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Signal-space projection method for separating MEG or EEG into components

  • M. A. Uusitalo
  • R. J. Ilmoniemi
Communication

Keywords

Brain mapping Electroencephalography Equivalent current dipole Functional imaging Inverse problem Magnetoencephalography Signal-space projection Source analysis 

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References

  1. Ahlfors, S. P., Ilmoniemi, R. J., andHämäläinen, M. S. (1992): ‘Estimates of visually evoked cortical currents’,Electroenceph. Clin. Neurophysiol.,82, pp. 225–236CrossRefGoogle Scholar
  2. Ahonen, A. I., Hämäläinen, M. S., M. S., Kajola, M. J., Knuutila, J. E. T., Laine, P. P., Lounasmaa, O. V., Parkkonen, L. T. Simola, J. T. andTesche, C. D. (1993): ‘122-channel SQUID instrument for investigating the magnetic signals from the human brain’,Physica Scripta T49, pp. 198–205Google Scholar
  3. Berg, P., andScherg, M. (1994): ‘A multiple source approach to the correction of eye artifacts’Electroenceph. Clin. Neurophysiol.,90, pp. 229–241CrossRefGoogle Scholar
  4. Desmedt, J. E., andCalklin, V. (1989): ‘New method for titrating differences in scalp topographic patterns in brain evoked potential mapping,’Ibid.,,74, pp. 359–366CrossRefGoogle Scholar
  5. Gordnitsky, I. F., George, J. S., andRao, B. D. (1995): ‘Neuromagnetic source imaging with FOCUSS: a recursive weighted minimum norm algorithm,’Ibid.,95, pp. 231–251CrossRefGoogle Scholar
  6. Grummich, P., Vieth, J., andKober, H. (1991): ‘Magnetic fields of the brain analysed by a multiple dipole approach using factor analysis,’Clin. Phys. Physiol. Meas.,12 (Suppl. A), pp. 61–66Google Scholar
  7. Hämäläinen, M. S., andIlmoniemi, R. J. (1994): ‘Interpreting magnetic fields of the brain: minimum norm estimates,’Med. Biol. Eng. Comput.,32, pp. 35–42Google Scholar
  8. Hämäläinen, M. S. (1995): ‘Functional localization based on measurements with a whole-head magnetometer system,’Brain Topog.,7, pp. 283–289CrossRefGoogle Scholar
  9. Harris, R. J. (1975): ‘A primer of multivariate statistics’ (Academic Press, New York).zbMATHGoogle Scholar
  10. Helmholtz, H. von (1853): ‘Ueber einige Gesetze der Vertheilung elektrischer Ströme in Körperlichen Leitern, mit Anwendung auf die thierisch-elektrischen Versuche,’Ann. Phys. Chem.,89, pp. 211–233, 353–377Google Scholar
  11. Huotilainen, M., Ilmoniemi, R. J., Tiitinen, H., Lavikainen, J., Alho, K., Kajola, M., Simola, J., andNäätänen, R. (1993): ‘Eye-blink removal for multichannel MEG measurements’in Deecke, L., Baumgartner, C., Stroink G., andWilliamson, S. J. (Eds.): Abstracts of Int. Conf. on Biomagnetism, Vienna, Austria, 14–20 August, pp. 209–210Google Scholar
  12. Ilmoniemi, R. (1981): ‘7-channel SQUID magnetometer for brain research’. MSc Thesis, Department of Technical Physics, Helsinki University of TechnologyGoogle Scholar
  13. Ilmoniemi, R. J., andWilliamson, S. J. (1987): ‘Analysis of the magnetic alpha rhythm in signal space,’Soc. Neurosci. Abstr.,13, p. 46Google Scholar
  14. Ilmoniemi, R. J., Williamson, S. J., andHostetler, W. E. (1987): ‘New method for the study of spontaneous brain activity’,in Atsumi, K., Kotani, M., Ueno, S., Katila, T., andWilliamson, S. J. (Eds.). Biomagnetism 87 (Tokyo Denki University Press, Tokyo) pp. 182–185Google Scholar
  15. Ilmoniemi, R. J. (1992): ‘Method and apparatus for separating the different components of evoked response and spontaneous activity brain signals as well as signals measured from the heart. Finnish patent application 925461, 30 NovemberGoogle Scholar
  16. Ilmoniemi, R. J. (1993): ‘Method and apparatus for separating the different components of evoked response and spontaneous activity brain signals as well as signals measured from the heart’. International patent application PCT/F193/00504, 30 NovemberGoogle Scholar
  17. Jousmäki, V., andHari, R. (1996): ‘Cardiac artifacts in magnetoencephalogram’,J. Clin Neurophysiol.,13, pp. 172–176CrossRefGoogle Scholar
  18. Knuutila, J. E. T., Ahonen, A. I., Hämäläinen, M. S., Kajola, M. J., Laine, P. P., Lounasmaa, O. V., Parkkonen, L. T., Simola, J. T. A., andTesche, C. D. (1993): ‘A 122-channel whole-cortex SQUID system for measuring the brain's magnetic fields,’IEEE Trans.,MAG-29, pp. 3315–3320Google Scholar
