Current models of autism spectrum disorder suggest alterations in integrated brain functioning at both cognitive and anatomical levels. Large-scale brain abnormalities in autism include increased brain volumes in young affected individuals that appear to be mainly caused by increases in white matter (which forms the connections between different brain regions). This suggests that altered connectivity among brain networks, rather than changes in function in any single cortical region, may form the anatomical basis of the cognitive impairments in social, language and communication functions found in ASD. This proposal employs electroencephalographic (EEG) coherence methods to investigate functional connectivity in autism spectrum disorder. EEG coherence quantifies the degree of synchronization between different parts of the brain, and is believed to reflect the functional connections between brain regions. Prior work applying EEG coherence methods to adults with autism in the resting state has demonstrated, for example, robust patterns of decreased connectivity, primarily in long distance connections involving the frontal lobes. This proposal expands on prior work demonstrating resting state differences, and it investigates functional connectivity in a visual perception task. Further understanding of the dynamic functional processes that occur in resting and controlled cognitive states will inform understanding of altered cortical physiology in ASD. What this means for people with autism: Information regarding specific patterns of impairments in functional connections between brain regions may lead to knowledge and methodologies that have the potential to advance understanding of the causes, diagnosis and treatment of autism.