Age-related changes of spontaneous EEG described by equivalent dipoles

One of the most commonly used methods for quantification of an EEG is Fast Fourier Transformation (FFT), which suffers from some serious disadvantages, for example: FFT-power data are highly dependent on the choice of reference and thus the topographical distribution of FFT-power data varies according to the used reference. Novel methods which partly resolve this problem have been developed. These methods provide unambiguous data in the frequency domain with regard to reference. In comparison to conventional FFT-power data this approach allows to a higher degree to draw topographical valid conclusions regarding brain function. The aim of the present study on brain electrical activity, using the method of FFT approximation, was to investigate age-related alterations of brain function in carefully screened healthy subjects. The major finding was that, except for a more superficially located beta-activity of higher strength with increasing, age no age-related changes in electrical brain activity were observed.