<i>&gt;Replicating functioning of the brain, or some major subsystem of it, is no doubt going to require far more than just billions of parameters.</i><p>Maybe, but we shouldn&#x27;t forget that computers do not suddenly lose their capability to function as exact, deterministic, programmable machines just because they happen to run an ANN.<p>What I mean is that there may be shortcuts to reduce the number of required nodes dramatically.<p>If you take the state of an ANN after it was trained to perform some specific task, you can ask the question whether there is a simpler function, i.e. one with much fewer parameters, that approximates the learned function.<p>Sort of like a human with the Occam&#x27;s razor gene. I think the fact that the number of neurons does not correlate perfectly with intelligence in animals is an indication that there is room for optimization.