Auditory hyper-reactivity and gating across development in autism

Poster Session E - Monday, April 15, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Ala Seif^1,2,3 (aseif5@uwo.ca), Renee Guerville^1,2, Mohammad Rajab^1,2, Kristina Schaaf^1,2, Susanne Schmid^1,3, Ryan A. Stevenson^1,2; ¹Western Institute of Neuroscience, University of Western Ontario, ²Department of Psychology, University of Western Ontario, ³Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario

Background: Autism has been historically defined by difficulties in social communication, restricted and repeated behaviors and interests, and motor stereotypies. Autistic people also exhibit sensory processing disruptions that have been shown to contribute to these core symptoms. Sensory issues, such as hyper-reactivity and sensory gating, are characterized clinically by parent questionnaires. However, behavioural measures of them are available in laboratory settings. One promising method to study sensory issues in autism is the acoustic startle response. The acoustic startle response is a reflexive muscular contraction to a sudden loud sound. It is a measure of acoustic reactivity. In addition, the modulation of the startle response by a quieter pre-pulse that precedes the louder pulse is referred to as pre-pulse inhibition which is a measure of sensory gating. Objective: The objective of this study is to use an acoustic startle paradigm to examine sensory reactivity and sensory gating differences in autism across development. Methods: Autistic (n=26) and non-autistic (n=43) children and adults completed an auditory startle task to assess the acoustic startle response and pre-pulse inhibition. Results: There was a main effect of reactivity F(1, 61)= 5.37 p=0.024 and no interaction with age. There was no group difference in pre-pulse inhibition. Conclusion: Autistic participants presented with hyper-reactivity as assessed by the startle response. However, they did not have any difficulties in sensory gating as measured by pre-pulse inhibition. The neural pathways involved in both theses processes are well-established. Therefore, this study narrows down the possible pathways involved with sensory disruptions in autism.

Topic Area: PERCEPTION & ACTION: Audition