Do you think being asleep (without dreams) for 1 hour feels subjectively different than being asleep for, say, 12 hours?
Yes, in that I can subjectively tell that the duration is shorter for the first than the second. This is again very different to the experience of being under anesthetics, which seems to function, subjectively, almost like a time machine - the span is completely imperceptible. And I think this is a closer analogy to death than sleep.
I'm not sure it does. The only things that can have an influence in how we perceive the passage of time are objective external conditions like changes in light and temperature, after we wake.
Humans typically have an internal "biological clock" which, even if not consciously perceived, still allows them to wake as necessary.
But I'm also not sure I agree with the 'unfelt gaps' idea. Our consciousness doesn't feel like a continuous stream modulated by periods of lesser awareness (sleep, day dreaming). It feel like more of a 'stop and start' phenomenon.
This is not my experience. When I sleep, I still am cognizant of the passage of time, even if it is distorted; the only time I have ever felt a 'stop and start' is when I was put under (I've never been knocked out or passed out).
Also, I'm just curious, are you open to the possibility of reincarnation generally (or shift in subjective awareness between beings) with or without felt gaps @ExitStageLeft ?
Yes. What I am not open to is the transference of any material (souls, past life memories, etc.) between subjective awarenesses. I'd suggest that the
only thing which would continue under these circumstances is the fact of subjective awareness.
For example, if there is no 'self', and the mentality of biological systems is a connected bundle of memories, sensations, emotions, thoughts etc, without a metaphysical locus (the 'I'), then when that system dies, is there any logical reason why the (now defunct) awareness of that system couldn't 'shift' to a new nascent system (a new host) for the awareness to continue?
(though without the memory of the previous host, as memories, just like sensations etc, are isomorphic (but non-identical maybe) with specific neural states of specific systems)
I don't see why not. This is very different, again, from spiritualistic interpretations of reincarnation, karmic or otherwise. It suggests that all that continues is subjective awareness. And while I am not prepared to go so far as open individualism (which suggests that "I", or my field of subjective awareness, will experience itself as every sentient organism which has ever existed), I have no issue with the view that subjectivity continues.
The YouTuber
Kill(ss)ing Asuka produced an interesting video on a possible mechanism for this - the degradation of consciousness to a certain low level analogous to the same level as that of a fetus or an infant, so that the subjective awareness of one consciousness resumes in another. The "experience of nothingness", which cannot exist, is thereby avoided. (I have no idea why he's doing this without a shirt on, but nevertheless.)