摘要:

In research on directed forgetting in pigeons using delayed matching procedures, remember cues, presented in the delay interval between sample and comparisons, have been followed by comparisons (i.e., a memory test), whereas forget cues have been followed by one of a number of different sample‐independent events. The source of directed forgetting in delayed matching to sample in pigeons was examined in a 2 × 2 design by independently manipulating whether or not forget‐cue trials in training ended with reinforcement and whether or not forget‐cue trials in training included a simultaneous discrimination (involving stimuli other than those used in the matching task). Results were consistent with the hypothesis that reinforced responding following forget cues is sufficient to eliminate performance deficits on forget‐cue probe trials. Only when reinforcement was omitted on forget‐cue trials in training (whether a discrimination was required or not) was there a decrement in accuracy on forget‐cue probe trials. When reinforcement is present, however, the pattern of responding established during and following a forget cue in training may also play a role in the directed forgetting effect. These findings support the view that much of the evidence for directed forgetting using matching procedures may result from motivational and behavioral artifacts rather than the lo

ISSN:0022-5002    

DOI:10.1901/jeab.1995.63-127

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

In an adjusting‐delay choice procedure, pigeons could peck on either a red key or a green key. A peck on the red key always led to a delay associated with red houselights and then food. The delay was adjusted over trials to estimate an indifference point—a delay at which the two keys were chosen about equally often. In some conditions, a peck on the green key led to food on all trials after delays of either 10 s or 30 s, and green houselights were lit during the delays. In other conditions, food was presented on only half of the green‐key trials. If the green houselights continued to occur on both reinforcement and nonreinforcement trials, preference for the green key always decreased. Preference for the green key also decreased if half of the trials had 30‐s houselights followed by food and the other half had no green houselights and no food. However, preference for the green key actually increased if half of the trials had 10‐s green houselights followed by food and the other half had no green houselights followed by no food. The latter condition therefore demonstrated a case in which preference for an alternative increased when food was removed from half of the trials. The results suggest that the red and green houselights served as conditioned reinforcers. A hyperbolic decay model (Mazur, 1989) provided good predictions for all conditions by assuming that the strength of a conditioned reinforcer is inversely related to the total time spent in its presence before food is

ISSN:0022-5002    

DOI:10.1901/jeab.1995.63-139

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Six hens were exposed to several concurrent (second‐order) variable‐interval schedules in which the response requirements on the alternatives were varied. The response requirements were one key peck versus five key pecks, one key peck versus one door push, and five key pecks versus one door push. Response‐ and time‐allocation ratios undermatched the obtained reinforcement ratios but were well described by the generalized matching law. Time and response bias estimates from two pairs of response requirements were used to predict bias in the third pairing. The predicted values were close to those obtained; this result supports the notion that both numerically and topographically different responses act as constant sources of bias within the generalized matching law. The differences between the response and time biases could be accounted for by the different times needed to complete each response requirement. The results also suggest that the door push is a useful operant for research with domest

ISSN:0022-5002    

DOI:10.1901/jeab.1995.63-151

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Pigeons successfully learned to discriminate color slides of paintings by Monet and Picasso. Following this training, they discriminated novel paintings by Monet and Picasso that had never been presented during the discrimination training. Furthermore, they showed generalization from Monet's to Cezanne's and Renoir's paintings or from Picasso's to Braque's and Matisse's paintings. These results suggest that pigeons' behavior can be controlled by complex visual stimuli in ways that suggest categorization. Upside‐down images of Monet's paintings disrupted the discrimination, whereas inverted images of Picasso's did not. This result may indicate that the pigeons' behavior was controlled by objects depicted in impressionists' paintings but was not controlled by objects in cubists' painting

