This article is part of the Research Topic The developing human brain

Original Research ARTICLE

Front. Hum. Neurosci., 24 November 2009 | doi: 10.3389/neuro.09.051.2009

Neuroanatomical correlates of developmental dyscalculia: combined evidence from morphometry and tractography

1
Department of Psychiatry and Behavioral Sciences, Stanford University, CA, USA
2
Department of Psychology, Stanford University, CA, USA
3
Program in Neuroscience, Stanford University, CA, USA
4
Symbolic Systems Program, Stanford University, CA, USA
Poor mathematical abilities adversely affect academic and career opportunities. The neuroanatomical basis of developmental dyscalculia (DD), a specific learning deficit with prevalence rates exceeding 5%, is poorly understood. We used structural MRI and diffusion tensor imaging (DTI) to examine macro- and micro-structural impairments in 7- to 9-year-old children with DD, compared to a group of typically developing (TD) children matched on age, gender, intelligence, reading abilities and working memory capacity. Voxel-based morphometry (VBM) revealed reduced grey matter (GM) bilaterally in superior parietal lobule, intra-parietal sulcus, fusiform gyrus, parahippocampal gyrus and right anterior temporal cortex in children with DD. VBM analysis also showed reduced white matter (WM) volume in right temporal-parietal cortex. DTI revealed reduced fractional anisotropy (FA) in this WM region, pointing to significant right hemisphere micro-structural impairments. Furthermore, FA in this region was correlated with numerical operations but not verbal mathematical reasoning or word reading. Atlas-based tract mapping identified the inferior longitudinal fasciculus, inferior fronto-occipital fasciculus and caudal forceps major as key pathways impaired in DD. DTI tractography suggests that long-range WM projection fibers linking the right fusiform gyrus with temporal-parietal WM are a specific source of vulnerability in DD. Network and classification analysis suggest that DD in children may be characterized by multiple dysfunctional circuits arising from a core WM deficit. Our findings link GM and WM abnormalities in children with DD and they point to macro- and micro-structural abnormalities in right hemisphere temporal-parietal WM, and pathways associated with it, as key neuroanatomical correlates of DD.
Keywords:
mathematical disability, white matter, grey matter, diffusion tensor imaging, voxel-based morphometry, development
Citation:
Rykhlevskaia E, Uddin LQ, Kondos L and Menon V (2009). Neuroanatomical correlates of developmental dyscalculia: combined evidence from morphometry and tractography. Front. Hum. Neurosci. 3:51. doi: 10.3389/neuro.09.051.2009
Received:
01 September 2009;
 Paper pending published:
05 October 2009;
Accepted:
02 November 2009;
 Published online:
24 November 2009.

Edited by:

Silvia A. Bunge, University of California Berkeley, USA

Reviewed by:

Roland Grabner, Swiss Federal Institute of Technology Zurich, Switzerland
Susan M. Rivera, University of California, USA
Copyright:
© 2009 Rykhlevskaia, Uddin, Kondos and Menon. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence:
Vinod Menon, Program in Neuroscience and Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 780 Welch Rd, Room 201, Stanford, CA 94305-5778, USA. e-mail: menon@stanford.edu
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