Expanded head surface EEG electrode array: an application to display the voltage topography of focal epileptiform discharges of mesiotemporal origin.

Aided by computerized voltage topographic display, conventional time-series EEG display methods were expanded. Representations of both negative and positive ends of an equivalent current dipole can be localized in EEG sampled over the head surface. Intuitive EEG analysis can be applied to source localization in three dimensions of scalp focal epileptiform discharges.