| Abstract: | Four pigeons received periods of free food delivery alternating with periods of extinction. The experimental chamber was divided in half. Initially the subjects could produce stimuli selectively associated with these schedules by standing on the right side of the chamber and later by standing on the left side. In both phases, subjects produced the free food stimulus most of the time it was available but did not increase above baseline the time spent producing the extinction stimulus. Thus, when alternative stimuli are available, the pigeon prefers the stimulus associated with the greater frequency of reinforcement although the choice results in no biological advantage. |
