1. An electroencephalographic (EEG) system including: brain wave signal means to detect and amplify brain waves from the head of a patient, comprising a plurality of electrodes removably attached to a plurality of sectors of the patient's head to detect signals representing said brain waves, amplifiers connected to the electrodes, and analog/digital conversion means connected to the amplifiers to produce sets of digital data representing said brain waves from a selected plurality of sectors of the patient's head; memory means to store selected reference normative data, said normative data being selected from the group of data for some prior state of the patient and data of population norms; data analysis means connected to said brain wave signal means and said memory means to analyze the said brain wave signals on a statistical basis as compared to said reference normative data to produce a plurality of analysis samples; and display means connected to said data analyses means to visually display said analysis, characterized in that the display means comprises means to display said plurality of analysis samples as a plurality of rectangular stripes and means to modulate said stripes so that each of the stripes is modulated to represent the result of the said statistical analysis, the modulation being from the group of gray-scale code and color-code whose modulation is coded to the significance of the said statistical analysis; and means to form said stripes into a pile of said stripes, said pile having opposite ends with an oldest-in-time stripe at one end, and a youngest-in-time stripe at the opposite end, said pile forming a moving window display in which the oldest-in-time stripe at one end of the pile is removed and replaced by a new youngest-in-time stripe at the opposite end of the pile.