Effects of advancing age on the processing of semantic anomalies in adults: evidence from event-related brain potentials.

Age-related changes in the processing of sentence-embedded semantic anomalies were examined using auditory event-related potentials (ERPs). Semantically incongruous words elicited an N400 effect in middle-aged (50s: 55.6 years) and elderly (60s: 64.1 years) subjects, whereas in older elderly adults (70s: 74.9 years) this effect approached significance. N400 peak latencies were not delayed with advancing age; however, there was a reliable linear decrease in mean and peak amplitude, with slopes being similar to those previously reported for the visual N400 effect. A P600 effect was obtained in response to semantic anomalies and it was neither delayed in latency nor reduced in amplitude with advancing age. However, it was found to be larger over anterior sites in elderly and older elderly subjects.