Assume that the many-worlds interpretation of quantum mechanics is true.

A classical computer that is modeled on the Turing machine is designed to perform exactly the same computation in each of the branching worlds.

But the brain is likely to have different patterns of electrical activity in each of the branching worlds.

Are there philosophies or philosophers that argue consciousness in the brain arise due to a superposition of the different patterns of electrical activity just before they decohere into the different classical worlds? If so, what are the main arguments put forth?

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    If consciousness is due to superposition before decoherence then what is the point of assuming MWI? Copenhagen is identical to MWI as far as anything that happens before branching. Indeed, unlike MWI, it even leaves something for the consciousness to do at least, see Does Consciousness Cause Quantum Collapse?, not that physicists find such speculations credible.
    – Conifold
    Commented Nov 15, 2020 at 22:53
  • I guess I'm speculating that consciousness appears at the quantum-classical boundary. Commented Nov 16, 2020 at 9:50
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    I think you have it reversed. MWI is deterministic, it produces a fully predictable multiverse, this is even touted as one of its advantages. On the other hand, the outcome of collapse in Copenhagen is unpredictable in principle, by an algorithm or even God, except for probabilities.
    – Conifold
    Commented Nov 16, 2020 at 10:15
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    @JohnEastmond Even classical computers would perform differently in some worlds. Relatively few compared to the different worlds where they would all give the same result, but still very, very many given the size and complexity of even the simplest of computers. Also, at quantum level, there is just no significant difference between a brain and a computer, at least not any that physicists would know of. Commented Nov 16, 2020 at 10:42
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    Copenhagen is incompatible with eternalism, and it does not predict a single future. There are multiple possible futures and which one is chosen is unpredictable. MWI has all possibilities realized, and so the future is fully predicted and can be viewed eternalistically. Your use of "determinism" does not seem to agree with the usual meaning of the word.
    – Conifold
    Commented Nov 16, 2020 at 20:04

4 Answers 4


But classical computers rely on quantum processes too, which underlie the function of semiconductors. You can't just say 'wooo quantum things are weird the brain is weird, therefore they are the same, woooo'.

"the brain is likely to have different patterns of electrical activity in each of the branching worlds."

Why? You are assuming brains are noisy & chaotic? Just like classical computers they take inputs, perform calculations, and give outputs, with errors & error correction. But, the way they do that is partly tbe result of evolutionary algorithms including one we call character/personality, ie there is a compounded result on the algorithm of a complex timeline. It is still deterministic (Many Worlds preserves determinism across the Many Worlds, it is only which world we find ourselves in that is indeterministic).

"Could consciousness in the brain arise due to a superposition of the different patterns of electrical activity just before they decohere into the different classical worlds?"

What would this explain?

I am a big fan of OrchOR, where the idea is quantum-coherent structures inside neurons, tubules, get linked up into qubit assembly, able to explore probability space or perform computations far more efficiently, especially of certain types like sifting for a match. But as I understand it, human consciousness arising that way does nothing to limit what computers can do, any more than the quantum processes in chlorophyll stop solar panels working. It's a result of efficiency, derived from selection pressures on small-scale organisms before large-scale organisms used the machinery.

Looking at strange loops it seems like there might be something about awareness, non-reactive expansion of the mind into the current moment, which allows explanatory layers & logical systems to form tangled hierarchies and use feedbacks, to go beyond what our computers can currently do, but I'd see that as a functional difference like the way convolutional neural networks have specific powers from their structure, rather than a magic essence that computers won't be able to simulate.


Are there philosophies or philosophers that argue consciousness in the brain arise due to a superposition of the different patterns of electrical activity just before they decohere into the different classical worlds?

I don't have an answer to the literal questions, just some observations about why such an approach may not make much sense.


Despite some old unproven speculations about microtubules in the neurons behaving coherently in a quantum way and influencing mind processes, there's probably not much difference, from the point of view of "quantumness" (or amount of "coherence"), between a classical computer and a human brain. So why evoke quantum to explain consciousness? (BTW, I'm not saying the human brain works like a, classical or otherwise, computer)


Whether we are physicalist or Cartesian about minds, it's safe to assume that consciousness of an individual supervenes at each moment on certain neurological configurations in her brain.

So, before even mentioning mind, consciousness, and all that stuff, we should rather make a step back and answer the simple question: what's a brain?

