Separation and localization of auditory and visual P300 sources in schizophrenia patients via constrained BSS

To separate and localize the P300 sources within the brain, a robust constrained blind source separation (CBSS) algorithm has been proposed. The algorithm is an extension of the Infomax algorithm, based on minimization of mutual information, for which a reference P300 signal is used as a constraint. The reference signal forces the unmixing matrix to separate the sources of both auditory and visual P300 resulting from the corresponding stimulations. The constrained problem is then converted to an unconstrained problem by means of a set of nonlinear penalty functions. The P300 sources are then localized based on electrode source inner products.