Age Differences in Flexibly Binding Memory of What, When and Where

Experiences are multimodal and often involve what, when and where aspects. Past research in young adults has shown that a core function of memory is to learn flexible associative structures connecting all three aspects. We investigated how normal cognitive aging affects multimodal memory associations and retrieval flexibility of partial or complete events. In two experiments, 63 younger (18–35 years) and 50 older adults (65–85) completed a spatio temporal object memory task in which they encoded object sequences appearing at different screen locations over repeated exposures, and then retrieved either object-only, location-only, or complete object-location sequences. In both age groups, memory for object sequences was best, followed by location sequences and object-location combinations, with older adults showing a disproportionately amplified pattern. Cross dimensional analyses showed that for both age-groups object-only sequence retrieval partially relied on location knowledge, and vice versa, suggesting that both age-groups used multimodal binding to scaffold sequence memory. Younger adults showed greater flexibility in modulating binding strength depending on retrieval demands, compared to older adults. Computational modeling revealed that a two-system model, assuming parallel learning of within-dimension transitions and cross-dimensional binding associations, adequately captured participants’ performance. Younger adults relied more on binding associations than transition learning, while older adults showed more balanced reliance. Our results indicate that reductions in binding flexibility contribute to adult age differences in remembering sequentially structured experiences.