Abstract
Independent component analysis (ICA) has been extensively applied to reject artifacts in electroencephalography (EEG) signal processing. The first step is to extract the independent component activations from the electrode records, and then project the desired components back to the electrodes. After the composition of the projected component is analyzed in details under ICA procedure, this study shows that since ICA may extract some source components at the local optimization in high-dimensional EEG signal space, the artificial polarity indeterminacy may happen on the projected component at some electrodes. By numerical simulations, this issue also exhibits that this polarity ambiguity occurs. Hence, we conclude that the abnormal polarity reversal should be corrected, and that without prior knowledge on the desired target activation or the artifacts, the polarity of the projected component may be not reliable under ICA procedure.
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References
Makeig, S., Bell, A. J., Jung, T.P., et al.(1996) Independent component analysis of electroencephalographic data. In D. Touretzky, M. Mozer, & M. Hasselmo (Eds.), Advances in Neural Information Processing Systems, Cambridge, MA, USA: MIT Press, 8: 145–151
Makeig, S., Westerfield, M., Jung, T.P., et al. (1999) Functionally independent components of the late positive event-related potential during visual spatial attention. Journal of Neuroscience, 19: 2665–2680.
Delorme A., Makeig S. (2004) EEGLAB: an open source toolbox for analysis of single-trial EEG dynamics. Journal of Neuroscience Methods, Vol.134, pp.9–21.
Comon P.(1994) Independent component analysis, a new concept?. Signal processing, 36(3):287–314.
Himberg J., Hyvärinen A., Esposito F.(2004) Validating the independent components of neuroimaging time-series via clustering and visualization. NeuroImage, 22(3):1214–1222.
Näätänen, R. (1992) Attention and brain function, Hillsdale, NJ: Lawrence Erlbaum Associates Publishers.
Harmony T. (1984) Neurometric assessment of brain dysfunction in neurological patients. In E. R. John & R. W. Thatcher (Eds.). Functional Neuroscience: Vol. III. Hillsdale, NJ: Lawrence Erlbaum Associates Publishers.
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© 2008 Springer-Verlag Berlin Heidelberg
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Cong, F., Kalyakin, I., Ristaniemi, T., Lyytinen, H. (2008). Drawback of ICA Procedure on EEG: Polarity Indeterminacy at Local Optimization. In: Katashev, A., Dekhtyar, Y., Spigulis, J. (eds) 14th Nordic-Baltic Conference on Biomedical Engineering and Medical Physics. IFMBE Proceedings, vol 20. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-69367-3_55
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DOI: https://doi.org/10.1007/978-3-540-69367-3_55
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-69366-6
Online ISBN: 978-3-540-69367-3
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