Simultaneous recordings of MEG and intracerebral EEG

Abstract

Intracerebral EEG, performed in patients during presurgical evaluation of epilepsy, provides a unique opportunity for recording directly from brain structures in humans. From a neuroscientific point of view, this allows investigating brain networks at a mesoscopic scale, with high spatial precision and time-frequency sensitivity. From a methodological perspective, this provides a "ground truth" to which MEG results can be compared. As brain activity fluctuates across sessions and across time within a session, it is necessary to record the signals simultaneously in order to ensure that the same signals are captured in both depth (SEEG) and surface (MEG) measurements. In this chapter, we introduce the practical challenges that are encountered for recording MEG and intracerebral EEG together, as well as the new venues offered by this unique combination of invasive and noninvasive recordings in humans.