You've been studying and playing for days, but you still don't feel ready for either.

儘管接連幾日地念書和練琴，你還是覺得兩個都沒有準備好。

So, what can you do?

那麼，你可以怎麼做呢？

Well, you can drink another cup of coffee and spend the next few hours cramming and practicing, but believe it or not,

你大可以再喝一杯咖啡，然後花接下來數小時死背和練琴，但是信不信由你，

you might be better off closing the books, putting away the music, and going to sleep.

對你最好的做法其實是闔上書本、收起樂譜，然後快點去睡覺。

Sleep occupies nearly a third of our lives, but many of us give surprisingly little attention and care to it.

睡眠佔據人生近三分之一的光陰，但令人詫異的是，我們多數人都對睡眠漠不關心。

This neglect is often the result of a major misunderstanding.

這種忽視通常是來自對睡眠的一個重大誤解。

Sleep isn't lost time, or just a way to rest when all our important work is done.

睡眠不是浪費時間，也不是單純完成重要工作後的喘息時間。

Instead, it's a critical function, during which your body balances and regulates its vital systems,

相反的，睡眠是一個重要的功能，讓你的身體在這期間可以平衡並調節重要系統，

effecting respiration and regulating everything from circulation to growth and immune response.

影響著你的呼吸，幫你調節身體，像是血液循環、生長及免疫反應。

That's great, but you can worry about all those things after this test, right?

那很好，但是你可能想等考完這次試後再來討論，對吧？

Well, not so fast.

你可別著急。

It turns out that sleep is also crucial for your brain, with a fifth of your body's circulatory blood being channeled to it as you drift off.

事實證明，睡眠對大腦也非常重要，因為當你漸漸入睡，體內五分之一的循環血液將被輸送到大腦。

And what goes on in your brain while you sleep is an intensely active period of restructuring that's crucial for how our memory works.

你的大腦接著會在你睡眠期間，進入非常活躍的重整期，這對於記憶的形成至關重要。

At first glance, our ability to remember things doesn't seem very impressive at all.

乍看之下，我們能夠記住東西的能力似乎沒什麼了不起的。

19th-century psychologist Hermann Ebbinghaus demonstrated that we normally forget 40% of new material within the first 20 minutes, a phenomenon known as the forgetting curve.

十九世紀心理學家斯赫爾曼．艾賓豪斯指出，我們在接收新訊息的前 20 分鐘內，通常會忘掉 40％ 的內容，這現象被稱作「遺忘曲線」。

But this loss can be prevented through memory consolidation, the process by which information is moved from our fleeting short-term memory to our more durable long-term memory.

不過這種遺失可以透過記憶鞏固加以預防，訊息會在記憶鞏固過程中，會從轉瞬即逝的短期記憶，轉變成持久的長期記憶。

This consolidation occurs with the help of a major part of the brain known as the hippocampus.

幫助記憶鞏固的最大功臣，就是大腦中一大塊被稱為「海馬迴」的部位。

Its role in long-term memory formation was demonstrated in the 1950s by Brenda Milner in her research with a patient known as H.M.

布蘭達．米爾納在50 年代針對一名叫H.M. 病患的研究中，展現出海馬迴在長期記憶成型扮演的角色

After having his hippocampus removed, H.M.'s ability to form new short-term memories was damaged, but he was able to learn physical tasks through repetition.

當 H.M. 的海馬體被移除後，他喪失了形成新短期記憶的能力，但他依舊能夠透過反覆練習學會某些肢體動作。

Due to the removal of his hippocampus, H.M.'s ability to form long-term memories was also damaged.

由於海馬體被移除，H.M. 形成長期記憶的能力也因此受損。

What this case revealed, among other things, was that the hippocampus was specifically involved in the consolidation of long-term declarative memory,

這個案例研究顯示，海馬體確實與鞏固長期陳述性記憶有關，

such as the facts and concepts you need to remember for that test, rather than procedural memory, such as the finger movements you need to master for that recital.

