Mapping Core Memory Networks in Cognitively Impaired Adults Aged 75 and Older: Insights From a WMS-R-Based Symptom Network Analysis

Objective: This study employed a symptom network analysis to elucidate the interrelationships among key memory domains assessed by the Wechsler Memory Scale-Revised (WMS-R) in adults aged 75 and older with cognitive impairment. Our goal was to identify the central components within the memory network that may serve as promising targets for early and precision interventions. Methods: A total of 265 participants were recruited from a dementia center in Kyoto, Japan (2018–2022). Four WMS-R subtests—assessing verbal memory, visual memory, attention and concentration, and delayed recall—were administered. Spearman's rank-order correlations were used to explore pairwise associations. A sparse network structure was estimated using the EBICglasso regularization method in R, and centrality metrics (Strength, Betweenness, and Closeness) were calculated to determine the relative prominence of each domain. The robustness of the network was evaluated through extensive bootstrap analyzes. Results: The results revealed strong positive correlations among verbal memory, visual memory, and delayed recall, while attention and concentration were less strongly linked to the other domains. Network analysis consistently identified visual memory and delayed recall as the most central nodes—with the strongest edge observed between these two functions. Bootstrap procedures confirmed the stability and precision of the major edges and the strength centrality metric, although betweenness and closeness indices showed lower stability. Conclusion: Visual memory and delayed recall emerged as pivotal components in the cognitive network of older adults with impairment, suggesting that interventions focusing on these domains may enhance overall cognitive function.