what is that thing when you’re asleep but you know you’re awake?

Question: what is that thing when you're asleep but you know you're awake?
- Keywords:
  brain,
  human,
  sleep
Asked by ILOVESCIENCE_Tavishi to Anna, Hayley, Iain, Rebecca on 16 Jun 2015.
- anon answered on 16 Jun 2015:
  
  This is a very fascinating phenomenon which hasn’t been looked into too well yet. Sometimes you may think that you’re awake (even though you are asleep) because you might be in an interphase between wakefulness and sleep (for example, just after having fallen asleep or before waking up).

Question: what is that thing when you're asleep but you know you're awake?