I've long suspected that the brain might be using quantum computing techniques. It's a good physically plausible explanation for how you can get more compute than a modern at-scale data center on 40-60W of power and in a volume about the size of two beer cans.
IMHO there's really only three possibilities:
(1) There exist ridiculously efficient learning, search, and other algorithms that have not been formally discovered that allow the brain to do what it does on a lot less compute than we think. P=NP would be the extreme case of this.
(2) The brain is a quantum computer or is doing something equally exotic.
(3) It's supernatural, and the brain is only like a radio receiver for something in another realm. (Or the universe is a simulation, etc., etc.)
There's a huge difference between molecule-scale quantum chemical phenomena (as in photosynthesis) and quantum computation. Finding the former in the brain would be very cool, but it wouldn't be terribly surprising or revolutionize cognitive science the way the latter would.
FWIW, the quantum nature of reality is harnessed by biological processes (see photosynthesis, for example[0]), and our attempts at modeling brains using classical computers have been remarkably inefficient, so far (compare the energy required by the server farm that simulates a mouse brain vs your metabolism).
I wouldn't be surprised if it turned out that cognition relied on quantum phenomena as well.
Ass far as we understand, out brains use quantum mechanics only as much as our processors use quantum mechanics already - the world is quantum mechanical, so our brains are as well.
However, given the scale of known brain features, the temperature of the brain, and other sources of noise, it's very very very hard to imagine how the brain could be a quantum computer.
This article is very exciting, it almost makes you wonder if the universe is set up to keep adding new possibilities to how much information can in theory be processed by biological systems... e.g. the brain. Anyway if this research is true it's incredible that nature has worked out such a clever hack.
I've not seen many other examples of biology using quantum states - given the article there must be quite a few I assume?
I don't see much discussion of quantum mechanics as being leveraged inside of neurons.
But I'm just not convinced chemistry is fast enough for thought to happen any other way than quantum.
Life has been far ahead of human state of the art for a long time.
Often, we don't even know what to look for until we learn basic physics ourselves.
For example, barely 100 years ago, we figured out that light is energy delivered in photon packets. Only then could we understand processes like photosynthesis. Something life figured out billions of years ago.
As we learn more about quantum mechanics, we discover that photosynthesis seems to harness quantum effects to improve conversion efficiency.
I'm convinced the brain is using advanced physics we don't fully understand yet.
Yet, that the brain and neurons are quantum is something I haven't seen much of in literature.
Once we figure out room temperature quantum computing, I wouldn't be surprised if we find that the brain has been doing it all along.
We just don't know what to look for, until we learn enough about physics ourselves.
Indeed, I'm suggesting the brain may do a kind of quantum computation, but the intrinsic knowledge a given brain has of models of biases toward risk/reward that resemble a father's behavior originate as genomic information modules from his genetic material, which the brain loads as models to do runtime computation about sensory stimuli on.
e.g. Consciousness is not some higher dimensional super or substrate, it's code, compressed into and transmitted by dna, running on a quantum computer in a brain, learning and processing according to initial weights in the dna model.
Do note that this article doesn't claim or mention that the brain is a quantum device. We have evidence that the mechanism of photosynthesis and possibly the magnetic-sensing cells of some animals are not explainable classical mechanics, and that's no big deal, we know that the classical mechanics is a rough approximation and QM is also required to explain why a bunch of chemistry works that particular way.
However, we don't have any reason to suppose that quantum computation is involved or relevant in any of the processes mentioned in the article, and we don't really have any evidence or reason to suppose that the brain is a quantum device. It might be one, but for all that we've seen until now it might as well be an electrochemical computer, that is sufficient to explain all observed phenomena.
Does anyone know if we understand enough about natural, generally intelligent brains to dismiss the idea that they are using quantum phenomenon for computation? Is it unlikely for any reason?
I don't believe that our brains are quantum computers, but I don't think we know enough about how the CNS works to completely rule it out. Quantum effects have been observed in living organisms [1], so the "it's a warm soup" argument is not sufficient.
I haven't found the original article yet, but from the summary: using a special MRI machine they found MRI signals that resemble heartbeat evoked potentials, a form of EEG signals. Apparently, these signals are only detectable if they are entangled. Hence the brain is a quantum computer.
That there are entangled particles in the brain is no surprise. Any cup of coffee will have a million. That the brain uses quantum computing is a bit of a reach it seems.
I’ve wondered recently whether the brain can be represented by a Turing machine if our computation mechanisms utilize something like back propagation through time via quantum effects.
Maybe we will make progress in our understanding this millennia :)
"Is it possible that brain is in fact a quantum computer?"
It's an interesting thing to ponder.
Quantum computing is still just another computational model, and it's main Advantage is that it involves non determinism. But non determinism, in and of itself, can be modeled by deterministic computer.
I think the biggest problem is that we don't understand what computation is taking place in the brain, or even if it is "computation" according to our current definition of the word. I think that this issue is the biggest problem in reconciling whether or not it is possible to accurately model the human brain.
It is still widely dismissed. And while coherence seems to be relevant for a particular stage of energy conversion in photosynthesis and also in allowing sensitivity to magnetic fields, the mechanisms for leveraging these are incidental. They are used passively to achieve an effect and not actively to perform computations as would be required for Penrose's hypotheses.
To claim the brain leverages quantum effects at biological scales is going far but still plausible. But to say that quantum computations are going on in the brain and are expressed at the level of thinking we acheive (evinced by claiming that we are not Turing machines), that is something that would require a lot of data to support (something that this theory sorely lacks). Much of what we know about quantum mechanics and neurobiology would have to be redressed. Indeed if such were true there would be indirect evidence - I expect we would find quantum mechanics, heck ordinary probability theory, more intuitive for example .
Far more interesting are the epigenetic like effects that occur in memory formation.
We do not know that actually.
While it might be true that classical mechanics is the only machine behind our brain, evolution is just as likely to have stumbled into a quantum computer design we have not yet discovered in the last billion years.
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