Application of linearly-constrained prewhitening beamformer to reconstruction of highly correlated EEG signal sources

In this study, we compared the performances of minimum variance beamformer (MVBF), linearly-constrained (LC)-MVBF, prewhitening beamformer (PWBF), and LC-PWBF with regard to the estimation of signal location in the brain neocortex. Equivalent current dipoles were located in the primary motor cortex in performed numerical simulations by considering applications in brain-computer interfaces based on modulation of μ and β rhythms. It was confirmed that when the signals were highly correlated, the location bias of LC-PWBF was smaller than that of MVBF, LC-MVBF, and PWBF. Obtained results suggest that LC-PWBF is useful for estimating the location of signal sources that are highly correlated and have low signal-to-noise ratio.