Expats who arrive in a new country unable to speak the language can obtain a near native level if they immerse themselves in it, scientists believe.

The way an adult learns a foreign language can affect the way their brain processes the language so those who undergo immersion, where they are completely surrounded by language examples, tend to have brain processes similar to that of native speakers, according to a study by scientists in the United States and Brazil.
‘We have confirmed that adults learning a foreign language can come to rely on the same brain mechanisms as native speakers of a language, and that this could be true even for those parts of a foreign language that are particularly difficult to learn, such as its grammar,’ said Michael Ullman, a professor of neuroscience at Georgetown University in Washington DC.
Along with Kara Morgan of the department of Hispanic and Italian studies at the university of Illinois at Chicago and Ingrid Finger of the department of modern languages at the Federal University of Rio Grande do Sul, Porto Alegre, Brazil , he tried to find out whether classroom methods with many explanations of grammar was better or not than immersion learning where there are no grammar examples but lots of language examples.

They concluded that adults can achieve native like knowledge of grammar through immersion but they are not entirely sure why.

Previous studies have found that classroom exposure results in better learning than immersion. However no studies have looked at the brain mechanisms after different types of learning.

Those taking part were taught a simple, made up language Brocanto2, with grammar rules similar to actual languages but different from their native English. The results showed that only immersion led to full native like brain processing of grammar.
‘Native language brain mechanisms are clearly well suited to language, so attaining their use is a critical achievement for foreign language learners. We suspect that this should lead to improved retention of the language as well as higher proficiency over time. So if you learn a language you can come to use native language brain processes, but you may need immersion rather than classroom exposure,’ said Ullman.
The study also looked at whether people who achieve a high proficiency in a foreign language forget it if they don’t then use it regularly.

The researchers called the study participants back five months after the end of the study, without prior warning. Because the language was made up, the scientists were sure participants had not used it in those five months.

The results were quite surprising in that participants became more native like in their brain processing of grammar. This was true of both classroom and immersion groups. Though only the immersion group showed full native processing.

Ullman believes that, over time, memory of the language was consolidated in the brain. He says this process is probably similar to the consolidation of many other skills that a person might learn, such as learning to ride a bike or play a musical instrument.

Although learning a second language as an adult is notoriously difficult, research has shown that adults can indeed attain native language like brain processing and high proficiency levels. One reason why immersion learning leads to more native like attainment could be because it exposes learners to more meaningful phrases and sentences, the scientists said.
‘The possibility that explicit (classroom style) training may retard the development of native like grammatical processing is intriguing, and warrants further examination. It suggests that even though explicit training might provide early advantages, its longer term consequences may not be so beneficial,’ their study concludes.