polyphasic sleep

Polyphasic sleep refers to a sleep pattern that consists of two or more sleep phases within a 24-hour period. This contrasts with monophasic sleep, which is a single, continuous sleep period.1

While typical adult sleep patterns involve one long nocturnal sleep, infants naturally exhibit polyphasic sleep, with multiple sleep periods throughout the day. As individuals mature, sleep tends to consolidate into a monophasic pattern. However, some elderly individuals may experience a partial return to polyphasic sleep, with more frequent daytime napping.2

The scientific understanding of sleep has evolved from viewing it as a passive, unitary state to recognizing diverse elements and potential functional roles. This includes the discovery of REM (rapid eye movement) sleep, which is characterized by brain activity similar to wakefulness, and NREM (non-rapid eye movement) sleep, which is more deactivated. Both REM and NREM sleep have distinct stages and cycles that occur throughout the night.3