How does speaking multiple languages affect the brain?
27th July 2022
Speaking more than one language can bring many advantages, such as decreasing the chances of dementia, but occasionally the words, grammar and even accents can get mixed up. Let’s look at how being bilingual affects the brain.
How does a multilingual brain work?
The brain contains areas that deal with language, located in the perisylvian cortex of the left hemisphere. These areas are vital for performing language tasks and they are not the only areas that are used. Disparate parts of both right and left-brain hemispheres are active during language production. In multilingual individuals, there is a great deal of similarity in the brain areas used for each of their languages.
Research suggests that as you learn or regularly speak a second language, it becomes constantly “active” alongside your native language in your brain. The parallel activation of the two languages creates competition across the two languages, making the bilingual a ‘mental juggler’. Furthermore, keeping actively bilingual makes our brains more efficient at relaying information alongside increased cognitive control. This allows us to switch between the two languages and, at the same time, effectively select the intended language with relatively few errors.
A team of neuroscientists discovered that the brain uses a shared mechanism for combining words from a single language and for combining words from two different languages. Its findings show that language switching is natural for bilinguals because the brain has a mechanism that does not detect that the language has switched, allowing for a seamless transition in understanding more than one language at once.
“From research we know that as a bilingual or multilingual, whenever you’re speaking, both languages or all the languages that you know are activated. For example, when you want to say ‘dog’ as a French-English bilingual, not just ‘dog’ is activated, but also its translation equivalent, so ‘chien’ is also activated.”
Mathieu Declerck, senior research fellow at the Vrije Universiteit in Brussels
Issues with speaking multiple languages.
We already know that when a multilingual person wants to speak, the languages they know can be active at the same time, even if only one language gets used. This can sometimes cause issues. These languages can interfere with each other, for example intruding into speech, vocabulary, grammar and accent. This is less likely to be seen in proficient bilinguals who have acquired not only linguistic proficiency but also the cognitive skill that allows them to juggle the two languages with ease, but it’s not as rare as we think.
“Sometimes bilinguals will produce the right word, but with the wrong accent, which is a really interesting dissociation that tells you language control is being applied at different levels of processing,” she explained. “And there’s a separation between specification of accent, and specification of which lexicon you’re going to be drawing the words from.”
Tamar Gollan
Tamar Gollan has been studying language control in bilinguals for years. His studies found that a multilingual person’s dominant language can sometimes take a bigger hit than expected.
“I think maybe one of the most unique things that we’ve seen in bilinguals when they’re mixing languages is that sometimes, it seems like they inhibit the dominant language so much that they actually are slower to speak in certain contexts,” she says.
In one of her experiments, Gollan analysed the language-switching abilities of Spanish-English bilinguals. She asked them to read aloud paragraphs that were just in English, just in Spanish, and paragraphs that randomly mixed both English and Spanish.
The findings of the experiment were surprising. Even though participants (all of them dominant English speakers) had the texts right there in front of them, they would still make “intrusion errors” when reading aloud, for example, accidentally saying the Spanish word “pero” instead of the English word “but”. These errors happened when they were reading aloud the mixed-language paragraphs, which required switching between languages.
“I think the best analogy is, imagine that there’s some condition in which you suddenly become better at writing in your non-dominant hand,” she says. “We’ve been calling this reversed dominance, we’ve been making a really big deal out of it because the more I think about it, the more I realise how unique this is, and how crazy it is.”
Language interference.
While most bilinguals can keep can their native grammar in check, Kristina Kasparian, a writer, translator and consultant who studied neurolinguistics at McGill University in Montreal, Canada, said when people are immersed in a second language, it does impact the way they perceive and process their native language.
Final thoughts.
Researchers trust that a bilingual brain can compensate for brain deterioration by using alternative brain networks and connections when original pathways have been destroyed. This theory is called “cognitive compensation” and occurs because bilingualism promotes the health of both gray and white matter. Is it time to learn a new language?
References:
https://www.apa.org/science/about/psa/2008/01/kroll
https://www.pnas.org/doi/full/10.1073/pnas.1414183112
https://theconversation.com/keeping-actively-bilingual-makes-our-brains-more-efficient-at-relaying-information-36045
https://www.sciencedirect.com/science/article/abs/pii/B9780123943934000078
