PMID- 35516809 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20220507 IS - 1662-4548 (Print) IS - 1662-453X (Electronic) IS - 1662-453X (Linking) VI - 16 DP - 2022 TI - Multiframe Evolving Dynamic Functional Connectivity (EVOdFNC): A Method for Constructing and Investigating Functional Brain Motifs. PG - 770468 LID - 10.3389/fnins.2022.770468 [doi] LID - 770468 AB - The study of brain network connectivity as a time-varying property began relatively recently and, to date, has remained primarily concerned with capturing a handful of discrete static states that characterize connectivity as measured on a timescale shorter than that of the full scan. Capturing group-level representations of temporally evolving patterns of connectivity is a challenging and important next step in fully leveraging the information available in large resting state functional magnetic resonance imaging (rs-fMRI) studies. We introduce a flexible, extensible data-driven framework for the stable identification of group-level multiframe (movie-style) dynamic functional network connectivity (dFNC) states. Our approach employs uniform manifold approximation and embedding (UMAP) to produce a continuity-preserving planar embedding of high-dimensional time-varying measurements of whole-brain functional network connectivity. Planar linear exemplars summarizing dominant dynamic trends across the population are computed from local linear approximations to the two-dimensional 2D embedded trajectories. A high-dimensional representation of each 2D exemplar segment is obtained by averaging the dFNC observations corresponding to the n planar nearest neighbors of tau evenly spaced points along the 2D line segment representation (where n is the UMAP number-of-neighbors parameter and tau is the temporal duration of trajectory segments being approximated). Each of the 2D exemplars thus "lifts" to a multiframe high-dimensional dFNC trajectory of length tau. The collection of high-dimensional temporally evolving dFNC representations (EVOdFNCs) derived in this manner are employed as dynamic basis objects with which to characterize observed high-dimensional dFNC trajectories, which are then expressed as weighted combination of these basis objects. Our approach yields new insights into anomalous patterns of fluidly varying whole-brain connectivity that are significantly associated with schizophrenia as a broad diagnosis as well as with certain symptoms of this serious disorder. Importantly, we show that relative to conventional hidden Markov modeling with single-frame unvarying dFNC summary states, EVOdFNCs are more sensitive to positive symptoms of schizophrenia including hallucinations and delusions, suggesting that a more dynamic characterization is needed to help illuminate such a complex brain disorder. CI - Copyright (c) 2022 Miller, Vergara, Pearlson and Calhoun. FAU - Miller, Robyn L AU - Miller RL AD - The Tri-Institutional Center for Translational Research in Neuroimaging and Data Science (TReNDS): Georgia State University, Georgia Institute of Technology and Emory University, Atlanta, GA, United States. FAU - Vergara, Victor M AU - Vergara VM AD - The Tri-Institutional Center for Translational Research in Neuroimaging and Data Science (TReNDS): Georgia State University, Georgia Institute of Technology and Emory University, Atlanta, GA, United States. FAU - Pearlson, Godfrey D AU - Pearlson GD AD - Yale School of Medicine, New Haven, CT, United States. FAU - Calhoun, Vince D AU - Calhoun VD AD - The Tri-Institutional Center for Translational Research in Neuroimaging and Data Science (TReNDS): Georgia State University, Georgia Institute of Technology and Emory University, Atlanta, GA, United States. LA - eng PT - Journal Article DEP - 20220419 PL - Switzerland TA - Front Neurosci JT - Frontiers in neuroscience JID - 101478481 PMC - PMC9063321 OTO - NOTNLM OT - dynamic functional network connectivity (dFNC) OT - functional magnetic resonance imaging (fMRI) OT - functional network connectivity (FNC) OT - resting state fMRI OT - schizophrenia OT - uniform manifold approximation and embedding (UMAP) COIS- The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. EDAT- 2022/05/07 06:00 MHDA- 2022/05/07 06:01 PMCR- 2022/01/01 CRDT- 2022/05/06 05:45 PHST- 2021/09/03 00:00 [received] PHST- 2022/01/24 00:00 [accepted] PHST- 2022/05/06 05:45 [entrez] PHST- 2022/05/07 06:00 [pubmed] PHST- 2022/05/07 06:01 [medline] PHST- 2022/01/01 00:00 [pmc-release] AID - 10.3389/fnins.2022.770468 [doi] PST - epublish SO - Front Neurosci. 2022 Apr 19;16:770468. doi: 10.3389/fnins.2022.770468. eCollection 2022.