In the study of children between the ages of four and six, researchers found that differences in the number of “conversational turns” accounted for a large portion of the differences in brain physiology and language skills that they found among the children.
Using functional magnetic resonance imaging (fMRI), the researchers identified differences in the brain’s response to language that correlated with the number of these turns.
Dr Romeo says the software defines a conversational turn as an adult speaking and a child responding (or a child speaking and an adult responding) with no more than a five second pause in between.
Mum says: "What would you like for dinner?" and the child says "Spaghetti!" = one turn
Child says: "Can we have spaghetti tonight?" and the mum says "No, we had that last night." And the child says "Okay." = 2 turns
As part of the study, MIT researchers used a system called Language Environment Analysis (LENA) to record every word spoken or heard by each child. Parents who agreed to have their children participate 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 analysed by a computer program that yielded three measurements: 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 found 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.
Dr Romeo says children who experienced more conversation (over 150 turns per hour) scored 12% higher on standardized language assessments.
The number of conversational turns also correlated with more activity in Broca’s area, a part of the brain involved in speech production and language processing, when the children listened to stories while inside an fMRI scanner.
Dr Romeo says even the youngest children are able to engage, non-verbally, in conversation.
“When adults talk with them, rather than just at them, babies are surprisingly competent turn takers, listeners and even initiators of interactions.
“Using eye contact, gestures, facial expressions, babbling and other sounds, babies are more than capable of engaging in two-way conversation.”
Dr Romeo says when adults are attuned to each child’s ways of communicating, such conversations can be as rich and meaningful as the more verbal conversations we have with older children.
As children grow older, parents are advised to sustain conversations with their children, adding depth and giving their children more time to practise, understand and engage in language and communication successfully.
The paper found that conversational turns may be particularly important for language development because they provide increased opportunities for children to practise language and receive feedback from adults.
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 significant differences in tests of vocabulary, language development, and reading comprehension.
MIT cognitive scientists now believe that conversation between an adult and a child appears to change the child’s brain, and that this back-and-forth conversation is actually more critical to language development than the word gap.
This result aligns with other recent findings, Dr 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.”
In the study, the differences were found to apply to children regardless of parental income or education.
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.
“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,” Professor Gabrieli says.
The researchers hope their findings will encourage parents to engage their young children in more conversation. Although this study was done in children aged four to six, this type of turn-taking can also be done with much younger children, by making sounds back and forth or making faces, the researchers say.
“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,” Professor Gabrieli says.
Roberta Golinkoff, a professor of education at the University of Delaware School of Education, was not involved in the study, but reviewed the findings and says the study adds to the evidence that it’s not just the number of words children hear that is significant for their language development.
“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,” says Professor Golinkoff.
“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 effects 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.