Authors:

MOHR, B., Ludlow, A., Whitmore, A., GARAGNANI, M. & PULVERMULLER, F.

Reference:

Year of publication:

2010

CBU number:

7133

Abstract:

Sensory symptoms are characteristic among individuals with autism spectrum disorders (ASD) and have been thought to relate to both language alterations and problems in social interactions. These sensory deviations appear to affect auditory processing, leading to hyper- or hyposensitivity to sounds and speech. 12 high functioning children (mean age 13.1 years) with a diagnosis of autism spectrum disorders and 12 typically developing children (mean age 13.4 years) participated in an auditory oddball task using speech sounds. Both groups were matched for verbal and nonverbal IQ and for handedness. In a mismatch negativity (MMN) paradigm, responses to changes in loudness were compared to those of stimulus length and changes in frequency. We found significantly reduced MMN responses to loudness deviants in ASD children compared to typically developing children. In contrast, other deviant stimuli produced similar MMNs in both groups. Further analyses showed that the stimulus-specific MMN difference in ASD children was due to deviant-elicited ERPs whereas standard responses were similar for both populations. Our data suggest hyposensitivity in detecting auditory changes in speech sounds in children with ASD, as reflected in a reduced MMN for deviant sounds of decreased loudness. We discuss the possible role of the MMN as a neurophysiological marker of change-type specific sensitivity in children with autism spectrum disorders.