像是你考試時需要記住的事實和概念，而不是一些程序記憶，像是彈鋼琴所需的手指動作。

Milner's findings, along with work by Eric Kandel in the 90's, have given us our current model of how this consolidation process works.

米爾納的發現和埃里克．坎德爾 90 年代的研究，給了我們現代「記憶鞏固」過程的基本模型。

Sensory data is initially transcribed and temporarily recorded in the neurons as short-term memory.

感知數據原先被轉譯，並暫時紀錄在神經元內，形成短期記憶。

From there, it travels to the hippocampus, which strengthens and enhances the neurons in that cortical area.

訊息會再從那裡傳送到海馬迴，強化大腦皮層區神經元的聯結。

Thanks to the phenomenon of neuroplasticity, new synaptic buds are formed, allowing new connections between neurons, and strengthening the neural network where the information will be returned as long-term memory.

因為神經的可塑性，新的神經突觸得以形成，讓神經元間產生新連結並強化網絡，使資訊得以轉換為長期記憶。

So why do we remember some things and not others?

那麼，我們為什麼能夠記得某些事，卻又忘記其它事呢？

Well, there are a few ways to influence the extent and effectiveness of memory retention.

其實有幾種方法可以影響記憶留存範圍和效果。

For example, memories that are formed in times of heightened feeling, or even stress, will be better recorded due to the hippocampus's link with emotion.

例如，因為海馬體與情緒的連結，我們在強烈情緒或壓力下形成的情緒，將更有效地形成記憶。

But one of the major factors contributing to memory consolidation is... you guessed it, a good night's sleep.

但是記憶鞏固的主要因素是... 沒錯！正是一夜好眠。

Sleep is composed of four stages, the deepest of which are known as slow-wave sleep and rapid eye movement.

睡眠由四個階段組成，最深層的睡眠稱為「慢波睡眠期」和「快速眼動期」。

EEG machines monitoring people during these stages have shown electrical impulses moving between the brainstem, hippocampus, thalamus, and cortex, which serve as relay stations of memory formation.

腦電圖機器在監控人類睡眠階段時顯示，電脈衝遊走於腦幹、海馬迴、丘腦和皮質間，而這些部位都是記憶形成的中繼站。

And the different stages of sleep have been shown to help consolidate different types of memories.

而不同的睡眠階段也有助於鞏固不同類型的記憶。

During the non-REM slow-wave sleep, declarative memory is encoded into a temporary store in the anterior part of the hippocampus.

在非快速眼動、慢波睡眠期，陳述記憶被編譯，進入海馬體前端的暫存倉庫。

Through a continuing dialogue between the cortex and hippocampus, it is then repeatedly reactivated, driving its gradual redistribution to long-term storage in the cortex.

透過皮質和海馬體的持續對話，陳述記憶的活性被反覆激發，並逐漸被重新分配到皮質裡長期儲存。

REM sleep, on the other hand, with its similarity to waking brain activity, is associated with the consolidation of procedural memory.

另一方面，快速眼動期與清醒時的大腦活動相似，與鞏固程序記憶有關。

So based on the studies, going to sleep three hours after memorizing your formulas and one hour after practicing your scales would be the most ideal.

根據研究結果，背完公式三小時後、練琴一小時後入睡，能得到最理想的效果。

So hopefully you can see now that skimping on sleep not only harms your long-term health, but actually makes it less likely that you'll retain all that knowledge and practice from the previous night,

希望你能意識到，不睡覺不僅有損長期健康，還能導致記憶變差，更難記住你前一晚累積的知識和練習，

all of which just goes to affirm the wisdom of the phrase, "Sleep on it."

這些都在在地印證了俗諺所說的：「先睡一覺後再決定」。

When you think about all the internal restructuring and forming of new connections that occurs while you slumber,

當你想到睡著時，身體會進行的所有內在重建並形成新神經連結，

you could even say that proper sleep will have you waking up every morning with a new and improved brain, ready to face the challenges ahead.

你甚至可以斷言，適當睡眠能讓你每天早晨起床時有一顆清醒的頭腦，準備好面對眼前的挑戰。