This is an important point. On the one hand real neurons are a heck of a lot more complex than a single weight in a neural network, so exactly mimicking a human brain is still well outside our capabilities, even assuming we knew enough to build an accurate simulation of one. On the other hand, there's no intrinsic reason why you would need to in order to get similar capabilities on a lot of areas: especially when you consider that neurons have a very 'noisy' operation environment, it's very possible that there's a huge overhead to the work they do to make up for it.
Since it is already giving interesting results, let's say a "brain" is a connectome with its current information flow.
Comparing AI with a brain in terms of scale is somewhat hazardous but with what we know about real neurons and synapses, one brain is still several orders of magnitude above the current biggest AIs (not to mention, current AI is 2D and very local, as the brain is 3D and much less locality constrained).
The "self-awareness" zone would need a at leas 1000x bigger, redondant, with a saveable flow of information, 3D with less locality, connectome that of the current biggest AI. Not to mention, realtime rich inputs/outputs, and years of training (like a baby human).
Ofc, this is beyond us, we have no idea of what's going on, and we probably won't. This is totally unpredictable, anybody saying otherwise is either trying to steal money for some BS AI research, or a the real genius.
