How does multilingualism affect the mind?

Today, the majority of the world's professional population speaks at least two languages. American psycholinguist Viorica Marian states: "It would help to understand how the multilingual mind works, because that is very likely to be the future of humanity, especially if artificial languages and other symbolic systems are considered."

Marian, a pioneer in the field of psycholinguistics, has been studying multilingual brains since the 1990s. "People who speak more than one language or dialect have different linguistic, cognitive and neural structures than people who speak only one language,” She explains. "Studying the mind abstractly, as if it were monolingual, is a missed opportunity and gives us the wrong idea of how the mind works." 

In her book "The Power of Language: Multilingualism, Self and Society", Marian sets out five functional differences between bilingual and multilingual brains, regarding memory, decision-making, creativity, and other aspects.

1. Multilinguals may have different personalities in different languages.

People who are fluent in more than one language often feel as though different aspects of their personality come through more strongly depending on which language they use.

For Marian, this phenomenon was directly evident in her ability to write her book. The author, who grew up in Moldova speaking Romanian and Russian, said she could not imagine writing "The Power of Language" in any language other than English, which she learned in school.

"There is a professional aspect to it, of course, as I don't have the vocabulary to talk about neuroscience and cognitive science in Romanian and Russian," she says. "But there is also this personal connection, where language functions as a vehicle for culture. And Romanian culture - and South Eastern European culture in general - still has some way to go in terms of the representation of women in science."

In this way, the English language liberates Marian from the constraints of her mother tongue, empowering her to embody the roles of “thinker, writer and scientist”. A different language, then, has allowed greater expression.

2. A multilingual brain processes all languages everywhere and all the time.

A multilingual brain processes all languages in parallel, keeping them co-activated all the time.

"When the brain processes language, it's not just one place in the brain," says Marian. "It's a network that spans all areas of the brain."

That's why bilingual brains have more pathways connecting different words, concepts and memories in different languages. For example, the word for nail in French is "clou". Thus, a French-English bilingual will see more similarities between unrelated words like "nail" and "cloud" than someone who only speaks English would. This network also means that if one part of the brain is damaged, one language may be more affected than another. Marian compares it to an orchestra that has lost an instrument.

"If you damage a part of the brain, just as if you remove a musician from the orchestra, some pieces of music are more affected than others," she explains. "A piece that is more dependent on the violin will be more affected by the absence of the violinist than a piece that is less dependent on the violinist.

3. Multilinguals are more creative and have more capacity for divergent thinking than monolinguals.

The essence of creativity is the brain making connections between seemingly unrelated things. This is how inspiration for art, music, writing and even creative problem solving is born.

Because a multilingual person has more of these connections in their brain across different languages and cultures, they tend to perform better at creative tasks. 

"The constant coactivation of several languages strengthens the links between sounds, letters and words in a bilingual's mind, resulting in denser networks and stronger connections at the level of concepts and meanings," writes Marian.

4. Memories are stored and recalled differently in a bilingual or multilingual mind.

"Different neural networks are activated depending on the language, and with that activation, different memories come to mind," explains Marian. "So language changes because it is very much linked to culture, memory and personal experiences.

This is also true in the academic world. For example, if a Spanish-English bilingual is tested in English on something he or she has learned in Spanish, his or her performance will be worse than if the language of learning matches the language of the test.

5. Learning a different language can help your brain to age better.

Speaking different languages exercises the brain, which may ultimately protect it from some forms of cognitive decline.

Research has shown that older adults who know more than one language have  better memory, and population studies have found that multilingual countries have fewer cases of Alzheimer's disease.

According to another study, knowing more than one language can delay Alzheimer's and other types of dementia by four to six years on average. And the good news is that once you know a language, you don't even need to use it regularly to get cognitive benefits.

Marian agrees, stating "If you're thinking about skills or ways to invest your time, learning another language can be a really useful way to get long-term benefits as we age.”