New research looked into how people who speak different languages process them in the brain.
ADVERTISEMENTPeople who speak more than five languages, known as polyglots, light up in the “language network” of the brain when they listen to languages that they speak, with stronger responses to the ones they are most proficient in.
However, according to a new study, when listening to their native tongues, the brain’s activity was either similar or dropped off compared to non-native languages they were fluent in.
“Something makes it a little bit easier to process - maybe it’s that you’ve spent more time using that language - and you get a dip in activity for the native language compared to other languages that you speak proficiently,” Evelina Fedorenko, an associate professor of neuroscience at the Massachusetts Institute of Technology (MIT) and senior author of the study, said in a statement.
While many people globally speak more than one language fluently, few people speak five or more languages, the authors said, and most research has focused on bilinguals.
They argue that this limits studies to asking only about two languages and comparing someone’s “privileged” native tongue to a single non-native language, which is why they turned to polyglots.
How did the study work?
The researchers in the US used functional magnetic resonance imaging (fMRI) to scan the brains of 34 polyglots and published their findings in the scientific journal Cerebral Cortex.
All of the participants had some proficiency in five or more languages but most began learning them as teenagers or adults.
Sixteen of the participants were “hyperpolyglots” meaning they spoke 10 or more languages, including one person who had at least some proficiency in 54 languages. The mean number of languages spoken or signed among participants was around 15.
The polyglots listened to texts from either the Bible or Alice in Wonderland read in eight different languages.
These included texts in their native languages, a language they were fluent in, one in which they were moderately proficient, and another in which they were less fluent.
They also listened to languages they did not speak, including those in the same family as a language they know and others that were completely unrelated.
Researchers looked at their brains’ “language network,” which is interconnected areas of the brain’s frontal and temporal lobes that are known to support language processing.
What did the scans show?
The language network, primarily on the left side of the brain, lit up the most when the participants listened to passages from languages in which they were most fluent, except for their native languages.
“As you increase proficiency, you can engage linguistic computations to a greater extent, so you get these progressively stronger responses,” Fedorenko said.
“But then if you compare a really high-proficiency language and a native language, it may be that the native language is just a little bit easier, possibly because you've had more experience with it”.
When participants listened to the languages they did not speak, the brain similarly responded more to languages that were related to ones they already knew.
Some limitations of the current study were that language proficiency was self-reported and that they did not assess how well people understood the texts.
The authors plan to carry out further research on people who learned multiple languages at a very young age, including people who immigrated and became less proficient in their native tongue.
