AP PSYCHOLOGY

Detailed explanation-1: -Rapid eye movement (REM) sleep is called paradoxical sleep because it involves seemingly contradictory states of an active mind and a sleeping body.

Detailed explanation-2: -REM sleep is thought to play an important role in memory and learning. During normal sleep, a person goes through four to five sleep cycles that last about 90 minutes each and include both REM sleep and non-REM sleep (light to deep sleep). Also called rapid eye movement sleep.

Detailed explanation-3: -What Defines Paradoxical Sleep? The paradox is that even though the brain is quite active during REM sleep, consuming large amounts of energy, the body remains completely inactive.

Detailed explanation-4: -REM sleep was first discovered in the 1950s, when scientists studying sleeping infants noticed that there were distinct periods when their eyes moved rapidly from side to side. These rapid eye movements, or REMs, earned REM sleep its name.

Detailed explanation-5: -REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due to increased brain activity, but voluntary muscles become immobilized.