Adult age differences in direct and indirect tests of memory.

Indirect tests of memory assess the influence of recent experience on task performance without requiring awareness of remembering. Evidence concerning whether there are reliable age differences on such indicators of implicit memory has been inconsistent. This inconsistency may be related either to the low power of previous studies, or the contamination of indirect measures by conscious memory retrieval strategies. In a statistically powerful test of this question, indirect and direct tests of memory were administered to 584 adults from three age groups (19-36 years, 55-69 years, 70-86 years). Significant age differences in favor of the young were found on the indirect test as well as direct tests, suggesting that there are small but reliable age differences in implicit memory. Correlational analyses examining the relationship of memory performance to other cognitive variables indicated that the indirect test was supported by different components than the direct tests.