title: Older but still fluent? Insights from the intrinsically active baseline configuration of the aging brain using a data driven graph-theoretical approach.
abstract: A major part of our knowledge about the functioning of the aging brain comes from task-induced activation paradigms. However, the aging brain's intrinsic functional organization may be already a limiting factor for the outcome of an actual behavior. In order to get a better understanding of how this functional baseline configuration of the aging brain may affect cognitive performance, we analyzed task-free fMRI data of older 186 participants (mean age=70.4, 97 female) and their performance data in verbal fluency: First, we conducted an intrinsic connectivity contrast analysis (ICC) for the purpose of evaluating the brain regions whose degree of connectedness was significantly correlated with fluency performance. Secondly, using connectivity analyses we investigated how the clusters from the ICC functionally related to the other major resting-state networks. Apart from the importance of intact fronto-parietal long-range connections, the preserved capacity of the DMN for a finely attuned interaction with the executive-control network and the language network seems to be crucial for successful verbal fluency performance in older people. We provide further evidence that the right frontal regions might be more prominently affected by age-related decline.
authors.affiliation: University Research Priority Program (URPP), Dynamics of Healthy Aging, University of Zurich, Switzerland; International Normal Aging and Plasticity Imaging Center (INAPIC), University of Zurich, Switzerland; Division Neuropsychology, Institute of Psychology, University of Zurich, Switzerland. Electronic address: angelamartina.mueller@uzh.ch.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Muller
authors.affiliation: University Research Priority Program (URPP), Dynamics of Healthy Aging, University of Zurich, Switzerland; International Normal Aging and Plasticity Imaging Center (INAPIC), University of Zurich, Switzerland; Division Neuropsychology, Institute of Psychology, University of Zurich, Switzerland. Electronic address: s.merillat@inapic.uzh.ch.
authors.forename: Susan
authors.initials: S
authors.lastname: Mérillat
authors.affiliation: University Research Priority Program (URPP), Dynamics of Healthy Aging, University of Zurich, Switzerland; International Normal Aging and Plasticity Imaging Center (INAPIC), University of Zurich, Switzerland; Division Neuropsychology, Institute of Psychology, University of Zurich, Switzerland; Center for Integrative Human Physiology (ZIHP), University of Zurich, Switzerland. Electronic address: lutz.jaencke@uzh.ch.
authors.forename: Lutz
authors.initials: L
authors.lastname: Jäncke
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways; D013060:Speech / Q000502:physiology*
keywords: Compensation; Default mode network; Functional plasticity; HAROLD; Resting-state; fMRI