Thread: Question about the REM cycle.

The main DV site has a good overview of sleep stages:

http://www.dreamviews.com/sleepstages.php

One thought, though: Clinically, REM sleep is generally not referred to as "Stage V" sleep (at least not in the lab I worked in, or in the literature I read), as it is not just a step beyond Stage IV sleep. In fact, it's almost the opposite of deep-stage sleep: The brain activity during REM sleep looks almost identical to waking brain activity. The only easily-observed difference is that, while the eyes display definite EMG (muscle) activity, the rest of the body is normally still and the mandibular muscles are tetanic. Breathing and heart rate become more erratic as well. Because of this mix of wake and sleep indicators, REM sleep is commonly called "paradoxical sleep." If you check into this, of course, you will probably find a lot of references to "Stage V/REM" sleep, but this is just my experience.

Most people hold fairly closely to that outline given on the link above, unless they're having sleep disruptions from snoring or something. Snoring screws your sleep stages up badly.