Preferential Inhibition of Frontal-to-Parietal Feedback Connectivity Is a Neurophysiologic Correlate of General Anesthesia in Surgical Patients
Figure 4
Power spectra and correlations of the frontal and parietal regions for the original and surrogate EEG.
The original (A) and surrogate EEG data (B) have the same power spectral densities for the frontal (solid lines) and parietal (dotted lines) regions for three states (red: baseline, blue: induction, green: anesthetized). The distribution of linear correlation coefficients (the zeroth lag of the normalized covariance function) between frontal and parietal EEG channels has a positive mean value (Inset in (A)), whereas the distribution for surrogate data has a zero mean value (Inset in (B)). n = 18 patients.