Rats in a shuttle box were reinforced by shock termination after delays of 0, 1, 2, 4, 8, or 16 sec. All Ss received 100 training trials and Ss in Groups 0, 1, and 4 received an additional 30 test trials on which shock termination was delayed for 20 sec. During training and testing, escape latency, and Ss' location in the compartment at the moment of shock termination were recorded. Number of trials required to reach criterion was directly related to length of delay. The differences between asymptotic response levels were small and, with the exception of Group 16, nonsignificant. Ss in Groups 2, 4, and 8 showed a significant increase in location consistency during training. During resting Groups 0 and 1 showed marked decrements in performance while Group 4 showed no increase in escape latency. Group 4 also showed significantly higher location consistency than Groups 0 and 1. These findings were discussed in relation to Spence's theories of delay of reinforcement and extinction.
Delay of reinforcement and delay shifts in dyadic communication