Science of Language

Too late for a second language?

Learning a language is harder as we age because brain cells become more specialised. “As an infant you start with masses and masses of connections and these are refined as you develop, until you are just left with what you need,” says Professor Sophie Scott from the Institute of Cognitive Neuroscience in London. “When you are an adult your perceptual system is attuned to the language you have learnt.” For example, speakers of Chinese, a tonal language where the tone or pitch of a word can alter its meaning, are thought to develop greater activity in the right cerebral cortex of the brain when listening to their own language compared with non-tonal language speakers. This area is thought to process the intonation of words, which is so crucial in tonal languages.

But adults shouldn’t be discouraged. Even after the critical period, it is still possible to become fluent in a new language. “Because your first language is in place, the core elements of language such as syntax can be transferred from your first to your second language,” says Mattys. “On the other hand, since you don’t start with a blank slate, it can interfere with other levels of language learning.”

Bilingual brain

Too many words? The brains of bilingual children are able to distinguish between the two languages.

Yet the brain is remarkable in being able to distinguish between two languages. Bilingual children may take slightly longer to utter their first word but they quickly learn when to speak which language. A recent study published in Psychological Science by researchers at the University of Oregon suggests that when an adult first learns a second language, the brain actively inhibits the first one. The researchers found that after learning to speak Spanish, native English speakers found it more difficult to recall English words. So if you travel abroad to immerse yourself in another language, you may end up finding it hard to speak your native tongue when your return.

As you become more proficient in your second language, scientists believe that the brain becomes better at preventing interference with your native tongue. Evidence from functional magnetic resonance imaging (MRI) studies supports this idea. “It seems that the words for language one and language two are stored in different areas of the brain, “says Mattys. “The more proficient you are, and the earlier you have been exposed to the second language, then the more separate these areas are.”