Back-and-forth exchanges boost children’s brain response to language

Study finds engaging young children in conversation is more important for brain development than “dumping words” on them.

MIT cognitive scientists have found that conversation between an adult and a child appears to change the child’s brain.
MIT cognitive scientists have found that conversation between an adult and a child appears to change the child’s brain.

A research drove by scientists of MIT discovered that conversation between an adult and a child seems to change the child’s brain and that this back-and-forth conversation is concretely more delicate to language development than the word gap.

A landmark 1995 study found that children from higher-income families hear about 30 million more words during their first three years of life than children from lower-income families. This “30-million-word gap” correlates with exceptional differences in tests of vocabulary, language development, and reading comprehension.

In previous study little was recognized about how the “word gap” might translate into differences in the brain. The MIT team set out to find these differences by comparing the brain scans of children from different socioeconomic backgrounds.

As part of the study, the researchers utilized a system called Language Environment Analysis (LENA) to record every word spoken or heard by each child. Parents who agreed to have their children partake in the study were told to have their children wear the recorder for two days, from the time they woke up until they went to bed.

The recordings were then analyzed by a computer program that yielded three measurements as the number of words spoken by the child, the number of words spoken to the child, and the number of times that the child and an adult took a “conversational turn” ( a back-and-forth exchange initiated by either one).

The researchers discovered that the number of conversational turns correlated strongly with the children’s scores on standardized tests of language skill, including vocabulary, grammar, and verbal reasoning. The number of conversational turns likewise correlated with more activity in Broca’s area when the children listened to stories while inside a fMRI scanner.

These correlations were much stronger than those between the number of words heard and language scores, and between the number of words heard and activity in Broca’s area.

In a recent study of children between the ages of 4 and 6, scientists discovered that differences in the number of “conversational turns” accounted for a major part of the differences in brain physiology and language skills that they noticed among the children.

This finding put in the application to children regardless of parental income or education.

The researchers say whereas these findings suggest that parents can have a significant impact on their children’s language and brain advancement by simply engaging them in conversation.

Rachel Romeo, the lead author of the paper said, “The important thing is not just to talk to your child, but to talk with your child. It’s not just about dumping language into your child’s brain, but to actually carry on a conversation with them.”

During the study utilizing functional magnetic resonance imaging (fMRI), the researchers recognized differences in the brain’s reactions to language that correlated with the number of conversational turns. In children who accomplished more conversation, Broca’s area, a part of the brain involved in speech production and language processing, was much more prompt while they listened to stories.

This brain activation then predicted children’s scores on language assessments, fully explaining the income-related differences in children’s language skills.

John Gabrieli, the Grover M. Hermann Professor in Health Sciences and Technology, a professor of brain and cognitive sciences, said, “The really novel thing about our paper is that it provides the first evidence that family conversation at home is associated with brain development in children. It’s almost magical how parental conversation appears to influence the biological growth of the brain.”

This result arrays with other recent discoveries, Romeo says, “but there’s still a popular notion that there’s this 30-million-word gap, and we need to dump words into these kids — just talk to them all day long, or maybe sit them in front of a TV that will talk to them. However, the brain data show that it really seems to be this interactive dialogue that is more strongly related to neural processing.”

The researchers believe interactive conversation gives children more of an opportunity to practice their communication skills, including the ability to understand what another person is trying to say and to respond in a correct way.

While children from higher-income families were exposed to more language on average, children from lower-income families who experienced a high number of conversational turns had language skills and Broca’s area brain activity similar to those of children who came from higher-income families.

Gabrieli states, “In our analysis, the conversational turn-taking seems like the thing that makes a difference, regardless of socioeconomic status. Such turn-taking occurs more often in families from a higher socioeconomic status, but children coming from families with lesser income or parental education showed the same benefits from conversational turn-taking.”

The researchers say the researchers hope their findings will encourage parents to engage their young children in more conversation. Although this study was done in children age 4 to 6, this type of turn-taking can also be done with much younger children, by making sounds back and forth or making faces.

Gabrieli added, “One of the things we’re excited about is that it feels like a relatively actionable thing because it’s specific. That doesn’t mean it’s easy for less educated families, under greater economic stress, to have more conversation with their child. But at the same time, it’s a targeted, specific action, and there may be ways to promote or encourage that.”

Roberta Golinkoff, a professor of education at the University of Delaware School of Education, says the new study presents an important finding that adds to the evidence that it’s not just the number of words children hear that is significant for their language development.

Golinkoff, who was not involved in the study, said, “You can talk to a child until you’re blue in the face, but if you’re not engaging with the child and having a conversational duet about what the child is interested in, you’re not going to give the child the language processing skills that they need.”

“If you can get the child to participate, not just listen, that will allow the child to have a better language outcome.”

The MIT researchers now hope to study the impacts of possible interventions that incorporate more conversation into young children’s lives. These could include technological assistance, such as computer programs that can converse or electronic reminders to parents to engage their children in conversation.