摘要:

Three previous studies have failed to demonstrate conditioning in infants using a 3‐s delay of reinforcement. The effects of a delayed reinforcement schedule on vocalization rates therefore were explored in a single‐subject repeated‐reversal experimental design for 3 4‐ to 6‐month‐old normally developing infants. Each infant received delayed social reinforcement from his or her parent for vocalizing. The comparison condition was a schedule of differential reinforcement of behavior other than vocalizations to control for elicitation by social stimulation. An operant level of infant vocalizations was the initial condition, after which the differential reinforcement schedule was implemented in an across‐subjects multiple baseline design. Infants' vocalization rates increased above levels measured during differential reinforcement following onset of the delayed reinforcement condition. Also, vocalization rates decreased during differential reinforcement compared to operant levels. The successful use of delayed reinforcement schedules with infants in this study, as opposed to others, is discussed in terms of procedural differenc

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-1

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Conditional “if‐then” relations between drug (interoceptive) stimuli and visual (exteroceptive) stimuli were taught to 4 normal humans. Interoceptive stimuli were the effects produced by 0.32 mg/70 kg triazolam (a prototypical benzodiazepine) and placebo (lactose‐filled capsules); exteroceptive stimuli were black symbols on white flash cards. Following the training of the prerequisite conditional relations, tests of emergent relations were conducted between exteroceptive stimuli and between interoceptive and exteroceptive stimuli. Equivalence relations emerged immediately without explicit training for all 4 subjects. Accuracy of responding during the interoceptive‐exteroceptive equivalence tests and subjects' self‐reports showed consistent discrimination between the drug effects of triazolam and placebo. Finally, a generalization test assessed whether a novel visual stimulus presented in the context of the placebo (i.e., no drug) would generalize to visual stimuli belonging to the placebo stimulus class. All 3 subjects who completed this test reliably chose the visual stimuli belonging to the placebo class and not the visual stimuli belonging to the triazolam stimulus class. The development of equivalence relations between interoceptive and exteroceptive stimuli demonstrates that private and public stimulus events can emerge as members of the same equivalence class. Theoretical and clinical implications ar

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-9

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Rates of responding changed systematically across sessions for rats pressing levers and keys and for pigeons pressing treadles and pecking keys. A bitonic function in which response rates increased and then decreased across sessions was the most common finding, although an increase in responding also occurred alone. The change in response rate was usually large. The function relating responding to time in session had the following general characteristics: It appeared early in training, and further experience moved and reduced its peak; it was flatter for longer sessions; and it was flatter, more symmetrical, and peaked later for lower than for higher rates of reinforcement. Factors related to reinforcement exerted more control over the location of the peak rate of responding and the steepness of the decline in response rates than did factors related to responding. These within‐session changes in response rates have fundamental theoretical and methodological implication

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-19

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Pigeons chose between two fixed‐interval schedules of food reinforcement. A single peck on one of two lighted keys started the fixed‐interval schedule correlated with that key. The schedule had to be completed before the next choice opportunity. The durations of the fixed intervals were varied over conditions from 15 s to 40 s. To maximize the rate of reinforcement, the pigeons had to choose exclusively the shorter of the two schedules. Nevertheless, choice was not all‐or‐none. Instead, relative choice, and the rates of producing the fixed intervals, varied in a graded fashion with the disparity between the two schedules. Choice ratios under this procedure (single response to choose) were highly sensitive to the ratios of the fixed‐interval

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-37

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Pigeons trained on cyclic‐interval schedules adjust their postfood pause from interval to interval within each experimental session. But on regular fixed‐interval schedules, many sessions at a given parameter value are usually necessary before the typical fixed‐interval “scallop” appears. In the first case, temporal control appears to act from one interfood interval to the next; in the second, it appears to act over hundreds of interfood intervals. The present experiments look at the intermediate case: daily variation in schedule parameters. In Experiments 1 and 2 we show that pauses proportional to interfood interval develop on short‐valued response‐initiated‐delay schedules when parameters are changed daily, that additional experience under this regimen leads to little further improvement, and that pauses usually change as soon as the schedule parameter is changed. Experiment 3 demonstrates identical waiting behavior on fixed‐interval and response‐initiated‐delay schedules when the food delays are short (<20 s) and conditions are changed daily. In Experiment 4 we show that daily intercalation prevents temporal control when interfood intervals are longer (25 to 60 s). The results of Experiment 5 suggest that downshifts in interfood interval produce more rapid waiting‐time adjustments than upshifts. These and other results suggest that the effects of short interfood intervals seem to be more persistent than

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-47

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

College undergraduates were given repeated opportunities to choose between a fixed‐ratio and a progressive‐ratio schedule of reinforcement. Completions of a progressive‐ratio schedule produced points (exchangeable for money) and incremented that response requirement by 20 responses with each consecutive choice. In the reset condition, completion of a fixed ratio produced the same number of points and also reset the progressive ratio back to its initial value. In the no‐reset condition, the progressive ratio continued to increase by increments of 20 throughout the session with each successive selection of this schedule, irrespective of fixed‐ratio choices. Subjects' schedule choices were sensitive to parametric manipulations of the size of the fixed‐ratio schedule and were consistent with predictions made on the basis of minimizing the number of responses emitted per point earned, which is a principle of most optimality theories. Also, the present results suggest that if data from human performances are to be compared with results for other species, humans should be exposed to schedules of reinforcement for long periods of time, as is commonly done with nonhum

