title: Reduced functional connectivity during working memory in Turner syndrome.
abstract: Turner syndrome (TS) is a genetic disorder affecting females, resulting from the complete or partial absence of an X chromosome. The cognitive profile of TS shows relative strengths in the verbal domain and weaknesses in the procedural domain, including working memory. Neuroimaging studies have identified differences in the morphology of the parietal lobes, and white matter pathways linking frontal and parietal regions, as well as abnormal activation in dorsal frontal and parietal regions. Taken together these findings suggest that abnormal functional connectivity between frontal and parietal regions may be related to working memory impairments in TS, a hypothesis we tested in the present study. We scanned TS and typically developing participants with functional magnetic resonance imaging while they performed visuospatial and phonological working memory tasks. We generated a seed region in parietal cortex based on structural differences in TS and found that functional connectivity with dorsal frontal regions was reduced during working memory in TS. Finally, we found that connectivity was correlated with task performance in TS. These findings suggest that structural brain abnormalities in TS affect not only regional activity but also the functional interactions between regions and that this has important consequences for behavior.
authors: Center for Interdisciplinary Brain Sciences Research, Stanford University School of Medicine, Palo Alto, CA 94305, USA. signeb@stanford.edu
authors: Signe
authors: S
authors: Bray
authors: Bria
authors: B
authors: Dunkin
authors: David S
authors: DS
authors: Hong
authors: Allan L
authors: AL
authors: Reiss
mesh_terms: D000293:Adolescent; D001931:Brain Mapping; D002648:Child; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008569:Memory Disorders / Q000503:physiopathology; D008570:Memory, Short-Term / Q000502:physiology*; D009434:Neural Pathways / Q000503:physiopathology*; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000503:physiopathology*; D014424:Turner Syndrome / Q000503:physiopathology*