Which way does causation proceed? The pattern in the material world seems to be upward: particles to molecules to organisms to brains to mental processes. In contrast, the principles of quantum mechanics allow us to see a pattern of downward causation. These new ideas describe sets of multiple levels in which each level influences the levels below it through generation and selection. Top-down causation makes exciting sense of the world: we can find analogies in psychology, in the formation of our minds, in locating the source of consciousness, and even in the possible logic of belief in God.
Which way does causation proceed? The pattern in the material world seems to be upward: particles to molecules to organisms to brains to mental processes. In contrast, the principles of quantum mechanics allow us to see a pattern of downward causation. These new ideas describe sets of multiple levels in which each level influences the levels below it through generation and selection. Top-down causation makes exciting sense of the world: we can find analogies in psychology, in the formation of our minds, in locating the source of consciousness, and even in the possible logic of belief in God.
As generally accepted, consciousness or mind and material brain are closely related to each other; but how? Quantum mechanics is a new pathway to understand the hard problem of consciousness and its relation to the brain. Consciousness has specific properties such as unity, irreducibility, non-locality, etc. The completely different features of classical physics (locality, reducibility, determinacy, etc.) hindered the success of scientists to study consciousness. But quantum mechanics with its features (non-locality, irreducibility, indeterminacy, etc.) gave scientists hope to study consciousness. Several quantum approaches to consciousness have been proposed in recent decades; the most important point about these approaches is that each one has used its own philosophy to determine its viewpoint about the mind’s nature and even its quantum approach. In general, all scientific theories are based on some metaphysical principles which come from the worldview of scientists. In this article four contemporary approaches are discussed: The Eccles-Beck, Stapp, Penrose-Hameroff, and Avicenna-Bohm theories; philosophical and scientific points are highlighted for each of them. Finally, the theory of Top-Down Causation is discussed because we think it can provide a fertile philosophical ground for theories of “mind-brain relation” and “quantum consciousness”.
The nature of emergence of complexity out of the underlying physics is a key issue in understanding the world around us (1). Genuine emergence can be claimed (2⇓–4) to depend on top-down causation, which enables higher emergent levels to direct the outcomes of causation at lower levels to fulfill higher-level causal requirements; for example, the needs of heart physiology at the systems level determine gene expression at the cellular level via gene regulatory networks (5) (Fig. 1). However, the idea of top-down causation has been denied by a number of commentators (e.g., refs. 6 and 7). The paper by Aharonov et al. (8) makes a strong contribution to this debate by giving quantum physics examples where top-down causation manifestly occurs. This physics result has strong implications for the philosophical debate about whether strong emergence is possible. Indeed, it gives specific examples where it occurs in a remarkably strong form.
Fig. 1.
Bottom-up and top-down causation from the quantum level up to the organism level and down again. Adapted with permission of Royal Society, from ref. 5; permission conveyed through Copyright Clearance Center, Inc.
Now, the word “causation” is regarded with suspicion by many philosophers of science, so to characterize what is happening one can perhaps rather use a number of different descriptions such as “whole–part constraint” or “top-down realization.” The key point remains the same, that higher levels can influence lower-level outcomes in many ways, and hence explain how strong emergence is possible. This occurs across science in general, and in physics in particular (3, 4). The latter point …
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This note was written by a theoretical physicist currently working on physical aspects of consciousness, mind-matter relationships, and mind-body interactions. My purpose here is to inform the readers of this journal, in not too technical terms, of some recent ideas relating quantum mechanics, gravitation, and psychological phenomena. Attempts to relate the nature of consciousness to quantum mechanics have been known almost from the be+g of quantum mechanics. For an extended discussion and earlier references see, e.g., Stapp (1982). The common thread of the majority of the suggested hypotheses linking consciousness to a quantum level of description is a drawing of a between the spontaneous localization of mental patterns and (spontaneous or induced) reduction of the wave function in quantum mechanics. The latter essentially means that quantum systems are inherently described in probabilistic terms and any external observation reduces the manyfold of all potential possibilia to a single given realization. Interpretation of this process is one of the most difficult and controversial topics of quantum mechanics since in quantum mechanics it is thus far essentially impossible to demarcate unambiguously the observer from the quantum system itself. Despite that gravitational effects are usually deemed to be too weak at atomic level, a few authors recently discussed gravity as an inherent route used by nature to achieve an automatic spontaneous reduction of the wave functions of extended objects. In his recent book, Roger Penrose (1989) looks for the possible connections between consciousness, quantum mechanical reduction and gravitational phenomena. To simplify, the essence of these hypotheses is that subtle gravitational effects at the atomic-molecular level lock the brain into a particular mental state, thereby providing the materialization of the potential (quantum) mental image by the route similar to the reduction of the wave function in quantum mechanics. Isotopic diversity of chemical elements can substantially contribute to this picture, as well as to life processes in general (Berezin, 1988). Since gravity is a mass-sensitive effect, the fact that different stable isotopes of the same element (e.g., carbon, oxygen, nitrogen) have different atomic masses may affect the path of mental processing.
