Atypical sound discrimination in children with ASD as indicated by cortical ERPs

• Published in: Journal of neurodevelopmental disorders 2017-04, Vol.9 (1), p.13-13, Article 13
• Main Authors: Bidet-Caulet, Aurélie, Latinus, Marianne, Roux, Sylvie, Malvy, Joëlle, Bonnet-Brilhault, Frédérique, Bruneau, Nicole
• Format: Article
• Language: English
• Subjects: Age; Auditory; Auditory perception; Autism; Child & adolescent psychiatry; Children; Children & youth; Cortex; Development; EEG; Electrodes; Event-related potentials; FTPV; Information processing; Life Sciences; NMR; Nuclear magnetic resonance; Sound; Specialization; Spectrum analysis; Speech; Speech perception; Standard deviation; Statistical analysis; Superior temporal sulcus; Voice
• ISSN: 1866-1947; 1866-1955
• DOI: 10.1186/s11689-017-9194-9

Individuals with autism spectrum disorder (ASD) show a relative indifference to the human voice. Accordingly, and contrarily to their typically developed peers, adults with autism do not show a preferential response to voices in the superior temporal sulcus; this lack of voice-specific response was previously linked to atypical processing of voices. In electroencephalography, a slow event-related potential (ERP) called the fronto-temporal positivity to voice (FTPV) is larger for vocal than for non-vocal sounds, resulting in a voice-sensitive response over right fronto-temporal sites. Here, we investigated the neurophysiological correlates of voice perception in children with and without ASD. Sixteen children with autism and 16 age-matched typically developing children heard vocal (speech and non-speech) and non-vocal sounds while their electroencephalographic activity was recorded; overall IQ was smaller in the group of children with ASD. ERP amplitudes were compared using non-parametric statistical tests at each electrode and in successive 20-ms time windows. Within each group, differences between conditions were assessed using a non-parametric Quade test between 0 and 400 ms post-stimulus. Inter-group comparisons of ERP amplitudes were performed using non-paired Kruskal-Wallis tests between 140 and 180 ms post-stimulus. Typically developing children showed the classical voice-sensitive response over right fronto-temporal electrodes, for both speech and non-speech vocal sounds. Children with ASD did not show a preferential response to vocal sounds. Inter-group analysis showed no difference in the processing of vocal sounds, both speech and non-speech, but significant differences in the processing of non-vocal sounds over right fronto-temporal sites. Our results demonstrate a lack of voice-preferential response in children with autism spectrum disorders. In contrast to observations in adults with ASD, the lack of voice-preferential response was attributed to an atypical response to non-vocal sounds, which was overall more similar to the event-related potentials evoked by vocal sounds in both groups. This result suggests atypical maturation processes in ASD impeding the specialization of temporal regions in voice processing.