Date of Graduation


Document Type


Degree Type



Eberly College of Arts and Sciences



Committee Chair

Kennon A Lattal

Committee Co-Chair

Melissa D Blank

Committee Member

Gregory A Lieving

Committee Member

Michael Perone

Committee Member

Claire C St Peter


Pausing, like other operants, is affected by the schedule of reinforcement for alternative responses and the antecedent discriminative stimuli that set the occasion for it to be reinforced. The effects of both of these variables on pausing were further investigated in three experiments in which key pecking by pigeons was reinforced concurrently according to, respectively, a variable-interval schedule, a differential-reinforcement-of-low-rate schedule, and a fixed-ratio schedule. The antecedent discriminative stimulus control of pausing was investigated by comparing unsignaled, briefly signaled, and fully signaled pausing contingencies in each experiment. Pigeons' time allocation to pausing in both full-and brief- signal conditions with each key-peck reinforcement schedule was lower than unsignaled-baseline and control conditions, demonstrating discriminative control of pausing. Although there were no systematic differences between the brief- and full-signal conditions, how pauses of the required duration were assimilated depended on the schedule of reinforcement for pecking. The current experiments replicated prior findings with a variable-interval schedule, and extended them by showing pauses were assimilated in those pauses already maintained under a differential-reinforcement-of-low-rate schedule in Experiment 2, and into the postreinforcement pause under a fixed-ratio schedule in Experiment 3. Together, these results demonstrate the antecedent and consequent control of pausing under several schedules of reinforcement for pecking, under which characteristically different peck-pause interactions emerge.