A Brief Overview of the Physiology of Sleep. General Awake-state Brain Waves: Active and alert: beta brain waves Tired/meditative state: alpha waves Sleep Cycle Stages: non-REM stage 1: drowsiness theta waves non-REM stage 2: light sleep kappa waves with spindles procedural memory consolidation decrease in neurotransmitters that allow for movement non-REM stage 3: deep sleep delta waves semantic memory consolidation muscle paralysis Disorders: Parasomnia somnambulism (sleep walking) sleep talking night terrors Rapid eye movement stage (REM): “vivid dreaming” (however, studies show dreaming can occur at any stage) beta waves (similar to awake state) REM is due to the eyes tracking mental images Disorders: REM behavior disorders (I.E., acting out one’s dream); associated with Parkinson’s Disease Narcolepsy: immediate transition from awake state to REM; most likely due to unusual levels of orexin (hypothalamic neurotransmitter responsible for satiety and wakefulness) Four to five uninterrupted sleep cycles are required for “effective sleep.”
