Perception and Production in Autism Spectrum Disorder

Abstract

<p>Many behavioural theories describe Autism Spectrum Disorder (ASD) as having roots as a social disorder. However, our research adds to previous studies showing that those with ASD with normal intelligence have perceptual problems that affect their social functioning. We report that those with ASD perform worse than controls in all of our speech tasks that measure the ability to filter speech in noise, specialization for native speech sound categories, and audio-visual integration of speech sounds. Those with ASD also performed worse on tasks measuring specialization for native musical meters, but not on tasks measuring absolute pitch or knowledge of tonal harmony. This research provides some explanation for why perceptual areas that develop early instead of late are most impaired in ASD, which can have implications for remediation. Besides perceptual problems, we found in other research that those with ASD have abnormal prosody, which varies according to language ability. We report that those with Autism Moderate Language Functioning (A-moderateL) use a restricted pitch range relative to those with Autism High Language Functioning (A-highL) and controls, whereas those with A-highL use a larger pitch range relative to those with A-moderateL and controls. We also found that A-moderateL speakers and controls, but not A-highL speakers vary acoustic features to mark words representing focus relative to topic. This research is important because identifying different ASD language subgroups might lead to more appropriate speech and language therapy.</p>