After returning from her vacation in Hawaii, your cousin apologizes for forgetting the time difference and calling while you were in a very deep sleep. You're very puzzled by her comment because you have no recollection of the phone conversation. The phone conversation most likely occurred while you were experiencing:
A) REM sleep.
B) paradoxical sleep.
C) beta brain waves.
D) stage 4 NREM.

Question

Quizplus · Accepted Answer

Stage 4 NREM sleep is the deepest stage of sleep, during which it is difficult to be awakened and people often have no recollection of events that occur during this time.

After Returning from Her Vacation in Hawaii, Your Cousin Apologizes