Abstract
Magnetoencephalography (MEG) is a noninvasive neuroimaging tool that offers a combination of excellent temporal and good spatial resolution, provided that the acquired signals have a high-enough signal-to-noise ratio. This requirement is often compromised as MEG signals are very weak and often masked by interfering signals from environmental noise sources present at most MEG sites. Even more challenging interference is encountered if the subject carries any magnetic material attached to the body, which is sometimes inevitable in clinical settings, e.g., due to therapeutic stimulators. Therefore, to enable reliable data analysis, it is very important to reduce the contribution of noise in MEG signals as efficiently as possible. In this chapter, we review the basic characteristics of MEG signals, give a short review on traditional approaches to suppress noise, and describe some examples of modern noise reduction methods. Specifically, we emphasize the usefulness of advanced mathematical algorithms applied on the multichannel MEG data.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Adjamian P, Worthen S, Hillebrand A, Furlong P, Chizh B, Hobson A, Aziz Q, Barnes G (2009) Effective electromagnetic noise cancellation with beamformers and synthetic gradiometry in shielded and partly shielded environments. J Neurosci Methods 178(1):120–127
Ahonen A, Hämäläinen M, Ilmoniemi R, Kajola M, Knuutila J, Simola J, Vilkman V (1993) Sampling theory for neuromagnetic detector arrays. IEEE Trans Biomed Eng 40:859–869
Airaksinen K, Mäkelä J, Taulu S, Ahonen A, Nurminen J, Schnitzler A, Pekkonen E (2011) Effects of DBS on auditory and somatosensory processing in Parkinson’s disease. Hum Brain Mapp 32(7):1091–1099
Arfken G (1985) Mathematical methods for physicists. Academic, San Diego
Bork J, Hahlbohm HD, Klein R, Schnabel A (2001) The 8-layered magnetically shielded room of the PTB: design and construction. In: Jukka, Risto, Toivo (eds) Biomag2000. Proceedings of the 12th international conference on biomagnetism. Helsinki University of Technology, Espoo, Finland 2000, pp 970–973
Cardoso J (1998) Blind signal separation: statistical principles. Proc IEEE 86:2009–2025
Carrette E, De Tiège X, Op De Beeck M, De Herdt V, Meurs A, Legros B, Raedt R, Deblaere K, Van Roost D, Bourguignon M, Goldman S, Boon P, Van Bogaert P, Vonck K (2011) Magnetoencephalography in epilepsy patients carrying a vagus nerve stimulator. Epilepsy Res 93(1):44–52
Chella F, Zappasodi F, Marzetti L, Della Penna S, Pizzella V (2012) Calibration of a multichannel MEG system based on the signal space separation method. Phys Med Biol 57(15):4855–4870
Clarke J, Braginski A (eds) (2006) The SQUID handbook. Wiley-VCH, Weinham
Cohen D (1968) Magnetoencephalography: evidence of magnetic fields produced by alpha-rhythm current. Science 161:784–786
Cohen D (1970) Large-volume conventional magnetic shields. Rev Phys Appl 5:53–58
Cohen D (1972) Magnetoencephalography: detection of the brain’s electrical activity with a superconducting magnetometer. Science 175:664–666
Cohen D (1979) Magnetic measurement and display of current generators in the brain. Part I: the 2-d detector. In: Proceedings of the 12th international conference on medical and biological engineering. Beilinson Medical Center, Petah Tikva, Israel, Jerusalem, pp 15–16
De Cheveigné A (2010) Time-shift denoising source separation. J Neurosci Methods 189(1):113–120
De Cheveigné A, Simon J (2007) Denoising based on time-shift PCA. J Neurosci Methods 165:297–305
