Department of Psychology, Syracuse University, Syracuse, NY, USA.
Department of Psychology, College of Letters and Science, University of Wisconsin-Madison, Madison, WI, USA.
Sci Rep. 2023 Dec 18;13(1):22528. doi: 10.1038/s41598-023-49858-9.
As people age, they learn and store new knowledge in their semantic memory. Despite learning a tremendous amount of information, people can still recall information relevant to the current situation with ease. To accomplish this, the mind must efficiently organize and search a vast store of information. It also must continue to retrieve information effectively despite changes in cognitive mechanisms due to healthy aging, including a general slowing in information processing and a decline in executive functioning. How effectively does the mind of an individual adjust its search to account for changes due to aging? We tested 746 people ages 25 through 69 on a semantic fluency task (free listing animals) and found that, on average, retrieval follows an optimal path through semantic memory. Participants tended to list a sequence of semantically related animals (e.g., lion, tiger, puma) before switching to a semantically unrelated animal (e.g., whale). We found that the timing of these transitions to semantically unrelated animals was remarkably consistent with an optimal strategy for maximizing the overall rate of retrieval (i.e., the number of animals listed per unit time). Age did not affect an individual's deviation from the optimal strategy given their general performance, suggesting that people adapt and continue to search memory optimally throughout their lives. We argue that this result is more likely due to compensating for a general slowing than a decline in executive functioning.
随着年龄的增长，人们在语义记忆中学习和存储新知识。尽管学习了大量的信息，但人们仍然可以轻松地回忆与当前情况相关的信息。为了实现这一点，大脑必须有效地组织和搜索大量的信息。它还必须继续有效地检索信息，尽管由于健康衰老导致认知机制发生变化，包括信息处理速度普遍减慢和执行功能下降。个体的思维在多大程度上能有效地调整搜索以适应因衰老而产生的变化？我们在语义流畅性任务（自由列举动物）上测试了 746 名年龄在 25 岁至 69 岁之间的人，发现平均而言，检索遵循语义记忆中的最佳路径。参与者倾向于按语义相关的动物序列（例如，狮子、老虎、美洲狮）进行列表，然后再切换到语义不相关的动物（例如，鲸鱼）。我们发现，这些与语义不相关的动物的转变时间与最大化整体检索速度（即单位时间内列出的动物数量）的最佳策略非常吻合。年龄并没有影响个体在总体表现不佳时偏离最佳策略的程度，这表明人们在一生中会适应并继续以最佳方式搜索记忆。我们认为，这一结果更可能是由于补偿一般的减速，而不是执行功能的下降。
