  The question of controllability of natural and man-made network systems has
recently received considerable attention. In the context of the human brain,
the study of controllability may not only shed light into the organization and
function of different neural circuits, but also inform the design and
implementation of minimally invasive yet effective intervention protocols to
treat neurological disorders. While the characterization of brain
controllability is still in its infancy, some results have recently appeared
and given rise to scientific debate. Among these, [1] has numerically shown
that a class of brain networks constructed from DSI/DTI imaging data are
controllable from one brain region. That is, a single brain region is
theoretically capable of moving the whole brain network towards any desired
target state. In this note we provide evidence supporting controllability of
brain networks from a single region as discussed in [1], thus contradicting the
main conclusion and methods developed in [2].
