London - Forget brain training games or playing Sudoku, the best way to keep your brain sharp is by learning a new language.
Bilingual people are able to process information more efficiently than those who only speak a single language, according to brain scans.
And experts claim it is because multilinguists are skilled in filtering out words, or unnecessary information, when choosing which language they need to respond in.
Study lead author Doctor Viorica Marian, a professor at Northwestern University, said: “It’s like a stop light - bilinguals are always giving the green light to one language and red to another.
“When you have to do that all the time, you get really good at inhibiting the words you don’t need.”
If the brain is constantly exercised in this way, it doesn’t have to work as hard to perform tasks.
The study, published online by the journal Brain and Language, was one of the first to use functional magnetic resonance imaging (fMRI) to test co-activation and inhibition in bilinguals.
Co-activation during speaking, a concept Dr Marian pioneered in 1999, means that fluent bilinguals have both languages “active” at the same time, whether they are consciously using them or not.
Inhibitory control involves selecting the correct language in the face of a competing other language.
Earlier in her career, Dr Marian recorded eye movements to track co-activation and inhibition.
She found that when bilinguals heard words in one language, such as “marker” in English, they often made eye movements to objects whose names sounded similar in another language they knew, such as “marka” which means stamp in Russian.
In her recent study, volunteers were asked to perform language comprehension tasks.
On hearing a word, the participants were shown pictures of four objects.
For example, after hearing the word “cloud” they would be shown four pictures, including a picture of a cloud and a picture of a similar-sounding word, such as a “clown.”
The participants needed to recognise the correct word and ignore the similar-sounding, competing word.
Dr Marian found that bilingual speakers were better at filtering out the competing words because their brains are used to controlling two languages and inhibiting the irrelevant words.
The brain scans additionally showed that “monolinguals had more activation in the inhibitory control regions than bilinguals; they had to work much harder to perform the task.”
By studying the brains of participants using MRI imaging, she found that blood flows to certain areas as each of the volunteers performed a cognitive task.
The more oxygen or blood flow to the region, the harder that part of the brain is working.
“Inhibitory control is a hallmark of cognition,” said Dr Marian.
“Whether we’re driving or performing surgery, it’s important to focus on what really matters and ignore what doesn’t.”
Dr Marian said the fact that bilinguals are constantly practicing inhibitory control could also help explain why bilingualism appears to offer a protective advantage against Alzheimer’s and dementia.
She added: “That’s the exciting part. Using another language provides the brain built-in exercise.
“You don’t have to go out of your way to do a puzzle because the brain is already constantly juggling two languages. “ - Daily Mail