Identifying changes in brain anatomy can be a critical tool in diagnosing and evaluating neurological disorders. In studies of the brain structure of children with autism, it has been shown that the sizes of certain brain regions are increased in volume. However, more detailed information on brain anatomy than simply size will be necessary to understand the differences between autistic and non-autistic brains. In this study, the authors will use new computational tools and imaging techniques to study the structure of the autistic brain in greater detail. They will also examine whether the differences observed correlate with impaired motor skills, a common symptom of autism. To examine the brain structure of autistic children, these researchers will use a computational technique known as large deformation diffeomorphic metric mapping, or LDDMM, to measure not just the size but the shape of particular brain regions. They will also use diffusion tensor imaging to examine the structure of white matter tracts, which carry neural information between brain regions. These structural analyses will provide much more detail than simple measurements of the area or volume brain regions. Next, they will collect behavioral data on motor coordination from their subjects, and determine whether changes in the shape, size, or white matter tracts of any particular brain regions are associated with particular motor difficulties. More accurate identification of changes to brain anatomy in autism may provide new and powerful tools for the early diagnosis and evaluation of autism.