Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique. It is a promising treatment method for patients with refractory epilepsy. However, the overall response rates remain modest and there is high inter-individual variability. Recent findings, mostly derived after motor cortex stimulation, suggest that the exact timing of the delivery of TMS pulses has crucial effects on the individual brain response. This effect was hypothesized to be related to various brain-states. In this project, it will be investigated how TMS noninvasively affects the brain cortex using an innovative approach based on real-time EEG analysis so that brain-state information can be obtained and TMS pulses can be consistently delivered during predetermined brain-states (brain-oscillation-synchronized (BOS) TMS). First, a BOS TMS setup will be realized at the 4BRAIN lab and the methodology to derive brain-states will be further investigated. Then, the BOS TMS setup will be used to study the relationship between brain-states and responses to stimulation in brain regions beyond the motor cortex. Finally, state-of-the-art neurophysiological read-out measures will be used to study the effects of BOS TMS in epilepsy patients. The findings will be used for future development of the therapeutic application of TMS in a rational way with the ultimate goal to increase clinical efficacy in brain disorders such as epilepsy.