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.

适用于连续响应任务的扩散模型的循环模拟应用于连续结果源记忆任务。与将所有可变性归因于记忆响应的现有源检索模型相比，循环扩散模型将噪声分解为由记忆和决策过程引起的可变性。我们比较了三个模型：（1）单个扩散过程，漂移率在试验与试验之间存在差异，（2）两个扩散过程的混合，一个具有正漂移，在试验与试验之间没有变化，以及代表离散猜测的第二个零漂移过程，以及 (3) 混合模型，该模型将正漂移过程和零漂移过程与正漂移过程中的试验间可变性混合在一起。模型拟合与联合响应错误和响应时间 (RT) 数据的比较表明，在连续报告源记忆任务中，没有检索到任何信息的记忆强度阈值似乎是响应的基础。此外，我们还根据参与者对旧/新识别任务的信心对来源的反应进行了调节，排除了参与者猜测只是由于无法识别的项目的可能性。总体而言，我们的研究结果支持源记忆检索的全有或无或部分或无观点，并对源记忆的连续模型提出挑战。排除参与者猜测只是由于无法识别的项目的可能性。总体而言，我们的研究结果支持源记忆检索的全有或无或部分或无观点，并对源记忆的连续模型提出挑战。排除参与者猜测只是由于无法识别的项目的可能性。总体而言，我们的研究结果支持源记忆检索的全有或无或部分或无观点，并对源记忆的连续模型提出挑战。