title: Default mode network connectivity predicts sustained attention deficits after traumatic brain injury.
abstract: Traumatic brain injury (TBI) frequently produces impairments of attention in humans. These can result in a failure to maintain consistent goal-directed behavior. A predominantly right-lateralized frontoparietal network is often engaged during attentionally demanding tasks. However, lapses of attention have also been associated with increases in activation within the default mode network (DMN). Here, we study TBI patients with sustained attention impairment, defined on the basis of the consistency of their behavioral performance over time. We show that sustained attention impairments in patients are associated with an increase in DMN activation, particularly within the precuneus and posterior cingulate cortex. Furthermore, the interaction of the precuneus with the rest of the DMN at the start of the task, i.e., its functional connectivity, predicts which patients go on to show impairments of attention. Importantly, this predictive information is present before any behavioral evidence of sustained attention impairment, and the relationship is also found in a subgroup of patients without focal brain damage. TBI often results in diffuse axonal injury, which produces cognitive impairment by disconnecting nodes in distributed brain networks. Using diffusion tensor imaging, we demonstrate that structural disconnection within the DMN also correlates with the level of sustained attention. These results show that abnormalities in DMN function are a sensitive marker of impairments of attention and suggest that changes in connectivity within the DMN are central to the development of attentional impairment after TBI.
authors.affiliation: The Computational, Cognitive and Clinical Neuroimaging Laboratory, Centre for Neuroscience, Division of Experimental Medicine and The Medical Research Council Clinical Sciences Centre, Imperial College London, London W120NN, United Kingdom.
authors.forename: Valerie
authors.initials: V
authors.lastname: Bonnelle
authors.forename: Robert
authors.initials: R
authors.lastname: Leech
authors.forename: Kirsi M
authors.initials: KM
authors.lastname: Kinnunen
authors.forename: Tim E
authors.initials: TE
authors.lastname: Ham
authors.forename: Cristian F
authors.initials: CF
authors.lastname: Beckmann
authors.forename: Xavier
authors.initials: X
authors.lastname: De Boissezon
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Greenwood
authors.forename: David J
authors.initials: DJ
authors.lastname: Sharp
mesh_terms: D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D001930:Brain Injuries / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D016022:Case-Control Studies; D002755:Choice Behavior / Q000502:physiology; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology / Q000502:physiology*; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000473:pathology / Q000503:physiopathology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology