Serial learning by rhesus monkeys: II. Learning four-item lists by trial and error

Area of Science:

• Animal Cognition
• Behavioral Neuroscience
• Primate Learning

Background:

• Previous studies trained monkeys on lists by adding items sequentially.
• This created a need to investigate learning with all list items presented simultaneously.

Purpose of the Study:

• To train rhesus macaques to learn novel 4-item serial lists where all items were visible from the start.
• To understand the learning mechanisms, specifically trial-and-error strategies, involved in this task.

Main Methods:

• Three rhesus macaques were trained on novel 4-item lists (A-->B-->C-->D) with all items displayed initially.
• Subjects learned through trial and error, with errors terminating the trial and correct responses to intermediate items allowing continuation.
• A correct response to the final item (D) resulted in food reward.

Main Results:

• Despite a low chance probability (.04) of success, each monkey successfully mastered four novel 4-item lists.
• Learning involved recalling the consequences of correct and incorrect responses to each item in the sequence.

Conclusions:

• Rhesus macaques can learn novel serial lists presented all at once using a trial-and-error strategy.
• This study provides a foundation for investigating the development of serial expertise in non-human primates.