Application of a cepstral distance measure in evoked potential processing

Transient evoked potentials (EPs) are variations of the on-going electroencephalogram (EEG) in response to the application of sensory stimuli. Since their amplitudes are very small in comparison to the spontaneous EEG, signal extraction methods must be applied to improve the signal-to-noise ratio. A short review of commonly used signal processing methods in EP research is given, concentrating on their assumptions and limitations. Subsequently a parametric system model is proposed which considers the characteristics of the on-going EEG preceding the stimulus in the EP processing. In order to show the advantage of this approach some results are given and their impact on the aforementioned methods is discussed.