{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T22:11:59Z","timestamp":1780524719717,"version":"3.54.1"},"reference-count":54,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,8,26]],"date-time":"2022-08-26T00:00:00Z","timestamp":1661472000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012190","name":"Ministry of Science and Higher Education of the Russian Federation","doi-asserted-by":"publisher","award":["075-15-2019-1623"],"award-info":[{"award-number":["075-15-2019-1623"]}],"id":[{"id":"10.13039\/501100012190","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002261","name":"Russian Foundation for Basic Research","doi-asserted-by":"publisher","award":["19-07-00964"],"award-info":[{"award-number":["19-07-00964"]}],"id":[{"id":"10.13039\/501100002261","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002261","name":"Russian Foundation for Basic Research","doi-asserted-by":"publisher","award":["20-07-00733"],"award-info":[{"award-number":["20-07-00733"]}],"id":[{"id":"10.13039\/501100002261","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002261","name":"Russian Foundation for Basic Research","doi-asserted-by":"publisher","award":["20-07-00842"],"award-info":[{"award-number":["20-07-00842"]}],"id":[{"id":"10.13039\/501100002261","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neural Circuits"],"abstract":"<jats:p>The article considers the problem of dividing the encephalography data into two time series, that generated by the brain and that generated by other electrical sources located in the human head. The magnetic encephalograms and magnetic resonance images of the head were recorded in the Center for Neuromagnetism at NYU Grossman School of Medicine. Data obtained at McGill University and Montreal University were also used. Recordings were made in a magnetically shielded room and the gradiometers were designed to suppress external noise, making it possible to eliminate them from the data analysis. Magnetic encephalograms were analyzed by the method of functional tomography, based on the Fourier transform and on the solution of inverse problem for all frequencies. In this method, one spatial position is assigned to each frequency component. Magnetic resonance images of the head were evaluated to annotate the space to be included in the analysis. The included space was divided into two parts: \u00abbrain\u00bb and \u00abnon-brain\u00bb. The frequency components were classified by the feature of their inclusion in one or the other part. The set of frequencies, designated as \u00abbrain\u00bb, represented the partial spectrum of the brain signal, while the set of frequencies designated as \u00abnon-brain\u00bb, represented the partial spectrum of the physiological noise produced by the head. Both partial spectra shared the same frequency band. From the partial spectra, a time series of the \u00abbrain\u00bb area signal and \u00abnon-brain\u00bb area head noise were reconstructed. Summary spectral power of the signal was found to be ten times greater than the noise. The proposed method makes it possible to analyze in detail both the signal and the noise components of the encephalogram and to filter the magnetic encephalogram.<\/jats:p>","DOI":"10.3389\/fncir.2022.834434","type":"journal-article","created":{"date-parts":[[2022,8,26]],"date-time":"2022-08-26T04:52:55Z","timestamp":1661489575000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":9,"title":["Splitting of the magnetic encephalogram into \u00abbrain\u00bb and \u00abnon-brain\u00bb physiological signals based on the joint analysis of frequency-pattern functional tomograms and magnetic resonance images"],"prefix":"10.3389","volume":"16","author":[{"given":"Rodolfo R.","family":"Llin\u00e1s","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stanislav","family":"Rykunov","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kerry D.","family":"Walton","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Boyko","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mikhail","family":"Ustinin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2022,8,26]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"669","DOI":"10.1109\/77.919433","article-title":"Reduction of non-periodic environmental magnetic noise in MEG measurement by continuously adjusted least squares method.","volume":"11","author":"Adachi","year":"2001","journal-title":"IEEE Trans. Appil. Superconduct."},{"key":"B2","doi-asserted-by":"publisher","first-page":"434","DOI":"10.1109\/78.554307","article-title":"A blind source separation technique using second-order statistics.","volume":"45","author":"Belouchrani","year":"1997","journal-title":"IEEE Trans. Signal Process."