RT Journal Article
SR Electronic
T1 Functional Connectivity Dynamics of the Resting State across the Human Adult Lifespan
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 107243
DO 10.1101/107243
A1 Demian Battaglia
A1 Thomas Boudou
A1 Enrique C. A. Hansen
A1 Sabrina Chettouf
A1 Andreas Daffertshofer
A1 A. Randal McIntosh
A1 Joelle Zimmermann
A1 Petra Ritter
A1 Viktor Jirsa
YR 2017
UL http://biorxiv.org/content/early/2017/02/09/107243.abstract
AB The aging brain undergoes alterations of Structural Connectivity (SC), but also transformations of the flexible interactions between brain regions during cognition, described by Functional Connectivity (FC). FC in the resting state (rs) displays a variety of age-related changes, but most studies do not address the spontaneous reorganization of FC across time. Here, we show by means of functional MRI (fMRI) human brain imaging that aging also profoundly impacts on the dynamics of this rs FC. Analyzing time-dependent correlations between human rs fMRI blood oxygen level dependent (BOLD) time series, we reveal a switching, markedly slowing down with age, between epochs of meta-stable FC and transients of fast network reconfiguration. Furthermore, we identify communities of functional links whose temporal fluctuations become increasingly anti-correlated in elderly subjects. This effect is stronger when the performance is reduced in cognitive screening tasks. Such remodeling of Functional Connectivity Dynamics (FCD) discloses qualitatively novel effects of aging that cannot be captured by variations of SC or static FC. Our new metrics manifest thus a strong biomarking potential, by achieving a quantitative parameterization of FCD variations across the human adult lifespan.Significance statement Aging alters the brain’s anatomical connectivity and inter-regional activity correlations (Functional Connectivity, or FC). Here we show that aging also affects the temporal remodeling of FC networks (Functional Connectivity Dynamics, or FCD) during the resting state. By analyzing human fMRI data, we find that the speed of FCD decreases with age. Furthermore FCD properties predict differences in cognitive performance between same-age subjects. This slowing down of FCD intriguingly parallels the reduction in information processing speed often invoked as a cause of age-related cognitive decline. We believe that FCD analyses will lead to better biomarkers of healthy and pathologic aging, since they avoid misinterpreting temporal as inter-subject variability.