## Journal article: The polar average reference effect : a bias in estimating the head surface integral in EEG recording

No Thumbnail Available
1999
##### Editors
Junghöfer, Markus
Tucker, Don M.
Braun, Christoph
Journal article
##### Abstract
A reference-independent measure of potential is helpful for studying the multichannel EEG. The potentials integrated over the surface of the body is a constant, i.e. inactive across time, regardless of the activity and distribution of brain electric sources. Therefore, the average reference, the mean of all recording channels at each time point, may be used to approximate an inactive reference. However, this approximation is valid only with accurate spatial sampling of the scalp fields. Accurate sampling requires a sufficient electrode density and full coverage of the head's surface. If electrodes are concentrated in one region of the surface, such as just on the scalp, then the average is biased toward that region. Differences from the average will then be smaller in the center of the region, e.g. the vertex, than at the periphery. In this paper, we illustrate how this polar average reference effect (PARE) may be created by both the inadequate density and the uneven distribution of EEG electrodes. The greater the coverage of the surface of the volume conductor, the more the average reference approaches the ideal inactive reference.
150 Psychology
##### Keywords
EEG reference , EEG average reference , High resolution EEG , Evoked potential , Signal to noise ratio , Standard deviation
##### Published in
Clinical Neuropsychology ; 110 (1999). - pp. 1149-1155
##### Cite This
ISO 690JUNGHÖFER, Markus, Thomas ELBERT, Don M. TUCKER, Christoph BRAUN, 1999. The polar average reference effect : a bias in estimating the head surface integral in EEG recording. In: Clinical Neuropsychology. 110, pp. 1149-1155. Available under: doi: 10.1016/S1388-2457(99)00044-9
BibTex
@article{Junghofer1999polar-11365,
year={1999},
doi={10.1016/S1388-2457(99)00044-9},
title={The polar average reference effect : a bias in estimating the head surface integral in EEG recording},
volume={110},
journal={Clinical Neuropsychology},
pages={1149--1155},
author={Junghöfer, Markus and Elbert, Thomas and Tucker, Don M. and Braun, Christoph}
}

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