🔗 Polyphasic Sleep

🔗 Medicine 🔗 Psychology 🔗 Physiology

Biphasic sleep (or diphasic, bimodal or bifurcated sleep) is the practice of sleeping during two periods over the course of 24 hours, while polyphasic sleep refers to sleeping multiple times – usually more than two. Each of these is in contrast to monophasic sleep, which is one period of sleep within 24 hours. Segmented sleep and divided sleep may refer to polyphasic or biphasic sleep, but may also refer to interrupted sleep, where the sleep has one or several shorter periods of wakefulness. A common form of biphasic or polyphasic sleep includes a nap, which is a short period of sleep, typically taken between the hours of 9 am and 9 pm as an adjunct to the usual nocturnal sleep period. Nowadays, the definition of polyphasic sleep is any sleep schedule with at least two sleeps per day, to distinguish it from monophasic sleep, which only has one sleep per day.

The term polyphasic sleep was first used in the early 20th century by psychologist J. S. Szymanski, who observed daily fluctuations in activity patterns (see Stampi 1992). It does not imply any particular sleep schedule. The circadian rhythm disorder known as irregular sleep-wake syndrome is an example of polyphasic sleep in humans. Polyphasic sleep is common in many animals, and is believed to be the ancestral sleep state for mammals, although simians are monophasic.

The term polyphasic sleep is also used by an online community that experiments with alternative sleeping schedules to achieve more time awake each day. However, researchers such as Piotr Woźniak warn that such forms of sleep deprivation are not healthy. While many claim that polyphasic sleep was widely used by some polymaths and prominent people such as Leonardo da Vinci, Napoleon, and Nikola Tesla, there are few reliable sources supporting that view.