Evaluation of single epoch evoked potentials.

The usual method for extracting evoked potentials from EEG, the so-called averaging, is based on the hypothesis of the stationarity of the single responses in every EEG segment. Therefore, the possible variability of the single responses cannot be regarded. In this paper, a method for estimating single evoked responses will be proposed and compared with other procedures. The principle of this method is the extraction of periodic signals from noise by autoregressive-moving average (ARMA) time series analysis. The procedure is tested by simulation studies. The applicability of the method will be demonstrated by clinical examples. It will be shown that the single response is not a stationary signal.