Friday, May 25, 2007

Babies Can Tell When You Switch Languages By Watching Your Face

Medical News Today reports:

Researchers at the University of British Columbia (UBC) in Canada have shown that at four months babies can tell when a person switches to a different language just by watching their face.
Whitney Weikum and her colleagues published their findings in the journal Science.

They found that babies can tell when people switch to speaking a different language from the change in rhythm of their mouth and face movements.

As they get older, babies who are not exposed to more than one language lose this ability, but babies growing up in a bilingual environment retain it.

Weikum, who is a neuroscience doctoral student working with Canada Research Chair and Psychology Professor Janet Werker, said:

"We already know that babies can tell languages apart using auditory cues. But this is the first study to show that young babies are prepared to tell languages apart using only visual information."

She and her team explored whether babies use vision to distinguish between people speaking familiar and unfamiliar languages.

They tested three groups of babies aged 4, 6 and 8 months from homes where only English was spoken, and they also tested two groups of babies aged 6 and 8 months from bilingual homes where French and English were spoken.

They showed each age group of babies videos of three people speaking sentences in English or French who then switched to the other language.

The babies attention was monitored by a computer that measured their looking time. When the looking time started to fall off, the computer switched the video to show the speaker talking the other language.

They found that the bilingual French-English and monolingual English 6 month old babies could tell when the speaker switched to a different language because they watched with renewed interest; their looking time went up again.

However, the 8 month old babies from homes where only English was spoken did not show renewed interest when the speaker switched languages. Only the babies from the bilingual French-English homes did so.

Weikum and colleagues suggest that:

"By eight months, only babies learning more than one language need to maintain this ability. Babies who only hear and see one language don't need this ability, and their sensitivity to visual language information from other languages declines."

They said the study shows how sensitive infants' language development is to their learning environment, and only if they are exposed to more than one language do they retain the ability to tell them apart using vision alone. The study also shows that language recognition is multimodal; while other studies show it relies on aural cues, this one shows that visual cues are used as well.

The researchers point out that the study does not prove that visual cues help babies learn languages, it only shows they use them to tell them apart. Parents concerned their child is missing out if only one language is spoken at home should not be concerned, but should continue talking to them and make conversation fun and engaging, they said.

The research team now want to find out which visual cues bilingual babies use to differentiate languages.

"Visual Language Discrimination in Infancy."
Whitney M. Weikum, Athena Vouloumanos, Jordi Navarra, Salvador Soto-Faraco, Núria Sebastián-Gallés, and Janet F. Werker.
Science 25 May 2007, Vol. 316. no. 5828, p. 1159
DOI: 10.1126/science.1137686