Slow-wave activity saturation parameters reveal clear separation of graded and abrupt slow-wave emergence trajectories. (A–D) Probability distribution of concentration required to achieve slow-wave activity saturation (Ce_SWAS) and slow-wave activity power at saturation (P_SWAS) on induction and emergence. Clear bimodal distributions in Ce_SWAS and P_SWAS on emergence can be observed for the graded (red) and abrupt (blue) slow-wave trajectories. The data are presented for the N = 175 patients in study 4 that had successful slow-wave activity saturation fits on both induction and emergence. Ce_SWAS is in µg/ml for induction and minimum alveolar concentration (MAC) for emergence due to the different hypnotic anesthetic agents used.