–mind relation, where quantum physics and eastern metaphysics are inherently intertwined. A body of empirical evidence[21-24] supports these possibilities, strengthening the proposal that the mind–brain relationship may be partially quantum. Quantum information theory clarifies the distinction between the unobservable mind and the observable brain and supports a solid physical foundation for consciousness research. With all these theories trying to explain and understand the theoretical/hypothetical framework for consciousness to explain the subjective experience of consciousness, the experts of this field feel it is still a long way to bridge the gap between current neurobiological and physical–mathematical concepts with their associated quantum–mind theories. Though there is still a long way to go for explaining conscious experience scientifically, when ever this happens, it will become one of the benchmarks in science. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Use of artificial intelligence (AI)-assisted technology for manuscript preparation The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the preparation of the manuscript and no images were manipulated using AI.
The question of whether quantum mechanical phenomena play a functional role in brain activity and the emergence of consciousness remains one of the most controversial yet intellectually stimulating debates at the intersection of physics, neuroscience, and philosophy of mind. This review systematically examines the principal theoretical frameworks proposing quantum-level mechanisms in neural computation, including the Orchestrated Objective Reduction (Orch OR) hypothesis by Penrose and Hameroff, the quantum brain hypothesis of Stapp, quantum coherence models in microtubules, and quantum field theories of consciousness. We critically evaluate the current state of empirical evidence—including recent quantum biology findings, the challenge of decoherence in warm, biological systems, and experimental observations of quantum effects in biological systems—alongside computational models that bridge quantum formalism and neural network dynamics. Furthermore, we discuss the implications of quantum cognition models for understanding perception, decision-making, and memory. Despite significant scientific skepticism, emerging evidence from quantum biology and advanced neuroimaging technologies provides tentative support for quantum processes in neural substrates. We conclude by identifying critical gaps in current knowledge and outlining future research directions that may resolve the debate, including proposals for experimental paradigms using quantum sensing technologies applied to neural tissue. This review aims to serve as a foundational reference for researchers across disciplines approaching the quantum mind hypothesis with scientific rigor.
This article considers a partly philosophical question: What are the ontological and epistemological reasons for using quantum-like models or theories (models and theories based on the mathematical formalism of quantum theory) vs. classical-like ones (based on the mathematics of classical physics), in considering human thinking and decision making? This question is only partly philosophical because it also concerns the scientific understanding of the phenomena considered by the theories that use mathematical models of either type, just as in physics itself, where this question also arises as a physical question. This is because this question is in effect: What are the physical reasons for using, even if not requiring, these types of theories in considering quantum phenomena, which these theories predict fully in accord with the experiment? This is clearly also a physical, rather than only philosophical, question and so is, accordingly, the question of whether one needs classical-like or quantum-like theories or both (just as in physics we use both classical and quantum theories) in considering human thinking in psychology and related fields, such as decision science. It comes as no surprise that many of these reasons are parallel to those that are responsible for the use of QM and QFT in the case of quantum phenomena. Still, the corresponding situations should be understood and justified in terms of the phenomena considered, phenomena defined by human thinking, because there are important differences between these phenomena and quantum phenomena, which this article aims to address. In order to do so, this article will first consider quantum phenomena and quantum theory, before turning to human thinking and decision making, in addressing which it will also discuss two recent quantum-like approaches to human thinking, that by M. G. D'Ariano and F. Faggin and that by A. Khrennikov. Both approaches are ontological in the sense of offering representations, different in character in each approach, of human thinking by the formalism of quantum theory. Whether such a representation, as opposed to only predicting the outcomes of relevant experiments, is possible either in quantum theory or in quantum-like theories of human thinking is one of the questions addressed in this article. The philosophical position adopted in it is that it may not be possible to make this assumption, which, however, is not the same as saying that it is impossible. I designate this view as the reality-without-realism, RWR, view and in considering strictly mental processes as the ideality-without-idealism, IWI, view, in the second case in part following, but also moving beyond, I. Kant's philosophy.
Introduction We saw in Part I that in addition to explaining consciousness there is another hard problem for the modern scientific worldview – understanding what quantum physics is telling us about reality. And if anything this one is harder. In philosophy of mind there is at least consensus enough for an orthodox position to exist (materialism), and a widespread expectation that it will be vindicated by future neuroscience. By contrast, in philosophy of physics all sides understand that quantum theory is compatible with a variety of metaphysical interpretations, and have little hope that new empirical discoveries will settle the matter. But both problems are “hard” in the sense that, despite tremendous intellectual effort over many decades, no clear progress has been made toward solving them. The basic idea of quantum consciousness theory is that bringing the two problems into contact may be the key to solving both (though I will be addressing only the mind–body problem in what follows). That this could be a novel idea attests to the fact that their philosophical discussions have evolved quite separately. While philosophers of physics have long been interested in the role of consciousness in the measurement process, they have engaged little with the mind–body problem per se; and philosophers of mind have been almost unanimous in dismissing the suggestion that consciousness has anything interesting to do with quantum physics. Social scientists might echo such skepticism, wondering how adding the problem of interpreting quantum theory to the problem of consciousness will help them . Besides piling up jargon and arcane debates, in moving to the sub-atomic level we are now even farther removed from the human world, and seemingly poised to engage in the most vulgar reductionism. Yet, naïvely one might expect the two problems to be related, for two reasons. The first is the intriguing analogies mentioned in Chapter 1 between the mental and quantum domains.