Abstract
Scalp recording of electrical events allows evaluation of human cerebral function, but contributions of the specific brain structures generating the recorded activity are ambiguous. This problem is ill-posed and cannot be solved without auxiliary physiological knowledge about the spatio-temporal characteristics of the generators’ activity. The widely-used model to describe the evoked potentials’ sources is a set of current dipoles. It does not include a temporal model of source activity and does not propose a solution of the number of sources that are active simultaneously nor how to differentiate their contributions.
In our multichannel wavelet-type decomposition, scalp recorded signals are decomposed into a combination of physiologically-based wavelets. The coherent activity of a population of neurons may be derived by convolving a single cell’s electrical contribution with the population’s Gaussian temporal distribution of activity. Thus, we chose the Hermite Functions (derived from the Gaussian function to form mono-, bi- and tri-phasic waveforms) as the mathematical model to describe the temporal pattern of mass neural activity.
For each wavelet we solve the inverse problem for two symmerically positioned and oriented dipoles, one of which attains zero magnitude when a single source is more suitable. We use the wavelet to model the temporal activity pattern of the symmetrical dipoles. By this we reduce the dimension of inverse problem and find a plausible solution. Once the number and the initial parameters of the sources are given, we can apply multiple source estimation to correct the solution for generators with overlapping activity.
Application of the procedure to subcortical and cortical components of short-latency visual evoked potentials (SVEP) in response to high-intensity, strobe flashes, demonstrates its feasibility.
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References
Achim. A., Richer, F.. Saint-Hilaire, J.M.,1991, Methodological considerations for the evaluation of Spatio-Temporal Source Models (STAM). Electroenceph. Clin. Neurophysiol., 79: 227–240.
Allison. G., Goff. W. R.. Williamson, P.D.. and Van Gilder. J. C., 1980, On the neural origin of early components of the human somatosensory evoked potential. In Desmedt J.E. (ed.): Clinical Uses of Cerebral. Brainstem and Spinal Somatosensory Evoked Potentials. Progress in Clinical Neurophysiology.
Basel, Karger. 7: 51-68. Daubechies. L, 1988, Orthogonal bases of compactly supported wavelets, Commun. Pure Appl. Math. 41: 909-996.
Donchin, E., 1980, Event-related brain potentials: a tool in the study of human information processing. In: Begleiter H. (ed.) Evoked Potentials in Psychiatry. Plenum, New York.
Duffy, F. H.. 1982, Topographic display of evoked potentials: clinical applications of brain electrical activity mapping (BEAM) evoked potentials, Ann. NY.Acad. Sci. 388: 183–198.
Fender, D. H.. 1987, Source localization of brain electrical activity. In: Gevins, A. S, and Remond, A. (eds.), Methods of Analysis of Brain Electrical and Magnetic Signals. Handbook of Electroencephalographv and Clinical Neurophysiology. Elsevier, Amsterdam, Vol. 1, 13: 355–403.
Gath, I.. and Geva, A. B., 1989. Unsupervised optimal fuzzy clustering. IEEE Trans. Pattern Anal. Machine Intel. 7: 773–781.
Genossar, T., and Porat, M., 1992, Optimal bi-orthonormal approximation of signals. IEEE Trans. on Systems, Man, and Cybernetics 22 (3): 449.
Geva, A. B., Pratt H., and Zeevi Y. Y., 1993, WaveletDecomposition of multichannel evoked potential s, Electroenceph. Clin. Neurophysiol. 87: S25.
Geva, A. B., Pratt, H., 1994, Unsupervised clustering of evoked potentials by waveform, Med. & Biol. Eng. & Comput. 32: 543–550.
Geva. A. B., Pratt. H., and Zeevi, Y Y., 1995, Spatio-temporal multiple source localization by wavelet-type decomposition of evoked potentials. Electroenceph. Clin. Neurophysiol. In press.
Lehmann. D., 1987, Principles of spatial analysis. In: Gevins,A. S, and Remond. A. (eds.), Methods of Analysis of Brain Electrical and Magnetic Signals. Handbook of Electroencephalographv and Clinical Neurophysiology. Elsevier: Amsterdam, vol. 1, 12: 309–354.
Mallat, S. Ci., 1989, A theory for multiresolution signal decomposition: the wavelet representation, IEEE Trans. on Pattern Analysis and Machine Intelligence 11:674-693.
