The intrinsic ignition framework.
Deco and Kringelbach  define four classes of network ignition, that range from (A) weak nonhierarchy to (D) graded uniform hierarchy. Between these poles, two other classes are (B) staircase hierarchy and (C) graded non-uniform hierarchy. (E) In the Human connectome, the number of nodes susceptible to be ignited is smoothly controlled by the coupling gain, as shown in the orange arrow. In the (F) DPRrw the number of ignited nodes is less controllable.