摘要:

The present study assessed a 24‐hr time course for the acute effects of intramuscular injections of atropine sulfate (0, 1.5, 3.0, and 6.0 mg/70 kg) in healthy adult humans responding under a two‐component multiple schedule of repeated acquisition and performance of response sequences. Subjects resided in an inpatient research ward for the duration of the study. In each component of the multiple schedule, subjects completed a different sequence of 10 responses in a predetermined order using three keys of a numeric keypad. In the acquisition component, the subjects' task was to acquire a new sequence each session. Eight sessions were conducted daily: one immediately before administration of the drug and then 0.5, 1.5, 3.0, 5.0, 7.0, 9.0, and 24.0 hr after administration. In the performance component, the response sequence always remained the same. Overall percentage of errors increased and overall response rates decreased in the acquisition and performance components as an orderly function of drug dose. However, these effects were selective in that behavior in the acquisition component generally was affected at lower doses than in the performance component. When behavior was affected in both the acquisition and performance components, the time courses of effects were similar. Drug effects began at 0.5 or 1.5 hr, reached peak effects between 3.0 and 5.0 hr, and returned to placebo levels between 7.0 and 9.0 hr postdrug in both schedule components. None of the drug doses produced reliable effects the day after drug administration (24‐hr postdrug) in either schedule component. The present study provides the first within‐subject assessment of the magnitude and duration of the effects of an anticholinergic on repeated acquisition and performance baselines and extends to atropine the selective effects on these two baselines demonstrated previously with other compounds in humans and no

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-5

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The purpose of the present study was to evaluate Herrnstein's law of effect as a description of socially significant behavior in an applied setting. The subject was an 18‐year‐old retarded girl with a history of autistic‐like and aggressive behavior. Using a baseline design for two response classes and stimulus conditions, eight categories of subject and staff behavior were monitored over a 3‐week period. A computerized observation system, developed for use in the present investigation, was used to obtain real‐time durations of the behavior categories alone and in combination. Overlapping durations of teacher and subject behavior were then correlated to yield approximations to a functional definition of reinforcement. Plots of behavior by contingent reinforcement revealed a hyperbolic relationship for each response class, the shape of which varied as a function of extraneous reinforcementr0. In addition, estimated parameters in Herrnstein's equation did not differ significantly from those obtained through independent observation. Finally, Herrnstein's equation accounted for an average 63% of variance in response allocation. Results are discussed in terms of the relevance of matching‐law theory to behavior in appli

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-17

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Three college students in Experiment 1 and 1 student in Experiment 2 learned visual conditional discriminations under contextual control by tones; the visual comparison stimulus that was correct with a given sample stimulus depended on whether a high tone or a low tone was present. Two of the subjects in Experiment 1 then demonstrated the emergence of two sets of contextually controlled three‐member classes of equivalent stimuli, and the subject in Experiment 2 showed the emergence of contextually controlled four‐member classes; the class membership of each stimulus varied as a function of the tones. Class membership was demonstrated by the subjects' performance of new conditional discriminations that they had never been taught directly. In Experiment 2, the procedures were intended to ensure that the tones exerted second‐order conditional control and did not simply form compounds with each of the visual stimuli, but the subject's verbal description of the tasks suggested that this intention might not have been successful. It could not be ascertained, therefore, whether the tones exerted contextual control as independent second‐order conditional stimuli or simply as common elements of auditory—visual stimulus

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-29

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

After children in Experiments 1 and 2 learned identity matching or oddity, control by sample‐comparison relations was assessed. Tests for generalized control displayed novel samples and two comparison stimuli, one identical to the sample. Specific relations were tested with identical or nonidentical sample‐comparison stimuli from one set of stimuli and substitute comparisons from either the other training set or from a novel set. When tests displayed identical stimuli, patterns of comparison selection suggested control by generalized identity and oddity. However, selection patterns varied when stimuli were nonidentical and familiar or novel substitute comparisons were used. Therefore, control by specific relations is not a precondition for generalized identity and oddity. One set of training stimuli was used in Experiment 3, and generalized performances occurred again. Moreover, control by specific relations was shown by the oddity subjects and 2 of 6 identity subjects. Generalized and specific control may therefore exist simultaneously. In Experiment 4, selections were irregular on tests displaying substitute comparisonsandsamples and familiar comparison stimuli; this finding supported the relational account of specific sample‐comparison control found in Experim

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-47

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

This study examined stimulus class membership established via stimulus—reinforcer relations. Mentally retarded subjects learned conditional discriminations with four two‐member sets of visual stimuli (A, B, C, and D). On arbitrary‐matching trials, they selected comparison stimuli B1 and B2 conditionally upon samples A1 and A2, respectively, and C1 and C2 conditionally upon B1 and B2, respectively. On identity‐matching trials, they selected all stimuli as comparisons conditionally upon identical stimuli as samples. Throughout training, correct selections of A1, B1, C1, and D1 were followed by one reinforcer, R1, and those of A2, B2, C2, and D2 were followed by another, R2. Subsequent tests documented the formation of two four‐member stimulus classes, A1‐B1‐C1‐D1 and A2‐B2‐C2‐D2. The class membership of the A, B, and C stimuli could have been based on equivalence relations that resulted from the arbitrary‐matching training. D1 and D2 had never appeared on arbitrary‐matching trials, however. Their class membership must have been based on relations with R1 and R2, respectively. Results thus confirm a previous finding that stimulus classes can be expanded via stimulus—reinforcer relations. They also define more precisely the potential nature of those classes and the conditions under which class me

