The general aim of this proposal is to shed light on higher-order avian cognition, e.g., conceptual behavior and relational learning. The studies use same-different (S/D) discriminations to explore how pigeons extract categorical information from photographs of real objects and learn abstract relations. The first series of studies will present pictures of objects from the same or different views. If pigeons recognize the same object across sets of non-identical pictures, then object discrimination should proceed faster than view discrimination. The second series will employ the S/D alternation procedure in which pictures A and B (that are identical except for one change, e.g., omission of an object) are serially alternated with a brief interval between each picture. The ease with which subjects detect a difference will tell us how much attention is allocated to images of objects and how early in perception they are processed. The third series will train Ss to discriminate between two pairs of pictures in which each pair shares the same (AA versus CC; or AB versus CD) or different (AA versus CD) relation with each other. Though Premack has argued that only humans and language trained chimpanzees can make abstract S/D judgements, it is important to test this claim with a non-primate, non-symbol using species (e.g., the pigeon). A greater understanding of conceptual and relational learning in animals will increase our understanding of higher-order human cognition, contribute to the detection and development of treatments of cognitive disorders and facilitate ecologically valid educational practices.