New studies are shedding light on how multiple language exposure impacts a child's developing brain.
The UAE is a land of many tongues. At least 10 languages are in everyday use by various sections of the population, and many others can be found in pockets.
A question then arises: how does this polyglot experience affect the children growing up here? Does it rub off on the way their brains develop, even in the womb?
A number of recent studies, both in the UAE and in the West, are shedding light on the matter.
Last year, researchers at the University of Washington used measures of electrical brain responses to compare infants whose parents spoke several languages to those exposed to just one.
They found that monolingual infants differentiated between phonetic sounds from different languages as early as six months. But by 10 to 12 months, they could recognise only sounds from the language they usually heard.
In contrast, bilingual infants did not begin differentiating between the phonetic sounds of both their languages until 10 to 12 months. That, says one UAE expert, could be the result of a profound change in how the babies' brains work.
"In the first six months, children are typically babbling and exploring what kind of sounds they can make," said Anne Eichberger, a speech pathologist at the Child Learning and Enrichment Medical Centre in Dubai.
"A normally developing child is usually producing at least five words by 12 months - usually the words they are exposed to the most."
Researchers from the University of British Columbia have found that newborns prefer languages, such as Cantonese, Mandarin and Tagalog, that are rhythmically similar to what they heard in the womb.
Infants whose mothers spoke both English and Chinese regularly during pregnancy were tested for their preference between Tagalog and English, and the results were compared to those of infants coming from English monolingual and Tagalog bilingual (Tagalog and English) backgrounds.
The newborns were given a "high-amplitude sucking preference" test. Newborns sucked on a rubber nipple and were presented with 10 minutes of speech, alternating each minute between the two languages. To assess preference, the number of high-amplitude sucks produced during Tagalog minutes versus English minutes was compared.
The study found that Chinese bilingual infants were more interested in Tagalog than their English monolingual counterparts were, while all newborns showed the highest preference for their own languages.
Whatever changes there are, it appears they start early; neurons in the brain start absorbing information at birth, or even before.
"The more you provide stimulus to the brain, the more it will begin to form connections," says Shola Faniran, a developmental paediatrician at the Child Early Intervention Medical Centre in Dubai. "In utero, babies can distinguish between the mother and father's voice, and are more likely to respond to the mother's voice.
"They do not understand that language itself, but they recognise the intonation, sound and calibre of the voice."
A study in 2010 by the University of Montreal and Sainte-Justine University Hospital Research Centre in Montreal found just this. Using electrodes, researchers monitored infants' brain activity within 24 hours of birth. They found that the parts responsible for language processing in the left hemisphere of the brain reacted only to the mother's voice, and not to the voice of a female stranger. It was the first study to be conducted on infants that young.
These findings back up the prevailing wisdom: that the earlier a second language is introduced, the better the child will pick it up.
The question is: why?
Dr Anatoliy Kharkhurin, an associate professor of psychology at the American University of Sharjah, has been studying bilingualism for nearly 10 years, and is a proponent of what is known as the "critical period hypothesis", which suggests that the brain is "open" to easier multilingualism up to a certain age, after which is becomes much harder to take on a second language.
"This hypothesis is related to brain flexibility, how easily you can absorb these tiny bits of information, because language is a very complex system," he says.
What remains unclear is when that critical period is - how old children are when their brains start to shut out unfamiliar languages.
On this experts disagree, with estimates ranging from seven to 16 years. The acclaimed linguist and neurologist Eric Heinz Lenneberg, for example, hypothesised that second-language teaching must start before the age of 12.
After that, according to Lenneberg's theory, people tend to speak with an accent and make mistakes.
"That's because the brain matures, becomes less flexible and the individual cannot acquire the necessary skills to have perfect language command," Dr Kharkhurin said.
In the UAE, there are many cases where the father and mother speak different languages, and a third, primarily English, is taught in schools. In many Lebanese families in particular, French and Arabic are used at home and English is taught at school.
That mishmash might result in slight language delay - but no cause for concern. "Children may go through a silent period when they're being exposed to both languages," said Ms Eichberger. "It's normal for a few months as they're digesting everything and don't feel that comfortable having a lot of expressive communication."
There is a question, too, of whether bilingualism tends to help or hinder children's general development. Some say it hinders, pointing to studies on under-fives that have found lower cognitive performance on tasks such as problem-solving and multitasking among bilingual children.
"Before the age of five, children have to master not one but two highly sophisticated language systems," Dr Kharkhurin said. "Therefore, they're slow in cognitive development."
After that, though, bilingual children catch and pass their monolingual peers, outperforming them on "pretty much all cognitive tests", he said.
"So parents who see their children showing delays in their cognitive development … should have a little bit more patience and wait until both languages have developed. After that, they'll see progress."
Other studies have found that multilingual individuals are more creative and better at problem-solving - possibly because of different patterns of brain activity.
In monolinguals, it is thought that language processing takes place in the brain's left hemisphere. Bilinguals, by contrast, use both sides.
"Since the right hemisphere is involved, it becomes more active in the bilingual brain," Dr Kharkhurin said. "The right hemisphere is responsible for non-verbal, artistic and creative [abilities]. For this reason, it is possible that because the right hemisphere is more active, people tend to be more creative."
Bilinguals seem better at focusing on particular nuggets of information, and disregarding others - perhaps because they routinely have to clear out the clutter of other languages to use just one at a time.
"The same cognitive mechanism is involved in creative thinking," Dr Kharkhurin said. "In order to come up with a creative idea, you need to focus your attention on this idea and ignore others."
And their adeptness at code-switching - the practice, familiar to anyone in the UAE, of switching between different languages within a single sentence - could also boost creativity, inshallah.
"There are a few reasons to code-switch. Sometime it's because you can't find the word in the target language, or you want to be more efficient in expressing what you want," Dr Kharkhurin said. "This … also contributes to their cognitive advantages, such as creativity and problem-solving."
It is this selective attention that allows bilinguals to focus on certain areas of a task and ignore others. Further studies need to be conducted on how bilingualism impacts the brain's other functions, particularly creativity, Dr Kharkhurin said.
And that is what he hopes to achieve in his efforts to introduce multilingual learning to schools, where students will not only take subjects in two languages, but do so using creative methods.
"The relationship between bilingualism and creativity was abandoned for 30 years because of its [complexity]," he said. "Through these findings we can reach into the untapped potential of bilingual children."