Continued from page 1

They found a dramatic shift in attention: When the speaker used English, the 4-month-olds gazed mostly into her eyes. The 6-month-olds spent equal amounts of time looking at the eyes and the mouth. The 8- and 10-month-olds studied mostly the mouth.

At 12 months, attention started shifting back toward the speaker’s eyes.

It makes sense that at 6 months, babies begin observing lip movement, Lewkowicz says, because that’s about the time babies’ brains gain the ability to control their attention rather than automatically look toward noise.

But what happened when these babies accustomed to English heard Spanish? The 12-month-olds studied the mouth longer, just like younger babies. They needed the extra information to decipher the unfamiliar sounds.

That fits with research into bilingualism that shows babies’ brains fine-tune themselves to start distinguishing the sounds of their native language over other languages in the first year of life. That’s one reason it’s easier for babies to become bilingual than older children or adults.

But the continued lip-reading shows the 1-year-olds clearly still “are primed for learning,” McMurray says.

Babies are so hard to study that this is “a fairly heroic data set,” says Duke University cognitive neuroscientist Greg Appelbaum, who found the research so compelling that he wants to know more.

Are the babies who start to shift their gaze back to the eyes a bit earlier better learners, or impatient to their own detriment? What happens with a foreign language after 12 months?

Lewkowicz is continuing his studies of typically developing babies. He theorizes that there may be different patterns in children at risk of autism, something autism experts caution would be hard to prove.


EDITOR’S NOTE _ Lauran Neergaard covers health and medical issues for The Associated Press in Washington.