Abstract Study Objectives To investigate how sleep architecture and neurobehavioural functions change during a polyphasic short sleep schedule and to compare these responses to those of a monophasic short sleep schedule with the same total sleep opportunity, as well as to those of a well-rested control group. Methods Forty healthy young adults (18 males, age: 18-35) were assigned to either the monophasic short sleep group, which had a single 2-h sleep opportunity, or the polyphasic short sleep group, which followed the “Uberman” sleep schedule and had six 20-min sleep opportunities distributed evenly across 24-h (one every 4 h). Polysomnography was conducted during every sleep opportunity. Neurobehavioural functions were assessed at baseline (before the sleep opportunity manipulation started) and six times thereafter (once every 4 h). Results Both short sleep groups experienced greater subjective sleepiness, poorer vigilance and lower positive mood as compared to a well-rested control group. Relative to the monophasic short sleep group, the polyphasic short sleep group showed greater vigilance impairment, particularly in the morning. This was accompanied by greater reductions in total sleep time, longer total sleep onset latency and wake after sleep onset, as well as greater proportions of N1 and N2 but lower proportion of N3 sleep in the polyphasic short sleep group relative to the monophasic short sleep group. Conclusions In young adults, the “Uberman” polyphasic sleep schedule substantially reduces total sleep duration and sleep efficiency, even when compared to a monophasic sleep schedule with the same overall sleep opportunity, and may be associated with poorer neurobehavioural performance.
Koa et al. (Tue,) studied this question.