Magnetoencephalography identifies rapid temporal processing deficit in autism and language impairment

Abstract

Deficient rapid temporal processing may contribute to impaired language development by interfering with the processing of brief acoustic transitions crucial for speech perception. Using magnetoencephalography, evoked neural activity (M50, M100) to two 40 ms tones passively presented in rapid succession was recorded in 10 neurologically normal adults and 40 8-17-year-olds with autism, specific language impairment, Asperger syndrome or typical development. While 80% of study participants with intact language (Asperger syndrome, typical development, adults) showed identifiable responses to the second tone, which presented rapid temporal processing demands, 65% of study participants with impaired language (autism, specific language impairment) did not, despite having shown identifiable responses to the first tone. Rapid temporal processing impairments may be fundamentally associated with impairments in language rather than autism spectrum disorder.

A review of behavioural and electrophysiological studies on auditory processing and speech perception in autism spectrum disorders

“…Whitehouse and Bishop (2008), on the other hand, found a deficit in initial auditory cortical processing in children with autism. The MMN of phoneme discrimination was intact, which differs from the findings of Oram Cardy, Flagg, Roberts, Brian, et al (2005), Oram Cardy, Flagg, Roberts, and Roberts (2005) and Kasai et al (2005).…”

“…The electrophysiological findings, however, are not unequivocal as some ERP or ERF studies have also shown deficient pure tone pitch processing and discrimination in ASD (Jansson-Verkasalo et al, 2003, 2005Oram Cardy, Flagg, Roberts, Brian, et al, 2005;Tecchio et al, 2003).…”

“…Duration discrimination was also considered in this study, but no abnormalities were found when discriminating duration changes in vowels. A study by Oram Cardy, Flagg, Roberts, Brian, et al (2005) and Oram Cardy, Flagg, Roberts, and Roberts (2005) with children with autism also found a delayed MMF for phonetic changes. In this same study pitch discrimination of vowels also resulted in delayed MMF, which is inconsistent with previously described studies that investigated pitch discrimination of vowels.…”

“…Oram Cardy, Flagg, Roberts, Brian, et al (2005), Oram Cardy, Flagg, Roberts, and Roberts (2005) and Oram Cardy, Flagg, Roberts, and Roberts (2008) investigated language and auditory processing in autistic children versus language-impaired children (SLI). In the first study, pairs of 1 kHz tones were separated by a 150 ms silent gap (Oram Cardy, Flagg, Roberts, Brian, et al, 2005;.…”

“…In the first study, pairs of 1 kHz tones were separated by a 150 ms silent gap (Oram Cardy, Flagg, Roberts, Brian, et al, 2005;. The ERF responses of four groups were compared: an autism group, an Asperger group, a language impaired group and a typically developing group.…”