刘爽

“Sleep is your life-support system and Mother Nature's best effort”， says sleep scientist Matt Walker. In this speech， Walker shares the wonderfully good things that happen when you get sleep —— and the alarmingly bad things that happen when you don't， for both your brain and body. Read this passage and learn more about sleep's effect on your learning， memory， immune system —— as well as some helpful tips for getting some good sleep.

“睡眠是你的生命保障系统，也是大自然的伟大成果”，睡眠专家迈特·沃克如是说。在这篇演讲中，沃克分享了睡眠对大脑和身体的影响。当你睡觉时，会有极好的事发生;而当你不睡觉时，令人担忧的坏事也会发生。读一下这篇文章，了解更多关于睡觉对学习、记忆力、免疫系统的影响，还可以获得一些关于良好睡眠的建议。

I would like to start with the brain and the functions of learning and memory， because what we've discovered over the past 10 years is that you need sleep after learning to save those new memories so that you don't forget. But recently， we discovered that you also need sleep before learning to prepare your brain， almost like a dry sponge ready to soak up new information. And without sleep， you can't absorb new memories.

我想从大脑，以及学习和记忆的功能开始讲起，因为我们在过去十年中发现，学习之后需要睡觉，这样你才不会遗忘。但是最近，我们发现在学习之前也需要睡眠，这样才能准备好自己的头脑，就像是一块干海绵准备好吸收新的知识。没有睡眠的话，你无法吸收新的记忆。

In a study， we took a group of individuals and we assigned them to two experimental groups： a sleep group and a sleep deprivation group. Now the former group， they're going to get a full eight hours of sleep; but the latter， we're going to keep them awake in the laboratory. There's no naps or caffeine， so it's miserable for everyone involved. And then the next day， we're going to place those participants inside an MRI scanner and we're going to have them try and learn a whole list of new facts as we're taking photos of brain activity. And then we're going to test them to see how effective that learning has been. When you put those two groups together， what you find is a quite significant， 40-percent decrease in the ability of the brain to make new memories without sleep.

在這个研究中，我们招募了一组人员，然后将其分到两个实验组：充足睡眠组和剥夺睡眠组。前一个小组的被试者可以睡够八个小时，而后一个小组的被试者会在实验室中一直保持清醒。他们不能小憩，也没有咖啡，所以每个人都很痛苦。第二天，我们把这些被试者放进核磁共振扫描仪，让他们试着学习一整列新知识，同时，会将他们的大脑活跃情况拍摄下来。之后，我们测试他们，来看看他们的学习到底有没有效果。当你把两组照片放在一起比较，你可以发现区别很明显，没有充足睡眠的大脑，储存新记忆的能力会下降40%。

So that's the bad that can happen if I were to take sleep away from you， but let me just come back to that sleep group. Do you remember those individuals that got a full eight hours of sleep？ Well， we can ask a very different question： What is it about the physiological quality of your sleep when you do get it that restores and enhances your memory and learning ability each and every day？ And by testing and studying， what we've discovered is that there are big， powerful brainwaves that happen during the very deepest stages of sleep. And it's the combined quality of these deep-sleep brainwaves that acts like a file-transfer mechanism at night， shifting memories from a short-term vulnerable storage to a more permanent long-term one within the brain， and therefore protecting them， making them safe. And it is important that we understand what during sleep actually transacts these memory benefits， because there are real medical and societal effects.

所以，假如我剥夺你的睡眠，一些糟糕的事情就会发生。但容我稍微讲一下睡眠组。你们还记得那些睡够了八个小时的人吗？……