Study shows bilinguals are unable to 'turn off' a language completely
August 18, 2009With a vast majority of the world speaking more than one language, it is no wonder that psychologists are interested in its effect on cognitive functioning. For instance, how does the human brain switch between languages? Are we able to seamlessly activate one language and disregard knowledge of other languages completely?
According to a recent study published in Psychological Science, a journal of the Association for Psychological Science, it appears humans are not actually capable of "turning off" another language entirely. Psychologists Eva Van Assche, Wouter Duyck, Robert Hartsuiker and Kevin Diependaele from Ghent University found that knowledge of a second language actually has a continuous impact on native-language reading.
The researchers selected 45 Ghent University students whose native-language was Dutch and secondary language was English. The psychologists asked the students to read several sentences containing control words — plain words in their native-language—and cognates. Cognates are words that have a similar meaning and form across languages, often descending from the same ancient language; for example, "cold" is a cognate of the German word "kalt" since they both descended from Middle English.
While the students read the sentences, their eye movements were recorded and their fixation locations were measured—that is, where in the sentence their eyes paused. The researchers found that the students looked a shorter period of time at the cognates than at the controls. So in the example sentence "Ben heeft een oude OVEN/LADE gevonden tussen de rommel op zolder" (Ben found an old OVEN/DRAWER among the rubbish in the attic"), the bilingual students read over "oven" more quickly than "lade."
According to the psychologists, it is the overlap of the two languages that speeds up the brain's activation of cognates. So even though participants did not need to use their second language to read in their native-language, they still were unable to simply "turn it off." It appears, then, that not only is a second language always active, it has a direct impact on reading another language—even when the reader is more proficient in one language than another.
Source: Association for Psychological Science (news : web)



I understand that native Russians use English extensively in technical work, for example computer programming. I've seen them switch, as soon as the conversation becomes technical.
The only difference is using the correct language for the correct situation. But with those cognates you are mixing the two.
If asked to spontaneously "switch" from one language to the other while talking, the exercise presents no difficulty whatsoever - as long as the "switch" is allowed to occur between complete sentences. This is what translators do anyway - not word for word, but entire sentences. It appears translators are spontaneously translating word for word, but they are not. They "know" the entire sentence to translate beforehand - analogous to hearing and recognizing an entire song from a few beginning notes.
I believe I view the verbal as well as the reading and writing worlds through parallelism - the authors have stated this differently, they call it "continuous impact" knowledge of a "second" language on reading. I went further here and stated subjectively, speech and writing are "impacted" as well.
Ending on a philosophical note, it would be wonderful if everyone were fluent in all languages, ending the worldwide grave conflicts and misunderstandings that arise through less-than-perfect fluency and translations.