ISSN:0022-5002    

DOI:10.1901/jeab.1995.63-165

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Three experimentally sophisticated chimpanzees (Pan), Akira, Chloe, and Ai, were trained on visual search performance using a modified multiple‐alternative matching‐to‐sample task in which a sample stimulus was followed by the search display containing one target identical to the sample and several uniform distractors (i.e., negative comparison stimuli were identical to each other). After they acquired this task, they were tested for transfer of visual search performance to trials in which the sample was not followed by the uniform search display (odd‐item search). Akira showed positive transfer of visual search performance to odd‐item search even when the display size (the number of stimulus items in the search display) was small, whereas Chloe and Ai showed a transfer only when the display size was large. Chloe and Ai used some nonrelational cues such as perceptual isolation of the target among uniform distractors (so‐called pop‐out). In addition to the odd‐item search test, various types of probe trials were presented to clarify the controlling relations in multiple‐alternative matching to sample. Akira showed a decrement of accuracy as a function of the display size when the search display was nonuniform (i.e., each “distractor” stimulus was not the same), whereas Chloe and Ai showed perfect performance. Furthermore, when the sample was identical to the uniform distractors in the search display, Chloe and Ai never selected an odd‐item target, but Akira selected it when the display size was large. These results indicated that Akira's behavior was controlled mainly by relational cues of target—distractor oddity, whereas an identity relation between the sample and the target strongly controlled the per

ISSN:0022-5002    

DOI:10.1901/jeab.1995.63-175

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Pigeons were tested in a search task on the surface of a monitor on which their responses were registered by a touch‐sensitive device. A graphic landmark array was presented consisting of a square outline (the frame) and a colored “landmark.” The unmarked goal, pecks at which produced reward, was located near the center of one edge of the frame, and the landmark was near it. The entire array was displaced without rotation on the monitor from trial to trial. On occasional no‐reward tests, the following manipulations were made to the landmark array: (a) either the frame or the landmark was removed; (2) either one edge of the frame or the landmark was shifted; and (3) two landmarks were presented with or without the frame present. On these two‐landmark tests, the frame, when present, defined which was the “correct” landmark. When the frame was absent, the “correct” landmark was arbitrarily determined. Results showed that pecks of 2 pigeons were controlled almost solely by the landmark, pecks of 3 were controlled primarily by the landmark but the frame could distinguish the correct landmark, and 1 bird's behavior was controlled primarily by the frame. Stimulus control in this search task is thus selective and differs across individuals. Comparisons to other search tasks and to other stimulus control exp

ISSN:0022-5002    

DOI:10.1901/jeab.1995.63-187

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Four pigeons responded on multiple schedules arranged on a “main” key in a two‐key experimental chamber. A constant schedule component was alternated with another component that was varied over conditions. On an extra response key, conjoint schedules of reinforcement that operated in both components were arranged concurrently with the multiple schedule on the main key. On the main key, changes in reinforcement rate in the varied component were inversely related to changes in response rates in the constant component (behavioral contrast). On the extra key, some reinforcers were reallocated between components, depending on the schedules in effect on the main key in the varied component. In the varied component, the obtained rates of reinforcement on the extra key were inversely related to main‐key reinforcement rate. In the constant component, extra‐key reinforcer rates were positively related to main‐key reinforcer rates obtained in the varied component, and were not a function of response rates on the extra key. In two comparisons, the rate at which components alternated and the value of the main‐key schedule in the constant component were varied. Consistent with earlier work, long components reduced the extent of contrast. Reductions in contrast as a function of component duration were accompanied by similar reductions in the extent of reinforcer reallocation on the extra key. In the second comparison, lowering the rate of reinforcement in the constant component increased the rate at which extra‐key reinforcers were obtained, reduced the extent of reinforcer reallocation, and reduced contrast. Overall, the results are consistent with the suggestion that some contrast effects are due to the changes in extraneous reinforcement during the constant component, and that manipulations of component duration, and manipulations of the rate of reinforcement in the constant component, affect contrast because they influence the extent of extraneous reinforc

ISSN:0022-5002    

DOI:10.1901/jeab.1995.63-203

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY