Written by the Fiveable Content Team โข Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 examโขWritten by the Fiveable Content Team โข Last updated September 2025
Definition
Rapid Eye Movement (REM) Sleep is a unique phase of mammalian slumber characterized by random movement of eyes, low muscle tone throughout the body, and vivid dreams.
Related terms
Paradoxical Sleep: Another term for REM due to its paradoxical qualities; despite being deeply asleep our brains are highly active, almost as if we were awake.