Reference: Romeo, R. R., Leonard, J. A., Robinson, S. T., West, M. R., Mackey, A. P., Rowe, M. L., & Gabrieli, J. D. (2018). Beyond the 30-million-word gap: children’s conversational exposure is associated with language-related brain function. Psychological Science, 29(5), 700-710.

In my last post, I discussed a study that explored the role of sustained attention within parent-child interactions in language development. Elements of adult-child interactions influence not only on the amount of words that children learn, but also their developing brains. What sort of influence does the way parents talk to their children have on children’s developing brains? In particular, how does brain development explain the relationship between the way parents talk to their children, and children’s developing vocabulary?

LENA: A snapshot into home language

Researcher Rachel Romero and her colleagues at the Massachusetts Institute of Technology (MIT) set out to answer these questions with creative methods. To discover how parents spoke with their children, the researchers obtained an audio recording of a weekend’s worth of conversation. Children ages 4-6 wore a device called LENA (Language ENvironment Analysis) to identify times when the parent or child was talking. The LENA system uses specialized algorithms, or sets of rules, to determine the total amount of words spoken by the parent and the child. It also measures the number of conversational turns — instances where one person talks and another person responds. For instance, if a child was to say, “Mom, what’s for dinner?”, and the mother responds, “We’re having pasta”, that would be one conversational turn. If the child was to then reply, “But I don’t like pasta”, there would now be 2 conversational turns. 

LENA provides an important “snapshot” into the child’s home language environment. However, as a measure of child language, LENA is limited to reporting the total number of words spoken by the child. LENA does not provide information about the complexity of the language the child is using. For more specific measures of language development, researchers had the children complete tests of their vocabulary and sentence-comprehension abilities. 

fMRI: A snapshot into developing brains

Finally, the researchers used a technique called fMRI to study brain development. fMRI is an imaging technique that provides information about brain activation during a particular experience (Read more about this technique here). In this study, the researchers read the children stories while in the fMRI scanner to examine how their brains responded to language. 

How do conversations lead to brain development?

To discover if the way parents talk with their children influences brain development, the researchers looked at how the number of conversational turns that LENA recorded related to brain activation during storytelling. They found that children who experienced a greater amount of conversational turns at home experienced greater levels of activation in brain regions responsible for language processing. However, the overall number of words a child or parent spoke at home was not related to brain activation when being read a story. 

Conversations, language abilities, and brain development

The researchers found that conversational turns were related to language-related brain activation. But how might this relationship explain differences in language development across children? The researchers found that when children experienced a lower number of conversational turns in an hour, they tended to score lower on tests of language comprehension. This result suggests a relationship between a child’s language environment and their language ability. 

But why does such a relationship exist? The researchers found that higher levels of conversational turns led to greater brain activation, which translates into greater verbal abilities for the child. Differences in brain activation explained about 50% of the relationship between conversational turns and a child’s verbal abilities. This means that differences in brain activation tells half of the story of how different conversation styles between parents and children lead to differences in verbal abilities. 

Children from lower social-economic status backgrounds tended to experience lower scores on verbal ability measures. The researchers found that brain activation and use of conversational turns also partially explains why these children had lower scores on measures of verbal ability. 

Conversations: Talking with children versus talking to children

Results from this study suggest that the language environment a child is exposed to early in life has an impact on the way the brain develops and processes language. More importantly, the quality of language and not the overall quantity of words spoken in the home plays an important role in language development. Brain activation during storytelling was predicted by conversational turns, or how often parents expanded on their child’s talk, rather than how much the parent spoke overall. To paraphrase the authors, parents should aim not only to talk to their children, but to talk with their children to maximize the child’s language development and associated brain development. 

How can you play an active role in a child’s language and brain development?

This research also supports the idea that when parents allow children a more active role in conversations, their language development increases.That is, the way parents interact with their children has a direct impact on their children’s brain development. When working in MRI research, I’ve seen parents become teary eyed upon seeing their child’s brain, saying — “I helped make that”. When children’s language begins to blossom, they also can know, “I helped make that”. Language provides a door into new worlds for children — opening up the ability to be friends with other children, engage in make-believe play, and develop emotional awareness that will prepare them for success at school. Next time you talk with a child, try to keep the conversation going, and know you are helping them along their language-development journey. 

Featured Images:

1. https://imgbin.com/png/S6Z3h9BN/human-brain-neuroscience-png
2. Collage made by blogger (Liz Glenn) with Canva: https://unsplash.com/photos/p_KJvKVsH14; https://pixabay.com/illustrations/brain-biology-abstract-cerebrum-951874/; https://pixabay.com/illustrations/nerve-cell-neuron-brain-neurons-2213009/; https://unsplash.com/photos/YLMs82LF6FY
3. Figure 4 from Romeo et al. (2018): https://doi.org/10.1177%2F0956797617742725
4. https://unsplash.com/photos/EMZxDosijJ4