sleep spindles
Stage 2
The rhythmic bursts of brain activity that occur during Stage 2 sleep are called sleep spindles. These are short bursts of brain waves that help in the consolidation of memories and are characteristic of this stage of sleep.
Sleep spindles typically appear during stage 2 of non-REM sleep. They are brief bursts of brain activity that help in the consolidation of memories and are associated with the transition from light to deeper sleep.
stage 4
They occur during REM sleep, usually in the second half of the night
They occur during REM sleep, usually in the second half of the night
It happens in the 4th stage
Stage 2 of the sleep cycle usually lasts around 10 to 25 minutes and tends to make up around 45-55% of total sleep time. It is characterized by a decrease in body temperature and heart rate, as well as the presence of sleep spindles and K-complexes on EEG readings.
There are 4 stages of sleep: Stage 1, Stage 2, Slow wave sleep, and REM. The stages occur in that order. Stage 1 occurs as you are falling asleep, and REM occurs last and contains the craziest dreams. REM is the most difficult to awaken from, so it is likely the stage that you have heard referred to as 'deep sleep'.
Bedwetting, or nocturnal enuresis, is most likely to occur during Stage 3 or Stage 4 of non-REM sleep, which is deep sleep. During these stages, the brain may not respond to signals from the bladder indicating the need to urinate, leading to involuntary bedwetting.
There are four stages of sleep: 1) Stage 1 is characterized by theta waves, 2) Stage 2 by sleep spindles and K-complexes, 3) Stage 3 by delta waves, and 4) Stage 4 by predominantly delta waves. As we progress through the stages, brain activity slows down, with deeper stages associated with slower wave patterns.