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PubMed1982

Concept learning by retarded children: a comparison of three discrimination learning procedures.

The effectiveness of stimulus delay and stimulus fading procedures was compared with differential reinforcement only in training developmentally delayed children on a concept learning task. Twenty-four children were randomly assigned to one of the three treatment conditions. All three experimental conditions contained five discrimination programmes, each designed to teach the child to discriminate one pair of exemplars from the target concepts bottle and jar. Following successful completion of one training programme, a concept acquisition probe was administered to determine whether the target concepts had been engendered. Alternate presentations of successively different training programmes and concept acquisition probes were continued until the subject passed the probe, failed to complete a training programme, or completed all five training programmes. Five 'stimulus fading' subjects, three 'stimulus delay' subjects, and four 'reinforcement only' subjects learned the concepts. All children who learned to discriminate one pair of exemplars displayed conceptual behaviour after training on two or fewer pairs of exemplars. It was suggested that the absence of pronounced differences between conditions may have been due to the complexity of the task or the type of prompts employed.

Child, Preschool↗
PubMed1963

Aversive aspects of a schedule of positive reinforcement.

Six male White Carneaux pigeons were trained to peck at one of two keys to obtain food on several fixed-ratio schedules of reinforcement. Concurrently, the first response on a second key could, I-change the conditions of visual stimulation and remove the food reinforcement contingency, II-change the conditions of stimulation and have no effect upon the reinforcement contingency, or III-do nothing. The second response on the stimulus change key always restored baseline conditions. When second-key responses produced a stimulus change, the number of such responses was a function of the ratio value on the first key. Typically, second-key responses occurred before the start of fixed-ratio runs. The duration of stimulus change periods was an exponential function of the number of responses required for reinforcement when the possibility for reinforcement was not disturbed by periods of stimulus change (Condition II).

Animals↗
PubMed1998

Do parakeets exhibit derived stimulus control? Some thoughts on experimental control procedures.

Breaking new ground in the study of emergent stimulus control in nonverbal subjects may require innovation in procedures. A recent study of parakeets is exemplary. This study used intricate procedures for maintaining test-trial performance without differential reinforcement of the target emergent performance. Also, it used successive simple discrimination procedures, which are rare in such studies. Given the importance of these innovations and the outcomes that they produced, we suggest additional control procedures that would rule out the possibility of adventitious reinforcement of the test-trial performances.

Animals↗
PubMed1981

Impairment of instrumental learning in rats by glutamic acid diethyl ester.

Glutamic acid diethyl ester (GDEE), a putative antagonist of glutamate-induced neuronal excitations, was administered prior to an instrumental conditioning task motivated by food reinforcement. A profound impairment of learning was produced in animals receiving 240 or 480 mg/kg of GDEE. Performance was not impaired by GDEE in rats that had previously learned the task. These findings support suggestions that central excitatory processes play an important role in learning phenomena, in particular when these learning phenomena involve acquisition of new behavioral patterns.

Animals↗
PubMed1979

Intrahypothalamic microinjections of noradrenaline with and without induction of the alimentary drive as a reward in a T maze learning in rats.

Noradrenaline injected into the perifornical region of the anterior part of the lateral hypothalamus in rats can serve as a reinforcement in a T maze learning, whether it induces the activation of the alimentary drive or not. It follows that the main role of noradrenaline in this brain area consists not so much in induction of the alimentary drive as in activation of the very process which is essential for the reinforcement. It is claimed that intrahypothalamic microinjections of noradrenaline evoke pleasurable states which constitute a virtual reinforcement of motivated behavior.

Animals↗
PubMed2000

NMDA receptor antagonism in the basolateral amygdala blocks enhancement of inhibitory avoidance learning in previously trained rats.

Extensive evidence suggests that N-methyl-D-aspartate (NMDA) glutamate receptor channels in the amygdala are involved in fear-motivated learning, and infusion of NMDA receptor antagonists into the amygdala blocks memory of fear-motivated tasks. Recent studies have shown that previous training can prevent the amnestic effects of NMDA receptor antagonists on spatial learning. In the present study, we evaluated whether infusion of the NMDA antagonist D,L-2-amino-5-phosphonopentanoic acid (AP5) into the basolateral nucleus of the amygdala (BLA) impairs reinforcement of inhibitory avoidance learning in rats given previous training. Adult male Wistar rats (220-310 g) were bilaterally implanted under thionembutal anesthesia (30 mg/kg, i.p.) with 9.0-mm guide cannulae aimed 1.0 mm above the BLA. Infusion of AP5 (5.0 microg) 10 min prior to training in a step-down inhibitory avoidance task (0.4 mA footshock) blocked retention measured 24 h after training. When infused 10 min prior to a second training session in animals given previous training (0.2 mA footshock), AP5 blocked the enhancement of retention induced by the second training. Control experiments showed that the effects were not due to alterations in motor activity or footshock sensitivity. The results suggest that NMDA receptors in the basolateral amygdala are involved in both formation of memory for inhibitory avoidance and enhancement of retention in rats given previous training.

