Effect of CER on DRL responding

The effect of CER on DRL 16 was studied in four rats. All Ss showed complete CER suppression after five CER trials, together with some unconditioned post-shock suppression. This post-shock suppression showed complete recovery in all Ss after 10 days of five CER trials per day, but complete CER suppression continued throughout.     

Inducing behaviour change in adolescent delinquents

Approximately forty delinquents were offered part-time jobs of talking into a tape recorder about anything they wished. A simple reinforcement procedure was initiated whereby attendance at work became dependable and prompt within twenty-five meetings. A three-year follow-up of the first twenty employees showed a significant reduction in the frequency and severity of crime when compared to a matched-pair control group. The use of referral and “treatment” procedures was minimal.     

Quantitative relations between avoidance behavior and pituitary-adrenal cortical activity

The rate at which monkeys pressed a lever and avoided shocks was manipulated in several ways. Measurements were also made of their plasma levels of 17-hydroxycorticosteroids. The rate at which the animals pressed the lever and the frequency with which they received shocks were both implicated as determiners of the steroid levels.     

The quail, Coturnix coturnix, as a laboratory animal

The quail, Coturnix coturnix, is small, gentle, hardy, adaptable, easy to house, and economical to maintain. Wetherbee and Jacobs (1960) call it the “Drosophila of the avian laboratory,” and yet this charming bird is virtually unknown to the psychological laboratory. Our preliminary investigations show that the pecking operant is readily conditioned and that little or no deprivation is necessary to maintain behavior with food as a reinforcer. Visual and temporal discriminations were very quickly made. Our observations suggest that the social behavior of these birds might be a fruitful area for psychological study. On the basis of our somewhat limited observations, we believe that C. coturnix should prove a useful experimental animal for comparative studies, for basic research in learning, motivation, and perhaps social behavior, and for teaching the analysis of behavior in demonstrations and laboratory courses.     

Effects of chlorpromazine on appetitive and aversive components of a multiple schedule

A multiple schedule having both an appetitive and an avoidance component was maintained in two dogs to create a complex behavioral base line for observing the effects of chlorpromazine. Both soluble and “Spansule” chlorpromazine generated similar functions relating drug dose to measures of behavioral output. Although the dose ranges and the drugging procedures differed markedly for the different preparations of CPZ, the functions generated were comparable. There was no evidence that chlorpromazine had a differential depressing effect as a function of type of reinforcement. At low doses, rates of responding on the food-reinforced components increased slightly, whereas rates on the avoidance components remained relatively unchanged. At higher doses, both components showed an approximately equal depression of responding. These results are discussed with reference to some of the logical and experimental difficulties inherent in making comparisons across components of a multiple schedule and across schedules in general.     

A facilitative effect of punishment on unpunished behavior

The key pecking of two pigeons was reinforced on a variable-interval schedule of reinforcement during the presentation of each of two stimuli. In various phases of the experiment, punishment followed every response emitted in the presence of one of the stimuli. In general, when the rate of punished responding changed during the presentation of one stimulus, the rate of unpunished responding during the other stimulus changed in the opposite direction. This sort of change in rate is an example of behavioral contrast. When punishment was introduced, the rate of punished responding decreased and the rate of unpunished responding increased as functions of shock intensity. When the rate of previously punished responding increased after the termination of the shock, the rate of the always unpunished responding decreased. When the procedure correlated with a red key was changed from variable-interval reinforcement and punishment for each response to extinction and no punishment, the rate of reinforced responding during presentations of a green key decreased and then increased while the rate of the previously punished responding during red first increased and then decreased during extinction.     

On the form of learning curves

In a wide variety of learning experiments, cumulated measures of performance turn out to be a power function of practice time or number trials, typically with an exponent between 1 and 2. The effects of various conditions on the course of learning can frequently be described in terms of the two constants of the function.     

The conditioning of textual responses using “extrinsic” reinforcers

Six 4-year-old Ss were presented with a textual program consisting of 26 words arranged so the word stimuli were gradually combined into sentences and then short “stories.” Three Ss were given the No-Reinforcement condition first, and only social reinforcers were presented. They were switched to the Reinforcement condition as soon as they requested discontinuance of the activity. The other three Ss were given Reinforcement—No Reinforcement—Reinforcement treatments. The No-Reinforcement treatment in this case lasted until S requested discontinuance of the activity. The reinforcers were mixed edibles and trinkets, as well as tokens backed up by small plastic toys on a 1:24 ratio. The unit of response was the number of new texts acquired as a result of each of the 45-min experimental sessions. It was demonstrated that the program, procedure, and reinforcement conditions produced curves which are analogous to those produced in common operant-conditioning procedures. The results indicate that other operant principles may be studied in this significant area of human behavior, with important practical consequences.     

Generalization and discrimination as a function of the SD — SΔ intensity difference

Three groups of four rats were trained on an auditory-intensity discrimination for 21 days. The S^D-S^Δ intensity difference for Group I was 10 db; for Group II, 20 db; and for Group III, 30 db. Following the initial discrimination training, the animals were tested for generalization of the bar-press response to seven novel S^Δ's which were presented intermingled with the original S^D and S^Δ values. Conclusions: (1.) The amount of simple discrimination training required to obtain fairly stable differences in S^D and S^Δ responding is an inverse function of the magnitude of the stimulus difference between S^D and S^Δ. (2.) Generalization gradients obtained immediately following simple discrimination training exhibit a maximum displaced from S^D in a direction also away from S^Δ. (3.) Gradients obtained following continued exposure to the multivalued S^Δ situation show a fairly stable maximum at the S^D value. (4.) Although the gradients tend to fall off systematically on either side of the continuum as distance from S^D is increased, they decrease most rapidly on the S^Δ limb of the gradient.