会说外语好处多：双语者大脑反应速度更快

Speaking two languages can actually help offset some effects of aging on the brain, a new study has found.

一项新研究发现，说两种语言实际上能够帮助消除衰老对大脑的影响。

Researchers tested how long it took participants to switch from one cognitive task to another, something that’s known to take longer for older adults, said lead researcher, Brian Gold, a neuroscientist at the University of Kentucky. As he spoke to ABCNews.com from his cell phone, he said he was also in a grocery store choosing between gala and granny smith apples — a perfect example of switching between cognitive tasks in everyday life.

研究者测试了参与者们从一个认知活动转换到另一个需要的时间。主管研究员布莱恩·古尔德是肯塔基大学的神经学家，他表示老年人转换任务需要的时间更长。当他和ABCNews的记者在手机上说话时，他说自己正在一家蔬果店考虑到底是要买小富士苹果还是美国青苹果，这就日常生活中认知活动最典型的例子。

“It has big implications these days because our population is aging more and more,” Gold said. “Seniors are living longer, and that’s a good thing, but it’s only a good thing to the extent that their brains are healthy.”

“这个研究有重大的意义，因为我们的人口现在越来越老龄化了，”古尔德说。“老年人活的时间更长了，这是件好事，但是前提是他们的大脑要保持健康。”

Gold’s team compared task-switching speeds for younger and older adults, knowing they would find slower speeds in the older population because of previous studies. However, they found that older adults who spoke two languages were able to switch mental gears faster than those who didn’t.

古尔德的团队比较了年轻人和老年人转换任务的速度，基于之前的研究，他们知道将得到的结果是老年人转换任务的速度更慢。然而他们又发现，会说两种语言的老年人转换思维的速度要比只说一种语言的要快。

The study only looked at life-long bilinguals, defined in the study as people who had spoken a second language daily since they were at least 10 years old.

研究的对象仅为一辈子都说两种语言的人，一辈子说两种语言在这个研究中的定义是：从10岁以前开始每天都使用第二种语言的人。

First, Gold and his team asked 30 people, who were either bilingual or monolingual, to look at a series of colored shapes and respond with the name of each shape by pushing a button. Then, they presented the participants with a similar series of colored shapes and asked them to respond with what colors the shapes were by pushing a button. Finally, researchers presented participants with a series of colored shapes, but they mixed prompts for either a shape or a color to test participants’ task-switching times.

首先，古尔德和他的团队让30个人看一系列有颜色的形状，然后按下按钮回答他们看到的是哪种形状，这30个人中既有说一种语言也有会说两种语言的人。然后，他们再给实验参与者看类似的上了色的形状，让他们按按钮回答他们看到形状的颜色是什么。最后，研究者们给参与者一系列有颜色的形状，不过问题中既有让参与者回答形状的，又有让他们回答颜色的，测试他们任务转换所花的时间。

The bilingual people were able to respond faster to the shifting prompts.

会说两种语言的人会对提示的变化反应更快。

Researchers then gathered 80 more people for a second experiment: 20 young bilinguals, 20 young monolinguals, 20 old bilinguals, and 20 old monolinguals. This time, researchers used fMRI scans to monitor brain activity during the same shape- and color-identifying tasks. Gold and his team found that bilingual people were not only able to switch tasks faster — they had different brain activity than their monolingual peers.

研究者接着召集了80个人参与第二项实验：20个说两种语言的年轻人，20个说一种语言的年轻人，20个说两种语言的老年人，以及20个说一种语言的老年人。这次，研究者用功能磁共振成像扫描法检测参与者们参加同样的实验时大脑活动的情况。古尔德和他的团队发现，说两种语言的人不仅转换任务的速度更快，而且他们大脑的活跃程度也同说一种语言的同龄人不同。

“It allows a sort of window into how the brains of people who have different cognitive processing abilities are processing the same stimuli in different ways,” said Kristina Visscher, a neurobologist at the University of Alabama School of Medicine who did not work on the study.

“这个研究让我们看到，拥有不同认知处理能力的人，大脑是如何用不同方式处理同一个刺激物的。”克里斯蒂娜·维斯切如是说，她是阿拉巴马大学医学院一位神经学家，并没有参与此次的研究。

Visscher called bilingualism a “beautiful natural experiment”, because people grow up speaking two languages, and studies have shown that they reap certain cognitive benefits from switching between languages and determining which to respond with based on what’s going on around them. The University of Kentucky researchers took it a step further by using brain imaging, which she said was “exciting.”

维斯切将双语称为是一个“美丽的自然的实验”。研究显示，通过语言转换、根据周围的环境判断应该如何回应，说着两种语言长大的人能够在认知方面得到某些特定的益处。肯塔基大学的研究者们又进了一步，用脑成像的方式进行实验，维斯切说这种尝试 “令人激动”。

Gold said he grew up in Montreal, where he spoke French at school and English at home, prompting relatives to question whether his French language immersion would somehow hinder his ability to learn English.

古尔德说他在蒙特利尔长大，在学校说法语，在家说英语。他的亲戚也问他在法语的环境下长大是否会影响他学习英语的能力。

“Until very recently, learning a second language in childhood was thought of as dangerous,” he said. “Actually, it’s beneficial.”

“直到最近，人们还认为在童年学习第二门语言是危险的，”他说。“实际上，这样做是有益的。”