Electrical sources of P300 event-related brain potentials revealed by low resolution electromagnetic tomography .1. Effects of normal aging

The P300 event-related potential (ERP) is considered to be closely related to cognitive processes. Previous reports regarding major generators contributing to the scalp-recorded P300 suggested widely distributed multiple sources. Based on ERPs recorded in 172 normal healthy subjects aged between 20 and 88 years in an auditory oddball paradigm, electrical activity in the brain corresponding to N1 and P300 components was localized by means of low resolution electromagnetic tomography (LORETA). The N1 LORETA generators, located in both auditory cortices, did not change over age. On the other hand, the P300 LORETA generators, located predominantly in the frontal neocortex and less pronounced in the posterior parietal cortex, decreased over age both in frontal and parietal source strength.