How do non-human primates represent others' awareness of where objects are hidden?

Area of Science:

• Cognitive Science
• Comparative Psychology
• Primate Cognition

Background:

• Non-human primates (NHPs) often predict knowledgeable agents' behavior, but the underlying cognitive mechanisms are unclear.
• Understanding when NHPs' representations of an agent's awareness fail is crucial for cognitive mechanism research.

Purpose of the Study:

• To investigate the conditions under which non-human primates' (NHPs) representations of an agent's awareness break down.
• To determine if geometric versus non-geometric object manipulations affect NHPs' expectations of an agent's goal-directed behavior.

Main Methods:

• Rhesus macaques observed an agent hide an object, then witnessed geometric (size/shape) or non-geometric (color) changes to the object while the agent was absent.
• Monkey looking times were measured as an indicator of expectation, particularly when the agent searched for the object after the manipulation.

Main Results:

• Monkeys looked longer when the agent searched incorrectly after a non-geometric (color) change, but not after a geometric (size/shape) change.
• NHPs did not expect the agent to search correctly following a geometric manipulation, even when the agent retained knowledge of the object's location.
• Experiment 3 confirmed monkeys perceived the color change, ruling out perceptual failure as the cause.

Conclusions:

• NHPs' expectations of knowledgeable agents' actions can be disrupted, supporting heuristic-based models of mental state attribution.
• Geometric changes outside an agent's perceptual field may more significantly impair NHPs' attribution of awareness compared to non-geometric changes.
• These findings advance our understanding of primate theory of mind and the factors influencing social cognition in non-human primates.