Auditory stream segregation in children with Asperger syndrome

Abstract

Individuals with Asperger syndrome (AS) often have difficulties in perceiving speech in noisy environments. The present study investigated whether this might be explained by deficient auditory stream segregation ability, that is, by a more basic difficulty in separating simultaneous sound sources from each other. To this end, auditory event-related brain potentials were recorded from a group of school-aged children with AS and a group of age-matched controls using a paradigm specifically developed for studying stream segregation. Differences in the amplitudes of ERP components were found between groups only in the stream segregation conditions and not for simple feature discrimination. The results indicated that children with AS have difficulties in segregating concurrent sound streams, which ultimately may contribute to the difficulties in speech-in-noise perception.

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

“…However, in two other electrophysiological studies intensity processing of pure tones was deficient (Bruneau et al, 1999(Bruneau et al, , 2003. These different outcomes could probably be explained by differences in participant selection: Bruneau et al (1999) and Bruneau et al (2003) studied a group of very young mentally retarded children with autism, whereas the other studies either tested a group of children with Asperger syndrome (Lepistö et al, 2009) or a group of children with autism or ASD with mixed IQs (Khalfa et al, 2004;Jones et al, 2009).…”

“…One behavioural study found enhanced intensity perception (Khalfa et al, 2004) and one study found intact, but not enhanced, intensity discrimination of pure tones (Jones et al, 2009). Electrophysiological intensity processing of pure tones was intact in one study when stream segregation was not required (Lepistö et al, 2009). However, in two other electrophysiological studies intensity processing of pure tones was deficient (Bruneau et al, 1999(Bruneau et al, , 2003.…”

“…The Asperger group showed a diminished MMN in the segregated condition; however, intensity discrimination was intact when stream segregation was not required. Thus, children with Asperger syndrome appear to be less efficient in auditory stream segregation, which, as proposed by Lepistö et al (2009), might have implications for the perception of speech in noisy environments. Initial auditory cortical processing was intact in these children as reflected by a normal P1 and P2 response.…”

“…The superior temporal gyrus, the superior temporal sulcus, and in particular the left posterior superior temporal sulcus, are important for auditory processing and speech perception (i.e., analyzing rapidly changing auditory input and deriving meaning from it) (Redcay, 2008;Scott & Johnsrude, 2003). Lepistö et al (2009) used pure tones of varying intensities to investigate auditory stream segregation in Asperger syndrome. The researchers used three different conditions: an oddball condition, a segregated and an integrated condition.…”

The Relationship Between Auditory Processing and Restricted, Repetitive Behaviors in Adults with Autism Spectrum Disorders

“…Despite the fact that previous research shows that people with ASD have increased sensitivity (Frith and Baron-Cohen, 1987) and reduced tolerance (hyperacusis) (Khalfa et al, 2004;Rosenhall et al, 1999) to loudness, intensity discrimination ability appears to be intact in adults and adolescents with ASD (Bonnel et al, 2010;. Of note, one study used pure tones of varying intensities (the 'oddball' paradigm) to investigate auditory stream segregation (mismatch negativity (MMN) responses) in children with ASD (Lepistö et al, 2009). Intensity discrimination was intact in ASD when stream segregation (to separate sounds that come from different sources) was not required.…”