De Cheveigné A, Simon J (2008) Sensor noise suppression. J Neurosci Methods 168(1):195–202
De Tiège X, Op de Beeck M, Funke M, Legros B, Parkkonen L, Goldman S, Van Bogaert P (2008) Recording epileptic activity with MEG in a light-weight magnetic shield. Epilepsy Res 82(2–3):227–231
Gross J, Baillet S, Barnes G, Henson R, Hillebrand A, Jensen O, Jerbi K, Litvak V, Maess B, Oostenveld R, Parkkonen L, Taylor J, van Wassenhove V, Wibral M, Schoffelen J (2013) Good practice for conducting and reporting MEG research. Neuroimage 65:349–363
Hall Barbosa C, Andrade Lima E, Bruno A, Ewing A, Wikswo JP Jr (1999) Flux/voltage calibration of axial SQUID gradiometers using an optimization procedure. IEEE Trans App Supercond 9:3523–3526
Hämäläinen M, Hari R, Ilmoniemi RJ, Knuutila J, Lounasmaa OV (1993) Magnetoencephalography—theory, instrumentation, and applications to noninvasive studies of the working human brain. Rev Mod Phys 65:413–498
Helle L, Parkkonen L, Taulu S. Ahonen A (2012) Suppression of uncorrelated sensor noise and artifacts: demonstration with high frequency brain signals. Abstracts of the 18th international conference on biomagnetism, Paris 2012, p 284
Hill E (1954) The theory of vector spherical harmonics. Am J Phys 22:211–214
Hillebrand A, Pazio P, de Munck J, van Dijk B (2013) Feasibility of clinical magnetoencephalography (MEG) functional mapping in the presence of dental artefacts. Clin Neurophysiol 124(1):107–113
Hyvärinen A (1999) Fast and robust fixed-point algorithms for independent component analysis. IEEE Trans Neural Netw 10:626–634
Hyvärinen A, Ramkumar P, Parkkonen L, Hari R (2010) Independent component analysis of short-time Fourier transforms for spontaneous EEG/MEG analysis. Neuroimage 49:257–271
Ilmoniemi R (1981) 7-channel SQUID magnetometer for brain research. M.Sc. thesis, Helsinki University of Technology
Ilmoniemi R, Williamson S (1987) Analysis of the magnetic alpha rhythm in signal space. Soc Neurosci Abstr 13:46
Ilmoniemi R, Williamson S, Hostetler W (1987) New method for the study of spontaneous brain activity, Biomagnetism 87. Tokyo Denki University Press, Tokyo, pp 182–185
Jackson J (1999) Classical electrodynamics. Wiley, New York
Kakisaka Y, Mosher J, Wang Z, Jin K, Dubarry A, Alexopoulos A, Burgess R (2012) Utility of temporally-extended signal space separation algorithm for magnetic noise from vagal nerve stimulators. Clin Neurophysiol, 124(7)
Karp E, Parkkonen L, Vigário R (2009) Denoising single trial event related magnetoencephalographic recordings. In: Adali T et al (eds) Independent component analysis and signal separation. Springer, Berlin, pp 427–434
Kelhä V, Pukki J, Peltonen R, Penttinen A, Ilmoniemi R, Heino J (1982) Design, construction, and performance of a large-volume magnetic shield. IEEE Trans Magn MAG 18:260–270
Kiviranta M, Seppä H (1995) DC-SQUID electronics based on the noise cancellation scheme. IEEE Trans Appl Supercond 5(2):2146–2148
Kominis I, Kornack T, Allred J, Romalis M (2003) A subfemtotesla multichannel atomic magnetometer. Nat Lond 422:596
Mosher J, Hämäläinen M, Pantazis D, Hui H, Burgess R, Leahy R (2009) Generalized sidelobe canceller for magnetoencephalography arrays. Proc IEEE Int Symp Biomed Imaging 2009:149–152
Nenonen J, Montonen J, Katila T (1996) Thermal noise in biomagnetic measurements. Rev Sci Instr 67(6):2397–2405
Nenonen J, Kajola M, Simola J, Ahonen A (2004) Total information of multichannel MEG sensor arrays. Proceedings of the 14th international conference on biomagnetism. Biomag Ltd, Boston, pp 630–631
