Washington | Babies raised in bilingual households show brain activity associated with executive functioning as early as 11 months of age, according to a new study. Many brain studies have shown that bilingual adults have more activity in areas associated with executive function, a set of mental abilities that includes problem-solving, shifting attention and other desirable cognitive traits.
New findings show that this bilingualism-related difference in brain activity is evident as early as 11 months of age, just as babies are on the verge of producing their first words. Our results suggest that before they even start talking, babies raised in bilingual households are getting practice at tasks related to executive function, said Naja Ferjan Ramirez from University of Washington.
This suggests that bilingualism shapes not only language development, but also cognitive development more generally, Ramirez said. The study gives evidence that the brains of babies from bilingual families remain more open to learning new language sounds, compared with babies from monolingual families.
Monolingual babies show a narrowing in their perception of sounds at about 11 months of age – they no longer discriminate foreign-language sounds they successfully discriminated at 6 months of age, said Patricia Kuhl from University of Washington. But babies raised listening to two languages seem to stay ‘open’ to the sounds of novel languages longer than their monolingual peers, which is a good and highly adaptive thing for their brains to do, Kuhl said.
Researchers used magnetoencephalography (MEG), which measures magnetic changes given off by active nerve cells.
Unlike other brain-imaging methods, MEG can precisely pinpoint both the timing and location of activity in the brain. In the experiment, sixteen 11-month-old babies – eight from English-only households and eight from Spanish-English households, and an even mix of demographic factors such as the family’s socioeconomic status – sat in a highchair beneath the helmet-like MEG scanner.
The babies listened to an 18-minute stream of speech sounds. The stream included sounds specific to English or Spanish, and sounds shared by the two languages. Researchers compared monolingual and bilingual babies’ brain responses to the language sounds.
The most obvious difference they saw was in two brain regions associated with executive function, the prefrontal cortex and orbitofrontal cortex. In these regions, the Spanish-English bilingual babies had stronger brain responses to speech sounds, compared with English-only babies, researchers said.
The 11-month-old baby brain is learning whatever language or languages are present in the environment and is equally capable of learning two languages as it is of learning one language, said Ramirez.
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