【双语 | TED科普】如何快速提高睡眠质量

Your eyes get heavy and gradually close. But wait, it's only lunchtime and you still have so much to do. Would taking a nap help or would it derail your day?

你的眼睛变得沉重并逐渐闭上。但是等等，现在才到午餐时间，你还有很多事情要做。打个盹会有帮助还是会破坏你的一天?

Our sleep, both at night and in naps, is made up of approximately 90 minute sleep cycles with 4 stages each. A nap can last anywhere from 5 minutes to 3 hours, so it can include full sleep cycle or just a few stages. As you fall asleep, you enter stage one, the first 2:5 minutes of sleep. Stage 2 comes next. For about 30 minutes in stage 2, body temperature drops, muscles relax and breathing and heart rate become more regular.

我们的睡眠，无论是长眠还是小睡，都是由大约90分钟的睡眠周期组成的，每个周期分为4个阶段。小睡可以持续5分钟到3个小时，所以它可以包括整个睡眠周期，也可以只有几个阶段。当你入睡时，你进入第一阶段，第一个2到5分钟的睡眠。接下来是第二阶段。在第二阶段大约30分钟，体温下降，肌肉放松，呼吸和心率变得更有规律。

Your neurons start to fire in unison, creating waves of activity that sweep across the globe cortex, punctuated by rapid bursts of neural activity called sleep spindles. As you enter stage 3, or slow wave sleep, the rolling waves increase as your neurons fire in coordination. This phase lasts about 20to 30 minutes and is where your deepest sleep occurs. Then you enter ERMsleep, which lasts about 10to 20 minutes. In a nap in REM, the brain becomes more active, more like your brain activity while awake. The end of REMsignals the completion of a sleep cycle. Okay, but will a nap make you feel better?

你的神经元开始齐刷刷地放电，产生横扫整个大脑皮层的活动波，其间穿插着被称为睡眠纺锤波的神经活动的快速爆发。当你进入第三阶段，即慢波睡眠时，当你的神经元协同工作时，滚动波会增加。这个阶段持续大约20到30分钟，是你进入最深睡眠的时候。然后进入快速睡眠，持续大约10到20分钟。在快速眼动的小睡中，大脑变得更加活跃，更像你清醒时的大脑活动。快速眼动结束标志着一个睡眠周期的结束。好吧，小睡会让你感觉好点吗?

Well, that depends on a few things, especially what stages of sleep the nap includes. Take a 30 minute nap, which consists mainly of stage 2 sleep. Stage 2 sleep is associated with long term potentiation, a process that's thought to strengthen the synapses between neurons, which is essential for learning.

这取决于一些事情，尤其是午睡包括哪些睡眠阶段。小睡30分钟，主要包括第二阶段睡眠。第二阶段睡眠与长期增强有关，这一过程被认为是加强神经元之间的突触，这对学习至关重要。

A 20to 30 minute nap stops short of stage 3 's deep sleep, making it relatively easy to wake up from. A 30to 60 minute nap, meanwhile, has the benefits of stage 2 sleep and also takes you into the deeper sleep of stage 3. During stage 3, multiple brain areas work together to transfer information from short term memory storage to long term storage, stabilizing and strengthening long term memory by coupling sleep spindles with slow waves.

20到30分钟的小睡会阻止第三阶段的深度睡眠，使其相对容易醒来。与此同时，30到60分钟的小睡不仅对第二阶段睡眠有好处，还能让你进入第三阶段的深度睡眠。在第三阶段，大脑多个区域共同工作，将信息从短期记忆存储转移到长期记忆存储，通过将睡眠纺锤波与慢波耦合来稳定和加强长期记忆。

Stage 3 is the most difficult stage to wake up from. So while a 30to 60 minute nap can have cognitive benefits. Those benefits often don't kick in until about 15,15 minutes after waking up. 60to 90 minute naps enter the REMstage.

第三阶段是最难醒来的阶段。因此，虽然30到60分钟的小睡对认知有好处。这些好处通常要到醒来15分钟后才会显现出来。60 - 90分钟的小睡即进入快速眼动阶段。

While in REM, the prefrontal cortex, which is largely responsible for inhibition and cognitive control, becomes much less active. Meanwhile, the amygdala and cingulate cortex, regions associated with emotion and motivation, are highly active. Researchers have posited that the combination of these things leads to bizarre dreams.

在快速眼动期间，主要负责抑制和认知控制的前额叶皮层变得不那么活跃。与此同时，与情绪和动机相关的杏仁核和扣带皮层高度活跃。研究人员推测，这些因素的结合会产生做奇怪的梦。

During REMsleep, the decrease in inhibition and cognitive control might lead to wild associations. And thanks to the amygdala and cingulate cortex activity, those associations can be between emotionally charged topics. Some researchers think this stage might help us make innovative connections between ideas upon waking, because the brain activity during REMis closer to waking, it may be easier to wake up from REMthan stage 3, even though the nap is longer.

在快速眼动睡眠期间，抑制和认知控制的减少可能导致狂野的联想。由于杏仁核和扣带皮层的活动，这些联系可以发生在情绪激动的话题之间。一些研究人员认为，这一阶段可能有助于我们在清醒时在想法之间建立创新的联系，因为快速眼动期间的大脑活动更接近清醒，即使小睡时间更长，也可能比第三阶段更容易从快速眼动中醒来。

The time of day also matters. Our need for deep stage 3 sleep progressively increases throughout the day. So if you nap later, you may rob yourself of the sleep pressure needed to go to sleep at night. This doesn't happen for REMsleep. Longer periods of REMoccur during morning hours, so morning naps are dominated by REM, midday naps have about equal parts of REMand deep sleep, and evening naps contain more deep sleep.

一天中的时间也很重要。我们对深度第三阶段睡眠的需求在一天中逐渐增加。所以，如果你晚睡，你可能会剥夺自己晚上入睡所需的睡眠压力。这种情况不会发生在快速眼动睡眠中。较长时间的快速眼动发生在早上，所以早上小睡以快速眼动为主，中午小睡的快速眼动和深度睡眠的比例大致相等，晚上小睡则包含更多的深度睡眠。

On top of all this, it seems that we're just about evenly split between nappers and non nappers. Nappers consistently show cognitive benefits from napping, but non nappers may not. Researchers think this could be because nappers are able to stay in a lighter sleep and move through sleep stages more easily. Meanwhile, non nappers may experience more deep sleep while napping, making them groggy afterward. So will a nap help? Well, there's only one way to find out.

最重要的是，我们似乎在午睡和不午睡之间平分。午睡者一直表现出午睡对认知的好处，但不午睡的人可能不会。研究人员认为，这可能是因为午睡者能够保持较浅的睡眠状态，更容易进入睡眠阶段。与此同时，不午睡的人在午睡时可能会经历更多的深度睡眠，使他们在午睡后昏昏沉沉。那么小睡一下会对自己有帮助吗?只有一试一试才知道。