I've only just heard of PCT, so I don't know if this is familiar to everyone already, or whether it's what the PCT people had in mind all along and I'm just the last to find out, but it seems to me that PCT explains, if not the how, then at least the why of consciousness. If all actions arise from errors against a model, then the upper layers of human decision-making would consist of a simulated person living in a simulated world, which is indeed what we seem to be.