Which type of sleep is characterized by rapid eye movement?

Rapid eye movement (REM) sleep is indeed characterized by quick, jerky movements of the eyes, which is where it gets its name. This type of sleep is marked by vivid dreaming, heightened brain activity, and muscle atonia, meaning the body is effectively paralyzed during this phase. REM sleep plays a crucial role in emotional regulation and memory consolidation.

In contrast, Non-REM sleep, which includes stages 1, 2, and 3, is characterized by slower brain waves and a more restful state without the rapid eye movements seen in REM. Stage 1 sleep is the transition from wakefulness to sleep and is a light sleep stage; Stage 2 involves deeper sleep but still lacks the eye movement characteristic of REM. Therefore, the unique feature of REM sleep—namely the rapid eye movements—is what sets it apart from other sleep stages.