Which term describes REM sleep, during which the brain is highly active while the body is largely immobile?

Which term describes REM sleep, during which the brain is highly active while the body is largely immobile?

• A. Paradoxical sleep
• B. NREM sleep
• C. REM rebound
• D. Jet lag

Answer: (A)

Paradoxical sleep is REM sleep, the stage where the brain is highly active—think wakeful-like activity on EEG and vivid dreaming—yet the body is largely immobile due to muscle atonia that prevents acting out dreams. This combination, a brain firing as if awake while the body stays still, is what gives REM its name. Other options describe different ideas: non-REM sleep involves slower brain activity and more physical stillness but lacks the dream-rich, highly active brain pattern of REM; REM rebound refers to an increased REM period after sleep deprivation, not the defining feature of REM itself; jet lag is about misalignment of the internal clock with the external environment, not a sleep stage.

Paradoxical sleep is REM sleep, the stage where the brain is highly active—think wakeful-like activity on EEG and vivid dreaming—yet the body is largely immobile due to muscle atonia that prevents acting out dreams. This combination, a brain firing as if awake while the body stays still, is what gives REM its name.

Other options describe different ideas: non-REM sleep involves slower brain activity and more physical stillness but lacks the dream-rich, highly active brain pattern of REM; REM rebound refers to an increased REM period after sleep deprivation, not the defining feature of REM itself; jet lag is about misalignment of the internal clock with the external environment, not a sleep stage.