For an average adult, what sleep stage is predominately found in the first third of the night?

For an average adult, what sleep stage is predominately found in the first third of the night?

• A. N1
• B. REM
• C. N3
• D. N2

Answer: (C)

The main idea is how sleep stages are distributed across the night. When you first fall asleep, the body prioritizes deep, restorative sleep. This deepest non-REM stage, called slow-wave sleep or N3, is most abundant in the first third of the night. As the night progresses, sleep shifts away from deep sleep toward lighter sleep stages and more REM periods, so REM becomes longer and deeper sleep in the early part declines. N1 is brief and serves as the transition into sleep, and N2 occurs throughout the night but does not dominate the early portion. So the stage most found in the first third of the night is slow-wave sleep (N3).

The main idea is how sleep stages are distributed across the night. When you first fall asleep, the body prioritizes deep, restorative sleep. This deepest non-REM stage, called slow-wave sleep or N3, is most abundant in the first third of the night. As the night progresses, sleep shifts away from deep sleep toward lighter sleep stages and more REM periods, so REM becomes longer and deeper sleep in the early part declines. N1 is brief and serves as the transition into sleep, and N2 occurs throughout the night but does not dominate the early portion. So the stage most found in the first third of the night is slow-wave sleep (N3).