Despite the apparence, this is not much different from the question: what's a cat? (or a chair, or a tree). David Wallace [1.] remarks (I'm not quoting literally, and I hope not to have misunderstood the point) that in the Schroedinger cat experiment, just before opening the box, there is no cat in a superposition of states of being alive and being dead; rather, the state of the system is a superposition of two states which instantiate, respectively, a live cat and a dead cat. So, there are two cats in that system: one live cat, instantiated by a certain component of the state vector, and one dead cat, instantiated by a different component of the state vector. This is because what we call a "cat" (or any other object) is (a piece of reality that is approximately isomorphic to) a certain structure that we can read from the formalism: in this case a certain individual component of the state vector [plus probably various mathematical bells and whistles distinguishing it, such as a pointer basis, cause a vector of an abstract Hilbert space just by itself doesn't say much...]. A supersposition of such structures, we wouldn't call a cat... that's just not what a cat is.

The same goes for brains: at no moment one brain is in a superposition of having a certain configuration and a different configuration. There's just a state vector which is the sum of two components each instantiating a brain in its own different configuration. In particular, at no moment one brain is in a superposition of configurations that are supervened on by different mental states. So, in this sense, invoking MWI to explain consciousness may be moot.

[1.] David Wallace, The emergent multiverse. Quantum theory according to the Everett interpretation (2012)

  • I agree about the lack of fundamental dfferences between a quantum brain & a classical brain, as per my answer. But, I get tired of people dismissing OrchOR without even reading up. Penrose has contributed fundamental insights in quantum mechanics & relativity, to the point he now even has a Nobel Prize. What does it take to make people think, don't dismiss what he has to say out of hand? There's increasing momentum behind the idea quantum computation is the norm, rather than the exception quantamagazine.org/…
    – CriglCragl
    Commented Nov 17, 2020 at 13:30

Short Answer

According to WP: Many-minds interpretation:

The many-minds interpretation of quantum mechanics extends the many-worlds interpretation by proposing that the distinction between worlds should be made at the level of the mind of an individual observer. The concept was first introduced in 1970 by H. Dieter Zeh as a variant of the Hugh Everett interpretation in connection with quantum decoherence,2 and later (in 1981) explicitly called a many or multi-consciousness interpretation. The name many-minds interpretation was first used by David Albert and Barry Loewer in 1988.3

Long Answer

While my personal take is that this level of mathematical and logical physics is completely off the rails of empirical evidence, the whole notion of alternative physical realms and questions regarding what our naive realism hides from us, it certainly goes back to at least Platonic Forms and before by speculations of mythology and the pre-Socratics. Thus your question is tied into the heart of ontology and epistemology: what is our knowledge of reality and how do we know?

In regards to placing the locus of the source of multiple universes in the human brain, it shares an uncanny similarity to the Cartesian dualism regarding the pineal gland. From the latter article:

René Descartes believed the human pineal gland to be the "principal seat of the soul". Academic philosophy among his contemporaries considered the pineal gland as a neuroanatomical structure without special metaphysical qualities; science studied it as one endocrine gland among many.10

Now, instead of using a supernatural being to avoid causal closure, multiple-worlds interpretation seeks to put possible worlds and alternate universes in the brain somehow under the guise of quantum mechanics which is certainly home to some strange logic, so much so it has it's own quantum logic.

The general idea at play here is the many-minds interpretation. Ultimately, the devil is in the details, and like all simple theories, you have to read the positions of the various adherents to the philosophical thesis, which would largely be an intersection of philosophy of mind, quantum physics, and neuroanatomy in order to glean specifics regarding how exactly neural matter is responsible for relating decoherence and other physical realms.


Well... if you had a pet monkey with a typewriter as the author of the question above... or, OK, let's keep it real -- if the entire credit for it was going to the typewriter as the sole author -- then, absolutely! I'd say you had a clear winner in your proposal... even though it'd leave the actual brains kinda redundant.

UPDATE: despite its frisky style, the message above is dead-serious. QM can produce consciousness and the rest of reality down to the last photon particle. But it doesn't explain why it usually takes a human to write down a question. QM can make a lowly typewriter producing the greatest poetry of all times (and all worlds).

In other words, QM, rather than explaining things, suggests that we can stop looking for explanations. Which sounds terrific from the pure reason perspective, but, in practice, is just as useless (so, again, it is practical vs pure reason).

  • I wouldn't take it personally, because the truth I speak is not my own. Nor it is produced by the consensus in academia. There is ultimately only one source of the truth -- it is the objective reality itself. I'm but a messenger -- and you are not supposed to take my word for it. Just like you don't need to know the currier person, least having doubts in the letter's authenticity... you trust the seal, the envelope, not the messenger, Commented Nov 17, 2020 at 4:31

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