Babies learn words differently as they age, researcher finds

"We found that babies' abilities to accurately guess the meaning of new words increases between 18 and 30 months of age, and by 24 to 36 months, toddlers are able to accurately guess the meanings of new words at a significantly higher level," said Judith Goodman, an associate professor in the MU School of Health Professions and chair of the Department of Communication Science and Disorders. "Interestingly, we observed that even from the time children mature from 18 to 30 months of age, the cues toddlers use to learn new words change."

In the study, researchers taught six new words to children, who ranged in age from 18 to 36 months, using three types of cues. The cues were presented alone or in pairs, and the researchers recorded the children's ability to accurately guess what the words meant.

"When children were presented with a new word and asked to choose between an item for which they already had a name and an unfamiliar object, they appropriately assigned the new word to the unfamiliar object, and this ability improved as children aged," Goodman said. "The toddlers' ability to infer a word's meaning from linguistic context, such as figuring out that a 'kiwi' must be a food item when they hear, 'Sammy eats the kiwi,' also improved as the children aged. However, using social cues, such as eye gaze, became less effective as the children matured. By 36 months of age, children were less likely to assume a word referred to the particular object a speaker was looking at -- looking at a kiwi when teaching the child the word 'kiwi' -- than younger children were."

Goodman also found that a limit exists as to how many words toddlers can retain. A day after the children learned the six words, the researchers tested whether the children remembered the words. The children better remembered the first three words they had learned the first day, Goodman said.

Children who are struggling with learning language may benefit from being presented with specific cues, Goodman said. Additionally, the research reinforces the importance of providing children with rich word-learning environments, in which toddlers are exposed to many words and are provided with a variety of cues to help them learn and remember those words and what they represent, Goodman said.

"When you're working with young children who are learning language, it's important to talk to them all the time and label everything in their environments," Goodman said. "At home, parents can name household items or foods the children are eating. If out on an excursion, such as a trip to the zoo, parents can label the animals they see."

The research was supported in part by the Student Research Grant in Early Childhood Language Acquisition from the American Speech-Language-Hearing Foundation.