Related Experiment Video
Updated: Jul 13, 2026

Statistical Modelling of Cortical Connectivity Using Non-invasive Electroencephalograms
Published on: November 1, 2019
The influence of static correlations on multivariate correlation analysis of the EEG
Christian Rummel1, Gerold Baier, Markus Müller
1Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, 62209 Cuernavaca, Mor., Mexico. crummel@web.de
Abstract:
The choice of the EEG reference strongly influences the results derived from different correlation measures. Such a dependence may easily mislead the interpretation of the correlation structure of the brain activity. We provide a systematic study of the influence of the choice of reference on linear multivariate EEG correlation patterns as determined by sensitive correlation measures derived from the equal-time correlation matrix. In addition, an effective algorithm to extract the effect of static correlations is developed. The eigenvalues of the correlation matrix and their spacing statistics are studied for artificial time series with known correlation structure and for an epileptic EEG in various montages. The correction method proposed in this paper works with varying quality for different choices of the EEG reference. Furthermore, the optimal choice of the reference depends also on the correlation structure of the underlying system.
Related Concept Videos
Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
Correlations
Correlation
Two variables, for example, a and b, are said to be positively correlated if both variables move in the same direction. In other words, a positive correlation exists between two variables, a and b, if:
Correlation of Experimental Data
For example, a spherical particle moving through a viscous fluid experiences drag. Dimensional analysis shows that the drag force depends on the particle's diameter, velocity, and...
Correlation and Regression
Coefficient of Correlation
If you suspect a linear relationship between x and y, then r can measure how strong the linear relationship is.
What the VALUE of r tells us:
The value of r is always between –1 and +1: –1 ≤ r ≤ 1.
The size of the correlation r indicates the strength of the linear...

