Abstract

Metacognitive awareness of abstract rules in rhesus macaques: Monkeys learn abstract rules, and they know it

Rohini Murugan1,2, Angelle Antoun1,2, Kathleen J. Bostick2, Tristan S. Correa2, and Benjamin Wilson1,2

1 Department of Psychology, Emory University, 2 Emory National Primate Research Center

Humans readily apply abstract rules in areas as diverse as language, music, mathematics and logic. Nonhuman animals have also been shown to learn abstract rules. However, questions remain about how these rules are represented in the minds of animals. Here we ask whether rhesus macaques acquire implicit or explicit knowledge of abstract rules by testing if they are metacognitive when applying these rules. Monkeys were trained on a waiting time paradigm, in which they had to maintain a response (a touch on a touchscreen computer) for a variable waiting time (5-12 seconds) to receive a reward. This was then combined with a three-alternative forced-choice abstract rule task, which they had previously learned. If monkeys are metacognitive in applying these abstract rules and know when they respond correctly, they should wait longer on trials when they make a correct decision, and pre-emptively abort trials when they are incorrect. Our data support this prediction, demonstrating metacognition, and therefore explicit knowledge, of macaques’ decisions based on abstract rules.