Atypical Perception of Sounds in Minimally and Low Verbal Children and Adolescents With Autism as Revealed by Behavioral and Neural Measures.

The common display of atypical behavioral responses to sounds by individuals with autism (ASD) suggests that they process sounds differently. Within ASD, individuals who are minimally or low verbal (ASD-MLV) are suspected to have greater auditory processing impairments. However, it is unknown whether atypical auditory behaviors are related to receptive language and/or neural processing of sounds in ASD-MLV. In Experiment 1, we compared the percentage of time 47 ASD-MLV and 36 verbally fluent (ASD-V) participants, aged 5-21, displayed atypical auditory or visual sensory behaviors during the administration of the Autism Diagnostic Observation Schedule (ADOS). In Experiment 2, we tested whether atypical auditory behaviors were more frequent in ASD-MLV participants with receptive language deficits. In Experiment 3, we tested whether atypical auditory behaviors correlated with neural indices of sensitivity to perceptual sound differences as measured by the amplitude of neural responses to nonspeech intensity deviants. We found that ASD-MLV participants engaged in atypical auditory behaviors more often than ASD-V participants; in contrast, the incidence of atypical visual behaviors did not differ between the groups. Lower receptive language skills in the ASD-MLV group were predicted by greater incidence of atypical auditory behaviors. Exploratory analyses revealed a significant negative correlation between the amount of atypical auditory behaviors and the amplitude of neural response to deviants. Future work is needed to elucidate whether the relationship between atypical auditory behaviors and receptive language impairments in ASD-MLV individuals results from disruptions in the brain mechanisms involved in auditory processing. LAY SUMMARY: Minimally and low verbal children and adolescents with autism (ASD-MLV) displayed more atypical auditory behaviors (e.g., ear covering and humming) than verbally fluent participants with ASD. In ASD-MLV participants, time spent exhibiting such behaviors was associated with receptive vocabulary deficits and weaker neural responses to changes in sound loudness. Findings suggest that individuals with ASD with both severe expressive and receptive language impairments process sounds differently.