Posts

Showing posts with the label sleep stages

UNDERSTANDING SLEEP

   Most of the progress in understanding sleep mechanics has been made in the last 50 years. What has been learned explodes some long-standing misconceptions. One is the assumption that since many bodily functions slows down during rest; sleep is little more than a state of inactivity.        By studying brain-wave patterns, medical researchers have learned that there are repeated cycles and stages of sleep. Far from being inactive, the human brain runs at high speed during certain periods of sleep. Healthful sleep involves going through these cycles four or more times every night and spending a sufficient amount of time in each cycle.          A normal night’s sleep is most easily divided into 2 types: what is commonly called REM [rapid eye movement, or dream] sleep and non-REM [nondream] sleep. You can tell a person is in REM sleep when the bulge of his eyeballs can be seen rapidly moving under his eyelids.         Non-REM sleep can be further divided into 4 sta