Dipole source localization by means of maximum likelihood estimation. II. Experimental evaluation.

A dipole source analysis of repeated measurements of the auditory evoked field (AEF) elicited by 60 dB SL tonebursts confirmed the previous theoretical prediction that a maximum likelihood estimation technique reduces localization errors resulting from noise in the measured data by about a factor of two as compared to the common least-squares fit procedure. To achieve a comparable improvement by averaging independent epochs (Gaussian noise assumed), the number of averages would have to be increased by a factor of 4. Conversely, the measurement time required to achieve a given localization accuracy could be reduced by that factor.