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1.
Three experiments, using rats, demonstrated the encoding of a food unconditioned stimulus (US) in a simple Pavlovian conditioning paradigm. In all three studies, one stimulus was used to signal the delivery of pellets and a different stimulus was used to signal the delivery of sucrose. In Experiment 1, postconditioning devaluation of one of the food USs selectively reduced the frequency of conditioned magazine-directed behavior during the stimulus trained with that US. In Experiment 2, transfer of the stimuli to instrumental responses resulted in selective depression of the response trained with a different outcome. In Experiment 3, acquisition of stimulus-outcome learning was impaired by unsignaled intertrial presentations of the same outcome but not of a different outcome. These results indicate that a detailed representation of the outcome is encoded in the normal course of Pavlovian conditioning. 相似文献
2.
A second-order autoshaping procedure was used to examine the effects of three variables on the amount of information that could be learned about the stimulus properties of a reinforcer. All three experiments paired several keylight S2s with different keylight S1s and then carried out discriminative autoshaping with those S1s. Learning about the stimulus properties of S1 was inferred from changes in the response to its paired S2 when that S1 was changed in value. The sensitivity of S2 to changes in S1 was investigated as a function of number of S2-S1 pairings (Experiment 1), partial reinforcement (Experiment 2), and temporal distance between S2 and S1 (Experiment 3). Each experiment found evidence of a selective change in responding to an S2 as a function of the treatment of its S1. However, the amount of that change was not affected by any of the three variables studied. Those results imply that, within the ranges used here, none of these variables changes the degree of learning about the stimulus properties of a reinforcer. 相似文献
3.
Ruth M. Colwill 《Learning & behavior》2001,29(2):153-164
The effect of noncontingent outcomes on an instrumental response-outcome (R-O) association was examined in four experiments using transfer tests. In each experiment, rats were first given instrumental discrimination training designed to establish different stimuli as signals (S+s) for different outcomes. Transfer responses were subjected to different treatments across the experiments and then tested with the S+s. In Experiments 1 and 2, two transfer responses were both initially trained with two contingent outcomes. Then, each transfer response was subjected either to the addition of noncontingent presentations of one of those outcomes (Experiment 1) or to the replacement of one of the contingent outcomes with noncontingent presentations of that outcome (Experiment 2). Transfer tests revealed no significant difference in the ability of an S+ to promote performance of a transfer response based on their shared association with either the contingent or the noncontingent outcome. These results suggest that a response reinforced with two outcomes remains equally well associated with both of those outcomes despite prolonged exposure to noncontingent presentations of one of those outcomes. In Experiments 3 and 4, the possibility that the noncontingent schedules of reinforcement used in Experiments 1 and 2 might be capable of establishing an association between a response and its noncontingent outcome was examined. Transfer responses were trained with one contingent outcome and a different noncontingent outcome. Performance of these transfer responses was augmented more by presentations of an S+ trained with the contingent outcome than with the noncontingent outcome. These results confirm previous reports that instrumental responses are sensitive to outcome contingencies in acquisition and that noncontingent outcome presentations do not weaken previously established R-O associations. Several explanations are considered for the failure of subsequent noncontingent presentations of an outcome to reduce the strength of its association with the instrumental response. 相似文献
4.
Two experiments examined the effects of extended training on the development of response-reinforcer associations. Rats were trained by using various food reinforcers to make multiple instrumental responses. Subsequently, those reinforcers were devalued by being paired with a toxin. The presence of response-reinforcer associations was inferred from the decrease in the likelihood of a response following devaluation of its reinforcer. Such response-reinforcer associations are known to contribute to performance after moderate amounts of training. These experiments addressed the question of whether the contribution of those associations remains constant, increases, or decreases with more extended training. Experiment 1 found that even after a response had been extensively trained with one reinforcer, the substitution of a new reinforcer produced new associations between the response and that new reinforcer. After extended training, a response continued to acquire new associations with a reinforcer, as indexed by the impact of a devaluation procedure. Experiment 2 directly compared the contribution of reinforcers used extensively and moderately with the same response. It found that devaluation of the extensively used reinforcer more effectively reduced performance of the response, suggesting that the associations formed with additional training contribute to performance of the response. These experiments indicate that the contribution of response-reinforcer associations does not decrease but, instead, continues to grow throughout the course of extended instrumental training. 相似文献
5.
In three experiments using rats, we examined the role of a discriminative stimulus (S) in governing the relation between a response (R) and an outcome (O) in an appetitive instrumental learning paradigm. In each experiment, we attempted to distinguish between a simple S-O association and a hierarchical relation in which S is associated with the R-O association. We used three variations on discriminative training procedures and three different assessment techniques-for revealing the hierarchical structure. In Experiment 1, we employed a training procedure in which S signaled a change in the R-O relation but no change in the likelihood of O. Although such an arrangement should not produce an excitatory S-O association, it nevertheless generated an S that controlled responding and transferred that control to other responses. In Experiment 2, we used a discrimination procedure in which two Ss each had the same two Rs and Os occur in their presence but each S signaled that a different R-O combination would be in effect. This design provided the opportunity for equivalent pairwise associations among S, R, and O but unique hierarchical relations. The subjects learned the hierarchical structure, as revealed by the specific depressive effect of a subsequent lithium-chloride-induced devaluation of O on responding only in the presence of the S in which that response had led to that outcome. In Experiment 3, one S signaled two different R-O outcomes. Then, two new stimuli were presented with the original S; the R-O relations were retained in the presence of one of the added stimuli but were rearranged in the presence of the other. The added S came to control less responding when it was redundant with respect to the R-O relations than when it was informative. Although all of the results were of modest size and each has an alternative interpretation, together they provide converging evidence for the hierarchical role of S in controlling an R-O association. 相似文献
6.