We show that several interpretations of quantum mechanics admit an ontology of objects and events. This ontology reduces the breach between mind and matter. When humans act, their actions do not appear explainable in mechanical terms but through mental activity: motives, desires or needs that propel them to action. These are examples of what in the last few decades have come to be called "downward causation". Basically, downward causation is present when the disposition of the whole to behave in a certain way cannot be predicted from the dispositions of the parts. The event ontology of quantum mechanics allow us to show that systems in entangled states present emergent new properties and downward causation.
The study examines a problematic hypothesis of possible approaches to identifying the quantum physical foundations of the functioning of consciousness. The authors proceed from the fact that in modern conditions, not a single science, nor all sciences taken together, gives a final answer to the question of the “mechanism” of the origin of thought. However, this does not mean at all that research in this direction needs to be stopped. The authors express confidence that modern and subsequent research into the “quantum concept of consciousness” will lead to the identification of previously unknown patterns, opening the way to the formation of new principles and approaches. As an example, the corresponding Penrose - Hameroff concept is considered. Quantum mechanics complements the tools of neurobiology and other branches of neuroscience, which together form an interdisciplinary field of knowledge that is dynamically growing and developing. The authors are not apologists for the omnipotence of quantum physics. Quantum correlates of consciousness actually mean that it is not today’s quantum mechanics itself that explains the emergence of mental states, but the fact that in the birth of these states it is essential that in the very process of the formation of neurodynamic impulses in the neurons of the cerebral cortex that generate mental states, there are processes of quantum nature. It should also be recognized that the quantum-molecular level (nanolevel) of processes in the neurons of the brain really exists and it is this that is the source of proto-consciousness. Science strives to move forward, new research programs are emerging within the framework of quantum biology, quantum psychology, quantum information science, which in turn can shed light on the hypothesis of the “quantum concept of consciousness.”
A number of modern scientists adheres to the point of view that, despite the fact that quantum mechanics does not allow to explain the existence of mental phenomena in the physical world, with the help of its inherent ontological principles and mathematical formalism, it is possible to understand the functioning of consciousness and the unconscious. Based on the analogy between quantum and mental processes, the unconscious can be represented as a superposition of mental states, and consciousness — in the form of decoherence of unconscious experiences. From an evolutionary point of view, consciousness can be considered as a consequence of the accumulation of a sufficient amount of information during the interaction of the organism with the surrounding environment, when the transition from the quantum state of the unconscious to the classical state of consciousness is carried out at the psychic level of being, by analogy with the accumulation of a sufficient amount of information by a quantum system during interaction with the environment, when at the physical level of being the collapse of the wave function. In psychotherapy and psychodiagnostics, one can see an analogy with the measurement process in quantum mechanics and a quantum leap from one mental state to another. However, the analysis of this point of view carried out in the article shows that the parallels between quantum mechanics and psychology today look insufficiently substantiated, since the mathematical model of the psyche, which allows describing human behavior on the basis of the laws of quantum mechanics, has not yet been built, which is why, firstly, the use of quantum-physical terminology in the understanding of mental experience does not rise to the level of scientific theory, remaining a metaphor, and, secondly, quantum psychology has a predictive potential, in contrast to the psychology of the classical type.