Differential classification of states of consciousness using envelope- and phase-based functional connectivity
Neuroimage May 14, 2021 C. Duclos, C. Maschke, Yacine Mahdid et al.
Amplitude-based (AEC) and phase-based (wPLI) measures of functional connectivity yield different patterns of brain network activity across states of consciousness. In nine healthy participants undergoing propofol and isoflurane anesthesia, AEC showed strongest connectivity during deep unconsciousness, while wPLI showed strongest connectivity during full consciousness. AEC outperformed wPLI in classifying anesthetic-induced unconsciousness from baseline (83.7% accuracy), distinguishing deep from light unconsciousness (66.3% vs. 56.2%), and separating responsiveness from unresponsiveness (76.0% vs. 63.6%). Combining both measures did not improve accuracy over AEC alone. The authors conclude that envelope-based measures better detect alterations in brain connectivity across levels of anesthetic-induced unconsciousness.