ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-1

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

For three pigeons (Experiment 1), the presentation of a red response key ended with a food presentation either following two responses separated by at least 10 seconds (a DRL contingency) or following a 10‐second response‐free period (a DRO contingency). For three other birds (Experiment 2), a brief stimulus presentation terminated the DRL and DRO contingencies. A white side key was presented next and ended with response‐dependent food following one contingency and a timeout following the other. Since the contingency on the red key was unsignaled, differential responding on the white side key could indicate that the two response‐reinforcer relations had been discriminated. In Experiment 1, the red‐key duration and number of responses influenced white‐key responding following the contingency that predicted the timeout. A response‐initiated DRO was instated, and the influence of red‐key duration and response number on white‐key responding was diminished. In both experiments, the 10‐second time criterion in both contingencies was varied from 0.34 second to 10 seconds. Even at short time intervals the DRO and DRL contingencies were readily discriminated. Pigeons tended to class the two contingencies according to a rule that did not involve simply stimulus duration, numbers of responses, or even the time between a response

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-7

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A critical issue in testing theories of observing is whether the stimulus associated with extinction (the S—) reinforces observing responses. In previous experiments, subjects have been trained to make observing responses that produce both the S— and the stimulus correlated with reinforcement (the S+). Then, either the S+ or the S— has been withheld. Conflicting results have been attributed to differences among species. In the present experiments, pecking one key by master pigeons was reinforced with grain on a variable‐ratio extinction schedule. Yoked pigeons received the grain on a variable‐interval, extinction schedule controlled by the variable‐ratio performances of the master birds. For both groups, concurrent pecking on a second key was reinforced on a variable‐interval schedule with displays of discriminative stimuli. Subsequently, either the S+ or the S— was eliminated from the procedure. Omission of S+ produced a large decrease, as predicted by traditional conditioned reinforcement accounts of observing. By itself, S— did not maintain observing. A smaller and less reliable decrease, comparable to that obtained by Lieberman (1972) with rhesus monkeys, occurred when S— was eliminated. This replication with pigeons of Lieberman's results indicates that they are not species‐specific, and the fact that observing was not maintained by S— alone suggests that the decrease obtained when S— was omitted is not attributable to th

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-17

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

After key pecking had been autoshaped, six pigeons were exposed to a condition in which the duration of grain availability at the end of an 8‐second trial depended on the number of responses emitted during the trial (0.25‐second access to grain per response). This procedure, called correlated reinforcement, alternated across conditions with the automaintenance baseline in which the 8‐second trial terminated with a constant 2.5‐second access to grain. Two control procedures were run; in both, the reinforcer durations were yoked to those obtained in the last correlated session. In the yoked control no responses were required, but in the single‐response yoked control at least one response was required to receive the yoked duration. The correlated condition maintained response rates above those produced by the two control conditions. These results may be accounted for by differential rein

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-27

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Previous experiments have shown that both cocaine andd,l‐cathinone can function as positive reinforcers when delivered intravenously to rhesus monkeys. However, the relative reinforcing efficacies of these compounds have not been established. In the present experiment, three rhesus monkeys were allowed to choose between saline and several doses ofd,l‐cathinone or cocaine as well as between several doses of both drugs in a discrete‐trial choice procedure. Sufficient doses (.05 to .2 mg/kg/injection) of either drug maintained self‐administration and the higher doses were reliably preferred to saline. Doses ofd,l‐cathinone that were preferred to saline were then compared to a range of cocaine doses in drug‐drug choice. As the dose ofd,l‐cathinone that was available was increased, an increase in cocaine dose was necessary to maintain cocaine preference. Comparison of drug‐drug choice data to dose combinations predicted to be chosen with equal frequency revealed that the reinforcing efficacy ofd,l‐cathinone was equivalent t

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-35

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Experiment 1 tested whether a “symmetrical” choice procedure yields results different from those previously reported using the “unidirectional” standard changeover procedure (e.g., Badia&Culbertson, 1972). Subjects could change at any time from unsignaled to signaled shock by pressing a lever and from signaled to unsignaled shock by pressing a second lever. Results were identical to those of the standard procedure and showed that the standard procedure is fully adequate. Experiment 2 tested whether choice of high density signaled shock over low‐density unsignaled shock (Badia, Coker,&Harsh, 1973) resulted from initial training with equal‐density schedules. Subjects were trained and tested with signaled shock twice as dense as unsignaled shock. Three of four subjects strongly preferred the signaled condition, thus ruling out carry‐over and “response fixation” as alterna

