I like the distinction between two "selfs." One is more like what Rousseau refers to, relating to the body as a whole. The second is more subtle, what the paper in the OP refers to as the center of consciousness, or the "I" that perceives. I remember from somewhere reading of Francis Crick's work on the "hard problem" of consciousness. A woman said to him that she didn't see the problem, that it was just like a TV in her brain. Crick replied "Yes, but who is watching the TV?"
Where in the brain is this "I"? There isn't a little fellow "behind the curtain" pulling levers and pushing buttons to move your hand or make you talk. That's the "self" that is the illusion. In my opinion it may be a bi-product of intelligence, an essential fiction for language perhaps, a way of avoiding having to say "My brain just indicated that it moved my hand" and other circumlocutions that make little sense.
It might be better to merely say, 'there are thoughts' than to say 'there is an I experiencing thoughts'. The latter seems to be illusory.
Most notably the notion that it's stable over time, that you are now the same person, albeit not in all ways, but in one supposedly fundamental sense, that you were 10 years ago, or even at a pinch 10 minutes ago. Some say self is just a story, that the brain tells to the brain, with a fictional protagonist. Perhaps memories are just like the brain reading back through previous scenes, to remind the brain of the coherence of the fictional narrative.
Most of us have at least a pretty stable, albeit probably still illusory, sense of self, but some people who suffer from certain types of identity dissociative disorder don't. They will report that they have no idea who they are or even that they feel they don't exist. It is as if, for them, all the pages of the storybook have been randomly mixed up or that the story is about someone else, or no one at all (that it has no protagonist).
Then there are multiple personality disorders, and we might ask, 'which of the persons is really real?' (possibly none of them, in the end).
It also seems that we can lose the self narrative after trauma, for example the cognitive depersonalisation that can happen during or after, say, childhood sexual abuse, the facts about which can also subsequently be excluded from or hidden from the self narrative.
And our sense of self can of course be moved outside our bodies entirely, as experiments and reports of various experiences show.
And most of us can do this in our imaginations.
Because I think we all probably experience such 'self-fluidity' to at least a limited degree, or can induce such things via, for example psychedelic drugs, which presumably temporarily interfere with the usual narrative in some way. We don't have to completely and permanently lose our self because of, say, dementia.
We can even routinely see things from a second-person perspective, when so immersed in a really good book that we stop thinking of ourselves as being merely the reader who is sitting in a chair reading. Then there's the state of mind called shock that we might enter after a very bad car accident, especially if there is also concussion. On other less traumatic occasions we can be temporarily disoriented for a variety of reasons, which can affect our sense of time, place and personhood.
And in all of those cases we are conscious. Obviously, and perhaps tellingly, our self vanishes completely when we are under full anaesthetic. Also when we are asleep, but not dreaming.
