Prospective memory and subjective memory decline: A neuropsychological indicator of memory difficulties in community-dwelling older people

Introduction: Prospective memory difficulties are known to occur in Alzheimer's disease, and may provide an early indicator of cognitive decline. Older people reporting high levels of subjective memory decline (SMD) but without evidence of cognitive decline on standard neuropsychological tests are increasingly considered at increased risk for Alzheimer's disease. Therefore, the objective of this study was to investigate whether prospective memory performance is differentially impaired in older people reporting high levels of SMD as compared to a control group. Method: A total of 195 community-dwelling older adults (M-age=73.48years) were assessed for self-reported complaints of memory decline and allocated to either a group reporting high levels of SMD (SMD, n=96) or a healthy control group (HC, n=99). Groups were assessed on neuropsychological tests, an experimental prospective memory task (focal vs. nonfocal cue conditions), and a naturalistic prospective memory task. Results: The groups did not differ in performance on standard neuropsychological tests of working memory, executive attention, and episodic retrospective memory. Furthermore, on an experimental task of prospective memory (the Supermarket Shopping Trip task), although performance of both groups was better when cues for prospective memory were focal to the ongoing activity ((2)=.35), the SMD group were not impaired relative to the control group. On a naturalistic prospective memory task, however, there was a small but significant effect, with the SMD group performing more poorly than the HC group ((2)=.02). Conclusions: In older adults with high levels of SMD, naturalistic measures of prospective memory provide an approach to assessing memory performance that can offer a means of investigating the memory complaints of people with SMD. Identifying prospective memory difficulties in SMD also offers a focus for intervention.