Can you point to a single neural structure discussed by Penrose that isn't present in, say a flatworm? Are the neurons of "simpler" organisms fundamentally different from ours?
Evidently, the non-computable effect is what is missing according to Penrose. The excerpt is repeated below, emphasis mine:
OK, I'm going to ask again. Is there a structural difference between human neurons and those of other animals? I don't see how the axiomatic assertion that animals don't have consciousness implies that the structures enabling consciousness in humans somehow behave differently in animals.