REM

• REM

  A period of rapid eye movement sleep during which the eyeballs rapidly move beneath closed eyelids
• Brainwave pattern associated with REM sleep

  • Irregular
  • Low amplitude
  • Relatively high-frequency beta waves
  • Similar to those produced in alert wakefulness
• The body’s internal functioning is more active during REM sleep compared to NREM sleep
• Heart rate during REM sleep

  Faster and more irregular
• Blood pressure during REM sleep

  Rises
• Breathing during REM sleep

  Quicker and more irregular
• The sleeper is totally relaxed during REM sleep
• Twitching movements during REM sleep

  Occasional in the face, fingers, and toes
• Most of the skeletal muscles are limp and do not show signs of movement during REM sleep
• Paradoxical sleep

  Internally the brain and body are active but the external body appears calm and inactive
• The purpose of body paralysis during REM sleep is unknown
• Psychologists suggest that body paralysis may have evolved to prevent us from acting out our dreams
• Research indicates that most dreaming occurs during REM sleep
• If a participant is woken during REM sleep, about 80% of the time they report having been dreaming
• Some people say that they do not dream, but research suggests we dream several times in a night
• We may not remember all of our dreams
• Dreaming in NREM sleep

  Occurs but much less, less vivid and less fragmented than REM dreams
• Rapid eye movement in REM sleep

  Not due to the content of our dreams but due to physiological activity occurring at the same time as random neural activity in the brain
• Researchers are not too sure about the cause of rapid eye movement in REM sleep
• The progression through NREM sleep cycle from stage 1 to stage 4 takes about 45-60 minutes
• NREM sleep cycle progression

  1. Stage 1

  2. Stage 2

  3. Stage 3

  4. Stage 4
• After passing through one complete NREM cycle, we do not awaken even though our brain and body begin to respond as if we are on the point of waking up
• These are all signs that we are about to enter REM sleep
• Throughout the night we continuously pass through NREM and REM sleep cycles
• REM periods

  Lengthening and occurring closer together as the night progresses
• An REM period that occurs early on in the night may only last for up to a few minutes
• A later REM period may last up to an hour or so
• This may explain why you are often dreaming when your alarm wakes you up in the morning
• Whether or not REM sleep is considered to be light sleep or deep sleep

  Depends on the criteria used
• REM sleep is clearly more like wakefulness than NREM sleep


  When the brain wave activity is considered
• If muscle tone is considered

  REM sleep can be called deep sleep due to muscle tone being at its lowest point
• Psychologists tend to view REM sleep as sharing properties of both light and deep sleep