Fig. 3.
Effects of propofol-induced loss of consciousness (PI-LOC) on functional magnetic resonance imaging functional connectivity (FC). The FC analysis of resting-state brain networks during PI-LOC showed decreased FC in the posterior (A) and anterior (B) default mode network, whereas the auditory (C) and visual (D) primary sensory networks showed increased FC. On the left, the average (avg) network for 12 subjects is displayed on the glass brain template of statistical parametric mapping (SPM) 8 (Wellcome Trust Centre for Neuroimaging, University of London, London, United Kingdom; full-factorial ANOVA, F-contrast over all subjects and conditions at the family-wise error-corrected cluster threshold P < 0.05 and the uncorrected voxel threshold P < 0.001) for both conditions (at wakefulness [AW]; PI-LOC). On the right, significant intrinsic FC changes between AW and PI-LOC are displayed on the average T1 brain template of SPM 8 (full-factorial ANOVA: T-contrast of condition-specific effects at the same thresholds, with the exception of the primary auditory cortex. Here, only the right auditory cortex survived a family-wise error-corrected cluster threshold at the predefined voxel threshold of P < 0.001; after lowering the (whole-brain) voxel threshold to P < 0.005, we also found significant family-wise error-corrected changes in FC in the left auditory cortex). The red to yellow scales indicate increased FC; the dark to light blue scales indicate decreased FC.