ADDITIONAL‐DELAY SCHEDULES: A CONTINUUM OF TEMPORAL CONTINGENCIES BY VARYING FOOD DELAY

Pigeons performed on discrete‐trial, temporally defined schedules in which the food delay ( D ) was adjusted according to the latency of the key peck ( X ) and two schedule parameters ( t and A ). The schedule function was D = A ( t ‐ X ), where D is the experienced delay between a response and a reinforcer. The schedule parameter t is the maximum value below which the present contingencies occur. A is the additional delay to reinforcement for each second the response latency is shorter than the t value. When A = 0 s, the schedule is a continuous reinforcement schedule with immediate reinforcement. When A = 1 s, the schedule is a conjunctive fixed‐ratio 1 fixed‐time t ‐s schedule. When A approaches infinity, the schedule becomes a differential reinforcement of long latency schedule. The latencies for subjects with t = 10 s and t = 30 s were observed with the present schedules having seven values for A between 0 s and 11 s. In addition, the latencies for subjects for which t = 30 s were observed at an A value of 31 s to 41 s. As the A value increased, the latencies approached the t value for subjects for which t = 10 s. The latencies for 30‐s‐ t subjects did not approach t , even when the A value was 41 s. The latencies for 10‐s‐ t subjects at 11‐s A value were longer than those under yoked conditions having exactly the same delays/interreinforcement intervals. These results demonstrated a continuum of latency related to the schedule continuum (value of A ) at a small t value.