Rats were trained on a position discrimination. The experimental design involved simultaneously manipulating per cent and magnitude reward given for the correct response. Learning-rate was found to be a negatively accelerated growth function of reward magnitude for both of the reward schedules used. The results are interpreted as support for the treatment of reward magnitude as a special case of reinforcement probability. ProblemIn a previous study (Clayton, in press) three groups of rats received either 1, 2, or 4 pellets for the correct position response in a T-maze and no reward for an error. Analysis of the resulting performance suggested the following relationship between learning-rate and reward magnitude:where J ~ is the learning-rate parameter associated with r reward pellets. Equation (1) says, generally, that J r is a negatively accelerated growth function of J l' where M is a parameter effecting the growth-rate and asymptote of the curve.The present study was stimulated by an assumption regarding reward magnitude made recently by Estes & Suppes (1959). Following a Guthrian treatment of reward magnitude and distinguishing between reward and reinforcement, Estes & Suppes have suggested reward magnitude is but a special case of rei n for c e men t pro b a b i 1 i t Y in that an increase in magnitude merely increases the probability of the reinforcing event. Within this framework Equation (1) may be conceived as the relationship between learning-rate and reinforcement probability. However, a second variable affecting reinforcement probability should be reward probability, or reward schedule. In the previous study the correct response was always rewarded. The present study sought to determine the effect on the relationship between learning-rate and reward magnitude when the correct response was sometimes nonrewarded. The hypothesis tested was that if Equation (1) relates learning-rate to reinforcement probability, it should hold (with possible changes in M) regardless of whether the correct response was always rewarded.A second purpose of this study was to provide an independent check on Equation (1) with different reward magnitudes to make certain the obtained function is not specific to the particular amounts used previously. For these reasons reward magnitude was factorially manipu-
Thirty-two albino rats were given runway training with either large or small reward. When running speeds stabilized, extinction began with half the Ss in each reward group receiving shock in the unbaited goal box. As in previous studies, the large-reward groups extinguished more rapidly than the small-reward groups and the shocked Ss more rapidly than the non-shocked. However, no significant interaction was found between acquisition reward magnitude and extinction shock treatment. The results were interpreted in terms of the hypothesized mediating emotional response produced by both non-reward and shock.IN TRADITIONAL STUDIES of conflict behaviour rats are trained to traverse a runway for food reward and then given electric shock for making the instrumental response. Despite some procedural similarities little is known about the concordance of conflict behaviour and behaviour elicited by simple extinction (non-reward without shock), partly because in conflict experiments post-acquisition variables are typically manipulated, whereas in extinction studies the emphasis has been on acquisition variables. At least one study, however, has suggested that the similarities between conflict and extinction may be more than procedural. Karsh (1962) has shown that overlearning increases the effectiveness of punishment, a finding which concurs with the discovery in a number of recent studies that runway extinction is facilitated by overlearning (e.g., Ison, 1962;North & Stimmel, 1960; Siegel & Wagner, 1963) at least if reward magnitude is large (Theios & Brelsford, 1964).The significance of comparing non-reward and shock comes from theoretical positions which state that the decremental effect produced by each is mediated by an emotional response. Indeed, Wagner (1966) has made the parsimonious suggestion that after acquisition the same emotional state occurs regardless of whether it is evoked by non-reward or punishment. A reasonable question, therefore, is whether acquisition
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.