Pieter was lying on the couch and had fallen asleep when all of a sudden his body jerked, and he woke up because he felt like he was falling. Pieter was most likely in which stage of sleep?

Which of the statements about night terrors is correct?

A person has entered N3 sleep when delta waves account for _____ percent or more of brain wave activity.

A hypnic jerk is likely to occur during

The heart rate slows, breathing becomes more shallow and irregular, and an EEG would show the first signs of sleep spindles in _____ sleep.

Nightmares are more common in children than in adults because

Insomnia can be helped by

Which statement about sleep apnea is true?

Belen often experiences "sleep seizures" during the day. He probably suffers from