Abstract
Functional Connectivity (FC) during resting-state or task conditions is not static but inherently dynamic. Yet, there is no consensus on whether fluctuations in FC may resemble isolated transitions between discrete FC states rather than continuous changes. This quarrel hampers advancing the study of dynamic FC. This is unfortunate as the structure of fluctuations in FC can certainly provide more information about developmental changes, aging, and progression of pathologies. We merge the two perspectives and consider dynamic FC as an ongoing network reconfiguration, including a stochastic exploration of the space of possible steady FC states. The statistical properties of this random walk deviate both from a purely “order-driven” dynamics, in which the mean FC is preserved, and from a purely “randomness-driven” scenario, in which fluctuations of FC remain uncorrelated over time. Instead, dynamic FC has a complex structure endowed with long-range sequential correlations that give rise to transient slowing and acceleration epochs in the continuous flow of reconfiguration. Our analysis for fMRI data in healthy elderly revealed that dynamic FC tends to slow down and becomes less complex as well as more random with increasing age. These effects appear to be strongly associated with age-related changes in behavioural and cognitive performance.
Original language | English |
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Article number | 117156 |
Pages (from-to) | 1-16 |
Number of pages | 16 |
Journal | NeuroImage |
Volume | 222 |
Early online date | 19 Jul 2020 |
DOIs | |
Publication status | Published - 15 Nov 2020 |
Funding
This research was supported by the Brain Network Recovery Group (through the James S. McDonnell Foundation ) and by the European Union’s Horizon 2020 Framework Program for Research and Innovation under the Specific Grant Agreement No. 785907 (Human Brain Project SGA2). DB acknowledges support from the Mission for Interdisciplinarity of the CNRS, France (Infiniti program 2017–2018, “BrainTime”), from the EU Innovative Training Network “i-CONN” (H2020 ITN 859937). DL has been funded by the Uruguayan National Agency of Research and Innovation ( ANII , grant POS EXT 2015 1 123495 ). P.R. acknowledges the following additional funding sources: H2020 Research and Innovation Action grants VirtualBrainCloud 826421 and ERC 683049; German Research Foundation CRC 1315, CRC 936 and RI 2073/6-1; Berlin Institute of Health & Foundation Charité, Johanna Quandt Excellence Initiative. We thank: Rodrigo Sigala, Sebastian Haufe, Michael Schirner, Simon Rothmeier for help in data acquisition; and Djouya Arbabyazd, Dionysios Perdikis, Rita Sleimen-Malkoun, Annette Witt and Paul Triebkorn for discussions.
Funders | Funder number |
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Berlin Institute of Health & Foundation Charit? | |
Berlin Institute of Health & Foundation Charité | |
European Union’s Horizon 2020 Framework Program for Research and Innovation | |
H2020 Research and Innovation Action | ERC 683049 |
Johanna Quandt Excellence Initiative | |
Uruguayan National Agency of Research and Innovation | |
James S. McDonnell Foundation | |
Agencia Nacional de Investigación e Innovación | POS EXT 2015 1 123495 |
Horizon 2020 Framework Programme | |
Seventh Framework Programme | 785907, 859937, 683049, 330792, 826421 |
Deutsche Forschungsgemeinschaft | RI 2073/6-1, CRC 1315, CRC 936 |
Centre National de la Recherche Scientifique | H2020 ITN 859937 |
Keywords
- Aging| anomalous diffusion
- Dynamic functional connectivity
- fMRI
- Resting-state