Apparatus for measuring brain local activity

For measuring a brain local activity, a predetermined frequency bandwidth wider than a frequency bandwidth of alpha waves of scalp potentials is divided into a predetermined number of frequency banks each having a fixed frequency width, data of each divided frequency bank is divided into segments of a predetermined duration on a time axis, a Z-score of the subject is determined from a first mean value of normalized power variances determined for the segments and a second mean value of normalized power variances predetermined in the same manner as the first mean value for a predetermined normal person group and a standard deviation of the normalized power variances in the group, and a mean value of the Z-scores determined over all of the frequency banks is mapped on a brain surface for each sensor, whereby a template of a specified brain disorder and likelihood of a subject to a specified brain disorder are calculated.