Anatomical and Functional Connectivity in Autism Spectrum Disorders
There is growing consensus that atypical cognitive and behavioral function in ASD is associated with abnormalities in brain network organization. This chapter reviews the anatomical and functional evidence on connectivity in ASD from diffusion tensor imaging (DTI) and functional connectivity MRI (FCMRI) studies. DTI studies overwhelmingly present evidence of white matter compromise across virtually all major fiber tracts of the brain in children and adults with ASD (although infants show a different pattern of early white matter development). While many FCMRI studies have found underconnectivity in ASD, others have reported diffuse overconnectivity. Both types of findings may reflect a reduced differentiation of networks in ASD. However, the field has been hampered by lack of methodological awareness, which is necessary to avoid misleading generalizations. Functional and anatomical connectivity have often been studied in isolation in the past, but a combination of imaging techniques will be necessary for a more comprehensive understanding of the impact of abnormal connectivity on cognitive processing in ASD.
KeywordsAutism Spectrum Disorder Autism Spectrum Disorder Fractional Anisotropy Diffusion Tensor Imaging Functional Connectivity
Work on this chapter was supported by the National Institutes of Health (R01-MH081023, R01-DC006155).
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