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Comment by saltyfamiliar | Hacker News Reader

That proportions in that analogy seem way off. Every single neuron of the human brain could be utilizing quantum mechanical effects at the same time. Not very much at all like a kid's sand castle against the world's tides. I don't think anyone really understand "thinking" and quantum mechanics well enough for the mechanisms to be apparent. I mean, squirrels convert forest detritus into general intelligence. I don't understand the strong certainty against the idea that there's some physics based piece of the puzzle that we're missing.

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Well, quantum computers are just fast but limited classical computers. So there is nothing actually very interesting to be gained by assuming that the brain could be a quantum computer isntead of a classical computer - at best, it would explain why the brain is more efficient at certain computations, but it can't explain how intelligence works.

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.

https://nautil.us/issue/47/consciousness/roger-penrose-on-wh...

> I don't understand the strong certainty against the idea that there's some physics based piece of the puzzle that we're missing.

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 it’s a strong conjecture that quantum effects at the single neuron level in the brain are significant. Given how evolution has had billions of years to operate and “train” itself, I don’t think it would be surprising to discover quantum-mechanical processes were deeply intertwined with intelligence.

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.

I have no opinion in either direction, but, I don't think nature discriminates in the usage of its tools based on the current understanding of humans.

> Every single neuron of the human brain could be utilizing quantum mechanical effects

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.

> squirrels convert forest detritus into general intelligence

Could you elaborate on this? Are you referring to a specific research result or waxing poetic?

I believe we've been able to model the processes behind neural firings for quite some time now, the issue is more mapping between that micro-scale understanding of how each individual piece in a 10^10 piece puzzle with 10^15 edges affects the macro-scale emergent properties of said puzzle. It's less a lack of understanding of the processes and more a complexity so great that it exceeds the grasp of our best modeling tools thus far.

We can barely model the humble nematode c. elegans with its 330 neurons.

Can we barely model it yet? I thought they weren’t at the point of getting able to simulate any actual work behaviours?

We can model neural activations but the whole-cell body simulation was still unstable last I checked (admittedly a year or so ago)

Does the modeled activity track any real world measurements, though? If we're going to claim any real veracity from a simulation then we need to crosscheck it against real measurements, right?

I believe they’ve attempted to measure synapse weights from real worms for training the net, the firings themselves are just basic electrochemistry.

'Attempted' implies 'not succeeded', though? And 'just basic electrochemistry' triggers a massive "is it, though?" response. Sure, we know what theory tells us, I want to know if observations align with theory.

Succeeded within what level of precision? The project is called OpenWorm, they have hydrodynamic models for macroscale cellular behavior and electrochemical simulations for modeling ion channels needed for the neural network. I don't have a reference handy but you should be able to find ample papers discussing accurate electrochemical modeling of synapses. The issue is that the models are complex enough that simulating a couple hundred neurons is expensive. As far as having accurate synaptic data so that they're simulating a specific worm rather than a random one pulled out of the æther, I believe that's still a work in progress.

Our biophysicalmodesl of neurons are actually woefully simplistic. https://journals.physiology.org/doi/full/10.1152/jn.00360.20...

Yes. The simple models are simple, the fast and large and useful models are simple. We have a lot of in vitro observations which can contribute to smaller, slower and more accurate models as your linked article mentions, observations which generally are ignored as being nth order effects when people are trying to make models which have a low enough computational complexity as to be useful.

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.

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