“…It has been shown that noise: (i) can “switch” between these states (Neiman et al, 1999; Bascones et al, 2002; Misic et al, 2010), (ii) induces oscillations itself (Zhou et al, 2003; Ermentrout et al, 2008; Ghosh et al, 2008), and (iii) enhances phase synchronization (Neiman et al, 1999) as well as de-synchronization (Kurrer and Schulten, 1995). When considering realistically large coupled excitable systems of model neurons, the presence of noise leads to a clustering of frequencies (Postnov et al, 2001; Sosnovtseva et al, 2001; Brunel and Hansel, 2006; Deco et al, 2009), i.e., neurons form groups characterized by (almost) the same “stochastic eigenfrequency.” The number of such clusters strongly depends on the distribution interval of coupling, the larger the coupling the less clusters form. Interestingly a relaxed notion of phase-locking is sufficient for this phenomenon to occur (Sosnovtseva et al, 2001).…”