title: Angular default mode network connectivity across working memory load.
abstract: Initially identified during no-task, baseline conditions, it has now been suggested that the default mode network (DMN) engages during a variety of working memory paradigms through its flexible interactions with other large-scale brain networks. Nevertheless, its contribution to whole-brain connectivity dynamics across increasing working memory load has not been explicitly assessed. The aim of our study was to determine which DMN hubs relate to working memory task performance during an fMRI-based n-back paradigm with parametric increases in difficulty. Using a voxel-wise metric, termed the intrinsic connectivity contrast (ICC), we found that the bilateral angular gyri (core DMN hubs) displayed the greatest change in global connectivity across three levels of n-back task load. Subsequent seed-based functional connectivity analysis revealed that the angular DMN regions robustly interact with other large-scale brain networks, suggesting a potential involvement in the global integration of information. Further support for this hypothesis comes from the significant correlations we found between angular gyri connectivity and reaction times to correct responses. The implication from our study is that the DMN is actively involved during the n-back task and thus plays an important role related to working memory, with its core angular regions contributing to the changes in global brain connectivity in response to increasing environmental demands. Hum Brain Mapp 38:41-52, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Division of Anaesthesia and Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom.|Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom.
authors.forename: D
authors.initials: D
authors.lastname: Vatansever
authors.affiliation: Division of Anaesthesia and Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom.|Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom.
authors.forename: A E
authors.initials: AE
authors.lastname: Manktelow
authors.affiliation: Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom.
authors.forename: B J
authors.initials: BJ
authors.lastname: Sahakian
authors.affiliation: Division of Anaesthesia and Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom.|Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom.
authors.forename: D K
authors.initials: DK
authors.lastname: Menon
authors.affiliation: Division of Anaesthesia and Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom.|Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom.
authors.forename: E A
authors.initials: EA
authors.lastname: Stamatakis
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D008959:Models, Neurological; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000502:physiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D011930:Reaction Time / Q000502:physiology; D011932:Reading; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: angular gyrus; behavioral performance; default mode network; functional connectivity; intrinsic connectivity contrast; n-back; working memory