},{"key":"B3","article-title":"The 8-layered magnetically shielded room of the PTB: design and construction","author":"Bork","year":"2000","journal-title":"Biomagnetism: Proceedings of the 12th International Conference on Biomagnetism"},{"key":"B4","doi-asserted-by":"publisher","first-page":"405","DOI":"10.1109\/tbme.2013.2280143","article-title":"A constrained ICA approach for real-time cardiac artifact rejection in magnetoencephalography.","volume":"61","author":"Breuer","year":"","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"B5","doi-asserted-by":"publisher","first-page":"105","DOI":"10.1016\/j.jneumeth.2014.06.016","article-title":"Ocular and cardiac artifact rejection for real-time analysis in MEG.","volume":"233","author":"Breuer","year":"","journal-title":"J. Neurosci. Methods"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1016\/j.jneumeth.2020.108700","article-title":"Effectively combining temporal projection noise suppression methods in magnetoencephalography.","volume":"341","author":"Clarke","year":"2020","journal-title":"J. Neurosci. Methods"},{"key":"B7","first-page":"919","article-title":"New six-layer magnetically-shielded room for MEG","author":"Cohen","year":"2002","journal-title":"Proceedings of the 13th International Conference on Biomagnetism, jena, Germany"},{"key":"B8","doi-asserted-by":"publisher","first-page":"331","DOI":"10.1016\/j.jneumeth.2008.03.015","article-title":"Denoising based on spatial filtering.","volume":"171","author":"de Cheveign\u00e9","year":"","journal-title":"J. Neurosci. Methods"},{"key":"B9","doi-asserted-by":"publisher","first-page":"195","DOI":"10.1016\/j.jneumeth.2007.09.01","article-title":"Sensor noise suppression.","volume":"168","author":"de Cheveign\u00e9","year":"","journal-title":"J. Neurosci. Methods"},{"key":"B10","doi-asserted-by":"publisher","first-page":"968","DOI":"10.1016\/j.neuroimage.2006.01.021","article-title":"An automated labeling system for subdividing the human cerebral cortex on MRI scans into gyral based regions of interest.","volume":"31","author":"Desikan","year":"2006","journal-title":"Neuroimage"},{"key":"B11","doi-asserted-by":"publisher","first-page":"2274","DOI":"10.1007\/s10439-011-0312-7","article-title":"Quantitative evaluation of artifact removal in real magnetoencephalogram signals with blind source separation.","volume":"39","author":"Escudero","year":"2011","journal-title":"Ann. Biomed. Eng."},{"key":"B12","doi-asserted-by":"publisher","first-page":"1965","DOI":"10.1109\/tbme.2007.894968","article-title":"Artifact removal in magnetoencephalogram background activity with independent component analysis.","volume":"54","author":"Escudero","year":"2007","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"B13","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1093\/cercor\/bhg087","article-title":"Automatically parcellating the human cerebral cortex.","volume":"14","author":"Fischl","year":"2004","journal-title":"Cereb. Cortex"},{"key":"B14","doi-asserted-by":"publisher","first-page":"69","DOI":"10.1016\/j.neuroimage.2004.07.016","article-title":"Sequence-independent segmentation of magnetic resonance images.","volume":"23","author":"Fischl","year":"2004","journal-title":"Neuroimage"},{"key":"B15","doi-asserted-by":"publisher","first-page":"216","DOI":"10.1109\/JPROC.2004.840301","article-title":"The design and implementation of FFTW3.","volume":"93","author":"Frigo","year":"2005","journal-title":"Proc. IEEE"},{"key":"B16","doi-asserted-by":"publisher","first-page":"374","DOI":"10.1007\/978-3-319-66179-7_43","article-title":"Using convolutional neural networks to automatically detect eye-blink artifacts in magnetoencephalography without resorting to electrooculography.","volume":"1043","author":"Garg","year":"2017","journal-title":"Med. Image Comput. Comput. Assist. Intervent."},{"key":"B17","doi-asserted-by":"publisher","first-page":"189","DOI":"10.1016\/j.neuron.2019.07.001","article-title":"Magnetoencephalography in cognitive neuroscience: a primer.","volume":"104","author":"Gross","year":"2019","journal-title":"Neuron"},{"key":"B18","doi-asserted-by":"crossref","first-page":"23772","DOI":"10.1073\/pnas.1913092116","article-title":"The generation and propagation of the human alpha rhythm.","volume":"116","author":"Halgren","year":"2019","journal-title":"Proc. Natl. Acad. Sci. U.S.A."},{"key":"B19","doi-asserted-by":"publisher","first-page":"413","DOI":"10.1103\/revmodphys.65.413","article-title":"Magnetoencephalography\u2014theory, instrumentation, and applications to noninvasive studies of the working human brain.","volume":"65","author":"H\u00e4m\u00e4l\u00e4inen","year":"1993","journal-title":"Rev. Modern Phys."},{"key":"B20","author":"Hansen","year":"2010","journal-title":"MEG: An Introduction to Methods."