Sensory Perception in Autism Spectrum Conditions: a brief research update

Many people on the autism spectrum report having difficulties or differences in sensory perception. For example, in Temple Grandin’s famous book “Thinking In Pictures” she describes her sensory experiences the following: “From as far back as I can remember, I always hated to be hugged. I wanted to experience the good feeling of being hugged, but it was just too overwhelming. It was like a great, all-engulfing wave of stimulation, and I reacted like a wild animal”(1). Temple Grandin also highlights the high variability seen in sensory perception across ASC: “Over the years I have observed that sensory sensitivities in autism are highly variable. One child will love to play with running water, and another autistic child will run away and scream when a toilet flushes”. Anecdotal reports provide valuable information and help us to understand how people with ASC perceive the world differently, however they are not quantitative and can not reveal underlying mechanisms of sensory processing differences. One important question is at what level are people with ASC experiencing sensory differences? Is it at a low-level, e.g. are individuals with ASC better able to detect small differences in vision, hearing, smell or taste? Or at a high-level of perception, e.g. individuals with ASC might interpret sensory stimuli differently, such as a light touch on the shoulder (i.e. their sensory receptors perceive touch in the same way, but their brain interprets it as more intense). Several research methods have been used to quantify and describe sensory processing difficulties in ASC and attempt to answer some of these important questions. These methods include sensory questionnaires, observations, experimental studies and neuroimaging studies for example.