Introduction ; Comparative Cognition: A Natural Science Approach to the Study of Animal Intelligence, Edward A. Wasserman and Thomas R. Zentall ; I. Perception and Illusion ; 1. Grouping and Segmentation of Visual Objects by Baboons (Papio papio) and Humans (Homo sapiens), Joel Fagot and Isabelle Barbet ; 2. Seeing What Is Not There: Illusion, Completion, and Spatio-Temporal Boundary Formation in Comparative Perspective, Kazuo Fujita ; 3. The Cognitive Chicken: Visual and Spatial Cognition in a Non-Mammalian Brain, Giorgio Vallortigara ; 4. The Comparative Psychology of Absolute Pitch, Ronald G. Weisman, Mitchel T. Williams, Jerome S. Cohen, Milan G. Njegovan, and Christopher B. Sturdy ; II. Attention and Search ; 5. Reaction-Time Explorations of Visual Perception, Attention, and Decision in Pigeons, Donald S. Blough ; 6. Selective Attention, Priming, and Foraging Behavior, Alan C. Kamil and Alan B. Bond ; 7. Attention as it is Manifest across Species, David A. Washburn and Lauren A. Taglialatela ; III. Memory Processes ; 8. The Questions of Temporal and Spatial Displacement in Animal Cognition, William A. Roberts ; 9. Memory Processing, Anthony A. Wright ; IV. Spatial Cognition ; 10. Arthropod Navigation: Ants, Bees, Crabs, Spiders Finding Their Way, Ken Cheng ; 11. Comparative Spatial Cognition: Processes in Landmark and Surface-Based Place Finding, Marcia L. Spetch and Debbie M. Kelly ; 12. Properties of Time-Place Learning, Donald M. Wilkie and Christina M. Thorpe ; V. Timing and Counting ; 13. Behavioristic, Cognitive, Biological, and Quantitative Explanations of Timing, Russell M. Church ; 14. Sensitivity to Time: Implications for the Representation of Time, Jonathon D. Crystal ; 15. Time and Number: Learning, Psychophysics, Stimulus Control, and Retention, J. Gregor Fetterman ; VI. Conceptualization and Categorization ; 16. Relational Discrimination Learning in Pigeons, Robert G. Cook and Edward A. Wasserman ; 17. A Modified Feature Theory as an Account of Pigeon Visual Categorization, Ludwig Huber and Ulrike Aust ; 18. Category Structure and Typicality Effects, Masako Jitsumori ; 19. Similarity and Difference in the Conceptual Systems of Primates: The Unobservability Hypothesis, Jennifer Vonk and Daniel J. Povinelli ; 20. Rule Learning, Memorization Strategies, Switching Attention Between Local and Global Levels of Perception, and Optimality in Avian Visual Categorization, Charles P. Shimp, Walter T. Herbranson, Thane Fremouw, Alyson L. Froehlich ; 21. Responses and Acquired Equivalence Classes, Peter J. Urcuioli ; VII. Pattern Learning ; 22. Spatial Patterns: Behavioral Control and Cognitive Representation, Michael F. Brown ; 23. The Structure of Sequential Behavior, Stephen B. Fountain ; 24. Truly Random Operant Responding: Results & Reasons, Greg Jensen, Claire Miller, and Allen Neuringer ; 25. The Simultaneous Chain: A New Look at Serially Organized Behavior, Herbert S. Terrace ; VIII. Tool Fabrication and Use ; 26. Cognitive Adaptations for Tool-Related Behaviour in New Caledonian Crows, Alex Kacelnik, Jackie Chappell, Ben Kenward, and Alex A. S. Weir ; 27. What is Challenging About Tool Use? The Capuchin's Perspective, Elisabetta Visalberghi and Dorothy Fragaszy ; IX. Problem Solving and Behavioral Flexibility ; 28. Intelligences and Brains: An Evolutionary Bird's Eye View, Juan D. Delius and Julia A. M. Delius ; 29. How Do Dolphins Solve Problems?, Stan A. Kuczaj II and Rachel Thames Walker ; 30. The Comparative Cognition of Caching, S. R. de Kort, S. Tebbich, J. M. Dally, N. J. Emery, and N. S. Clayton ; 31. The Neural Basis of Cognitive Flexibility in Birds, Shigeru Watanabe ; X. Social Cognition Processes ; 32. Chimpanzee Social Cognition in Early Life: Comparative-Developmental Perspective, Masaki Tomonaga, Masako Myowa-Yamakoshi, Yuu Mizuno, Sanae Okamoto, Masami K. Yamaguchi, Daisuke Kosugi, Kim A. Bard, Masayuki Tanaka, and Tetsuro Matsuzawa ; 33. Stimuli Signaling Rewards that Follow a Less Preferred Event are Themselves Preferred: Implications for Cognitive Dissonance, Thomas R. Zentall, Tricia S. Clement, Andrea M. Friedrich, and Kelly A. DiGian ; Epilogue: ; Postscript: An Essay on the Study of Cognition in Animals Stewart M. Hulse