9. Rapid Eye Movement
REM is where dreaming occurs. During REM, the brain is more active, generating faster and smaller brain waves.
REM or rapid eye movement sleep is the time when we dream, and to prevent us from thrashing about too much or maybe even falling out of bed, we are temporarily paralyzed so that we are not able to physically act our dreams. Some people experience a kind of malfunction upon waking and find that they are still paralyzed and completely unable to move. This is known as Sleep Paralysis but fortunately, is very rare for most people.