Before they start talking, babbling babies ‘read’ mouths
Babies work hard to get ready to talk. They listen intently, and at around 6 months of age start to babble with passion while their brains figure out how to make sounds understood by others. A new study suggests babies might also learn to gab by using their eyes. Months before their babble becomes real words, babies watch people’s lips as they talk.
“Babies start to lip-read when they learn to babble,” David Lewkowicz, a psychologist who worked on the study, told Science News. At that time, he says, infants probably connect the sound of a word to the shape a person’s mouth makes when saying the word.
Lewkowicz and Amy Hansen-Tift, both of Florida Atlantic University in Boca Raton, conducted the experiments demonstrating babies’ lip-reading skills. The scientists studied 179 infants from families where English is the main language spoken at home.
The children, who were divided into groups by age, wore special devices while they watched videos of a woman speaking English or speaking Spanish, which was a foreign language to the babies. The device kept track of where the child looked while watching each video.
Babbling babies between ages 8 and 12 months old watched the speaker’s lips during every video. Babies who could talk also watched the speaker’s lips — but only while viewing Spanish videos. While watching the English videos, babies who could talk switched to watching the woman’s eyes. The scientists say these findings suggest that babies who already use words can look away from a speaker’s mouths and toward the eyes for additional, nonverbal communication clues.
The new study is useful for understanding how babies learn to speak, but it also might help researchers understand disorders like autism. Children with autism have a hard time communicating clearly and forming relationships with people. Previous studies have shown that children with autism watch people’s mouths and avoid eye contact by the time they’re 2 years old. The new experiments suggest that prolonged lip-reading in younger children, between 1 and 2 years old, may be an early sign of impending problems.
It’s too soon to know if a longer period of lip-reading might be connected to autism, Rhea Paul told Science News. Paul is a psychologist and autism researcher at Yale University. She says the new study demonstrates, however, that “it is normal for infants to increasingly look away from adults’ eyes and at their mouths from 6 to 12 months of age.
POWER WORDS (adapted from the New Oxford American Dictionary)
nonverbal Not involving words or speech.
autism A mental condition, present from early childhood, characterized by great difficulty in communicating and forming relationships with other people and in using language and abstract concepts.
psychology The scientific study of the human mind and its functions