sleep deprivation can have devastating effects if it is total. Psychologist Allan Rechtschaffen of the University of Chicago produced profound, lethal, metabolic changes 25 in rats totally deprived of sleep from less than a week to more than a month. But true sleep deprivation is very hard to arrange, since animals and humans sneak in"micro-sleeps." Long-suffering chronic insomniacs may say they"never catch a wink of sleep." but they're rarely totally sleep deprived, and usually get at least a few hours a night.