Cohort Differences in Cognitive Aging in the Longitudinal Aging Study Amsterdam

Abstract

ObjectivesThis study aims to examine cohort differences in cognitive performance and rates of change in episodic memory, processing speed, inductive reasoning, and general cognitive performance and to investigate whether these cohort effects may be accounted for by education attainment.MethodThe first cohort (N = 705) was born between 1920 and 1930, whereas the second cohort (N = 646) was born between 1931 and 1941. Both birth cohorts were aged 65 to 75 years at baseline and were followed up 3 and 6 years later. Data were analyzed using linear mixed models.ResultsThe later born cohort had better general cognitive performance, inductive reasoning, and processing speed at baseline, but cohort differences in inductive reasoning and general cognitive performance disappeared after adjusting for education. The later born cohort showed steeper decline in processing speed. Memory decline was steeper in the earlier born cohort but only from Time 1 to Time 3 when the same memory test was administered. Education did not account for cohort differences in cognitive decline.DiscussionThe later born cohort showed better initial performance in certain cognitive abilities, but no better preservation of cognitive abilities overtime compared with the earlier born cohort. These findings carry implications for healthy cognitive aging.

Comparison of cognitive and physical functioning of Europeans in 2004-05 and 2013

“…In our cross-sectional scenario, it was not possible to differentiate between the possible explanations, because higher starting levels would look like a postponement of cognitive decline. A recent longitudinal study from Amsterdam 38 suggests that it is the starting level and not postponement of cognitive decline that is the reason for better cognition among later-born elderly; however, the evidence is mixed from study to study. 39 …”

Spatial navigation deficits — overlooked cognitive marker for preclinical Alzheimer disease?

“…As a result, cognitive decline in healthy older people >75 years might have been considerably underestimated by longitudinal studies 32 . Moreover, delayed recall ability, one of the current main cognitive diagnostic indicators of AD, progressively declines in healthy adults aged ≥65 years 33 , highlighting the potential difficulties with the sensitivity of episodic memory to diagnose and predict AD pathophysiology in an older population. Similarly, as mentioned above, it is becoming increasingly recognised that patients with other forms of dementia can also show significant episodic memory problems.…”

Birth cohort differences in cognitive performance in 75- and 80-year-olds: a comparison of two cohorts over 28 years

“…Research on cohort differences in cognitive aging has mainly shown that later-born cohorts outperform earlierborn cohorts [3,[6][7][8][9][10][11][12][13]. The results depend on several factors, such as the cognitive domains assessed, participants' age range, the number of years between birth cohorts and whether studies have examined cohort differences in cognitive performance trajectories [14]. In a more recent study, Brailean et al [14] found that at the age 65 to 75 the laterborn cohort (1931)(1932)(1933)(1934)(1935)(1936)(1937)(1938)(1939)(1940)(1941) had better general cognitive performance, inductive reasoning and processing speed compared to the earlier-born cohort (1920)(1921)(1922)(1923)(1924)(1925)(1926)(1927)(1928)(1929)(1930).…”

“…The results depend on several factors, such as the cognitive domains assessed, participants' age range, the number of years between birth cohorts and whether studies have examined cohort differences in cognitive performance trajectories [14]. In a more recent study, Brailean et al [14] found that at the age 65 to 75 the laterborn cohort (1931)(1932)(1933)(1934)(1935)(1936)(1937)(1938)(1939)(1940)(1941) had better general cognitive performance, inductive reasoning and processing speed compared to the earlier-born cohort (1920)(1921)(1922)(1923)(1924)(1925)(1926)(1927)(1928)(1929)(1930). The cohort differences in general cognitive performance and inductive reasoning were explained by better education in the later cohort, but processing speed was not.…”