Science journalist and author Anil Ananthaswamy has written a thoughtful piece at New Scientist on the leading models of consciousness and their relationship to quantum mechanics (quantum physics). Are we reaching the point where we can test at least one of them?

Ananthaswamy is well qualified to assess the arguments. He is the author of both Through Two Doors at Once (2018) on quantum physics and The Man Who Wasn’t There (2015) on the nature of the self.

Models of consciousness that assume that “consciousness isn’t separate from the material reality that physics explains” (materialist or naturalist theories) fall into three general classes, as he explains.

Analysts like Tufts philosopher Daniel Dennett and Princeton neuroscientist Michael Graziano argue that consciousness is simply a model of the world created by the brain. Thus explanations are not needed. We rather need to understand the mechanics. As Graziano puts it, “When an information-processing device such as the brain introspects, or accesses internal data, and on that basis arrives at the conclusion that it has a magic property inside of it, the first question for a scientist is probably not: how did that device produce magic? Or even: what is the magic? Such questions are probably not coherent. Instead, in my lab we are asking: how does a brain arrive at that kind of self-description? ”

Many researchers are not happy with this approach because it begs a key question. An “information-processing device” doesn’t introspect, so far as we know. The rise of introspection is part of what we are trying to explain. So, assuming that we should be trying to understand the system as an information-processing device is not self-evidently helpful.

The focus is now on the quantum level of the universe

Many of these researchers look to quantum mechanics for answers. Ananthaswamy examines whether the superposition of quantum states might offer a materialist account of consciousness:

Quantum systems can exist in a superposition of all possible states simultaneously, and classical reality emerges when this superposition collapses into a single state. One idea is that this happens when the mass of a quantum system crosses a threshold. According to theoretical physicist Roger Penrose at the University of Oxford and anaesthesiologist Stuart Hameroff at the University of Arizona, consciousness emerges as the result of such collapses occurring in the brain. In their…

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