| Abstrakt: |
Objective: The aim of this study is to investigate the structural connectivity in children with mathematical-learning-disability (dyscalculia) and normally-developing-peers. Methods: Firstly, we tested 1944 third-grade students (7-9,5 years) in elementary schools with Mathematics and Arithmetic- Performance tests, and Raven Progressive Matrices test for fluid intelligence. Regarding screening results, children with normalintelligence were assigned to dyscalculia (lowest 25th-percentile) and typically developing (between 35th-75th-percentiles) groups. Secondly, determined children were tested two-years later with mathematics-tests and Weschler Intelligence Scale for Children, and evaluated by child-psychiatrists. After co-morbidities were eliminated, dyscalculia and typically developing groups were precisely identified. Then, we invited children for MRI-scan and required them to practice in mock-scanner before real MRI-scanning. Lastly, we acquired DTI (Diffusion-Tensor-Imaging) data via Siemens 3Tesla-scanner using 16-channel-head-coil. Images were sampled along 60-different-encoding-directions. There were 70-images in total, and b-value for the first 10-images was 0s/mm2 and b=700s/mm2 for other 60-images for each of 60- directions. The thicknes of transversal-slices (74slices) was 1.55mm and parallel to Anterior-to-Posterior-plane. TR:9.506s, TE:85ms, FOV:198mm, voxel size 1.5×1.5×1.6 mm. Duration was about 11 min for each child and children watched cartoons which they wanted during scanning. We obtained 11 dyscalculics' and 16 control children' usable data. Results: We used FSL-software for DTI analyses. Initially, head movements and eddy-currents were corrected, and then fractional- anisotropy (FA) maps of participants were created. After that, TBSS (Tract-Based-Spatial-Statistics) analysis was performed on FA maps to investigate groups' whole-brain voxelwise comparisons with TFCE (Threshold-free-cluster-enhancement) method (Smith et al., 2006)*. In Controls>Dyscalculics contrast, FA values for some particular white matter connections such that left-inferior fronto-occipital fasciculus, left-right anterior- thalamic-radiations and left cortico-spinal tract were significantly higher in typically developing children than dyscalculics (p<.05, FWE-corrected). In Dyscalculics>Controls contrast, FA values in dyscalculics were not significantly different from controls (p>.05, FWE-corrected). Conclusion: The findings suggest that low white matter integrity and/or structural connectivity especially in left brain areas might be related to mathematical-learning-disability in children. This study was supported by The-Scientific-and-Technological- Research-Council-of-Turkey under the-project-code-214S069. [ABSTRACT FROM AUTHOR] |
