A few years back, I remember advising a mother to let her son try out clothes of different materials. Her son was a five-year-old with Autism Spectrum Disorder (ASD). He would constantly fiddle with his shirts, shorts, and pants, flap his hands (stimming), and get upset whenever his mother brought out particular clothes to wear. It was a consistent pattern and routine that both mother and son went through almost every morning before school, until I explained that certain materials could be causing him to feel ‘itchy’. Through trial and error, we figured out the materials he was and was not comfortable with, and both mother and son saw calmer mornings.
Her son, just like many other children with both ASD and sensory issues, is hypersensitive to feeling objects on his skin, in this case, clothing material or texture. Common repetitive behaviours usually observed in children with ASD include rocking, headbanging, and echolalia (repeating sounds and words). The frequency and severity of such behaviours would increase and decrease depending on what they are responding to.
But why do we commonly observe such repetitive behaviours in children with ASD and sensory issues? Could there be a link between sensory disorders and repetitive behaviours?
Dysfunctions in Neurobiological Mechanisms
When we live in the world, our bodies are constantly reacting to our environments in some way. Such a process starts from the sensory receptors in our body, which are receiving the input, to the neural pathways carrying the signals to and from our brain. In children with ASD and other sensory disorders, there have been dysfunctions observed in one or many parts of the process, be it deficits in the receptors, neural pathways and/or the processing of information. Studies have also examined how an elevation or a decrease in certain types of brain waves in different parts of the brain is linked with either the hypersensitivity and hyposensitivity in children with ASD (Gabard-Durnam et al., 2015; Simon et al., 2017; Stroganova et al., 2007). Due to such dysfunctions, they may feel either overstimulated or understimulated. Being on the extreme ends of stimulation, they may exhibit behaviours differently from children who do not have sensory difficulties. For example, children with ASD may cover their ears, flap their arms, jump, or rock themselves if they hear sounds that may seem too loud in a crowded place.
Effects of Context and Reinforcement on Behaviours
While we have internal neurobiological mechanisms to guide us in responding to objects and people around us, there is also the law of effect that revolves around the consequences of our behaviours. In other words, the positive or negative responses from others can determine whether behaviours will be repeated or not (Skinner, 1948). For example, when parents compliment their children for a deed like helping out with chores or sitting quietly while waiting, children will repeat the behaviour in hopes of getting the positive response again.
Furthermore, in a context where the child with ASD is familiar with the stimulus, he will not exhibit such repetitive behaviours due to not having the need to cope with overstimulation or a lack thereof (Ashburner et al., 2013, Schaaf et al., 2011). This also opens a window of discussion that repetitive behaviours displayed by children with ASD could perhaps be a coping strategy when dealing with sensory issues. This can be observed in cases where children with ASD may be comfortable in familiar settings like home and school where they can perform tasks or converse with others with ease as compared to unfamiliar settings like shopping malls.
Coming back to the topic of finding the link between sensory disorders and repetitive behaviours - the dysfunctions in internal brain mechanisms and effects of external factors can explain the link between sensory issues and repetitive behaviours in children with ASD. Due to overstimulation or a lack thereof, the sensory issues are what cause repetitive behaviours to occur. However, if we could observe them in different contexts with different objects and people, such stereotyped repetitive behaviours may not always be present. As the concept of repetitive behaviours being a way of coping with sensory issues is not discussed much, I feel that we can explore and conduct more research in this area. Although there has been a range of research contributing to the field of ASD, it is a wide spectrum where no two individuals with autism are the same, even if there may be overlaps in certain traits and behaviours. As such, I think it is important for us to also pay attention to the individualities of those with ASD beyond preconceived stereotypes to better understand them and improve the support that can be given.
Written by Alisha.
References
Ashburner, J., Bennett, L., Rodger, S., & Ziviani, J. (2013). Understanding the sensory experiences of young people with autism spectrum disorder: A preliminary investigation. Australian Occupational Therapy Journal, 60(3), 171-180. Retrieved from:
http://sensory-processing.middletownautism.com/wp-content/uploads/sites/3/2015/07/Ashburner-2013.pdf
Gabard-Durnam, L., Tierney, A. L., Vogel-Farley, V., Tager-Flusberg, H., & Nelson, C. A. (2015). Alpha asymmetry in infants at risk for autism spectrum disorders. Journal of Autism and Developmental Disorders, 45(2), 473-480. doi: 10.1007/s10803-013-1926-4
Schaaf, R. C., Toth-Cohen, S., Johnson, S. L., Outten, G., & Benevides, T. W. (2011). The everyday routines of families of children with autism: Examining the impact of sensory processing difficulties on the family. Autism, 15(3), 373-389. Retrieved from:
Simon, D. M., Damiano, C. R., Woynaroski, T. G., Ibañez, L. V., Murias, M., Stone, W. L., ... & Cascio, C. J. (2017). Neural correlates of sensory hyporesponsiveness in toddlers at high risk for autism spectrum disorder. Journal of Autism and Developmental Disorders, 47(9), 2710-2722. doi: 10.1007/s10803-017-3191-4
Skinner, B. F. (1948). 'Superstition' in the pigeon. Journal of Experimental Psychology, 38(2), 168. Retrieved from:
Stroganova, T. A., Nygren, G., Tsetlin, M. M., Posikera, I. N., Gillberg, C., Elam, M., & Orekhova, E. V. (2007). Abnormal EEG lateralization in boys with autism. Clinical Neurophysiology, 118(8), 1842-1854. doi: 10.1016/j.clinph.2007.05.005