RT Journal Article
SR Electronic
T1 EEG signal diversity reflects capability for behavioral responsiveness during propofol sedation
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 444281
DO 10.1101/444281
A1 Michał Bola
A1 Paweł Orłowski
A1 Martyna Płomecka
A1 Artur Marchewka
YR 2018
UL http://biorxiv.org/content/early/2018/10/16/444281.abstract
AB Background Transitions between wakefulness and anesthesia are accompanied by profound changes in brain functioning. A key challenge is to disentangle neuronal mechanisms specific to loss and recovery of consciousness, from more general effects that are not directly related to the capacity for conscious experience. Measures of neuronal diversity have been recently proposed to constitute a robust correlate of the global states of consciousness. In the present study we investigated whether EEG signal diversity is indeed related to behavioral responsiveness during propofol sedation, or rather to the general drug-related effects.Methods We reanalyzed data collected from 20 subjects sedated with propofol. Based on the responsiveness to auditory stimuli all subjects were subdivided into two subgroups - responsive (n = 13), who remains awake throughout the experiment, and drowsy (n = 7), who becomes unresponsive during moderate sedation. Resting state EEG recorded during wakefulness and sedation was characterized by the Mean Information Gain - an information-theory measure estimating signal diversity.Results In line with our hypothesis, the drowsy group exhibited a decrease in diversity during sedation but, unexpectedly, the responsive group exhibited a robust increase in diversity (ANOVA group x state interaction: F(3) = 7.81, p < 0.001; BF10 > 100).Conclusions We revealed that propofol sedation is initially related to an increase in EEG signal diversity, and that only upon loss of responsiveness EEG diversity decreases. The qualitatively different pattern of changes in the responsive and drowsy groups makes EEG diversity a robust indirect index of responsiveness and, presumably, consciousness.Author Contributions:Conceived the study: MB; Analyzed data: PO, MB; Contributed analysis methods: MP; Interpreted data: MB, AM; Wrote the paper: MB. Revised the paper: MB, AM.