摘要:

A pigeon's peck on one key moved a light down one position in a 5 × 5 matrix of lights, while a peck on another key moved the light across one position. Reinforcement depended upon the occurrence of four pecks on each key (moving the matrix light from the top left to the bottom right), and a fifth peck on either key ended a trial without food. Though there were 70 different sequences that led to reinforcement, each of 12 pigeons developed a particular, stereotyped sequence which dominated its behavior (Experiment 1). Extinction produced substantial increases in sequence variability (Experiment 2). Removal of the matrix cues disrupted performance, though it partially recovered with extended training (Experiment 3). The pigeons did not master a contingency which required a different sequence on the current trial than on the previous one (Experiment 4), though they were able to learn to emit sequences which began with either left‐left or left‐right response patterns (Experiment 5). The experiments suggest that contingencies of reinforcement may contribute to the creation of complex units of behavior, and that stereotypy may be a likely consequence of contingent reinforce

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-153

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Pigeons were presented a series of keylight time periods (separated by blackouts) during which two response keys were lit, one by blue light and the other either by orange or green. Blue‐key responses changed the color on the other key. Orange‐key responses sometimes produced food during the first half of a time period; green‐key responses sometimes produced food during the second half. In three experiments, the probability of a green‐key response increased as a function of elapsed time. Experiment 1 compared performance when the duration of the keylight periods was varied across a wide range. Discrimination performance was similar across the range of durations. Experiment 2 varied both relative reinforcement rate and the local reinforcement rate for orange‐key and green‐key responses. These manipulations produced changes in response bias but not discrimination sensitivity. Experiment 3 varied the local temporal placement of reinforcers within time periods and demonstrated that choice behavior was affected by differential reinforcement at different points during the time periods. The results were consistent with previous research on duration discrimination that used psychophysical trials

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-167

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The performance of pigeons trained to detect differences in the duration of stimuli was analysed using a matching model of signal detection. Two white stimuli, S1and S2, differing in duration, were arranged with equal probability on the center key of a three‐key chamber. S1was systematically varied from 5 seconds to 25 seconds while S2remained constant at 30 seconds. On completion of the center‐key stimulus, a peck on the center key turned on the two red side keys. A left‐key response was “correct” when S1had been in effect on the center key and a right‐key response was “correct” on S2trials. A correct response produced a 3‐second magazine light accompanied intermittently by food. Incorrect responses produced 3‐second blackouts. Detection performance was measured under two procedures. In the first, the obtained reinforcement ratio was uncontrolled by allowing the number of food reinforcements obtained for correct left‐ and right‐key responses to vary as the stimuli were changed. In the second procedure, the presentation of food reinforcement was controlled by holding the obtained reinforcement ratio constant. Discriminability changed as a function of stimulus differences under both procedures. No such trend was

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-187

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Higher rates of pecking were maintained by pigeons in the middle component of three‐component chained fixed‐interval schedules than in that component of corresponding multiple schedules (two extinction components followed by a fixed‐interval component). This rate difference did not occur in equivalent tandem and mixed schedules, in which a single stimulus was correlated with the three components. The higher rates in components of chained schedules demonstrate a reinforcing effect of the stimulus correlated with the next component; the acquired functions of this stimulus make the vocabulary of conditioned reinforcement appropriate. Problems in defining conditioned reinforcement arise not from difficulties in demonstrating reinforcing effects but from disagreements about which experimental operations allow such reinforcing effects to be called condit

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-213

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Responding in multiple periodic and aperiodic schedules of equal mean reinforcement rate was examined during extinction, satiation, and in the presence of various free‐food schedules. In Experiments I and II, pigeons were trained on multiple variable‐interval‐fixed‐interval schedules. Decreases in the rate of responding due to extinction, satiation, or food schedules were approximately equal regardless of the temporal pattern of reinforcer presentation. In Experiment III, pigeons responded on a two‐component multiple schedule in which each component was a two‐member homogeneous response chain terminating in a fixed‐interval schedule during one component and in a variable‐interval schedule during the other. The length of both terminal links was varied over a series of conditions. Initial‐link responding in the fixed‐interval component was reduced more by increasing terminal‐link length than was initial‐link responding in the variable‐interval component. However, no differences in resistance to satiation and extinction were obtained across the fixed and variable components. If the relative decrease in responding produced by satiation and extinction is used as an index of the “value” of the conditions maintaining responding, then these data suggest that fixed and variable schedules of equal mean length are equally valued. This conclusion, however, is not consistent with findings of preference for variable over fixed schedules obtained in studies usin

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-221

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Five rats were trained under alternative fixed‐ratio fixed‐interval schedules, in which food reinforcement was provided for the completion of either a fixed‐ratio or a fixed‐interval requirement, whichever was met first. Overall response rate and running rate (the rate of responding after the postreinforcement pause) decreased for all subjects as the fixed‐ratio value increased. As the proportion of reinforcements obtained from the fixed‐ratio component increased and the alternative schedule approached a simple fixed ratio, overall response rate and running rate both increased; conversely, as the proportion of reinforcements obtained from the fixed‐interval component increased and the alternative schedule approached a simple fixed interval, response rates decreased. Postreinforcement pause length increased linearly as the average time between reinforcements increased, regardless of the schedule parameters. A break‐run pattern of responding was predominant at low‐and medium‐valued fixed ratios. All subjects displayed at least occasional positively accelerated responding within interreinforcement intervals at higher

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-243

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

In Experiment 1, autoshaping trials terminated with food only if pigeons emitted more than a target number of responses during a trial in one condition and fewer than a target number in another. The median number of responses per trial shifted in accordance with the requirements. The responding of yoked‐control birds that received response‐independent reinforcers did not vary with the response requirements. In Experiment 2, the number of responses in an autoshaping trial became the discriminative stimulus for reinforcement in the second component of a chained schedule. In one condition, responding was reinforced only if the number of responses in the first component was above a target value; in the other condition, responding was reinforced only if the number was below the target value. The distribution of the first‐component response numbers did not shift systematically between discrimination conditions, but response rates in the second component indicated that the number of responses in the autoshaping trial was a discriminable property of beh

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-253

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Rats were trained on a free‐operant procedure in which shock duration was controlled by responses within a limited range of interresponse times. Shocks of 1.6‐mA intensity occurred randomly with average density of 10 shocks per minute. As long as interresponse times were 15 seconds or less, any shocks received were at the briefer of two durations (.3 second). Whenever interresponse times exceeded 15 seconds, any shocks received were at the longer duration (1.0 second). For six of eight animals, avoidance responding developed quickly and reached levels of better than 90%. Four yoked animals stopped responding within the first few sessions. Shock duration reduction without change in shock probability or intensity was sufficient for the acquisition and maintenance of avoidance respond

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-265

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Classical pairings of a sound stimulus with shock elicited larger magnitude and more rapidly conditioned autonomic responses when subjects were responding on variable‐interval schedules for food than when they were eating freely available food. The difference was not attributable to changes in control values of heart rate and blood pressure, or to alterations in motor activity, but appeared related to operant suppressio

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-275

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

An analysis of some extreme forms of stimulus control that a simple conditional‐discrimination procedure can generate leads to the conclusion that accuracy does not provide an orderly scale of measurement. Dependence on accuracy to evaluate a conditional discrimination, particularly at intermediate levels of accuracy, can generate erroneous conclusions about the extent to which the controlling relations are those specified by the experimente

ISSN:0022-5002    

DOI:10.1901/jeab.1980.33-285

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY