After all of the 30-second epochs for the patient described previously were scored for wake or sleep stage, they were entered into the computer to create a nighttime summary. The time spent in each stage (minutes across the night) is totaled in a sequential episodic way across time or as a percent of the total time designated as sleeping after falling asleep. This graph indicates the time spent in each sleep stage and the cycling through stages during the night (Pressman et al., 1997). On the graph you will see a repetitive sequence of going from awake or non-REM sleep stages into REM sleep (dark horizontal bar). Each REM stage end signals the end of a complete sleep cycle. Not all cycles include entering stages 3 & 4 (deep sleep).

Figure 1.8.1: The Normal Sleep Pattern of a Young Adult

Question 1.8.1
How many complete sleep cycles are depicted on this graph?
	3
	4
	5

Question 1.8.2
The approximate range of the sleep cycle duration is:
	1 - 1.5 hours
	1.5 - 2 hours
	2 - 3 hours

Question 1.8.3
After falling asleep, how many times did this person wake up before final awakening?
	1
	5
	6

Question 1.8.4
This graph suggests that for young adults more deep sleep (delta, SWS) occurs in the early part of the night.
	True
	False

Question 1.8.5
This graph suggests that for young adults there is proportionally less REM sleep within a cycle as the nighttime sleep period lengthens.
	True
	False

Question 1.8.6
This graph suggests that over the night, young adults spend roughly 50% of the sleep time in light sleep and 15-20% in deep sleep.
	True
	False

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