Sleep - AP Psychology

Delta waves. The slowest brain waves, characteristic of deep sleep stages.

Melatonin. Released by the pineal gland in response to darkness.

Stage 3 of NREM sleep. Deep sleep stage when complex motor behaviors can occur.

Rapid Eye Movement sleep; a sleep stage with vivid dreams. Stage characterized by dreaming and temporary muscle paralysis.

Difficulty falling asleep at conventional times. Circadian rhythm disorder causing delayed sleep-wake timing.

Stage 3 of NREM sleep. Deep sleep promotes physical recovery and tissue regeneration.

Conserves energy and protects from predators. Evolutionary theory explaining sleep as survival mechanism.

Anticipatory arousal. Biological clock can trigger awakening before external stimuli.

Temporary inability to move or speak upon waking. REM muscle atonia persists briefly into waking consciousness.

Norepinephrine. Stimulant neurotransmitter that maintains alertness and arousal.

Melatonin. Released by the pineal gland in response to darkness.

Lack of vivid dreaming. NREM stages feature minimal dream activity and slower brain waves.

Delays sleep onset and reduces sleep quality. Stimulant blocks adenosine receptors, preventing sleepiness signals.

An involuntary muscle twitch during sleep onset. Normal muscle spasm occurring during transition to sleep.

Rapid Eye Movement sleep; a sleep stage with vivid dreams. Stage characterized by dreaming and temporary muscle paralysis.

Approximately 90 minutes. Time to progress through all NREM and REM stages once.

Sleep restores body and brain functions. Theory suggesting sleep repairs cellular damage and waste removal.

REM sleep. Most vivid dreams occur during this rapid eye movement stage.

Stage 3 of NREM sleep. Deep sleep dominated by delta waves under 4 Hz.

Suppresses melatonin production. Disrupts natural melatonin release, delaying sleep onset.

Stage 2 of NREM sleep. Brief bursts of brain activity that help maintain sleep.

Disrupts REM sleep. Alcohol fragments sleep and reduces restorative REM phases.

Hypothalamus. Contains the suprachiasmatic nucleus, the body's master clock.

Grogginess and impaired performance after waking. Temporary cognitive impairment immediately following awakening.

Uncomfortable urge to move the legs. Neurological condition causing irresistible urges to move legs.

Hypnogogic state. Drowsy state between wakefulness and sleep onset.

Reinforces learning and memory. Sleep strengthens neural connections formed during learning.

Increased risk of chronic diseases. Persistent sleep loss increases cardiovascular and metabolic disease risk.

Temporary inability to move or speak upon waking. REM muscle atonia persists briefly into waking consciousness.