1. Addition versus deletion as a signal

   • Eliot Hearst
   • William T. Wolff

   OriginalPaper Pages: 120 - 133

2. Discrimination of relative numerosity by pigeons

   • W. K. Honig
   • Karen E. Stewart

   OriginalPaper Pages: 134 - 146

3. Pigeons’ memory for event duration: Intertrial interval and delay effects

   • Marcia L. Spetch
   • Benjamin Rusak

   OriginalPaper Pages: 147 - 156

4. Error analysis of delayed response in aged squirrel monkeys

   • James E. King
   • Raenel R. Michels

   OriginalPaper Pages: 157 - 162

5. Pigeons discriminate pictures of a geographic location

   • Donald M. Wilkie
   • Robert J. Willson
   • Shayne Kardal

   OriginalPaper Pages: 163 - 171

6. Interaction of sample dimension and sample-comparison mapping on pigeons’ performance of delayed conditional discriminations

   • Thomas R. Zentall
   • Peter J. Urcuioli
   • Pamela Jackson-Smith

   OriginalPaper Pages: 172 - 178

7. Retardation of rabbit nictitating membrane conditioning following US preexposures depends on the distribution and number of US presentations

   • Michael E. Saladin
   • William N. Ten Have
   • Robert W. Tait

   OriginalPaper Pages: 179 - 187

8. Context effects on conditioning, extinction, and reinstatement in an appetitive conditioning preparation

   • Mark E. Bouton
   • Charles A. Peck

   OriginalPaper Pages: 188 - 198

9. Stimulus blocking during compound discrimination training with pentobarbital and visual stimuli

   • Torbjörn U. C. Järbe
   • Bengt Johansson

   OriginalPaper Pages: 199 - 204

10. Differential second-order aversive conditioning using contextual stimuli

    • Fred J. Helmstetter
    • Michael S. Fanselow

    OriginalPaper Pages: 205 - 212

11. Reciprocal overshadowing in the discrimination of color-odor compounds by honeybees: Further tests of a continuity model

    • P. A. Couvillon
    • M. E. Bitterman

    OriginalPaper Pages: 213 - 222

12. Component duration effects in multiple schedules

    • Ben A. Williams

    OriginalPaper Pages: 223 - 233

13. Biological constraints revisited: A critique

    • Ernest N. Damianopoulos

    OriginalPaper Pages: 234 - 242

14. Unlike American Robins (Turdus migratorius), European Starlings (Sturnus vulgaris) do not display roost-time restlessness

    • Leonard A. Eiserer
    • Roger K. R. Thompson

    OriginalPaper Pages: 243 - 246

15. Behavioral contrast in pigeons and rats: A comparative analysis

    • James D. Dougan
    • Valeri A. Farmer-Dougan
    • Frances K. McSweeney

    OriginalPaper Pages: 247 - 255

16. Aversive conditioning of naturally produced reward and nonreward odors in rats

    • W. Robert Batsell
    • H. Wayne Ludvigson

    OriginalPaper Pages: 256 - 260

17. Cross-modality transfer effects in conditioning-enhanced neophobia in chicks (Gallus domesticus): Evidence for the separability of novelty from specific stimulus characteristics

    • Joseph J. Franchina
    • Antoinette B. Dyer

    OriginalPaper Pages: 261 - 265

18. Notices and announcements

    Announcement Pages: 266 - 267