Avoidance behavior is a typically adaptive response performed by an organism to avert harmful situations. Individuals differ remarkably in their tendency to acquire and perform new avoidance behaviors, as seen in anxiety disorders where avoidance becomes pervasive and inappropriate. In rodent models of avoidance, the inbred Wistar-Kyoto (WKY) rat demonstrates increased learning and expression of avoidance compared to the outbred Sprague Dawley (SD) rat. However, underlying mechanisms that contribute to these differences are unclear. Computational modeling techniques can help identify factors that may not be easily decipherable from behavioral data alone. Here, we utilize a reinforcement learning (RL) model approach to better understand strain differences in avoidance behavior. An actor-critic model, with separate learning rates for action selection (in the actor) and state evaluation (in the critic), was applied to individual data of avoidance acquisition from a large cohort of WKY and SD rats. Latent parameters were extracted, such as learning rate and subjective reinforcement value of foot shock, that were then compared across groups. The RL model was able to accurately represent WKY and SD avoidance behavior, demonstrating that the model could simulate individual performance. The model determined that the perceived negative value of foot shock was significantly higher in WKY than SD rats, whereas learning rate in the actor was lower in WKY than SD rats. These findings demonstrate the utility of computational modeling in identifying underlying processes that could promote strain differences in behavioral performance.

回避行为是生物体为避免有害情况而执行的典型适应性反应。个体在获得和执行新的回避行为的倾向上存在显着差异，正如在回避变得普遍和不适当的焦虑症中所见。在啮齿动物回避模型中，与远交 Sprague Dawley (SD) 大鼠相比，近交 Wistar-Kyoto (WKY) 大鼠表现出更多的学习和回避表达。然而，导致这些差异的潜在机制尚不清楚。计算建模技术可以帮助识别仅从行为数据中无法轻易解读的因素。在这里，我们利用强化学习 (RL) 模型方法来更好地理解回避行为中的应变差异。演员-评论家模特，具有单独的动作选择（在演员中）和状态评估（在评论家中）的学习率，被应用于来自大量 WKY 和 SD 大鼠的回避获取的个体数据。提取潜在参数，例如足部休克的学习率和主观强化值，然后在各组之间进行比较。RL 模型能够准确地表示 WKY 和 SD 回避行为，表明该模型可以模拟个人表现。该模型确定，WKY 大鼠足部电击的感知负值显着高于 SD 大鼠，而 WKY 的演员的学习率低于 SD 大鼠。这些发现证明了计算建模在识别可能促进行为表现中应变差异的潜在过程方面的效用。