Tracking the Time-Varying Cortical Connectivity Patterns by Adaptive Multivariate Estimators
- 15 February 2008
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Biomedical Engineering
- Vol. 55 (3) , 902-913
- https://doi.org/10.1109/tbme.2007.905419
Abstract
The directed transfer function (DTF) and the partial directed coherence (PDC) are frequency-domain estimators that are able to describe interactions between cortical areas in terms of the concept of Granger causality. However, the classical estimation of these methods is based on the multivariate autoregressive modelling (MVAR) of time series, which requires the stationarity of the signals. In this way, transient pathways of information transfer remains hidden. The objective of this study is to test a time-varying multivariate method for the estimation of rapidly changing connectivity relationships between cortical areas of the human brain, based on DTF/PDC and on the use of adaptive MVAR modelling (AMVAR) and to apply it to a set of real high resolution EEG data. This approach will allow the observation of rapidly changing influences between the cortical areas during the execution of a task. The simulation results indicated that time-varying DTF and PDC are able to estimate correctly the imposed connectivity patterns under reasonable operative conditions of signal-to-noise ratio (SNR) ad number of trials. An SNR of Ave and a number of trials of at least 20 provide a good accuracy in the estimation. After testing the method by the simulation study, we provide an application to the cortical estimations obtained from high resolution EEG data recorded from a group of healthy subject during a combined foot-lips movement and present the time-varying connectivity patterns resulting from the application of both DTF and PDC. Two different cortical networks were detected with the proposed methods, one constant across the task and the other evolving during the preparation of the joint movement.Keywords
This publication has 26 references indexed in Scilit:
- Estimation of the effective and functional human cortical connectivity with structural equation modeling and directed transfer function applied to high-resolution EEGMagnetic Resonance Imaging, 2004
- Determination of EEG Activity Propagation: Pair-Wise Versus Multichannel EstimateIEEE Transactions on Biomedical Engineering, 2004
- Human cortical responses during one-bit short-term memory. A high-resolution EEG study on delayed choice reaction time tasksClinical Neurophysiology, 2003
- The use of time-variant EEG Granger causality for inspecting directed interdependencies of neural assembliesJournal of Neuroscience Methods, 2003
- Synchronization likelihood: an unbiased measure of generalized synchronization in multivariate data setsPhysica D: Nonlinear Phenomena, 2002
- Partial directed coherence: a new concept in neural structure determinationBiological Cybernetics, 2001
- Instantaneous multivariate EEG coherence analysis by means of adaptive high-dimensional autoregressive modelsJournal of Neuroscience Methods, 2001
- Short-window spectral analysis of cortical event-related potentials by adaptive multivariate autoregressive modeling: data preprocessing, model validation, and variability assessmentBiological Cybernetics, 2000
- A new method of the description of the information flow in the brain structuresBiological Cybernetics, 1991
- Investigating Causal Relations by Econometric Models and Cross-spectral MethodsEconometrica, 1969