Atypical brain responses to illusory auditory pitch in children with autism

Atypical auditory perception is widely reported in association with autism. In the current study, we recorded the brain responses of children with autism to dichotic pitch stimuli, in which inter-aural timing differences result in the illusory perception of a pitch sound spatially segregated from a carrier white noise. MEG responses of ten 8- to 12-year-old children with autism and ten age-matched typically developing children were recorded as they viewed a movie while ignoring the auditory stimuli. MEG data were projected onto sources in bilateral auditory cortex and event-related fields for a control stimulus (no inter-aural timing difference) were subtracted from responses to the illusory pitch stimulus. Children with autism evidenced a component in this difference waveform at around 50 ms, which was not present in the control group. The results demonstrate that individuals with autism are sensitive to inter-aural timing differences and provide further evidence for atypical auditory processing in at least some individuals on the autism spectrum.