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51.
The interaction of stimulus and reinforcer control in complex temporal discrimination. 总被引:2,自引:2,他引:0
Six pigeons were trained in a discrete-trials signal-detection procedure to discriminate between a fixed-duration stimulus (5 s or 20 s) and a set of variable durations ranging from 2.5 s to 57.5 s in steps of 5 s. For each fixed-duration stimulus, the ratio of reinforcer frequencies contingent upon reporting the fixed versus the variable stimulus was systematically manipulated. Detection performance was well controlled by both the stimulus value and the reinforcer ratio. Both the discriminability between the fixed duration and the set of variable durations, and the discriminability between the fixed duration and each of the variable durations, were independent of the reinforcer-frequency ratio when discriminability was measured as log d. The sensitivity of response bias to reinforcement-ratio changes was independent of the value of the fixed duration, but was not independent of the discriminability of the variable durations from the fixed durations. Under current models, discriminability measures in complex temporal discrimination may be independent of biasing manipulations, but bias measures are not independent of stimulus values. 相似文献
52.
Pigeons' choices between alternatives that provided different percentages of reinforcement in mixed schedules were studied using the concurrent-chains procedure. In Experiment 1, the alternatives were terminal-link schedules that were equal in delay and magnitude of reinforcement, but that provided different percentages of reinforcement, with one schedule providing, reinforcement twice as reliably as the other. All pigeons preferred the more reliable schedule, and their level of preference was not systematically affected by variation in the absolute percentage values, or in the magnitude of reinforcement. In Experiment 2, preference for a schedule providing 100% reinforcement over one providing 33% reinforcement increased systematically with increases in the duration of the terminal links. In contrast, preference decreased systematically with increases in the duration of the initial links. Experiment 3 examined choice with equal percentages of reinforcement but unequal delays to reinforcement. Preference for the shorter delay to reinforcement was not systematically affected by variation in the absolute percentage of reinforcement. The overall pattern of results supported predictions based on an extension of the delay-reduction hypothesis to choice procedures involving mixed schedules of percentage reinforcement. 相似文献
53.
Effects of delayed conditioned reinforcement in chain schedules. 总被引:3,自引:3,他引:0
The contingency between responding and stimulus change on a chain variable-interval 33-s, variable-interval 33-s, variable-interval 33-s schedule was weakened by interposing 3-s delays between either the first and second or the second and third links. No stimulus change signaled the delay interval and responses could occur during it, so the obtained delays were often shorter than the scheduled delay. When the delay occurred after the initial link, initial-link response rates decreased by an average of 77% with no systematic change in response rates in the second or third links. Response rates in the second link decreased an average of 59% when the delay followed that link, again with little effect on response rates in the first or third links. Because the effect of delaying stimulus change was comparable to the effect of delaying primary reinforcement in a simple variable-interval schedule, and the effect of the unsignaled delay was specific to the link in which the delay occurred, the results provide strong evidence for the concept of conditioned reinforcement. 相似文献
54.
The proposal that peripheral visual changes (cues) tend to summon attention automatically was tested by studying the effect
of peripheral cueing on simple detection latency. Delay between cue onset and target onset, the contingent relationship between
cue location and target location, and instructions to subjects were manipulated. Results showed that a peripheral display
change could capture attention even when the target was far more likely to appear at an uncued location. When subjects were
explicitly informed that targets were likely to appear away from the cued location they were able to suppress this effect,
but were unable completely to reverse it by rapidly orienting attention towards the uncued side. Hence the process appears
to be automatic in the sense that it occurs unless there are explicit instructions to the contrary. With explicit instructions
the processing operation can be suppressed, but not completely reversed.
This work was supported by the U.K. Admiralty Research Establishment (Research Agreement No. 53482). 相似文献
55.
Clinical staff’s attributions about diabetes management were measured using newly developed scales. Eighty-five physicians
and nurses provided data to investigate the psychometric properties of the scales and to examine the patterns of attributions
made. Alpha coefficients for the 7 six-item scales were satisfactory, ranging from .51 to .73. A comparison between attributions
for positive and negative outcomes of diabetes management produced examples of self-serving bias. Comparisons were made with
data from 286 insulin-dependent diabetes patients. Staff tended to rate patients as having less personal control over positive
outcomes (t=2.94;df=338;p<.01) and tended to emphasize chance to a greater extent than did the patients (t=−4.32;df=338;p<.001). There was a tendency for staff to rate negative outcomes as being more foreseeable by the patients than the patients
did themselves (t=−3.11;df=346;p<.01). Both patients and staff demonstrated bias towards dispositional attributions. The implications of between and within
group differences in attribution patterns are discussed.
The research presented here was supported in part by grants from the National Institutes of Health, U.S.A. (No. AM28196) and
from the British Diabetic Association to Dr. C. Bradley. 相似文献
56.
