“Learn a new language while you sleep!” may sound like the start of a bad 3 a.m. infomercial, but new research has found some evidence for sleep learning. Of course, listening to French on tape while you sleep is unlikely to instantly give you the ability to order a vanilla latte and an omelet in a foreign tongue the next morning. But it may enhance your ability to learn new vocabulary, according to a study published in Current Biology.

Researchers have long known that sleeping plays an i