Autobiographical Memory in Healthy Aging: a Decade-long Longitudinal Study.

Abstract

Autobiographic memory (AM) - which is generally considered to be the most advanced human memory system - is subject to a myriad of psychological and neurobiological factors. We, therefore, examined AM longitudinally during the transition from midlife to young-old age and from young-old to old age in two birth cohorts (born 1930-1932 and 1950-1952) hence starting at age 55.14 ± 0.94 vs. 73.85 ± 0.96, respectively. Participants (n = 239) of the Interdisciplinary Longitudinal Study on Adult Development and Aging were recruited of whom 166 could be reexamined after 9 ± 0.9 years. AM was investigated for three periods of life using an established semi-structured interview; potential cognitive decline was assessed on a broad test battery. All subjects stayed cognitively healthy. Analysis of variance with repeated measures revealed age-related semantization effects with a significantly lower number of specific and thereby a higher number of general AMs exclusively from young-old to old age. This effect did not coincide with cognitive decline. In the follow-up period, a significant decrease of event-related details was significantly more pronounced in the young-old than in the old cohort and details were better recalled by the young than the old cohort. At baseline, this difference was significant for the recent past only but involved all periods at follow-up. According to our findings, AM changes in healthy aging accelerate during the transition from young-old to old age and may herald other cognitive deficits. Additionally, these AM changes in cognitively healthy subjects point at an economic process of adaptation.