During REM sleep, the eyes contract and the brain is active. Brain activity measured during REM sleep is similar to brain activity during waking hours. Dreams usually occur during REM sleep. Normally, your muscles become flabby to prevent you from realizing your dreams. Typically, you 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?
Sleep patterns and types 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 drops sharply in adolescence. Slow wave sleep continues to decline throughout adulthood and older people may not sleep at all.
NHLBI Sleep Research
Sleep is one of the NHLBI’s four main areas of research. Learn more about the ways the NHLBI is advancing the understanding of sleep and sleep disorders. Research on this topic is part of NHLBI’s broader commitment to advancing scientific discoveries for sleep science.
