Covariation of spectral and nonlinear EEG measures with alpha biofeedback.
This study investigated how different spectral and nonlinear EEG measures covaried with alpha power during auditory alpha biofeedback training, performed by 13 healthy subjects. We found a significant positive correlation of alpha power with the largest Lyapunov-exponent, pointing to an increased dynamical instability of the EEG accompanying alpha enhancement. Alpha power amplification, moreover, was significantly correlated with a decrease of spectral entropy within the alpha range. This outcome reflects a sharpening of the alpha peak during biofeedback training. The fact that the sharpening effect clearly preceded the increase of alpha amplitude could be exploited in future biofeedback settings.
Fell
Jürgen
J
Department of Epileptology, University of Bonn, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany. juergen.fell@ukb.uni-bonn.de
Elfadil
Hakim
H
Klaver
Peter
P
Röschke
Joachim
J
Elger
Christian E
CE
Fernández
Guillén
G
D000328:Adult; D000513:Alpha Rhythm; D001676:Biofeedback, Psychology / Q000502:physiology*; D001921:Brain / Q000502:physiology; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results