ORDINARY LEAST-SQUARES DIPOLE LOCALIZATION IS INFLUENCED BY THE REFERENCE

It is shown empirically, analytically and in simulations that common a nd average referenced recordings differentially affect the accuracy of equivalent source estimates. This effect is mediated by the influence of the reference on noise correlations. The general conclusion of thi s analysis is that, if software only allows for ordinary least squares estimation (OLS), then average referencing should be preferred, altho ugh these estimates will still be sub-optimal. Optimal estimates are d erived by generalized least squares (GLS) which accounts for correlate d noise. With GLS, average and common referenced recordings give rise to comparable accuracy. Copyright (C) 1996 Elsevier Science Ireland Lt d.