title: Age-related changes in functional network connectivity associated with high levels of verbal fluency performance.
abstract: The relative preservation of receptive language abilities in older adults has been associated with adaptive changes in cerebral activation patterns, which have been suggested to be task-load dependent. However, the effects of aging and task demands on the functional integration of neural networks contributing to speech production abilities remain largely unexplored. In the present functional neuroimaging study, data-driven spatial independent component analysis and hierarchical measures of integration were used to explore age-related changes in functional connectivity among cortical areas contributing to semantic, orthographic, and automated word fluency tasks in healthy young and older adults, as well as to assess the effect of age and task demands on the functional integration of a verbal fluency network. The results showed that the functional integration of speech production networks decreases with age, while at the same time this has a marginal effect on behavioral outcomes in high-performing older adults. Moreover, a significant task demand/age interaction was found in functional connectivity within the anterior and posterior subnetworks of the verbal fluency network. These results suggest that local changes in functional integration among cortical areas supporting lexical speech production are modulated by age and task demands.
authors.affiliation: Department of Psychology, Université de Montréal, Montréal, Québec, Canada; Centre de recherche, Institut universitaire de gériatrie de Montréal, Montréal, Québec, Canada.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Marsolais
authors.affiliation: LINeM, Inserm, Université de Montréal, Montréal, Québec, Canada; U678, Inserm, Laboratoire d'Imagerie Fonctionnelle, Paris, France; UMR-S, U678, UPMC, Université Pierre et Marie Curie, Faculté de médecine Pitié-Salpêtrière, Paris, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Perlbarg
authors.affiliation: LINeM, Inserm, Université de Montréal, Montréal, Québec, Canada; U678, Inserm, Laboratoire d'Imagerie Fonctionnelle, Paris, France; UMR-S, U678, UPMC, Université Pierre et Marie Curie, Faculté de médecine Pitié-Salpêtrière, Paris, France.
authors.forename: Habib
authors.initials: H
authors.lastname: Benali
authors.affiliation: Centre de recherche, Institut universitaire de gériatrie de Montréal, Montréal, Québec, Canada; Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada. Electronic address: yves.joanette@umontreal.ca.
authors.forename: Yves
authors.initials: Y
authors.lastname: Joanette
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D001288:Attention / Q000502:physiology; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology*; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D013060:Speech / Q000502:physiology*; D055815:Young Adult
keywords: Functional connectivity; Language networks; Normal aging; Verbal fluency; fMRI