Consciousness, Sleep, and Circadian Rhythms (6B) Practice Test

A laboratory study examines how partial sleep deprivation affects attention. Forty healthy adults complete a 10-minute sustained attention task at 8:00 AM after either a normal night of sleep (8 hours in bed) or restricted sleep (4 hours in bed) for two consecutive nights. Participants are randomly assigned and tested in a quiet room; caffeine is prohibited. Results are summarized below.

Which of the following best explains the changes observed in the study?

A clinic evaluates adults who report difficulty initiating sleep at least 4 nights per week for 3 months. Many describe lying in bed for long periods worrying about the next day. Actigraphy suggests their total sleep time averages 6.5 hours, but sleep onset is delayed and sleep is fragmented. Several report impaired concentration at work and increased irritability. The clinician recommends limiting time in bed to strengthen the bed-sleep association and scheduling a consistent wake time.

Which outcome is most likely given the scenario described?