Video: Why do we sleep? – Russell Foster

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.

Relax, watch, enjoy and learn.