A medical expedition into the bilingual brain

Live French is with Franck Scola, a doctor dedicated to expatriate families, specialising in cross-cultural psychiatry.

Why should the medical profession focus on bilingualism?
Each language is a code that works as a tool for language. Language is a physical, mental and social activity, since it involves the body, brain functions and life within a group.
Medicine brings together sciences that consider man in his physical, mental and social dimensions.
When several languages coexist in an individual, they are part of his linguistic, cognitive, emotional and identity functions. Thus, among the many sciences which study bilingualism (sociology, sociolinguistics, psycholinguistics, educational sciences…), medical disciplines (neurology, developmental psychology, transcultural clinical…) are an integral and irreplaceable component.

How do the developmental stages of the bilingual child differ from those of the monolingual child?
It would be inaccurate to say so. On the one hand because the population of bilingual children is not homogeneous but composed of different types of bilingualism; on the other hand, because the simultaneous bilingual child (two languages of exposure from the beginning of life) develops his or her oral language in a way that is closer to a monolingual than to a consecutive bilingual (one L1 language then another, L2 later before the age of six) or to a late bilingual (L2 after six years).
However, in the simultaneous bilingual, there is a delayed onset of oral language (false language delay in the simultaneous bilingual) followed by code-mixing (language mixing) and then interference as long as both languages are acquired “in bulk”, and until the two language stocks separate in the 5th year.
In consecutive bilingualism, the child is exposed to an unknown language that will become his or her second language. He is first allophone (without competence in the environmental language), then becomes passive bilingual (able to understand this language but not to speak it), then active bilingual as soon as oral productions appear in both languages. The stages observed will typically be a selective mutism (oral expression rare, or even non-existent, in a foreign language environment) followed by a stage of interlanguage (oral productions which are incomprehensible because they do not correspond to lexical elements of the target language), then a stage of interference and code switching (alternating languages) during which the languages are mixed. Finally, the child will have enough competence in each language to use them usefully in the appropriate context.
In the case of the late bilingual, this is not language development through several languages. It is foreign language learning.

Are there benefits of bilingualism on intellectual performance?
Yes, there are, but not for all bilingual individuals. When this is the case, we speak of additive bilingualism.
These benefits can then be found at various levels:
– Linguistic (in the mastery of languages already acquired and in the acquisition of new ones),
– Language skills (oral and written),
– Auditory and vocal (heightened ability to recognise and imitate phonemes)
– Cognitive (on certain reasoning skills, notably the sense of the relative)
– Memory (memorization skills)
– Cultural
– Professional opportunities, in terms of career enhancement and networking

It is therefore in the active and additive bilingual person that these additional skills are indirectly beneficial to academic skills and offer advantages in terms of future socio-professional success.
However, these gains brought by bilingualism do not benefit everyone, because sometimes, on the contrary, bilingualism has disadvantages and involves some risks.

Among the risks associated with early bilingualism, which are the highest?

Among the risks associated with early bilingualism, which are the highest?
All those linked to conditions that are unfavourable to a fulfilled bilingual childhood, where monolingualism would have been more beneficial. On one hand, in the case of limited bilingualism, certain language behaviours show a regression. This is the case with double semi-linguisms (inability to function cognitively in languages) and subtractive bilingualism (where the acquisition of an L2 is at the expense of the L1). In subtractive bilingualism, the level in each of the languages is lower than that of a monolingual of either language. The consequences of these language deficiencies then have repercussions on oral and written language, and then on access to knowledge.
We can also cite cases of disturbances in the identity construction process and in the case of the socialisation of bilingual children and adolescents living in a predominantly monolingual environment, in whom bilingualism is experienced as a burden rather than an opportunity. This is all the more the case when the language spoken is rare or less prestigious in the host country. The identity strategy aimed at integrating into the group and getting out of this painful situation will consist sometimes in erasing the language traits associated with the language of origin (accent, rhythm, etc.), and sometimes in perfecting the majority language. A third possibility is the attrition of the original language, i.e. the abandonment of its use until the ability to speak and even understand it is lost.
Language development delays may also be observed, although not all of them are real and even less pathological in bilingual contexts; also to be noted are states of isolation, selective mutism (no verbal production outside the home) and suffering in the school environment.
All of these signs, which are likely to worry families or educational teams, are the reasons why parents come to me for consultation about their child. In addition to these, there is one last one, less related to the child and more to his environment, when his language atypia is misinterpreted by his parents, his teachers, a doctor or a speech therapist. Indeed, the developmental specificities of bilingual children run the risk of being unduly blamed on pathological disorders.

