Effects of percentage reinforcement on choice in a concurrent chain schedule

Abstract

The effects of random reinforcement omissions (percentage reinforcement) on choice behavior was studied with three pigeons trained on a two-link concurrent chain schedule. A terminal-link VI schedule on one key always produced primary reinforcement; a terminal-link VI-percentage reinforcement schedule on the other key produced with equal probability either reinforcement or blackout. Relative response rates in the choice links matched the relative rates of reinforcement associated with the terminal-link schedules when these were VI 30 sec vs VI 30 sec (50%); VI 1 min vs VI 30 sec (50%); and VI 30 sec vs VI 30 sec (baseline). These results suggest that percentage reinforcement affects choice solely through its effect on rate of primary reinforcement.