Roger Penrose more than 10 years ago said this was how it worked.  I have spoken/thought about this before I knew Penrose thought of it but Penrose obviously put the meat to the bone.
It’s been obvious to me for some time that the brain is a quantum computer.  For me the reasons are the following:
1) After 30+ years of trying to build learning machines we are basically still not even at the chicken level of intelligence or learning.
2) After 40-50 years we have not identified what brain EEG patterns represent, how the brain stores memories, how it pattern matches against memories, how it learns things other than a gross idea that somehow neuron firings seem to be potentiated at synaptic junctions.
3) It is clear that even with billions of neurons there is no clear way the brain could store the vast amount of sensory information or even the summarization conceptualization of all the information it gets in the neuron system that has been proposed.   It just doesn’t seem quanitfiably possible.
We have no idea how memories are stored in the brain.  I mean the actual memories or concepts or whatever.  The model proposed of the synaptic potentiating is a crude way decisions could be made but it doesn’t describe how the actual memories are stored, i.e the actual sensory inputs which must be matched.  Over a lifetime of vast inputs millions of sensory inputs/second there is an unbelievably large storage capacity and recognition capability but we’ve never found the hard drive.  How do you have a computer without the hard drive?  How do you say you understand anything about a computer if you don’t know where the hard drive is?
4) There has been no obvious mechanism of pattern matching clearly needed that has never been located or described how it could work.  One author I read who studied the brain said it was just a pattern matching machine.  I agree 90% of what the brain does seems to be explained and understood as having to do this.  However, nobody has been able to show how the brain could possibly do this.
5) When we think it happens in leaps, i.e. we don’t think linearly.  Our brains seem to operate more like the decoherence of a wavefunction and collapse to an idea rather than some logical process of a, b, c.
6) studies have shown that anesthesiology which suppresses consciousness works by suppressing microtubules in the brain
7) It is obvious to me that animals and even cells exhibit neural capabilities that are beyond our ability to explain.  Individual cells are able to learn and react to stimuli.  If you look at animal behavior it is clearly creative and not automatonish.  They are not stupid machines.  They have feelings and react in many cases intelligently.  They can be trained.
8) we have discovered that plants take advantage of quantum effects at high temperatures to improve the efficiency of capturing photons from the sun to use to power photosynthesis.  Using molecules called clorophores they are able to create a superposition of the electron to transport single photons.
9) More recently a study showed that birds who migrate when subjected to a magnetic field too small to move a single iron molecule were completely unable to fly along their paths.  When the magnetic field is turned off they can go again.
10) Quantum properties have been identified in mircrotubules of the brain this year
11) I have had dreams where the complexity of the entire dream is as if it had been planned far in advance requiring active planning in advance of the events in the dream even though they seem to happen spontaneously in the dream.
All of these things have led up to this year a conclusion that the operation of the brain as a quantum computing machine to my mind has been proved.
This is amazing because the brain consists of billions of neurons, operating at room temperature and sometimes well above in a wet environment theoretically very difficult for quantum effects to be sustained for any period of time but it now appears clear that evolution has been able to use quantum computing all along from the plant times.  It is therefore hard to understand how people would resist the obvious idea that nature has evolved to use molecules, atoms, DNA to fabricate quantum machines that leverage quantum effects.
The article is very detailed in how Penrose proposes this works although it is still missing key pieces but it moves the ball forward dramatically.
It is now clear that brain waves and the patterns we see are results of the decoherence and Penrose even is able to calculate some frequencies that match results we have observed.
This explains for instance the improvement in intelligence observed from meditation.  Meditation or calming the brain seems to slow the beating of the brain and bring more coherence.  In Quantum physics what this means is that the neurons ( or microtubule components ) are able to stay in a state of superposition longer and thus able to make more powerful pattern matches and optimizations.    This is logical.  I have never understood why slowing the brain would increase intelligence.  I could never understand how quieting or meditation could possibly affect brain performance.  Now we understand that anything that can lengthen the time of superposition the more the quantum magic can happen.  The more states that can be searched.
So many people have attacked Roger Penrose who in my opinion is one of the undisputed geniuses of our time.  He has done things like prove the existence of Black Holes with Hawkins, contribute Spin logic to mathematics and other amazing mathematical discoveries.  Spin Logic is the basis for a new unification theory that creates quantization of space as well as the forces.   This seems to me the most likely way that a unified grand unified theory will be created.  He has contributed the mandelbrot to art and physics and mathematics and many other things.  He has worked with Feynman and others on creating Penrose diagrams important for representing events in spacetime.
This guy is probably smarter than Einstein and he thinks its proved.  I think its proved as well.  It has to be.  However improbable something seems if it is the only way it could be done it must be the way it works.  The brain was unexplainable before.  This brings the possibility of understanding how the brain could possibly do what it does.
COnsider that for $10M you can buy a DWave computer with 500 qubits.  The human brain consists of billions of neurons each with who knows how many qubits but probably way way way more than 500.  We are saying the human brain has the quantum computing capability at least a  trillion times the speed of the DWave which recently was shown to be 5,000 times faster than networks of thousands of traditional computers at pattern recognition.
The brain is truly an awesome machine we can now see we are a long way from building a machine capable of being competitive with a human brain.   That’s reassuring as a human that we aren’t likely to be replaced by machines anytime soon.  I worried about that in the early days of AI.  This discovery makes me feel like at least it will be a long time before we humans are disposable by the machines.