de Jong Joost, Wilhelm Sophia, Akyürek Elkan G
Experimental Psychology, University of Groningen, Grote Kruisstraat 2/1, Groningen, the Netherlands.
Psychon Bull Rev. 2024 Dec;31(6):2704-2713. doi: 10.3758/s13423-024-02507-2. Epub 2024 May 8.
Working memory is known to be capacity-limited and is therefore selective not only for what it encodes but also what it forgets. Explicit forgetting cues can be used effectively to free up capacity, but it is not clear how working memory adaptively forgets in the absence of explicit cues. An important implicit cue that may tune forgetting in working memory is the passage of time. When information becomes irrelevant more quickly, working memory should also forget information more quickly. In three delayed-estimation experiments, we systematically manipulated how probing probability changed as time passed on after encoding an item (i.e., the "probing hazard"). In some blocks, probing hazard decreased after encoding an item, requiring participants to only briefly retain the memory item. In other blocks, the probing hazard increased or stayed flat, as the retention interval was lengthened. In line with our hypothesis, we found that participants adapted their forgetting rate to the probing dynamics of the working memory task. When the memory item quickly became irrelevant ("decreasing" probing hazard), forgetting rate was higher than in blocks where probing hazard increased or stayed flat. The time course of these adaptations in forgetting implies a fast and flexible mechanism. Interestingly, participants could not explicitly report the order of conditions, suggesting forgetting is implicitly sped up. These findings suggest that implicit adaptations to the temporal structure of our environment tune forgetting speed in working memory, possibly contributing to the flexible allocation of limited working memory resources.
已知工作记忆容量有限，因此它不仅对编码的内容具有选择性，对遗忘的内容也具有选择性。明确的遗忘线索可以有效地用于释放容量，但尚不清楚工作记忆在没有明确线索的情况下如何适应性地遗忘。一个可能调节工作记忆中遗忘的重要隐性线索是时间的流逝。当信息更快地变得无关紧要时，工作记忆也应该更快地遗忘信息。在三个延迟估计实验中，我们系统地操纵了在对一个项目进行编码后，探测概率如何随着时间的推移而变化（即“探测风险”）。在一些实验块中，编码一个项目后探测风险降低，要求参与者仅短暂保留记忆项目。在其他实验块中，随着保持间隔的延长，探测风险增加或保持不变。与我们的假设一致，我们发现参与者根据工作记忆任务的探测动态调整了他们的遗忘率。当记忆项目很快变得无关紧要时（“降低”探测风险），遗忘率高于探测风险增加或保持不变的实验块。这些遗忘适应的时间进程意味着一种快速且灵活的机制。有趣的是，参与者无法明确报告条件的顺序，这表明遗忘在隐性层面上被加速了。这些发现表明，对我们环境的时间结构的隐性适应调节了工作记忆中的遗忘速度，这可能有助于有限工作记忆资源的灵活分配。
