Examining the extents of same/different processing in non-human animals

Several animal species have demonstrated same/different concept learning. In the case of the pigeon, that concept has been investigated through multiple distinct methodologies. These approaches to same/different learning have each been evaluated thoroughly for their support of concept transfer and the nature of their controlling features. This now extensive literature has the distinct limitation that the breadth of same/different concept learning has not been compared by looking at transfer between these methodologies. Towards this end of examining the general abstractness of same/different concepts, we discuss several methods for exploring relationships between the same/different concepts from these diverse paradigms and the possible existence of modality-independent same/different representations.