| Summary: | Autism Spectrum Disorders (ASDs) are common developmental disorders thought to affect more than 1% of the UK population (Baird et al, 2006, The Lancet 368, 210). Whilst the current official diagnostic criteria for ASD concentrate on signs and symptoms associated with social behaviour, it is also well known that sensory difficulties are a major factor in the presentation of this condition (Simmons et al, 2009, Vision Research 49, 2705). Over the past few years we have been investigating these sensory symptoms of ASD using a combination of questionnaire and focus group data, with the aim of clarifying precisely what they are. Concentrating on the visual symptoms, our questionnaire data revealed that individuals with higher levels of autistic traits complained of more visual symptoms than those with lower trait levels. Specific issues highlighted included problems with bright light, especially artificial lighting and, more specifically, flicker from fluorescent lighting (a particular problem in supermarkets). Some individuals also complained of specific colours in artificial lights. Note that the symptoms associated with these aversions could be particularly strong and involve headache and nausea. The focus group (n = 6) of adults with ASD revealed more detail about these issues. It became clear that low-frequency visual flicker, once noticed, can be hard to divert attention from. Also, seeing certain colours (eg, red) would “hurt”. Another symptom reported by a number of individuals is distress caused by strongly repetitive patterns like shelving or grids. General sensory issues highlighted by the focus group included the importance of having control over sensory stimulation in order to reduce sensory stress and how certain types of sensory stimulation could be calming in some situations (although none of our sample reported visual calming experiences other than seeking out natural lighting). Our data provide a fascinating insight into the complex sensory world of individuals with ASD and are not readily explained by existing theories of ASD. There is also a conundrum in that behavioural measurements of sensory thresholds appear to show little difference between those with ASD and controls. We speculate that the strength of sensory symptoms in ASD might be closely involved with the more well-known social signs and symptoms that currently define it. Supported by an ESRC/CASE studentship and EPSRC. We also acknowledge further help and support from Carers Link East Dunbartonshire and Specialisterne Scotland.
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