Some of the most important decisions of our lives occur while we're feeling stressed and anxious. From medical decisions to financial and professional ones, we are all sometimes required to weigh up information under stressful conditions. But do we become better or worse at processing and using information under such circumstances?

人一生中有些至关重要的决定，是在感到压力和焦虑时做出的。从医疗，到财务，再到职业方面的决定，我们有时都需要在有压力的情况下权衡信息。但在这种情况下，我们处理和运用信息的能力会变得更好还是更差呢?

My colleague and I, both neuroscientists, wanted to investigate how the mind operates under stress, so we visited some local fire stations. Firefighters' workdays vary quite a bit. Some are pretty relaxed; they'll spend their time washing the truck, cleaning equipment, cooking meals and reading. Other days can be hectic, with numerous life-threatening incidents to attend to; they'll enter burning homes to rescue trapped residents, and assist with medical emergencies. These ups and downs presented the perfect setting for an experiment on how people's ability to use information changes when they feel under pressure.

我和同事都是神经科学家，我们想研究大脑在压力下是如何运作的，于是我们走访了当地的一些消防站。消防员的工作日差异很大。有时相当轻松，就洗洗消防车、刷刷设备、做做饭和看看书。而其他时候则可能非常忙碌，要处理很好危及生命的事件，他们得进入着火的房屋营救被困居民，还有协助处理医疗紧急情况。这些工作中的起起落落，为我们研究人们在压力下运用信息的能力会如何变化提供了完美的场景。

We found that perceived threat acted as a trigger for a stress reaction that made the task of processing information easier for the firefighters – but only as long as it conveyed bad news.

我们发现，感知到的威胁会引发压力反应，有了这种反应，消防员更容易处理信息--但只有当这些信息是坏消息的时候才成立。

This is how we arrived at these results. We asked the firefighters to estimate their likelihood of experiencing 40 different adverse events in their life, such as being involved in an accident or becoming a victim of card fraud. We then gave them either good news (that their likelihood of experiencing these events was lower than they'd thought) or bad news (that it was higher) and asked them to provide new estimates.

我们得出这些结论的方式如下:我们让消防员估计他们在生活中经历40种不同不良事件的可能性，比如经历意外或成为遭遇信用卡诈骗。然后，我们给他们好消息(他们经历这些事件的可能性比自己想象的要低)，或坏消息(可能性比他们想象的要高)，并让他们重新估计。

People are normally quite optimistic – they will ignore bad news and embrace the good. This is what happened when the firefighters were relaxed; but when they were under stress, a different pattern emerged. Under these conditions, they became hyper-vigilant to bad news, even when it had nothing to do with their job (such as learning that the likelihood of card fraud was higher than they'd thought), and altered their beliefs in response. In contrast, stress didn't change how they responded to good news (such as learning that the likelihood of card fraud was lower than they'd thought).

人们通常相当乐观，会忽视坏消息而乐于接受好消息。消防员放松时会这样。但当他们有压力时，就会出现一种不同的(行为)模式。在这种情况下，他们对坏消息高度警惕，即便是听到与他们工作无关的坏消息(比如得知信用卡诈骗的可能性比他们想象的要高)，并且他们会据此改变自己的看法。相比之下，压力并没有改变他们对好消息的反应(比如得知自己遭遇信用卡诈骗的可能性比他们想象的要低)。

Back in our lab, we observed the same pattern in students who were told they had to give a surprise public speech, which would be judged by a panel, recorded and posted online. Sure enough, their cortisol levels spiked, their heart rates went up and they suddenly became better at processing unrelated, yet alarming, information about rates of disease and violence.

在实验室里，我们在学生身上也观察到了同样的模式。我们告诉这些学生，他们必须进行一场临时的公开演讲，这个演讲会由评审团评判、录制并发布到网上。果然，他们的皮质醇水平飙升，心率加快，而且突然能更好地处理关于疾病发生率以及暴力事件这种(与演讲本身)并无联系但令人担忧的信息。

When we experience stressful events, a physiological change is triggered that causes us to take in warnings and focus on what might go wrong. Brain imaging reveals that this 'switch' is related to a sudden boost in a neural signal important for learning, specifically in response to unexpected warning signs, such as faces expressing fear.

