Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, Melbourne, VIC, 3052, Australia.
Psychon Bull Rev. 2021 Aug;28(4):1112-1130. doi: 10.3758/s13423-020-01862-0. Epub 2021 Jan 26.
A circular analogue of the diffusion model adapted for continuous response tasks is applied to a continuous-outcome source memory task. In contrast to existing models of source retrieval that attribute all of the variability in responding to memory, the circular diffusion model decomposes noise into variability arising from memory and from decision processes. We compared three models: (1) a single diffusion process with trial-to-trial variability in drift rate, (2) a mixture of two diffusion processes, one with positive drift that does not vary from trial-to-trial, and a second zero-drift process that represents discrete guessing, and (3) a hybrid model that mixed positive and zero-drift processes with trial-to-trial variability in the positive drift process. Comparison of model fits to joint response error and response-time (RT) data suggest that a memory strength threshold under which no information is retrieved appears to underlie responding in a continuous-report source memory task. Additionally, we also conditioned participants' source responding on their confidence in an old/new recognition task, ruling out the possibility that participant guessing was only due to unrecognized items. Overall, our findings support an all-or-none or some-or none view of source memory retrieval and pose a challenge to continuous models of source memory.
一种适用于连续反应任务的扩散模型的循环类比被应用于连续结果源记忆任务。与归因于记忆中所有可变性的现有源检索模型不同，循环扩散模型将噪声分解为来自记忆和决策过程的可变性。我们比较了三个模型：（1）一个具有每个试次间漂移率变化的单一扩散过程，（2）一个由两个扩散过程混合而成的模型，一个具有正漂移且不随试次变化的过程，以及一个表示离散猜测的零漂移过程，（3）一个混合了正漂移和零漂移过程的混合模型，其中正漂移过程具有每个试次间的变化。模型拟合到联合反应误差和反应时间（RT）数据的比较表明，在连续报告源记忆任务中，似乎存在一个记忆强度阈值，低于该阈值就无法检索信息。此外，我们还根据参与者在旧/新识别任务中的信心来调节他们的源反应，排除了参与者猜测仅仅是由于未被识别的项目的可能性。总的来说，我们的发现支持源记忆检索的全有或全无或有些或全无的观点，并对源记忆的连续模型提出了挑战。