This study set out to investigate the relationship between the Type A behavior pattern, the need for approval, and the need
to prove oneself. One hundred and two subjects completed four questionnaires: two measuring A-type behavior, one social desirability,
and one—especially devised for this study—the belief in the need to prove oneself consistently. Results showed that Type A’s
have significantly lower needs for approval than Type B’s, yet appear to show considerably greater interest in comparing their
achievements with others. It seems that Type A’s do not have any special need to prove their worth to others, but that they
must constantly prove themselves to themselves. Limitations of this preliminary study are discussed. 相似文献
57.
Sixteen student volunteers were administered a placebo and 50 mg. of chlorpromazine in tablet form, on separate occasions,
two hours before testing. The three tests measured dichotic listening performance, lateral eye movements while answering questions
about spatial location and verbal meaning, and lateralized facial expression while relating pleasant and unpleasant life incidents.
Results showed that chlorpromazine increased the number of trials showing an ear advantage in dichotic listening. Chlorpromazine
reduced lateral and increased vertical eye movements in response to the questions about spatial location and verbal meaning.
Under the placebo both negative and positive emotions were expressed more in the left face. Although chlorpromazine did not
affect this lateralization of negative emotions, the expression of positive emotions occurred equally often on the two sides
of the face under chlorpromazine. Results may be related to an effect of chlorpromazine on the asymmetrical dopamine pathways
of the brain. It is suggested that the findings may be related to a left hemisphere deficit in schizophrenia. 相似文献
58.
Observational learning of two visual discriminations by pigeons: a within-subjects design. 下载免费PDF全文
G B Biederman H A Robertson M Vanayan 《Journal of the experimental analysis of behavior》1986,46(1):45-49
Pigeon's observational learning of successive visual discrimination was studied using within-subject comparisons of data from three experimental conditions. Two pairs of discriminative stimuli were used; each bird was exposed to two of the three experimental conditions, with different pairs of stimuli used in a given bird's two conditions. In one condition, observers were exposed to visual discriminative stimuli only. In a second condition, subjects were exposed to a randomly alternating sequence of two stimuli where the one that would subsequently be used as S+ was paired with the operation of the grain magazine. In a third experimental condition, subjects were exposed to the performance of a conspecific in the operant discrimination procedure. After exposures to conspecific performances, there was facilitation of discriminative learning, relative to that which followed exposures to stimulus and reinforcement sequences or exposures to stimulus sequences alone. Exposure to stimulus and food-delivery sequences enhanced performance relative to exposure to stimulus sequences alone. The differential effects of these three types of exposure were not attributable to order effects or to task difficulty; rather, they clearly were due to the type of exposure. 相似文献
59.
DOES EFFORT PLAY A ROLE IN THE EFFECT OF RESPONSE REQUIREMENTS ON DELAYED MATCHING TO SAMPLE? 总被引:2,自引:2,他引:0 下载免费PDF全文
The possible role of "effort" in the accuracy of pigeons' performance on a delayed matching-to-sample procedure was investigated by examining the effects of response requirements that accompanied a trial-initiating stimulus and that accompanied a sample stimulus. In the first experiment, the effect of varying the size of a fixed-ratio requirement for responses during an initiating stimulus was compared to that of varying a similar requirement for responses during the sample stimulus. Accuracy increased reliably with increases in the ratio scheduled during the sample stimulus, but was not significantly affected by increases in the ratio scheduled on the key during the initiating stimulus. In another phase of Experiment 1, sample duration was held constant while the ratio requirement was varied during the initiating stimulus. Again, accuracy of matching to sample was not significantly affected by the size of the ratio scheduled during the initiating stimulus. Experiment 2 provided a systematic replication of these results in another group of pigeons and included a more detailed analysis of responding. These results support the view that increases in sample-response requirement facilitate accuracy of delayed matching by increasing the durations of exposure to the sample stimuli, and do not support a role of effort in the sample-response effect. In Experiment 3, the facilitative effect of responses on the sample but not of those on the initiating stimulus was replicated using a simultaneous matching-to-sample procedure. This finding provides further evidence against an interpretation of response-requirement effects that appeals to effort; the finding also suggests that sample exposure might affect initial discrimination of the sample rather than remembering the sample. 相似文献
60.
R Pisacreta D Gough E Redwood L Goodfellow 《Journal of the experimental analysis of behavior》1986,45(3):269-282
Four pigeons were trained on a multiple variable-interval 30-s extinction schedule with various pairs of spoken English words presented as the discriminative stimuli. The birds typically produced discrimination indices of 70% to 90% accuracy. Discrimination accuracy was improved by shortening the interval between auditory stimulus presentations, and by increasing the number of syllables in the words. 相似文献