当我们经历有压力的事件时，会引发一种生理变化，从而使我们留意警示(信号)并关注可能出错的地方。大脑成像显示，这种“转换“与一种对学习很重要的神经信号的突然增强有关。尤其在面对突发的预警信号的时候，比如看到了表现出恐惧的面孔，会发生这种“转换”。

Such neural engineering could have helped prehistoric humans to survive. When our ancestors found themselves surrounded by hungry animals, they would have benefited from an increased ability to learn about hazards. In a safe environment, however, it would have been wasteful to be on high alert constantly. So, a neural switch that automatically increases or decreases our ability to process warnings in response to changes in our environment could have been useful. In fact, people with clinical depression and anxiety seem unable to switch away from a state in which they absorb all the negative messages around them.

这种神经机制可能曾帮助史前人类生存下来。当我们的祖先发现自己被饥饿的动物包围时，增强对危险的认知能力会对他们有益。然而，在安全的环境中，持续高度警惕就会是一种浪费。所以，一种能根据环境变化自动增强或减弱我们处理警告信息能力的神经转换机制可能会很有用。事实上，患有临床抑郁症和焦虑症的人似乎无法从那种吸收周围所有负面信息的状态中转换出来。

It is also important to realise that stress travels rapidly from one person to the next. If a co-worker is stressed, we are more likely to tense up and feel stressed ourselves. We don't even need to be in the same room with someone for their emotions to influence our behaviour. Studies show that if we observe positive feeds on social media, such as images of a pink sunset, we are more likely to post uplifting messages ourselves. If we observe negative posts, such as complaints about a long queue at the coffee shop, we will in turn create more negative posts.

同样重要的是要意识到，压力会在人与人之间迅速传递。如果一个同事感到有压力，我们自己也更有可能紧张起来并感到有压力。甚至不需要和别人在同一个房间里，他们的情绪也会影响我们的行为。研究表明，如果我们在社交媒体上看到积极的推送内容，比如粉色日落的图片，我们自己也更有可能发布积极向上的内容。如果我们看到负面的帖子，比如抱怨咖啡店排长队，进而我们自己也会发布更多负面的帖子。

In some ways, many of us now live as if we are in danger, constantly ready to tackle demanding emails and text messages, and respond to news alerts and comments on social media. Repeatedly checking your phone, according to a survey conducted by the American Psychological Association, is related to stress. In other words, a pre-programmed physiological reaction, which evolution has equipped us with to help us avoid famished predators, is now being triggered by an online post. Social media posting, according to one study, raises your pulse, makes you sweat, and enlarges your pupils more than most daily activities.

在某种程度上，我们很多人现在生活得好像我们处于危险之中，时刻准备着去处理棘手的电子邮件和短信，回应新闻警报和社交媒体评论。根据美国心理协会的一项调查，频繁查看手机与压力有关。换句话说，进化赋予我们了一种帮助我们躲避饥饿捕食者的预设生理反应，这种反应现在能被一条网上的帖子触发。根据一项研究，社交媒体发帖比大多数日常活动更能让人脉搏加速,出汗并放大瞳孔。

The fact that stress increases the likelihood that we will focus more on alarming messages, together with the fact that it spreads extremely rapidly, can create collective fear that is not always justified. After a stressful public event, such as a natural disaster or major financial crash, there is often a wave of alarming information in traditional and social media, which individuals become very aware of. But that has the effect of exaggerating existing danger. And so, a reliable pattern emerges – stress is triggered, spreading from one person to the next, which temporarily enhances the likelihood that people will take in negative reports, which increases stress further. As a result, trips are cancelled, even if the disaster took place across the globe; stocks are sold, even when holding on is the best thing to do.

压力会增加我们更可能关注预警信息，加上压力传播得极快，这可能会引发不合理的集体恐惧。在经历引起压力的公共事件后，比如自然灾害或重大金融危机，传统媒体和社交媒体上往往会出现大量令人担忧的信息，人们会非常关注这些信息。但这会夸大现有危险。于是，一种稳定模式(引申为常见循环)就出现了:压力被触发，人传人，短期内提高人们相信负面报道的可能性进而进一步加剧压力。结果就是，即使灾难远在地球另一端，人们也会取消旅行;即使持有股票最好，人们也会抛售。

The good news, however, is that positive emotions, such as hope, are contagious too, and are powerful in inducing people to act to find solutions. Being aware of the close relationship between people's emotional state and how they process information can help us frame our messages more effectively and become conscientious agents of change.

不过，好消息是，像希望这样的积极情绪也会相互感染，而且在促使人们行动起来寻找解决方案方面很有效。意识到人们的情绪状态和他们处理信息的方式之间有密切关系，能帮助我们更有效地组织信息，并成为负责的变革推动者。[注释]此处应指倒数第二段的循环是负面循环，我们应对信息的转播做好把控，减少因此而产生的循环和不良后果。