Sensory responsivity and its relation to alexithymia, social processing and restricted interests and repetitive behaviour in autistic children

Although noted in the earliest descriptions of autism, differences in sensory processing, including hyper-responsivity, hypo-responsivity and sensory seeking, have only been included as a diagnostic criterion more recently. Understanding how these unique features of sensory processing are related to the emotional and social aspects of autism is an ongoing question. Here we ask whether differences in sensory processing are associated with alexithymia , a trait characterised by an inability to identify and describe one’s feelings, which has a high incidence in autism. Parents of autistic children (n = 38) and parents of non-autistic children (n = 35) completed four standardized scales, the Short Sensory Profile-2, Social Responsiveness Scale-2, Social Communication Questionnaire, and the Children’s Alexithymia Measure. Across all four scales the autistic children showed higher scores than the non-autistic children, with large effect sizes. Using the subscales of the SSP-2 we show that, for the autistic children but not for the non-autistic children, sensory hyper-responsivity is predictive of alexithymia, of core social features of autism and of restricted interests and repetitive behaviour (RIRB), after controlling for hypo-responsivity and sensory seeking. These results add to a small but growing literature on the relationship between sensory processing and social and emotional behaviours in autistic children, and are discussed with reference to predictive coding and ‘sensory first’ accounts of autism. As sensory differences in autism impact children’s daily functioning and educational opportunities, understanding how these differences relate to social and emotional behaviour is important. • Both alexithymia and sensory processing differences are shown to have a high incidence in autistic children. • Hyper-responsivity predicts alexithymia, core social features of autism, and restricted interests and repetitive behaviour. • This pattern holds for autistic but not for non-autistic children. • These findings provide support for ‘sensory first’ and predictive coding accounts of autism.