New research has found that when it comes to the ability to regulate emotions, the brain activity in autistic people is significantly different from the brain activity in people without autism.
Researchers from the University of North Carolina School of Medicine say their findings suggest that improving prefrontal cortex activity could help autistic people regulate their emotions and improve serious symptoms associated with the disorder.
The findings, published in the Journal of Autism Developmental Disorder, show that “emotion regulation” symptoms have a biological explanation that can be visualized using functional MRI (fMRI).
The researchers contend that these emotional symptoms are not “merely associated” with or a result of the core autism symptoms, which include repetitive behaviors, communications problems, difficulties with social interactions, and other cognitive issues.
“This research adds to the growing awareness that although autism is diagnosed on the basis of social impairment and repetitive behaviors, the importance of emotion regulation and all the behaviors that come with it — depression, tantrums, meltdowns, irritability — are very real and should be a focus of clinical services,” said Gabriel Dichter, Ph.D., an associate professor of psychiatry and psychology and senior author of the paper.
“Any parent of a child with autism knows that these symptoms can be pervasive. Children with autism often lack the ability to cope with difficult emotional situations that result in meltdowns and tantrums.”
There are only two FDA-approved medications to treat autism and neither treats core symptoms, he said, noting they treat high rates of irritability and aggression.
“We’ve known for a while that we need to pay attention to emotion regulation in people with autism, but we think these data suggest a neural basis for these problems and add credence to their ubiquity as core features of the disorder,” he said.
For the new study, Dichter’s team recruited 30 young adults between the ages of 18 and 30; 15 had autism, the remaining 15 did not.
The researchers noted that because it is well documented that people with autism often have trouble regulating their emotions, they spent 45 minutes with each participant to teach them how to change their perception of an emotional stimulus before they entered the MRI scanner.
While in the fMRI scanner, each participant viewed a series of pictures of human faces with no expression. Partway through viewing each picture, the participants were asked to generate positive thoughts about the picture, or negative thoughts, or leave their emotional response unchanged.
The researchers also used eye-tracking to ensure all participants continuously viewed the picture and to measure at high resolution the size of each participant’s pupils. It’s known that pupils dilate when people exert cognitive effort, such as trying to recall someone’s name or trying to change an emotional response to situation, the researchers explained.
These methods, along with self-reporting from the participants, created checks and balances that ensured the accuracy of the data collected from the brain scans, the researchers reported.
The researchers discovered that in the control group, the prefrontal cortex worked hard to modulate the emotional response that originated in the limbic system — an evolutionarily old part of the brain associated with basic emotions and needs.
The brain scans of people with autism were different, according to the researchers.
“The prefrontal cortex did not come online to the same extent,” Dichter said. “It was as though the brain region that’s needed to work hard to regulate emotional responses couldn’t activate to the same degree as it did in people without autism. This limited activation of the prefrontal cortex, not surprisingly, resulted in less modulation of the limbic regions.”
The pupil data suggested that participants worked hard to fulfill the requirements of the study. They changed their emotional responses to the picture. But their brain scans suggest that people with autism did not use their prefrontal cortex to the same extent as people without autism.
When faced with emotional situations, since people with autism do not use their prefrontal cortices to regulate emotions, this may lead to the “associated symptoms” seen in many autistic people, such as anxiety, tantrums, and irritability, which can be pervasive, the researchers explained.
The research team also found a correlation between the level of brain activity in the prefrontal cortex and the severity of a person’s autism.
“There does seem to be an association between the ability to bring these brain regions online as needed during emotional situations and the severity of a person’s autism symptoms,” Dichter said.
Dichter next wants to conduct a similar study with children.
“Studying children with autism helps us tease apart the affects of having autism from the affects of living with autism for years as a teenager and an adult,” he said.
Future intervention research based on these findings could use cognitive behavior techniques to improve emotion regulation abilities for people with autism or brain stimulation techniques to improve activity in the prefrontal cortex during emotion regulation.