Biological Cybernetics

, Volume 41, Issue 3, pp 211–222 | Cite as

A posteriori time-varying filtering of averaged evoked potentials

I. Introduction and conceptual basis
  • J. P. C. de Weerd


This paper forms a preface and introduction to a new method for the estimation of evoked potentials: a posteriori time-varying filtering. A simple evoked potential model, consisting of a transient signal and additive noise, is discussed and the underlying assumptions explicitly formulated. Assuming this model, the problem of estimating the signal from an ensemble is considered from the statistical and communication engineering point of view, along with a brief survey of the pertinent literature. It is explained why ensemble averaging, in general, does not provide the best estimate in the mean-square error sense. After a summary of the controversial aspects of timeinvariant “a posteriori ‘Wiener’ filtering”, it is indicated how that method can be generalized to a time-varying counterpart, which is able to handle the essentially transient character of evoked potential waveforms. Finally, the new method is presented on a conceptual level and its application illustrated by examples.


Communication Engineering Potential Model Additive Noise Ensemble Average Conceptual Level 
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Copyright information

© Springer-Verlag 1981

Authors and Affiliations

  • J. P. C. de Weerd
    • 1
  1. 1.Radboud Hospital, Department of Clinical NeurophysiologyUniversity of NijmegenNijmegenThe Netherlands

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