A method of displaying a brain activity, the method including the steps of: (i) obtaining a signal electroencephalogram (EEG) of the scalp of a subject and converting the EEG signal into a signal digitized EEG data (Ii) segmenting said EEG signal into a plurality of segments each including a predetermined number of sequential samples of said EEG signal and performing artifact rejection segments number (Iii) representing said segments of EEG as a signal representation of autoregressive moving average (ARMA) fixed order, time-invariant, with an autoregressive order (AR) between 8 and 13 and an order moving average (MA) between 5 and 11 (Iv) generating coefficient data AR and MA coefficient data for said segments of said EEG signal to said representation of the ARMA signal fixed order (V) generate signal representations for said segments of the EEG signal replacing the coefficient data AR generated and coefficient data MA to said segments of the EEG signal in said ARMA fixed order representation and provide input white noise normalized as control input to said EEG signal representation (Vi) generating a gain value ARMA (YY (t) as the mean square root of the amplitude values for said signal representations to said segments of EEG (vi) generating product data representative of the input bark dividing the mean square root of the amplitude of the EEG signal to said segments (y (t)) by the gain value ARMA (Y (t)) for said signal representations of said segments of EEG and (viii) displaying such product data on display means.Un método para mostrar la actividad de un cerebro, incluyendo el método las etapas de: (i) obtener una señal de electroencefalograma (EEG) del cuero cabelludo de un sujeto y convertir la señal de EEG en una señal de datos de EEG digitalizada (ii) segmentar dicha señal de EEG en una pluralidad de segmentos que incluyen cada uno un número predeterminado de muestras secuenciales de dicha señal de EEG y realizar el rechazo de artefacto en los segmentos (ii