Hybrid-type synchronization transitions: Where incipient oscillations, scale-free avalanches, and bistability live together Buendía, Víctor Villegas Góngora, Pablo Burioni, Raffaella Muñoz Martínez, Miguel Ángel M.A.M. acknowledges the Spanish Ministry and Agencia Estatal de investigacion (AEI) through Grant FIS2017-84256-P (European Regional Development Fund), as well as the Consejera de Conocimiento, Investigacin Universidad, Junta de Andaluca, and European Regional Development Fund, Ref. A-FQM-175-UGR18 and SOMM17/6105/UGR for financial support. V.B and R.B. acknowledge funding from the INFN BIOPHYS project. We also thank Cariparma for their support through the TEACH IN PARMA project. We thank S. di Santo, G. Barrios, D. Pazo, and J. Zierenberg for very valuable discussions and comments. The human cortex is never at rest but in a state of sparse and noisy neural activity that can be detected at broadly diverse resolution scales. It has been conjectured that such a state is best described as a critical dynamical process-whose nature is still not fully understood-where scale-free avalanches of activity emerge at the edge of a phase transition. In particular, some works suggest that this is most likely a synchronization transition, separating synchronous from asynchronous phases. Here, by investigating a simplified model of coupled excitable oscillators describing the cortex dynamics at a mesoscopic level, we investigate the possible nature of such a synchronization phase transition. Within our modeling approach we conclude that-in order to reproduce all key empirical observations, such as scale-free avalanches and bistability, on which fundamental functional advantages rely-the transition to collective oscillatory behavior needs to be of an unconventional hybrid type, with mixed features of type-I and type-II excitability, opening the possibility for a particularly rich dynamical repertoire. 2021-07-16T07:42:02Z 2021-07-16T07:42:02Z 2021-06-21 journal article Buendía, V... [et al.] (2021). Hybrid-type synchronization transitions: Where incipient oscillations, scale-free avalanches, and bistability live together. Physical Review Research, 3(2), 023224. DOI: [10.1103/PhysRevResearch.3.023224] http://hdl.handle.net/10481/69737 10.1103/PhysRevResearch.3.023224 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España American Physical Society