研究生考試的腳步是越來越近了，各位考研學子們也都在努力提升自己的知識量，也都希望能夠在最後的幾天時間當中取得令人驚喜的成績。遇事不要慌，如何應對考試壓力？收好小妙招：提前模擬考試環境、體育鍛鍊、良好睡眠、深呼吸。
You spend weeks studying for an important test.
你花了好幾周時間準備一場重要的考試。
On the big day, you wait nervously as your teacher hands it out.
考試當天，你緊張地等待老師分發試題。
You're working your way through, when you're asked to define 'ataraxia.
你努力作答，看到一道題目要求解釋"ataraxia"。
' You know you've seen it before, but your mind goes blank.
你記得自己曾見過這個詞，但是大腦卻一片空白。
What just happened?
這是怎麼回事？
The answer lies in the complex relationship between stress and memory.
答案在於壓力與記憶之間存在複雜的聯繫。
There are many types and degrees of stress and different kinds of memory, but we're going to focus on how short-term stress impacts your memory for facts.
壓力的類型和程度多種多樣。記憶也是如此，但我們將集中探討短期壓力如何影響內容記憶。
To start, it helps to understand how this kind of memory works.
首先，我們先來理解這類記憶是如何工作的。
Facts you read, hear, or study become memories through a process with three main steps.
你讀到、聽到或學到的事實會經過三個主要步驟成為記憶。
First comes acquisition: the moment you encounter a new piece of information.
首先是信息獲取，即獲得新的信息。
Each sensory experience activates a unique set of brain areas.
每種感官體驗都會激活大腦特定的區域。
In order to become lasting memories, these sensory experiences have to be consolidated by the hippocampus, influenced by the amygdala, which emphasizes experiences associated with strong emotions.
為了形成長期記憶，這些感官體驗會經海馬體進行增強，並受到杏仁核的影響。杏仁核能夠強化帶有強烈情感的經驗。
The hippocampus then encodes memories, probably by strengthening the synaptic connections stimulated during the original sensory experience.
在這之後， 海馬體對記憶進行編碼，方法可能是通過加強感官體驗發生時建立的突觸連接。
Once a memory has been encoded, it can be remembered, or retrieved, later.
一旦記憶被編碼，它能夠在之後被記住和提取。
Memories are stored all over the brain, and it's likely the prefrontal cortex that signals for their retrieval.
記憶存儲區遍布大腦，很可能是由前額葉負責發出提取記憶的信號。
So how does stress affect each of these stages?
那麼壓力是如何影響這個過程的呢？
In the first two stages, moderate stress can actually help experiences enter your memory.
在前兩個階段，適度的壓力實際上可以幫助感官體驗進入記憶。
Your brain responds to stressful stimuli by releasing hormones known as corticosteroids, which activate a process of threat-detection and threat-response in the amygdala.
你的大腦會對壓力刺激做出反應，釋放出皮質類固醇激素，這會激活杏仁核中的威脅感知和威脅應對程序。
The amygdala prompts your hippocampus to consolidate the stress-inducing experience into a memory.
杏仁核會促使海馬體加強壓力引發的經驗進入記憶。
Meanwhile, the flood of corticosteroids from stress stimulates your hippocampus, also prompting memory consolidation.
同時壓力導致 皮質類固醇大量分泌，進一步刺激海馬體，有助於記憶鞏固。
But even though some stress can be helpful, extreme and chronic stress can have the opposite effect.
即便有些壓力是有用的，壓力過大或長期壓力都會適得其反。
Researchers have tested this by injecting rats directly with stress hormones.
研究者向老鼠直接注射壓力激素進行了實驗。
As they gradually increased the dose of corticosteroids, the rats' performance on memory tests increased at first, but dropped off at higher doses.
隨著皮質類固醇的劑量不斷增加，老鼠在記憶方面的表現先是增高，之後便隨劑量繼續增加而下降。
In humans, we see a similar positive effect with moderate stress.
對於人類而言，適度壓力起到了相似的積極作用。
But that only appears when the stress is related to the memory task— so while time pressure might help you memorize a list, having a friend scare you will not.
但是這隻表現在 與記憶相關的壓力上，因此時間壓力雖然能幫你提高記憶，但來自朋友的驚嚇則沒有這種效果。
And the weeks, months, or even years of sustained corticosteroids that result from chronic stress can damage the hippocampus and decrease your ability to form new memories.
慢性壓力會帶來的長達數周、數月甚至數年的皮質類固醇的持續分泌，會對海馬體造成傷害，並且削弱形成新記憶的能力。
It would be nice if some stress also helped us remember facts, but unfortunately, the opposite is true.
如果壓力能幫助記憶就好了，遺憾的是，事實恰恰相反。
The act of remembering relies on the prefrontal cortex, which governs thought, attention, and reasoning.
記憶行為依賴前額葉，它控制著思考，注意力和推理能力。
When corticosteroids stimulate the amygdala, the amygdala inhibits, or lessens the activity of, the prefrontal cortex.
當皮質類固醇刺激杏仁核，杏仁核會抑制或是減少前額葉的活動。
The reason for this inhibition is so the fight/flight/freeze response can overrule slower, more reasoned thought in a dangerous situation.
原因在於：在危險環境下，逃跑/戰鬥的應激反應優於速度更慢，需要推理的思考過程。
But that can also have the unfortunate effect of making your mind go blank during a test.
但這也帶來了不好的影響，它會讓你的大腦在考試時一片空白。
And then the act of trying to remember can itself be a stressor, leading to a vicious cycle of more corticosteroid release and an even smaller chance of remembering.
嘗試回憶會進一步產生壓力，從而導致分泌更多皮質類固醇，形成惡性循環，這讓想起答案的機率變得更小。
So what can you do to turn stress to your advantage and stay calm and collected when it matters the most?
那麼該如何讓壓力為你所用？如何在最重要的時刻保持鎮定和冷靜？
First, if you know a stressful situation like a test is coming, try preparing in conditions similar to the stressful environment.
首先，如果你了解壓力情境，例如即將到來的考試，你可以模擬相似的壓力環境做好準備。
Novelty can be a stressor.
因為新鮮體驗可能是一項壓力來源。
Completing practice questions under time pressure, or seated at a desk rather than on a couch, can make your stress response to these circumstances less sensitive during the test itself.
在時間限制下完成練習題目，或是坐在桌旁學習而不是沙發上，都可以讓你在考試時對這些壓力的敏感性降低。
Exercise is another useful tool.
體育鍛鍊也很有用。
Increasing your heart and breathing rate is linked to chemical changes in your brain that help reduce anxiety and increase your sense of well-being.
提高心跳和呼吸頻率會改變大腦中的化學物質，這能幫助你減少焦慮，提高幸福感。
Regular exercise is also widely thought to improve sleeping patterns, which comes in handy the night before a test.
規律的鍛鍊也被廣泛認為能改善睡眠，好的睡眠在考前一晚非常重要。
And on the actual test day, try taking deep breaths to counteract your body's flight/fight/freeze response.
到了考試當天，試著做深呼吸來平衡身體的應激反應。
Deep breathing exercises have shown measurable reduction in test anxiety in groups ranging from third graders to nursing students.
一項實驗證實深呼吸能有效減少考試焦慮，實驗對象從三年級學生到護理專業學生。
So the next time you find your mind going blank at a critical moment, take a few deep breaths until you remember ataraxia: a state of calmness, free from anxiety.
所以在下一次重要時刻大腦一片空白時，做幾次深呼吸直到你想起來ataraxia是什麼意思——一種平靜的，沒有焦慮情緒的狀態。