Sleep: Sleep paralysis is caused by an abnormal overlap of the REM (rapid eye movement) and waking stages of sleep. Learn more about the stages of sleep Sleep disorders: Here are some other freaky sleep disorders In this short talk, Arianna Huffington shares a small idea that can awaken much bigger ones: the power of a good night's sleep . Instead of bragging about our sleep deficits, she urges us to shut our eyes and see the big picture: We can sleep our way to increased productivity and happiness -- and smarter decision-making.In today's world, balancing school, work, kids and more, most of us can only hope for the recommended eight hours of sleep . Examining the science behind our body's internal clock, Jessa Gamble reveals the surprising and substantial program of rest we should be observing.Here's a cool Reddit post about sleep paralysis.Russell Foster is a circadian neuroscientist: He studies the sleep cycles of the brain. And he asks: What do we know about sleep? Not a lot, it turns out, for something we do with one-third of our lives. In this talk, Foster shares three popular theories about why we sleep, busts some myths about how much sleep we need at different ages -- and hints at some bold new uses of sleep as a predictor of mental health.