(This video is no longer available for streaming.) We spend about one-third of our lives sleeping. Why? Believe it or not, scientists don't know for sure. But evidence is building that sleep may play a crucial role in strengthening memories and facilitating learning, not just in humans but in most animals.
NOVA scienceNOW visits research labs at the University of Pennsylvania and MIT, where scientists are peering into the brains of dozing flies and rats to understand the connection between sleep and memory. At Harvard Medical School, host Neil deGrasse Tyson tests his powers of learning on a virtual ski machine and a speed typing exercise, and then catches some z's. He discovers that it's not practice that makes perfect, but practice plus a good night's sleep.