Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, 21218, USA.
Department of Neuroscience, Johns Hopkins Medical School, Baltimore, MD, 21218, USA.
Nat Commun. 2019 May 14;10(1):2151. doi: 10.1038/s41467-019-10089-0.
Performance on cognitive tasks during learning is used to measure knowledge, yet it remains controversial since such testing is susceptible to contextual factors. To what extent does performance during learning depend on the testing context, rather than underlying knowledge? We trained mice, rats and ferrets on a range of tasks to examine how testing context impacts the acquisition of knowledge versus its expression. We interleaved reinforced trials with probe trials in which we omitted reinforcement. Across tasks, each animal species performed remarkably better in probe trials during learning and inter-animal variability was strikingly reduced. Reinforcement feedback is thus critical for learning-related behavioral improvements but, paradoxically masks the expression of underlying knowledge. We capture these results with a network model in which learning occurs during reinforced trials while context modulates only the read-out parameters. Probing learning by omitting reinforcement thus uncovers latent knowledge and identifies context- not "smartness"- as the major source of individual variability.
在学习过程中进行认知任务的表现被用来衡量知识，但由于这种测试容易受到上下文因素的影响，因此仍存在争议。在多大程度上，学习过程中的表现取决于测试环境，而不是潜在的知识？我们在一系列任务中对老鼠、大鼠和雪貂进行了训练，以研究测试环境如何影响知识的获取及其表达。我们在强化试验中穿插了探测试验，在探测试验中我们省略了强化。在所有任务中，每种动物在学习过程中的探测试验中表现得都明显更好，并且动物间的变异性明显降低。强化反馈对于与学习相关的行为改善至关重要，但矛盾的是，它掩盖了潜在知识的表达。我们使用一个网络模型来捕捉这些结果，在该模型中，学习发生在强化试验中，而上下文仅调节读出参数。通过省略强化来探测学习，从而揭示潜在的知识，并确定是上下文而不是“聪明”是个体变异性的主要来源。
