Quote Originally Posted by bro View Post
Honest question, because I don't know--> How do you then account for the successes of sleep deprivation in nearly instantaneously inducing REM sleep?
Also to add to the other answer you got, REM is usually prioritized by the body /before/ deep sleep, so you can fall into REM straight away no matter what time of day. The difficult part is waking up afterwards as you will immediately fall into deep sleep after. I know from experience after doing polyphasic sleep experiments. I would never dream during my longer naps, but my shorter naps would be pretty much all REM, and I would have some pretty freaky experiences.