We welcome you to our beautiful city! This is truly an exciting time for Worcester. Major investments in transportation improvements such as roadway network reconstruction projects and the provision of commuter rail service at the magnificently renovated Union Station are generating new economic activity.
Since the early 20th century, human sleep has been described as a succession of five recurring stages: four non-REM stages and the REM stage. (A sixth stageârelaxed wakefulness, the phase during which a person falls asleepâis sometimes included).
TYPES AND STAGES OF SLEEP. REM SLEEP. REM sleep occurs in cycles of about 90-120 minutes throughout the night, and it accounts for up to 20-25% of total sleep time in adult humans, although the proportion decreases with age (a newborn baby may spend 80% of total sleep time in the REM stage).