Abstract: An apparatus and method for automatically determining an individual's level of brain function is provided. EEG or MEG signals are collected amplified and digitized. The signals are then passed to a computer comprising a CPU, ROM and RAM, an input interface for collecting and filtering the scalp potential signals and an output interface for displaying the resulting information on a display device such as a printer or CRT. The computer determines the position of these signals in reference to the interpolated 3-D geometry of the subject's head. The dipolarity of a particular point is iteratively and empirically derived by comparing the values of these measured signals to a test signal and the error between the two is minimized. The procedure is repeated for the complete series of electrodes placed on the skull. The mean dipolarity of a subject is then determined for a given time frame.