Three experiments demonstrated Pavlovian appetitive discrimination learning in the marine mollusc,Aplysia californica. In each experiment, subjects were exposed to two conditioned stimuli; one stimulus (CS+) was paired with food presentations and the other stimulus (CS?) was never followed by food. In Experiments 1 and 3 different chemosensory stimuli were used, and in Experiment 2 different tactile stimuli were used. For both types of conditioned stimuli, bite responses occurred significantly more often to the CS+ than to the CS?. Experiment 2 also showed thatAplysia could learn a reversal of this discrimination. Experiment 3 showed that nonreinforced presentations of CS+ resulted in a decline in the frequency of conditioned biting. The implications of these results for neurobiological analyses of learning are discussed. 相似文献
7.
This article analyzes the common educational challenges faced by curriculum developers in the UK at the turn of the 21st century
and the steps taken to address them by the Qualifications and Curriculum Authority in England and the Council for Curriculum
Examinations and Assessment in Northern Ireland. The paper explores how the solutions emerging during the three curriculum
review phases of 1998–1999 and 2005–2007 in England and 2000–2004 in Northern Ireland came about largely as a result of collegial
working between the two bodies. As well as considering steps taken to develop aims that would drive curriculum change and
a curriculum that would address the learning needs of students in the 21st century, the article also considers the lessons
learnt about managing and supporting curriculum change. Developments in England and Northern Ireland serve to illustrate that
an effective curriculum needs to: articulate clearly the key aims that will shape and drive it; be sufficiently visionary
and flexible to allow teachers to respond to the needs of students now and in the future; and provide on-going support to
help embed and sustain change. The three are inter-related and successful curriculum development involves considering them
together.
Ian Colwill is a freelance educational consultant. Until his recent retirement, he was a member of the executive of the Qualifications and Curriculum Authority in England with responsibility for curriculum development. He began his career teaching history in a secondary school in inner London before becoming an advisory history teacher for the Inner London Education Authority. He has since held senior posts in a succession of bodies advising the government on curriculum and assessment development with responsibility for developing and revising the national curriculum and producing a wide range of support materials. Carmel Gallagher is currently a Visiting Senior Research Fellow at the UNESCO Centre, University of Ulster. Until recently, she was the manager in charge of Curriculum and Assessment Development at the Northern Ireland Council for Curriculum, Examinations and Assessment (CCEA), a post from which she has been seconded. She began her career teaching history in a large comprehensive school in West Belfast during some of the worst years of the Northern Ireland Troubles. She was seconded from this post to a number of curriculum development projects before she became the officer in charge of the history curriculum at the newly formed Northern Ireland Curriculum Council (NICC). Soon after this organisation merged with the Northern Ireland Secondary Examinations Council to form CCEA, she took over responsibility for the curriculum review process from 1996–2006, the production of a wide range of support materials and the development of an implementation strategy. 相似文献
| Carmel GallagherEmail: |
Ian Colwill is a freelance educational consultant. Until his recent retirement, he was a member of the executive of the Qualifications and Curriculum Authority in England with responsibility for curriculum development. He began his career teaching history in a secondary school in inner London before becoming an advisory history teacher for the Inner London Education Authority. He has since held senior posts in a succession of bodies advising the government on curriculum and assessment development with responsibility for developing and revising the national curriculum and producing a wide range of support materials. Carmel Gallagher is currently a Visiting Senior Research Fellow at the UNESCO Centre, University of Ulster. Until recently, she was the manager in charge of Curriculum and Assessment Development at the Northern Ireland Council for Curriculum, Examinations and Assessment (CCEA), a post from which she has been seconded. She began her career teaching history in a large comprehensive school in West Belfast during some of the worst years of the Northern Ireland Troubles. She was seconded from this post to a number of curriculum development projects before she became the officer in charge of the history curriculum at the newly formed Northern Ireland Curriculum Council (NICC). Soon after this organisation merged with the Northern Ireland Secondary Examinations Council to form CCEA, she took over responsibility for the curriculum review process from 1996–2006, the production of a wide range of support materials and the development of an implementation strategy. 相似文献
8.
In four experiments, we investigated encoding of the reinforcer in instrumental learning. We contrasted the view that the reinforcer is encoded as a consequence of the response with the position that the expectation of the reinforcer serves as an antecedent stimulus for the response. In all four experiments, a response was followed by one reinforcer in the presence of a stimulus known to elicit an expectation of a different reinforcer. In Experiments 1 and 2, we found that devaluing the consequent reinforcer reduced performance of the response more than did devaluing the expected reinforcer. In Experiment 3, we found no evidence at all for a detrimental effect of devaluing the expected reinforcer. Experiment 4 showed that a stimulus associated with a reinforcer will preferentially promote a response that has the same-consequent reinforcer rather than the same-antecedent reinforcer. These results provide further support for the view that response-reinforcer associations are the crucial product in instrumental learning situations. 相似文献
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10.
To meet the demands of industry, the skill base necessary for information systems personnel has broadened in scope to encompass not only technical abilities but competence in team work, communication, and creativity, and an understanding of business functions. The traditional approach to information systems curricula, however, may not fully serve to address these areas in student development. This paper proposes the use of a capstone information systems course as a part of an information systems education to develop students’ abilities and skills needed in the integrative information systems/technology and business areas. It is argued that a properly designed and taught capstone course offers curriculum flexibility and can satisfy the requirements of stimulating the creative mind to integrate various interrelated concepts, and acquisition of practical knowledge. 相似文献