[Conditional discrimination using 3-dimensional objects by a chimpanzee (Pan troglodytes): tests for derived stimulus...

Area of Science:

• Primate cognition
• Animal behavior
• Comparative psychology

Background:

• Chimpanzees (Pan troglodytes) are key subjects for understanding cognitive evolution.
• Investigating derived stimulus relations in non-human primates offers insights into complex reasoning.
• Previous research indicates variable evidence for emergent symmetry in chimpanzees.

Purpose of the Study:

• To examine the emergence of derived stimulus relations, specifically symmetry, in a chimpanzee.
• To assess the impact of spatial arrangement changes on symmetry acquisition.
• To evaluate transitivity and symmetry under conditions with common actions.

Main Methods:

• A female chimpanzee was trained on a conditional-discrimination task using 3D objects in a face-to-face setting.
• Experiment 1 involved constructing paired-objects with specific actions, followed by symmetry testing with altered spatial arrangements.
• Experiment 2 tested transitivity and symmetry with a common action across all stimuli.

Main Results:

• The chimpanzee demonstrated emergent symmetry only when spatial arrangements differed between baseline and test trials.
• Significant above-chance performance was observed in the transitivity test in Experiment 2.
• Symmetry tests in Experiment 2 did not yield significant above-chance performance.

Conclusions:

• The findings suggest that chimpanzees exhibit weak evidence for emergent symmetry, which is sensitive to changes in stimulus presentation.
• Spatial context appears to play a crucial role in the emergence of symmetry in this species.
• The results align with prior studies indicating limited symmetry in chimpanzee cognitive repertoires.