Sixteen-year longitudinal and time lag changes in memory and cognition in older adults.

The authors describe assessment of 16-year changes in memory and intellectual abilities in a sample of 106 adults ages 30-36 and 55-81 at baseline. Results suggest that there are reliable 16-year declines in list and test recall but not in recognition after age 55. Comparisons of predictions of change from the cross-sectional baseline sample indicated that longitudinal changes were either similar to or greater than predicted for those participants over the age of 60. Despite age differences in initial scores, a comparison of 2 cohorts in a time lag analysis showed that they did not differ in performance when they were in their 70s. These results suggest that age changes in list and text recall in older adults are due to age-related declines rather than to cohort differences and that age declines in recognition are not reliable.