Functional relationships for determining similarities and differences in comparative cognition.

Area of Science:

• Comparative Cognition
• Animal Behavior
• Neuroscience

Background:

• Concept learning, the ability to generalize from learned examples to novel stimuli, is a fundamental cognitive process.
• Understanding the evolution and neural basis of concept learning requires comparative studies across species.

Purpose of the Study:

• To compare concept learning in pigeons (Columba livia) and two monkey species (capuchin and rhesus monkeys) using identical same/different tasks.
• To investigate how training set size influences novel-stimulus transfer and the eventual performance levels in these species.

Main Methods:

• Subjects were trained on same/different tasks with an expanding training set, starting with 8 items.
• Performance was assessed by measuring novel-stimulus transfer, reflecting the degree of concept learning.
• Different training set sizes (8, 32, 64, 128, 256 items) were employed.

Main Results:

• Both pigeons and monkeys showed increasing novel-stimulus transfer with larger training set sizes, indicating similar functional relationships in concept learning.
• Monkeys achieved baseline-equivalent transfer at a smaller set size (128 items) compared to pigeons (256 items).
• Pigeons trained with initial set sizes of 32 and 64 items showed improved transfer, matching monkey performance at those set sizes.

Conclusions:

• Pigeons and monkeys demonstrate comparable concept learning capabilities, with quantitative differences in the rate and scale of improvement.
• Species-specific factors, such as evolved neural systems and potential carryover effects from training, may explain the observed quantitative differences.
• The findings suggest that while higher-order cognitive abilities like concept learning show functional similarities, their implementation can vary across species.