Baby and adult brains 'sync up' during play

It's not your imagination -- you and your baby really are on the same wavelength

January 9, 2020

Science Daily/Princeton University

A team of researchers has conducted the first study of how baby and adult brains interact during natural play, and they found measurable connections in their neural activity. In other words, baby and adult brain activity rose and fell together as they shared toys and eye contact.

Have you ever played with a baby and felt a sense of connection, even though they couldn't yet talk to you? New research suggests that you might quite literally be "on the same wavelength," experiencing similar brain activity in the same brain regions.

A team of Princeton researchers has conducted the first study of how baby and adult brains interact during natural play, and they found measurable similarities in their neural activity. In other words, baby and adult brain activity rose and fell together as they shared toys and eye contact. The research was conducted at the Princeton Baby Lab, where University researchers study how babies learn to see, talk and understand the world.

"Previous research has shown that adults' brains sync up when they watch movies and listen to stories, but little is known about how this 'neural synchrony' develops in the first years of life," said Elise Piazza, an associate research scholar in the Princeton Neuroscience Institute (PNI) and the first author on a paper published Dec. 17, 2019, in Psychological Science.

Piazza and her co-authors -- Liat Hasenfratz, an associate research scholar in PNI; Uri Hasson, a professor of psychology and neuroscience; and Casey Lew-Williams, an associate professor of psychology -- posited that neural synchrony has important implications for social development and language learning.

Studying real-life, face-to-face communication between babies and adults is quite difficult. Most past studies of neural coupling, many of which were conducted in Hasson's lab, involved scanning adults' brains with functional magnetic resonance imaging (fMRI), in separate sessions, while the adults lay down and watched movies or listened to stories.

But to study real-time communication, the researchers needed to create a child-friendly method of recording brain activity simultaneously from baby and adult brains. With funding from the Eric and Wendy Schmidt Transformative Technology Grant, the researchers developed a new dual-brain neuroimaging system that uses functional near-infrared spectroscopy (fNIRS), which is highly safe and records oxygenation in the blood as a proxy for neural activity. The setup allowed the researchers to record the neural coordination between babies and an adult while they played with toys, sang songs and read a book.

The same adult interacted with all 42 infants and toddlers who participated in the study. Of those, 21 had to be excluded because they "squirmed excessively," and three others flat-out refused to wear the cap, leaving 18 children, ranging in age from 9 months to 15 months.

The experiment had two portions. In one, the adult experimenter spent five minutes interacting directly with a child -- playing with toys, singing nursery rhymes or reading Goodnight Moon -- while the child sat on their parent's lap. In the other, the experimenter turned to the side and told a story to another adult while the child played quietly with their parent.

The caps collected data from 57 channels of the brain known to be involved in prediction, language processing and understanding other people's perspectives.

When they looked at the data, the researchers found that during the face-to-face sessions, the babies' brains were synchronized with the adult's brain in several areas known to be involved in high-level understanding of the world -- perhaps helping the children decode the overall meaning of a story or analyze the motives of the adult reading to them.

When the adult and infant were turned away from each other and engaging with other people, the coupling between them disappeared.

That fit with researchers' expectations, but the data also had surprises in store. For example, the strongest coupling occurred in the prefrontal cortex, which is involved in learning, planning and executive functioning and was previously thought to be quite underdeveloped during infancy.

"We were also surprised to find that the infant brain was often 'leading' the adult brain by a few seconds, suggesting that babies do not just passively receive input but may guide adults toward the next thing they're going to focus on: which toy to pick up, which words to say," said Lew-Williams, who is a co-director of the Princeton Baby Lab.

"While communicating, the adult and child seem to form a feedback loop," Piazza added. "That is, the adult's brain seemed to predict when the infants would smile, the infants' brains anticipated when the adult would use more 'baby talk,' and both brains tracked joint eye contact and joint attention to toys. So, when a baby and adult play together, their brains influence each other in dynamic ways."

This two-brain approach to neuroscience could open doors to understanding how coupling with caregivers breaks down in atypical development -- such as in children diagnosed with autism -- as well as how educators can optimize their teaching approaches to accommodate children's diverse brains.

