Stage 1 of NREM Sleep

Stage 1 is the "drift off" period, it is when you are just starting to fall asleep. Stage 1 usually lasts about 10 minutes before changing into stage 2 of NREM sleep.
You can tell some one is in Stage 1 of NREM sleep when they have the following characteristics.
  • Breathing has slowed down
  • Decrease of brain temperature
  • Blood pressure decreases
  • There is little to no body movement
  • Heartbeat becomes regular
  • There is less blood flow to the brain
The brain waves during stage 1 slow down, become smaller, and can be somewhat irregular.
People who are in stage 1 and are waken up will often say they were not actually asleep.

Shai Harvey

1. Non-REM Sleep (2007). Retrieved January 4, 2009, from