Age effects on the P300 to novel somatosensory stimuli.

Event-related brain potentials (ERPs) to somatosensory task-relevant targets and task-irrelevant novel (tactile and shock) stimuli were studied in 30 subjects between the ages of 18 and 79. Target and novel P300 latencies increased linearly with age at comparable rates. P300 amplitudes and scalp topographies also changed with age. P300 amplitudes remained constant at frontal sites and decreased at central and parietal sites for both target and novel stimuli with increasing age. The current results extend the age-related novel P300 changes reported in the auditory and visual modalities to the somatosensory system. The age-related amplitude reduction at posterior scalp sites supports independent contributions of frontal and posterior association cortex to P300 generation.