Have you ever thought about why people sleep or what purpose sleep serves? This is something that many have wondered for years. Studying what happens when the average person sleeps, how long that person sleeps, and how he or she feels after sleep has taught us a great deal about sleep. Case studies of individuals who have abnormal sleep patterns or sleep needs have also been considered. Some people called nonsomniacs need very little sleep to feel restored. In addition to studying the amount of sleep each person needs, scientists have considered the possible reasons we have different stages of sleep. Scientists have pondered many other things, such as why the amount of time that people spend in different stages of sleep changes over a lifetime.

Answer the following questions:

• Recent studies indicate that the brain takes mini naps when a person is sleep deprived. What role does sleep play in restoring one’s mind? Consider the cognitive changes that a person experiences when sleep deprived. What is it about nonsomniacs that seems to contradict what most believe about the role of sleep?
• What is REM sleep, and what role does it play in memory consolidation? Is the hippocampus, a structure known to play a role in the consolidation of memories, active during REM sleep? Might REM-related dreams be related to one’s actual experiences?
• Why does the amount of time that infants spend sleeping differ from adults? Does REM sleep play a role in the neural development of a young brain? Compare the amount of time people spend in sleep stages over a lifetime. How does slow-wave sleep change over the life span?