McGillem, C. D., and Aunon, J. L, 1987, Analysis of event-related potentials. In: Gevins, A. S.. and Remond, A. (eds.), Methods and Analysis ofBrain Electrical and Magnetic Signals. Handbook ofElectroencephalographv and Clinical Neurophysiology. Elsevier: Amsterdam. vol. 1, 5. 131- I 69.
Moller, A. R., Jannetta, P. J., and Jho, H. D., 1990, Recordings from human dorsal column nuclei using stimulation of the lower limb, Neurosurgery 26: 291–299.
Morioka, T., Shima, F., Kato, M., and Fukui, M., 1991, Direct recording of somatosensory evoked potentials in the vicinity of the dorsal column nuclei in man: their generator mechanisms and contribution to the scalp far-field potentials, Electroenceph. Clin. Neurophysiol. 80: 215–220.
Morton, J., Marcus, S., and Frankish, C., 1976, Perceptual centers (P-centers), Psychol. Rev. 83: 405–408.
Mosher, J. C., Lewis, P. S., and Leahy, R. M., 1992, Multiple dipole modeling and localization from spatio-temporal MEG data, IEEE Trans. on Biomed. Eng. 39: 541–557.
Nunez, P.L., 1981, Electric Fields of the Brain. The Neurophysics ofEEG. Oxford: New York.
Papakostopolous, D. A., and Crow, H. J., 1980, Direct recording of the somatosensory evoked potentials from the cerebral cortex of man and the difference between precentral and postcentral potentials. In Desmedt, J.E. (ed.): Clinical Uses of Cerebral, Brainstem and Spinal Somatosensory Evoked Potentials. Progress in Clinical Neurophysiology. Karger:Basel, 7: 15–26.
Plonsey, R., and Fleming, D. G., 1969, Bioelectric Phenomena. McGraw-Hill: New York. 5: 203-275.
Porat, M., and Zeevi, Y. Y., 1988, The generalized Gabor scheme of image representation in biological and machine vision, IEEE Trans. Pattern Anal. Machine Intel. 10: 452–468.
Pratt, H., Michalewski, H. J., Barrett, G., and Starr, A., 1989, Brain potentials in a memory-scanning task: I. Modality and task effects on potentials to probes, Electroenceph. Clin. Neurophysiol. 72: 407–42 I.
Pratt, H.. Martin, W. H., Bleich, N., Zaaroor, M., and Schacham, S. E., 1994, A high intensity, goggle-mounted flash stimulator for short latency visual evoked potentials. Electroenceph. Clin. Neurophysiol. 92: 469–472.
Regan, D., 1989, Human Brain Electrophysiology. Evoked Potentials und Evoked Magnetic Fields in Science and Medicine. Elsevier: Amsterdam, pp. 57–66.
Rioul, O., and Duhamel, P., 1992. Fast algorithms for discrete and continuous wavelet transforms, IEEE Trans. Inform. Theory 1T38: 569–586.
Scherg, M.. and von Cramon. D., 1985. A new interpretation of the generators of BAEP waves I-V. Results of spatio-temporal dipole model, IEEE Trans. Inform. Theory IT62: 290–299.
Slimp. J. C., Minas, L. B., Stolov, W. C., and Wyler, A. R., 1985. Somatosensory evoked potentials after removal of somatosensory cortex. Electroenceph. Clin. Neurophysiol. 37: 663–669.
Tichonov, A. N., and Arsenin, V. Y., 1977, Solution of Ill-Posed Problems. Wiley: New York.
Urasaki, E., Wada, S., Kadoya, C., Yokota, A., Matsuoka, S., and Shima, F.,1990, Origin of scalp far-field NJ 8 of SSEPs in response to median nerve stimulation, Electroenceph. Clin. Neurophysiol. 77:39-5 I.
Urasaki, E., Uematsu, S., and Lesser, R. P., 1993, Short latency somatosensory evoked potentials recorded around the human upper brainstem, Electroenceph. Clin. Neurophysiol. 88:92-104.
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Geva, A.B., Pratt, H., Zeevi, Y.Y. (1996). Spatio-Temporal Source Estimation of Evoked Potentials by Wavelet-Type Decomposition. In: Gath, I., Inbar, G.F. (eds) Advances in Processing and Pattern Analysis of Biological Signals. Springer, Boston, MA. https://doi.org/10.1007/978-1-4757-9098-6_8
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DOI: https://doi.org/10.1007/978-1-4757-9098-6_8
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