SSS 2009-11-19（在线收听）

There’s nothing like a good nap. It can refresh your mood—and possibly your memory. Because a new study in the journal Science shows that a quick snooze after a mental workout helps to consolidate learning. And that sounds heard during sleep can trigger associations that sharpen memory even more.

A dozen subjects took a memory test in which they learned the positions of 50 objects on a computer screen. Each picture was paired with its own little sound effect. So, an image of a shattering wine goblet was accompanied by the tinkle of breaking glass. [glass break sound] Little sticks of dynamite? [boom sound] And so on.

Once the subjects had learned to put the pictures where they belong, they were escorted to a dark room, fitted with electrodes, and encouraged to take a little nap. While they slept, scientists played the sound cues for half the images presented during the memory test. And when the subjects woke up and retook the test, they were better at placing the 25 objects that sounded off during the siesta. Even though none of them reported actually hearing anything.

So a sound sleep may help you find your car keys. Especially if they [car keys chirp sound] while you [snore sound].