Cross-correlation analysis of the correspondence between magnetoencephalographic and near-infrared cortical signals

Methods Inf Med. 2007;46(2):164-8.

Abstract

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 near-infrared 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 cross-correlation. Compared to the MEG signal, at movement onset the NIRS signal showed an onset delay in the range of seconds.

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

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Central Nervous System / physiology*
  • Humans
  • Magnetoencephalography*
  • Models, Theoretical
  • Neurons / physiology*
  • Signal Processing, Computer-Assisted*
  • Signal Transduction / physiology*
  • Spectroscopy, Near-Infrared*
  • Statistics as Topic
  • Time