ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-123

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-127

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

In a residential research ward coffee drinking was studied in 9 volunteer human subjects with histories of heavy coffee drinking. A series of five experiments was undertaken to characterize adlibitum coffee consumption and to investigate the effects of manipulating coffee concentration, caffeine dose per cup, and caffeine preloads prior to coffee drinking. Manipulations were double‐blind and scheduled in randomized sequences across days. When cups of coffee were freely available, coffee drinking tended to be rather regularly spaced during the day with intercup intervals becoming progressively longer throughout the day; experimental manipulations showed that this lengthening of intercup intervals was not due to accumulating caffeine levels. Number of cups of coffee consumed was an inverted U‐shaped function of both coffee concentration and caffeine dose per cup; however, coffee‐concentration and dose‐per‐cup manipulations did not produce similar effects on other measures of coffee drinking (intercup interval, time to drink a cup, within‐day distribution of cups). Caffeine preload produced dose‐related decreases in number of cups consumed. As a whole, these experiments provide some limited evidence for both the suppressive and the reinforcing effects of caffeine on coffee consumption. Examination of total daily coffee and caffeine intake across experiments, however, provides no evidence for precise regulation (i.e., titration) of coffee or ca

ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-133

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

By means of a discrete‐trial simultaneous discrimination procedure, pigeons were trained to respond differentially to visual arrays that were identical except that one of them contained a circle displaced in depth when viewed stereoscopically. Performance was severely disrupted when one eye was occluded. The monocular deficit was peculiar to the depth task, inasmuch as no such decrement was seen on a pattern discrimination. The results imply that presence of the displaced circle was discriminated on the basis of a binocular cue. It was also found that pigeons could discriminate the direction of the displacement. Discrimination of depth was independent of the global form and still occurred when elements of the array were randomly displaced in depth. Performance was not disrupted when the absolute convergence angle of the depth stimulus was changed. The cue that consistently accounted for the behavior seen was the detection of the relative angles of convergence—that is, the retinal disparity of the two planes in depth. Thus, despite the lateral position of the eyes of the pigeon, a small binocular field mediates the binocular discrimination of near objects in de

ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-149

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

In a conditional discrimination, reinforcement of pigeons' responses to pairs of simultaneously presented wavelength stimuli depended on the orientation of white lines superimposed on the wavelengths. Over different conditions in Experiment 1, three wavelength differences were combined with two differences between successively presented line orientations. Measures of stimulus discriminability increased with increases in the difference between both orientation and wavelength stimuli. Conditional‐discrimination performance was thus conjointly determined by stimulus disparity in the successive and simultaneous discriminations. In Experiment 2, ratios of rates of reinforcement contingent upon the two categories of correct responses were varied over several conditions for difficult and easy discriminations. Ratios of responses to wavelength pairs were sensitive to variations in the reinforcement ratio to a greater extent for the more difficult orientation discrimination than for the easier orientation discrimination. Performance in the conditional discrimination was therefore determined by the interacting effects of stimulus disparity and the relative rates of reinforcement contingent upon the two correct choices. It was concluded that the effect of temporally distant reinforcement on behavior in a prevailing schedule component is attenuated to an extent that depends on similarity of stimuli that delineate the successive component

ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-161

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Seven albino rats were exposed to a multiple schedule of reinforcement in which the two components (fixed interval and extinction) alternated such that a presentation of the extinction component followed each fixed‐interval reinforcement. In baseline sessions, the duration of the extinction component was constant and always one‐third of the fixed‐interval value. Probe sessions contained a probe segment in which the duration of the extinction component was increased; the response rate in fixed‐interval components during the probe segment was compared with the response rate in the segments preceding and following the probe. The effect of increasing the duration of the extinction component was studied under three values of fixed interval: 30 s, 120 s, and 18 s, in three successive conditions. Response rate within fixed intervals was a direct function of duration of the extinction component. Pausing at the beginning of the fixed interval decreased as extinction duration increased. These effects were larger and more consistent for the shorter fixed‐interval values (18 s and 30 s). These results indicate a functional relation between relative component duration and responding. For the component providing more frequent reinforcement, this could be stated as an inverse relationship between relative component duration and response rate. This relation is similar to findings regarding the ratio of trial and intertrial duration in Pavlovian conditioning procedures, and suggests that behavioral contrast may be related to Pavlovian contingencies underlying the multiple

ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-175

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Squirrel monkeys' lever pressing produced by response‐independent shock was measured before, and for an extended period following, exposure to a shock‐avoidance procedure. Following avoidance training, the frequency of responding increased by multiples of 10 to 50 across subjects and evidence little or no decrement for up to 6 months of postreinforcement testing. Manual responding produced by intense environmental stimulation may be substantially strengthened by a brief history of reinforcement, such that it is sustained over long periods without reinforcem

ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-189

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Effects of chlorpromazine (1 to 100 mg/kg) were assessed on two pigeons' responding under various modifications of a multiple schedule of food delivery. During a fixed‐interval component, the first response after 5 min produced food; during the subsequent, fixed‐ratio component, the 30th response produced food. Modifications of the schedule entailed changes in stimulus conditions imposed during the fixed‐ratio component that did not systematically alter characteristics of performance under non‐drug conditions. In the first phase of the experiment, distinctive visual stimuli were correlated with each schedule component (conventional multiple schedule); chlorpromazine produced small decreases in fixed‐ratio responding (20% at 30 mg/kg). When each response during the fixed‐ratio component produced the stimulus correlated with the fixed‐interval schedule (fixed‐interval discriminative stimulus) for 1.2 s, effects of chlorpromazine were not different from those under the conventional multiple schedule. Chlorpromazine produced greater decreases in fixed‐ratio responding (55% at 30 mg/kg) when either the first response of each fixed ratio changed the stimulus correlated with the fixed‐ratio schedule to the fixed‐interval discriminative stimulus for the remainder of the fixed‐ratio component, or when the fixed‐interval discriminative stimulus was presented independently of responding according to a matched temporal sequence. When the fixed‐interval discriminative stimulus was present continuously during the fixed‐ratio component (mixed schedule), chlorpromazine produced even more substantial decreases in fixed‐ratio responding (greater than 80% at 30 mg/kg). Effects of chlorpromazine on fixed‐interval responding were also modified by the schedules of fixed‐interval discriminative stimulus presentation. The effects of chlorpromazine were a joint function of the stimuli prevailing during the multiple schedule and the degree to which

ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-195

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A series of doses (0.5 to 2.0 mg/kg) ofd‐amphetamine was administered to rats whose lever pressing was maintained by fixed‐interval 30‐s, 60‐s, or 120‐s schedules of reinforcement by sucrose delivery. Under both saline andd‐amphetamine conditions, molecular features of responding were reliably described in terms of the distribution of postreinforcement pauses and local response rate following the onset of responding. Postreinforcement pause always varied from interval to interval but, on average, shortened under the drug. Local response rate (response rate exclusive of pause time) tended to decrease under the drug, and where acceleration occurred within runs of responses, it was reduced by the drug. All of these effects were dose‐related. These findings suggest that fixed‐interval behavior can be analyzed effectively at a molecular level, and that the effects ofd‐amphetamine are best described as disruption of tempor

ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-207

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Squirrel monkeys were trained to respond under a multiple fixed‐interval, fixed‐interval schedule in which the first response after 5 min terminated a visual stimulus in the presence of which electric shocks could occur. During one component of the schedule, correlated with one color of stimulus lights, every 30th response also produced electric shock; responding was suppressed during this component to approximately 10 to 12% of that occurring in the alternate component in which responding was not punished. In contrast to previous research, morphine (0.03 to 1.0 mg/kg) increased punished responding. Unpunished responding, however, was either not affected or decreased at doses of morphine that increased punished responding. Increases in rate of punished responding also occurred when the single‐schedule punishment condition was studied alone in these animals. Subsequent experimentation, which systematically analyzed the development of the rate‐enhancing effects of morphine on punished responding, involved the study of drug effects in additional monkeys trained initially under a single‐schedule punishment condition. The effects of morphine on punished responding were studied before, after, and then during exposure to the multiple schedule that included a component in which responding was not punished. Increases in response rate with morphine did not occur until it was administered during exposure to the multiple schedule that included a component in which responding was not punished. As with the other monkeys, once the rate increases in punished responding occurred under the multiple schedule, these effects of morphine persisted, even when the multiple schedule was removed. These findings indicate that the behavioral effects of a drug can depend on the combined influence of that drug and the specific circumstances under which it is studied. Neither the behavioral experience alone nor exposure to the drug was sufficient to alter morphine's effects. Once this drug‐behavior interaction occurs, however, the behavioral effects of that drug can be changed su

ISSN:0022-5002    

DOI:10.1901/jeab.1986.45-221

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY