title: Changes in resting connectivity with age: a simultaneous electroencephalogram and functional magnetic resonance imaging investigation.
abstract: Resting fluctuations in the blood oxygenation level-dependent signal have attracted considerable interest for their sensitivity to pathological brain processes. However, these analyses are susceptible to confound by nonneural physiological factors such as vasculature, breathing, and head movement which is a concern when investigating elderly or pathological groups. Here, we used simultaneous electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) (EEG/fMRI) to constrain the analysis of resting state networks (RSNs) and identify aging differences. Four of 26 RSNs showed fMRI and EEG/fMRI group differences; anterior default-mode network, left frontal-parietal network, bilateral middle frontal, and postcentral gyri. Seven RSNs showed only EEG/fMRI differences suggesting the combination of these 2 methods might be more sensitive to age-related neural changes than fMRI alone. Five RSNs showed only fMRI differences and might reflect nonneural group differences. Activity within some EEG/fMRI RSNs was better explained by neuropsychological measures (Mini Mental State Examination and Stroop) than age. These results support previous studies suggesting that age-related changes in specific RSNs are neural in origin, and show that changes in some RSNs relate better to elderly cognition than age.
authors.affiliation: Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland. balsterj@tcd.ie
authors.forename: Joshua Henk
authors.initials: JH
authors.lastname: Balsters
authors.forename: Redmond G
authors.initials: RG
authors.lastname: O'Connell
authors.forename: Alessandra
authors.initials: A
authors.lastname: Galli
authors.forename: Hugh
authors.initials: H
authors.lastname: Nolan
authors.forename: Eleanora
authors.initials: E
authors.lastname: Greco
authors.forename: Sophia M
authors.initials: SM
authors.lastname: Kilcullen
authors.forename: Arun L W
authors.initials: AL
authors.lastname: Bokde
authors.forename: Robert
authors.initials: R
authors.lastname: Lai
authors.forename: Neil
authors.initials: N
authors.lastname: Upton
authors.forename: Ian H
authors.initials: IH
authors.lastname: Robertson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D001921:Brain / Q000033:anatomy & histology / Q000473:pathology / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000033:anatomy & histology / Q000473:pathology / Q000502:physiology; D009483:Neuropsychological Tests; D012146:Rest / Q000502:physiology*; D055815:Young Adult