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.
After revision:  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 , we rule out standard phase transitions to explain the emergence of collective oscillations, as they do not suffice to explain current experimental evidence.