Single trial VEP source separation through sandwich Spectral Power Ratio method

In single trial source separation problem of VEP signals, the selection of legitimate Principal Components (PCs) is an important phenomenon. The Spectral Power Ratio (SPR) method developed by us earlier for PCA has proven to be capable of selecting only the required PCs in a sophisticated manner. Our continuous enhancement has lead to the current development of the proposed method, Sandwich SPR (SSPR). The SSPR performs the reconstruction of source signal in an effective way better than the related SPR method. When this technique was applied on artificial Visual Evoked Potential (VEP) signals contaminated with background electroencephalogram (EEG), with a focus on extracting P3 parameters, it was found to be feasible shown by the resulting high values of the Signal to Noise ratio (SNR) as compared to the SPR and 2 tier SPR (SPR2) methods. Subsequently, we applied this method to study the P3 amplitude responses from a set of real EEG from Wadsworth BCI dataset obtained with target and non-target stimuli, and found that the P3 parameters extracted through our proposed SSPR method showed higher P3 responses for the target stimuli than the both SPR and SPR2 methods, which conform to the existing knowledge on P3 responses.