Take a gander at the OpenWorm project. It's a great example of how simple neuronal activity is (given details like the connections, number of receptors, and transmitter infrastructure). SOTA models of neuronal activity are simple enough for problem sets in undergraduate biomedical engineering programs.
Sure, to your point, we don't know. But the worm above (nematode) swims and seeks food when dropped into a physics engine.
My main point is that the scale of the human brain is well beyond the capabilities of modern imaging modalities, and it will likely remain so indefinitely. Fascicles we can image, individual axons we cannot. I guess, theoretically, we'll eventually be able to (but it's not relevant to us or any of our remote descendants).
Sure, to your point, we don't know. But the worm above (nematode) swims and seeks food when dropped into a physics engine.
My main point is that the scale of the human brain is well beyond the capabilities of modern imaging modalities, and it will likely remain so indefinitely. Fascicles we can image, individual axons we cannot. I guess, theoretically, we'll eventually be able to (but it's not relevant to us or any of our remote descendants).