Summary: A new study reports some people on the autism spectrum show neural signs of anxiety when presented with images of people engaging in social touch, such as hand holding.
Source: University of Haifa.
People with strong signs of autism spectrum disorder (ASD) show neural signs of anxiety when they see social touch and report unpleasant feelings about social touch by comparison to people with weak signs of ASD. This finding has emerged from a new study undertaken at the University of Haifa. “Until now, it was clear that many people with ASD dislike touch. This study enables us to understand that they actual experience touch in a similar way to anxiety,” explains Leehe Peled-Avron, a doctorate student in the Department of Psychology, who undertook the study.
The autism spectrum is a developmental disorder characterized by difficulties in creating, understanding, and maintaining social relationships. Some 70-80 percent of people with ASD suffer from hypersensitivity or undersensitivity to neural stimulation through the various senses, including sight, touch, and taste. Some parents of children with ASD report that their children stiffen when touched, try to avoid touch, and prefer to be touched on their own terms. Until now, however, researchers did not understand exactly what causes this sensitivity, and above all – how people with ASD feel when they are exposed to touch.
The present study, published in the prestigious journal Autism Research, was authored by Prof. Simone Shamay-Tsoory and doctorate student Leehe Peled-Avron from the Department of Psychology at the University of Haifa. The researchers sought to examine the differences in the neural response to social interaction, including human touch, between people with ASD and people without the disorder.
Fifty-four participants were divided into two groups: one group of people with ASD who have a high level of social functioning, and one group without signs of ASD. The participants were shown 260 pictures in four categories: social touch between two people photographed in natural conditions, such as malls, parties, social events, and so forth; social interaction between the same people without touch; two everyday inanimate objects touching; and two inanimate objects not touching.
The results of the study show that people with ASD reported unpleasant sensations when they watched social touch, compared to people without ASD. The examination of their brain waves showed that when they watched social interaction including touch, the neural signals in their brain were ones that we recognize as signals of someone in a state of anxiety. It was also found that these neural signals of anxiety increase the stronger the patterns of ASD. In other words, the higher a person is diagnosed on the autistic spectrum, the stronger their neural signals, possibly reflecting a greater level of anxiety at social touch. When the participants watched the same social interactions without touch, these signals were not present, showing that it was the element of touch that created the anxiety, and not the social interaction. “Similar neural signals to those we found have been reported in studies on phobias. If someone suffers from a specific trauma and we show them the traumatic object, the neural signals that result are identical to those we found in the study,” Peled-Avron explains.
“The results of this study improve our understanding of people diagnosed with ASD. Social touch is an integral part of our lives, in both happy and sad events, and now we can understand why for some people on the autistic spectrum all these events arouse anxiety. As well as understanding them, this insight may be very helpful for therapists, who can offer therapy focusing on anxiety in a similar manner to therapy for phobias, whether by means of psychotherapy or medication,” the researchers concluded.
Source: Ela Kehat – University of Haifa
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Abstract for “Don’t touch me! autistic traits modulate early and late ERP components during visual perception of social touch” by Leehe Peled-Avron and Simone G. Shamay-Tsoory in Autism Research. Published online June 6 2017 doi:10.1002/aur.1762
Don’t touch me! autistic traits modulate early and late ERP components during visual perception of social touch
Although individuals with autism spectrum disorder (ASD) have impaired responses to interpersonal touch, the underlying neural correlates remain largely unknown. Here, we examined the neural correlates that underlie interpersonal touch perception in individuals with either high or low autistic traits. Fifty-three participants were classified as having either high or low autistic traits based on their performance on the autism quotient (AQ) questionnaire. We hypothesized that individuals with high AQ scores would have relatively high touch hypervigilance, reflected as earlier P1 and stronger late positive potential (LPP) responses, two components of event-related potentials that serve as electrophysiological markers of anxiety bias. We recorded each participant’s electroencephalography activity during presentation of images depicting human touch, object touch, and non-touch control images. Consistent with our hypothesis, AQ scores were positively correlated with social touch aversion. Moreover, participants with high AQ scores had earlier P1 and stronger LPP responses when presented with human touch compared to the control images. Importantly, a regression model revealed that earlier P1 and larger LPP amplitude measured during social touch observation can accurately predict higher autistic trait levels. Taken together, these findings indicate that individuals with high levels of autistic traits may have a hypervigilant response to observed social touch.
“Don’t touch me! autistic traits modulate early and late ERP components during visual perception of social touch” by Leehe Peled-Avron and Simone G. Shamay-Tsoory in Autism Research. Published online June 6 2017 doi:10.1002/aur.1762