Older adults tend to have a broader vocabulary compared to younger adults – indicating a richer storage of semantic knowledge – but their retrieval abilities decline with age. Recent advances in quantitative methods based on network science have investigated the effect of aging on semantic memory structure. However, it is yet to be determined how this aging effect on semantic memory structure relates to its overall flexibility. Percolation analysis provides a quantitative measure of the flexibility of a semantic network, by examining how a semantic memory network is resistant to “attacks” or breaking apart. In this study, we incorporated percolation analyses to examine how semantic networks of younger and older adults break apart to investigate potential age-related differences in language production. We applied the percolation analysis to 3 independent sets of data (total N = 78 younger, 78 older adults) from which we generated semantic networks based on verbal fluency performance. Across all 3 datasets, the percolation integrals of the younger adults were larger than older adults, indicating that older adults' semantic networks were less flexible and broke down faster than the younger adults'. Our findings provide quantitative evidence for diminished flexibility in older adults' semantic networks, despite the stability of semantic knowledge across the lifespan. This may be one contributing factor to age-related differences in language production.

与年轻人相比，老年人往往拥有更广泛的词汇——表明语义知识的存储更丰富——但他们的检索能力随着年龄的增长而下降。基于网络科学的定量方法的最新进展研究了衰老对语义记忆结构的影响。然而，尚未确定这种对语义记忆结构的老化影响如何与其整体灵活性相关。渗透分析通过检查语义记忆网络如何抵抗“攻击”或分裂，提供了语义网络灵活性的定量测量。在这项研究中，我们结合渗透分析来检查年轻人和老年人的语义网络如何分解，以研究语言产生中潜在的与年龄相关的差异。N  = 78 名年轻人，78 名老年人），我们从中生成基于语言流畅性表现的语义网络。在所有 3 个数据集中，年轻人的渗透积分都大于老年人，这表明老年人的语义网络灵活性较差，并且比年轻人的崩溃更快。我们的研究结果为老年人语义网络的灵活性降低提供了定量证据，尽管语义知识在整个生命周期内都是稳定的。这可能是与年龄相关的语言生产差异的一个促成因素。