Time domain measures of inter-channel EEG correlations: a comparison of linear, nonparametric and nonlinear measures.
Correlations between ten-channel EEGs obtained from thirteen healthy adult participants were investigated. Signals were obtained in two behavioral states: eyes open no task and eyes closed no task. Four time domain measures were compared: Pearson product moment correlation, Spearman rank order correlation, Kendall rank order correlation and mutual information. The psychophysiological utility of each measure was assessed by determining its ability to discriminate between conditions. The sensitivity to epoch length was assessed by repeating calculations with 1, 2, 3, …, 8 s epochs. The robustness to noise was assessed by performing calculations with noise corrupted versions of the original signals (SNRs of 0, 5 and 10 dB). Three results were obtained in these calculations. First, mutual information effectively discriminated between states with less data. Pearson, Spearman and Kendall failed to discriminate between states with a 1 s epoch, while a statistically significant separation was obtained with mutual information. Second, at all epoch durations tested, the measure of between-state discrimination was greater for mutual information. Third, discrimination based on mutual information was more robust to noise. The limitations of this study are discussed. Further comparisons should be made with frequency domain measures, with measures constructed with embedded data and with the maximal information coefficient.
Department of Physics, Mindanao State University-Iligan Institute of Technology, 9200 Iligan City, Philippines.
J D
JD
Bonita
Department of Physics, Mindanao State University-Iligan Institute of Technology, 9200 Iligan City, Philippines.
L C C
LC
Ambolode
Thomas Jefferson University College of Medicine, Philadelphia, PA USA.
B M
BM
Rosenberg
Aquinas, LLC, Berwyn, PA 19312 USA.
C J
CJ
Cellucci
Lannister-Finn, Bryn Mawr, PA 19010 USA.
T A A
TA
Watanabe
Department of Military and Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA.
P E
PE
Rapp
Physics Department, Bryn Mawr College, Bryn Mawr, PA 19010 USA.
A M
AM
Albano
EEG; Kendall rank order correlation; Mutual information; Pearson product moment correlation; Quantitative EEG; Spearman rank order correlation