Consciousness re-emerges from propofol-induced general anesthesia through a multiscale reorganization of brain activity, not a single event. Anesthesia is an organized low-frequency regime with aperiodic slow waves, alpha/beta rhythms, global alpha synchronization, and phase-amplitude coupling. After anesthetic cessation, this regime dissolves as neural excitability and complexity increase. Conscious behavior returns with a rapid transformation in high-gamma activity, shifting from random bursts to structured, task-selective, event-locked responses. The findings chart an electrophysiological map of how conscious cognition is extinguished, reconfigured, and restored in the human brain.
A theoretical model coupling the default mode network (DMN) and working memory network (WMN) simulates neural dynamics during encoding, maintenance, and retrieval phases. AMPA channels produce synchronous oscillations that shift oscillation patterns in both networks. Different NMDA conductance between networks generates multiple neural activity modes, potentially switching network states across memory phases. The number of sequentially memorized stimuli relates to energy consumption determined by internal parameters, with the DMN contributing to more stable working memory. Different memory phases correspond to different functional connections between DMN and WMN, with coupling strengths differing in phase synchronization. Phase synchronization characteristics of contained energy match observed negative and positive correlations between networks from fMRI experiments.