In Autism Some More Sensitive to Stimuil than OthersOne of the symptoms of autism spectrum disorder (ASD) is hyper-sensitivity to sensory stimuli. A study from the University of California, Los Angeles (UCLA) recently investigated the brain responses of young people with ASD to auditory and tactile stimuli. They found that some people with ASD have exceptionally sensitive reactions to stimuli, a condition called sensory over-responsivity. For these young people, the brain reacts differently from those of young people with just ASD. The study may lead to new treatments for sensory processing for people with ASD.

The researchers conducted functional magnetic resonance imaging (fMRI) of young people aged 9 to 17, analyzing their brain patterns in response to sensory stimuli. The researchers exposed the participants—some with ASD and some without—to three types of sensory stimuli: loud noise, scratchy fabric rubbed on the arm, and both noise and scratchy fabric simultaneously.

All of the participants had a similar initial brain response to the stimuli, but differences between the youth without ASD, youth with ASD, and youth with ASD and sensory over-responsivity quickly emerged. The participants with ASD took longer to get used to the stimuli than those without ASD. There were significant differences between the brain responses in the participants with ASD and the participants who also had sensory over-responsivity. Participants with sensory over-responsivity had stronger brain responses to sensory stimuli in the amygdala, which plays a role in emotional reactions. Participants with ASD and without sensory over-responsivity had a brain response that was more similar to that of the participants without ASD.

“Our research provides new insights into the brain differences that may cause sensory over-responsivity, which helps us understand how to treat it—from simple interventions like limiting exposure to multiple sensory stimuli to more complex interventions like cognitive-behavioral therapy,” explained the study’s first author, Shulamite Green, postdoctoral fellow in the Semel Institute for Neuroscience and Human Behavior at UCLA.

This research is published in JAMA Psychiatry.

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