By Damián Dellavale (Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Física Médica (DFM), Instituto de Nanociencia y Nanotecnología (INN), Centro Atómico Bariloche (CAB)). November 7th, 2024.
Brain oscillations, broadband 1/f activity and neuronal avalanches (NAs) are valuable conceptualizations extensively used to interpret brain data, yet, these perspectives have mainly progressed in parallel with no current consensus on a rationale linking them. This study aims to reconcile these viewpoints.
We analyzed NAs in source-reconstructed MEG data from 47 healthy subjects during eyes-closed resting state. For this, we introduced custom measures and a comprehensive array of features characterizing the statistical, spatiotemporal and spectral properties of NAs.
The observed NAs disclose a significant spectral signature in the alpha band, suggesting that the large-scale spreading of alpha bursts occurs mainly via brain avalanches. Besides, the NAs detected in our MEG dataset can be segregated based on their spectral signature in two main groups having different propagation patterns, where cluster 2 avalanches is mainly related to the spread of narrowband alpha bursts across the brain network, whereas cluster 1 avalanches correspond to more spatially localized fluctuations promoted by the broadband 1/f activity. We also provide an analytical framework, supported by model and experimental evidence, showing that a) spectral group delay consistency in specific narrow frequency bands, b) transient cross-regional coherent oscillations and c) broadband 1/f activity, are all key ingredients for the emergence of realistic avalanches.
Contact: Damián Dellavale, dellavaledamian@gmail.com
Additional authors: Emahnuel Troisi Lopez, Institute of Applied Sciences and Intelligent Systems, National Research Council (CNR), 80078, Pozzuoli, Italy, e.troisilopez@gmail.com; Antonella Romano, University of Naples Parthenope, Department of Motor Science and Wellness, Naples, Italy, antonella.romano1997@gmail.com; Giovanni Rabuffo, Institut de Neurosciences des Systèmes, Aix-Marseille Universitè, Marseille, France, giovanni.rabuffo@univ-amu.fr; Pierpaolo Sorrentino, Institut de Neurosciences des Systèmes, Aix-Marseille Universitè, Marseille, France, pierpaolo.sorrentino@univ-amu.fr