Real-Time Electroencephalography-Triggered Transcranial Magnetic Stimulation for Cortical Excitation

Begin with a human participant wearing an EEG cap, secured with a mesh cap.

EMG electrodes were placed on the abductor pollicis brevis muscle for signal acquisition.

Use a reflective head tracker to monitor head position in real-time.

Next, position the transcranial magnetic stimulation or TMS coil over the motor cortex and deliver magnetic pulses to activate cortical neurons.

This activation evokes muscle contractions, captured as motor-evoked potentials or MEPs by the EMG electrodes.

Identify the cortical site producing the strongest MEPs and fix the coil in place.

Adjust the stimulation intensity to determine the motor threshold--the lowest intensity that reliably evokes MEPs.

Then, set the system to trigger TMS during the negative phase of the EEG signal, when cortical excitability is highest.

Initiate the EEG-synchronized TMS sequence.

EEG electrodes record brain activity, while a real-time processor detects negative phases and triggers TMS, producing consistent muscle responses.

To perform a realtime EEG-synchronized TMS experiment first determine the exact location where the TMS of the motor cortex evokes the strongest motor response from the hand muscles. Then mark this hotspot and c