Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MRIs link impaired brain activity to inability to regulate emotions in autism

27.01.2015

UNC researchers find that the bigger the differences in brain activity related to emotion regulation, the more severe the autism

Tantrums, irritability, self-injury, depression, anxiety. These symptoms are associated with autism, but they're not considered core symptoms of the disorder. Researchers from the UNC School of Medicine are challenging this assertion. They have used functional MRI to show that - when it comes to the ability to regulate emotions - brain activity in autistic people is significantly different than brain activity in people without autism.


MRI data composite: the yellow indicates the prefrontal cortex areas that are significantly underactive in people with autism while regulating their emotions.

Credit: Gabriel Dichter, Ph.D., UNC School of Medicine

The findings, published online today in the Journal of Autism Developmental Disorder as part of a special issue on emotion regulation, suggest that improving prefrontal cortex activity could directly help autistic people regulate their emotions and improve serious symptoms associated with the disorder, which affects millions of people in the United States.

The discovery shows that "emotion regulation" symptoms have a biological explanation that can be visualized using fMRI. The symptoms do not seem to be merely associated with or a result of the core autism symptoms, which include repetitive behaviors, verbal and non-verbal communications problems, difficulties with social interactions, and other cognitive issues.

Gabriel Dichter, PhD, associate professor of psychiatry and psychology and senior author of the paper, said, "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."

"Any parent of a child with autism knows that these symptoms can be pervasive," added Dichter, who is a member of the Carolina Institute for Developmental Disabilities. "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; 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," Dichter said, "but we think these data suggest a neural basis for these problems and add credence to their ubiquity as core features of the disorder."

The Carolina Institute for Developmental Disabilities, directed by Joseph Piven, MD, is the umbrella program for autism research at UNC, which ranked second worldwide for the number of autism-related scientific papers published in 2012, the last time an intergovernmental agency issued the ranking.

The institute has a registry of more than 5,000 families with members who have been diagnosed with autism.

For this study, Dichter's team recruited 15 controls and 15 young adults, age 18 to 30, with autism. Because it is well documented that people with autism often have trouble regulating their emotions, Dichter's team spent 45 minutes with each participant to teach them how to change their perception of an emotional stimulus before they entered the MRI scanner.

During the study, while in the fMRI scanner, each participant viewed a series of pictures of human faces with no expression. Partway through viewing each picture, participants were asked to generate positive thoughts about the picture, or generate negative thoughts, or leave their emotional response unchanged.

The researchers also used eye-tracking methods 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.

These methods, along with self-reporting from participants, created checks and balances that ensured the accuracy of the data they collected from brain scans.

They found 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. This confirmed what other research had shown.

The brain scans of people with autism were different. "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.

Thus, when faced with emotional situations, people with autism do not use their prefrontal cortices to regulate emotions to the same extent as people without autism. This in turn may lead to the "associated symptoms," such as anxiety, tantrums, and irritability, which can be pervasive.

Dichter's 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.

Next, Dichter wants to conduct a similar study with children. "Studying children with autism helps us tease apart the effects of having autism from the affects of living with autism for years as a teenager and an adult."

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.

###

The first author of the Journal of Autism Developmental Disorder paper is John Richey, PhD, former postdoctoral fellow in Dichter's lab who was part of the T-32 training program at the Carolina Institute for Developmental Disorders. He is now an assistant professor at Virginia Tech. UNC graduate student Cara Damiano and former UNC graduate student Anna Sabatino, are also authors.

The study was funded by the National Institute of Mental Health and the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The study was also supported by the UNC-CH Graduate School Dissertation Completion Fellowship and the Clinical Translational Core of the Carolina Institute for Developmental Disabilities.

Dichter is also the director of UNC's Clinical Affective Neuroscience Lab.

Mark Derewicz | EurekAlert!

More articles from Health and Medicine:

nachricht Usher syndrome: Gene therapy restores hearing and balance
25.09.2017 | Institut Pasteur

nachricht MRI contrast agent locates and distinguishes aggressive from slow-growing breast cancer
25.09.2017 | Case Western Reserve University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Nerves control the body’s bacterial community

26.09.2017 | Life Sciences

Four elements make 2-D optical platform

26.09.2017 | Physics and Astronomy

Goodbye, login. Hello, heart scan

26.09.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>