Question

For young adults, does sleep getting lighter or deeper as the night progresses? Explain your answer.

Answer 1

In a young adult, normal sleep architecture usually consists of four or five alternating non-REM and REM periods. Normally, young people spend about 20% of their sleep time in stretches of deep sleep lasting up to half an hour and most deep sleep occurs in the first half of the night. As the night progresses, periods of REM sleep get longer and alternate with stage N2 sleep, which is considered as light sleep. Deep sleep is nearly absent in most people over age 65. I