FURTHER EXPERIMENTS ON PROBABILITY‐MATCHING IN THE PIGEON¹

Abstract

In a discrete-trials, two-key choice situation, probability-learning by pigeons was studied under a variety of training conditions. Matching was found in simultaneous and in successive problems, but a spatial problem produced only maximizing. In the simultaneous problem, noncorrection produced maximizing, while correction produced matching. Guidance produced maximizing when the animals were required to earn each opportunity for choice by pecking a center key on FR-5, but matching when the center key was not used. In a discrete-trials one-key situation, with latency as the measure, frequency and probability of reinforcement were varied independently. Differences in probability produced differences in latency of response, but differences in frequency did not.

Further experiments on probability learning in goldfish

“…Bullock, & Bitterman, 1964); with unlimited correction, visual matching occurs in pigeons whether or not a CK is used, but with guidance (a procedure which controls the distribution of reinforcement without permitting repetitive errors), visual matching occurs only when a CK is not used. The failure of goldfish to show spatial matching under circumstances in which they show visual matching also is in accord with previous results for pigeons (Bullock & Bitterman, 1962;Graf et al 1964), as well as for painted turtles (Kirk & Bitterman, 1965) and for decorticated rats (Gonzalez, Roberts, & Bitterman, 1964l, in none of which spatial matching has been found.…”

PROBABILISTICALLY REINFORCED CHOICE BEHAVIOR IN PIGEONS1

“…In fact, the mean probabilities, .85 and .13, were about midway between the correspond- Further assume that unreinforced pecks on a key reduce the probability of choices of that (Graf et al, 1964) that "'the probability that the pigeon will choose a given alternative on any trial is independent of which of the two has been reinforced on the preceding trial. EXPERIMENT II Experiment II, and Exp III and IV, attempted to relate the maximizing tendency in probability learning experiments to the matching in concurrent variable interval experiments.…”

“…Graf, Bullock, and Bitterman (1964) proximated the relative frequency with which that response was reinforced. These two experiments employed either a successive or a simultaneous visual discrimination, a center key and a correction procedure.…”

“…This principle, "momentary maximizing", states that pigeons tend to choose the alternative that momentarily has the higher probability of reinforcement. Graf, Bullock, and Bitterman (1964) performed several probability learning experiments, two of which produced choice proportions that most closely approximated matching for the greatest number of trials; that is, the relative frequency of a choice response ap-'This paper is based on a thesis submitted to the Department of Psychology, Brown University, in partial fulfillment of the requirements for the degree of Doctor of Philosophy. The research was partially supported by USPHS Grant MH-02456 (D.S.…”

“…These two experiments employed either a successive or a simultaneous visual discrimination, a center key and a correction procedure. Other visual problems as well as non-visual problems lead to maximizing (Bullock and Bitterman, 1962;Graf et al, 1964). In these experiments, maximizing was said to occur when the bird almost always chose the more frequently reinforced alternative.…”