Abstract
In the present study, the mechanism of differential sample-responses was investigated by training pigeons to perform the same/different discrimination task. In Experiment I, the pigeons were taught for line-line matching-to-sample (MTS). Then they were given the same/different discrimination test (hue-line). The same relationship between differential sample behavior and correct comparison stimuli of MTS was provided to half the pigeons and the reversed one to the other. The result shows that the differential behavior controls the performance of the pigeons in the task. In Experiment II, the pigeons were divided into new two groups. The transfer test was conducted in each group. The group which met reversing differential sample-response requirements shows a significant drop to chance level. These results suggest that the same/different task is consisted of two processes: the differential sample-responses founded on sample stimuli and the choice between comparison stimuli corresponded to differential sample behavior. Its mechanism facilitates categorization of sample stimuli as well as gives the cue for the choices.
