[Age differences versus aging--a cross-sectional and longitudinal analysis on the development of memory in advanced...

This study examines the development of episodic memory in later adulthood and old age in a combined cross-sectional and longitudinal design. 124 normal aging subjects, aged 50-87 years, representing four age groups (M1 = 53.65 years, M2 = 60.60 years, M3 = 68.44 years, M4 = 75.83 years) participated in a cross-sectional study. Seven years later a retest was done in which 70% of the original sample again participated. Significant differences between the cross-sectional and the longitudinal results were found, with the latter showing the more severe decline in memory performances. Moreover, the age decline occurred earlier in the longitudinal study. Cohort differences account for these differences between the cross-sectional and longitudinal findings, favoring subjects of earlier-born cohorts.