Sleep is the natural state of bodily rest observed in animals. It is common to all mammals and birds, and is also seen in many reptiles, amphibians and fish. In humans, other mammals, and a substantial majority of other animals which have been studied —such as some species of fish, birds, ants, and fruit-flies—, regular sleep is essential for survival.
A widely publicized 2003 study performed at the University of Pennsylvania School of Medicine demonstrated that cognitive performance in humans declines with fewer than eight hours of sleep.However, the purposes of sleep are only partly clear and are the subject of intense research.
No comments:
Post a Comment