Talking to babies: How friendly eye contact can make infants tune in -- and mirror your brain waves

© 2018 GWEN DEWAR, PH.D., ALL RIGHTS RESERVED

How do children learn the secret of good communication?

It can't be too easy, because the world is rife with misunderstandings and crossed signals.

Too often, people go through the motions of exchanging information, but never really listen to each other.

In recent years, researchers have started to look inside the brain for answers. They've confirmed that good communicators don't just trade words; they also mirror each other's brain activity patterns.

And for babies, nonverbal cues play a crucial role during the process: Our direct gaze may be the signal that makes babies tune in and learn.

Here are the details--what researchers have learned about listening, synchronized brain activity, and talking to babies.

Using technology to peer in the brain

We can't open someone's skull and watch thoughts unfold. But brain scanning technology allows us to make helpful inferences.

For instance, we know that neighboring neurons fire together when they are working on a common task, and these group firings produce brain waves. If you wear a cap of electrodes, we can record these brain waves on an electroencephalogram, or EEG. Depending on what your brain is doing, you generate different EEG patterns.

Alternatively, we can use another method, functional magnetic resonance imaging (fMRI).  It allows us to infer patterns of brain activity by tracking blood flow in the brain.

Whichever method we choose, the really cool thing is that we can use it to study communication between brains.

For example, if I tell you a story--and you really listen--your patterns of brain activity will start to mirror mine.

Usually this happens after a brief delay (since you have to hear and process what I'm saying). But sometimes the mirroring goes in the other direction. You exhibit a distinctive brain pattern before I do--as if you are so tuned into my story, you can predict what words I will say next.

How can we be sure this matching is the result of communication? It appears that people match only when successful communication occurs.

After a storytelling session, Greg Stephens and his colleagues conducted exit interviews with listeners to test their comprehension. The people who performed well were those who experienced matching brain activity (measured by fMRI) during the communication session.

The people who showed poor comprehension were the ones whose fMRI's failed to match up with the storyteller's.

And those anticipatory brain patterns?  The more of those a listener experienced, the higher they scored on the comprehension test. (Stephens et al 2010).

So brain science provides us with an exciting new channel for studying communication. When we send messages to each other, the sender and receiver activate their brains in similar ways. Some of the same patterns required to encode the message are also used to decode it. The more closely we tune into each other, the more similar our brain activity becomes.

But what about babies? What does their brain activity look like? Do they have the ability to mirror?

This is an especially interesting question because babies are only beginning to learn language. We can't expect them to understand many of our words. We can't test their comprehension by asking them to tell us what we said.  But we know they are learning to communicate -- learning to pay attention to the things we are looking at, learning to engage us with eye contact, learning to read our emotional intentions, learning to infer the gist of our messages.

Talking to babies: Do babies mirror brain our brain waves?

Image from Leong lab by Cambridge University

Victoria Leong and her colleagues wanted to understand mirroring in infants, so they designed baby-friendly experiments using EEGs.

In the first experiment, the Leong's team presented 17 babies (approximately 8 months old) with three different video playbacks. Each featured the same woman singing a nursery rhyme, but the woman's body language differed from one condition to the next:

  • In one condition, the woman faced the camera head-on, and looked directly at the viewer.
  • In another condition, the woman's head was turned to the side, but her eyes continued to peer directly at the viewer.
  • In the third condition, her head was pointed to the side and her gaze was indirect.

During filming, the researchers recorded the woman's brain waves using electroencephalography. Then, during playbacks, they recorded the babies' EEGs as they watched. What were the results?

In each of the conditions where the woman made eye contact, the babies' brain activity mirrored that of the woman. But when the woman's gaze was averted, the brain waves didn't match.

The babies watched the woman just as much whether she made eye contact or looked away. So the mirroring wasn't merely the result of paying attention. Shared gaze appeared to be a crucial cue -- a signal that helped them tune in and synchronize brain waves.

Did the babies ever anticipate the woman's brain waves? There was no evidence of that. The mirroring was all one-way -- the woman's distinctive brain waves preceding those of the infants.  Maybe infants need more experience listening to these nursery rhymes, or need to be more familiar with the person singing them.

But the babies' brain waves were clearly matching those of the woman. And  researchers were curious about what would happen during a live interaction. How might the woman's brain activity change if she could see and hear the infant?

