Babies don't learn to talk just from hearing sounds. New research suggests they're lip-readers, too.
It happens during that stage when a baby's babbling gradually changes from gibberish into syllables and eventually into that first "mama" or "dada."
Florida scientists discovered that starting around age 6 months, babies begin shifting from the intent eye gaze of early infancy to studying mouths when people talk to them.
"The baby in order to imitate you has to figure out how to shape their lips to make that particular sound they're hearing," said developmental psychologist David Lewkowicz of Florida Atlantic University, who led the study of nearly 180 babies published Monday in Proceedings of the National Academy of Sciences.
Apparently it doesn't take them too long to absorb the movements that match basic sounds. By their first birthdays, babies start shifting back to look you in the eye again — unless they hear the unfamiliar sounds of a foreign language. Then, they stick with lip-reading a bit longer, according to the research.
"It's a pretty intriguing finding," said University of Iowa psychology professor Bob McMurray, who also studies speech development. The babies "know what they need to know about, and they're able to deploy their attention to what's important."
The new research offers more evidence that quality face-time with your baby is very important for speech development — more than, say, turning on the latest baby DVD.
In unraveling how babies learn to speak, neuroscientists want to find how to encourage that process, especially if it doesn't seem to be happening on time. It also helps them understand how the brain wires itself early in life to learn.