摘要:

According to optimal foraging theory, animals should prefer food items with the highest ratios of energy intake to handling time. When single items have negligible handling times, one large item should be preferred to a collection of small ones of equivalent total weight. However, when pigeons were offered such a choice on equal concurrent variable‐interval schedules in a shuttlebox, they preferred the side offering many small items per reinforcement to that offering one or a few relatively large items. This preference was still evident on concurrent fixed‐cumulative‐duration schedules in which choosing the alternative with longer handling time substantially lowered the rate of food i

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-139

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Three‐person groups, either of males or of females, resided for 6 to 12 days in a continuously programmed environment. Subjects followed a behavioral program that determined the sequential and contingent relations within an inventory of activities. The program consisted of positive reinforcement days and avoidance days. During a positive reinforcement day, each work unit completed by a subject incremented a group account. The account was divided evenly among the three participants at the conclusion of the study. During a negative reinforcement day, no money was earned, and the group was assigned a work unit criterion that, if completed, prevented a reduction in accumulated earnings. During negative reinforcement days, subjects made aggressive verbal responses, which differed in magnitude among the four groups. These differences were evident in several distinct behavioral measures. Performances on components of the work unit were not demonstrably affected by the reinforcement schedules in effect, although during the avoidance condition one subject stopped working and another subject's productivity decline

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-157

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Five children, ranging in age from 3½ years to 5½ years, were taught various four‐response chains using conditioned reinforcement. Experiment 1 investigated the effects of presenting “instruction” stimuli — a sequence of lights over the correct response buttons — to assess their role in facilitating the acquisition of a chain of responses. Without the “instruction” stimuli, children made many errors before responses were brought under the control of the programmed contingencies. When confronted with the same contingencies later in the day, these subjects made fewer errors. In contrast, in the presence of the “instruction” stimuli, subjects made virtually no errors. However, when the “instruction” stimuli were discontinued in the subsequent session, all 5 subjects made errors. In Experiment 2, the subjects were taught to verbalize the contingencies during the phase without the “instruction” stimuli. This resulted in errorless performance during the subsequent exposure to the same procedure, but errors nevertheless occurred again during reexposure to the procedure with the “inst

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-175

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

A classic experiment by Hefferline, Keenan, and Harford (1959) showed that small thumb‐twitches, imperceptible to the subject, can be controlled by the consequences of terminating and/or postponing aversive noise. These findings were further investigated in three experiments reported here. Experiment 1 replicated the original study. Experiment 2 was a control study in which stimulus changes were presented as in Experiment 1, but independently of the responses. Under these conditions the response rate varied over a large range with no systematic relation to experimental events. The increments in response rate reported by Hefferline et al. were within the present range of variation, suggesting that conditioning in the earlier study may have reflected a consistency in the direction of change rather than an increase in rate beyond the baseline range. In the present experiment, however, the rate increase was absolute. In Experiment 3, analog rather than binary changes in stimulus conditions were used as reinforcement. Under these conditions, the rates of subjects whose responses were conditioned fell from 78% (in the previous experiment) to 31

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-185

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Previous studies have identified a reliable relation between the quantity of food ingested and ruminating in profoundly retarded individuals and have established some parametric characteristics of this relation. The present study investigated three different properties of food that may influence this relation. Experiment 1 examined the role of stomach distention produced by including in the subject's diet wheat bran in amounts equivalent to and exceeding the calculated amount of crude fiber in the starch‐satiation diet reported by Rast, Johnston, Drum, and Conrin (1981) and Rast, Johnston, and Drum (1984). There was a decrease in ruminating, although this decrease was smaller and more gradual than in the starch‐satiation condition. Experiment 2 showed that increasing calories without increasing food volume resulted in a gradual and moderate decrease in ruminating. Experiment 3 replicated and extended the first two experiments by varying both caloric intake and stomach distention as well as oropharyngeal and esophageal stimulation in a different sequence of conditions. All variables exerted some control over responding. However, the large and immediate effects of the starch‐satiation procedure occurred only when subjects were permitted to consume unlimited quant

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-195

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Distributions of reinforcers between two components of multiple variable‐interval schedules were varied over a number of conditions. Sensitivity to reinforcement, measured by the exponent of the power function relating ratios of responses in the two components to ratios of reinforcers obtained in the components, did not differ between conditions with 15‐s or 60‐s component durations. The failure to demonstrate the “short‐component effect,” where sensitivity is high for short components, was consistent with reanalysis of previous data. With 60‐s components, sensitivity to reinforcement decreased systematically with time since component alternation, and was higher in the first 15‐s subinterval of the 60‐s component than for the component whose total duration was 15 s. Varying component duration and sampling behavior at different times since component transition may not be equivalent ways of examining the effects of average temporal distance b

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-207

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The spatiotemporal patterns of behavior exhibited by two pigeons during a variable‐interval 15‐second schedule of food reinforcement, a variable‐interval 5‐minute schedule, and then extinction of key pecking were recorded using an apparatus that continuously tracked the position of the bird in the experimental chamber. The variable‐interval 15‐second schedule produced a close‐to‐key pattern between reinforcements with two types of regular excursions from the region of the key frequently occurring after reinforcement. Subsequent exposure to the variable‐interval 5‐minute schedule produced more extended and extremely regular patterns between responses. Reinstatement of the variable‐interval 15‐second schedule reestablished the close‐to‐key pattern with regular excursions frequently occurring after reinforcement. During extinction the spatiotemporal patterns that had developed during the variable‐interval 5‐minute schedule reappeared and gradually dissipated. These patterns may have been a

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-217

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Two experiments examined pigeons' response rates during short trials signaled by stimuli closely spaced along a wavelength continuum. In Experiment 1 separate halves of the continuum were correlated with different reinforcement schedules. In Experiment 2, the middle stimulus was accompanied by a lower probability of reinforcement than were the remaining wavelengths. Both procedures resulted in dimensional contrast “shoulders,” seen as relatively enhanced or depressed response rates in the presence of stimuli between the extreme of the continuum and the border separating the positive and negative stimuli. Sequential analyses addressed possible contributions of the following interactions: (a) local contrast, seen when rate during a given schedule depends on the schedule in the just‐preceding trial; (b) modification of local contrast by the similarity of the signaling stimuli (P. Blough, 1983); and (c) schedule‐independent rate contrast, seen when rate in a given trial depends on the rate controlled by the stimulus that accompanied the just‐preceding trial (Malone&Rowe, 1981). Dimensional contrast functions were similar when isolated according to the schedule, to the similarity of the signaling stimulus, and to the response rate of the just‐preceding trial. The interactions noted above do not appear to make important contributions to

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-233

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

This paper is a selective review of research that addresses the validity of two interpretations of stimulus generalization. One interpretation, referred to as the descriptive stimulus‐control interpretation, proposes that during stimulus generalization a continuous relation exists between stimulus and response dimensions. The other interpretation, referred to as the quantal interpretation, proposes that a stimulus‐response relation functions as a unit that may or may not occur. From the latter viewpoint, the continuity typically obtained during generalization tests is deemed to be artifactual and to result from averaging across multiple controlling stimulus‐response relations. Studies examining the contribution of these multiple relations to generalization gradients are reviewed. With few exceptions, the quantal interpretation appears to better characterize the results of these studies. Implications for peak shift, selection of analytical level, and identification of the behavioral unit are discussed, as well as factors that may determine the acceptability of the quantal interpret

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-245

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-271

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY