AP PSYCHOLOGY

Detailed explanation-1: -Stage 3 sleep is also known as N3 or deep sleep, and it is harder to wake someone up if they are in this phase. Muscle tone, pulse, and breathing rate decrease in N3 sleep as the body relaxes even further. The brain activity during this period has an identifiable pattern of what are known as delta waves.

Detailed explanation-2: -View Source, stage 3 slow-wave sleep represents the deepest sleep of the sleep cycle, when brain waves are at their slowest in frequency and highest in amplitude. REM: As the name suggests, your eyes move quickly beneath your eyelids during REM sleep. Your brain activity is similar to that of a person who is awake.

Detailed explanation-3: -Stage N3 is deep sleep and lasts about 20 to 40 minutes. During this stage, delta brain activity increases and you may have some body movements. It is very hard to wake up someone in stage N3.

Detailed explanation-4: -In the deepest level of sleep, stage IV sleep, the predominant EEG activity consists of low frequency (1–4 Hz), high-amplitude fluctuations called delta waves, the characteristic slow waves for which this phase of sleep is named. The entire sequence from drowsiness to deep stage IV sleep usually takes about an hour.

Detailed explanation-5: -Sleep stages 3 and 4 are collectively referred to as slow-wave sleep (SWS), most of which occurs during the first third of the night.