摘要:

Two experiments studied the conditions of stimulus control necessary for the generalization of relational matching to sample. Matching required the selection of comparison shapes rotated 90° clockwise from the orientation of the corresponding sample. In Experiment 1, five children were taught to: (a) code the orientations of samples, (b) transform sample codings to account for the 90° rotation, and (c) repeat the transformed sample coding response to a comparison. High levels of generalization occurred with a set of novel stimuli for which stable sample‐coding responses were initially available. In another novel set, where stable sample‐coding responses were not initially available, low levels of generalized matching were recorded. Matching performance improved after stable coding responses were trained. In Experiment 2, two children and three adults were trained in a form of the matching task that produced poor generalization despite the presence of stable sample‐coding responses. Retraining to modify the stimulus control exerted by these coding responses produced an immediate improvement in generalized matching to sample. Results suggest that the generalization of matching is dependent on the structure of stimulus control that the component responses exert on eac

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-1

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Reinforcement of effortful performance in a given academic task has been found to increase the subsequent performance of other academic tasks. The learned‐effort hypothesis assumes that individuals learn which dimensions of task performance are correlated with reinforcement of high effort, and generalize across tasks. Therefore, reinforcement of increased effort in a given dimension of one task should result in greater generalized effort in the same dimension of transfer performance than in another dimension. In accord with this view, preadolescent learning‐disabled students who Received points for high reading accuracy subsequently produced more accurate drawings and stories than did students whose points had been based upon high reading speed or upon mere completion of the reading task. Students who Received points for high reading speed subsequently constructed stories more quickly than did children whose points had been based upon high reading accuracy or upon reading‐task completion. Consistent with the more explicit and frequent feedback for accuracy than for speed in most academic tasks, generalized accuracy was much more durable than generalized

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-19

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Performances of three rhesus monkeys were reinforced by the oral delivery of pentobarbital and studied as functions of fixed‐ratio size and drug concentration. Pentobarbital solutions and water were concurrently available on identical reinforcement schedules from separate liquid‐delivery systems during 3‐hour sessions. Under a fixed‐ratio 16 schedule of drug availability, a descending series of drug concentrations was tested (4, 2, 1, 0.5, 0.25, 0.125, and 0.0625 mg/ml, followed by a retest at 4 mg/ml). Partial concentration series beginning with the highest concentration were repeated with fixed‐ratios of 32 and 64, with a fixed‐ratio 128 for two monkeys, and with fixed‐ratio 256 for one. At each fixed‐ratio value, response rate and number of drug deliveries were inverted U‐shaped functions of pentobarbital concentration. Drug intake (mg/kg/session) increased directly with drug concentration. As the fixed‐ratio size was increased, the number of liquid deliveries decreased. For each drug concentration, when the numbers of drug deliveries at fixed‐ratios of 32, 64, and 128 responses were plotted as percentages of those obtained at fixed‐ratio 16, the following orderly relationship emerged: the higher the drug concentration, the less that drug deliveries were decreased by increases in fixed‐ratio size. This relationship indicates an increase in reinforcing efficacy with increases in pe

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-37

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Pigeons, trained to discriminate phencyclidine from saline under a procedure requiring the bird to track the location of a color, Received cumulative doses of phencyclidine, pentobarbital, ord‐amphetamine with a variety of schedules of reinforcement in effect (across phases). When the same second‐order schedules were used to reinforce responding after either saline or phencyclidine administration, stimulus control by phencyclidine did not depend on the schedule parameter. When different second‐order schedules were used that biased responding toward the phencyclidine‐correlated key color, pigeons responded on the phencyclidine‐correlated key at lower doses of phencyclidine and pentobarbital than when the second‐order schedule biased responding toward the saline key color. A similar but less marked effect was obtained withd‐amphetamine. Attempts to produce bias by changing reinforcement magnitude (duration of food availability) were less successful. A signal‐detection analysis of dose‐effect curves for phencyclidine under two of the second‐order schedules employed suggested that at low doses of phencyclidine, response bias is a major determinant of responding. As doses were increased, position preferences occurred and response bias decreased; at higher doses both response bias and position preference decreased and discriminability increased. With low doses of pentobarbital, responding again was biased but increasing doses produced position preference with only small increases in discriminability. At low doses ofd‐amphetamine responding also was biased, but bias did not decrease consistently with dose nor did discriminability increase. These experiments suggest that the schedule of reinforcement can be used to bias responding toward or away from making the drug‐correlated response in drug discrimination experiments, and that signal‐detection analysis and analysis of responding at a position can be used to separate the discriminability of the drug state from other effects

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-51

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Five rats were submitted to a signaled free‐operant avoidance contingency. Throughout the experiment, shock intensity was varied from 0.1 to 8.0 mA, with shock duration constant at 200 milleseconds. Results indicate: (a) an all‐or‐none effect of shock intensity on response and shock rates, on percentage of shocks avoided, and on frequency of occurrence of responding during the preshock stimulus; and (b) no systematic effect of shock intensity on stimulus control, measured either by the percentage of stimulus presentations accompanied by a response or by the percentage of responses that occurred during those preshock stimuli. Such results indicate that for each subject there is a minimum shock intensity necessary to establish and maintain avoidance responding; intensities higher than this minimum value have little or no effect on responding (with an upper limit for those strong intensities with a general disruptive effect on beha

