State diagram in the plane. Four types of population states exist. 3-cluster burst synchronization occurs in the black region, denoted by while non-cluster burst synchronization occurs in the dark gray region, represented by Cluster desynchronization appears in the gray region, denoted by while non-cluster desynchronization appears in the remaining white region, represented by Vertical arrows (I, II, and III) represent routes for , 4.5, and 10 where effects of stochastic noise are studied