The problem of the observer in quantum mechanics is getting new human content. The paradox of Wigner's friend and its extended versions have observers who not only observe quantum phenomena, but communicate, have memories and even super-observer powers. Observers are represented by particle paths and state memories and advanced AI has been suggested to act as an observer. There is a new call for a solid theory of the observer in quantum mechanics. Two different branches of observer theories have emerged. The purely physical one is Heisenbergian, e.g. relational quantum mechanics where the observer is considered as any other physical quantum system. The other branch is psychologically rich as its observer has complex human faculties such as a mind, mental states and memory (Many minds), or the observer is considered as an active and experiencing agent, with continuously refreshed, scientific expectations (QBism). Is the human observer a special case, different from other quantum mechanical systems? Why is there no theory of the general observer in quantum mechanics? A historical summary is covered on how quantum mechanical interpretations have treated the observer, and the concept of hidden human variables is suggested to continue the discussion on the theoretical nature of the observer.
The problem of the observer in quantum mechanics is getting new human content. The paradox of Wigner's friend and its extended versions have observers who not only observe quantum phenomena, but communicate, have memories and even super-observer powers. Observers are represented by particle paths and state memories and advanced AI has been suggested to act as an observer. There is a new call for a solid theory of the observer in quantum mechanics. Two different branches of observer theories have emerged. The purely physical one is Heisenbergian, e.g. relational quantum mechanics where the observer is considered as any other physical quantum system. The other branch is psychologically rich as its observer has complex human faculties such as a mind, mental states and memory (Many minds), or the observer is considered as an active and experiencing agent, with continuously refreshed, scientific expectations (QBism). Is the human observer a special case, different from other quantum mechanical systems? Why is there no theory of the general observer in quantum mechanics? A historical summary is covered on how quantum mechanical interpretations have treated the observer, and the concept of hidden human variables is suggested to continue the discussion on the theoretical nature of the observer.
Introduction: the study considers the problem of observer’s status during specific quantum-mechanical experiments, in which the empirical result directly depends on the participation of the experimenter's mind. Here the problem arises of the connection between the mind of the observer and the quantum-mechanical description of physical reality. The paper pays attention to modern trends in physics and philosophy devoted to the study of this phenomenon. Some aspects of the philosophical interpretation of the mind as a quantum mechanism are presented. Materials and Methods: the research materials demonstrate an overview of several common quantum-philosophical theories. Attempts have been made to search for the connection of quantum phenomena with the mechanisms of the functioning of human mind. The experimental background of quantum physics is demonstrated, providing material for analyzing the possibility of applying modern quantum theory to the question of identifying the relationship of the quantum approach and describing the problem of the influence of the observer’s mind on the result of a physical experiment. Results: the concept of quantum mechanics, taking into account the latest achievements and results of physics, philosophy and psychology, allows us to consider the mind of the observer as an integral part of the mechanism responsible for the formation of the surrounding physical reality. The anthropic principle of participation considered in the work gives the observer's mind a special role allowing to form a quantum-mechanical description of physical reality. Discussion and conclusions: it is shown that the mind of the observer plays an important role in quantum theory. Moreover, mind as a psychic phenomenon may be in fact identical with the quantum-mechanical concept of choosing an alternative. Given the fact that the brain's thought processes influence the measurement results, it can be assumed that mind changes quantum probabilities. This assumption allows us to take a different look at the concept of reality itself.
Conceptual problems of the quantum theory of measurement are considered, which are embodied in well-known paradoxes and in Bell's inequalities. Arguments are advanced in favor of the viewpoint that these problems may hardly be solved without direct inclusion of the observer's consciousness in the theoretical description of a quantum measurement. Discussed in this connection is the so-called many-worlds interpretation of quantum mechanics proposed by Everett, as is the extension of Everett's concept, which consists in the assumption that separating the quantum state components corresponding to alternative measurements is not only associated with the observer's consciousness but is completely identified with it. This approach is shown to open up qualitatively new avenues for the unification of physics and psychology and, more broadly, of the sciences and the humanities. This may lead to an extension of the theory of consciousness and shed light on significant and previously misunderstood phenomena in the sphere of consciousness.
This paper offers a comprehensive analysis of Wigner’s Friend paradox (1961), a foundational thought experiment in quantum mechanics that highlights the tension between the internal perspective of a measuring observer (who experiences a definite outcome) and the external perspective of a super-observer who treats the entire laboratory as a quantum system in superposition. It traces the historical lineage from Schrödinger’s cat and von Neumann’s measurement theory, provides a formal mathematical description of the state evolution and logical structure of the paradox, examines implications for major interpretations of quantum mechanics (Copenhagen, Everettian many-worlds, QBism, relational quantum mechanics, and objective collapse theories), and discusses modern extensions such as the Frauchiger–Renner paradox. The work explores profound philosophical and epistemological consequences for the nature of observation, objectivity, intersubjectivity, and the role of consciousness in quantum theory (2026).
In collapse theories of quantum mechanics, there exist quantum observers who are observers being in a superposition of different result branches. In this paper, I analyze the mental state of a quantum observer. First, I argue that the mental state of a quantum observer is not the usual state of recording one of the results in the superposition, but it is definite. Second, I argue that the mental state of a quantum observer is determined by both the amplitudes and relative phases of the result branches of the superposition, and the mental content is composed of every result. Third, I argue that there are new mental properties which are lack for classical observers and determined by the amplitude and relative phase. In particular, the mental property determined by the amplitude may be a certain property of vividness of the mental content; the bigger the amplitude of a result branch, the more vivid the result is in the whole mental content. Finally, I argue that the new experience of a quantum observer, which violates quantum mechanics, implies that consciousness is not physically reducible or emergent but fundamental in collapse theories.
Quantum mechanics is often perceived as conceptually paradoxical because it appears to conflict with deeply rooted intuitions about fixed reality, determinism, and observation. This paper does not propose a new physical theory. Instead, it offers an epistemological reframing of quantum mechanics: not as a direct mathematical unveiling of a fully fixed pre-existing reality, but as a highly precise description of phenomenological structures emerging through observational conditions and interaction. The paper explores: the distinction between mathematical predictive success and ontological completeness, the role of human perception in constructing “fixed reality” intuitions, the phenomenological nature of qualities such as color and temperature, the possibility that some conceptual tensions in quantum mechanics arise from assumptions inherited from macroscopic cognition, and how quantum theory may be interpreted as describing observable structures rather than fixed hidden states. The work intentionally avoids mystical, anti-scientific, or consciousness-centric interpretations of quantum mechanics. It does not deny the existence of reality, nor reject modern physics. Rather, it attempts to clarify what exactly mathematical models are describing when applied to quantum phenomena. This text is positioned as a conceptual and phenomenological reorganization of perspective — a small doorway toward reconsidering how humans frame “reality” itself.
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.