STIMUSURE · Simultaneous magnetic brain stimulation and measurement

Current methods for directly measuring the connectivity between brain regions are lacking. A causal measurement of a functional connection between two brain regions requires stimulation of the first region whilst measuring the response from the other. Stimulation with high spatio-temporal resolution can be delivered with transcranial magnetic stimulation (TMS), but there are no suitable methods for simultaneously measuring the response with high spatio-temporal resolution. The state-of-the-art functional neuroimaging modalities have either too low spatial resolution, too low temporal resolution, or, in case of magnetoencephalography (MEG), are considered incompatible with TMS. With STIMUSURE, we aim to solve this incompatibility issue between TMS and MEG and build the first TMS–MEG device. During this two-year project, I will design magnetic shielding to enable TMS inside a magnetically shielded room (MSR) and build TMS-compatible resilient optically pumped magnetometers (OPM) based on nonlinear magneto-optical rotation (NMOR) technique. Unlike earlier ultra-sensitive magnetic field sensors, these NMOR-OPM sensors can tolerate the magnetic field pulses due to TMS. Ultimately, such a device would allow accurate measurement of the functional connectivity and quantifying its task-specific modulation, which would benefit both cognitive neuroscience and the study of brain disorders.