Narrator: This is Science Today. Cutting your sleep short could impair your ability to learn. Researchers at the University of California, Berkeley, have found that short bursts of brain waves called "sleep spindles," which occur during the second half of the sleep cycle, may be critical to the learning process.
Mander: Spindles are most prominent in state two non-REM sleep, which is often considered this lighter stage of sleep. And most of the time you spend in that sleep is actually spent in the second part of the night so it's your late morning sleep. That becomes particularly important when people start restricting their sleep ...they're going to lose a lot of stage two, which means they're going to lose a lot of spindles, which means they're not going to learn as well.
Narrator: Researcher Bryce Mander says that the invention of the light bulb and the lengthening work day have all had a negative impact on our sleep mentality. National sleep polls show sleep time has been steadily dropping.
Mander: If you look at sleep in America, polls that have been going on since the early '90s, the average amount of reported sleep time has been steadily dropping. Well, that may have a long-term effect at a societal level relating to all sorts of physiological processes from metabolism to learning.
Narrator: For Science Today, I'm Larissa Branin.