White matter correlates of sensory processing in autism spectrum disorders.
Autism spectrum disorder (ASD) has been characterized by atypical socio-communicative behavior, sensorimotor impairment and abnormal neurodevelopmental trajectories. DTI has been used to determine the presence and nature of abnormality in white matter integrity that may contribute to the behavioral phenomena that characterize ASD. Although atypical patterns of sensory responding in ASD are well documented in the behavioral literature, much less is known about the neural networks associated with aberrant sensory processing. To address the roles of basic sensory, sensory association and early attentional processes in sensory responsiveness in ASD, our investigation focused on five white matter fiber tracts known to be involved in these various stages of sensory processing: superior corona radiata, centrum semiovale, inferior longitudinal fasciculus, posterior limb of the internal capsule, and splenium. We acquired high angular resolution diffusion images from 32 children with ASD and 26 typically developing children between the ages of 5 and 8. We also administered sensory assessments to examine brain-behavior relationships between white matter integrity and sensory variables. Our findings suggest a modulatory role of the inferior longitudinal fasciculus and splenium in atypical sensorimotor and early attention processes in ASD. Increased tactile defensiveness was found to be related to reduced fractional anisotropy in the inferior longitudinal fasciculus, which may reflect an aberrant connection between limbic structures in the temporal lobe and the inferior parietal cortex. Our findings also corroborate the modulatory role of the splenium in attentional orienting, but suggest the possibility of a more diffuse or separable network for social orienting in ASD. Future investigation should consider the use of whole brain analyses for a more robust assessment of white matter microstructure.
Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA.
Jennifer R
JR
Pryweller
Department of Clinical and Social Sciences in Psychology, University of Rochester, Rochester, NY, USA.
Kimberly B
KB
Schauder
Vanderbilt University Institute of Imaging Science, Nashville, TN, USA ; Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, USA ; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA.
Adam W
AW
Anderson
Vanderbilt University Department of Psychiatry, Nashville, TN, USA.
Jessica L
JL
Heacock
Yale University Child Study Center, Yale University, New Haven, CT, USA.
Jennifer H
JH
Foss-Feig
Vanderbilt University Department of Psychiatry, Nashville, TN, USA ; Vanderbilt Kennedy Center, Nashville, TN, USA ; Vanderbilt University Department of Pediatrics, Nashville, TN, USA.
Cassandra R
CR
Newsom
Vanderbilt University Department of Psychiatry, Nashville, TN, USA ; Vanderbilt Kennedy Center, Nashville, TN, USA ; Vanderbilt University Department of Pediatrics, Nashville, TN, USA.
Whitney A
WA
Loring
Vanderbilt University Department of Psychiatry, Nashville, TN, USA ; Vanderbilt Kennedy Center, Nashville, TN, USA.
Carissa J
CJ
Cascio
D001288:Attention / Q000502:physiology; D001921:Brain / Q000473:pathology*; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000473:pathology* / Q000503:physiopathology*; D002675:Child, Preschool; D003337:Corpus Callosum / Q000473:pathology; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D066127:White Matter / Q000473:pathology*