Exact statistics are hard to come by, but it is generally accepted that a majority of the world’s population speaks more than one language. In the U.S., census data shows that about 20 percent of people speak a language other than English at home. That number has been steadily growing, but it doesn't account for all the people who learned a foreign language in school, or for some other purpose.
With that in mind, if we want to better understand how the brain works, how it processes sound and language, it might be a good idea to study the brains of bilingual people. In Northwestern’s Bilingualism and Psycholinguistics Laboratory, Dr. Viorica Marian is concerned with doing just that. The lab does research examining the differences of bilingual people in learning and memory from those with a single language.