Date of Graduation


Document Type


Degree Type



Eberly College of Arts and Sciences



Committee Chair

Kennon A. Lattal.


The resurgence of temporal patterns of key pecking by pigeons was studied in two experiments. In Experiment 1, positively accelerated and linear patterns of responding were established under a discrete-trial multiple fixed-interval (FI) variable-interval (VI) schedule. Subsequently, responding on a different key produced reinforcers according to a VI schedule. When extinction was in effect, resurgence of previously established temporal patterns was observed for each pigeon. That is, positively accelerated and linear patterns recurred in the presence of the stimuli previously correlated with the FI and VI components of the multiple schedule, respectively---suggesting that these temporal patterns, although not directly reinforced, functioned as behavioral units. In Experiment 2, resurgence was assessed after positively accelerated patterns of responding were directly reinforced. Responding was reinforced only if the patterns approximated a predetermined temporal distribution of responses. Resurgence of previously reinforced patterns occurred for each pigeon and for 2 of 3 pigeons during a replication of the procedure. Although variability in patterns increased during the resurgence phases in Experiment 2, those patterns that occurred most frequently when reinforcement was in effect occurred at a higher relative frequency during extinction. These results (a) demonstrate the resurgence of temporally defined complex operants, (b) replicate and extend previous findings on resurgence of spatially defined operants, and (c) are discussed as they contribute to understanding the selection and recurrence of more complex behavioral units.