Contents: Part I:Introduction.T.R. Zentall, Animal Cognition: An Approach to the Study of Animal Behavior. Part II:Stimulus Representation.W.K. Honig, The Stimulus Revisited: My, How You've Grown! A.A. Wright, When Is a Stimulus a Pattern? D.R. Thomas, Discriminative Stimulus Control: What You See Is Not Necessarily What You Get. E. Hearst, S. Sutton, Generalization Gradients of Excitation and Inhibition: Long-Term Memory for Dimensional Control and Curious Inversions During Repeated Tests with Reinforcement. P. Kraemer, N.E. Spear, Retrieval Processes and Conditioning. Part III:Memory Processes.D.C. Wright, When Memory Fails to Fail. W.A. Roberts, S. Mitchell, M.T. Phelps, Foraging in Laboratory Trees: Spatial Memory in Squirrel Monkeys. M.F. Brown, Sequential and Simultaneous Choice Processes in the Radial-Arm Maze. H.L. Roitblat, Representations and Processes in Working Memory. D.S. Grant, Coding Processes in Pigeons. T.R. Zentall, L.M. Sherburne, J.N. Steirn, Common Coding and Stimulus Class Formation in Pigeons. Part IV:Perceptual Processes.D.S. Olton, K. Pang, F. Merkel, H. Egeth, Attention: Neurocognitive Analyses. R.G. Cook, Gestalt Contributions to Visual Texture Discriminations by Pigeons. D.L. Chatlosh, E.A. Wasserman, Multidimensional Stimulus Control in Pigeons: Selective Attention and Other Issues. W.S. Maki, From Elementary Associations to Animal Cognition: Connectionist Models of Discrimination Learning. M. Rilling, L. LaClaire, M. Warner, A Comparative, Hierarchical Theory for Object Recognition and Action. S.H. Hulse, Absolutes and Relations in Acoustic Perception by Songbirds.