Sensory Abnormalities and Earlier P3a in Adults with Autism Spectrum Disorder

Background:

Perceptual disturbance is among the essential features of autism spectrum disorder (ASD) with hyper- or hyporeactivity in the same individual across different sensory modalities. Despite some data in children with ASD, little is known about the sensory profile of adults with ASD. Most of current studies assess sensory symptoms by self-report or parent-report questionnaire, rather than an objective method. Although some studies used event-related potentials (ERP) to demonstrate the sensory abnormality in children with ASD, whether the ERP abnormalities persist into adulthood remains inconclusive.

Objectives:

This study investigated perceptual disturbances in young adults with ASD by self-report on sensory measure as well as ERPs, including P50, Mismatch Negativity (MMN), and P3a.

Methods:

Thirty-seven participants, aged 15 to 30, with a clinical diagnosis of either high-functioning autism or Asperger’s disorder and 35 typically developing controls (TD), aged 15 to 27, were assessed with ERPs and completed the self-administered questionnaires of the Chinese versions of the Adolescent/Adult Sensory Profile, Social Responsiveness Scale, and Autism Questionnaire. Three kinds of ERPs, P50, MMN, and P3a component using frequency and duration paradigms, were compared between the ASD and TD groups. The clinical correlates of ERPs parameters were also examined.

Results:

Compared to TD, young adults with ASD showed greater sensory symptoms on subscales of low registration, sensory sensitivity, and sensory avoidance, but less sensation seeking. Regarding the parameters of ERPs, young adults with ASD displayed shorter dP3a peak latency but similar amplitude on P50, MMN and P3a. Notably, there were different correlation patterns between the ASD and TD groups on sensory profiles, autistic symptoms and ERP parameters. The patterns of clinical correlates for ERP responses differed between the ASD and TD groups. Both P3a paradigms showed correlations with several ASD-related symptoms, such as social awareness deficits and stereotyped behaviors, as well as sensory symptoms such as sensory avoiding.

Conclusions:

Our findings of sensory symptoms and P3a latency deviations in ASD and their associations with clinical symptoms provide evidence to support perceptual disturbance in young adults with ASD and the clinical correlates of ERP responses. Pre-attentive sensory gating and novelty detection seem not different from TD in adulthood. These findings need further validation.