Question

The difference between stage 3 and stage 4 sleep is that during stage _____ sleep, __________ waves occur more than 50 percent of the time.
A.
3 . . . delta
B.
4 . . . delta
C.
3 . . . alpha
D.
4 . . . alpha

Answer 1

These are things you should just really know, can't explain. In stage 4 sleep, delta waves occur more than 50% of the time.