Evidence map›Paper›PMID 29526744›Full record

ArticleNeuroImage2018

Applying dimension reduction to EEG data by Principal Component Analysis reduces the quality of its subsequent Independent Component decomposition.

Fiorenzo Artoni, Arnaud Delorme, Scott Makeig

Abstract read
In one paragraph

Article in NeuroImage, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 54 papers.

0numbers the graph read from it
0cells of the map it votes in
54citing 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

54 citing papers in PubMed.

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  4. Task-Related Aperiodic EEG (1/f) Activity in Autism.Autism research : official journal of the International Society for Autism Research · 2026
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  9. Sensory Entrained TMS (seTMS) enhances motor cortex plasticity.bioRxiv : the preprint server for biology · 2025
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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

3 authors.

Fiorenzo ArtoniThe Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy; Translational Neural Engineering Laboratory, Center for Neuroprosthetics and Institute of Bioengineering, EPFL - Campus Biotech, Geneve, Switzerland. Electronic address: fiorenzo.artoni@epfl.ch.
Arnaud DelormeSwartz Center for Computational Neuroscience, Institute for Neural Computation, University of California San Diego, La Jolla, CA, 92093-0559, USA; Univ. Grenoble Alpes, CNRS, LNPC UMR 5105, Grenoble, France.
Scott MakeigSwartz Center for Computational Neuroscience, Institute for Neural Computation, University of California San Diego, La Jolla, CA, 92093-0559, USA.

Funding

EEGLAB: Software for Analysis of Human Brain DynamicsR01NS047293 · NINDS · UNIVERSITY OF CALIFORNIA, SAN DIEGO · PI Arnaud Delorme, Scott Makeig · 2004 to 2026
$10.2M
The Open EEGLAB Portal ProjectR01EB023297 · NIBIB · UNIVERSITY OF CALIFORNIA, SAN DIEGO · PI DELORME, ARNAUD, MAJUMDAR, AMITAVA · 2017 to 2020
$2.3M
NIBIB NIH HHS R01 EB023297NINDS NIH HHS R01 NS047293
6 · The paper itself

Abstract

Independent Component Analysis (ICA) has proven to be an effective data driven method for analyzing EEG data, separating signals from temporally and functionally independent brain and non-brain source processes and thereby increasing their definition. Dimension reduction by Principal Component Analysis (PCA) has often been recommended before ICA decomposition of EEG data, both to minimize the amount of required data and computation time. Here we compared ICA decompositions of fourteen 72-channel single subject EEG data sets obtained (i) after applying preliminary dimension reduction by PCA, (ii) after applying no such dimension reduction, or else (iii) applying PCA only. Reducing the data rank by PCA (even to remove only 1% of data variance) adversely affected both the numbers of dipolar independent components (ICs) and their stability under repeated decomposition. For example, decomposing a principal subspace retaining 95% of original data variance reduced the mean number of recovered 'dipolar' ICs from 30 to 10 per data set and reduced median IC stability from 90% to 76%. PCA rank reduction also decreased the numbers of near-equivalent ICs across subjects. For instance, decomposing a principal subspace retaining 95% of data variance reduced the number of subjects represented in an IC cluster accounting for frontal midline theta activity from 11 to 5. PCA rank reduction also increased uncertainty in the equivalent dipole positions and spectra of the IC brain effective sources. These results suggest that when applying ICA decomposition to EEG data, PCA rank reduction should best be avoided.

Indexed as

Data Interpretation, StatisticalSignal Processing, Computer-AssistedAdultBrainBrain WavesElectroencephalographyFemaleHumansMalePattern Recognition, VisualPrincipal Component AnalysisYoung AdultDipolarityElectroencephalogram, EEGIndependent component analysis, ICAPrincipal component analysis, PCAReliabilitySource localization

Identifiers

PMID29526744
PMCPMC6650744

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Registered trials

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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.