會說外語好處多 雙語者大腦反應速度更快

核心提示：會說兩種語言的人會對提示的變化反應更快。

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

一項新研究發現，說兩種語言實際上能夠幫助消除衰老對大腦的影響。

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.

研究者測試了參與者們從一個認知活動轉換到另一個需要的時間。主管研究員布萊恩·古爾德是肯塔基大學的神經學家，他表示老年人轉換任務需要的時間更長。當他和ABCNews的記者在手機上說話時，他說自己正在一家蔬果店考慮到底是要買小富士蘋果還是美國青蘋果，這就日常生活中認知活動最典型的例子。

「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.」

「這個研究有重大的意義，因為我們的人口現在越來越老齡化了，」古爾德說。「老年人活的時間更長了，這是件好事，但是前提是他們的大腦要保持健康。」

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.

古爾德的團隊比較了年輕人和老年人轉換任務的速度，基於之前的研究，他們知道將得到的結果是老年人轉換任務的速度更慢。然而他們又發現，會說兩種語言的老年人轉換思維的速度要比只說一種語言的要快。

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.

研究的對象僅為一輩子都說兩種語言的人，一輩子說兩種語言在這個研究中的定義是：從10歲以前開始每天都使用第二種語言的人。

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，古爾德和他的團隊讓30個人看一系列有顏色的形狀，然後按下按鈕回答他們看到的是哪種形狀，這30個人中既有說一種語言也有會說兩種語言的人。然後，他們再給實驗參與者看類似的上了色的形狀，讓他們按按鈕回答他們看到形狀的顏色是什麼。最後，研究者們給參與者一系列有顏色的形狀，不過問題中既有讓參與者回答形狀的，又有讓他們回答顏色的，測試他們任務轉換所花的時間。

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

會說兩種語言的人會對提示的變化反應更快。

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.

研究者接著召集了80個人參與第二項實驗：20個說兩種語言的年輕人，20個說一種語言的年輕人，20個說兩種語言的老年人，以及20個說一種語言的老年人。這次，研究者用功能磁共振成像掃描法檢測參與者們參加同樣的實驗時大腦活動的情況。古爾德和他的團隊發現，說兩種語言的人不僅轉換任務的速度更快，而且他們大腦的活躍程度也同說一種語言的同齡人不同。

「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.

「這個研究讓我們看到，擁有不同認知處理能力的人，大腦是如何用不同方式處理同一個刺激物的。」克里斯蒂娜·維斯切如是說，她是阿拉巴馬大學醫學院一位神經學家，並沒有參與此次的研究。

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.」

維斯切將雙語稱為是一個「美麗的自然的實驗」。研究顯示，通過語言轉換、根據周圍的環境判斷應該如何回應，說著兩種語言長大的人能夠在認知方面得到某些特定的益處。肯塔基大學的研究者們又進了一步，用腦成像的方式進行實驗，維斯切說這種嘗試 「令人激動」。

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.

古爾德說他在蒙特利爾長大，在學校說法語，在家說英語。他的親戚也問他在法語的環境下長大是否會影響他學習英語的能力。

「Until very recently, learning a second language in childhood was thought of as dangerous,」 he said. 「Actually, it』s beneficial.」

「直到最近，人們還認為在童年學習第二門語言是危險的，」他說。「實際上，這樣做是有益的。」