Metamemory in tufted capuchin monkeys (Cebus apella)

Area of Science:

• Cognitive Neuroscience
• Primate Behavior
• Animal Cognition

Background:

• Metacognition evidence is robust in great apes and Old World monkeys, but less so in New World monkeys.
• Capuchin monkeys have previously shown limitations in recognizing their own knowledge, impacting metacognitive assessment.

Purpose of the Study:

• To investigate whether tufted capuchin monkeys exhibit flexible behavioral changes based on memory trace strength.
• To assess the presence and nature of metamemory in New World monkeys using a delayed matching-to-sample task.

Main Methods:

• A modified 9-alternative delayed matching-to-sample (DMTS) task with varying delays was administered to two tufted capuchin monkeys.
• Monkeys could choose to attempt a memory test or escape it; in other trials, they were forced to take the test.
• Experiment 2 introduced no-sample trials, and Experiment 3 involved choosing between shape or texture matching tasks.

Main Results:

• Both monkeys preferentially escaped memory tests when their accuracy on forced tests was lower, indicating sensitivity to performance.
• One monkey demonstrated superior performance, with memory accuracy decreasing slower with delay and being higher in chosen than forced tests.
• This monkey also declined memory tests more often in no-sample trials and showed no difference in accuracy between chosen task types.

Conclusions:

• Tufted capuchin monkeys exhibit a form of metamemory, allowing them to assess the strength of their memory traces.
• The observed metamemory appears to function as a signal of memory strength rather than a detailed representation.
• This study provides evidence for metacognitive capabilities in New World monkeys, expanding our understanding of primate cognition.