ISSN:0022-5002    

DOI:10.1901/jeab.1980.34-133

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

A concurrent‐chain procedure was used to study pigeons' choices between rewards differing in both amount and delay. The shorter delay terminated with a 2‐second access to grain whereas the longer delay terminated with a 6‐second access to grain. The ratio of the delays was constant within a given condition while their absolute values were varied. Over conditions, ratios of 6:1, 3:1, and 3:2 were studied. As the absolute values of the delays to reinforcement increased, preference for the longer‐delayed but larger reward decreased under both the 6:1 and 3:1 ratios, but increased under the 3:2 ratio. These results are inconsistent with choice models predicting no change in preference when the ratios of delays and amounts are held constant. In addition, the change in preference under the 3:1 ratio is inconsistent with a simple multiplicative interaction of the trade off between reinforcer amount and delay, and suggests that delay is a more potent determinant of choice than is amount. These results have implications for models that view choice between small immediate rewards and large but delayed rewards as underlying the behavior commonly called self

ISSN:0022-5002    

DOI:10.1901/jeab.1980.34-135

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

During three experiments with squirrel monkeys, stimulus and shock pairings were given in the presence of a bite tube. Experiments 1 and 2 used a conditioned‐suppression procedure in which bar pressing was reinforced with food. A transparent shield prevented biting of the bar. When the stimulus was paired with shock, bar pressing decreased (conditioned suppression) and tube biting increased during the stimulus (classically conditioned aggression). When the bite tube was removed on alternate sessions in Experiment 2, there was more suppression when the tube was present, thus suggesting that biting competed with bar pressing. However, this simple competing‐response interpretation was complicated by the findings of Experiment 3 where, with naive monkeys, bar pressing was never reinforced with food, yet bar pressing was induced during the stimulus and was highest when the bite tube was absent. The fact that stimulus‐induced bar pressing developed indicates that bar pressing in conditioned‐suppression procedures, suppressed or not, may be maintained by two types of control—the food reinforcer and induced CS control. The higher rate of induced bar pressing during the stimulus with the bite tube absent confounds a simple competing response interpretation of conditioned suppression. It suggests that shock‐induced responses during conditioned suppression could be both contributing to and competing with responding maintained by food, with the net effect depending on specific but ill‐defined features of

ISSN:0022-5002    

DOI:10.1901/jeab.1980.34-149

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Pigeons were maintained on a multiple schedule in which both components were variable‐interval one‐minute schedules. When they were switched to a condition in which one component was extinction, behavioral contrast was observed. The median durations of the key pecks in the unchanged component did not decrease in size. The results are incompatible with a theory of behavioral contrast which considers the added pecks to be short‐duration responses. In a second experiment, pigeons were required to emit short‐duration key pecks in one component of a multiple schedule, and long‐duration pecks in the other. Two of three pigeons learned to emit responses appropriate to the requirements of the component in effect, suggesting that the duration of the key‐peck response is sensitive to differential re

ISSN:0022-5002    

DOI:10.1901/jeab.1980.34-167

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Pigeons learned to peck the left or right of two white keys depending on whether a red or a green stimulus was displayed on a third key. The opportunity to peck the white keys was then delayed for zero to six seconds after the red or green (to‐be‐remembered) stimulus. On half the trials, the feeder operated during the delay to interrupt behavior that might mediate discriminated responding. No events were scheduled on the remaining trials. In a later condition, the pigeons had the opportunity to peck the white keys during the delay. In general, accuracy decreased as delay increased in all conditions, but performance was least accurate following feeder operations and most accurate when pecking was allowed during the delay. The procedures may be analogous to varying the opportunity for rehearsal in studies of human short‐term m

ISSN:0022-5002    

DOI:10.1901/jeab.1980.34-177

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Key pecking by three pigeons was maintained under a multiple fixed‐interval fixed‐ratio schedule of food presentation. The fixed‐interval value remained at 3 minutes, while the fixed‐ratio size was increased systematically in 30‐response increments from 30 to either 120 (two pigeons) or 150 (one pigeon). At least two lower fixed‐ratio values were also redetermined. The effects of ethanol (.5 to 2.5 g/kg) were assessed at each of the different schedule parameters. Both overall and running response rates under the fixed‐ratio schedule decreased with increases in the size of the fixed‐ratio schedule; pause duration under the fixed‐ratio schedule was directly related to increases in fixed‐ratio size. Overall and running rates of responding under the fixed‐interval schedule changed little with increases in the size of the fixed‐ratio schedule. Despite the relative invariance of fixed‐interval responding across the different fixed‐ratio values, the effects of ethanol on responding under the fixed‐interval schedule differed depending on the size of the fixed‐ratio schedule. Greater increases occurred in both overall and in lower local rates of responding under the fixed‐interval schedule when the fixed‐ratio value was 120 or 150. The effects of ethanol on responding under the fixed‐ratio schedule also depended on the size of the fixed ratio. Increases in responding under the fixed‐ratio schedule were typically greater at the higher fixed‐ratio values where response rates were lower. When the effects of ethanol were redetermined at the lower fixed‐ratio parameter values, rates and patterns of responding were comparable to those obtained initially. However, the dose‐effect curves for responding under both fixed‐ratio and fixed‐interval schedules were shifted up and to the right of those determined during the ascending series. The effects of ethanol can depend on rate of responding, behavioral

ISSN:0022-5002    

DOI:10.1901/jeab.1980.34-185

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1980.34-199

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

On a given variable‐interval schedule, the average obtained rate of reinforcement depends on the average rate of responding. An expression for this feedback effect is derived from the assumptions that free‐operant responding occurs in bursts with a constant tempo, alternating with periods of engagement in other activities; that the durations of bursts and other activities are exponentially distributed; and that the rates of initiating and terminating bursts are inversely related. The expression provides a satisfactory account of the data of three experime

ISSN:0022-5002    

DOI:10.1901/jeab.1980.34-207

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

A review of the relationship between schedule of reinforcement, response rate, and choice suggests that certain unifying concepts from economics can contribute to a more complete science of behavior. Four points are made: 1) a behavioral experiment is an economic system and its characteristics—open or closed—can strongly determine the results; 2) reinforcers can be distinguished by a functional property called elasticity; 3) reinforcers may interact as complements as well as substitutes; 4) no simple choice rule, such as strict matching, can account for all choice behav

ISSN:0022-5002    

DOI:10.1901/jeab.1980.34-219

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY