摘要:

The peak procedure was used to study temporal control in pigeons exposed to seven fixed‐interval schedules ranging from 7.5 to 480 s. The focus was on behavior in individual intervals. Quantitative properties of temporal control depended on whether the aspect of behavior considered was initial pause duration, the point of maximum acceleration in responding, the point of maximum deceleration, the point at which responding stopped, or several different statistical derivations of a point of maximum responding. Each aspect produced different conclusions about the nature of temporal control, and none conformed to what was known previously about the way ongoing responding was controlled by time under conditions of differential reinforcement. Existing theory does not explain why Weber's law so rarely fit the results or why each type of behavior seemed unique. These data fit with others suggesting that principles of temporal control may depend on the role played by the particular aspect of behavior in particular situation

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-1

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Fixed‐interval performances of rats were described either in terms of the individual intervals of the session or in terms of a single average interval constructed for the entire session. Responding in the individual intervals usually followed break‐and‐run and single response patterns rather than the scalloped pattern that emerged when the results were averaged. There was, however, a reasonable correspondence between the quarter‐life values calculated from individual intervals and those calculated from the averages. According to the pattern exhibited by the average interval, the probability of a response increased as the interval elapsed. The same conclusion was indicated by more molecular analyses of the conditional probabilities of pause terminations. The results showed that descriptions of fixed‐interval data in terms of overall averages reveal aspects of performance that are not immediately apparent within individual

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-11

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

In the behavioral theory of timing, pulses from a hypothetical Poisson pacemaker produce transitions between states that are correlated with adjunctive behavior. The adjunctive behavior serves as a discriminative stimulus for temporal discriminations. The present experiments tested the assumption that the average interpulse time of the pacemaker is proportional to interreinforcer interval. Responses on a left key were reinforced at variable intervals for the first 25 s since the beginning of a 50‐s trial, and right‐key responses were reinforced at variable intervals during the second 25 s. Psychometric functions relating proportion of right‐key responses to time since trial onset, in 5‐s intervals across the 50‐s trial, were sigmoidal in form. Average interpulse times derived by fitting quantitative predictions from the behavioral theory of timing to obtained psychometric functions decreased when the interreinforcer interval was decreased and increased when the interreinforcer interval was increased, as predicted by the theory. In a second experiment, average interpulse times estimated from trials without reinforcement followed global changes in interreinforcer interval, as predicted by the theory. Changes in temporal discrimination as a function of interreinforcer interval were therefore not influenced by the discrimination of reinforcer occurrence. The present data support the assumption of the behavioral theory of timing that interpulse time is determined by interreinforcer

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-19

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Male Siamese fighting fish,Betta splendens, swam through a ring in an aquarium, breaking a photocell beam and initiating an unsignaled, resetting delay interval. Following delays of 0 s, 10 s, or 25 s, a 15‐s mirror presentation released an aggressive display by the fish. Swimming through the ring increased in the absence of either a period of acclimatization to the reinforcer (analogous to magazine training when appetitive reinforcers are used) or explicit training of the response by the experimenters. Response rates were a decreasing function of delay duration. Other fish exposed to a schedule of response‐independent mirror presentations failed to acquire and maintain the response. The results demonstrate the robustness and generality of the phenomenon of response acquisition with delayed reinforcement. They further qualify earlier observations about behavioral mechanisms involved in the phenome

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-35

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Six pigeons were trained on two‐ and three‐alternative concurrent schedules in which the alternatives were signaled by different wavelengths of light on the main pecking key. The schedules were arranged according to a switching‐key procedure in which pecks on a white side key produced a 3‐s blackout and, intermittently, a change in the variable‐interval schedule of food programmed on the main (center) key after the blackout. In Part 1, a two‐alternative concurrent variable‐interval schedule was arranged in which the alternatives were signaled by 560 nm and 630 nm. Parts 2 and 3 arranged three‐alternative concurrent variable‐interval schedules with the alternatives signaled by 560 nm, 600 nm, and 630 nm (Part 2) and 560 nm, 623 nm, and 630 nm (Part 3). Within each part, the relative rate of food reinforcers available on the alternatives was varied across a wide range. In all parts of the experiment, the ratios of responses emitted between pairs of alternatives were more extreme than the ratios of reinforcers obtained on the pairs of alternatives, a result termed overmatching. In Parts 2 and 3, generalized matching sensitivities between pairs of alternatives were found to be higher when the reinforcer rate on the third alternative was low than when it was high—an apparent failure of the constant‐ratio rule. The data were well described by an extension of the Davison and Jenkins (1985) model, which assumes differing discriminabilities between concurrent‐schedule alternatives in combination with a punishing effect of blackou

