21) The hormone melatonin reaches peak levels in the body during the a. morning. b. early evening. c. afternoon. d. night. 22) Melatonin is a a. stimulant. b. hormone. c. depressant. d. sleeping pill. 23) Melatonin is to ___________ as an aspirin is to ____________. a. nausea; nightmare b. insomnia; headache c. nightmare; blood clots d. apnea; blood thinner 24) We spend the greatest amount of time engaged in what altered state of consciousness? a. Sleeping b. Out-of-body experiences c. Dreaming d. Under the influence of drugs 25) Sid is taking part in research on the effects of sleep deprivation; he has been without sleep for 75 hours. Right now researchers have asked him to sit in front of a computer screen and hit a button each time he sees the letter S on the screen. A few days ago, Sid was a whiz at this task; however, he is doing very poorly today. How are sleep researchers likely to explain Sid’s poor performance? a. Due to the sleep deprivation, Sid does not understand the task. b. He has accumulated a “sleep debt†that impedes his learning, attention, and reaction time. c. He is determined to ruin the research because of the suffering he is enduring at the hands of the researchers. d. He is probably dreaming that he is somewhere else and has no interest in responding to the “here and now.†26) According to research on sleep deprivation, a moderate amount of sleep loss a. is still a serious problem. b. is not a problem at all. c. only is a problem for women, not men. d. does not affect people older than age 50. 27) All of the following result from sleep deprivation except a. droopy eyelids. b. irritability. c. hyperalertness. d. cognitive impairment. 28) Which of the following can be an emotional symptom of sleep deprivation? a. Hyperactivity b. Cheerfulness c. Depression d. Nausea 29) Even though sleep research suggests that most college students require approximately ________ hours of sleep nightly, they often get ________ hours. a. 9; 8 b. 9; 6 c. 7; 6 d. 10; 8 30) The human circadian rhythm can be disrupted by a. sleep deprivation. b. working the late shift. c. jet lag. d. all of the above.