Non-Canonical Microstate Becomes Salient in High Density EEG During Propofol-Induced Altered States of Consciousness
International Journal of Neural Systems January 23, 2020 Wen Shi, Yamin Li, Zhian Liu et al.
During propofol-induced sedation, a distinct EEG microstate pattern—a posterior central maximum labeled microstate F—emerges and becomes prominent. Its coverage, occurrence, and power significantly increase in moderate sedation, and the transition from rest to sedation is accompanied by a significant rise in mean energy across all frequency bands in this microstate. The findings suggest that microstate F is closely linked to propofol-altered consciousness and may derive from the canonical anterior-posterior microstate C. The work also advances methods for analyzing microstates in the frequency domain using multivariate empirical mode decomposition and Hilbert-Huang transform.