Experimental tests of EEG source localization accuracy in realistically shaped head models.

Objectives: To determine the accuracy with which electrical sources in the human brain can be located using realistically shaped boundary element models of the head and to compare this accuracy with that using spherical head models.

Methods: In a previous study, electroencephalographs (EEGs) produced by sources at known locations in the brains of human subjects were recorded. The sources were created by injecting current into implanted depth electrodes.

Effects of modeling errors and EEG measurement montage on source localization accuracy.

The location of an electrical source in the brain can be determined from the EEGs the source produces on the scalp by calculating the location of a source in a model of the head using the EEGs. Modeling errors produced by differences between the actual head and the head model cause localization errors (i.e.

Experimental tests of EEG source localization accuracy in spherical head models.

Objectives: The locations of electrical sources in the brain can be calculated using EEG data. However, the accuracy of these calculations is not well known because it is usually not possible to compare calculated source locations with actual locations since little accurate location information is available about most sources in the brain.

Methods: In this study, sources at known locations are created by injecting current into electrodes implanted in the brains of human subjects.

Accuracy of EEG dipole source localization using implanted sources in the human brain.

Objectives: The location of electrical sources in the brain can be estimated by calculating inverse solutions in which the location, amplitude and orientation of the electrical sources are fitted to the scalp EEG. To assess localization accuracy of the moving dipole inverse solution algorithm (ISA), we studied two patients who had depth electrodes implanted for presurgical planning of epilepsy surgery.

Methods: Artificial dipoles were created by connecting a single sine wave pulse generator to different pairs of electrodes in multiple orientations and depths.