| abstract |
In a method and an apparatus for measuring the degree of neuronalnimpairment in brain cortex, scalp potentials or magnetic fieldsnof a subject are measured by mounting a plurality of sensors (2) on thenhead of the subject, the measured scalp potentials or magnetic fieldsnare converted into numerical data to obtain a dipolarity at each sampling,nmean values of squared errors, within a fixed time interval,nbetween a scalp potential or a magnetic field by an equivalent dipolenat a dipolarity peak emergence time and the measured scalp potentialsnor magnetic fields, or variances of the squared errors from thenmean values are obtained for the sensors, and a contour concerning andistribution of the mean values or the variances on a scalp or a brainnsurface corresponding thereto is mapped as an output. Alternatively,nthe squares of potentials sensed by the sensors are averaged for severalnseconds, and variances of these mean values are obtained fornnumerous reference persons. |