Runway performance in rats as a function of goal-box placements and goal-event sequence.

Abstract

The effects of intertrial reinforcement (ITR), partial delay (PD) of reinforcement, intertrial nonreinforcement (ITN), and the sequence of goal events per se on acquisition and extinction performance were investigated in a series of three runway experiments with rats. With limited training, ITRs following nonreinforced (N) trials attenuated the typically obtained partial reinforcement extinction effect (FREE), whereas when training was extended this procedure failed to eliminate the FREE. The ITRs when administered following N trials were found to facilitate acquisition performance. The ITNs were found to enhance resistance to extinction (Rn) after limited training, but had no effect on Rn with extended training. The PD of reinforcement under both conditions enhanced Rn.

Frustration considerations of the small-trials partial reinforcement effect: Experience with nonreward and intertrial reinforcement.

“…McCain (1966, Exp. IV) replicated this finding and further showed that reduced persistence of responding during extinction did not occur when ITRs were given only following R trials. Similar findings have recently been reported by Homzie, Rudy, and Carter (1970).…”

Effect of nonrewarded and partially rewarded placements on resistance to extinction in the rat.

“…If it is assumed that the reinstatement of S N from placements on the subsequent long-run trial becomes weaker as training progresses, a number of additional findings may be interpreted. It would be expected, for example, that a group which receives nonrewarded placements intermixed with consistently rewarded long runs would be more resistant to extinction early in training than later in training, as has been found by, for example, Homzie et al (1970). Also, it would be expected that if Experiment 1 had employed a limited number of training trials, Group N-Rshort-run and Group N-Rlong-run would be about equal in resistance to extinction and more resistant to extinction than Group R, as has been found by Homzie et al (1970) employing only six placements.…”

Runway performance in rats as determined by the predictive value of intertrial reinforcements.

“…Working within the context of the aftereffects hypothesis, Capaldi and his colleagues (e.g., Capaldi, Hart, & Stanley, 1963) administered intertrial reinforcements (ITRs) after nonreinforced (N) trials which preceded reinforced (R) trials and eliminated the partial reinforcement extinction effect (FREE). There is evidence (e.g., Homzie, Rudy, & Carter, 1970) that the ITR procedure, while effectively eliminating increased resistance to extinction (Rn) after a few baited goal-box placements, fails to eliminate the FREE after many placements. It has been suggested (e.g., Black & Spence, 1965) that with extended training, generalization between ITR events and runway trials is reduced such that the placement procedure is ineffective in influencing the extinction performance of the runway response.…”