During REM sleep, your eyes move and your brain is active. Brain activity measured during REM sleep corresponds to your brain’s activity during waking hours. Dreams usually happen during REM sleep. Your muscles usually go limp to prevent you from living out your dreams. You usually have more REM sleep later in the night, but you don’t have as much REM sleep in colder temperatures. This is because during REM sleep your body does not regulate its temperature properly.
How do our sleep patterns change as we age?
The patterns and types of sleep change as people mature. For example, newborns spend more time in REM sleep. The amount of slow-wave sleep peaks in early childhood and then declines sharply in the teenage years. Slow-wave sleep continues to decline through adulthood, and older people may not have any slow-wave sleep at all.
NHLBI research on sleep
Sleep is one of the four primary areas of NHLBI research. Learn more about how NHLBI advances the understanding of sleep and sleep disorders. Research on this topic is part of NHLBI’s broader commitment to advancing scientific discovery for sleep science.
