If you want to know how children first learn to converse, have a word with Dr. Meghan Swanson.
As an assistant professor of psychology at The University of Texas at Dallas, Swanson pushes the boundaries of what we know about how infants begin to communicate. Her work in the School of Behavioral and Brain Sciences focuses on how brain development varies in children who are later diagnosed with autism spectrum disorder.
On May 14 at the annual meeting of the International Society for Autism Research, Swanson — along with UT Dallas cognition and neuroscience doctoral student Luke Moraglia — will present evidence that early language development for both neurotypical and atypical children uses resources from widespread areas of the brain — areas that extend beyond the regions associated with communication in adults.
“The project is provocative in that it challenges the way that people talk about language neurobiology,” Swanson said. “It discards the idea that when considering young children, you can rely on the classic model based on adults.”
The research project relies on MRIs and other imaging acquired by the Infant Brain Imaging Study (IBIS) Network, a consortium of 10 universities, including UT Dallas, in the U.S. and Canada that is investigating brain and behavior development of infants who have an older sibling with autism. IBIS, designated an Autism Center of Excellence project by the National Institutes of Health (NIH), received a $9.5 million grant from the NIH in 2019 to extend its mission to identify indicators of autism at an earlier age.
“Recent studies indicate that atypical brain development precedes the emergence of core features of autism,” Swanson said. “Our particular project set out to determine the relationship between brain surface area and cortical thickness at 6 months old and language skills at 24 months.”
“Study after study on early brain development has only looked at the classic language regions, and that misses half of the story. Our brains become specialized over time, in large part due to experience.”
Dr. Meghan Swanson, assistant professor of psychology in the School of Behavioral and Brain Sciences
The researchers took measurements of 239 6-month-olds, studying 78 brain regions via structural MRI. One hundred fifty-nine of the infants had older siblings diagnosed with autism, and 31 of those were later diagnosed. When the children were tested 18 months later, at the age of 2, the researchers found that there were regions outside the presumed language regions that were significant to later language skills, suggesting that future research on how infants learn to talk must take a broader view of the brain.
“Study after study on early brain development has only looked at the classic language regions, and that misses half of the story,” Swanson said. “Our brains become specialized over time, in large part due to experience. Infants learn language by recruiting large parts of their brains; true specialization happens after the age at which we’re studying them.”
When she first began her autism research 14 years ago, Swanson visited family homes across the New York City area, where she was conducting clinical trials involving shared toy play with autistic toddlers. It was a poignant experience, she said.
“I spent two years dragging suitcases full of toys, a camera and a tripod all across the city. You go into these homes to help, and I probably learned more from them than they learned from me,” she said. “Figuring out how to best support these families and these children was such a salient experience and guides my research to this day.”
Baby Brain Lab
The Infant Neurodevelopment and Language Research Lab at UT Dallas studies cognitive neuroscience in the early development of typically developing children and children with autism spectrum disorder. Researchers investigate the neurobiology of early language skills and how communication between infants and their parents affects brain development and later language and cognitive skills. Learn more about the team and its work.
Over time, Swanson’s research has honed in on how neurodivergent children learn language and how caregivers can support that process.
“I want to understand how their brains develop and how that contributes to them learning language,” she said. “I want to understand how parents talking to their children helps them learn language. I want to understand that process from all sides.”
All children learn language in part through joint attention — an adult and a child simultaneously focusing on the same thing.
“If the child doesn’t disengage from what they are doing and orient their eyes to the object that the parent is talking about, the child can’t properly map the word they are hearing to that object,” Swanson said. “It’s important to note that the differences we observe in the first year of life are not the core features that later distinguish autism. They are more fundamental processes.”
The first cohort of IBIS subjects has provided data for a variety of interesting studies. In a study published March 25 in The American Journal of Psychiatry, Swanson and 27 of her IBIS colleagues showed that children eventually diagnosed with autism exhibited markedly faster-than-normal growth in the brain’s amygdala between 6 and 24 months of age. This distinct, gradual neurological development path offers early indicators of autism’s genesis long before the hallmark traits of autism appear.
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“There’s evidence of the amygdala looking different in older autism populations, but this is the first exploration at this early age, the first two years of life, of how that comes to pass,” she said.
Swanson emphasized that the results don’t necessarily confirm a cause-and-effect relationship between amygdala overgrowth and later autism symptoms.
“The brain is a constant feedback system, always bidirectional,” she said. “The brain determines how you react to your environment, and your behavior influences how your world responds to you; our experiences shape our brain development. All these feedback loops exist; it’s very chicken-and-egg.”
Swanson emphasized that IBIS researchers like her are not aiming to eliminate or cure autism. She specifically is working toward interventions that help support adaptive language skills that are beneficial for all children.
“We used to think that the key to supporting language development was to focus on the social communication deficits, as opposed to sensory processing behaviors,” she said. “But this research and several other IBIS studies suggest that we may have a bigger impact by also focusing on these early sensory behaviors. Target the skill of orienting the eyes to an object, for instance. Tackle some of these basic processes that may not be functioning optimally, and then see if later on there are positive downstream effects on social communication.”
In addition to the NIH, the Psychiatry study was also supported by Autism Speaks and the Simons Foundation. Dr. Heather Hazlett and Dr. Joseph Piven were co-senior authors of the study, and Dr. Mark D. Shen was the corresponding author. All three are from the University of North Carolina at Chapel Hill School of Medicine.