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’m also not a neuroscientist or a physicist though, so this is just my relative layman’s take.
0: https://www.the-scientist.com/infographics/infographic--quan...
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.
We can barely model the humble nematode c. elegans with its 330 neurons.
What is not missing is metaphysical quantum woo[0]. We can, have, and do observe how neurons and synapses function; the issue is that the computational complexity with current approaches is great enough to make complete neurological modeling of a microscopic worm with under a thousand total cells difficult.
[0] and even if you want to take those effects into account in your electrochemical models, all they do is turn them into stochastic models. there is exactly zero evidence of that randomness being of any real value to the thing we care about, which is the emergent macro scale properties of these systems.
To be clear, any quantum computation can be simulated on a classical computer, but it takes exponentially many steps. This is proven mathematically already, with the single exception that it's not proven that a better classical algorithm couldn't remote the exponential difference.
Yes, they are, in that neurons are made up of molecules which are held together and bind due to quantum effects. But that's the limit of it.
There is a missing piece of the puzzle all right, it's the huge role the environment and body play in developing intelligence. Everyone's focusing on quantum effects or just the brain forgetting that all they learn comes from the experience of the environment on the body.
The forces that shape and restrict life are the same that guide our learning process and evolution. We're looking too close to the brain and missing the big picture. Embodiment is the thing we're glossing over.
Quantum intelligence or consciousness seems like a detour, a blind walk into mysticism unless someone can prove there are things in neurology and AI that only make sense from a quantum perspective.
I think there is some definite upside to knowing the ultimate complexity of a single neuron.
Is it a detour? I don’t think we can say for sure either way until the question of how a single neuron works is settled.
Could you elaborate on this? Are you referring to a specific research result or waxing poetic?
By the butterfly principle, sand walls on the beach do alter the world's tides.
Quantum Biology: The Hidden Nature of Nature - https://www.youtube.com/watch?v=ADiql3FG5is
An Introduction to Quantum Biology - with Philip Ball - https://www.youtube.com/watch?v=bLeEsYDlXJk
As an amateur, my instinct is that the mystery of the observer "causing" wave function collapse is the best clue we have either way.
I wouldn’t be surprised if we are just weighted neurons, or if we do something quantum too. I doubt the something quantum will be the same as what our quantum computers do.
Source https://www.physicsforums.com/threads/does-consciousness-cau...
Quantum Biology: The Hidden Nature of Nature - https://www.youtube.com/watch?v=ADiql3FG5is
An Introduction to Quantum Biology - with Philip Ball - https://www.youtube.com/watch?v=bLeEsYDlXJk
I realize this isn't quite the answer you were looking for, but I thought it was worth mentioning.
I personally think this idea that there is some obvious categorical distinction between hard "physical" quantum phenomena and classically probabilistic ones is a fallacy. Quantum theory is in some sense just probability theory with more features.
More and more researchers are catching onto this and I think that's really exciting.
"Quantum" is turning out to have very little to do with how tiny or physical stuff is, and much more to do with assumptions about how observations emerge from interaction.
> rather than simply due to imperfect knowledge
That's the key right there... Quantum probability and quantum models don't rely on the existence of "perfect knowledge" or "underlying" objective states. States themselves are intrinsically probabilistic and contextually embedded. Measurements/observations cannot be cleanly decoupled from the states being measured, and are modelled as projections from a high dimensional space of possibilities onto some lower dimensional subspace.
This kinda thing works really well for social/cognitive systems which are incredibly sensitive to measurement process. For example, when conducting polls or surveys, the ordering of the questions is well known to impact the outcome. It turns out that this can be very well modelled using tools from quantum theory, and it has been.
Check out this book and all the books/papers citing it for a window into this fascinating world
And Von Neumann entropy is Shannon entropy, as applied to quantum states.
It would be like adding a classical computer we don't know how to turn on; it won't help anything if we don't know how to use it.
My gut feeling is that even if we use some probabilistic quantum compute it should be transferable to normal compute. Also animals vs human don't have enough difference to assume we are special.