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.
Dr Alan Jones PhD, FRSA