译者 秋风紫苑
Caffeine’s Effects On Your Thinking
咖啡因对思考的影响
Caffeine is the most widely consumed stimulant in the world. We drink it in our coffee, we consume it in our cans of Coke and Pepsi. People take in so much of this drug, they rarely think twice about it.
咖啡因是世界上消费最广泛地的刺激物。我们喝的咖啡、可乐中都含有咖啡因，人们服用这种药物如此之多，却很少去思考它。
Caffeine is found naturally in so many of our foods and beverages, we take it for granted. On top of that, it’s often referenced for its positive effects on attention and mental alertness.
咖啡因在我们很多食物和饮料中都含有，它经常被用来提高人们的注意力和提升精力的积极作用。
Not only is caffeine found abundantly available in natural and supplemented foods and beverages, you’ll also find it in products sold over the counter for fatigue, migraines and colds.
咖啡因不仅仅在丰富的天然和补给食物和饮料中发现，它还作为治疗疲劳、偏头痛和感冒的非处方药销售。
But what are caffeine’s effects on our thinking? Is it helping or hindering our thought processes? Let’s find out…
但是咖啡因在我们思考中起到什么作用呢？它能够帮助还是阻碍我们的思考？让我们去寻找答案。。。
Blood levels of caffeine peak in as few as 15 minutes and on average 45 minutes after ingestion. Some studies suggest that over 80 percent of U.S. adults and children ingest caffeine on a daily basis (Brunye et al., 2010).
当体内摄取了咖啡因后最少15分钟，平均45分钟血药浓度达到峰值。一些研究显示，每天都有超过80%的美国成人和儿童摄取咖啡因。
Many studies indicate that the primary role caffeine has affecting our behavior is its effect on blocking the inhibitory properties of endogenous adenosine. So what? you say. Well, that inhibition results in increased dopamine, norepinephrine and glutamate. Caffeine ingestion leads to increased stimulation of your heart (cardio) and even anti-asthmatic actions.
很多研究表明，影响我们行为的咖啡因最主要的作用是调节体内腺苷的抑制作用。那又怎么样呢？抑制的结果就是增加了体内的多巴胺、去甲肾上腺素和谷氨酸酯。摄取咖啡因还能增加对心脏（大脑）的刺激，甚至起到平喘作用。
Many studies have demonstrated that caffeine leads to enhanced cognitive performance involving various tasks (Brunye et al., 2010). It is often cited for its positive effects on vigilance, mental alertness, feeling of well-being and arousal. Caffeine also has a positive effect on various domains of attention (Trayambak et al., 2009).
很多研究还证明，咖啡因能够增强各种认知行为。它的积极作用经常被利用，如警觉性、提升精神，安宁和觉醒感等方面。咖啡因还有提高各种注意力的优点。
Many studies show caffeine reduces response times and error rates in simple reaction time tasks, choice reaction time, and visual vigilance. Your brain appears to love caffeine too. Brain processes that have also been shown to benefit from caffeine include visual selective attention, task switching, conflict monitoring and response inhibition.
很多研究还显示，在简单的反应时间测试、选择反应时间和视觉警惕方面，咖啡因能够降低反应时间和错误率。你的大脑似乎也爱咖啡因，大脑处理过程也会由咖啡因而受益，包括视觉选择注意力、任务开关、冲突追踪和对抑制的反应。
Different types of tasks are used when measuring caffeine’s effect on different types of attention. Sustained attention — e.g., attention over a prolonged time period — has been most studied. A large body of data shows caffeine positively influences sustained attention. Sustained attention often is measured by using a continuous performance task. For example, participants view a stream of stimuli (often letters) and are required to respond whenever a predetermined target is presented. Task length varies considerably.
衡量咖啡因在各种不同类型注意力中作用时，不同类型的测试被进行。持续的注意力（如注意力能延长一段时期）被研究的最多。大量的数据显示，咖啡因确定地对持续注意力有作用。持续注意力经常是通过利用一个连续的表演任务去衡量，例如，测试者看一串刺激物（经常是字母）并且要求在任何时候对一个预定目标出现时的反应，测试的时间长短不断变化。
Research also shows caffeine has positive effects on selective attention — the process of attending to meaningful sources while ignoring irrelevant ones. The research findings are indecisive; some research has failed to find a positive relationship between caffeine ingestion and selective attention.
研究还显示，咖啡因在选择注意力方面的积极作用--忽视无相关的东西，对有意义信息的注意过程。这项研究发现是非决定性的；一些研究未能发现在咖啡因摄取和选择注意力两者之间的正相关。
Selective attention most often is measured by four main tasks. The visual search task is least often used to measure caffeine’s effects on selective attention.
选择注意力经常通过四个主要任务测试的，视觉搜索测试很少被用来测试咖啡因对选择注意力的影响。
A visual search task consists of participants identifying a predetermined target stimulus while ignoring a number of distractors. For example, a conjunction search requires participants to identify a target by at least two different attributes (e.g., find a blue capitalA). These types of tasks are useful because in daily life, often it is necessary to identify objects by several attributes.
视觉搜索任务是由测试者识别一个预定目标刺激物，而忽略大量错误选择。例如，一个联合搜索要求测试者通过至少两个不同的特征（例如发现一个蓝色的大写字母A）去识别一个目标，这些类型的任务是有用的，因为在日常生活中，必须经常需要通过各种特征去识别一个物体。
Moderate doses of caffeine — 200-300 mg — often are used in research, although doses over 500 mgs sometimes are used. The general finding is that more than moderate use does not offer additional benefits, and higher doses sometimes lead to negative effects.
尽管有时候超过500mg的剂量在研究中被应用，但适量的咖啡因--200~300mg--经常在研究中应用。研究发现，超过常量摄取咖啡因也不会增加益处，并且高剂量还会导致副作用。
So go ahead and have that cup of coffee or can of Coke. It’s likely to help your thinking… as long as you don’t overdo it.
因此，去冲杯咖啡或者喝罐可乐，它很可能会对你的思考有帮助，只要你不要喝得过多。
from 译言-每日精品译文推荐 http://article.yeeyan.org/view/307957/268045