If I wasn't an atheist I would have called out Thank God! when i read the following passages in Christof Koch's book, "The Feeling of Life Itself: Why Consciousness Is Widespread but Can't Be Computed."
Koch, who is President and Chief Scientist of the Allen Institute for Brain Science in Seattle, doesn't see any need to invoke mysterious quantum phenomena when attempts to understand consciousness are being undertaken.
As I noted recently, it irritates me when someone -- who almost always isn't a scientist -- tries to inject quantum theory into a discussion of meditation, consciousness, or such. As Koch says below, it is extremely unlikely (though not impossible) that quantum mechanics influences brain functions.
I'm enjoying Koch's latest book and will have more to say about it when I've read more of it. Here's what he had to say on the subject of quantum mechanics and consciousness.
That a conscious observer is required to convert the superposition of states of a quantum system into the single observable outcome has always troubled physicists. If QM [quantum mechanics] is really a fundamental theory of reality, it shouldn't need to invoke conscious brains and measuring devices. Instead these macroscopic objects should emerge naturally from the theory.
Many solutions have been proposed, but none have found acceptance. It is this dilemma at the root of such a successful theory of reality that has prompted Roger Penrose, a brilliant cosmologist, to propose a quantum gravity theory of consciousness that remains popular with the public.
Precious little evidence supports the idea that the brain exploits macroscopic quantum mechanical effects. Of course, the brain has to obey QM, as when photons of light meet retinal molecules inside photoreceptors. Yet the body's wet and warm operating regime is inimical to quantum coherency and superposition across neurons.
Today's quantum computer prototypes need extreme vacuum and temperatures close to absolute zero to avoid decoherence, when so-called quantum bits disentangle and become regular bits of classical information theory. That's why quantum computers are so difficult to build.
Furthermore, it has never been properly explained why phenomenological aspects of consciousness or its neurobiological substrate require quantum properties.
I see no need to invoke exotic physics to understand consciousness.
It is likely that a knowledge of biochemistry and classical electrodynamics is sufficient to understand how electrical activity across vast coalitions of neocortical neurons constitute any one experience. But as scientist I keep an open mind. Any mechanism not violating physics might be exploited by natural selection.