Figure 4.

Network controllability. (A) Multiperturbation methods can be used to activate and/or silence multiple brain regions simultaneously (here R₁ and R₃). (B) Such perturbations can be used to attempt to steer the trajectory of the system from some initial state, I, toward a final target state. Here, the state of the system can be represented as a point in four dimensions, each corresponding to the activity level at an individual region. The temporal evolution of the system along the state space corresponds to a trajectory.