A process for analysing an electroencephalogram (EEG) signal representativeof activity of a brain of a subject, including: (i) generating coefficient datafor a signal representation of a portion of the EEG signal； (ii) generating, basedon the coefficient data, cortical state data representing the brain'sreceptivity to subcortical input and input from other areas of cortex； (iii)generating cortical input data representing a level of subcortical input tothe brain at a time corresponding to the portion of the EEG signal； (iv) generating,based on the cortical state data and the cortical input data, display data representingthe functional state of the brain of the subject； and (v) displaying the displaydata on display means.