},{"key":"B21","doi-asserted-by":"publisher","first-page":"244","DOI":"10.1016\/j.neuroimage.2019.03.022","article-title":"On-scalp MEG system utilizing an actively shielded array of optically-pumped magnetometers.","volume":"194","author":"Iivanainen","year":"2019","journal-title":"NeuroImage"},{"key":"B22","doi-asserted-by":"publisher","first-page":"417","DOI":"10.1016\/j.neuroimage.2017.06.030","article-title":"Autoreject: automated artifact rejection for MEG and EEG data.","volume":"159","author":"Jas","year":"2017","journal-title":"Neuroimage"},{"key":"B23","doi-asserted-by":"publisher","first-page":"172","DOI":"10.1097\/00004691-199603000-00008","article-title":"Cardiac artifacts in magnetoencephalogram.","volume":"13","author":"Jousm\u00e4ki","year":"1996","journal-title":"J. Clin. Neurophysiol."},{"key":"B24","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1515\/9783110863529-004","article-title":"Construction and performance of the Otaniemi magnetically shielded room","author":"Kelha","year":"1981","journal-title":"Biomagnetism: Proceedings of the Third International Workshop on Biomagnetism"},{"key":"B25","doi-asserted-by":"publisher","first-page":"E10465","DOI":"10.1073\/pnas.1705414114","article-title":"Sparsity enables estimation of both subcortical and cortical activity from MEG and EEG.","volume":"114","author":"Krishnaswamy","year":"2017","journal-title":"Proc. Natl. Acad. Sci. U.S.A."},{"key":"B26","doi-asserted-by":"publisher","first-page":"1002","DOI":"10.1109\/TBME.2017.2734641","article-title":"Reducing sensor noise in MEG and EEG recordings using oversampled temporal projection.","volume":"65","author":"Larson","year":"2018","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"B27","doi-asserted-by":"publisher","first-page":"4942","DOI":"10.1073\/pnas.1913135117","article-title":"Noninvasive muscle activity imaging using magnetography.","volume":"117","author":"Llin\u00e1s","year":"2020","journal-title":"Proc. Natl. Acad. Sci. U.S.A."},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.3389\/fncir.2014.00043","article-title":"Frequency-pattern functional tomography of magnetoencephalography data allows new approach to the study of human brain organization.","volume":"8","author":"Llin\u00e1s","year":"2014","journal-title":"Front. Neural Circ."},{"key":"B29","author":"Llin\u00e1s","year":"2016","journal-title":"Precise Frequency-Pattern Analysis to Decompose Complex Systems into Functionally Invariant Entities: U.S. Patent."},{"key":"B30","doi-asserted-by":"publisher","DOI":"10.3389\/fnins.2015.00373","article-title":"Reconstruction of human brain spontaneous activity based on frequency-pattern analysis of magnetoencephalography data.","volume":"9","author":"Llin\u00e1s","year":"","journal-title":"Front. Neurosci."},{"key":"B31","article-title":"Structure and function of the sources of thalami-cortical dysrhythmia in human, revealed by magnetic encephalography","author":"Llin\u00e1s","year":"","journal-title":"Proceedings of the 2015 Program No.542.13 Neuroscience Meeting Planner"},{"key":"B32","first-page":"33","article-title":"A magnetically shielded room","author":"Mager","year":"1981","journal-title":"Biomagnetism: Proceedings of the Third International Workshop on Biomagnetism"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.1038\/ncomms14896","article-title":"Human seizures couple across spatial scales through travelling wave dynamics.","volume":"8","author":"Martinet","year":"2017","journal-title":"Nat. Commun."},{"key":"B34","article-title":"Advanced electronics for the CTF MEG system.","volume":"2004","author":"McCubbin","year":"2004","journal-title":"Neurol. Clin. Neurophysiol."},{"key":"B35","doi-asserted-by":"publisher","first-page":"135","DOI":"10.1016\/j.neuroimage.2017.10.021","article-title":"Automatic and robust noise suppression in EEG and MEG: the SOUND algorithm.","volume":"166","author":"Mutanen","year":"2018","journal-title":"Neuroimage"},{"key":"B36","doi-asserted-by":"publisher","first-page":"1182","DOI":"10.1016\/j.neuroimage.2015.04.028","article-title":"OMEGA: the open MEG Archive.","volume":"124","author":"Niso","year":"2015","journal-title":"Neuroimage"},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.1063\/1.4962020","article-title":"BabyMEG: a whole-head pediatric magnetoencephalography system for human brain development research.","volume":"87","author":"Okada","year":"2016","journal-title":"Rev. Sci. Instruments"},{"key":"B38","doi-asserted-by":"publisher","first-page":"78","DOI":"10.1016\/j.neuroimage.2011.02.002","article-title":"Spectral signal space projection algorithm for frequency domain MEG and EEG denoising, whitening, and source imaging.","volume":"56","author":"Ram\u00edrez","year":"2011","journal-title":"Neuroimage"},{"key":"B39","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1007\/s10548-005-7899-7","article-title":"Cardio-respiratory contributions to the magnetoencephalogram.","volume":"18","author":"Rodin","year":"2005","journal-title":"Brain Topogr."