Auditory Spatial Attention and Symptom Severity in Children with Autism Spectrum Disorder

Background: One of the earliest observable impairments in autism spectrum disorder (ASD) is a failure to orient to speech and other social stimuli. Auditory spatial attention, a key component of orienting to sounds in the environment, is likely to play a critical role in the early development of social communication skills and social functioning throughout the lifespan. In fact, auditory spatial attention has already been shown to be impaired in adults with ASD, but has not yet been characterized in children with ASD or linked to core ASD symptoms.

Objectives: We aimed to characterize auditory spatial attention in children with ASD and neurotypical peers. Our secondary goal was to explore the relationship between auditory spatial attention abilities and core behavioral symptoms of ASD.

Methods: Sixteen rigorously diagnosed (ADOS, ADI-R) children and adolescents (ages 10-17) with ASD and 18 neurotypical age- and IQ-matched peers participated in this study. In the spatial attention task, target and distractor sounds were played randomly in rapid succession from six speakers in a free-field array. Subjects attended to a speaker directly in front of them, and were instructed to respond to target sounds at the attended location while ignoring sounds from adjacent speaker locations. The spatial attention gradient was characterized using the proportion of subjects’ responses to target sounds at attended vs. adjacent speakers, using d’ as a measure of spatial attention. Well validated parent report measures provided information regarding current ASD symptom severity, as well as a characterization of attention deficit hyperactivity disorder (ADHD) symptoms.

Results: Children with ASD had significantly more diffuse auditory spatial attention compared to neurotypical children (F=8.94, p=.005, partial eta-squared =.22). While both groups had equal accuracy in detecting the target sound, children in the ASD group had significantly increased responding to sounds at adjacent non-target locations. Due to the magnitude of the group difference in spatial attention, correlational analyses were conducted separately by group. Within the ASD group, more diffuse auditory spatial attention was significantly associated with greater ASD symptom severity (r=.675, p=.01). In contrast, diffusion of auditory spatial attention was not related to ADHD attention symptom severity (r=.310, p=.33) or age (r=.311, p=.24). Spatial attention was not significantly associated with ASD symptoms, ADHD symptoms, or age in the neurotypical group.

Conclusions: Auditory spatial attention was significantly more diffuse in children with ASD than their neurotypical peers, primarily due to difficulty ignoring nearby competing sounds. In the children with ASD, those with more diffuse auditory spatial attention had greater ASD symptom severity.  Importantly, spatial attention abilities were not significantly related to ADHD attention symptoms in this population, providing further evidence that auditory spatial attention abilities may be uniquely associated with the development of ASD symptoms. It will be crucial for future research to examine the early development of auditory spatial attention and its role in the development of social communication differences in ASD.