Brain-state dependent TMS triggered by individual cortical source activity using online beamforming

EEG synchronized TMS is a powerful tool to investigate the role of brain oscillations in the modulation of excitability and plasticity by enabling specific phases to be differentially targeted in a closed-loop TMS paradigm. Using a 5-channel sensor level Laplacian montage centered on the EEG electrode C3 to isolate ongoing sensorimotor μ-oscillations, a correspondence between the negative peak of the μ-oscillation and states of high corticospinal excitability gating the induction of LTP like effects has been previously demonstrated but this standard montage is arbitrary and not always effective.