Evidence map›Paper›PMID 41002325›Full record

ArticleBiosensors2025

Head-Specific Spatial Spectra of Electroencephalography Explained: A Sphara and BEM Investigation.

Uwe Graichen, Sascha Klee, Patrique Fiedler, Lydia Hofmann, Jens Haueisen

Abstract read
In one paragraph

Article in Biosensors, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Uwe GraichenDivision Biostatistics and Data Science, Karl Landsteiner University of Health Sciences, Dr.-Karl-Dorrek-Str. 30, 3500 Krems an der Donau, Austria.ORCID 0000-0003-2144-4682
Sascha KleeDivision Biostatistics and Data Science, Karl Landsteiner University of Health Sciences, Dr.-Karl-Dorrek-Str. 30, 3500 Krems an der Donau, Austria.ORCID 0000-0002-0321-1255
Patrique FiedlerInstitute of Biomedical Engineering and Informatics (BMTI), Faculty of Computer Science and Automation, Technische Universität Ilmenau, Gustav-Kirchhoff-Str. 2, 98693 Ilmenau, Germany.ORCID 0000-0001-9196-0717
Lydia HofmannInstitute of Biomedical Engineering and Informatics (BMTI), Faculty of Computer Science and Automation, Technische Universität Ilmenau, Gustav-Kirchhoff-Str. 2, 98693 Ilmenau, Germany.ORCID 0009-0007-4503-6401
Jens HaueisenInstitute of Biomedical Engineering and Informatics (BMTI), Faculty of Computer Science and Automation, Technische Universität Ilmenau, Gustav-Kirchhoff-Str. 2, 98693 Ilmenau, Germany.ORCID 0000-0003-3871-2890

Funding

European Union Marie Skłodowska-Curie Innovative Training Network 101007521 (project EMBRACE)German Federal Ministry of Education and Research 01GQ2304AGerman Research Foundation GR 5251/1-1
6 · The paper itself

Abstract

Electroencephalography (EEG) is a non-invasive biosensing platform with a spatial-frequency content that is of significant relevance for a multitude of aspects in the neurosciences, ranging from optimal spatial sampling of the EEG to the design of spatial filters and source reconstruction. In the past, simplified spherical head models had to be used for this analysis. We propose a method for spatial frequency analysis in EEG for realistically shaped volume conductors, and we exemplify our method with a five-compartment Boundary Element Method (BEM) model of the head. We employ the recently developed technique for spatial harmonic analysis (Sphara), which allows for spatial Fourier analysis on arbitrarily shaped surfaces in space. We first validate and compare Sphara with the established method for spatial Fourier analysis on spherical surfaces, discrete spherical harmonics, using a spherical volume conductor. We provide uncertainty limits for Sphara. We derive relationships between the signal-to-noise ratio (SNR) and the required spatial sampling of the EEG. Our results demonstrate that conventional 10-20 sampling might misestimate EEG power by up to 50%, and even 64 electrodes might misestimate EEG power by up to 15%. Our results also provide insights into the targeting problem of transcranial electric stimulation.

Indexed as

Biosensing TechniquesElectroencephalographyHeadFourier AnalysisHumansSignal-To-Noise RatioBoundary Element Method (BEM)Electroencephalography (EEG)forward modelingfrequency responsehead modelspatial filteringspatial harmonic analysis (Sphara)spatial Nyquist theoremtranscranial electrical stimulation (tES)volume conductor modeling

Identifiers

PMID41002325
PMCPMC12467547

What OpenQuestion holds

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LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.