Cross-correlation Analysis of the Correspondence between Magnetoencephalographic and Near-infrared Cortical Signals

T. H. Sander; A. Liebert; M. Burghoff; H. Wabnitz; R. Macdonald; L. Trahms

doi:10.1055/s-0038-1625400

Methods of Information in Medicine, Table of Contents

Methods Inf Med 2007; 46(02): 164-168
DOI: 10.1055/s-0038-1625400

Original Article

Schattauer GmbH

Cross-correlation Analysis of the Correspondence between Magnetoencephalographic and Near-infrared Cortical Signals

T. H. Sander

¹Physikalisch-Technische Bundesanstalt, Division of Medical Physics, Berlin, Germany

,

A. Liebert

²Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland

,

M. Burghoff

¹Physikalisch-Technische Bundesanstalt, Division of Medical Physics, Berlin, Germany

,

H. Wabnitz

¹Physikalisch-Technische Bundesanstalt, Division of Medical Physics, Berlin, Germany

,

R. Macdonald

¹Physikalisch-Technische Bundesanstalt, Division of Medical Physics, Berlin, Germany

,

L. Trahms

¹Physikalisch-Technische Bundesanstalt, Division of Medical Physics, Berlin, Germany

› Author Affiliations

Abstract

Summary

Objectives : The study of neurovascular coupling greatly benefits from combined measurements of neuronal and vascular signals. Two-step signal processing is developed to extract parameters describing the coupling.

Methods : Using a magnetometer in an extremely well shielded room a broadband magnetoencephalogram was simultaneously measured with time-resolved nearinfrared spectroscopy during a motor activity paradigm. The raw MEG and NIRS data were denoised separately using independent component analysis.

Results : After averaging the resulting signals showed motor activity-related changes. The temporal correspondence between MEG and NIRS was assessed plotting a combined trajectory and calculating a crosscorrelation. Compared to the MEG signal, at movement onset the NIRS signal showed an onsetdelay in the range of seconds.

Conclusions : Multi-variate signal pre-processing followed by temporal delay estimates demonstrated the extraction of neurovascular coupling parameters.

Keywords

Direct current magnetoencephalography - near-infrared spectroscopy - independent component analysis - cross-correlation - neurovascular coupling

Full Text

References

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