While it's certainly possible that neural networks involve some non-trivial quantum-mechanical effects, it's also much more likely that (in the context of the brain), this notion arose from people expecting the brain and consciousness to be mysterious and inscrutable, hence "maybe consciousness is quantum!". In the absence of a concrete theory and testable experiment, that sentence has about as much meaning as "maybe consciousness is emergent!" or "maybe consciousness is supernatural!".

(Here, I'm talking about vague statements like those, or sci-fi theories like those in a Stephenson novel, as opposed to actual analysis like that of photosynthesis in the linked article.)

Wouldn't the presence of quantum effects be the default assumption, and there would have to be some compelling reason for their absence? It's not like nature started from Newtonian physics. Natural selection uses whatever it can get its sticky mitts on. Quantum effects are perfect for information processing.

To me, it's not the inscrutability of the brain that makes this seem likely... it's the bare knuckled win-at-all-costs no-holds-barred nature of natural selection.

One disambiguation: everything involves the presence of quantum mechanics, insofar as Newtonian physics isn't how the universe actually works. It's not entirely obvious where to draw the line here in calling an effect "quantum" or "not quantum"; Newtonian physics alone doesn't explain the majority of chemistry or electricity, for instance, and the body wouldn't function without a wide variety of chemical and electrical reactions. The brain (and absolutely everything else) runs on the actual physics of the universe, not on a model we might have of it.

The default assumption would be our current model of how the brain works; any model proposing effects (quantum or otherwise) not yet accounted for would require an appropriate amount of additional proof. When I suggested which seemed more likely, I was taking priors into account.

More generally, though, I wasn't referring to concrete models that make specific claims about how the brain works; I was referring to the rather frequently stated vague claims that use "quantum" in a way that would have no more or less meaning with the word "magic" substituted. A specific concrete model would be amenable to prediction and experiment.

Whether any particular such concrete model seems probable or not would depend on what it claims. For instance, a claim that the brain depends on macroscopic quantum effects at a far larger scale than observed elsewhere seems improbable; a claim that the brain depends on properties of chemical or electrical interactions that quantum mechanics explains better than other physics models seems relatively less improbable by comparison, depending on the details. Whether any particular claims seem probable or improbable would depend on our current understandings of quantum mechanics, the brain, evolutionary search processes, and so on.

What's a trivial quantum mechanical effect? Do orbital mechanics, wavefunction energies, count as trivial or nontrivial?

Yes, look into Stuart Hameroff, https://en.wikipedia.org/wiki/Stuart_Hameroff who thought of quantum effects through neural microtubules independently of Roger Penrose in 1987 whose work from 1989 inspired Neal Stephenson. Neal wrote on his website in the Acknowledgements section:

"1. Penrose posits, in The Emperor's New Mind (ISBN 978-0192861986) and Shadows of the Mind (ISBN 978-0195106466), that the human brain takes advantage of quantum effects to do what it does. This has been so controversial that I have found it impossible to have a dispassionate conversation about it with any learned person. The dispute can be broken apart into a number of different sub-controversies, some of which are more interesting than others. The science-fictional premise of Anathem is based on the relatively weak and modest assumption that natural selection has found some way to construct brains that, despite being warm and wet, are capable of exploiting the benefits of quantum computation. Readers who are uncomfortable with the specific mechanism posited by Penrose might also wish to read Henry Stapp's Mind, Matter, and Quantum Mechanics (ISBN 978-3540407614) which posits a quantum brain mechanism that is completely incompatible with Penrose's."

Also read this, I was lucky enough to do an academic level course on parapsychology long ago with Dick Bierman for 4 study points:

* Quantum States In The Retina? Pierre St. Hilaire, Dick Bierman, Stuart Hameroff http://quantum.webhost.uits.arizona.edu/prod/content/quantum...

Why is research like this not funded and practised more? Is it to far out, costly or difficult?

My cynical prediction is that if quantum-effects are part of the brain, it will only be in a practical, philosophically-boring way.

So they may be essential to basic plumbing shared by many species, but not otherwise a game-changing factor for "consciousness" or "intelligence".

Perception in humans seems capable of grasping data sets with billions of pieces of information each second, and distilling it all down to intuition.

All this information is serialized onto pretty much 5 channels (excluding things like one's sense of balance, or the awareness of how your body is posed), all streamed concurrently.

Sounds like a recipe for high bandwidth consumption. Many cycles per second.

Based on this, I'd wager we (and our perception of self) only exist in the ether between our body's neurons.

> All this information is serialized onto pretty much 5 channels

Says who? Just because you can invent categories doesn't mean you've identified channels. That would be like walking up to a computer, say "pictures, sounds, storage", and assume that the computer must contain 3 enormous channels dedicated to each type of information.

5 channels? those are some whooping-ass channels.

Each 'channel' (assuming he means senses) has a helluva bus width.

Moreover, we have more than five senses. An example of one of these, for this we have the real "devices"

https://en.wikipedia.org/wiki/Vestibular_system

built-in to give us the sense of balance:

https://en.wikipedia.org/wiki/Sense_of_balance

For example:

Masgrau et al. (2006) Atomic Description of an Enzyme Reaction Dominated by Proton Tunneling

http://sci-hub.cc/10.1126/science.1126002

Tha's what Roger Penrose argued in "Shadows of the Mind" where he theorizes about quantum effects in the human brain and how they might give rise to conciousness [1]. There's some criticism about it, because the brain is pretty warm and decoherence should disturb all quantum states so much taht they become unusable, but it is still a research topic if "warm" quantum states can exist.

[1] https://en.wikipedia.org/wiki/Shadows_of_the_Mind

The novel was based on Penrose's Earlier book I believe.

It's an excellent book that takes you on a trip through a couple millennia of development of thought in philosophy and physics, all presented in an accessible and entertaining way. Highly recommended.