PMID- 34783122 OWN - NLM STAT- MEDLINE DCOM- 20220328 LR - 20220328 IS - 1097-0193 (Electronic) IS - 1065-9471 (Print) IS - 1065-9471 (Linking) VI - 43 IP - 3 DP - 2022 Feb 15 TI - Unveiling whole-brain dynamics in normal aging through Hidden Markov Models. PG - 1129-1144 LID - 10.1002/hbm.25714 [doi] AB - During normal aging, the brain undergoes structural and functional changes. Many studies applied static functional connectivity (FC) analysis on resting state functional magnetic resonance imaging (rs-fMRI) data showing a link between aging and the increase of between-networks connectivity. However, it has been demonstrated that FC is not static but varies over time. By employing the dynamic data-driven approach of Hidden Markov Models, this study aims to investigate how aging is related to specific characteristics of dynamic brain states. Rs-fMRI data of 88 subjects, equally distributed in young and old were analyzed. The best model resulted to be with six states, which we characterized not only in terms of FC and mean BOLD activation, but also uncertainty of the estimates. We found two states were mostly occupied by young subjects, whereas three other states by old subjects. A graph-based analysis revealed a decrease in strength with the increase of age, and an overall more integrated topology of states occupied by old subjects. Indeed, while young subjects tend to cycle in a loop of states characterized by a high segregation of the networks, old subjects' loops feature high integration, with a crucial intermediary role played by the dorsal attention network. These results suggest that the employed mathematical approach captures the complex and rich brain's dynamics underpinning the aging process. CI - (c) 2021 The Authors. Human Brain Mapping published by Wiley Periodicals LLC. FAU - Moretto, Manuela AU - Moretto M AUID- ORCID: 0000-0003-4178-1854 AD - Department of Information Engineering, University of Padova, Padova, Italy. AD - Padova Neuroscience Center, University of Padova, Padova, Italy. FAU - Silvestri, Erica AU - Silvestri E AD - Department of Information Engineering, University of Padova, Padova, Italy. AD - Padova Neuroscience Center, University of Padova, Padova, Italy. FAU - Zangrossi, Andrea AU - Zangrossi A AD - Padova Neuroscience Center, University of Padova, Padova, Italy. FAU - Corbetta, Maurizio AU - Corbetta M AD - Padova Neuroscience Center, University of Padova, Padova, Italy. AD - Department of Neuroscience, University of Padova, Padova, Italy. FAU - Bertoldo, Alessandra AU - Bertoldo A AUID- ORCID: 0000-0002-6262-6354 AD - Department of Information Engineering, University of Padova, Padova, Italy. AD - Padova Neuroscience Center, University of Padova, Padova, Italy. LA - eng PT - Journal Article DEP - 20211115 PL - United States TA - Hum Brain Mapp JT - Human brain mapping JID - 9419065 SB - IM MH - Adult MH - Aged MH - Aged, 80 and over MH - Aging/*physiology MH - Brain/diagnostic imaging/*physiology MH - *Connectome MH - Female MH - Humans MH - Magnetic Resonance Imaging MH - Male MH - Markov Chains MH - Middle Aged MH - *Models, Statistical MH - Nerve Net/diagnostic imaging/*physiology MH - Young Adult PMC - PMC8764474 OTO - NOTNLM OT - Hidden Markov Models OT - brain states OT - dynamic functional connectivity OT - healthy aging OT - resting state networks EDAT- 2021/11/17 06:00 MHDA- 2022/03/29 06:00 PMCR- 2021/11/15 CRDT- 2021/11/16 07:03 PHST- 2021/10/24 00:00 [revised] PHST- 2021/08/05 00:00 [received] PHST- 2021/10/31 00:00 [accepted] PHST- 2021/11/17 06:00 [pubmed] PHST- 2022/03/29 06:00 [medline] PHST- 2021/11/16 07:03 [entrez] PHST- 2021/11/15 00:00 [pmc-release] AID - HBM25714 [pii] AID - 10.1002/hbm.25714 [doi] PST - ppublish SO - Hum Brain Mapp. 2022 Feb 15;43(3):1129-1144. doi: 10.1002/hbm.25714. Epub 2021 Nov 15.