Narrator:        This is Science Today. Cramming for tests by pulling an ‘all-nighter' is a rite of passage for many college students. But getting a good night's sleep may get better results. Matthew Walker, director of the University of California, Berkeley's Sleep and Neuroimaging Laboratory, says that's because one of the functions that sleep supports is the regulation of our abilities to learn and memorize.

Walker:          What's interesting is after that memory has first been born, it's actually very fragile and vulnerable and it's susceptible to being lost or overwritten, for example, by competing information coming in. So for that new memory to persist long term, it has to pass through a second step that we call memory consolidation.

Narrator:        Using brain imaging technology, Walker and his colleagues found that sleep after learning seems to be critical for memory consolidation.

Walker:          But what's remarkable is that sleep doesn't simply seem to stabilize those memories - sleep seems to enhance them. So that you come back the next day and you're even better able to recall that information than you were the day before.