第四篇：The Bilingual Brain

　　When Karl Kim immigrated to the United States from Korea as a teenager, he had a hard time learning English. Now he speaks it fluently, and he had a unique opportunity to see how our brains adapt to a second language. As a graduate student, Kim worked in the lab of Joy Hirsch, a
　　neuroscientist in New York. 1 They found evidence that children and adults don't use the same parts of the brain when they learn a second language.
　　The researchers used an instrument called an MRI ( magnetic resonance imaging) scanner to study the brains of two groups of bilingual people 2 . The other consisted of people who, like Kim, learned their second language later in life.People from both groups were placed inside the MRI scanner. This allowed Kim and Hirsch to see which parts of the brain were getting more blood and were more active. They asked people from both groups to think about what they had done the day before, first in one language and then the other. They couldn't speak out loud because any movement would disrupt the scanning.
　　Kim and Hirsch looked specifically at two language centers in the brain, Broca's area, which is believed to control speech production, and Wernicke's area, which is thought to process
　　meaning. Kim and Hirsch found that both groups of people used the same part of Wernicke's area no matter what language they were speaking. 3
　　People who learned a second language as children used the same region in Broca's area for both their first and second languages. People who learned a second language later in life used a different part of Broca's area for their second language. 4 Hirsch believes that when
　　language is first being programmed in young children, their brains may mix the sounds and
　　structures of all languages in the same area. Once that programming is complete, the processing of a new language must be taken over by a different part of the brain. 
　　A second possibility is simply that we may acquire languages differently as children than we do as adults. Hirsch thinks that mothers teach a baby to speak by using different methods involving touch, sound, and sight. 5
　　
 

　　
　　注释： 
　　1．Now he speaks it fluently，and he had a unique opportunity to see how our brains adapt to a
　　second language：现在他英语讲得很流利，并且有一个独特的机会来审视我们的大脑是如何适应第二语言的。adapt to：适应。
　　2．MRI(magnetic resonance imaging)：核磁共振成像
　　3．Broca’S area＆Wernicke’S area：Broca’s area,即布洛卡区，也译为布罗卡区，是大脑的一区，它主管语言信息的处理、话语的产生。Wemicke’s area，即韦尼克区，也译为威尼克区，是大脑写中枢，视觉性语言中枢。Broca’s area与Wernicke’s area共同形成语言系统。布洛卡区与韦尼克区通常位于脑部的优势半脑(通常位于左侧)，这是由于大多数人(97％)是右利的缘故。1861年法国神经学家兼外科医生保罗•布洛卡(Paul Broca,1824--1880)对一些失语症患者进行研究及治疗时发现此一区域，位于大脑皮层额下回后部的441区,45区，故以发现者的名字命名为布洛卡区。
　　练习：
　　A But their use of Broca's area was different.
　　B One group consisted of those who had learned a second language as children.
　　C How does Hirsch explain this difference?
　　D We use special parts of the brain for language leaming.
　　E And that is very different from learning a language in a high school or college class.
　　F Their work led to an important discovery.