How Retrieval Processes Change With Age: Exploring Age Differences in Semantic Network and Retrieval Dynamics

This study investigated the impact of age on semantic memory networks and retrieval dynamics using a single-list free recall paradigm, involving 318 participants. The younger group, with 175 participants aged 25–55 years (M = 46.68 years; SD = 10.69), and the older group, consisting of 143 participants aged 61–88 years (M = 68.71 years; SD = 6.09), completed a word recall test to assess delayed recall performance. Semantic memory networks were constructed from recall data by analyzing the co-occurrence and sequence of recalled words. We observed significant differences in network structure, where the older group displayed higher average shortest path length and modularity values, indicative of less integrated networks, while the younger group exhibited a higher clustering coefficient, suggesting a more interconnected network. In terms of retrieval dynamics, both groups showed a temporal contiguity effect with forward asymmetry. However, this effect was less pronounced in older adults. The study also identified participants that diverted from the average dynamic curves: one subgroup relied on nontemporal mechanisms, and the other employed a backward direction in memory search. Participants utilizing forward temporal associations demonstrated the highest recall performance. Overall, our findings suggest that lower free recall performance in older adults may be related to a diminished capacity to reinstate temporal context for retrieval and distinct differences in their semantic memory network structure. Specifically, older adults appear to exhibit networks with a less flexible, small-world-like structure.