Performance of an MEG adaptive-beamformer technique in the presence of correlated neural activities: Correlation-coefficient estimation and time-course retrieval

Kensuke Sekihara, Srikantan S. Nagarajan, David Poeppel, Alec Marantz

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The influence of temporarily correlated source activities on neuromagnetic reconstruction by adaptive beamformer techniques is investigated. It is known that the spatial filter weight of an adaptive beamformer cannot perfectly block correlated signals. This causes two major influences on the reconstruction results: time course distortions and reductions in reconstructed signal intensities. The reduction in signal intensity for sources with a medium degree of correlation is found to be insignificant. The time course distortion for such sources, however, may not be negligible. Our analysis shows that the magnitude correlation coefficient between two correlated sources can be accurately estimated by using the beamformer outputs. A method of retrieving the original time courses using estimated correlation coefficients is developed. Our numerical experiments demonstrate that reasonably accurate time courses can be retrieved from considerably distorted time courses even when the signalto-noise ratio is low.

Original languageEnglish (US)
Title of host publication2002 IEEE International Symposium on Biomedical Imaging, ISBI 2002 - Proceedings
PublisherIEEE Computer Society
Pages1019-1022
Number of pages4
ISBN (Electronic)078037584X
DOIs
StatePublished - 2002
EventIEEE International Symposium on Biomedical Imaging, ISBI 2002 - Washington, United States
Duration: Jul 7 2002Jul 10 2002

Publication series

NameProceedings - International Symposium on Biomedical Imaging
Volume2002-January
ISSN (Print)1945-7928
ISSN (Electronic)1945-8452

Other

OtherIEEE International Symposium on Biomedical Imaging, ISBI 2002
CountryUnited States
CityWashington
Period7/7/027/10/02

ASJC Scopus subject areas

  • Biomedical Engineering
  • Radiology Nuclear Medicine and imaging

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