Multiple source localization using genetic algorithms

• Published in: Journal of neuroscience methods Vol. 64; no. 2; pp. 163 - 172
• Main Authors: McNay, D., Michielssen, E., Rogers, R.L., Taylor, S.A., Akhtari, M., Sutherling, W.W.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.1996; Elsevier Science
• Subjects: Algorithms; Biological and medical sciences; Brain - physiology; Computer Simulation; EEG; Electric Stimulation; Electrodes, Implanted; Electroencephalography; Electromagnetic Fields; Evoked Potentials - physiology; Fundamental and applied biological sciences. Psychology; General aspects. Models. Methods; Genetic algorithm; Humans; Models, Genetic; Multiple source localization; Reproducibility of Results; Spatio-temporal modeling; Vertebrates: nervous system and sense organs; Multiple source localization; Genetic algorithm; Spatio-temporal modeling; EEG; Methodology; Investigation method; Animal; Central nervous system; Electrophysiology; Dipole; Electroencephalography; Localization; Brain (vertebrata)
• ISSN: 0165-0270; 1872-678X
• DOI: 10.1016/0165-0270(95)00122-0

We present a new procedure for localizing simultaneously active multiple brain sources that overlap in both space and time on EEG recordings. The source localization technique was based on a spatio-temporal model and a genetic algorithm search routine. The method was successfully applied to the localization of two dipole sources from several sets of simulated potentials with various signal-to-noise ratios (SNR). The different SNR values resembled evoked responses and epileptic spikes as commonly seen in the laboratory. Results of the simulation studies yielded localization accuracy ranging from 0.01 to 0.07 cm with an SNR of 10; from 0.02 to 0.26 cm with an SNR of 5; and from 0.06 to 0.73 cm when the SNR was equal to 2. Additionally, two sets of simulations were based on the dipole arrangements and time activities of data obtained during electrical stimulation of the median nerve in human subjects. These studies yielded localization accuracy within 0.1 cm. We also studied the localization accuracy of the algorithm using a physical model incorporating potential measurements of two current dipoles embedded in a sphere. In this situation the algorithm was successful in localizing the two simultaneously active sources to within 0.07–0.15 cm.