Estimating and Testing the Sources of Evoked Potentials in the Brain.

The source of an event related brain potential (ERP) is estimated from multivariate measurements of this ERP on the head under several mathematical and physical constraints on the parameters of the source model. We will discuss statistical aspects of standard methods to estimate these parameters and their confidence intervals. In addition new principled tests of the goodness of fit as well as of differences between estimated sources are proposed and compared with customary approaches in psychophysiology. Several factors which influence the statistical analysis, in particular the number of measurement leads, will be discussed.