Even individuals with ASD who develop fluent use of spoken language often sustain problems with prosody – understanding the more subtle aspects of speech like rhythm, stress, and intonation. Deficits in prosody can affect receptive as well as expressive language and can make it difficult for people with ASD to appreciate `personal' and socially meaningful information conveyed by speech communication. A currently popular view is that these deficits in ASD may involve abnormalities in long-range neural connectivity between disparate brain regions. In this study, the researchers will measure brain activity with functional magnetic resonance imaging (fMRI) in high-functioning autistic individuals (HFA), their siblings, and typically developing control subjects as they perform behavioral tasks involving prosody. By using this approach, researchers can assess differences in brain structure, functional connectivity and white matter tract integrity in brain networks engaged by the subjects during prosodic communication. An overarching goal of this two-year brain imaging project is to determine whether abnormal connections in the brain may account for some of the communication impairments in autism, particularly those involved in the understanding of verbally expressed emotion between individuals. Results of this project may also enrich our understanding of how emotion and other personal aspects of verbal communication are understood by typical individuals and clarify mechanisms by which these processes can be disrupted in the human brain.