Repetitive TMS during specific phases of the dorsomedial prefrontal theta oscillation has differential effects on network excitability and working memory performance

Abstract Brain-state-dependent rTMS has been used for phase-specific stimulation of the μ-rhythm in motor cortex, and revealed differential efficacy of plasticity induction depending of the phase stimulated. We extended this method based on real-time analysis of EEG to target prefrontal theta, a rhythm associated with cognitive functions. By applying rTMS to the dorsomedial prefrontal cortex during different phases of the local theta oscillation, we obtained TMS-EEG excitability increase and working memory performance improvement specifically when stimulating the trough of dorsomedial prefrontal theta. This novel method may have potential for therapeutic applications in patients with cognitive disorders. Research Category and Technology and Methods Translational Research: 7. Responsive (Closed-Loop) Stimulation Keywords: EEG-TMS, Brain-state-dependent stimulation, Dorsomedial prefrontal cortex, Working memory