Friday, October 8, 2010
Is there one stage of sleep when you can't be awakened?
Sleep consists of three stages plus a stage of rapid eye movement know as REM. When a person enters stage 3, extremely slow brain waves called delta waves are interspersed with smaller, faster waves which progress into delta waves almost exclusively. Stages 3 is referred to as deep sleep or delta sleep, and it is very difficult to wake someone from it.
In deep sleep, there is no eye movement or muscle activity. This is when some children experience bedwetting, sleepwalking or night terrors. Adults spend about 20%of their sleep time in REM and about 15% of their time in Stage 3.