EEG and ERP assessment of normal aging.

EEG was recorded from 120 normal adult subjects who ranged in age from 20 to 80+ years in separate eyes open/closed conditions. The P3(00) event-related brain potential (ERP) was elicited with auditory and visual stimuli in separate conditions in the same subjects. Spectral analysis indicated that overall EEG power decreased as subject age increased. P3 amplitude decreased and peak latency increased for both the auditory and visual stimulus conditions as subject age increased. Few age-related differences were observed for the N1, P2, or N2 components. Spectral power from the delta, theta, and alpha bands correlated positively with P3 amplitude across subject age, but mean band frequency demonstrated only weak associations with P3 latency. No strong relationships were found between EEG and the other ERP component variables. The results suggest that age contributes to EEG power shifts, and that such changes significantly affect age-related variability of the P3 ERP component.