Perception of Complex Sounds in Autism: Abnormal Auditory Cortical Processing in Children

OBJECTIVE: The authors have previously described less activation of left speech-related temporal areas in adults with autism when listening to speech-like sounds than in normal adults. Here, they investigated whether this abnormal cortical processing was also present in children with primary autism. METHOD: Regional cerebral blood flow was measured with positron emission tomography after premedication in 11 autistic children and six nonautistic mentally retarded children during rest and while they were listening to speech-like sounds. RESULTS: As with autistic adults, direct comparison between the two groups revealed significantly less activation in the autistic group localized in left speech-related areas. CONCLUSIONS: For the first time to their knowledge, an activation study was performed in children with autism and has confirmed previous results obtained in adults. The abnormal cortical auditory processing observed in both children and adults with autism could be involved in inadequate behavioral responses to sounds and in language impairments characteristic of autism.