REM sleep normally occurs for the first time:
A) within 10 minutes of falling asleep.
B) after about an hour of sleep.
C) about 70 to 90 minutes after sleep onset.
D) after about 3-4 hours of sleep.
James has been sleeping for about 90 minutes when his brain shows rapid, irregular waves. His blood pressure rises, his heart rate increases, and his skeletal muscles go limp. Which of the following is the most likely conclusion?
A) James is chronically sleep-deprived and his sleep, like his daytime activities, is abnormal.
B) James is experiencing physiological changes that are normal for the third stage of sleep.
C) James is experiencing unusual sleep because during the day he engaged in strenuous physical activities.
D) James is experiencing physiological changes that are normal during REM sleep.
REM sleep has been called "paradoxical sleep" because:
A) the brain is very active, yet the body is entirely inactive.
B) the body is very active and restless, but the brain is very inactive.
C) the eyes are open, though the person remains asleep.
D) colorful dreams occur, in contrast to the black-and-white dreams of NREM sleep.
During the night:
A) REM sleep periods become longer.
B) delta waves increase.
C) dreaming decreases in frequency.
D) NREM sleep periods involve a more and more active EEG.