title: Default mode network connectivity during task execution.
abstract: Initially described as task-induced deactivations during goal-directed paradigms of high attentional load, the unresolved functionality of default mode regions has long been assumed to interfere with task performance. However, recent evidence suggests a potential default mode network involvement in fulfilling cognitive demands. We tested this hypothesis in a finger opposition paradigm with task and fixation periods which we compared with an independent resting state scan using functional magnetic resonance imaging and a comprehensive analysis pipeline including activation, functional connectivity, behavioural and graph theoretical assessments. The results indicate task specific changes in the default mode network topography. Behaviourally, we show that increased connectivity of the posterior cingulate cortex with the left superior frontal gyrus predicts faster reaction times. Moreover, interactive and dynamic reconfiguration of the default mode network regions' functional connections illustrates their involvement with the task at hand with higher-level global parallel processing power, yet preserved small-world architecture in comparison with rest. These findings demonstrate that the default mode network does not disengage during this paradigm, but instead may be involved in task relevant processing.
authors.affiliation: Division of Anaesthesia and Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK; Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK. Electronic address: ddsv2@cam.ac.uk.
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, UK; Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK.
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, UK; Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK.
authors.forename: A E
authors.initials: AE
authors.lastname: Manktelow
authors.affiliation: Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, UK.
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, UK; Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK.
authors.forename: E A
authors.initials: EA
authors.lastname: Stamatakis
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009043:Motor Activity; D009434:Neural Pathways / Q000502:physiology; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time; D055815:Young Adult
keywords: Default mode network; Finger opposition task; Functional connectivity; Graph theory; Hierarchical clustering