Consider the following data comparing perceived and PSG-derived sleep variables with healthy subjects (no insomnia). Baker and colleagues studied 20 healthy men and women (19-35 yrs. old, free of medications and free of sleep complaints) who had PSG sleep assessed on 3 consecutive nights (Baker et al., 1999). In the morning, subjects were asked to subjectively estimate how long it took to fall asleep (sleep onset latency) and number of awakenings they had after falling asleep. Review the data shown below in preparation for the questions that follow. (Differences are statistically significant for all but sleep onset latency for night 1 in Figure 2.4.2, where p< 0 .001 for 2.4.1 and p< 0.05 for 2.4.2.)

Figure 2.4.1: PSG Sleep Variables vs. Self-reported Sleep Variables Adapted from Baker FC, Maloney S, Driver HS. A comparison of subjective estimates of sleep with objective polysomnographic data in healthy men and women. Journal of Psychosomatic Research. 1999; 47: 335-341.

Figure 2.4.2: PSG Sleep Variables vs. Self-reported Sleep Variables Adapted from Baker FC, Maloney S, Driver HS. A comparison of subjective estimates of sleep with objective polysomnographic data in healthy men and women. Journal of Psychosomatic Research. 1999; 47: 335-341.

Question 2.4.1

These data suggest that overestimation of how long it takes to fall asleep is specific to people reporting insomnia.
	True
	False

Question 2.4.2

People without insomnia tend to underestimate how many times they wake up.
	True
	False

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