Before revision:  Using a simple model of coupled excitable oscillators , we rule out standard phase transitions to explain the emergence of collective oscillations, as they do not suffice to explain current experimental evidence. Conversely, we uncover a novel hybrid-type of synchronization transition displaying a very-rich dynamical repertoire supporting all key empirical observations, including scale-free avalanches , marginal coherence, and bistability .
After revision:  Using a simple 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, including scale-free avalanches , marginal coherence, and bistability .