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-65

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Sixteen girls (ages 4, 6, 9, and 12) performed on concurrent‐chain schedules of reinforcement. The initial links were variable‐interval 10‐s schedules, and the terminal links offered a long delay (20, 30, 40, or 50 s) followed by two tokens or a short delay (10 s) followed by one token. Tokens were used to buy toys and sweets. The effect of increasing the delay to the large reward differed significantly across age groups. Whereas 6‐ and 9‐year‐olds maintained a strong preference for the larger, more delayed reward under all delay conditions, half of the 4‐year‐olds and all the 12‐year‐olds showed increasing preference for the small reward as the delay to the large reward increased. The results suggest a two‐stage account of the development of self‐control. In the first stage, behavior is increasingly controlled by reward size, as children learn how to wait for delayed rewards, and in the second phase behavior is increasingly controlled by reward rate, as children learn when it is in

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-77

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

In three experiments, pigeons chose between two alternatives that differed in the probability of reinforcement and the delay to reinforcement. A peck at a red key led to a delay of 5 s and then a possible reinforcer. A peck at a green key led to an adjusting delay and then a certain reinforcer. This delay was adjusted over trials so as to estimate an indifference point, or a duration at which the two alternatives were chosen about equally often. In Experiments 1 and 2, the intertrial interval was varied across conditions, and these variations had no systematic effects on choice. In Experiment 3, the stimuli that followed a choice of the red key differed across conditions. In some conditions, a red houselight was presented for 5 s after each choice of the red key. In other conditions, the red houselight was present on reinforced trials but not on nonreinforced trials. Subjects exhibited greater preference for the red key in the latter case. The results were used to evaluate four different theories of probabilistic reinforcement. The results were most consistent with the view that the value or effectiveness of a probabilistic reinforcer is determined by the total time per reinforcer spent in the presence of stimuli associated with the probabilistic alternative. According to this view, probabilistic reinforcers are analogous to reinforcers that are delivered after variable delays.

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-87

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

In five experiments we studied the effects on pigeons' key pecking of the location of four or more successive response‐dependent reinforcers imbedded in a schedule arranging otherwise response‐independent reinforcers. In Experiment 1, high local response rates early in the session were extended farther into the session as the number of response‐dependent reinforcers at the beginning of the session increased. A block of four successive response‐dependent reinforcers then was scheduled at the beginning, middle, or end of the session (Experiment 2) resulting in higher local response rates at those times in the session when the response‐dependent reinforcers were arranged. When placed in random locations in successive sessions (Experiment 3), uniform local rates occurred throughout the session. In Experiments 1, 2, and 3, delivery of the remaining response‐independent reinforcers was precluded until the response‐dependent reinforcers were collected. Experiment 4 was similar to Experiments 1 and 2, except that all response‐independent reinforcers occurred irrespective of whether the response‐dependent reinforcers had been collected. This yielded results similar to those obtained in the first two experiments. In Experiment 5, responding early in the session had no consequence other than allowing access to the schedule of response‐independent food delivery. As in the first experiment, local rates generally were higher early in the session. The results indicate that the location of response‐reinforcer dependencies precisely control behavior and that such effects often are not captured by descriptions of behavior in terms of o

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-101

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Six pigeons were trained with a chain variable‐interval variable‐interval schedule on the left key and with reinforcers available on the right key on a single variable‐interval schedule arranged concurrently with both links of the chain. All three schedules were separately and systematically varied over a wide range of mean intervals. During these manipulations, the obtained reinforcer rates on constant arranged schedules also frequently changed systematically. Increasing reinforcer rates in Link 2 of the chain increased response rates in both links and decreased response rates in the variable‐interval schedule concurrently available with Link 2. Increasing Link‐1 reinforcer rates increased Link‐1 response rates and decreased Link‐2 response rates. Increasing reinforcer rates on the right‐key schedule decreased response rates in Link 1 of the chain but did not affect the rate in Link 2. The results extend and amplify previous analyses of chain‐schedule performance and help define the effects that a quantitative model must describe. However, the complexity of the results, and the fact that constant arranged reinforcer schedules did not necessarily lead to constant obtained reinforcer rates, precluded a quan

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-119

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

A chamber containing 72 response keys defining the circumference of a circle 1 m in diameter was used to examine the relation between differentiation of response location and a measure of response‐reinforcer contingency known as the phi coefficient. A different target key was specified in each successive phase, and response location was differentiated with respect to the target. Criterional and noncriterional responses (i.e., responses “near” and “far” from the target) were defined using targeted percentile schedules to control the overall probability of each response class. By manipulating criterional (and, hence, noncriterional) response probability and the reinforcement probabilities conditional on each, a mathematical in variance property peculiar to phi in contingency analysis was examined. Specifically, diagonally interchanging cell frequencies in a 2 × 2 table relating criterional/noncriterional responses to reinforcement/nonreinforcement leaves phi unchanged. Hence, the degree of response differentiation predicted by phi remains unchanged under the four permutations implied by the various diagonal interchanges. This predicted invariance was examined under values of phi equal to .33, .58, and .82. Increasing phi generally increased the stereotypy of response location. Three of the permutations generated almost interchangeable performance at different phi values. The remaining permutation, however, generated functions relating response concentration to phi with slopes shallower than those obtained under the other permutations. This resulted from relatively higher levels of differentiation, compared to the other permutations, at low phi values. These data strongly suggest boundary conditions on the ability of phi to reflect completely the local processes that are indexed by phi at a m

ISSN:0022-5002    

DOI:10.1901/jeab.1989.51-145

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY