Effects of reinforcement frequency and extinction- component duration within a mixed schedule of reinforcement on observing responses in rats

Abstract

The present experiment examined the effects of varying reinforcement frequency and extinction-component duration on observing responses in rats. Pressing one lever was reinforced with food pellets on a mixed random-interval t s extinction schedule. Pressing a second lever produced 5-s stimuli correlated with each of the schedule components. Holding constant reinforcement-component duration at 30 s, three rats were each exposed to a different extinction-component duration of either 15, 30, 60 or 120 s. The random-interval schedule, present in the reinforcement component, was either 5, 10, 20, 40, 80 or 160 s across successive blocks of 30 sessions. Observing-response rate was an inverted U function of extinction-component duration. Decreasing reinforcement frequency resulted in an inverted U function of observing responses for extinction-component durations of either 15, 30 or 60 s and in a decreasing function under 120 s. The rate of observing responses was higher under extinction than during the reinforcement component. It was found that as the number of pairings of reinforcement-component stimuli with reinforcement delivery increased, observing responses during extinction also increased. Rather than supporting an interpretation of these data in terms of Information Theory, the present results suggest an explanation in terms of behavior-analytic knowledge.