EEG Measures Indicating Anaesthesia Induced Changes of Cortical Information Processing

Abstract

Consciousness is related to the brains ability to process information.This is inline with EEG studies observing decreased signal``complexity{''} under anaesthesia induced unconsciousness. In thepresent investigation, 64-channel electroencephalogram (EEG) of 15volunteers was analyzed during consciousness, propofol induced sedationand unconsciousness. Univariate EEG parameters (spectral power, Higuchifractal dimension, permutation entropy) and cortico-cortical informationexchange in EEG based on symbolic transfer entropy (STE) were analysedto indicate effects of anaesthetics on the systemic informationprocessing of the brain. The STE revealed affected interaction betweenfrontal and parietal brain regions during unconsciousness.