Hasz Brendan M, Redish A David
Graduate Program in Neuroscience, University of Minnesota Twin Cities Minneapolis, MN, United States.
Department of Neuroscience, University of Minnesota Twin Cities Minneapolis, MN, United States.
Front Integr Neurosci. 2018 Aug 3;12:30. doi: 10.3389/fnint.2018.00030. eCollection 2018.
Current theories suggest that decision-making arises from multiple, competing action-selection systems. Rodent studies dissociate deliberation and procedural behavior, and find a transition from procedural to deliberative behavior with experience. However, it remains unknown how this transition from deliberative to procedural control evolves within single trials, or within blocks of repeated choices. We adapted for rats a two-step task which has been used to dissociate model-based from model-free decisions in humans. We found that a mixture of model-based and model-free algorithms was more likely to explain rat choice strategies on the task than either model-based or model-free algorithms alone. This task contained two choices per trial, which provides a more complex and non-discrete per-trial choice structure. This task structure enabled us to evaluate how deliberative and procedural behavior evolved within-trial and within blocks of repeated choice sequences. We found that vicarious trial and error (VTE), a behavioral correlate of deliberation in rodents, was correlated between the two choice points on a given lap. We also found that behavioral stereotypy, a correlate of procedural automation, increased with the number of repeated choices. While VTE at the first choice point decreased [corrected] with the number of repeated choices, VTE at the second choice point did not, and only increased after unexpected transitions within the task. This suggests that deliberation at the beginning of trials may correspond to changes in choice patterns, while mid-trial deliberation may correspond to an interruption of a procedural process.
当前理论认为，决策源于多个相互竞争的行动选择系统。对啮齿动物的研究区分了深思熟虑行为和程序性行为，并发现随着经验的积累，会从程序性行为转变为深思熟虑行为。然而，在单次试验或重复选择的组块中，这种从深思熟虑控制到程序性控制的转变是如何演变的，仍然未知。我们为大鼠改编了一个两步任务，该任务已被用于区分人类基于模型的决策和无模型的决策。我们发现，与单独的基于模型或无模型算法相比，基于模型和无模型算法的混合更有可能解释大鼠在该任务上的选择策略。该任务每次试验包含两个选择，这提供了一个更复杂且非离散的每次试验选择结构。这种任务结构使我们能够评估深思熟虑行为和程序性行为在单次试验以及重复选择序列组块中的演变情况。我们发现，替代性试错（VTE），即啮齿动物深思熟虑行为的一种行为关联，在给定一圈的两个选择点之间具有相关性。我们还发现，行为刻板性，即程序性自动化的一种关联，随着重复选择次数的增加而增加。虽然第一个选择点的VTE随着重复选择次数的增加而[校正后]减少，但第二个选择点的VTE没有，并且仅在任务中出现意外转变后才增加。这表明试验开始时的深思熟虑可能对应于选择模式的变化，而试验中期的深思熟虑可能对应于程序性过程的中断。