Nenonen J, Taulu S, Kajola M, Ahonen A (2007) Total information extracted from MEG measurements. Int Congr Ser 1300:245–248
Nenonen J, Nurminen J, Kičić D, Bikmullina R, Lioumis P, Jousmäki V, Taulu S, Parkkonen L, Putaala M, Kähkönen S (2012) Validation of head movement correction and spatiotemporal signal space separation in magnetoencephalography. Clin Neurophysiol 123(11):2180–2191
Nurminen J, Taulu S, Okada Y (2008) Effects of sensor calibration, balancing and parametrization on the signal space separation method. Phys Med Biol 53(7):1975–1987
Öisjöen F, Schneiderman J, Figueras G, Chukharkin M, Kalabukhov A, Hedström A, Elam M, Winkler D (2012) High-Tc superconducting quantum interference device recordings of spontaneous brain activity: towards high-Tc magnetoencephalography. Appl Phys Lett 100:132601
Ornelas P, Bruno A, Hall Barbosa C, Andrade Lima E, Costa Ribeiro P (2003) A survey of calibration procedures for SQUID gradiometers. Supercond Sci Technol 16:427–431
Pannetier M, Fermon C, Goff G, Simola J, Kerr E (2004) Femtotesla magnetic field measurement with magnetoresistive sensors. Science 304:1648–1650
Pannetier-Lecoeur M, Parkkonen L, Sergeeva-Chollet N, Polovy H, Fermon C, Fowley C (2011) Magnetocardiography with sensors based on giant magnetoresistance. Appl Phys Lett 98:153705
Parkkonen L, Salmelin R (2010) Ch3: Measurements. In: Hansen P, Kringelbach M, Salmelin R (eds) MEG: an introduction to methods. Oxford University Press, New York
Parkkonen L, Simola J, Tuoriniemi J, Ahonen A (1999a) An interference suppression system for multichannel magnetic field detector arrays. In: Yoshimoto T et al (eds) Recent advances in biomagnetism: proceedings of the 11th international conference on biomagnetism. Tohoku University Press, pp 13–16
Parkkonen L, Simola J, Kajola M, Hämäläinen M, Ahonen A (1999b) Experiments on interference suppression in MEG measurements. Abstracts of the human brain mapping conference, Düsseldorf 1999, #165
Parkkonen L, Simola J, Taulu S, Kajola M, Knuutila J, Kojo A, Laine P, Nenonen J, Ahonen A (2006) A light-weight magnetic shield: performance in real MEG measurements. Proceedings of the 15th International Conference on Biomagnetism, Vancouver, BC, Canada, 21–25 Aug 2006. Abstracts of the 15th International Conference on Biomagnetism, Vancouver 2006
Patton B, Fitch J (1962) Design of a room-size magnetic shield. J Geophys Res 67(3):1117
Ramirez R, Kopell B, Butson C, Hiner B, Baillet S (2011) Spectral signal space projection algorithm for frequency domain MEG and EEG denoising, whitening, and source imaging. Neuroimage 56(1):29–78
Ramkumar P, Parkkonen L, Hari R, Hyvärinen A (2012) Characterization of neuromagnetic brain rhythms over time scales of minutes using spatial independent component analysis. Hum Brain Mapp 33:1648–1662
Särelä J, Valpola H (2005) Denoising source separation. J Mach Learn Res 6:233–327
Sekihara K, Nagarajan S, Poeppel D, Marantz A (2004) Performance of an MEG adaptive-beamformer source reconstruction technique in the presence of additive low-rank interference. IEEE Trans Biomed Eng 51(1):90–99
Simola J (2003) Wall element for magnetically shielded room and magnetically shielded room. Patent WO/2003/059030
Simola J, Taulu S (2011) Method for designing coil systems for generation of magnetic fields of desired geometry. PCT/FI2011/050249
Simola J, Laine P, Rakkolainen H (2005) Joint structure between the wall elements of a magnetically shielded room. PCT/FI05/00385
