Figure 3.

The PCI differentiates between conscious and unconscious subjects. Each circle represents the PCI value computed from the cortical responses to TMS of one stimulation site. PCI values are computed from TMS-evoked potentials recorded in healthy subjects and conscious brain-injured patients during different conditions. Individuals are grouped by condition, and within each condition are sorted by increasing age. During non-rapid eye movement (NREM) sleep and anesthesia with midazolam, xenon, and propofol, subjects were behaviorally unresponsive and did not provide any report upon awakening. During dreaming and ketamine anesthesia, subjects were behaviorally unresponsive but provided delayed subjective reports upon awakening. During wakefulness, both healthy subjects and conscious brain-injured patients (with locked-in syndrome-LIS, subcortical and cortical stroke, patients who emerged from the MCS-EMCS) could immediately report their subjective experience. The dashed horizontal line represents the empirical cutoff PCI* obtained by applying ROC curve analysis using the presence/absence of report as the gold standard (modified from Casarotto et al. 2016).