The LDA beamformer: Optimal estimation of ERP source time series using linear discriminant analysis

Matthias S. Treder, Anne K. Porbadnigk, Forooz Shahbazi Avarvand, Klaus Muller, Benjamin Blankertz

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

We introduce a novel beamforming approach for estimating event-related potential (ERP) source time series based on regularized linear discriminant analysis (LDA). The optimization problems in LDA and linearly-constrained minimum-variance (LCMV) beamformers are formally equivalent. The approaches differ in that, in LCMV beamformers, the spatial patterns are derived from a source model, whereas in an LDA beamformer the spatial patterns are derived directly from the data (i.e., the ERP peak). Using a formal proof and MEG simulations, we show that the LDA beamformer is robust to correlated sources and offers a higher signal-to-noise ratio than the LCMV beamformer and PCA. As an application, we use EEG data from an oddball experiment to show how the LDA beamformer can be harnessed to detect single-trial ERP latencies and estimate connectivity between ERP sources. Concluding, the LDA beamformer optimally reconstructs ERP sources by maximizing the ERP signal-to-noise ratio. Hence, it is a highly suited tool for analyzing ERP source time series, particularly in EEG/MEG studies wherein a source model is not available.

Original languageEnglish
Pages (from-to)279-291
Number of pages13
JournalNeuroImage
Volume129
DOIs
Publication statusPublished - 2016 Apr 1

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ASJC Scopus subject areas

  • Cognitive Neuroscience
  • Neurology

Cite this

Treder, M. S., Porbadnigk, A. K., Shahbazi Avarvand, F., Muller, K., & Blankertz, B. (2016). The LDA beamformer: Optimal estimation of ERP source time series using linear discriminant analysis. NeuroImage, 129, 279-291. https://doi.org/10.1016/j.neuroimage.2016.01.019