Tanaka N, Thiele E, Madsen J, Bourgeois B, Stufflebeam S (2009) Magnetoencephalographic analysis in patients with vagus nerve stimulator. Pediatr Neurol 41(5):383–387
Tang A, Pearlmutter B, Malaszenko N, Phung D, Reeb B (2002) Independent components of magnetoencephalography: localization. Neural Comput 14:1827–1858
Taulu S (2000) M.Sc. thesis (in Finnish), Helsinki University of Technology
Taulu S (2008) Processing of weak magnetic multichannel signals: the signal space separation method. PhD dissertation, Helsinki University of Technology
Taulu S, Hari R (2009) Removal of magnetoencephalographic artifacts with temporal signal-space separation: demonstration with single-trial auditory-evoked responses. Hum Brain Mapp 30(5):1524–1534
Taulu S, Kajola M (2005) Presentation of electromagnetic multichannel data: the signal space separation method. J Appl Phys 97(124905):1–10
Taulu S, Simola J (2006) Spatiotemporal signal space separation method for rejecting nearby interference in MEG measurements. Phys Med Biol 51(7):1759–1768
Taulu S, Kajola M, Simola J (2004) Suppression of interference and artifacts by the signal space separation method. Brain Topogr 16(4):269–275
Taulu S, Simola J, Kajola M (2005) Applications of the signal space separation method. IEEE Trans Sign Proc 53:3359–3372
Taulu S, Simola J, Kajola M, Helle L, Ahonen A, Sarvas J (2012) Suppression of uncorrelated sensor noise and artifacts in multichannel MEG data. Abstracts of the 18th international conference on biomagnetism, Paris, 2012, p 285
Uusitalo M, Ilmoniemi R (1997) Signal-space projection method for separating MEG or EEG into components. Med Biol Eng Comput 35(2):135–140
Vesanen P, Nieminen J, Zevenhoven K, Dabek J, Parkkonen L, Zhdanov A, Luomahaara J, Hassel J, Penttilä J, Simola J, Ahonen A, Mäkelä J, Ilmoniemi R (2012) Hybrid ultra-low-field MRI and magnetoencephalography system based on a commercial whole-head neuromagnetometer. Magn Reson Med 67:1138–1145. (2012 Jul 17, epub ahead of print)
Vigario R, Särelä J, Jousmäki V, Hämäläinen M, Oja E (2000) Independent component approach to the analysis of EEG and MEG recordings. IEEE Trans Biomed Eng 47:589–593
von Helmholtz H (1853) Ueber einige Gesetze der Vertheilung elektrischer Ströme in körperlichen Leitern, mit Anwendung auf die thierisch-elektrischen Versuche. Ann Phys Chem 89(211–233):353–377
Vrba J, Robinson S (2001) Signal processing in magnetoencephalography. Methods 25:249–271
Vrba J, Robinson S (2002) SQUID sensor array configurations for magnetoencephalography applications. Supercond Sci Technol 15:R51–R89
Vrba J, Taulu S, Nenonen J, Ahonen A (2010) Signal space separation beamformer. Brain Topogr 23(2):128–133
Wikswo J (2004) SQUIDs remain best tools for measuring brain’s magnetic field. Phys Today 57(2):15
Zimmerman J, Frederick N (1971) Miniature ultrasensitive superconducting magnetic gradiometer and its use in cardiography and other applications. Appl Phys Lett 19:16
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Section Editor information
Rights and permissions
Copyright information
© 2019 Springer Nature Switzerland AG
About this entry
Cite this entry
Taulu, S., Simola, J., Nenonen, J., Parkkonen, L. (2019). Novel Noise Reduction Methods. In: Supek, S., Aine, C. (eds) Magnetoencephalography. Springer, Cham. https://doi.org/10.1007/978-3-030-00087-5_2
Download citation
DOI: https://doi.org/10.1007/978-3-030-00087-5_2
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-00086-8
Online ISBN: 978-3-030-00087-5
eBook Packages: Biomedical and Life SciencesReference Module Biomedical and Life Sciences