Background: A number of cognitive aging models have been proposed to explain the age-related decline in several cognitive functions, but these models have rarely been examined together. We analyzed the contributions of four main models – processing resources, speed of processing, cognitive reserve and knowledge – to source memory decay related to the aging process.

Methods: A total of 1554 healthy adults between 21 and 80 years old participated in the study. Structural equation modeling was conducted on data from the whole sample and separately in the data from young, middle-aged and older adult age groups. To estimate each cognitive model, we measured working memory discrimination levels (processing resources), working memory reaction times (speed of processing), education (cognitive reserve) and vocabulary (knowledge).

Results: Processing resources mediate the effects of age on source memory across the adult lifespan, whereas speed of processing mediates these effects only in young adults, cognitive reserve only in middle-aged adults and knowledge only in older adults.

Conclusions: Processing resources was the cognitive model that most contributes to explaining source memory decay. The fact that the other models are relevant to specific age groups provides useful information to exploit their benefits to preserve source memory in specific life stages.

背景：已经提出了许多认知衰老模型来解释几种认知功能中与年龄有关的衰落，但是这些模型很少一起研究。我们分析了四个主要模型（处理资源，处理速度，认知储备和知识）对与衰老过程相关的内存衰减的贡献。

方法：共有1554名21至80岁的健康成年人参加了研究。对整个样本数据进行结构方程建模，并分别对年轻，中年和老年人组的数据进行结构方程建模。为了估计每个认知模型，我们测量了工作记忆的辨别水平（处理资源），工作记忆的反应时间（处理速度），教育程度（认知储备）和词汇量（知识）。

结果：加工资源介导了年龄对成年人整个寿命的影响，而加工速度仅在青壮年中介导了这些影响，仅在中年人中具有认知储备，而在老年人中则只有知识。

结论：处理资源是最有助于解释源记忆衰退的认知模型。其他模型与特定年龄组相关的事实提供了有用的信息，可以利用它们的优势来保存特定生命阶段中的源记忆。