Translations:Segmented/3/en

Segmented sleep, sometimes referred to as bifurcated or divided sleep, is one of the original polyphasic sleep patterns. It is the basis of the Dual core schedule line. In its non-reducing form, it is believed to have been practiced by some human societies since time immemorial until the advent of electric lighting . In short photoperiods (fewer daylight hours), it has been shown that human sleep is naturally segmented.