Age-related changes in involuntary and voluntary attention as reflected in components of the event-related potential (ERP).

The present paper provides an overview of age-related changes in both involuntary and voluntary attention in adult subjects as manifested in scalp-recorded ERPs. A decline in orienting with old age was inferred from a substantial reduction with age in the magnitude of deviance-related ERP components like MMN, target as well as nontarget P3s, novelty P3 and N400. A review of focused attention studies further suggested that old and young subjects do not differ substantially in the quality of attentional operations. In old subjects early selection processes, as reflected in their selection potentials, have a somewhat slower onset than in young subjects, especially in conditions in which selection is based upon complex discrimination of stimulus features. Furthermore, the global pattern emerging from visual and memory search studies is that search-related negativities in the ERPs are smaller and of longer duration in old than in young subjects over the central and anterior scalp sites. These effects could indicate that controlled search is less intense or takes more time per search operation in old than in young subjects. At more posterior scalp sites there was tendency towards an enhanced search-related negativity that could reflect a specific difficulty (or compensatory increase in mental effort) of old subjects in spatially locating targets in complex visual fields.