A SPATIOTEMPORAL DIPOLE MODEL OF THE READINESS POTENTIAL IN HUMANS .1. FINGER MOVEMENT

Preceding unilateral finger movements readiness potentials (RPs) were recorded in 9 right-handed subjects. The data are presented as time se ries, potential maps and spatio-temporal dipole models. The latter are interpreted with respect to the underlying generators of the RP. Expl icit hypotheses about the unilateral or bilateral activation of partic ular sensorimotor areas preceding unilateral movements are addressed. The choice for the best spatio-temporal dipole model was guided by a t est on the orthogonality of the individual residuals and by a priori n europhysiological evidence. From the final model it is concluded that the initial bilateral symmetrical part of the RP is generated in the p osterior walls of the precentral gyrus bilaterally, whereas the later lateralized components originate from the crown of that same gyrus con tralaterally. This confirms and extends data from subdural recording, magnetoencephalography (MEG) and EEG.