This is no humbug: anesthetic agent-induced unconsciousness and sleep are visibly different.
Chamberlin
Nancy L
NL
Eikermann
Matthias
M
D000777:Anesthetics / Q000494:pharmacology; D054810:Deep Sedation / Q000379:methods; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D015742:Propofol / Q000494:pharmacology; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D014474:Unconsciousness / Q000139:chemically induced / Q000503:physiopathology*
D000777:Anesthetics; D015742:Propofol