Intro to sleep science Flashcards
what is sleep?
The different stages have notable and characteristic differences in EEG (electroencephalogy), EOG (electro-oculargraphy) and EMG (electromyography) actvity . The different stages are classified as REM – Rapid Eye Movement and NREM – Non- Rapid Eye Movement sleep. NREM sleep is then subclassified into stages 1,2 and 3 known as N1, N2 and N3.
Sleep cycles through these different stages in roughly 90 minute cycles.
You might also note that the cycles are not even throughout the night. Sleep is usually entered through stage N1 and rapidly deepens into stage N3 with only a brief period of REM. As the night progresses there is less deep N3 and more REM sleep. The majority of sleep in between periods of REM and N3 is N2 which makes up around 50-60% of normal sleep.
