
Minimal cross-trial generalization in learning the representation of an odor-guided choice task
Author(s) -
Mingyu Song,
Yuji K. Takahashi,
Amanda C. Burton,
Matthew R. Roesch,
Geoffrey Schoenbaum,
Yaron Niv,
Angela Langdon
Publication year - 2022
Publication title -
plos computational biology/plos computational biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.628
H-Index - 182
eISSN - 1553-7358
pISSN - 1553-734X
DOI - 10.1371/journal.pcbi.1009897
Subject(s) - task (project management) , generalization , representation (politics) , cognitive psychology , odor , computer science , generative model , animal cognition , artificial intelligence , psychology , machine learning , generative grammar , cognition , mathematics , neuroscience , economics , mathematical analysis , management , politics , political science , law
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.