Mapping the Bilingual Brain

I came across an interesting article today and I decided to translate it into English. Here is a link to the original article for those interested. I hope this wasn’t already a translation from English, and I don’t think it was, because then I just wasted two hours this morning. Either way, enjoy!!

Language is not something that exists outside of us, it “lives” in the brain. Learning a single language or learning two simultaneously will lead to a difference in the neural network in monolingual and bilingual people, but how does this difference influence us? Do polyglots have superior communicative abilities? Are bilingual babies smarter? Does learning Spanish and Catalan have the same effect during development as does learning English and Japanese?

Many groups of scientists are studying the language acquisition process and how languages are organized in the brain. One of the most prestigious and prolific is the BRAINGLOT group, comprised of six groups and over 200 researchers. It deals with a project from Spain that, since its conception four years ago, has not ceased publishing interesting results regarding different aspects of bilingualism based in the disciplines of functional neuropsychology and linguistics.

“Spain is the ideal place to carry out this type of research for different reasons. Few countries, if any, have our peculiarities. We have individuals who speak languages that are very similar, like Spanish and Catalan, and others that are disparate like Basque and Spanish. Moreover, we also have monolinguals. There is a certain homogeneity about these individuals in terms of social status and education, and the differences that separate them are small,” says Nuria Sebastian-Galles, Ph.D in psychology, head researcher of the Percepción y Adquisición del Discurso [Speech Perception and Acquisition] group at the University Pompeu Fabra in Barcelona and coordinator of the BRAINGLOT project.

Counted among its goals are discovering the neural basis of language processing in bilinguals, finding out the positive and negative differences a second language creates in the brain, and detecting how much overlap there is in the neural networks when switching from linguistic and non-linguistic tasks. To achieve these objectives, Cesar Avila, professor of basic psychology at the University Jaume I and his group, are working in the functional neuroimaging lab to take a “portrait” of the bilingual brain.

Cognitive Flexibility

Differences in the frontal inferior gyrus in a monolingual brain (red) and a bilingual brain (blue) | BRAINGLOT

“Bilingual people use more of their brain when carrying out a linguistic task, generally on the left side of brain (the side associated with language) and a bit on the right side. The process is less efficient but not less effective, rather, bilinguals perform the task as well as their monolingual counterparts, but to do so they need to employ more of their brain. This could be thought of as a sort of minute slowing when the brain is asked to perform these language tasks. However, the positive is that early bilinguals have highly-trained non-linguistic abilities thanks to their constant switching of languages; concretely, the executive functions, that serve to adapt to the changes of varying tasks. It can be said that in these tasks, bilinguals are better. We provide the visual basis for why they are more effective at this; we have seen that is because they use other parts of the brain that monolinguals do not,” adds Avila.

Ellen Bialystok and Michelle Martin, two experts in bilingualism, explain in an article published in 2004 in the magazine Developmental Science, that “early bilingualism modifies and enhances the development of attention control in children while having little impact on how representations are analyzed.” But, another article published two years ago in Asociación para la Ciencia Psicológica [Association for Psychological Science] sustains that “those who speak two languages have lower competence in formal language.”

As Albert Costa, coordinator of the Investigación en Producción del Habla y Bilingüismo [Research on Speech Production and Bilingualism] group at the University Pompeu Fabra, points out “they are two sides of the same coin. When it’s time to produce languages it seems that bilinguals are slower and exhibit higher frequencies of having difficulty finding the desired word, what we call having the word on the tip of your tongue. Furthermore, they have a smaller vocabulary, although if you take into account both languages the raw number of words they know is higher than that of a monolingual. But this is logical, it’s like someone who plays only tennis and someone who plays tennis and racquetball; the first will be better at tennis but the second will be versed in the two sports.” he explains.

The divergence in cognitive flexibility is not “a huge difference, if it were, the world would be dominated by bilinguals. Regarding managing language, this slowness in finding the right word is on the scale of milliseconds; while the person speaks he or she is not aware of the other languages pedantically vying for attention and that the brain is constantly choosing the language to speak with.” adds Sebastian-Galles.

Language in Babies and Seniors

What indeed is apparent is that the advantages of being bilingual are most noticeable in small children and senior citizens. “The prefrontal area is the part of the brain that stops developing later in life, it does so during late adolescence and is of the first areas to decline when we turn 30-40 years old. Since bilinguals have this area better trained, this helps to accelerate development and it seems to prevent or slow the appearance of symptoms of deterioration,” details Sebastian-Galles. Though, Costa adds, “we must be careful relating to dementia since there are few studies focused on that.