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-45

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Herrnstein's (1970) hyperbolic matching equation describes the relationship between response rate and reinforcement rate. It has two estimated parameters,kandRe. According to one interpretation,kmeasures motor performance andRemeasures the efficacy of the reinforcer maintaining responding relative to background sources of reinforcement. Experiment 1 tested this interpretation of theReparameter by observing the effect of adding and removing an additional source of reinforcement to the context. Using a within‐session procedure, estimates ofRewere obtained from the response—reinforcer relation over a series of seven variable‐interval schedules. A second, concurrently available variable‐interval schedule of reinforcement was added and then removed from the context. Results showed that when the alternative was added to the context, the value ofReincreased by 107 reinforcers per hour; this approximated the 91 reinforcers per hour obtained from this schedule. Experiment 2 investigated the effects of signaling background reinforcement onkandRe. The signal decreasedRe, but did not have a systematic effect onk. In general, the results supported Herrnstein's interpretation that in settings with one experimenter‐controlled reinforcement source,Reindexes the strength of the reinforcer maintaining responding relative to uncontrolled background sources of rein

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-65

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

In three experiments, pigeons chose between a small amount of food delivered after a short delay and a larger amount delivered after a longer delay. A discrete‐trial adjusting‐delay procedure was used to estimate indifference points—pairs of delay—amount combinations that were chosen about equally often. In Experiment 1, when additional reinforcers were available during intertrial intervals on a variable‐interval schedule, preference for the smaller, more immediate reinforcer increased. Experiment 2 found that this shift in preference occurred partly because the variable‐interval schedule started sooner after the smaller, more immediate reinforcer, but there was still a small shift in preference when the durations and temporal locations of the variable‐interval schedules were identical for both alternatives. Experiment 3 found greater increases in preference for the smaller, more immediate reinforcer with a variable‐interval 15‐s schedule than with a variable‐interval 90‐s schedule. The results were generally consistent with a model that states that the impact of any event that follows a choice response declines according to a hyperbolic function with increasing time since

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-83

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

This experiment examined the relationship between two qualitatively different reinforcers and the parameters of a quantitative model of reinforced responding, referred to as the response‐strength equation or the Herrnstein equation. A group of rats was first food deprived and later water deprived. An 11.5% sucrose solution served as the reinforcer in the food‐deprivation condition, and water was the reinforcer in the water‐deprivation condition. Each experimental session consisted of a series of seven variable‐interval schedules, providing reinforcement rates that varied between 20 and 1,200 reinforcers per hour. The response rates increased in a negatively accelerating function in a manner consistent with the response‐strength equation. This equation has two fitted parameters,kandRe. According to one theory, thekparameter is a measure of motor performance, andReis indicative of the relative reinforcement efficacy of the background uncontrollable sources of reinforcement in relation to the experimentally arranged reinforcer. In this study,kdid not change as a result of the different reinforcers, butRewas significantly larger in the sucrose‐reinforcement condition. These results are consistent with the interpretation thatkandRemeasure two independent and experimentally distinguishable parameters and provide further evidence that absolute response rate is a function of relative reinforcement rate, as implied by the derivation of the response‐strength equation based on the

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-97

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

McLean (1992) presented significant data showing that the occurrence of behavioral contrast in a multiple schedule was correlated with shifts in the frequency of reinforcers from a second source between components of the schedule, and interpreted his results as showing that contrast was due to changes in the degree of response competition within the constant component of the multiple schedule. Reanalysis of his data shows that there was an effect of reinforcement in the alternative component of the schedule independent of the shifts in reinforcers between components. Thus, the effect of relative rate of reinforcement cannot be ascribed, at least entirely, to the mechanisms proposed by the behavioral competition theory of contrast.

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-107

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

An extension of the generalized matching law incorporating context effects on terminal‐link sensitivity is proposed as a quantitative model of behavior under concurrent chains. The contextual choice model makes many of the same qualitative predictions as the delay‐reduction hypothesis, and assumes that the crucial contextual variable in concurrent chains is the ratio of average times spent, per reinforcement, in the terminal and initial links; this ratio controls differential effectiveness of terminal‐link stimuli as conditioned reinforcers. Ninety‐two concurrent‐chains data sets from 19 published studies were fitted to the model. Averaged across all studies, the model accounted for 90% of the variance in pigeons' relative initial‐link responding. The model therefore demonstrates that a matching law analysis of concurrent chains—the assumption that relative initial‐link responding equals relative terminal‐link value—remains quantitatively viable. Because the model reduces to the generalized matching law when terminal‐link duration is zero, it provides a quantitative integration of concurrent schedules

ISSN:0022-5002    

DOI:10.1901/jeab.1994.61-113

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY