Making sense of the perceptual capacities in autistic and non-autistic adults

Abstract

Recent studies highlighted that autistic individuals show increased perceptual capacity – the ability to process more information at any one time. This study examined whether there is a link between this increased perceptual capacity and the sensory hypersensitivity that many autistic people experience on a daily basis. In total, 38 autistic and 66 non-autistic adults filled in sensory questionnaires and performed an auditory load task, which assessed perceptual capacity. Results showed that higher levels of auditory perceptual capacity were correlated with higher levels of sensory sensitivities. We identified two clusters in the sample: one group of individuals with hyposensitivity and a decreased perceptual capacity (n = 42) and a cluster with an increased perceptual capacity and hypersensitivity (n = 47). Understanding this relationship may offer the opportunity to develop more effective techniques to ameliorate the often debilitating consequences of sensory hypersensitivity and over-arousal. Interestingly, this association between perceptual capacity and sensory sensitivities was seen for both groups; no significant association was found between perceptual capacity and level of autistic traits. As such, the findings may extend to other conditions with sensory atypicalities, such as attention-deficit hyperactivity disorder or Williams syndrome. The practical implications of the results for many aspects of daily life, education and employment are discussed. Lay abstract: Perceptual capacity refers to the amount of information that we can pay attention to at any one time. Research has shown that autistic people have a higher perceptual capacity, which means they can take in more information than non-autistic people can. This can be useful in certain situations, for instance, hearing approaching cars or noticing small details. However, in other situations, a higher perceptual capacity may result in more distraction. This study looked at whether having this increased perceptual capacity is linked to being very sensitive to sensory information (lights, sounds, touch, taste and smell) – something that many autistic people experience on a daily basis. Being very sensitive to these things can make it hard to interact with the world around us, so it is important to know more about what causes the sensitivity. To explore this, 38 autistic and 66 non-autistic adults completed a computer task that measured perceptual capacity and filled in a questionnaire about how sensitive they were to sensory information. We found that perceptual capacity was related to sensory symptoms for both autistic and non-autistic participants; people who had a larger perceptual capacity showed more sensitivity, while people who had a lower perceptual capacity showed reduced sensory sensitivity. This information can hopefully be used to improve the way in which we can support people who experience unpleasant sensory sensitivity.