},{"key":"B40","doi-asserted-by":"publisher","first-page":"287","DOI":"10.1007\/bf00681735","article-title":"SQUID magnetometers for low-frequency applications.","volume":"76","author":"Ryhanen","year":"1989","journal-title":"J. Low Temperature Phys."},{"key":"B41","doi-asserted-by":"publisher","first-page":"716","DOI":"10.1134\/S1054661820040227","article-title":"FTViewer application for analysis and visualization of functional tomograms of complex systems.","volume":"30","author":"Rykunov","year":"2020","journal-title":"Pattern Recogn. Image Anal."},{"key":"B42","doi-asserted-by":"publisher","first-page":"127","DOI":"10.17537\/2016.11.127","article-title":"Software for the partial spectroscopy of human brain.","volume":"11","author":"Rykunov","year":"2016","journal-title":"Math. Biol. Bioinform."},{"key":"B43","first-page":"233","article-title":"Denoising source separation.","volume":"6","author":"Sarela","year":"2005","journal-title":"J. Mach. Learn. Res."},{"key":"B44","doi-asserted-by":"publisher","first-page":"11","DOI":"10.1088\/0031-9155\/32\/1\/004","article-title":"Basic mathematical and electromagnetic concepts of the biomagnetic inverse problem.","volume":"32","author":"Sarvas","year":"1987","journal-title":"Phys. Med. Biol."},{"key":"B45","doi-asserted-by":"publisher","first-page":"1755","DOI":"10.1109\/TBME.2006.878119","article-title":"A novel adaptive beamformer for MEG source reconstruction effective when large background brain activities exist.","volume":"53","author":"Sekihara","year":"2006","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"B46","doi-asserted-by":"publisher","DOI":"10.7554\/eLife.48065","article-title":"Electrocorticographic dissociation of alpha and beta rhythmic activity in the human sensorimotor system.","volume":"8","author":"Stolk","year":"2019","journal-title":"eLife"},{"key":"B47","doi-asserted-by":"publisher","first-page":"783","DOI":"10.1007\/s10548-016-0513-3","article-title":"Removing cardiac artefacts in magnetoencephalography with resampled moving average subtraction.","volume":"29","author":"Sun","year":"2016","journal-title":"Brain Topogr."},{"key":"B48","doi-asserted-by":"publisher","DOI":"10.1088\/2057-1976\/aad627","article-title":"Noise cancellation for a whole-head magnetometer-based MEG system in hospital environment.","volume":"4","author":"Sun","year":"2018","journal-title":"Biomed. Phys. Eng. Express"},{"key":"B49","doi-asserted-by":"publisher","first-page":"31","DOI":"10.1016\/j.jneumeth.2013.04.002","article-title":"Cleaning MEG artifacts using external cues.","volume":"217","author":"Tal","year":"2013","journal-title":"J. Neurosci. Methods"},{"key":"B50","doi-asserted-by":"publisher","first-page":"269","DOI":"10.1023\/B:BRAT.0000032864.93890.f9","article-title":"Suppression of interference and artifacts by the signal space separation method.","volume":"16","author":"Taulu","year":"2004","journal-title":"Brain Topogr."},{"key":"B51","doi-asserted-by":"publisher","first-page":"1759","DOI":"10.1088\/0031-9155\/51\/7\/008","article-title":"Spatiotemporal signal space separation method for rejecting nearby interference in MEG measurements.","volume":"51","author":"Taulu","year":"2006","journal-title":"Phys. Med. Biol."},{"key":"B52","doi-asserted-by":"publisher","first-page":"2118","DOI":"10.1109\/77.403001","article-title":"Noise cancellation by a whole-cortex SQUID MEG system.","volume":"5","author":"Vrba","year":"1995","journal-title":"IEEE Trans. Appl. Superconduct."},{"key":"B53","doi-asserted-by":"publisher","first-page":"603","DOI":"10.1016\/j.ics.2007.01.061","article-title":"Comparison of external noise cancellation in MEG.","volume":"1300","author":"Vrba","year":"2007","journal-title":"Int. Congr. Ser."},{"key":"B54","doi-asserted-by":"publisher","first-page":"1269.e4","DOI":"10.1016\/j.neuron.2018.05.019","article-title":"Theta and alpha oscillations are traveling waves in the human neocortex.","volume":"98","author":"Zhang","year":"2018","journal-title":"Neuron"}],"container-title":["Frontiers in Neural Circuits"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fncir.2022.834434\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,8,26]],"date-time":"2022-08-26T04:53:10Z","timestamp":1661489590000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fncir.2022.834434\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,8,26]]},"references-count":54,"alternative-id":["10.3389\/fncir.2022.834434"],"URL":"https:\/\/doi.org\/10.3389\/fncir.2022.834434","relation":{},"ISSN":["1662-5110"],"issn-type":[{"value":"1662-5110","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,8,26]]},"article-number":"834434"}}