Observing Response, Set-Size, and Abstract-Concept Formation by Pigeons

For pigeons learning a matching-to-sample task, abstract-concept learning can depend on the observing response requirement (Wright, 1997); but, its role in the two-item same/different procedure is unclear. In the present experiment, groups of pigeons with different observing response requirements (FR1, 10, and 20) to the sample item acquired a two-item same/different task with increasingly larger training set-sizes (8, 16, 32, 64, 128, 256, 1024). Transfer tests with novel items were conducted after each set-size expansion was acquired. Observing response influenced the rate of acquisition across set-size expansion: FR20 < FR10 < FR1. However, the observing response requirement did not affect transfer performance between groups and all pigeons fully learned the abstract concept (evidence by transfer being equivalent to baseline performance). These results suggest that the effect of set-size is independent from the observing response requirement for abstract-concept learning within the present parameters used in the two-item same/different procedure.