Does exposure to foreign languages at an early age guarantee perfect and lasting bilingualism?

Does exposure to foreign languages at an early age guarantee perfect and lasting bilingualism?
This belief is as enduring as the inhuman assertion that a child’s brain is a sponge. Rather than through a process of absorption, acquisition of knowledge and skills by a human brain functions more like a processor, selecting and sorting incoming information, then processing and storing or discarding in different ways according to each individual.
The theoretical notions of an “optimum age” and a “critical period” put forward by several teams of neurologists in the 1950s assumed a superiority of linguistic acquisition in the smallest children. However, these demonstrations were called into question in the 1970s.
It is true that before the age of 6 (early bilingualism), languages are acquired without learning, and the language function is then acquired from both languages. In each type of early bilingualism, neither simultaneous bilingualism nor consecutive bilingualism demonstrates better acquisition in either language. Nor do they guarantee lasting mastery.
In the course of a child’s life, factors that could lead to a partial or total loss of mastery of that language are an interruption or deterioration in the quality of immersion in a language and circumstances reducing the usefulness or degrading the prestige of that language.
In internationally adopted children, attrition (total loss) of the native language is frequent both through the cessation of exposure and verbal solicitations, of responses to a need, and often because of a less comforting emotional etiquette compared to that of the host parents.

What actions are likely to favour or hinder language acquisition in the child of a mixed couple?
It is essential that such a child benefits from regular, prolonged and good quality immersion in the language of each parent. The quantity is important but also the quality (syntax, grammar and vocabulary). Each language must represent a need, involve trait affiliation (bonding) and be accepted and valued. However, the proportion of exposure to each of the two languages will inevitably be inequitable, particularly depending on whether the child is from a mixed couple living in the country of one of the spouses or in a third country. Moreover, since the unspoken is of paramount importance in parental transmission, many implicit factors will determine the difficulty or failure of the “natural” transmission of bilingualism to a child.
Eleven success factors and eleven failure factors were identified by Susan Mahlstedt. This researcher based her hypothesis on the observation that in some families where two languages live together, some children develop a near-balanced bilingualism while others have a dominance of one language, and finally a third category struggles to acquire one of them.

Are dys disorders more frequent in bilingual children?
It is rather that doctors, psychologists or speech therapists who are not trained to interpret the typical atypicalities of bilingual children, whether they are language related or language learning related, tend to conclude all too hastily that these atypicalities represent early dys disorders (dyslexia, dyspraxia, dyscalculia…) in these children. My colleagues frequently ask me to clarify or confirm a doubt about dysphagia, dyslexia, dysorthographia or dyscalculia.
It should be remembered that this is how some specific disturbances of oral or written language associated with disorders of certain brain functions which actually facilitate the acquisition and use of language (memory, attention, concentration, temporo-spatial structuring, logical and abstract thought, ability to generalise…) are often classified. But to say they are specific means they are not the result of an illness, an accident, or even to a life context such as bilinguality.
These disorders can indeed occur in a bilingual child, as they would have occurred identically in the same child if he or she were monolingual.
Moreover, depending on the type of bilingualism, the symptoms of the disorder will not manifest themselves in the same way in one language or the other.
For example, in the case of a dyslexic simultaneous bilingual, slowness and a tendency to tire in the reading effort will theoretically be experienced just as much in both languages. However, in a dyslexic consecutive bilingual, these symptoms will be felt more in the L2 than in the L1, due to the additional work involved in translating. And this will be even more observed in the late bilingual.
Thus, we can consider that in the simultaneous bilingual, the effect of a dys disorder is the same as in a monolingual because it has the same characteristics in all the codes used for language. In this, it differs from the other categories of bilingualism.


Franck Scola M.D., PhD
Doctor for expatriates
Coordinator of the Be-Rise scientific committee