People can learn that different events are interchangeable because they essentially "mean the same thing." Such "stimulus equivalences" are one means by which people can respond immediately and appropriately to new situations on the basis of learning and experience in other situations. This characteristic of behavior is often regarded as special, and maybe unique, to human beings. Is language necessary for this important behavioral attribute? If animals without language can learn stimulus equivalences, language is not necessary. Dr. Urcuioli, in collaboration with Dr. Thomas R. Zentall, of the University of Kentucky, will examine this question using pigeons as the experimental animal. Well-established training techniques and the excellent visual abilities of pigeons make them a most appropriate choice. The pigeons will first be taught that certain (visual) stimuli go with other (visual) stimuli. Later, they will be tested to see if, as a result of that training, they have learned that those stimuli belong to the same "group" or "class." To do this, they will be taught in a second phase to match new stimuli to some of the stimuli with which they were originally trained. Then, their ability to match the remaining training stimuli to the new ones introduced in the second phase will be measured. Successful performance during this latter (test) phase would show that pigeons, like humans, can form stimulus equivalences or stimulus classes. If this ability can be established, it would mean that human language is not necessary for this important behavioral attribute. It would also encourage scientists to study more intensively in the laboratory just how this supposedly special human characteristic comes about.
