1. A method of monitoring consciousness of a sentient subject and automatically detecting whether the subject is in a transition from a conscious state to a less conscious state or vice versa, by reducing effects of frequency based changes in neurological data from the subject, said method comprising: (i) obtaining an EEG signal from the subject; (ii) performing a frequency based analysis of the EEG signal to obtain a frequency-based signal; (iii) performing a phase based analysis of the EEG signal to obtain a phase-based signal ; (iv) detecting by comparing the frequency based signal and the phase based signal whether the subject is in transition from said conscious state to said less conscious state or vice versa; and (v) providing a warning signal when said subject is in said transition to said conscious state.