REM Rebound
When you are sleep deprived you lose out on two types of sleep, REM and NREM (non-REM). Typically when you have a chance to fall asleep after sleep deprivation you have a tendency to get more REM sleep than you would normally get. This is your body's way of trying to catch up on its REM sleep.
People think they can destress and regulate their emotions by using only their minds.
The Vagus Nerve Miracle