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-67

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Previous research has shown that unsignaled shock may accelerate positively reinforced operant responding if each shock signals a subsequent shock‐free period. In order to explore the boundary conditions of this effect, two experiments were performed. In Experiment 1, pairs of unsignaled shocks separated by 15, 30, 60, or 120 seconds resulted in suppressed responding during the briefest intershock interval, and in accelerated responding during the longer intervals. When the second shock in each pair signaled a shock‐free period of at least 3 minutes, accelerated responding also followed offset of the second shock in all but the 30‐second condition. In Experiment 2, the addition of a conditioned stimulus prior to each pair of shocks restored baseline responding, and eliminated accelerative control following the second shock only under the briefest intershock interval. The results are discussed in terms of the similarity between autocontingencies (shock/no‐shock relations; Davis, Memmott,&Hurwitz, 1975) and recent modifications of the feature‐positive procedure (e.g., Reberg&Memmott, 1979), which stress stimulus control by shock/no‐shock re

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-75

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

In two discrete‐trial delayed‐detection experiments, six pigeons were trained on dependent concurrent variable‐interval schedules. Pecking a red side key was reinforced when the brighter of two white lights (S1) had been presented on the center key, and pecking a green side key was reinforced when the duller of two white lights (S2) had been presented on the center key. Incorrect responses were red side‐key pecks following S2presentations and green side‐key pecks following S1presentations; these resulted in three‐second blackouts. In Experiment 1, the time between presentation of S1or S2on the center key and the onset of the red and green side keys was varied nonsystematically from 0.06 seconds to 19.69 seconds across experimental conditions. Stimulus discriminability decreased as the stimulus‐choice delay increased. A rectangular‐hyperbolic function better described this decrease in discriminability over time than did a negative‐exponential function. In Experiment 2, at each of three stimulus‐choice delays (0.06, 3.85, and 10.36 seconds), relative reinforcer frequency for correct responses to the red and green side keys was varied by changing the values of the dependent concurrent variable‐interval schedules. The sensitivity of choice to relative reinforcer frequency was independent of the decrease in stimulus discriminability with increasing

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-87

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Eight pigeons were exposed to independent concurrent schedules. Concurrent variable‐interval 60‐second variable‐interval 60‐second schedules were presented to one group of four subjects. Following baseline training, a limited hold was added to one of the schedules and the duration of the hold was decreased in successive conditions. Concurrent variable‐interval 120‐second variable‐interval 40‐second schedules were presented to another group of four subjects. These subjects were first exposed to decreasing durations of a limited hold in the variable‐interval 40‐second component. After replication of the baseline, a limited hold in the variable‐interval 120‐second component was decreased in duration. The initial durations of the holds were determined from the subjects' responding in the baseline conditions. A duration was chosen such that approximately 25% of the scheduled reinforcers would be canceled if responding remained unchanged.Approximate matching of time proportions and reinforcement proportions was observed when the limited hold was added to the variable‐interval 60‐second schedule and when the limited hold was added to the variable‐interval 40‐second schedule. Time proportions were less extreme than reinforcement proportions when the limited hold operated in a variable‐interval 120‐second schedule. Overall reinforcement rates tended to decrease with continued training in concurrent schedules with a limited hold. Absolute deviations from time matching also decreased. The results provide evidence against the principle of reinforcement maximization, and support Herrnstein and Vaug

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-113

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Pigeons were exposed to schedules that consisted of two sequential fixed ratios, the completion of each followed by food delivery. When each alternative provided two food deliveries per 100 responses, the schedule with the shorter initial fixed‐ratio value was consistendy preferred. Subsequent attempts were made to shift this established preference by (1) increasing the ratio requirement in the second fixed ratio of the preferred schedule; (2) increasing the duration of food delivery in the second fixed ratio of the nonpreferred schedule; (3) decreasing the duration of food delivery in the first fixed ratio of the preferred schedule; and (4) shortening the second fixed ratio of the nonpreferred schedule. Preference shifted from the schedule with the shorter initial fixed ratio only when the duration of food delivery associated with the first fixed ratio of that schedule was too brief to allow eating. Under all other conditions, pigeons strongly preferred the schedule with the shorter initial fixed ratio even when, overall, that schedule yielded briefer access to food or required more responses to obtain equivalent acces

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-127

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A new experimental chamber is described that permits rats to demonstrate behavioral preference for one of two conditions by running towards a goal chamber by one of two routes that are correlated with the different conditions. In a preliminary study, rats chose a route correlated with relatively lower shock, demonstrating the sensitivity of the apparatus. We also report evidence using this device that, of 10 rats tested, all preferred unsignaled rather than signaled, inescapable, unavoidable shock.

ISSN:0022-5002    

DOI:10.1901/jeab.1984.42-137

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY