压力是如何影响你的记忆力的？How does stress affect your memory?

压力是如何影响你的记忆力的？How does stress affect your memory?
You spend weeks studying for an important test.
你花费了几周的时间准备一场重要的考试。
On the big day, you wait nervously as your teacher hands it out.
到了那个重要的日子，你紧张地等待着老师发下试卷。
You're working your way through, when you're asked to define 'ataraxia.'
当你正努力做题时，突然被要求解释‘无扰’是什么意思。
You know you've seen it before, but your mind goes blank.
你记得以前见过这个词，但一时却想不起来了。
What just happened?
刚才发生了什么？
The answer lies in the complex relationship between stress and memory.
答案隐藏在压力与记忆之间的复杂联系中。
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.
压力与记忆各有多种类型和程度，也存在不同种类的记忆力。但我们接下来主要探讨的是，短期压力如何影响你对事实的记忆。
To start, it helps to understand how this kind of memory works.
要开始，先理解这类记忆是如何工作的会有帮助。
Facts you read, hear, or study become memories through a process with three main steps.
你阅读、倾听或学习的事实，通过一个三个主要步骤的过程，成为记忆。
First comes acquisition, the moment you encounter a new piece of information.
首先是吸收阶段：即你遇到新信息的那一刻。
Each sensory experience activates a unique set of brain areas.
每种感官体验都能唤醒大脑中一系列特定的区域。
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.
要转化为长久记忆，这些感官体验需要通过海马体来巩固，并受到杏仁核的作用，后者会突出那些与强烈情感相关的体验。
The hippocampus then encodes memories, probably by strengthening the synaptic connections stimulated during the original sensory experience.
然后，海马体通过加强在最初感官体验期间激活的突触连接来编码记忆。
Once a memory has been encoded, it can be remembered, or retrieved, later.
一旦记忆被编码后，随后就可以被回忆或提取。
Memories are stored all over the brain, and it's likely the prefrontal cortex that signals for their retrieval.
记忆遍布大脑各处，而前额叶皮层很可能是负责发起提取这些记忆的信号。
So how does stress affect each of these stages?
那么，压力会对这些阶段产生什么影响呢？
In the first two stages, moderate stress can actually help experiences enter your memory.
在最初的两个阶段，适度的压力其实能帮助这些经历被记住。
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.
当你的大脑遇到压力刺激时，会释放一种名为皮质类固醇的激素，这种激素会在杏仁核中触发威胁侦测和响应的过程。
The amygdala prompts your hippocampus to consolidate the stress-inducing experience into a memory.
杏仁核会激发海马体，让其把引发压力的经历巩固成记忆。
Meanwhile, the flood of corticosteroids from stress stimulates your hippocampus, also prompting memory consolidation.
与此同时，压力引发的皮质类固醇激增也刺激了海马体，促使记忆得以巩固。
But even though some stress can be helpful, extreme and chronic stress can have the opposite effect.
然而，尽管适度压力可能对我们有所帮助，极度的和长期的压力却可能带来完全相反的效果。
Researchers have tested this by injecting rats directly with stress hormones.
研究者们通过直接给大鼠注射压力荷尔蒙来测试这一点。
As they gradually increased the dose of corticosteroids, the rats' performance on memory tests increased at first, but dropped off at higher doses.
随着对大鼠注射的皮质类固醇剂量逐步增加，它们在记忆力测试中的表现初期有所提升，但当剂量增至较高时性能却有所下降。
In humans, we see a similar positive effect with moderate stress.
在人类中，我们也观察到适度的压力带来了相似的积极效果。
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.
但这种积极效果仅在压力与记忆任务相关的情况下才会显现——因此，时间压力或许能帮助你记忆清单，但朋友的惊吓却无济于事。
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.
而由慢性压力引发的长期皮质类固醇积累，可能持续数周、数月甚至数年，这会对海马体造成损害，进而降低你形成新记忆的能力。
It would be nice if some stress also helped us remember facts, but unfortunately, the opposite is true.
如果某些压力同样能帮助我们记忆事实就好了，但遗憾的是，实际情况正相反。
The act of remembering relies on the prefrontal cortex, which governs thought, attention, and reasoning.
记忆的过程依靠前额叶皮层，这一区域负责思考、注意力和推理。
When corticosteroids stimulate the amygdala, the amygdala inhibits, or lessens the activity of, the prefrontal cortex.
当皮质类固醇激活杏仁核时，杏仁核便会抑制或降低前额叶皮层的活跃度。
The reason for this inhibition is so the fight/flight/freeze response can overrule slower, more reasoned thought in a dangerous situation.
这种抑制是为了在危险情况下让战斗、逃避或僵住的反应能够优先于较慢、更加理性的思考过程。
But that can also have the unfortunate effect of making your mind go blank during a test.
但这也可能导致你在考试时脑海一片空白，产生不良影响。
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.
而且，试图回忆本身就可能成为一种压力因素，导致皮质醇持续释放增多，进而陷入一个恶性循环，使得回忆的可能性更加渺茫。
So what can you do to turn stress to your advantage and stay calm and collected when it matters the most?
那么，怎样才能在最重要的时刻，把压力化为助力，保持冷静和从容呢？
First, if you know a stressful situation like a test is coming, try preparing in conditions similar to the stressful environment.
首先，如果你知道即将遭遇像考试这样的压力情境，试着在与考试环境相似的条件下做准备。
Novelty can be a stressor.
新奇也可能成为压力的来源。
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.
在有时间限制的情况下做练习题，或是选择坐在桌前而非沙发上进行学习，能够在考试时让你对这些情境的压力反应更为迟钝。
Exercise is another useful tool.
运动也是一种有效的方法。
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.
提高心率和呼吸频率能促进大脑中的化学变化，这有助于缓解焦虑感并提升幸福感。
Regular exercise is also widely thought to improve sleeping patterns, which comes in handy the night before a test.
人们普遍认为，定期进行体育锻炼能够改善睡眠习惯，尤其在考试前夜特别有益。
And on the actual test day, try taking deep breaths to counteract your body's flight/fight/freeze response.
在考试当天，试着做深呼吸来对抗你身体的“战斗、逃避或冻结”的反应。
Deep breathing exercises have shown measurable reduction in test anxiety in groups ranging from third graders to nursing students.
从三年级学生到护理学生等不同年龄段的群体中，深呼吸的练习已经被证实能显著降低考试焦虑。
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.
因此，当下次你在紧要关头发现自己心神一片空白时，不妨深呼吸几次，直到你体会到‘无扰’的境界：那是一种远离焦虑、心境平和的状态。