The Temporal Distribution of Short-Duration Keypecks in Variable-Interval Schedules of Reinforcement

An experiment was conducted in order to determine the duration of pigeons\u27 keypecks during three separate variable-interval schedules of reinforcement. Pigeons were exposed to variable interval (VI) 30 sec, VI 60 sec and VI 120 sec schedules of reinforcement for twenty sessions each. Response durations were analyzed in terms of VI schedule , location in time during the inter-reinforcement interval and any pattern of short and long duration pecks. Mean duration of response was reliably different for three out of four birds for VI 30 sec and VI 120 sec schedules of reinforcement. The VI 30 sec schedules produced longer durations. Results for the VI 60 sec condition were equivocal. Mean duration of response was constant throughout the VI interval showing no change in response duration over time. No pattern of long and short pecks was detected. Results were interpreted as confirming the existence of a range of response durations during VI schedules of reinforcement and suggesting that duration of response varies with VI schedule changes