Do Subjective Memory Complaints Lead or Follow Objective Cognitive Change? A Five-Year Population Study of Temporal Influence

Abstract

The relationship between subjective memory complaints (SM) and objective memory (OM) performance in aging has been variably characterized in a substantial literature, to date. In particular, cross-sectional studies often observe weak or no associations. We investigated whether subjective memory complaints and objectively measured cognition influence each other over time, and if so, which is the stronger pathway of change-objective to subjective, or subjective to objective-or whether they are both important. Using bivariate latent change score modeling in data from a population study (N=1980) over 5 annual assessment cycles, we tested four corresponding hypotheses: (1) no coupling between SM and OM over time; (2) SM as leading indicator of change in OM; (3) OM as leading indicator of change in SM; (4) dual coupling over time, with both SM and OM leading subsequent change in the other. We also extended objective cognition to two other domains, language and executive functions. The dual-coupling models best fit the data for all three objective cognitive domains. The SM-OM temporal dynamics differ qualitatively compared to other domains, potentially reflecting changes in insight and self-awareness specific to memory impairment. Subjective memory and objective cognition reciprocally influence each other over time. The temporal dynamics between subjective and objective cognition in aging are nuanced, and must be carefully disentangled to shed light on the underlying processes.

Keywords: Age-related memory disorders (MeSH); Aging; Anosognosia; Epidemiology; Latent change score modeling; Meta-cognition.

Figure 1

Path diagram of dual latent change score model. X = Subjective memory; Y = Objective cognition [Objective memory (OM), Objective language (OL), & Objective executive functions (OEF), respectively]

Figure 2

Vector field plots for subjective memory and objective memory. The plots illustrate the dynamic relationships between the paired variables. For a given pair of subjective and objective cognitive scores, the arrow indicates the expected changes in both subjective and objective cognition at the next measurement occasion. The direction of the arrows indicates whether future changes will be negative, positive, or neutral and the relative size of the arrow relates to the relative size of predicted changes.

Figure 3

Vector field plots for subjective memory and objective language.

Figure 4

Vector field plots for subjective memory and objective executive functions.