Relationship Between Social Severity and Sensory Processing in Children with High Functioning Autism Spectrum Disorders

Background: Although diagnostic criteria for autism does not include sensory processing deficits, literature describes many sensory processing abnormalities for these children.  Researchers have identified modulation difficulties including both hyposensitivities and hypersensitivities to a variety of sensory stimuli in children with autism (Dunn, Smith Myles, & Orr, 2002; Liss, Saulnier, Fein, & Kinsbourne, 2006; Myles et al., 2004). 

Objectives: This study examined the relationship between social severity and sensory processing in children with high functioning autism spectrum disorders (HFASD).

Methods: Study methods were in compliance with the guiding policies and principles for experimental procedures endorsed by the National Institute of Health.  A linear regression design was used to compare the scores between a social severity assessment and a sensory processing assessment of children with HFASD. Children with HFASD (N = 36), and a control group (N = 26), ages 6 to 10, participated in the study.  The participants were full-term, had an overall reported IQ of at least 70, and had no history of cerebral palsy, or any other diagnosed major neurological condition. 

The Social Responsiveness Scale (SRS, Constantino & Gruber, 2005), a quantitative trait measure of autistic social impairment was collected from the parent perspective and used to assess social severity.  The Sensory Profile (SP, Dunn, 1999), a 125-item questionnaire that describes responses to sensory events in daily life and measures the degree to which children exhibit problems in sensory processing, modulation, behavioral and emotional responses and responsiveness to sensory events, was used to assess sensory processing. 

Results: Definitely atypical responses in at least one sensory system (auditory, visual, vestibular, touch, multisensory, and oral sensory) were seen in 100% of the severe HFASD subjects, 60% of the mild to moderate, and 23% of the typical subjects.  Definitely atypical responses in at least three of the six sensory systems were seen in 63% of severe, 30% of mild to moderate, and none of the typical subjects.  Moderate to strong correlations were found between the SRS scores and each of the six sensory system scores.  Regression analysis indicated a significant predictive relationship between the six sensory system scores and the SRS raw scores, with an R square value of .709, with multisensory processing and touch processing having the strongest predictive relationship to the SRS raw scores.
Conclusions: The relationship between the SP sensory system scores and the SRS scores indicates that auditory, visual, vestibular, touch, multisensory, and oral sensory processing are related to autism severity and have significant importance for understanding the neurobiology of autism.