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-45

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Previous quantitative models of choice in a self‐control paradigm (choice between a larger, more‐delayed reinforcer and a smaller, less‐delayed reinforcer) have not described individual differences. Two experiments are reported that provide additional quantitative data on experience‐based differences in choice between reinforcers of varying sizes and delays. In Experiment 1, seven pigeons in a self‐control paradigm were exposed to a fading procedure that increased choices of the larger, more‐delayed reinforcer through gradually decreasing the delay to the smaller of two equally delayed reinforcers. Three control subjects, exposed to each of the small‐reinforcer delays to which the experimental subjects were exposed, but for fewer sessions, demonstrated that lengthy exposure to each of the conditions in the fading procedure may be necessary in order for the increase to occur. In Experiment 2, pigeons with and without fading‐procedure exposure chose between reinforcers of varying sizes and delays scheduled according to a concurrent variable‐interval variable‐interval schedule. In both experiments, pigeons with fading‐procedure exposure were more sensitive to variations in reinforcer size than reinforcer delay when compared with pigeons without this exposure. The data were described by the generalized matching law when the relative size of its exponents, representing subjects' relative sensitivity to reinforcer size and delay, were grouped according to

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-53

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Pigeons' responses in two successive components of multiple schedules were reinforced according to variable‐interval schedules of reinforcement that varied over five different conditions. Within each session of all conditions, line orientations of 0°, 30°, or 45° in Component 1 alternated with orientations of 45°, 60°, or 90° in Component 2. Response rates were recorded in three successive subintervals of each component. Ratios were taken between the response rate in each Component 1 line orientation and the response rate in each Component 2 orientation. These ratios were found to be power functions of the corresponding ratios of obtained reinforcement rates. Sensitivity of response ratios to changes in reinforcer ratios, given by the value of the exponent of the power function, increased systematically with increasing disparity between the dimensional values of orientation stimuli. In addition, sensitivity decreased systematically over successive subintervals of components, that is, with increasing time since component alternation. Dimensional and local (subinterval) effects interacted in that sensitivity increased with stimulus disparity to a far greater extent in the first subinterval than later in components. The data could be described by a combination of rectangular hyperbolae which attributed the interaction between local and dimensional effects to limits set by local effects on the extent that stimulus differences could affect sens

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-69

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Herrnstein and Heyman (1979) showed that when pigeons' pecking is reinforced on concurrent variable‐interval variable‐ratio schedules, (1) their behavior ratios match the ratio of the schedules' reinforcer frequencies, and (2) there is more responding on the variable interval. Since maximizing the reinforcement rate would require responding more on the variable ratio, these results were presented as establishing the primacy of matching over maximizing. In the present report, different ratios of behavior were simulated on a computer to see how they would affect reinforcement rates on these concurrent schedules. Over a wide range of experimenter‐specified choice ratios, matching obtained — a result suggesting that changes in choice allocation produced changes in reinforcer frequencies that correspond to the matching outcome. Matching also occurred at arbitrarily selected choice ratios when reinforcement rates were algebraically determined by each schedule's reinforcement‐feedback function. Additionally, three birds were exposed to concurrent variable‐interval variable‐ratio schedules contingent on key pecking in which hopper durations were varied in some conditions to produce experimenter‐specified choice ratios. Matching generally obtained between choice ratios and reinforcer‐frequency ratios at these different choice ratios. By suggesting that reinforcer frequencies track choice on this procedure, instead of vice versa, this outcome questions whether matching‐as‐outcome was due to matching‐as‐process in the He

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-83

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Allen (1981) derived the power‐function generalization of the matching law from a functional equation involving relative response rates on three concurrently available schedules of reinforcement. This paper defines the conditions (relative homogeneity and independence) under which a more general class of behavioral laws reduces to the power law. The proof also removes two deficiencies of Allen's result (discussed by Houston, 1982), which are, first, that his derivation produces a power law without a bias coefficient, and second, that it holds only for experiments with three or more concurrent schedule

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-101

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY