Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis


Arts and Sciences



First Advisor

Dr. Thomas Zentall


With humans, a distinction can be made between explicit and implicit learning. language can be used to describe rule-based learning commonly seen in explicit, but not implicit learning. Unfortunately, we cannot do so with animals. Therefore, a non-verbal paradigm is needed to differentiate the types of learning. One method to make such a distinction is by training animals under a conditional discrimination task such as matching-to-sample with reinforcement delayed until a choice is made on the next trial: otherwise known as a 1-back procedure. In this experiment an alternating matching/mismatching to sample task under a 1-back schedule of reinforcement was used to determine if pigeons can demonstrate explicit learning. Pigeons were trained on red-green matching, and blue-yellow mismatching. Trials would randomly begin with either a matching or mismatching sample stimulus and would alternate every trial. Reinforcement was delivered under a 1-back schedule in which reinforcement only occurred on trial N if the response on trial N-1 was correct. Despite the delayed reinforcement schedule, pigeons showed significant levels of learning. However, given that the learning was slow and gradual it is unlikely that subjects learned the task explicitly.

Digital Object Identifier (DOI)