It appears that the mental exercise of learning and using two languages contributes to what is called cognitive reserve, that’s to say, bilinguals with the same amount of brain damage caused by dementia or Alzheimer’s present with fewer symptoms than their monolingual counterparts. Ideally there would be more data on this. In Spain it would be possible to do a serious epidemiological study, but since bilingualism is a politically sensitive topic, there is no interest in carrying one out.”

Another branch of research is seeking to learn more about the differences created at very young ages. “We do not work much with infants, but there are studies on the subject. It is known that in the first months babies cannot distinguish between two languages, but at four months babies can differentiate Spanish from Catalan. Also, at eight months, bilingual babies can note the differences between Spanish and French, for example, simply by watching two people speak, without hearing the words, whereas a monolingual baby is unable to do so,” affirms Sebastian-Galles.

In her work, they have also shown, via functional MRI, that even though one learns two languages from birth, one language will always be dominant, and that will be the one that the baby is most exposed to (usually the mother’s language). “This can only be seen with very fine techniques because there are very small differences, so much so that the person does not realize that he or she handles one language better than the other,” says Sebastian-Galles.

Learning a Second Language

Besides coming to understand the benefits of bilingualism in the executive functions, another branch of study of the BRAINGLOT project is to learn why is it so hard to learn a second language beyond a certain age. “Our work is to investigate what things that are different from one language to the next are the ones that will be easier or harder to learn,” explains Itziar Laka, professor of linguistics at the University of the Basque Country and principle researcher of Elebilab, a participating group in the project.

Laka analyzes people’s brain signals when they hear a mistake in a language (like a syntactic violation) and the way the brain codes this. “There is something that the people do not realize: they believe that language is something cultural but this not the case, it is a cognitive function. If the second language is very different, the brain pattern will be different in a bilingual person than in a native speaker. But we also study which aspects of the language are represented in the same way in the brains of the two people,” she adds.

Laka insists that the information mined while studying the brain of a bilingual is much richer than the information of a monolingual speaker. “The whole picture allows us to better understand the nature of language,” she affirms. She evaluates twenty-somethings that learned Basque when they were four or five years old. “We thought that there would be no difference between these subjects and native speakers, but there were. At four years old, the first language has already taken a priority space in the brain, and the second language has to fight for its own place.”

Though it is also known that because using the first language is easier, the brain tissue involved in its use is less. In fact, various studies show that there is a difference in the density of the white matter between bilinguals and monolinguals. “With more myelin the faster the brain can process. The differences are not solely functional but also structural. The important take-away here is the determination that external learning shapes the cerebral morphology,” adds Costa.

The Basque group also analyzes the effect of ergativity in language. “[B]asque, like the Mayan languages, Georgian and Tibetan, are ergative-absolutive languages and they have a way of marking subjects and objects that is different than the nominative languages, the family of languages the Romance languages belong to. This has been considered a psychological division. We also look at aspects like verbal agreement, which in Spanish is only with the subject, whereas in Basque it is with the subject, object and dative. There we see that when you have agreement in your native language, you can use it as a resource for the second language.”

Individual Learning

Definitively, the aim of these researchers is to create a map of what is different in the language and, when it’s not native, how this is represented in the brain. “We have tried to complete the map for four- and five-year olds to know how they place the second language in their brains when it is learned at this age. We hope to have a solid and serious empirical basis to argue which things are difficult and which are easy when learning a language,” explains Laka.

“While with our native tongues we are all equally as good, there are only educational differences; in second languages not everybody is equal. There is evidence that suggests some ways of learning a language are better for some people than for others. Perhaps in the future we will be able to predict, depending on the type of person you are, the best way to learn for each person,” muses Laka.

A long-term goal is to gain knowledge on how to achieve maximum efficiency when learning a second language. “But this will only be possible when we know much more on the topic,” explains Laka who also points out the lack of resources for next year. “The project was born with the political commitment that the resources we were to have would not go dry after five years, but rather there would be continuity. But this has changed. It’s true that the economic situation is at fault, but it is a shame that in an ideal country to study bilingualism, we can’t. This is not a problem stemming from human resources, it’s a problem of stability and infrastructure to do science.”

[all images from

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