The researchers are continuing to investigate how this neural coupling relates to preschoolers' early language learning.

https://www.sciencedaily.com/releases/2020/01/200109163956.htm

Mind melding: Understanding the connected, social brain

March 26, 2019

Science Daily/Cognitive Neuroscience Society

Parents may often feel like they are not "on the same wavelength" as their kids. But it turns out that, at least for babies, their brainwaves literally sync with their moms when they are learning from them about their social environment. In a new study being presented at the Cognitive Neuroscience Society's (CNS) annual meeting in San Francisco this week, researchers found that how well babies' neural activity syncs with their moms' predicts how well they learn social cues about new toys.

"Despite the fact that this is such a powerful learning mechanism, surprisingly little is known about how the human brain performs social learning," says Victoria Leong, of the University of Cambridge. "When we connect neurally with others, we are opening ourselves to receiving information and influence from others."

In a body of new work being presented at the CNS meeting, cognitive neuroscientists are starting to shed light on the social brain and new ways to study it. "We're this massively social species and yet the field of neuroscience has focused on the brain in isolation," says Thalia Wheatley of Dartmouth College, who is chairing a symposium on the topic at CNS. "There's this huge gap in knowledge about how our brains work in concert with other minds."

Dissatisfied by the classical neuroimaging studies that put people in dark, loud, and isolated brain scanning machines to understand the human mind, Wheatley is working to come up with new methods to understand how brains behave in a social context. Social brains interact like a dance, Wheatley and Leong say, where partners take their own steps but move in concert, continuously adjusting and adapting.

At the CNS meeting, scientists presented work on the mother-infant and other social connections, as well as how even fruit flies have vivid social lives that require a new neural understanding.

The mother-baby connection

"There is no substitute for being physically present and in the moment to connect with an infant." That's the key message to come out of the new work by Leong and colleagues.

In the study, her team looked at how mothers' emotional responses toward novel toys affected their infants' decisions to interact with the toys. Infants wearing wireless EEG technology would watch their mothers, who were also wearing wireless EEG, show either a positive emotion -- e.g. smiling and saying "I like this" -- or a negative emotion toward an object -- e.g. frowning and saying "I don't like this." The babies would then choose which object to play with.

The researchers analyzed whether the level of "neural synchrony" between the mother and infant predicted how the infant would respond to a toy. "We found that stronger neural synchrony predicted a higher likelihood of social learning by the infant," Leong says. Neural synchrony is when brainwaves from two people follow predictable patterns with respect to each other. The researchers found that social signals like eye contact were associated with increased synchrony and improved social learning, though Leong says that there is still much work to be done in teasing apart exactly what leads to the neural synchrony.

Conducting EEG work with infants is challenging, Leong says, but rewarding. If they are ready and interested in the task, that resulting data is "like pure nectar. You feel like you've been granted exclusive backstage access to one of the most exciting reality shows on the planet," Leong says. "But on the other hand, if they are having a tummy ache, or are teething, or would just rather be left alone, this sentiment is expressed loudly, firmly, and with escalating urgency until the nice lady who is trying to put on a funny hat with wires retreats into a corner."

For Leong, the work has wide significance for classroom learning, social bonding, and developmental disorders. "I am interested in understanding what happens when parents or children fail to synchronize with each other, which may occur in certain mental health difficulties and developmental disorders, and the impact that this might have on learning and development in the longer term," she explains.

Common bonds

"The overarching goal of the symposium is to show that we and other species are social and there's something really important about looking at a brain in its social context," says Thalia Wheatley of Dartmouth. "We can't fully understand the human mind or any other social mind without understanding what happens in interaction."

While humans are an undisputedly social species, a growing amount of research is also showing sociality in unexpected species. "Most people don't think of fruit flies, for example, as being social at all," Wheatley says.

But, as Giovanni Bosco, also of Dartmouth College, will present at CNS, fruit flies communicate with each other with their wing patterns, and understanding their communication is key to understanding them. "Many fruit fly behavioral paradigms need to be revisited given our new appreciation of how social these animals are," Bosco says, because fruit flies used in research are raised in isolation and then do not behave as they would in nature. Simple strategies like co-housing them quickly changes their communication and behavior.

New methods are needed to better understand the social mind across species, Wheatley says. Indeed, says Leong, understanding interpersonal neural signals is "a new frontier that is ripe for exploration." Wheatley is currently working on a new method that allows people in fMRI scanners to talk to each other at the same time across different sites. "We are excited about creating new tools that will open up new ways to study the brain in interaction."

The symposium "An Emerging Neuroscience of Social Connectedness" is taking place at the CNS annual meeting in San Francisco.

https://www.sciencedaily.com/releases/2019/03/190326132708.htm