The one-third of our lives that we spend sleeping, far from being “unproductive,” plays a direct role in how full, energetic and successful the other two are thirds of our lives. our lives can be” (Why we do it). Sleep: A natural and periodically recurring physiological state of rest for the mind and body, characterized by relative physical and nervous inactivity, complete or partial loss of consciousness and reduced reactivity to external stimuli. (Sleep 1062) “Sleep seems like a perfect waste of time,” teases New York Times writer Maria Konnikova. “Why would our bodies evolve to spend almost a third of our lives completely outside of it, when we could be doing something useful or exciting instead” (Konnikova)? Most people view sleep as simply “going to bed,” then “waking up,” and as if there is no in-between. What about when you sleep? being aware of what happens during sleep, understanding unhealthy sleep, knowing what can go wrong and how to sleep in the healthiest way, is all very important. While some may view sleep as a waste of time, life is nothing without sleep. Claudio Stampi, a doctor with a master's degree in neurology from the University of Bologna in Italy, writes in his book "Why We Nap," that "phasic [phasic sleep behavior] is divided into two broad categories: polyphasic and monophasic” (2). The subcategories of polyphasic sleep are pure polyphasic, quasi-polyphasic and semi-polyphasic sleep, the episodes of sleep and activity are uniformly distributed, unlike quasi-polyphasic sleep which is not uniformly distributed. over twenty-four hours. In semi-polyphasic models, sleep consists of one large increment of time, plus numerous other small increments with...... middle of paper......leep Disorders Third Edition. " Written by the publisher. For information Contact: Facts On File An Colophon of Infobase Publishing, 2010. Web. 4 February 2014. Stampi, Claudio. Why we nap: Evolution, chronobiology, and functions of polyphasic, ultrashort sleep Boston: Birkhäuser, 1992. 2. “Sleep” print. Webster's New College Dictionary 1062. Print. “Definitions of Sleep Terms.” Definitions of sleep terms. Np, nd Web. 04 February 2014."Why do we sleep, anyway?" Healthy sleep. Division of Sleep Medicine at Harvard Medical School, December 18, 2007. Web. January 22, 2014."What happens when you sleep?" What happens when you sleep. National Sleep Foundation, 2013. Web. January 26, 2014. US Department of Health and Human Services. In short: your guide to healthy sleep. Np: U.S. Department of Health and Human Services, 2011. Print.