non-REM
Slow-wave sleep phase
Non-REM refers to the stages of sleep that don't involve rapid eye movement.
Most of a night's sleep is non-REM, cycling through progressively deeper stages before REM sleep occurs.
Non-REM sleep is associated with physical restoration rather than dreaming: She spent more time in non-REM sleep after the marathon.
Unconsciousness hard to rouse
- delta wavesLow-frequency brain oscillations
- restorativePromoting return to health
- brain wavesElectrical patterns from neurons
- sleep spindlesEEG bursts during light rest
muscle tone · heart rate · blood pressure · body temperature · growth hormone · tissue repair · immune function · parasympathetic
Repeating phases of rest
- circadianDaily biological cycle
- adenosinePurine nucleoside in cells
- homeostaticMaintaining internal stability
- sleep pressureBiological demand for rest
sleep debt · chronobiology · neuroimaging · thalamus · cortex · brainstem · neurotransmitter · GABA
Diagnostic overnight monitoring session
- EEGNeural activity recording
- arousalStirring to heightened state
- sleep disorderCondition disrupting normal rest
- insomniaPersistent inability to rest
hypersomnia · parasomnia · sleep apnea · narcolepsy · night terrors · sleepwalking · bruxism · scoring
deep sleep
Unconsciousness hard to rouse
- delta wavesLow-frequency brain oscillations
- restorativePromoting return to health
- brain wavesElectrical patterns from neurons
sleep spindles · muscle tone · heart rate · blood pressure · body temperature · growth hormone · tissue repair · immune function · parasympathetic · metabolic
sleep cycle
Repeating phases of rest
- circadianDaily biological cycle
- adenosinePurine nucleoside in cells
- homeostaticMaintaining internal stability
sleep pressure · sleep debt · chronobiology · neuroimaging · thalamus · cortex · brainstem · neurotransmitter · GABA · sleep deprivation
sleep study
Diagnostic overnight monitoring session
- EEGNeural activity recording
- arousalStirring to heightened state
- sleep disorderCondition disrupting normal rest
insomnia · hypersomnia · parasomnia · sleep apnea · narcolepsy · night terrors · sleepwalking · bruxism · scoring · epoch