关于睡眠状态下的人类大脑活动仍有许多待我们研究的地方，不过梦也许能给我们提供一些相关线索。本文探讨大脑学习外语的方式及梦里用外语交流对语言学习有何意义。

　　词汇：language learning 语言学习

　　It is often said that if we dream in a foreign language, it's a sign that we are making progress in learning that language. But is it true?

　　Before we can look at multilingual dreams, first we need to look at sleep. The link between sleep and language can be applied to how we learn any language, including our mother tongue. Even adults still learn about one new word every two days in their first language, but, if we are going to have a firm grasp of that new word, we need to link it to our existing knowledge. And in order to do that, we 'need to have some sleep', says Gareth Gaskell, a psychology professor at the University of York.

　　It's during sleep that the integration of old and new knowledge happens. At night, one part of our brain – the hippocampus – takes whatever new information it soaked up in the day, and passes it on to other parts of the brain to be stored. The role that dreams play in this night-time learning process is still being studied, but 'it's entirely possible that during multilingual dreams, the brain is trying to connect two languages', says Marc Züst, researcher at the University Hospital of Old Age Psychiatry and Psychotherapy in Bern, Switzerland.

　　So having multilingual dreams could mean that our brain is trying to master a new word or phrase, for example, but it could also have an emotional significance. Danuta Gabry?-Barker, a professor of psycholinguistics at the University of Silesia in Poland, suggests that multilingual dreams can express 'fears and desires' around learning a foreign language, including the wish to be a native-like speaker or to be accepted within a certain community.

　　We clearly still have a lot to learn about multilingual dreams, but one thing seems certain: if you're trying to learn a new language, you should definitely sleep on it.

　　词汇表

　　make progress 进步

　　multilingual 使用多种语言的

　　apply to 适用

　　mother tongue 母语

　　firm grasp of 牢牢掌握

　　existing knowledge 已有知识

　　integration 融合

　　hippocampus 海马体

　　soak up 吸收（信息）

　　store 储存

　　learning process 学习过程

　　master 学习，掌握

　　significance 重要意义

　　psycholinguistics 心理语言学

　　express 表达

　　desire 渴望，愿望

　　native-like 像母语人士一样的，地道的

　　sleep on it “睡一觉再考虑”，考虑清楚再决定