Biphasic Sleep Pattern
A biphasic sleep pattern is defined as sleeping in two distinct blocks within a 24-hour period, with a period of wakefulness separating the blocks.
Typical Timing
A common example is a “split” pattern with a main nocturnal sleep episode and a second shorter sleep episode (nap-like) later in the day or early evening.
Distinction From Related Patterns
A biphasic pattern is distinct from polyphasic sleep, which involves multiple sleep episodes within 24 hours, and from monophasic sleep, which involves a single consolidated sleep episode within 24 hours.
Clinical Relevance
Biphasic sleep can occur naturally in some individuals, and it may also be observed in certain clinical or environmental contexts such as circadian disruption or irregular schedules.