Multichannel auditory event-related brain potentials: Effects of normal aging on the scalp distribution of N1, P2, N2 and P300 latencies and amplitudes

Event-related potentials (ERPs) were recorded at 17 leads in an auditory oddball paradigm in 172 normal healthy subjects aged between 20 and 88 years. With advancing age, N1 latency increased parietally (0.12 ms/year), P2 latency increased frontally (0.34 ms/year) and N2 and P300 latencies increased all over the scalp (0.37 ms/year for P300). P300 latency/age relationship was curvilinear with accelerated latency increase in elderlies (0.35 ms/year for subjects below 60 years; versus 2.03 ms/year for subjects above 60 years). With advancing age, standard tone ERP amplitudes were enhanced frontally (0.03 mu V/year for N1; 0.07 mu V/year for P2), N2 amplitudes were attenuated frontally (0.11 mu V/year) and P300 amplitudes were attenuated parietally (0.15 mu V/year). Multichannel analysis demonstrated that ERP latencies and amplitudes depended on electrode location. Standard tone ERP latencies changed their topographic distribution with age, whereas target tone ERP latencies did not. While N1 amplitude distribution was unaffected by age, P2 N2 and P300 topography changed significantly with age: P2 topography to a more frontal distribution and increased 'global field power'; N2 topography to a more parietal distribution; P300 topography to a more frontal and more equipotential distribution. Thus specific age effects on different ERP components were confirmed.