Development and Validation of a Current-BasedEEG System

Electroencephalography (EEG) measures electrical brain activity in a noninvasive manner. EEG mainly records electrical activity from radially oriented pyramidal cells in the cerebral cortex. However, EEG is less influenced by the tangentially oriented pyramidal cells. Magnetoencephalography (MEG) is influenced by the tangentially oriented pyramidal cells. However, MEG is not as widely available as EEG. Recent studies show that the combined used of EEG and MEG can improve the accuracy of source reconstruction, especially in neurological disorders (e.g. epilepsy). A current-based EEG system could allow us to record from the tangentially oriented pyramidal cells. The current work presents the development and validation of such a current-based EEG system. The system is adapted from a previously developed current-based electromyography (EMG) system. Characterization data and pilot EEG recordings in a human subject are presented. Further work will focus on miniaturizing the system to interface with the standard EEG cap, as well as developing a multichannel system.