difference between light sleep and deep sleep
Stage 2 â A deeper sleep where your body temperature cools a little and you become disengaged from your surroundings. Stages 3 and 4 â These are 'deep sleep'. It is very hard to wake up from deep sleep because this is when there is the lowest amount of activity in your body.
NREM Stage 1. Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves.