Modelling longitudinal changes in older adults' memory for spoken discourse: Findings from the ACTIVE cohort

Abstract

Episodic memory shows substantial declines with advancing age, but research on longitudinal trajectories of spoken discourse memory (SDM) in older adulthood is limited. Using parallel process latent growth curve models, we examined 10 years of longitudinal data from the no-contact control group (N = 698) of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) randomised controlled trial in order to test (1) the degree to which SDM declines with advancing age, (2) the predictors of these age-related declines and (3) the within-person relationship between longitudinal changes in SDM and longitudinal changes in fluid reasoning and verbal ability over 10 years, independent of age. Individuals who were younger, were White, had more years of formal education, were male and had better global cognitive function and episodic memory performance at baseline demonstrated greater levels of SDM on average. However, only age at baseline uniquely predicted longitudinal changes in SDM, such that declines accelerated with greater age. Independent of age, within-person decline in reasoning ability over the 10-year study period was substantially correlated with decline in SDM (r = .87). An analogous association with SDM did not hold for verbal ability. The findings suggest that longitudinal declines in fluid cognition are associated with reduced spoken language comprehension. Unlike findings from memory for written prose, preserved verbal ability may not protect against developmental declines in memory for speech.

Keywords:

• Discourse memory
• Aging
• Language comprehension
• Individual differences
• Latent growth curve modelling

This research was supported by a series of grants awarded from the National Institutes of Health to the six field sites and the coordinating center for the ACTIVE study, including The Hebrew Rehabilitation Center for the Aged [R01 NR04507]; The Indiana University School of Medicine [R01 NR04508]; The Johns Hopkins University [R01 AG14260]; The New England Research Institutes [R01 AG14282]; The Pennsylvania State University [R01 AG14263]; The University of Alabama at Birmingham [R01 AG14289]; and Wayne State University [R01 AG014276]. The first author was supported by an NIH training grant [T32-HD055272] and by NIH R01 AG13935 during the preparation of this manuscript.

This research was supported by a series of grants awarded from the National Institutes of Health to the six field sites and the coordinating center for the ACTIVE study, including The Hebrew Rehabilitation Center for the Aged [R01 NR04507]; The Indiana University School of Medicine [R01 NR04508]; The Johns Hopkins University [R01 AG14260]; The New England Research Institutes [R01 AG14282]; The Pennsylvania State University [R01 AG14263]; The University of Alabama at Birmingham [R01 AG14289]; and Wayne State University [R01 AG014276]. The first author was supported by an NIH training grant [T32-HD055272] and by NIH R01 AG13935 during the preparation of this manuscript.

Notes

¹ These estimates were calculated as the ratio of the model-estimated retest effect and the model-estimated cross-sectional age-related effect. The ratio describes the magnitude of the retest effect relative to the effect of age on cognition.