  Oscillatory synchrony is hypothesized to support the flow of information
between brain regions, with different phase-locked configurations enabling
activation of different effective interactions. Along these lines, past work
has proposed multistable phase-locking as a means for hardwired brain networks
to flexibly support multiple functional patterns, without having to reconfigure
their anatomical connections. Given the potential link between interareal
communication and phase-locked states, it is thus important to understand how
those states might be controlled to achieve rapid alteration of functional
connectivity in interareal circuits. Here, we study functional state control in
small networks of coupled neural masses that display collective multistability
under determinstic conditions, and that display more biologically-realistic
irregular oscillations and transient phase-locking when conditions are
stochastic. In particular, we investigate the global responses of these
mesoscale circuits to external signals that target only a single subunit.
Focusing mainly on the more realistic scenario wherein network dynamics are
stochastic, we identify conditions under which local inputs (i) can trigger
fast transitions to topologically distinct functional connectivity motifs that
are temporarily stable ("state switching"), (ii) can smoothly adjust the
spatial pattern of phase-relations for a particular set of lead-lag
relationships ("state morphing"), and (iii) fail to regulate global
phase-locking states. In total, our results add to a growing literature
highlighting that the modulation of multistable, interareal coherence patterns
could provide a basis for flexible brain network operation.
