Abstract: A diagnostic method is disclosed wherein brain evoked potential (EP) data from a plurality of electrode sites on the patient's head is gathered and compared with a comparable EP for normal patients by forming (1) the cross-correlation between the patient's EP and the normal EP, (2) the maximum cross-correlation for any time shift in a selected period or C.sub.max, and (3) the time shift T.sub.max at which the maximum correlation occurs. Selected ones of these values for particular evoked potentials are used to compute diagnostic feature values, and a plurality of diagnostic feature values are used to achieve a diagnosis of brain pathology.

Abstract: A method is disclosed for utilizing brain evoked potentials for characterizing brain pathology. A brain electrical activity map is prepared from a patient's evoked potential data, and the centers of gravity of peaks of the evoked potential are calculated for a sequence of frames of the map, and plotted in a single frame to provide a spatial trajectory which may then be compared to a patient norm in order to detect and characterize brain pathology.

Abstract: Pathological changes in brain electrical activity over time caused by for example growth of a lesion are detected by producing a brain electrical activity map such as a statistical probability map, and then selecting a template or mask surrounding a suspect area, summating values of the map within the template area to form an aggregate statistical feature, and then plotting the feature over a period of time, e.g. several weeks, to form a trend plot characteristic of brain electrical activity changes.

Abstract: Apparatus for generating a topographic display of information on brain electrical activity based on responses of electrical-activity transducers placed on the skull.

Abstract: Topographic displays of brain electrical activity are produced from matrices of data derived from evoked potential (EP) and steady-state responses of skull transducers. In different aspects, EP responses are displayed at a variable frame rate, the rate of data sampling is sufficient to capture rapid transient events, difference matrices are derived as the difference between matrices corresponding to two different brain conditions, the baseline of the EP responses is zeroed based on the average prestimulus response, and the steady-state response is analyzed by Fourier transforms.

Abstract: Apparatus for generating a topographic display of information on brain electrical activity based on responses of electrical-activity transducers placed on the skull.