Baby Talk: Early Social Interaction Spurs Language Growth

Summary: Early social interactions, characterized by “parentese,” smiles, and eye contact, significantly impact infant brain development and language growth.

Utilizing magnetoencephalography (MEG), the study observed increased brain activity in 5-month-olds during social interactions with adults, compared to nonsocial scenarios. This brain activity in regions associated with attention predicted improved language development up to 30 months of age.

Highlighting the importance of early social engagement, the findings suggest that such interactions not only strengthen the parent-child bond but also play a crucial role in the child’s linguistic and cognitive development.

Key Facts:

  1. Enhanced brain activity from social interactions at 5 months correlates with better language skills up to 2.5 years old.
  2. The study contrasts social interactions with nonsocial scenarios, emphasizing the impact of attention and engagement on learning.
  3. “Parentese” and positive feedback mechanisms like smiles and touch are pivotal for early language acquisition and brain development.

Source: University of Washington

A parent interacting with a baby is a heart-warming and universal scene. The parent speaks in a high-pitched voice — known as “parentese” — as they respond positively to the baby’s babbling and gestures, commonly with eye contact and smiles.

These connections don’t just make for a touching sight. New research from the University of Washington’s Institute for Learning & Brain Sciences (I-LABS) shows they’re important for infant language growth, too.

This shows a mom and baby.
They then monitored the infant’s brain activity a second time as the adult turned away and paid attention to someone else. Credit: Neuroscience News

In a study published April 8 in Current Biology, researchers used a safe and noninvasive brain-imaging technique called magnetoencephalography, or MEG, to monitor infant brain activity during social and nonsocial interactions with the same adult.

They found that when the adult talked and played socially with a 5-month-old baby, the baby’s brain activity particularly increased in regions responsible for attention — and the level of this type of activity predicted enhanced language development at later ages.

This ‘social’ scenario was compared with a ‘nonsocial’ scenario in which the adult turned away from the baby to talk to another person. This interaction showed lower activity levels in the same brain areas.

“This is the first study to directly compare infant brain responses to adult-infant social interaction versus nonsocial interaction, and then follow up with the children until they reached the age of 2.5 to see how the early brain activation relates to the child’s future language abilities,” said lead author Alexis Bosseler, research scientist at I-LABS.

The MEG brain-imaging technology allowed the baby to move and interact naturally with the adult, which enabled researchers to track the firing of neurons from multiple areas in the baby’s brain as the adult talked to, played with and smiled at the baby.

They then monitored the infant’s brain activity a second time as the adult turned away and paid attention to someone else.

These actions naturally occur every day between adults and babies, and the study showed they have different measurable effects on a baby’s brain.

Researchers found that increased neural activity in response to the social interaction at 5 months predicted enhanced language development at five later ages: 18, 21, 24, 27 and 30 months.

The researchers tracked infants’ language development using a well-documented and validated survey that asks parents about words and sentences their infants say at home.

“The connection between early brain reactions and later language is consistent with scientists’ fascination with the early age period and opens up many new questions that we, and others, will be exploring,” said co-author Andrew Meltzoff, I-LABS co-director and a UW professor of psychology.

Researchers chose 5-month-old babies for the study because that age is just before the “sensitive period” for speech-language learning, which begins at about 6 months. Once this period begins, it’s especially important for infants to observe adults because attention enhances learning.

Using parentese with infants represents an intuitive desire to connect, said Patricia Kuhl, senior author and co-director of I-LABS.

“There’s an implicit understanding that language is about connection,” Kuhl said. “It’s about a communicative pathway between you and the other. This starts in infancy with the desire to make that communicative connection.”

The study’s results are particularly important for parents and early educators to understand, Kuhl said.

“We knew from previous work that social interaction is essential at 9-months of age for foreign-language learning, but the current study shows that social interaction plays a role much earlier,” Kuhl said.

“The study shows that parents’ natural use of parentese, coupled with smiles, touch and their warm back-and-forth responses to the baby’s actions, have a real-world, measurable impact on the baby’s brain.

“We theorize that this parent behavior, which we call ‘the social ensemble,’ captures and holds infants’ attention and motivates them to learn at a critical time in development.”

Additional co-authors were Steven Bierer, Elizabeth Huber, Julia Mizrahi, Eric Larson, Yaara Endevelt-Shapira and Samu Taulu, all of I-LABS.  

Funding: The study was funded by The Bezos Family Foundation, the Overdeck Foundation and grants from the National Institutes of Health.

About this language and neurodevelopment research news

Author: Lauren Kirschman
Source: University of Washington
Contact: Lauren Kirschman – University of Washington
Image: The image is credited to Neuroscience News

Original Research: Open access.
Infants’ brain responses to social interaction predict future language growth” by Alexis Bosseler et al. Current Biology


Infants’ brain responses to social interaction predict future language growth


  • Adults interact with human infants using a species-specific social ensemble
  • Infant neural responses to social versus nonsocial interaction significantly differed
  • Brain areas involved in attention activate more strongly for the social condition
  • Individual variation in infant brain activation predicts language over 2 years later


In face-to-face interactions with infants, human adults exhibit a species-specific communicative signal. Adults present a distinctive “social ensemble”: they use infant-directed speech (parentese), respond contingently to infants’ actions and vocalizations, and react positively through mutual eye-gaze and smiling.

Studies suggest that this social ensemble is essential for initial language learning. Our hypothesis is that the social ensemble attracts attentional systems to speech and that sensorimotor systems prepare infants to respond vocally, both of which advance language learning.

Using infant magnetoencephalography (MEG), we measure 5-month-old infants’ neural responses during live verbal face-to-face (F2F) interaction with an adult (social condition) and during a control (nonsocial condition) in which the adult turns away from the infant to speak to another person.

Using a longitudinal design, we tested whether infants’ brain responses to these conditions at 5 months of age predicted their language growth at five future time points.

Brain areas involved in attention (right hemisphere inferior frontal, right hemisphere superior temporal, and right hemisphere inferior parietal) show significantly higher theta activity in the social versus nonsocial condition.

Critical to theory, we found that infants’ neural activity in response to F2F interaction in attentional and sensorimotor regions significantly predicted future language development into the third year of life, more than 2 years after the initial measurements.

We develop a view of early language acquisition that underscores the centrality of the social ensemble, and we offer new insight into the neurobiological components that link infants’ language learning to their early brain functioning during social interaction.

Join our Newsletter
I agree to have my personal information transferred to AWeber for Neuroscience Newsletter ( more information )
Sign up to receive our recent neuroscience headlines and summaries sent to your email once a day, totally free.
We hate spam and only use your email to contact you about newsletters. You can cancel your subscription any time.