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-67

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The acute effects of cocaine hydrochloride (4 to 96 mg/70 kg) and alcohol (0 to 1.0 g/kg), administered alone and in combination, were assessed in two experiments with human volunteers responding under a multiple schedule of repeated acquisition and performance of response chains. Subjects were intermittent users of cocaine and regular drinkers who were not cocaine or alcohol dependent. Alcohol was mixed with orange juice and ingested in six drinks within 30 min; cocaine was administered intranasally 45 min after completion of drinking. In each component of the multiple schedule, subjects completed response sequences using three keys of a numeric keypad. In the acquisition component, a new sequence was learned each session. In the performance component, the response sequence always remained the same. Results were consistent in both experiments, despite variations in the order in which the drugs were tested alone and in combination. Alcohol administered alone increased overall percentage of errors and decreased rates of responding in the acquisition component, whereas responding in the performance component generally was unaffected. Cocaine administered alone decreased rates of responding but did not affect accuracy of responding in the acquisition component, and enhanced accuracy of responding without affecting rates of responding in the performance component. The combined doses of cocaine and alcohol attenuated the effects observed with alcohol and cocaine alone. These results suggest that, under the conditions investigated in this study, (a) alcohol produces greater behavioral disruption than cocaine or cocaine‐alcohol combinations, (b) cocaine and alcohol each attenuate effects of the other, and (c) such attenuation is most pronounced for cocaine attenuating the disruptive effects of alcoho

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-87

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

College students responded under a multiple differential‐reinforcement‐of‐low‐rate 5‐s fixed‐ratio 8 schedule, with components alternating every 2 min. After 40 programmed minutes of acquisition and 12 min of maintenance, without notice, both schedules changed to extinction for 28 min. During acquisition, between alternations of the multiple schedule, some subjects were asked to develop rules describing the schedule contingencies. Other subjects were given these same rules between alternations, and a third group neither received nor were asked to develop rules. By the end of the acquisition phase, self‐generated‐rule subjects were more likely to show schedule‐typical behavior than were subjects not asked to generate rules. The behavior of those given rules was similar to those asked to generate rules at the end of acquisition, but yoked‐rule subjects acquired schedule‐typical behavior at a quicker rate. By the end of extinction, during the period corresponding to the previous fixed‐ratio interval, all no‐rule subjects who had earned points during acquisition and maintenance were responding at a rate of less than 30 responses per minute. Only 3 of the 9 self‐generated‐rule subjects and 2 of the 5 yoked‐rule subjects were similarly responding at this low rate. Results suggest that asking subjects to develop self‐rules facilitates acquisition, but can retard extinction. Results also suggest that self‐generated rules f

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-107

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The development of functional and equivalence classes was studied in four high‐functioning, preschool‐aged autistic children. Initially, all subjects failed to demonstrate match‐to‐sample relations indicative of stimulus equivalence among two three‐member classes of visual stimuli. Then, 2 subjects showed emergence of those relations after they were taught to assign the same name to all members in each class. Next, subjects were taught names for new stimuli outside the match‐to‐sample format. On subsequent match‐to‐sample tests, 2 subjects demonstrated untrained conditional relations among the stimuli given a common name. New, unnamed stimuli were then related via match‐to‐sample training to stimuli from sets of named stimuli. Tests for emergent conditional relations between the new unnamed stimuli and the named stimuli yielded positive results for 1 subject and somewhat mixed results for 3 subjects. Finally, without naming, 2 subjects developed stimulus equivalence among two new three‐member classes of visual stimuli. These data suggest that naming may remediate failures to develop untrained conditional relations, some of which are indicative

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-123

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Pigeons were trained in a delayed matching‐to‐sample procedure in which the sample stimuli consisted of a compound of color (red or green) and spatial location (left or right). A postsample cue (houselight on or off) signaled whether color matching or location matching would be required following the delay. In Experiment 1, the reduction in performance on probe trials (in which the houselight condition was reversed relative to that on regular trials) was greater for location matching than for color matching. The birds showed overt mediational behavior during the delays on location‐matching trials. On color‐matching trials, the birds exhibited behavior during delays that might have interfered with that mediational behavior. In Experiment 2, the houselight condition was changed shortly before presentation of the comparison stimuli on probe trials. Accuracy of location matching was reduced when the cue initially signaled color matching and was then changed to signal location matching, whereas matching accuracy was not reduced by a change in the opposite direction. Accuracy of color matching was reduced by a change in illumination level from dark to light, regardless of type of the relevant dimension signaled by houselight illumination. Discussion of these findings focuses on the variables critical to establishment of an effective cue to

ISSN:0022-5002    

DOI:10.1901/jeab.1992.58-135

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY