Modality-specific associations of sensory deficits with autistic traits

Atypical sensory processing measured by self- or parent-report co-segregates with quantitative autistic traits (QAT) and has potential endophenotypic properties. It is not known whether this reflects a generalized sensory dysfunction or combinations of modality-specific mechanisms. We combined a Bayesian variable selection method with dominance analysis to obtain a more nuanced understanding of modality-specific associations. We recruited two independent cohorts of adults online to complete the Broad Autism Phenotype Questionnaire and the Glasgow Sensory Questionnaire (GSQ). For each QAT, we performed stochastic search variable selection (SSVS) on GSQ subscales to test which modalities predicted QAT while controlling for uncertainty in the other variables. Dominance analysis was applied to the models identified by SSVS to evaluate the modalities' relative importance in predicting QAT. Only auditory scores reliably predicted all QATs when other modalities were accounted for. The proprioceptive scale, which included motor and interoceptive deficits, specifically predicted communicative QAT. The tactile scale, which included atypical touch/pain/temperature processing, specifically predicted social QAT. Although the findings must be interpreted in light of the limitations of the questionnaires, the study suggests that deficits in the auditory modality may be more likely than those in other senses to be a sensory endophenotype relevant to autism.