How does REM sleep typically differ from NREM sleep?

REM sleep is characterized by increased brain activity, vivid dreaming, and is often referred to as paradoxical sleep because the brain's activity level can resemble that of wakefulness. During this stage, the body experiences atonia, meaning there is a temporary paralysis of most voluntary muscles, which prevents individuals from acting out their dreams. This stage is crucial for cognitive functions, emotional regulation, and memory consolidation.

In contrast, NREM (Non-Rapid Eye Movement) sleep encompasses stages that are more restorative for the body. It is primarily associated with physical recovery, and while dreaming can occur during NREM, it is typically less vivid and less frequent than in REM sleep. The restorative functions come from deep sleep stages, where the body repairs tissues, builds bone and muscle, and strengthens the immune system.

Understanding these differences highlights the unique roles each sleep stage plays in overall health and well-being, underscoring why REM is essential for mental processes, while NREM is vital for physical recovery.