
Stanton D. answered 07/01/20
Tutor to Pique Your Sciences Interest
Hi Asked,
your question implies, for an individual to choose to do this. Such extreme hallucination might be associated with impending death, use of certain drugs (but even there, some connection to the normal world persists), or as post-hypnotic altered perception. None of those are exactly "on-demand". Auto-hypnosis might enable this, but it would be extremely maladaptive, there might be no ability to return to normal consciousness at will. Additional possible causes, from iterature, include channeling another person's consciousness or existing in a time-shifted consciousness -- either time-displaced, at different speed, reversed, shifted in space-location perceived, etc.
-- Cheers, -- Mr. d. (the last time I knew, anyway!)