What's in a voice? Prosody as a test case for the Theory of Mind account of autism.

The human voice conveys a variety of information about people's feelings, emotions and mental states. Some of this information relies on sophisticated Theory of Mind (ToM) skills, whilst others are simpler and do not require ToM. This variety provides an interesting test case for the ToM account of autism, which would predict greater impairment as ToM requirements increase. In this paper, we draw on psychological and pragmatic theories to classify vocal cues according to the amount of mindreading required to identify them. Children with a high functioning Autism Spectrum Disorder and matched controls were tested in three experiments where the speakers' state had to be extracted from their vocalizations. Although our results confirm that people with autism have subtle difficulties dealing with vocal cues, they show a pattern of performance that is inconsistent with the view that atypical recognition of vocal cues is caused by impaired ToM.