Truncated RAP-MUSIC (TRAP-MUSIC) for MEG and EEG source localization

Niko Mäkelä*, Matti Stenroos, Jukka Sarvas, Risto J. Ilmoniemi

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

9 Citations (Scopus)
82 Downloads (Pure)

Abstract

Electrically active brain regions can be located applying MUltiple SIgnal Classification (MUSIC) on magneto- or electroencephalographic (MEG; EEG) data. We introduce a new MUSIC method, called truncated recursively-applied-and-projected MUSIC (TRAP-MUSIC). It corrects a hidden deficiency of the conventional RAP-MUSIC algorithm, which prevents estimation of the true number of brain-signal sources accurately. The correction is done by applying a sequential dimension reduction to the signal-subspace projection. We show that TRAP-MUSIC significantly improves the performance of MUSIC-type localization; in particular, it successfully and robustly locates active brain regions and estimates their number. We compare TRAP-MUSIC and RAP-MUSIC in simulations with varying key parameters, e.g., signal-to-noise ratio, correlation between source time-courses, and initial estimate for the dimension of the signal space. In addition, we validate TRAP-MUSIC with measured MEG data. We suggest that with the proposed TRAP-MUSIC method, MUSIC-type localization could become more reliable and suitable for various online and offline MEG and EEG applications.

Original languageEnglish
Pages (from-to)73-83
Number of pages11
JournalNeuroImage
Volume167
DOIs
Publication statusPublished - 15 Feb 2018
MoE publication typeA1 Journal article-refereed

Keywords

  • EEG
  • Electroencephalography
  • Inverse methods
  • Magnetoencephalography
  • MEG
  • Multiple sources
  • Source localization

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