Certified Polysomnographic Technician (CPSGT) Practice Exam

REM (Rapid Eye Movement) sleep is characterized by specific physiological changes that distinguish it from NREM (Non-Rapid Eye Movement) sleep. The defining features of REM sleep include the presence of rapid movements of the eyes, increased brain activity, and vivid dreaming. During this phase, the brain exhibits activity levels similar to that of wakefulness, yet the body experiences atonia, a temporary paralysis of most voluntary muscles, which prevents individuals from acting out their dreams.

The phenomenon of dreaming primarily occurs in REM sleep, making it easier to recall dreams upon waking from this stage. This contrasts sharply with NREM sleep, where brain activity is lower, dreams are less common and less vivid, and physical restoration processes are more prominent.

Identifying REM sleep features, such as rapid eye movements and the propensity for dreaming, clarifies the uniqueness of this sleep stage compared to NREM sleep, which is divided into lighter and deeper sleep stages where physiological activity decreases significantly. This fundamental distinction in characteristics emphasizes the importance of REM sleep in overall sleep architecture and cognitive function.