Semantic Memory Functioning Across the Adult Life Span

Using data from the first wave of data collection in the Betula project, this research examined semantic memory performance in adulthood and old age (N = 1000). The Betula project is a 10-year longitudinal study on memory and health that involves participants from 10 age groups: 35,40, 45, ..., and 80 years of age. Results from tests of verbal fluency and vocabulary indicated no performance variation between 35 and 50 years of age, followed by a gradual deterioration with increasing age. In a test of general knowledge, only the two oldest cohorts showed deficits. When educational level was statistically controlled, a different pattern of results was seen: the middle-aged adults performed at the highest level and, with the exception of one fluency test, no age-related deficits were observed before 75 years of age. These results suggest that, although there may be age-related deficits in semantic memory in the general population, education appears to be a more important factor than adult age per se for semantic memory functioning. The data support the view that activation of preexisting memory representations is relatively unaffected by the adult aging process, and demonstrate the pivotal role of cultural factors (e.g., education, verbal experience) in proficient semantic memory functioning.