How often does rapid eye movement (REM) sleep occur in cycles?
A)About every 45 minutes
B)About every 90 minutes
C)About every 120 minutes
D)About every 150 minutes

Question

Quizplus · Accepted Answer

REM sleep accounts for 20% to 25% of sleep time and is characterized by desynchronized, low-voltage, fast activity that occurs for 5 to 60 minutes about every 90 minutes beginning after 1 to 2 hours of non-REM sleep.

How Often Does Rapid Eye Movement (REM) Sleep Occur in Cycles