[ben_w]

A brain is an electrochemical network made of cells; artificial neural networks are a toy model of these.

Each neurone is itself a complex combination of chemicals cycles; these can be, and have been, simulated.

The most complex chemicals in biology are proteins; these can be directly simulated with great difficulty, and we've now got AI that have learned to predict them much faster than the direct simulations on a classical computer ever could.

Those direct simulations are based on quantum mechanics, or at least computationally tractable approximations of it; QM is lots of linear algebra and either a random number generator or superdeterminism, either of which is still a thing a computer can do (even if the former requires a connection to a quantum-random source).

The open question is not "can computers think?", but rather "how detailed does the simulation have to be in order for it to think?"

[thfuran]

I think the real question is "How can we make a computer think without trying to fully simulate a brain?"