Poster A10, Tuesday, August 20, 2019, 10:15 am – 12:00 pm, Restaurant Hall
Auditory window of integration relates to language disorder: An event-related potentials study of children with autism spectrum disorder
Elaine Kwok1, Janis Oram Cardy1;1Communication Sciences and Disorders, Western University, Canada
Introduction: Auditory perception results from neural integration of acoustic elements over a brief timeframe, termed the auditory window of integration (AWI) (Bregman, 1990). As children age, the AWI becomes smaller, allowing for more refined perception of rapidly changing auditory stimuli (including speech). An immature (larger) AWI has been reported in individuals with developmental language disorder (McArthur & Bishop, 2004). Few studies have explored the relation of AWI to language disorder associated with autism spectrum disorder (ASD). In older children and adolescents with ASD, those with co-occurring language impairment (ASD+LI) are likely to have a longer AWI compared to peers with ASD without language disorder (ASD–LI) (Oram Cardy, Flagg, Roberts & Roberts, 2008). This study explored the AWI of school-age children with ASD using electroencephalography. Methods: Participants were 6–11 year olds with ASD and at least average WASI Performance IQ. Children with ASD+LI (n=7) scored below –1.25SD on a standardized oral language measure, the CELF-4, whereas children with ASD–LI (n=12) scored within normal limits. Auditory evoked potentials (AEPs) were recorded using a 128-channel EGI system while the following four blocks of auditory stimuli (225 trials each) were presented: Single pure tone (One Tone); Two Tones separated by 100ms (TT100); Two Tones separated by 200ms (TT200); Two Tones separated by 400ms (TT400). For each participant, we compared a segment of 0–400ms AEP response from each of the TT conditions to the One Tone condition using intraclass correlation coefficient (ICC), an index of waveform similarity (Bishop & McArthur 2004). For the TT400 condition, only the AEP response to the first of the two tones was included in this comparison, thus generating a reference ICC value. A significantly lower ICC in the TT100 and TT200 conditions relative to this reference ICC would suggest the presence of a response to the second tone. Conversely, a similar ICC would suggest the absence of a second tone response (i.e., the two tones fall within the AWI and may be processed as one tone). Results: Children with ASD–LI and ASD+LI did not significantly differ in age or Performance IQ (p ≥ 0.541), but those with ASD+LI had significantly weaker oral language (p < 0.001). For the group with ASD–LI, the ICC values from both the TT100 (M = 0.78, SD = 0.39) and TT200 (M = 0.77, SD = 0.35) conditions were significantly lower than that of TT400 (M =0.94, SD = 0.32), p < 0.05, suggesting a second tone AEP response was present in both conditions. By contrast, for the group with ASD+LI, only the ICC value from the TT200 condition (M = 0.92, SD = 0.33) was significantly lower than the TT400 condition (M = 1.09, SD = 0.36), p < 0.05, suggesting that a second tone AEP response was only present in the TT200 condition. Conclusions: Results suggested that the AWI was less than 100ms in children with ASD–LI and between 100ms and 200ms in children with ASD+LI. Immature AWI may be related to language disorder associated with ASD.
Themes: Disorders: Developmental, Perception: Auditory
Method: Electrophysiology (MEG/EEG/ECOG)