Poster B41, Thursday, August 16, 3:05 – 4:50 pm, Room 2000AB

Receptive but not expressive language relates to age-equivalent of auditory event-related potentials in children with autism spectrum disorder

Elaine Kwok1, Edwin Dovigi2, Janis Oram Cardy1;1University of Western Ontario, 2Rush University Medical College

Introduction: One contributing factor to language impairment is proposed to be immature cortical processing of sounds (McArthur & Bishop 2004). Bishop et al. (2011) and Kwok et al. (2018) demonstrated the utility of estimating age-equivalents for auditory event-related potentials (AEP) to study its relation with language ability. To do so, intra-class correlation (ICC) was calculated between a child’s AEP waveform with a range of normative AEP grand averages across different age bins. The normative grand average waveform that yielded the highest ICC, indicating the highest correlation/resemblance with the child’s AEP, was taken as the AEP-age-equivalent (AEP-age) for this child. In previous work, we tested this new index of cortical maturation in children with developmental language disorder (DLD, also known as specific language impairment, SLI). AEP-age not only explained 31% of variance in the language ability in children with DLD, it predicted receptive, but not expressive language ability (Kwok et al., in press). This finding suggests that the maturity of sound perception, as reflected by AEP-age, may support the development of language comprehension, whereas other cognitive processes may influence the development of language production. In children with autism spectrum disorder (ASD), the role of AEP-age across the domains of language has not been explored. This study asked whether AEP-age relates to expressive, receptive or both domains of language. Methods: AEPs in response to 225 trials of a 50ms, 490Hz tone were recorded using a 128-channel EEG system from 98 children aged 7-11 years (typical development: N=78, ASD: N=21). All children scored within the typical range (i.e. >85) on the non-verbal IQ portion of the Wechsler Abbreviated Intelligence Scale and completed the core language subtests of the Clinical Evaluation of Language Fundamentals – 4. Children with typical development scored within normal range on the language test. Based on chronological age, the AEPs from children with typical development were used to create four normative grand averages of 7-, 8-, 9- and 10-years old (N= 20, 21, 22, 15 respectively). Using ICC, the AEP waveforms of each child with ASD were compared to each of these four normative grand averages at frontal electrodes (F3, Fz, F4) to estimate AEP-age. Correlation analysis was used to explore the relation between AEP-age and an expressive language subtest (i.e., Recalling Sentences) and a receptive language subtest (i.e. Concepts and Following Directions). Results: Children with ASD had an average age of 9.1 years (SD = 1.6), non-verbal IQ of 109 (SD = 18) and language standard score of 91 (SD = 17). The average AEP-age was 8.2 years (SD= 1). AEP-age related to receptive language (r = 0.46, p = 0.04) but not expressive language (r = 0.23, p = 0.33). Conclusion: Maturity of auditory cortical processing, estimated using AEP-age, may underlie receptive but not expressive language ability in ASD. Future work should explore the mechanism by which auditory cortical maturation may impact receptive language development.

Topic Area: Language Disorders