Bilingual babies keep ability to discern languages from visual cues

I've always wondered about this...

Bilingual babies keep ability to discern
languages from visual cues

Last Updated: Thursday, May 24, 2007 2:22 PM ET

CBC News

Babies as young as four months old can tell whether a speaker has
switched languages from visual cues alone, but only those who grow up in a
bilingual home seem to hang on to the ability, researchers in British Columbia
have found.
In Friday's issue of the journal Science, Whitney Weikum, a
doctoral student in neuroscience at the University of British Columbia, and her
colleagues report the results of their tests on infants who were shown video
clips of bilingual speakers.
The caregivers wore darkened glasses to prevent
influencing the babies, who were watching silent video clips of bilingual
speakers.

The study is the first to show young babies are prepared to tell
languages apart using only visual information, Weikum said.

The researchers tested infants at four, six and eight months of age
from English-only homes and six and eight-month-olds from bilingual English and
French homes. Each group was shown silent video clips of bilingual speakers, who
recited sentences first in one language and then switched to the other.

At four and six months, babies paid closer attention and watched the
video for longer when the speakers switched languages, which suggests the
infants were able to discern the change from visual information alone.

While six-month-olds from monolingual and bilingual environments could
tell languages apart visually, by eight months of age, only babies from
bilingual homes who were familiar with both languages continued to be able to do
so, the researchers found.

"This suggests
that by eight months, only babies learning more than one language need to
maintain this ability," Weikum said.

"Babies who only hear and see one language
don't need this ability, and their sensitivity to visual language information
from other languages declines."