The oddity preference effect and the concept of difference in pigeons

Area of Science:

• Cognitive psychology
• Animal behavior
• Comparative cognition

Background:

• Nonmatching (oddity) tasks are learned faster than matching tasks, an effect known as the oddity preference.
• Pigeons trained on same/different (S/D) tasks learned abstract difference but didn't show the oddity preference effect.
• Previous studies suggest prior training influences abstract concept learning in pigeons.

Purpose of the Study:

• To investigate if experimentally naive pigeons exhibit the oddity preference effect in abstract concept learning.
• To determine if naive pigeons show faster acquisition and better transfer in nonmatching tasks compared to prior training conditions.
• To explore the influence of set size on abstract concept learning and transfer in pigeons.

Main Methods:

• Experimentally naive pigeons were trained on a nonmatching (oddity) task.
• Transfer to novel configurations was assessed across varying set sizes (3-item to 96-item sets).
• Performance was compared to previous studies involving match-to-sample (MTS) and S/D tasks.

Main Results:

• Naive pigeons showed the oddity preference effect, with above-chance transfer to novel configurations in the smallest set size.
• Transfer accuracy increased with set size, reaching equivalence with trained-stimulus performance at a 24-item set.
• An unusual set-size function with performance dips and rises suggests combined learning strategies.

Conclusions:

• Experimentally naive pigeons demonstrate the oddity preference effect in abstract concept learning.
• Pigeons can learn abstract difference, and this learning is influenced by set size and learning strategies.
• The findings suggest pigeons may employ a combination of item-specific and relational learning strategies for abstract concepts.