We give a brief account on the existing strategies in quantum-mechanical approaching the problem of consciousness. To a list of distinguished approaches we add the next plausible notion: when treated quantum- mechanically, consciousness should be modeled as an open quantum system. This notion is tightly connected to the von Neumann's collapse (wave packet reduction). Here we strongly emphasize that the problem of the collapse cannot be resolved within the quantum mechanics of open quantum systems (or: decoherence theory). Some clues in this regard are briefly outlined.
We give a brief account on the existing strategies in quantum-mechanical approaching the problem of consciousness. To a list of distinguished approaches we add the next plausible notion: when treated quantum- mechanically, consciousness should be modeled as an open quantum system. This notion is tightly connected to the von Neumann's collapse (wave packet reduction). Here we strongly emphasize that the problem of the collapse cannot be resolved within the quantum mechanics of open quantum systems (or: decoherence theory). Some clues in this regard are briefly outlined.
An analysis has been performed of the theories and postulates advanced by von Neumann, London and Bauer, and Wigner, concerning the role that consciousness might play in the collapse of the wave function, which has become known as the measurement problem. This reveals that an error may have been made by them in the area of biology and its interface with quantum mechanics, when they called for the reduction of any superposition states in the brain through the mind or consciousness. Many years later Wigner changed his mind to reflect a simpler and more realistic objective position, expanded upon by Shimony, which appears to offer a way to resolve this issue. The argument is therefore made that the wave function of any superposed photon state or states is always objectively changed within the complex architecture of the eye in a continuous linear process initially for most of the superposed photons, followed by a discontinuous nonlinear collapse process later for any remaining superposed photons, thereby guaranteeing that only final, measured information is presented to the brain, mind or consciousness. An experiment to be conducted in the near future may enable us to simultaneously resolve the measurement problem and also determine if the linear nature of quantum mechanics is violated by the perceptual process.
There have lately been a variety of attempts to connect, or even explain, if not in fact, reduce human consciousness to quantum mechanical processes. Such attempts tend to draw a sharp and fundamental distinction between the role of consciousness in classical mechanics, and on the other hand, in quantum mechanics, with an insistence on the assumed exceptional character of the latter. What is strangely missed, however, is the role of human consciousness as such in the very discovery or creation of both of these physical theories. And this a priori role is far more important than all the possible a posteriori interplays between consciousness and the mentioned two theories of physics, interplays which may happen during one or another specific experiment, measurement, and so on. In this regard it is suggested that the specific features human consciousness may exhibit during interactions with quantum mechanical systems may as well have other explanations which do not appear to be less plausible, or less well founded.
Two principle concerns prompt some theorists to link quantum mechanics and theories of mind or theories of consciousness. On the one hand, it is commonly thought that conscious minds play some important role in processes of quantum measurement and that any good theory of mind ought to explain how a mind can play such a role. On the other hand, a few people think that the framework of classical physics is not, by itself, sufficiently powerful to explain the myriad remarkable properties of minds and that a good explanation must rely on some special features of quantum mechanics. Usually, these features include either state vector reduction-the collapse of the wave function-or special capabilities, often computational or super-computational ones, allegedly displayed by physical substrates while existing in hypothesised coherent states of linear superposition. Two questions summarise the author's misgivings about both the above motivations for linking quantum mechanics and theories of mind. First, does the process of quantum measurement really require a conscious observer? Second, does quantum mechanics underwrite any special effects in, say, intraneuronal protein lattices, which could play a role in instantiating consciousness in biological systems? It turns out that the particular character of the negative answer suggested for the first question also prompts a negative answer for the second. He summarises these negative answers after describing briefly some popular attempts to forge quantum theories of mind.
Abstract Does consciousness collapse the quantum wave function? This idea was taken seriously by John von Neumann and Eugene Wigner but is now widely dismissed. We develop the idea by combining a mathematical theory of consciousness (integrated information theory) with an account of quantum collapse dynamics (continuous spontaneous localization). Simple versions of the theory are falsified by the quantum Zeno effect, but more complex views remain compatible with empirical evidence. In principle, versions of the theory can be tested by experiments with quantum computers. The upshot is not that consciousness-collapse interpretations are clearly correct, but that there is a research program here worth exploring.
A variant of the von Neumann-Wigner Interpretation is proposed. Problems arising from the quantum Zeno effect are addressed as we have described previously. We do, however, offer some new, and perhaps unexpected observations. We are accustomed to thinking of wave function collapse as occurring consequent to laboratory measurements. We speculate that, whatever physical correlate of consciousness exists within the brain, it is quantum mechanical in the sense that a brain, left to itself, would eventually decohere into a state no longer compatible with its conscious functioning. Wave function collapse returns it to a state compatible with consciousness. Indeed, this may be its important reason for occurring. A universe without it simply could not play host to conscious brains. The fact that it also prevents us from encountering "absurd" situations in the laboratory is merely a fortunate dividend. Whenever a quantum measurement is made the universe's future history splits into a number of possibilities. This number may be very large or infinite. And we believe consciousness plays a vital role in this happening. A "conscious" universe where quantum measurements are being made allows for an enormous number of equally acceptable world-histories. An "unconscious" one, always evolving in a unitary fashion, allows for only one. If we assume that the decision as to which worldhistory is the real one (i.e. this one) is made at random we see that the universe is overwhelmingly more likely to be "conscious" than not.
A variant of the von Neumann-Wigner Interpretation is proposed. Problems arising from the quantum Zeno effect are addressed as we have described previously. We do, however, offer some new, and perhaps unexpected observations. We are accustomed to thinking of wave function collapse as occurring consequent to laboratory measurements. We speculate that, whatever physical correlate of consciousness exists within the brain, it is quantum mechanical in the sense that a brain, left to itself, would eventually decohere into a state no longer compatible with its conscious functioning. Wave function collapse returns it to a state compatible with consciousness. Indeed, this may be its important reason for occurring. A universe without it simply could not play host to conscious brains. The fact that it also prevents us from encountering "absurd" situations in the laboratory is merely a fortunate dividend. Whenever a quantum measurement is made the universe's future history splits into a number of possibilities. This number may be very large or infinite. And we believe consciousness plays a vital role in this happening. A "conscious" universe where quantum measurements are being made allows for an enormous number of equally acceptable world-histories. An "unconscious" one, always evolving in a unitary fashion, allows for only one. If we assume that the decision as to which worldhistory is the real one (i.e. this one) is made at random we see that the universe is overwhelmingly more likely to be "conscious" than not.