Impairments in communication and social interaction are defining characteristics of individuals with autism spectrum disorders. Even when other aspects of their language function improve, autistic people often continue to have problems with an aspect of speech known as prosody. Prosody contributes significantly to the ‘personal' information that is conveyed by speech and enables individuals to participate in the construction of a socially meaningful and effective conversation. The limited data on perception of prosody in autism suggests the greatest impairment is in the domain of prosody's emotional-pragmatic functions (when a person's manner of speech conveys that they feel angry, for example) rather than its grammatical functions (when a person's manner of speech expresses a question rather than a statement, for example). Emotional prosody will be the focus of the current investigation. The investigators propose that difficulties with prosody for individuals with autism spectrum disorders may be related to underlying abnormalities in the connectivity among brain regions. Behavioral testing and magnetic resonance imaging will be used to address this under-researched issue and its neurobiology in a systematic and detailed fashion. Brand new imaging techniques will allow the investigators to assess the autistic individuals' brain responses to emotional speech at the same time that they assess the connectivity among important brain regions. The researchers will also compare the data from the autistic subjects to that of some of their unaffected siblings and to unrelated control subjects. This feature of the project offers the possibility of preliminarily identifying ‘markers' in the brain that may be different between families and could help guide future studies. What this means for people with autism: When capacity for prosody is abnormal, this has the potential for impeding the social interaction and integration of such individuals. These brain imaging results could provide important data on mechanisms underlying fundamental difficulties in autism and help explain why some individuals may be more impaired than others.