Effects of coherent noise on Ictal component selection for EEG source imaging

Abstract

This paper examines the effects of coherent noise on the scalp voltage topography, activity power spectra and dipole residual variances of the independent components (ICs) of ictal EEG signals. Eleven different sets of ictal EEG signals are generated by adding various amounts of coherent noises. All of these simulated EEGs are decomposed into their corresponding ICs. Single dipole source that helps to distinguish ictal components from noise components, two-dimensional (2D) topographic map, activity power spectrum, and dipole residual variance were estimated for each of these ICs. Topographic maps show that the number of ictal components decreases with the increase of noise level. Activity power spectrum analysis supports the result of topographic map analysis. The average residual variances not only increase with the increment of noise level but sometimes decrease as well. Simultaneous consideration of these three features is helpful for better selection of ictal components.