February 14, 2012
Your Baby Understands More Than You May Realize
Researchers have found that infants, through their daily experience with language, learn and understand the meanings of words for foods and body parts.
Upending previous notions of language development in infants, children between the ages of six and nine months were shown to perceive and understand elements of the sounds of their native language. Previously, psychologists believed comprehension of words did not emerge until a child was closer to one year old.
First, a child sat on the caregiver´s lap facing a screen showing images of one food item and one body part. The caregiver, wearing headphones, heard a statement such as, “Look at the apple,” or, “Where´s the apple?” and then repeated it to the child. The caregiver also wore a visor to avoid seeing the screen. An eye-tracking device followed the child´s gaze.
The second test had the same set-up, except the screen displayed a food item and a body part, and displayed objects in natural contexts, such as a few foods laid out on a table, or a human figure.
For both kinds of test, the question was whether hearing a word for something on the screen would lead children to look at that object more, indicating that they understood the word.
A total of 33 babies, between six and nine months old were studied. A similar study was taken with 50 children from ten to twenty months of age to see how their abilities compared with the younger group.
In both the two-picture and scene tests, the researchers found that the six and nine month-old babies fixed their gaze more on the picture that was named than on the other image or images, indicating that they understood that the word was associated with the appropriate object.
This is the first demonstration that children of this age can understand such words.
Swingley explains, “There had been a few demonstrations of understanding before, involving words like mommy and daddy. Our study is different in looking at more generic words that refer to categories.”
“We´re testing things that look different every time you see them,” Bergelson added. “There´s some variety in apples and noses, and ℠nose´ doesn´t just mean your nose; it could mean anybody´s nose. This is one of the things that makes word learning complicated: words often refer to categories, not just individuals.”
The results of the study add to an ongoing debate about language acquisition and cognitive development in infants.
“I think it´s surprising in the sense that the kids at this age aren´t saying anything, they´re not pointing, they´re not walking,” Bergelson said. “But actually, under the surface, they´re trying to put together the things in the world with the words that go with them.”
“I think this study presents a great message to parents: You can talk to your babies and they´re going to understand a bit of what you´re saying,” Swingley said. “They´re not going to give us back witty repartee, but they understand some of it. And the more they know, the more they can build on what they know.”
The study is published in the early edition of this week's Proceedings of the National Academy of Sciences.
Image 2: A baby participates in the study of language acquisition. Credit: University of Pennsylvania
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