Functional and structural alterations of the intraparietal sulcus in a developmental dyscalculia of genetic origin.
Cognitive theories of numerical representation suggest that understanding of numerical quantities is driven by a magnitude representation associated with the intraparietal sulcus and possibly under genetic control. The aim of this study was to investigate, using fMRI and structural imaging, the interaction between the abnormal development of numerical representation in an X-linked condition, Turner syndrome (TS), and the development of the intraparietal sulcus. fMRI during exact and approximate calculation in TS showed an abnormal modulation of intraparietal activations as a function of number size. Morphological analysis revealed an abnormal length, depth, and sulcal geometry of the right intraparietal sulcus, suggesting an important disorganization of this region in TS. Thus, a genetic form of developmental dyscalculia can be related to both functional and structural anomalies of the right intraparietal sulcus, suggesting a crucial role of this region in the development of arithmetic abilities.
Molko
Nicolas
N
INSERM U 562, Cognitive Neuroimaging, Service Hospitalier Frédéric Joliot, CEA/DSV, IFR 49 Orsay, France. molko@wanadoo.fr
Cachia
Arnaud
A
Rivière
Denis
D
Mangin
Jean François
JF
Bruandet
Marie
M
Le Bihan
Denis
D
Cohen
Laurent
L
Dehaene
Stanislas
S
D000328:Adult; D001931:Brain Mapping; D041321:Chromosomes, Human, X / Q000235:genetics; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D014644:Genetic Variation / Q000235:genetics; D006801:Humans; D007859:Learning Disabilities / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology; D008279:Magnetic Resonance Imaging; D008297:Male; D008433:Mathematics; D009415:Nerve Net / Q000002:abnormalities / Q000473:pathology / Q000503:physiopathology; D009421:Nervous System Malformations / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology; D009434:Neural Pathways / Q000002:abnormalities / Q000473:pathology / Q000503:physiopathology; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000002:abnormalities* / Q000473:pathology / Q000503:physiopathology*; D014424:Turner Syndrome / Q000150:complications* / Q000503:physiopathology / Q000523:psychology