TRACT-BASED SPATIAL STATISTICS FROM DIFFUSION-WEIGHTED MRI REVEAL SPECIFIC WHITE MATTER CORRELATES OF GLOBAL MOTION SENSITIVITY IN TYPICALLY DEVELOPING CHILDREN

摘要

Impaired sensitivity to global motion, but not to global form, has been found as a signature in a range of neurodevelopmental disorders, often associated with spatial and attention deficits and poor mathematical skills Previously we reported (Atkinson et al, VSS 2014) individual differences in global motion in typically developing children, high sensitivity being associated with a relatively enlarged surface area of the parietal lobe (especially around the intraparietal sulcus) and reduced occipital area. Here we explore whether global motion sensitivity is also associated with organization in white matter fibre tracts. We analysed fractional anisotropy (FA) within major fibre tracts defined by tract-based spatial statistics (TBSS) in 125 typically developing children from the PLING study (Pediatric Longitudinal Imaging Neurocognition and Genetics). The superior longitudinal fasciculus (SLF) was treated as the main candidate tract, given its connections to parietal areas previously associated with global motion performance. We found higher global motion sensitivity was related to asymmetry in the SLF, with higher FA in the right SLF showing a positive association (p=0.003), and the left a negative association (p=0.02). This relation was not found for overall FA or for other specific tracts, and was not found for global form. In contrast we found that the parietal surface area expansion associated with motion performance was stronger in the left than in the right hemisphere. We conclude that (a) developmental variation in global motion sensitivity is linked to local white matter organization in SLF, as well as to regional differences in parietal area ; (b) a complex pattern of hemispheric asymmetry in both fibre tracts and cortical area is associated with the phenotype of high global motion sensitivity. These finding provide pointers for the neuroanatomical investigation of the visual correlates of neurodevelopmental disabilities.