Speech perception and involuntary orientation to speech stimuli in individuals with Autism Spectrum Disorder

Individuals with autism spectrum disorder (ASD) are known to have language and social deficits, yet the exact reasons for theses deficits are not fully understood. Language develops from exposure. Deficits in perception of speech can have devastating effects on an individual’s ability to reproduce language and communicate effectively. The MMN and P300 ERP components can be used to assess sound discrimination and orientation, respectively. In previous work, individuals with ASD have shown little difference in MMN amplitudes to pure and complex tones but diminished P300 amplitudes for speech sounds, suggesting they can hear differences in speech components but cannot attend to them. This study uses EEG to look at auditory perception and involuntary attentional orientation. Using an oddball paradigm, the subjects were presented with four distinct auditory conditions: pure tones, complex tones, synthetic speech, and human speech. The MMN and P300 for each individual with ASD was compared to those of typically developing (TD) individuals. Differences, in MMN for pure tone and in P300 for complex tone, synthetic speech, and human speech, were found between ASD and TD participants. The distinct speech conditions were included to allow a deeper comparison and understanding of speech perception and involuntary attentional orientation in individuals with ASD