Speaker
Description
Tracking changes in functional connectivity (FC) between brain regions is essential for understanding transitions between states of consciousness such as wakefulness, sleep, and anesthesia. Whole-brain models provide a framework to investigate these transitions and have predominantly been developed using functional magnetic resonance imaging (fMRI), see \cite{ponce-alvarez_hopf_2024}. However, fMRI is costly and of limited clinical applicability, motivating the development of mathematically rigorous models based on electroencephalography (EEG), which is routinely available during surgical procedures and shows correlation with the fMRI signal, as shown in \cite{fultz_coupled_2019}.
Using amplitude envelope correlation as a time-domain measure compatible with fMRI-derived FC, we identify EEG-based functional clusters based on \cite{rojas_study_2018} as done in our previous work \cite{edthofer_identifying_2025}. Analysis of simultaneous EEG-fMRI sleep recordings reveals a three-cluster structure, yielding a low-dimensional stochastic differential equation model.
Based on this reduction, we determine the parameters of a Hopf whole-brain model derived from the fMRI-based formulation, as motivated by \cite{lopez-gonzalez_loss_2021}, and investigate its dynamical properties. In particular, we analyze bifurcation structures and transitions between dynamical regimes associated with altered states of consciousness.
Bibliography
@article{ponce-alvarez_hopf_2024,
title = {The {Hopf} whole-brain model and its linear approximation},
volume = {14},
issn = {2045-2322},
url = {https://www.nature.com/articles/s41598-024-53105-0},
doi = {10.1038/s41598-024-53105-0},
language = {en},
number = {1},
urldate = {2026-03-05},
journal = {Scientific Reports},
author = {Ponce-Alvarez, Adrián and Deco, Gustavo},
month = jan,
year = {2024},
pages = {2615},
}
@article{lopez-gonzalez_loss_2021,
title = {Loss of consciousness reduces the stability of brain hubs and the heterogeneity of brain dynamics},
author = {López-González, Ane and Panda, Rajanikant and Ponce-Alvarez, Adrián and Zamora-López, Gorka and Escrichs, Anira and Martial, Charlotte and Thibaut, Aurore and Gosseries, Olivia and Kringelbach, Morten L. and Annen, Jitka and Laureys, Steven and Deco, Gustavo},
volume = {4},
issn = {2399-3642},
url = {https://www.nature.com/articles/s42003-021-02537-9},
doi = {10.1038/s42003-021-02537-9},
language = {en},
number = {1},
urldate = {2026-03-05},
journal = {Communications Biology},
month = sep,
year = {2021},
pages = {1037},
}
@article{edthofer_identifying_2025,
title = {Identifying {EEG}-based {Functional} {Networks} for {Whole}-{Brain} {Models}},
volume = {59},
issn = {24058963},
url = {https://linkinghub.elsevier.com/retrieve/pii/S2405896325002691},
doi = {10.1016/j.ifacol.2025.03.052},
language = {en},
number = {1},
urldate = {2026-03-05},
journal = {IFAC-PapersOnLine},
author = {Edthofer, Alexander and Korner, Andreas},
year = {2025},
pages = {301--306},
}
@article{rojas_study_2018,
title = {Study of {Resting}-{State} {Functional} {Connectivity} {Networks} {Using} {EEG} {Electrodes} {Position} {As} {Seed}},
volume = {12},
issn = {1662-453X},
url = {http://journal.frontiersin.org/article/10.3389/fnins.2018.00235/full},
doi = {10.3389/fnins.2018.00235},
urldate = {2026-03-05},
journal = {Frontiers in Neuroscience},
author = {Rojas, Gonzalo M. and Alvarez, Carolina and Montoya, Carlos E. and De La Iglesia-Vayá, María and Cisternas, Jaime E. and Gálvez, Marcelo},
month = apr,
year = {2018},
pages = {235},
}
@article{fultz_coupled_2019,
title = {Coupled electrophysiological, hemodynamic, and cerebrospinal fluid oscillations in human sleep},
volume = {366},
issn = {0036-8075, 1095-9203},
url = {https://www.science.org/doi/10.1126/science.aax5440},
doi = {10.1126/science.aax5440},
language = {en},
number = {6465},
urldate = {2026-03-09},
journal = {Science},
author = {Fultz, Nina E. and Bonmassar, Giorgio and Setsompop, Kawin and Stickgold, Robert A. and Rosen, Bruce R. and Polimeni, Jonathan R. and Lewis, Laura D.},
month = nov,
year = {2019},
pages = {628--631},
}
