Comparing Concept Learning in Matching-to-Sample and Same/Different by Pigeons

Abstract concept learning in matching-to-sample and same/different tasks was compared using a set-size expansion procedure. In separate groups (matching-to-sample, same/different), training began with a small set size and was systematically doubled until a high level of concept learning was attained. To measure concept learning, transfer tests with novel stimuli were conducted after each set size increase. Transfer performance increased with set size. Matching-to-sample and same/different concept learning were compared by plotting transfer performance at each set size by the total number of display configurations with the training stimuli. Under the conditions of these experiments, the set-size functions were similar for both tasks. The processes of abstract concept learning in these two tasks are discussed in terms of their similar functions relating concept learning to set size and the high level of concept learning ultimately achieved by the subjects in both these tasks.