Fig. 1.

Results from propofol infusion in a single representative subject. (A) Time course of propofol infusion and behavioral response. The green traces indicate the latency of correct responses to auditory stimuli. Cessation of response indicates anesthetic-induced loss of consciousness. The red trace describes the estimated propofol blood concentration. (B) Whole-study spectrogram from a frontal electrode. Loss of consciousness coincides with the emergence of broadband β-activity, which strengthens and slows into the α-range as the infusion increases. (C) Coherent EEG activity. At the deepest levels of general anesthesia the α-band exhibits high global coherence (2); being frontal, it is distinct from the classic occipital α in anatomical location.