  19. Koles, Z. J., Lazar, M. S., andZhou, Z. (1990): ‘Spatial patterns underlying population differences in the background EEG’,Brain Topog.,2, pp. 275–284CrossRefGoogle Scholar
  20. Koles, Z. J. (1991): ‘The quantitative extraction and topographic mapping of the abnormal components in the clinical EEG,’Electroenceph. Clin. Neurophysiol.,79, pp. 440–447CrossRefGoogle Scholar
  21. Lütkenhöner, B. (1992): ‘Frequency-domain localization of intracerebral dipolar sources,’Ibid.,82, pp. 112–118CrossRefGoogle Scholar
  22. Lütkenhöner, B., Pantev, C., Grunvald, A., andMenninghaus, E. (1993): ‘Source-space projection of single trials of the auditory evoked field’,in Deecke, L., Baumgartner, C., Stroink, G., andWilliamson, S. J. (Eds.): Abstract of Int. Conf. on Biomagnetism, Vienna, Austria, 14–20 August, pp. 203–204.Google Scholar
  23. Maier, J., Dagnelie, G., Spekreijse, H., andVan Duk, B. W. (1987): ‘Principal components analysis for source localization of VEPs in man,’Vision Res.,27, pp: 165–177CrossRefGoogle Scholar
  24. Miettinen, M. (1992): ‘Magnetic measurements of visually evoked responses’. MSc Thesis, Department of Technical Physics, Helsinki University of TechnologyGoogle Scholar
  25. Mosher, J. C., Lewis, P. S., andLeahy, R. M. (1992): ‘Multiple dipole modeling and localization from spatio-temporal MEG data,’IEEE Trans.,BME-39, pp. 541–557Google Scholar
  26. Pascual-Marqui, R. D., Michel, C. M., andLehmann, D. (1994): ‘Low resolution electromagnetic tomography: a new method for localizing electrical activity in the brain,’Int. J. Psychophys.,18, pp. 49–65CrossRefGoogle Scholar
  27. Robinson, S. E., andRose, D. F. (1992): ‘Current source image estimation by spatially filtered MEG’in Hoke, M., Erné, S. N., Okada, Y. C., andRomani, G. L. (Eds.): ‘Biomagnetism: clinical aspects’ (Elsevier, Amsterdam) pp. 761–765Google Scholar
  28. Salmelin, R. H., andHämäläinen, M. S. (1995): ‘Dipole modelling of MEG rhythms in time and frequency domains,’Brain Topog.,7, pp. 251–257CrossRefGoogle Scholar
  29. Salmelin, R., Hämäläinen, M., Kajola M., andHari, R. (1995): ‘Functional segregation of movement-related rhythmic activity in the human brain,’Neuroimage,2, pp. 237–243CrossRefGoogle Scholar
  30. Scherg, M. (1990): ‘Fundamentals of dipoles source potential analysis’in Grandori, F., Hoke, M., andRomani, G. L. (Eds.): ‘Auditory evoked magnetic fields and electric potentials’ (Karger, Basel), pp. 40–69Google Scholar
  31. Soong, A. C. K., andKoles, Z. J. (1995): ‘Principal-component localization of the sources of the background EEG,’IEEE Trans.,BME-42, pp. 59–67Google Scholar
  32. Tesche, C., andKajola, M. (1993): ‘A comparison of the localization of spontaneous neuromagnetic activity in the frequency and time domains,’Electronceph. Clin. Neurophysiol.,87, pp. 408–416CrossRefGoogle Scholar
  33. Tesche, C. D., Uusitalo, M. A., Ilmoniemi, R. J., Huotilainen, M., Kajola, M., andSalonen, O. (1995a) ‘Signal-space projections of MEG data characterize both distributed and well-localized neuronal sources,’Electroenceph. Clin. Neurophysiol.,95, pp. 189–200CrossRefGoogle Scholar
  34. Tesche, C. D., Uusitalo, M. A., Ilmoniemi, R. J., andKajola, M. J. (1995b): ‘Characterizing, the local oscillatory content of spontaneous cortical activity during mental imagery,’Cogn. Brain Res.,2, pp. 243–249CrossRefGoogle Scholar
  35. Uusitalo, M. A. (1993): ‘Projection method in magnetoencephalography’, MSc Thesis, Department of Technical Physics, helsinki University of TechnologyGoogle Scholar
  36. Uusitalo, M. A., Ilmoniemi, R. J., andTesche, C. D. (1994): ‘The signal-space projection (SSP) method. Abstracts of 5th Int. Congress of Int. Society for Brain Electromagnetic Topography’ Münster, Germany, 2–6 August, p. 60Google Scholar
  37. Wang, J.-Z., Williamson, S. J., andKaufman, L. (1995): ‘Kinetic images of neuronal activity of the human brain based on the spatiotemporal MNLS inverse: a theoretical study,’Brain Topog.,7, pp. 193–200CrossRefGoogle Scholar

Copyright information

© IFMBE 1997

Authors and Affiliations

  • M. A. Uusitalo
    • 1
  • R. J. Ilmoniemi
    • 2
  1. 1.Brain Research Unit, Low Temperature LaboratoryHelsinki University of TechnologyEspooFinland
  2. 2.BioMag Laboratory, Medical Engineering CentreHelsinki University Central Hospital, 00290HelsinkiFinland

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