Minimal cross-trial generalization in learning the representation of an odor-guided choice task.
Minimal cross-trial generalization in learning the representation of an odor-guided choice task.
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DOI：
10.1371/journal.pcbi.1009897
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发表时间：
2022-03
影响因子：
4.3
通讯作者：
Langdon AJ
中科院分区：
文献类型：
--
作者：
Song M;Takahashi YK;Burton AC;Roesch MR;Schoenbaum G;Niv Y;Langdon AJ
没有单一的方法来表示任务。事实上，尽管经历相同的任务事件和突发事件，不同的主体可能会形成不同的任务表征。作为实验者，我们经常假设受试者代表了我们设想的任务。然而，这种表示不能被视为理所当然，特别是在动物实验中，我们无法提供有关任务结构的明确指令。在这里，我们测试了老鼠如何代表气味引导的选择任务，其中两种气味提示表明两种反应中的哪一种会导致奖励，而第三种气味则表明两种反应之间的自由选择。简约的任务表示将允许动物从强制试验中学习在自由选择试验中选择什么是更好的选择。然而，动物不一定以这种方式概括气味。我们将使用不同任务表征的强化学习模型与执行该任务的个体大鼠逐次试验的选择行为进行拟合，并量化每只动物使用更简约表征的程度，从而在试验类型中进行推广。模型比较表明，尽管经验丰富，但大多数老鼠并未获得这种表征。我们的结果证明了正式测试能够提供观察到的行为的可能任务表征的重要性，而不是假设动物的任务表征遵守控制实验设计的生成任务结构。为了研究动物如何学习和做出决定，科学家设计实验，训练动物进行实验，并观察它们的行为方式。在这个过程中，一个重要但很少被问到的问题是动物如何理解实验。仅通过观察动物在任务中的行为，通常很难确定它们是否以实验者期望的方式理解任务。假设动物代表的任务与实际不同，可能会导致对行为或神经结果的错误解释。在这里，我们从这些替代模型解释动物选择行为的程度方面比较了简单奖励学习任务的不同可能表示。我们发现，老鼠并没有以最简约的方式代表任务，因此无法从强制选择试验中了解到自由选择试验中可以获得哪些奖励，尽管对这项任务进行了广泛的训练。这些结果提醒我们不要简单地假设动物对任务的理解与任务的设计方式相对应。
There is no single way to represent a task. Indeed, despite experiencing the same task events and contingencies, different subjects may form distinct task representations. As experimenters, we often assume that subjects represent the task as we envision it. However, such a representation cannot be taken for granted, especially in animal experiments where we cannot deliver explicit instruction regarding the structure of the task. Here, we tested how rats represent an odor-guided choice task in which two odor cues indicated which of two responses would lead to reward, whereas a third odor indicated free choice among the two responses. A parsimonious task representation would allow animals to learn from the forced trials what is the better option to choose in the free-choice trials. However, animals may not necessarily generalize across odors in this way. We fit reinforcement-learning models that use different task representations to trial-by-trial choice behavior of individual rats performing this task, and quantified the degree to which each animal used the more parsimonious representation, generalizing across trial types. Model comparison revealed that most rats did not acquire this representation despite extensive experience. Our results demonstrate the importance of formally testing possible task representations that can afford the observed behavior, rather than assuming that animals’ task representations abide by the generative task structure that governs the experimental design. To study how animals learn and make decisions, scientists design experiments, train animals to perform them, and observe how they behave. During this process, an important but rarely asked question is how animals understand the experiment. Merely through observing animals’ behavior in a task, it is often hard to determine if they understand the task in the same way as the experimenter expects. Assuming that animals represent tasks differently than they actually do may lead to incorrect interpretations of behavioral or neural results. Here, we compared different possible representations for a simple reward-learning task in terms of how well these alternative models explain animal’s choice behavior. We found that rats did not represent the task in the most parsimonious way, thereby failing to learn from forced-choice trials what rewards are available on free-choice trials, despite extensive training on the task. These results caution against simply assuming that animals’ understanding of a task corresponds to the way the task was designed.
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影响因子：
5
作者：
Bennett, Daniel;Niv, Yael;Langdon, Angela J.
通讯作者：
Langdon, Angela J.
影响因子：
3
作者：
Gershman, Samuel J.;Jones, Carolyn E.;Niv, Yael
通讯作者：
Niv, Yael
影响因子：
16.2
作者：
Roesch, Matthew R.;Taylor, Adam R.;Schoenbaum, Geoffrey
通讯作者：
Schoenbaum, Geoffrey
DOI：
10.1126/science.aar8644
发表时间：
2018-07-13
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Sweis BM;Abram SV;Schmidt BJ;Seeland KD;MacDonald AW 3rd;Thomas MJ;Redish AD
通讯作者：
Redish AD
影响因子：
5.3
作者：
Niv, Yael;Edlund, Jeffrey A.;O'Doherty, John P.
通讯作者：
O'Doherty, John P.