Abstract
Four homing pigeons were trained to peck a response key to obtain food on several random-ratio and variable-interval schedules. A peck on another key(timeout key) produced a 20-second timeout period accompanying a visual stimulus change. As the variable-interval schedule was increased logarithmically through five values from 60 to 960 sec, frequency of timeout responses increased monotonicaly in two pigeons. In random-ratio schedule, no bird showed systematic change in the frequency of timeout responses when the schedule value was increased in successive stages from 50 to 300. No bitonic relationship was obtained between the schedule value and the frequency of timeout responses. The timeout responses during both schedules were found to be distributed throughout the inter reinforcement interval. The results suggest that the interpretation of timeout behavior in terms of schedule-induced or adjunctive behavior is open to considerable question.
