In the present study, we investigated the accuracy of eyewitness accounts over time from a metacognitive perspective, in which post-retrieval monitoring and control processes play a crucial role in mediating between memory retrieval and ultimate memory performance. In two experiments, participants viewed a narrated slide show depicting ordinary daily events and were questioned about fine-grained event details, either immediately or after a delay (of either 24 or 48 h). High motivation for accurate responding was induced via monetary incentives (Exp. 1) or instructions (Exp. 2). Using Koriat and Goldsmith’s (1996) Quantity-Accuracy Profile methodology, we were able to isolate the cognitive and metacognitive components posited to underly free-report memory accuracy, and to examine them over time. Our results showed that, even under conditions of free-report and high motivation for accurate responding, the accuracy of memory reports declined substantially over time, largely due to reduced monitoring effectiveness (i.e., monitoring resolution) rather than to changes in control policy (i.e., report criterion). As predicted, the decline over time in confidence was more pronounced for true than for false memories, such that the metacognitive ability to differentiate between correct and incorrect answers deteriorated with time. This poorer monitoring resolution resulted in an increased proportion of errors among the volunteered responses, and consequently, in lower free-report accuracy. Our results shed light on the manner in which memory accuracy over time is affected by changes in the effectiveness of the metacognitive processes that operate during memory reporting.

中文翻译：

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目击者记忆准确性的认知和元认知决定因素

在本研究中，我们从元认知的角度研究了目击者陈述随时间变化的准确性，其中检索后的监视和控制过程在记忆检索和最终记忆性能之间起着至关重要的作用。在两个实验中，与会人员观看了叙述性幻灯片放映，描述了日常事件，并立即或延迟（24或48小时）询问了细粒度事件的详细信息。金钱激励（实验1）或指示（实验2）激发了做出准确回应的强烈动机。使用Koriat和Goldsmith（1996）的数量准确性描述在方法论上，我们能够分离出认知和元认知成分，这些成分被归因于自由报告记忆的准确性不足，并随着时间的推移对其进行了检查。我们的结果表明，即使在自由报告和对准确做出响应的积极性很高的条件下，内存报告的准确性也会随着时间的推移而显着下降，这主要是由于监控效果（即监控分辨率）降低而不是控制策略的变化（即，报告条件）。正如预测的那样，对真实性的信心随时间的下降比对虚假记忆的下降更为明显，因此区分正确答案和错误答案的元认知能力会随着时间而恶化。较差的监视分辨率导致自愿响应中错误的比例增加，因此，自由报告的准确性降低。