Cerebral State Monitor (CSM)
Cerebral State Monitor (CSM) can measure a person's level of alertness. When a hypnotic trance is induced, the client's level of alertness has been shown to decrease. The level of alertness is measured under anesthesia using Cerebral State Monitor (CSM) EEG parameters. This can be used to measure the measure of resting state with eyes open and under non-guided relaxation. However, one cannot draw accurate conclusions from CSM readings as to whether the induction of trance is not also caused by relaxation deepened by guidance. Although it has long been postulated that way, the trance during hypnosis is not a sleep state, despite the detectable decrease in the CSM index.