2-Amino-5-phosphonovalerate↗
PubMed1979

Contrast, component duration, and the following schedule of reinforcement.

Experiment 1 investigated component duration in a four-component multiple schedule designed to separate the effects of the preceding schedule of reinforcement from those of the following schedule of reinforcement. The preceding schedule in the preceding component had no consistent effect regardless of component duration. The following schedule was a powerful determinant of behavior, however, with higher response rates resulting from a following period of extinction. Moreover, the effect of the following schedule was greater with short component durations, which strongly suggests that component-duration effects previously found with multiple schedules are due generally to variation in the degree of control by the following schedule. Experiments 2--4 investigated the basis of the effects of the following schedule. In some situations differential responding in the following component was the controlling variable, but in others it was differential reinforcement in the following component. The results are consistent with the view that response rate during a stimulus is inversely related to the "value" of the following component, where the calculation of value must include both primary and conditioned reinforcement.

Animals↗
PubMed1975

Aversive effects and retention impairment induced by acetoxycycloheximide in an instrumental task.

AXM, when subcutaneously injected during the first 3 min following the acquisition of a nondiscriminative instrumental learning task, induced an aversion for the food reinforcement which had been associated with the training situation and with the pharmacological treatment. The high number of nonreinforced responses preceding the first reinforced response(RR) that animals performed when tested 6 days after AXM treatment, was not due to forgetting of the lever significance, but to this aversion. Animals treated with AXM showed low levels of lever pressing response and long latencies for their first RR; this deficit did not seem only to be due to food reinforcement aversion; it disappeared, as well as food aversion, when food reinforcement which had been associated with the learning situation and to treatment, was added to the daily feeding regimen during treatment-test interval. It has been shown, moreover, that more than 90 percent of cerebral protein synthesis was inhibited during the 5 hr following subcutaneous AXM injection. These findings are interpreted as an indication that AXM does not affect memory consolidation of a non discriminative instrumental learning.

Animals↗
PubMed1974

Elaboration of conditioned alimentary reflexes having different probabilities of reinforcement in rats with hippocampal lesions.

A motor alimentary conditioned reflex was elaborated in hippocampectomized and intact albino rats. Food reinforcement followed 100 percent, 50 percent, 33 percent or 25 percent of conditional stimulus presentations (click from a rotating food box). No differences were found in the rate of conditioned alimentary reflex elaboration between the hippocampectomized and control rats at 100 percent and 50 percent reinforcement, although the time-courses of formation of the conditioned reflex connection differed substantially. With low reinforcement probabilities (33 percent and 25 percent) the operated rats, unlike the intact ones, exhibited no adequate responses throughout the 10 experimental days. The results obtained corroborate an earlier suggestion that the hippocampus is involved in the organization of behavior the reinforcement probability of which is unknown or relatively low.

Acoustic Stimulation↗
PubMed2002

[Modes of reinforcement and gender and culture of experimenter and subject: effects of "alien" and external reinforcement for Japanese and American men and women].

In this study, we examined external and "alien" reinforcement (ER and AR. respectively) as a factor in social learning, and studied the combined effects of culture and reinforcement mode. A female (Experiment 1) and a male (Experiment 2) experimenters conducted experimental sessions. Both men and women, who grew up in the same culture as the experimenter, participated and performed the experimental task. A three-way interaction effect of experimenter gender, culture, and reinforcement mode was found on task performance. And the effect was more pronounced for a Japanese experimenter. A female and a male experimenters conducted Experiments 3 and 4, respectively; however participants this time were men and women who grew up in different cultures than the experimenter. Results indicated that the pattern of the subject gender and reinforcement mode interaction effect, when the experimenter was Japanese with American subjects, was exactly opposite to that when the experimenter was American. These experiments showed that AR was as effective for social learning as ER, and that the cultural backgrounds of experimenter and subject influenced AR and ER effectiveness.

Adult↗
PubMed2001

Contingent reinforcement or defending the self? A review of evolving models of aggression in people with mild learning disabilities.

This paper examines the changing approaches to working with people with a moderate to mild learning disability, who are frequently aggressive. Long-held assumptions about the lack of inter-personal understanding and impulsiveness continue to play a central role in clinical assessment and intervention for this group. Yet, there is a lack of controlled studies indicating the influence of such factors in frequent aggression. The dominant behavioural tradition has long encouraged such assumptions, but has focused on people with more severe disabilities where such assumptions are arguably more appropriate. The current review of the literature shows a clear evolution away from a strict behavioural approach towards cognitive-behavioural therapy (CBT) approaches that take account of the heterogeneous psychosocial causes of aggression. We find support for CBT in the child-development literature, which examines inter-personal difficulties from an information-processing perspective. Finally, we argue that much of the literature implicitly utilizes the concept of self, and we suggest that this should be made explicit in a reformulated theory of the 'person', incorporating the self concept and embedding individual cognitive processes and behaviour in a social context.

Aggression↗