To answer, Leung's team conducted a second experiment that was similar to the first, except this time the woman and baby interacted live, in person, face-to-face.

In this case, not only did the babies track the woman's brain waves, the woman sometimes mirrored the babies' brain waves. And once again, the crucial cue was direct gaze. Adult and baby had to make eye contact for the brain waves to match up.

So both adults and babies use direct gaze as a cue for synchronizing brain activity, and this direct gaze is probably important for babies to learn.

Eye contact is a powerful sign that we intend to communicate something. It may -- metaphorically speaking -- open up the flood gates, allowing us to take in the details that a sender is trying to communicate.

How does it work? Scientists are still figuring that out. As I note above, it's likely that the brain performs similar tasks when sending and receiving a message. When you think and say, "I missed my train," your brain conjures up a series of meanings. When I hear you speak the words, I have to retrieve these meanings, which evokes similar activities in my own brain.

In the case of babies, they might not understand all the words, but facial expressions, body language, and vocal cues help convey our meaning. And eye contact may be the crucial signal that starts the process. Look here! I have a message for you. I want to interact.

The research is consistent with other studies of physiological synchronization.

In experiments conducted by Ruth Feldman and her colleagues, mother-infant pairs communicating face-to-face experienced frequent episodes of heart rhythm synchrony. In this case, the biggest predictor of heart synchronization wasn't direct gaze, but simultaneous, happy vocalizations and nonverbal signals of positive emotion (Feldman et al 2011).

And an experiment led by Sarah Waters used heart rhythms to show that babies can "catch" their parents' stressed-out moods. The researchers randomly assigned some mothers to attempt a stressful task -- public speaking -- and then reunited them with their infants. Within minutes of being reunited, mother-infant pairs showed matching cardiac responses, with babies mirroring the patterns of their stressed mothers (Waters et al 2014).

Taken together, these studies show us the power of eye contact, body language, and emotional cues. As I note elsewhere, such nonverbal signals help babies learn the meaning of words. But they also help children forge even more fundamental skills: How to tune into another person. How to understand his or her intentions. How to  empathize, and predict what someone is likely to do next.

When parents fail to provide timely cues -- because, for example, they are struggling with clinical depression, or suffering from anxiety -- there is less parent-child synchrony, and kids tend to have poorer outcomes (Leclère et al 2014).

So when we care for an infant, there is more at stake than meeting the child's immediate physical needs. And talking to babies does more than expose them to speech sounds.  The way we communicate  matters. It paves the way for deeper understanding -- for truly connecting to other people.

It's one more reason to treat our babies as conversation partners, and to get ourselves the emotional support we need. When our own mental health is good, we offer our babies more effective lessons in communication.

More information about talking to babies

For more information on this topic, check out these articles:

In addition, see this article about reducing stress in babies, which discusses the ways we can communicate a message of calm and confidence to our infants.


References: Talking to babies with nonverbal cues

Feldman R, Magori-Cohen R, Galili G, Singer M, Louzoun Y. 2011. Mother and infant coordinate heart rhythms through episodes of interaction synchrony. Infant Behav Dev.34(4):569-77.

Leclère C, Viaux S, Avril M, Achard C, Chetouani M, Missonnier S, Cohen D. 2014. Why synchrony matters during mother-child interactions: a systematic review. PLoS One. 2014 Dec 3;9(12):e113571.

Leong V, Byrne E, Clackson K, Georgieva S, Lam S, Wass S. 2017. Speaker gaze increases information coupling between infant and adult brains. PNAS 114 (50): 13290-13295

Stephens GJ, Silbert LJ, Hasson U. 2010. Speaker-listener neural coupling underlies successful communication. Proc Natl Acad Sci U S A. 107(32):14425-30.

Waters SF, West TV, Mendes WB. 2014. Stress contagion: physiological covariation between mothers and infants. Psychol Sci. 25(4):934-42.

Image credits for "Talking to babies":

Title image of baby touching father's face by HarshKR / flickr

Image of brain PET scan by Jens Langner / wikimedia commons

Image of woman and infant wearing electrode caps by Cambridge University

Image of baby eyeing mother over her shoulder by  Lars Ploughmann / flickr

Content of "Talking to babies" last modified 1/2018