Fig. 3.

Spectral and global coherence analysis of the sevoflurane-plus-ketamine study visit. a Ketamine reduced the power of alpha oscillations during sevoflurane general anesthesia. b Power in the canonical slow-delta and alpha frequency bands change with respect to the anesthetic states. c Frontal spectra and bootstrapped difference of median spectra confirm that the ketamine-induced alpha oscillation power decrease was significant. Ketamine was also associated with a decrease in delta oscillation power and an increase in beta oscillation power. d The median global coherograms demonstrate ketamine reduced the global coherence of theta and alpha oscillations. e Global coherence in the canonical theta and alpha frequency bands change with respect to the anesthetic states. f Global coherence spectra and bootstrapped difference of median global coherence confirm that ketamine significantly reduced theta and alpha global coherence to suggest this dynamic is not fundamental for general anesthesia. Shaded regions represent the 99% confidence bounds of the bootstrapped median global coherence spectra. Black lines represent frequency bands that met our threshold for statistical significance