Training with Different Initial Set Sizes and Same/Different Concept Learning in Pigeons

Four groups of pigeons were trained initially with 8, 32, 64, and 1024 stimuli. Following transfer to novel stimuli, set sizes were successively doubled for each group to 1024 items. Learning rates (initial and overall) did not differ appreciably across groups. Initial transfer at successive set sizes varied directly with initial training set size (e.g. the 32-item group transfered better than the 8-item group at the 32-item set size and the 64-item group transfered better than the 32-item group at the 64-item set size). All groups achieved a high level of transfer and concept learning (~80 % correct) by the time they completed training with the 1024-item set. The results are discussed in terms of similarities and differences in how these four groups of pigeons learned the same/different task.