Dipole localization at P300 and normal aging

At present, our understanding of how normal aging affects in vivo brain fun ction is rudimentary. Therefore, the aim of the present study was to invest igate age effects on auditory P300 topography. A recently developed dipole source model for P300 distinguishes overlapping P300 subcomponents and enha nces reliability as well as validity of the measurement. 67 healthy subject s were examined using the P300 dipole model in addition to the scalp data m easurement. The results show that P300 subcomponents reflect functionally d ifferent processes concerning age changes of P300 activities. Temporo-parie tal P300 is smaller in older subjects, whereas frontal P300 is not attenuat ed. Age affected both P300 subcomponents' latencies. Therefore, the functio nally different alteration of P300 subcomponents might be the reason for P3 00 topography changes with the P300 maximum more frontally in older age.