听力文摘：我们只用了大脑的10%吗（在线收听）

Have you ever heard that we humans use only ten percent of our brains? This oft-quoted myth holds a certain appeal because if it were true, then we could instantly become ten times more intelligent just by firing up that sleepy majority of the brain!

你是否曾经听说过我们人类只使用了大脑的百分之十？这个被经常引用的神话般的说法颇具吸引力，因为如果这种说法属实，那么我们只要激活沉睡的大部分大脑就可以比现在聪明十倍！

Animals Experiments

动物实验

The idea that we use only a small fraction of the brain dates back to animal experiments in the 19th century. When scientists stimulated a specific part of the brain, the animal moved its leg or tail. If a tiny part of the brain could do something so grand, what was the use of the rest of the brain? Some scientists assumed (rather unscientifically) that large parts of the brain were simply useless.

人类只使用了大脑很小一部分的观点可以追溯到19世纪的动物实验。当科学家刺激动物大脑的某个特殊部分时，动物的腿部或尾巴就会动弹。如果大脑这微小的一部分就可以引起这么大的动作，那么大脑其它部分有什么作用呢？一些科学家则假设（其实相当不科学）大脑的大部分没有任何作用。

Then, in the early 20th century, scientists observed that stimulating certain regions of the brain had no physical effects. They dubbed these seemingly useless parts of the brain the “silent cortex.” Today we know that in humans, much of the “silent cortex” is actually devoted to complex activities like language, learning, and imagining.

到了20世纪早期，科学家观察到，刺激动物大脑某个区域其身体没有任何反应。于是他们把这部分看起来无用的大脑称作“沉默的皮质”。如今我们都知道，在人类大脑中，许多“沉默的皮质”实际上在一些复杂活动诸如语言、学习和想象等方面发挥着重要的作用。

Brain Scans

脑部扫描

Brain scans have shown that different parts of the brain crackle into heightened activity as we shift our attention and focus, but even as we sleep, many areas of the brain are extremely active. Would you be smarter if your entire brain constantly worked to maximum capacity? Interestingly enough, the opposite is probably true. The less brain activity you need to perform a given task, the more the brain as a whole is capable of doing.

脑部扫描表明，当我们转移注意力或聚精会神时，大脑不同部位顿时提高活动强度，即使我们睡觉时，大脑的许多区域也极其活跃。如果整个大脑充分持续运转，人是否就会更聪明？有趣的是，结果恰恰相反。执行一项既定任务时脑部活动越少，大脑作为一个整体能做的事情就越多。