John is participating in a sleep study. While examining John's EEG pattern, the researcher notices that the waves are extremely regular, with a frequency of 7 to 11 Hz. Based on this observation, the researcher can conclude that John is:
Sarah is participating in a sleep study. Although she appears to be sleeping, her EEG pattern exhibits fast brain-wave activity, and the recording from the electrooculogram seems to indicate that she is moving her eyes. This suggests that Sarah:
Letizia is participating in a study on sleep. As she sleeps, the researchers are likely to notice that in the first part of her night's sleep, _____ sleep is prominent, whereas in the second part, _____ sleep dominates.