Aramaiti Sabah - Penerbangan Ke Sabah
Stage 1 (NREM1 or N1) is the stage between wakefulness and sleep, sometimes referred to as somnolence or drowsy sleep, in which the muscles are still quite active and the eyes roll around slowly and may open and close from time to time.
Stage 2 (NREM2 or N2) is the first unequivocal stage ofsleep, during which muscle activity decreases still further and conscious awareness of the outside world begins to fade completely. If any sounds are heard, the sleeper is not able to understand their content at this point.
Stage 3 (NREM3 or N3) is also known as deep or delta or slow-wave sleep (SWS), and during this period the sleeper is even less responsive to the outside environment, essentially cut off from the world and unaware of any sounds or other stimuli.