March 29, 2012 – Adults may learn a language more like a native speaker in an immersion setting than by taking classes, according to a first-of-its kind series of brain studies by researchers at Georgetown University Medical Center (GUMC).
The latest study was published online in yesterday’s PLoS ONE by scientists at GUMC and the University of Illinois at Chicago.
“Only the immersion training led to full native-like brain processing of grammar,” says Michael Ullman, a GUMC professor of neuroscience and the studies’ senior investigator. “So if you learn a foreign language as an adult you can in fact come to use native language brain processes, but you may need immersion rather than classroom exposure.”
In the last few years, Ullman explains, research has suggested that adults learning a foreign language can come to rely on the same brain mechanisms as native speakers of a language.
“That might be true even for those parts of a foreign language that are particularly difficult to learn, such as its grammar,” the professor notes.
A Small Language
Ullman and Kara Morgan-Short (G’07) from the University of Illinois, who worked on the research with Ullman while she was a graduate student at Georgetown, first tested whether it matters under what conditions people learn a foreign language.
To test their theories, the researchers made up a very small language comprising 13 words.
The scientists found that after a few days, adults reached high proficiency at speaking and understanding the language, whether they had undergone classroom or immersion training.
But only the immersion group showed what Ullman calls “full native-like processing” of grammar in the brain.
Five months later and without having warned their study participants beforehand, the researchers called them back in for another round of brain scans.
“To our surprise, the participants actually became more native-like in their brain processing of grammar,” Ullman says.
Ullman believes that, over time, memory of the language “consolidates” in the brain, probably through the same mechanisms that also underlie native language.
He says the process is probably similar to the consolidation of many other skills, such as learning to ride a bike or play a musical instrument.
The participants showed neither improvements nor loss of proficiency during the same five-month period, even as their brains became more native-like, Ullman says.
The scientists say it is possible that proficiency changes might have been observed with more precise measures, or that improvements had occurred some time after training but were gradually lost in the absence of practice during the five-month period.
Ullman says that even without any observed changes in proficiency, the brain changes are important.
“Native language brain mechanisms are clearly well-suited to language, so attaining their use is a critical achievement for foreign language learners,” Ullman says. “We suspect that this should lead to improved retention of the language as well as higher proficiency over time.”