Figure 1.

EEG-based definition criteria of VIGALL for vigilance classification according to Bente (1964) & Roth (1961). Note: Vigilance stages were sub-classified (column 2) according to Bente (1964) and Roth (1961). Continuous EEG-based vigilance stages from full alertness to drowsiness are determined by VIGALL according to defined decision criteria (column 1). The first column presents that vigilance stage A is corresponding to the presence of high alpha power. Low alpha power features vigilance stage B. VIGALL classifies substages based on EEG-power source estimates using sLORETA: A1 (occipital ROI power (α) > = parietal and frontal ROI power(α)), A2 (occipital ROI power (α) < parietal and frontal ROI power(α) and temporal and parietal ROI power(α) > = frontal ROI 1.5* power (α)), A3 (occipital ROI power (α) < parietal and frontal ROI power(α) and temporal and parietal ROI power(α) < frontal ROI 1.5* power (α)), B1 (power(α+δ+θ) in one ROI = < 7.5*10^-6 μA²/mm⁴ per data point), B2/3 (power(α+δ+θ) in one ROI > 7.5*10^-6 μA²/mm4 per data point. The right column depicts EEG curves of native two-seconds-segments.