Which stage of sleep is characterized by light sleep and a brief transition into deeper stages?

The stage of sleep characterized by light sleep and a brief transition into deeper stages is N1, also known as the initial stage of NREM sleep. During this period, a person begins to drift into sleep, experiencing a decrease in heart rate and muscle activity. N1 typically lasts for only a few minutes and serves as the bridge between wakefulness and deeper sleep stages.

In this stage, individuals may experience various phenomena, such as hypnic jerks or sensations of falling, which can lead to temporary wakefulness. As the body continues to relax, it transitions into deeper sleep stages, particularly N2 and N3.

The distinction of N1 as light sleep emphasizes its role as the initial phase before entering the more restorative and deeper stages (N2 and N3), whereas REM sleep, which is often associated with vivid dreaming, occurs later in the sleep cycle.