T. Knosche et al., LINEAR-ESTIMATION DISCRIMINATES MIDLINE SOURCES AND A MOTOR CORTEX CONTRIBUTION TO THE READINESS POTENTIAL, Electroencephalography and clinical neurophysiology, 99(2), 1996, pp. 183-190
Spatiotemporal dipole modelling of the generators of the readiness pot
ential (RP) prior to voluntary movements has yielded diverging results
concerning the contributions of supplementary motor area (SMA) and pr
imary motor cortex. We applied an alternative approach (i.e, linear es
timation theory) to measurements of the RP preceding fixed and freely
selected finger movements, measured at 28 electrodes of the extended 1
0-20 system. The volume conductor properties of the head were modelled
by 3 concentric spheres. Current densities were reconstructed on a sp
herical surface, placed at a depth of 5 mm from the inside of the skul
l. Lead field normalization was applied. The analysis shows activity o
n the midline as well as near the primary motor area. Although some fe
atures of the reconstructions are not readily interpretable, separate
contributions of midline sources (including presumably SMA) and motor
cortex to the RP are clearly distinguished.