  The ability to modulate brain states using targeted stimulation is
increasingly being employed to treat neurological disorders and to enhance
human performance. Despite the growing interest in brain stimulation as a form
of neuromodulation, much remains unknown about the network-level impact of
these focal perturbations. To study the system wide impact of regional
stimulation, we employ a data-driven computational model of nonlinear brain
dynamics to systematically explore the effects of targeted stimulation.
Validating predictions from network control theory, we uncover the relationship
between regional controllability and the focal versus global impact of
stimulation, and we relate these findings to differences in the underlying
network architecture. Finally, by mapping brain regions to cognitive systems,
we observe that the default mode system imparts large global change despite
being highly constrained by structural connectivity. This work forms an
important step towards the development of personalized stimulation protocols
for medical treatment or performance enhancement.
