Each language uses a unique set of sounds. Scientists now know babies are born with the ability to distinguish all of them, but that ability starts weakening by the first birthday, even before they start talking.
Mastering your dominant language gets in the way of learning a second, less familiar one, Kuhl’s research suggests. The brain tunes out sounds that don’t fit.
“You’re building a brain architecture that’s a perfect fit for Japanese or English or French,’’ whatever is native, Kuhl explained - or, if you’re lucky, a brain with two sets of neural circuits dedicated to two languages.
It’s remarkable that babies being raised bilingual - by simply speaking to them in two languages - can learn both in the time it takes most babies to learn one. On average, monolingual and bilingual babies start talking around age 1 and can say about 50 words by 18 months.
Italian researchers wondered why there wasn’t a delay, and reported this month in the journal Science that being bilingual seems to make the brain more flexible.
The researchers tested 44 12-month-olds to see how they recognized three-syllable patterns. Sure enough, gaze-tracking showed the bilingual babies learned two kinds of patterns at the same time - like lo-ba-lo or lo-lo-ba - while the one-language babies learned only one, concluded Agnes Melinda Kovacs of Italy’s International School for Advanced Studies.
