Abstract
Four experiments are reported in which the amount of CRF training prior to extinction is examined as it effects transient changes in response frequency and duration immediately following extinction onset. The first two experiments, using albino rats as subjects and water reinforcement, revealed a reliable relationship between length of time on CRF and the tendency to increase response frequency, duration, and the variability of response frequency and duration. Two comparative experiments were conducted using 53-to-69-month old children as subjects, and recorded music as reinforcement. The results of the first child study failed to conform with those obtained in the rat experiments. However, manipulation of the reinforcer in a subsequent study reproduced the rat extinction effect. Despite the differences in the rat and child experiments, the qualitative similarity of the results of the four studies suggests a basic underlying comparability of the relationship between the amount of training and transient changes in response frequency.