Tactile and Auditory Hypersensitivity in Individuals with Autism Spectrum Conditions

Background: Anecdotal reports suggest sensory differences in autism spectrum conditions (ASC). In addition, studies using questionnaires such as the Sensory Profile have revealed sensory abnormalities in over 90% of children with ASC.

Objectives: This study explores sensory sensitivity using detection tasks in both touch and hearing in female and male adults with and without ASC. We aim to test: (1) if adults with ASC show hyper-sensitivity in both auditory and tactile modalities; (2) if such hypersensitivity is correlated across modalities.

Methods: 20 adults (8 females, 12 males) with a prior diagnosis of ASC were matched to 20 adult controls (8 females, 12 males) on age, sex and IQ. The Semmes Weinstein Von Frey Aesthesiometer for Touch Assessment, and the Audio-CD for auditory threshold measurement were used to measure tactile and auditory sensitivity respectively. The Autism Spectrum Quotient (AQ) was used to measure autistic traits.

Results: The ASC group was significantly more sensitive to tactile stimulation than the control group (U = 99.5, p < 0.005). The effect size was large (Cohen's d=3.9, r= 0.89) The ASC group also showed significantly higher auditory sensitivity at high frequencies (above 16K Hz) (F=6.43, p=0.015). Tactile and auditory sensitivity were positively correlated for both ASC and controls (Spearman’s rho = .453, p = .004).

Conclusions: This study confirms hypersensitivity to touch and hearing at high frequencies in the same individuals with and without ASC, and that sensitivity in both modalities is correlated with each other. These findings suggest that hypersensitivity may be a core feature of the ASC phenotype. This has implications for the design of ASC-friendly sensory environments, diagnostic tools and for future genetic research.