Abstract
In standard event-related potential (ERP) recordings, activity at the reference site affects measurements at all the “active” electrode sites. Analyses of ERP data would be improved if reference site activity could be separated out. Apart from current source density methods, which can miss deep or distributed events, the major alternative to an “indifferent” electrode reference is one that combines all active electrodes, subtracting out the activity common to all of them. The average reference has merits (such as an insensitivity to scalp currents near any single electrode) and limitations (such as a dependence on the number and locations of all the electrodes in the average). This review compares the effects of different references on the scalp topography of the auditory N1 recorded with an array of 128 electrodes. Furthermore, it shows how assumptions associated with each reference affect inferential methods such as analysis of variance and correlation. Finally, it seeks to evaluate the efficacy of the average reference in estimating the true zero potential line.
Article PDF
Similar content being viewed by others
References
Andino, S. L. G., Marqui, R. D. P., Sosa, P. A. V., Lirio, R. B., Machado, C., Diaz, G., Rodriguez, P. F., &Torrez, C. C. (1990). Brain electrical field measurements unaffected by linked earlobes reference.Electroencephalography & Clinical Neurophysiology,75, 155–160.
Bertrand, O., Perrin, F., &Pernier, J. (1985). A theoretical justification of the average reference in topographic evoked potential studies.Electroencephalography & Clinical Neurophysiology,62, 462–464.
Bötzel, K., Schulze, S., &Stodieck, S. R. G. (1995). Scalp topography and analysis of intracranial sources of face-evoked potentials.Experimental Brain Research,104, 135–143.
Cattell, R. B. (1966). The scree test for the number of factors.Multivariate Behavioral Research,1, 245–276.
Cattell, R. B., &Jaspers, J. (1967). A general plasmode (No. 3010-5-2) for factor analytic exercises and research.Multivariate Behavioral Research Monographs, No. 67-3, pp. 1–212.
Desmedt, J. E., Chalklin, V., &Tomberg, C. (1990). Emulation of somatosensory evoked potential (SEP) components with the 3-shell head model and the problem of “ghost potential fields” when using an average reference in brain mapping.Electroencephalography & Clinical Neurophysiology,77, 243–258.
Dien, J. (1997). Addressing misallocation of variance in principal components analysis of evoked potentials.Psychophysiology,34 (Suppl. 1), S31.
Homan, R. W., Herman, J., &Purdy, P. (1987). Cerebral location of international 10–20 system electrode placement.Electroencephalography & Clinical Neurophysiology,66, 376–382.
Jeffreys, D. A. (1989). A face-responsive potential recorded from the human scalp.Experimental Brain Research,78, 193–202.
Katznelson, R. D. (1981). EEG recording, electrode placement, and aspects of generator localization. In P. L. Nunez (Ed.),Electric fields of the brain: The neurophysics of EEG (pp. 176–213). New York: Oxford University Press.
Kooi, K. A., Tipton, A. C., &Marshall, R. E. (1971). Polarities and field configurations of the vertex components of the human auditory evoked response: A reinterpretation.Electroencephalography & Clinical Neurophysiology,31, 166–169.
Lehtonen, J. B., &Koivikko, M. J. (1971). The use of a non-cephalic reference electrode in recording cerebral evoked potentials in man.Electroencephalography & Clinical Neurophysiology,31, 154–156.
Loveless, N. E., Simpson, M., &Näätänen, R. (1987). Frontal negative and parietal positive components of the slow wave dissociated.Psychophysiology,24, 340–345.
Miller, G. A., Lutzenberger, W., &Elbert, T. (1991). The linked-reference issue in EEG and ERP recording.Journal of Psychophysiology,5, 273–276.
Näätänen, R. (1992).Attention and brain function. Hillsdale, NJ: Erlbaum.
Nunez, P. L. (1991). Comments on the paper by Miller, Lutzenberger and Elbert.Journal of Psychophysiology,5, 279–280.
Offner, F. F. (1950). The EEG as potential mapping: The value of the average monopolar reference.Electroencephalography & Clinical Neurophysiology,2, 215–216.
Osselton, J. W. (1965). Acquisition of EEG data by bipolar, unipolar and average reference methods: A theoretical comparison.Electroencephalography & Clinical Neurophysiology,19, 527–528.
Perrin, F., Pernier, J., Bertrand, D., &Echallier, J. F. (1989). Spherical splines for scalp potential and current density mapping.Electroencephalography & Clinical Neurophysiology,72, 184–187.
Ruchkin, D. S., &Sutton, S. (1983). Positive slow wave and P300: Association and dissociation. In A. W. K. Gaillard & W. Ritter (Eds.),Tutorials in ERP research: Endogenous components (pp. 233–250). Amsterdam: North-Holland.
Squires, N. K., Squires, K. C., &Hillyard, S. A. (1975). Two varieties of long-latency positive waves evoked by unpredictable auditory stimuli in man.Electroencephalography & Clinical Neurophysiology,38, 387–401.
Srinivasan, R., Tucker, D. M., &Murias, M. (1998). Estimating the spatial Nyquist of the human EEG.Behavior Research Methods, Instruments, & Computers,30, 8–19.
Tomberg, C., Noel, P., Ozaki, I., &Desmedt, J. E. (1990). Inadequacy of the average reference for the topographic mapping of focal enhancements of brain potentials.Electroencephalography & Clinical Neurophysiology,77, 259–265.
Tucker, D. M. (1993). Spatial sampling of head electrical fields: The geodesic sensor net.Electroencephalography & Clinical Neurophysiology,87, 154–163.
Vaughan, H., &Ritter, W. (1970). The sources of auditory evoked responses recorded from the human scalp.Electroencephalography & Clinical Neurophysiology,28, 360–367.
Wolpaw, J. R., &Wood, C. W. (1982). Scalp distributions of human auditory evoked potentials: I. Evaluation of reference electrode sites.Electroencephalography & Clinical Neurophysiology,54, 15–24.
Author information
Authors and Affiliations
Corresponding author
Additional information
This research was supported by the Cognitive Psychophysiology Training Grant (NIMH MH19554) at the University of Illinois, Urbana-Champaign. Thanks to Martin Eimer, Len Trejo, an anonymous reviewer, and especially Steve Luck, for their very helpful comments on a previous draft.
Rights and permissions
About this article
Cite this article
Dien, J. Issues in the application of the average reference: Review, critiques, and recommendations. Behavior Research Methods, Instruments, & Computers 30, 34–43 (1998). https://doi.org/10.3758/BF03209414
Issue Date:
DOI: https://doi.org/10.3758/BF03209414