<unk>  <unk> , also known as quiescent sleep, is, collectively, sleep stages 1–3, previously known as stages 1–4. Rapid<unk>  movement sleep (REM) is not included. There are distinct electroencephalographic and other characteristics seen in each stage. Unlike<unk> , there is usually little or no<unk>  movement during these stages. Dreaming occurs in both during both sleep states, and muscles are not paralyzed as in<unk> . People who do not go through the sleeping stages properly get stuck in<unk> , and because muscles are not paralyzed a person may be able to sleepwalk. According to studies, the mental activity that takes place during<unk>  is believed to be thought-like, whereas<unk>  includes hallucinatory and bizarre content.<unk>  is characteristic of dreamer-initiated friendliness, compared to<unk>  where it's more aggressive, implying that<unk> is in charge of simulating friendly interactions. The mental activity that occurs in<unk> and<unk>  is a result of two different mind generators, which also explains the difference in mental activity. In addition, there is a parasympathetic dominance during<unk>  The reported differences between the REM and<unk> activity are believed to arise from differences in the memory stages that occur during the two types of sleep.
Non-rapid eye movement sleep
Rapid eye movement sleep
Slow-wave sleep
Biphasic and polyphasic sleep
Sleep onset
Postictal state
Golden hour 
Twilight sleep