Variable single-trial evoked potential estimation via principal component identification

Current single-trial Evoked Potential (EP) estimators assume deterministic signal waveforms embedded in the background electroencephalographic brain activity. Identification of morphological changes of the evoked responses has been suggested, requiring however a skilled operator to predetermine the location of the variable components. In this paper the authors propose an alternative approach for the identification of variable single-trial EPs, based on reconstruction of the EPs from the Principal Components of the data correlation matrix and thus eliminating the requirement of a-priori knowledge of the variable component locations. The reconstruction performance is demonstrated via simulations and application to experimental EP data.