The bilingual brain

KATE BARBER talks with neuroscience educator NATHAN WALLIS about the profound impact that learning a second language has on the development of the brain.

Of all the things our brain does, language is the most complex, according to neuroscientist Nathan Wallis. The brain requires cognitive structures to support the acquisition of language, and “the more richly diverse the language, the more complex these structures need to be,” he explains.

It follows then, that growing up in a bilingual environment or having regular exposure to a second language leads to more complex cognitive development. That is, the benefits extend far beyond knowing two languages: learning a second language makes the brain itself more intelligent.

Nathan explains that there are measurable changes to the structure of the brain if a child is exposed to two languages before the age of seven. While there are, of course, advantages in learning a second language after this age, “the corpus callosum is measurably thicker if two languages are present before seven.

“It’s difficult to leap from brain structure to the exact functions of the brain,” he continues. “It’s a new and developing science, and the brain is more complex than that. But the corpus callosum integrates left and right hemispheres and this is associated with emotional regulation as well as higher cognitive function.”

In terms of cognitive function, “as soon as you have two languages, you actually have three,” he says, because you have what’s called metalanguage, which is the capacity to compare these languages in terms of the rules they follow – whether the adjective precedes the noun (as in English) or follows it (as in Spanish), or whether the language contains gendered pronouns (he/she) or only gender neutral ones.

Being able to compare the languages also involves recognising the different world views or ways of thinking that they open up. Nathan compares te reo Māori and English by way of example: whereas English is a language for technology, he says, te reo is one for spirituality, with many concepts that cannot be directly translated into English, like mana and mauri.

Metalanguage and metacognition are associated with higher intelligence, says Nathan. Once we have metalanguage, it becomes easier to pick up other languages. “The big leap is from one to two.”

So when is the time to take this big leap? In terms of reaping the benefits of learning a second language, “the earlier the better,” he says. “We have this window of opportunity when we are young to pick up a first language, and the same applies with a second.”

When it comes to school, the focus at primary is on developing children’s English language skills; generally speaking, it is not until secondary school that students are offered the chance to learn a second language. That our children should consolidate one language before we introduce a second is an “old-fashioned idea”, he says.

But is there any shadow of truth in thinking that exposing a baby/child to a second language will hinder their progress with English? As Nathan explains, “growing up bilingual is, overall, associated with enhanced language acquisition in both languages, but could mean a child’s first language takes slighter longer to emerge as the child deals with the complexity of two languages. At three years of age they often mix the languages together, and may even create their own language, based on the two they have along with a dose of imagination. We now understand this to be a sign of complexity, not confusion.

“Generally, by five years of age, a child understands the first language better than a child exposed only to that first language.”

As astounding and exciting as this all sounds, how can we support our children to learn a second language? As products of an education system that focuses almost exclusively on English, many of us speak only one language: we talk, read and sing with our babies and children in English alone.

Despite this obstacle, all is not lost. As Nathan says, it takes only 60 words to cover all the sounds unique to a language. So, by singing two waiata or reading two nursery rhymes in te reo each day, you expose your child to the unique sounds of that particular language thereby wiring up their brains to these sounds.

Whichever second language you choose to introduce to your child, it’s important to be committed and to speak the language with enthusiasm, he says. Using correct pronunciation is also important and exposing your child to a fluent speaker of the language is incredibly valuable in terms of reinforcing these connections.

Contrary to concerns that speaking to our babies and young children in a second language will confuse them, Nathan says that we actually want there to be some confusion. In the early years the brain is working out what sort of brain it needs to be for life. Through nurturing, responsive interactions that are richly diverse in language, the brain will grow; and through confusion it will develop greater structural complexity.

Kids who grow up exposed to and speaking only English “miss out on so much,” he says, in terms of the worlds that different languages open up, and in terms of the complexity of their brains.

In his presentations across the country and overseas, neuroscience presenter and director of X-Factor Education, Nathan Wallis explains that in the last 20 years there has been a proliferation of information about the brain and how it grows. He talks about the importance of our interactions with babies and young children in the first 1000 days as their brains ‘wire up’ for life.

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