[kipchak]

It seems like the brain "just" being a giant number of neurons is an assumption. As I understand it's still an area of active research, for example the role of glial cells. The complete function may or may not be pen and paper-able.

[thrance]

There are indeed many people trying to justify this magical thinking by seeking something, anything in the brain that is out of the ordinary. They've been unsuccessful so far.

Penrose comes to mind, he will die on the hill that the brain involves quantum computations somehow, to explain his dualist position of "the soul being the entity responsible for deciding how the quantum states within the brain collapse, hence somehow controlling the body" (I am grossly simplifying). But even if that was the case, if the brain did involve quantum computations, those are still, well, computable. They just involve some amount of randomness, but so what? To continue with grandparent's experiment, you'd have to replace biological neurons with tiny quantum computer neurons instead, but the gist is the same.

[sigmoid10]

You wouldn't even need quantum computer neurons. We can simulate quantum nature on normal circuits, albeit not very efficiently. But for the experiment this wouldn't matter. The only important thing would be that you can measure it, which in turn would allow you to replicate it in some non-human circuit. And if you fundamentally can't measure this aspect for some weird reason, you will once again reach the same conclusion as above.

[thrance]

You can simulate it, but you usually use PRNG to decide how your simulated wave function "collapses". So in the spirit of the original thought experiment, I felt it more adequate to replace the quantum part (if it even exists) by another actually quantum part. But indeed, using fake quantum shouldn't change a thing.

[Tadpole9181]

> The complete function may or may not be pen and paper-able.

Would you mind expanding on this? At a base read, it seems you implying magic exists.

[kipchak]

It could well be the case that the brain can be simulated, but presently we don't know exactly what variables/components must be simulated. Does ongoing neuroplasticity for example need to be a component of simulation? Is there some as of yet unknown causal mechanisms or interactions that may be essential?

[Tadpole9181]

None of those examples cannot be done on pen and paper or otherwise simulated with a different medium, though.

AFAICT, your comment above would need some mechanism that is physically impossible and incalculable to make the argument, and then somehow have that happen in a human brain despite being physically impossible and incalculable.