Project Title: Utah Autism Project Principal Investigator: Andrew Alexander, PhD The main objective of the project is to use longitudinal MR imaging to measure changes in the brain of both children and young adults with high functioning autism and compare them with matched control subjects. The imaging measures will be compared with the type and level of disability. The subject recruitment, characterization and imaging are being performed at the University of Utah in the laboratories of Janet Lainhart and William McMahon. Through a subcontract, we are responsible for the analysis of the diffusion tensor image data that is being collected at Utah. The advanced diffusion tensor imaging (DTI) analysis methods that are being developed in Project 95 will be applied to this data. The image analysis includes the calculation of quantitative diffusion tensor measurement maps (mean diffusivity, anisotropy and orientation). We are applying advanced image segmentation approaches including white matter tractography to investigate specific anatomical connections. We recently completed an analysis of DTI properties in the corpus callosum and found that the diffusion anisotropy was decreased and mean diffusivity was increased in autism relative to controls. We are also investigating the diffusion tensor properties of several brain regions including the temporal stem and superior temporal gyrus of subjects with autism. These areas have shown differences in several studies of brain morphometry and functional brain imaging. Ultimately, we will compare these DTI measures to behavioral measures of language and social interaction skills, which are affected in autism. In addition to performing comparisons in a cross-sectional design, the subjects are being brought back 2.5 years after their first imaging session to measure longitudinal changes. The measurements of the second time points will commence in 2006.

Copyright © 2006 Waisman Center Last updated 2/2/2006 by rowley@waisman.wisc.edu Waisman Center ~ 1500 Highland Avenue ~ Madison, WI 53705-2280 Telephone: (608) 263-5776 or (608) 263-5910 ~ TDD: (608) 263-0802 FAX: (608) 263-0529 ~ webmaster@waisman.wisc.edu ~ www.waisman.wisc.edu