Cortical potential imaging of movement-related potentials using parametric Wiener filter in realistic-shaped head model.

Suitable spatial filters were explored for inverse estimation of cortical potential imaging from the scalp electroencephalogram. The effects of incorporating signal and noise covariance into inverse procedures were examined by computer simulations and experimental study. The parametric Wiener filter (PWF) was applied to an inhomogeneous three-sphere head model under various signal and noise conditions. We also examined estimation methods for the signal covariance in PWF. The present simulation results suggest that the PWF with modified matrix transformation method has better performance. The proposed methods were applied to self-paced movement-related potentials in order to identify the anatomic substrate locations of neural generators in realistic-shaped head model. The proposed methods demonstrated that the contralateral premotor cortex was preponderantly activated in relation to movement performance.