Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.29.164343v1?rss=1 Authors: Escrichs, A., Biarnes, C., Garre-Olmo, J., Fernandez-Real, J. M., Ramos, R., Pamplona, R., Brugada, R., Serena, J., Ramio-Torrenta, L., Coll-De-Tuero, G., Gallart, L., Barretina, J., Vilanova, J. C., Mayneris-Perxachs, J., Essig, M., Figley, C. R., Pedraza, S., Puig, J., Deco, G. Abstract: Normal aging causes disruptions in the brain that can lead to cognitive decline. Resting-state fMRI studies have found significant age-related alterations in functional connectivity across various networks. Nevertheless, most of the studies have focused mainly on static functional connectivity. Studying the dynamics of resting-state brain activity across the whole-brain functional network can provide a better characterization of age-related changes. Here we employed two data-driven whole-brain approaches based on the phase synchronization of blood-oxygen-level-dependent (BOLD) signals to analyze resting-state fMRI data from 620 subjects divided into two groups ('middle-age group' (n=310); age range, 50-65 years vs. 'senior group' (n=310); age range, 66-91 years). Applying the Intrinsic-Ignition Framework to assess the effect of spontaneous local activation events on local-global integration, we found that the senior group showed higher intrinsic ignition across the whole-brain functional network, but lower metastability. Using Leading Eigenvector Dynamics Analysis, we found that the senior group showed reduced ability to access a metastable substate that closely overlaps with the so-called rich club. These findings suggest that functional whole-brain dynamics are altered in aging, probably due to a deficiency in a metastable substate that is key for efficient global communication in the brain. Copy rights belong to original authors. Visit the link for more info