A system and method are presented for use in monitoring brain activity of a subject. The system comprises a control unit which comprises: a data input utility for receiving measured data comprising data corresponding to signals measured during a certain time period and being indicative of a subjects brain activity originated from locations in the subjects brain during said certain time period, and a processor utility which is configured and operable for processing the measured data and generating data indicative thereof in the form of a multi-parameter function presenting a relation between frequency and time data of the measured signals and for analyzing said relation and identifying a subject-related signature corresponding to the subjects brain neural activity.