I looked at this a few years back. I've always kept some hope that the Kurzwellian eschatology had some validity. You know, first we simulate a C.elegans and once that's done, it's only a matter of scale up before we can simulate a human and then boom singularity sky. And, really, how difficult is it to simulate a silly worm? after all the connectome is there, we know all the neurons and their connections, should be easy.
Well, when I looked at it I was shocked: it doesn't work! sure it could replicate some basic movements but many things that the stupid worm actually does where still a mystery. The docs didn't seem like people were close to figure it out either. And sure enough, a few years later seems like they gave up. And afaik that hyped European brain emulation project also folded in the midst of corruption allegations no less.
I think we don't understand any of this and we seem very far from it too. I think it's back to science fiction novels for a while.
> the connectome is there, we know all the neurons and their connections
No- each synapse has its particular neurotransmitters, and the distance, size, shape, number of receptors, and associated glial cells have very large impacts on transmission. The distance and thickness of axons also impacts the strength of signal delivered. That's all very hard to measure.
Neurons are also very sensitive to signal strength and timing. Eg inhibitory synapses work by opening holes in the cell wall, causing them to leak charge over time. You get that rate slightly wrong and it can hugely change the behavior of the cell.
The connectome is a bit like an untrained model of insane complexity, and each neuron has several weights that describe behavior over time as well as in direct response to signals. Without the weights it can't be emulated.
Well, when I looked at it I was shocked: it doesn't work! sure it could replicate some basic movements but many things that the stupid worm actually does where still a mystery. The docs didn't seem like people were close to figure it out either. And sure enough, a few years later seems like they gave up. And afaik that hyped European brain emulation project also folded in the midst of corruption allegations no less.
I think we don't understand any of this and we seem very far from it too. I think it's back to science fiction novels for a while.