What happens in the brain when you learn a second language?

Learning a foreign language can increase the size of your brain. This is what Swedish scientists discovered when they used brain scans to monitor what happens when someone learns a second language. The study is part of a growing body of research using brain imaging technologies to better understand the cognitive benefits of language learning. Tools like magnetic resonance imaging (MRI) and electrophysiology, among others, can now tell us not only whether we need knee surgery or have irregularities with our heartbeat, but reveal what is happening in our brains when we hear, understand and produce second languages. The Study showed that learning a foreign language has a visible effect on the brain. Young adult military recruits with a flair for languages learned Arabic, Russian or Dari intensively, while a control group of medical and cognitive science students also studied hard, but not at languages. MRI scans showed specific parts of the brains of the language students developed in size whereas the brain structures of the control group remained unchanged. Equally interesting was that learners whose brains grew in the hippocampus and areas of the cerebral cortex related to language learning had better language skills than other learners for whom the motor region of the cerebral cortex developed more. In other words, the areas of the brain that grew were linked to how easy the learners found languages, and brain development varied according to performance. As the researchers noted, while it is not completely clear what changes after three months of intensive language study mean for the long term, brain growth sounds promising. Looking at functional MRI brain scans can also tell us what parts of the brain are active during a specific learning task. This sort of research might eventually lead to advances in the use of technology for second-language learning. For example, using ultrasound machines like the ones used to show expectant parents the features and movements of their babies in the womb, researchers in articulatory phonetics have been able to explain to language learners how to make sounds by showing them visual images of how their tongue, lips, and jaw should move with their airstream mechanisms and the rise and fall of the soft palate to make these sounds. However we learn, this recent brain-based research provides good news. We know that people who speak more than one language fluently have better memories and are more cognitively creative and mentally flexible than monolinguals. Canadian studies suggest that Alzheimer’s disease and the onset of dementia are diagnosed later for bilinguals than for monolinguals, meaning that knowing a second language can help us to stay cognitively healthy well into our later years. Even more encouraging is that bilingual benefits still hold for those of us who do not learn our second languages as children. Edinburgh University researchers point out that “millions of people across the world acquire their second language later in life: in school, university, or work, or through migration or marriage.” Their results, with 853 participants, clearly show that knowing another language is advantageous, regardless of when you learn it.

Thanks to Alison Mackey - professor of linguistics - Georgetown University and Lancaster University.