Americans are not famous for self-deprivation, but experts say we consistently fail to get a good night's sleep. The recommended daily requirements should sound familiar: eight hours of sleep a night for adults and at least an hour more for adolescents. Yet 71 % of American adults and 85% of teens do not get the suggested amount. “Sleep is sort of like food,? says Robert Stickgold, a cognitive (认知的）neuroscientist at Harvard Medical School But, he adds，there's one important difference: “You can be quite starved and still alive, and I think we appreciate how horrible