Delay Patterns, Delay-Box Confinement, and Instrumental Performance
72 rats were trained in a runway for 9 days. Group D1 was delayed for 20 sec. on the first 3 days, D2 on the second 3 days, and D3 on the last 3. All other trials were rewarded immediately. During 5 days of extinction half of Ss had 20-sec. delay-box confinement on all trials; the other Ss had no confinement. Delays in training produced sudden, pronounced changes in behavior. on the average, Ss ran faster in both training and extinction, the earlier delay was introduced in training. Running speed in extinction varied inversely with the duration of confinement in extinction. Shifts to increased delay from training to extinction produced faster extinction; shifts to decreased delay led to slower extinction in comparison with relevant unchanged groups.