The human mind in its totality, ie including consciousness, is a fundamentally different kind of machine to a computer. It's a machine, there is nothing supernatural here, and I am not invoking a 'god of the gaps' argument. However, like Roger Penrose, I think that our consciousness is not a computation for example. That kind of thing seems pretty key. If that is true, and what we call 'understanding' is a function of consciousness, then that's going to have implications.

It doesn't matter by the way, if Turing machines can't replicate human minds, why would we want that anyway? "Intelligent" systems that provide outputs and solve problems for us is what we want right? I think we'll have something that is, for all intents and purposes, "AGI", using classical computers. A 'philosophical zombie' in other words.