First- and second-order configural sensitivity for greeble stimuli in baboons

Area of Science:

• Cognitive neuroscience
• Comparative psychology
• Primate behavior

Background:

• Nonhuman primates exhibit variable processing of facial stimuli's first- and second-order relational properties.
• Configural processing, crucial for face recognition, involves understanding spatial relationships within stimuli.

Purpose of the Study:

• To investigate configural processing in baboons using non-face stimuli (greebles).
• To determine if baboons can process both first- and second-order relational properties of visual stimuli.

Main Methods:

• Five baboons were trained on a two-alternative forced choice task with greeble stimuli.
• Testing involved greeble pairs with modifications in first-order (global spatial relations) and second-order (finer spatial relations) properties.

Main Results:

• Baboons performed above chance across all test conditions, including those relying solely on second-order cues.
• Performance was significantly higher for first-order relational stimuli compared to second-order stimuli.
• Extended training with greebles may facilitate the processing of second-order relational properties.

Conclusions:

• Configural sensitivity in baboons extends beyond facial stimuli to non-face objects like greebles.
• A common neural mechanism may underlie configural processing for both faces and non-face stimuli in baboons.
• These findings challenge the face-specific view of configural processing and highlight broader visual processing capabilities in primates.