Localization error of a 150-channel whole-cortex magnetoencephalography system

Assuming the human head to bf a spherical conductor, we used a numerical st udy to obtain the localization error of the helmet-shaped 150-channel SQUID magnetoencephalography system. 95 % confidence limits for the dipole param eters were estimated using the semi-analytical formula. The error was compa red with the results of a Monte Carlo simulation obtained by solving the in verse problem. Using the methods, we found that the magnetometer system was superior to the gradiometer system in source localization ability.