摘要:

Three experiments examined a discrimination training sequence that led to emergent simple discrimination in human subjects. The experiments differed primarily in their subject populations. Normally capable adults served in the first experiment, preschool children in the second, and mentally retarded adults in the third. In all experiments, subjects learned a simple simultaneous discrimination: When visual stimuli A1 and A2 were displayed together, reinforcers followed selections of A1, the S+, but not A2, the S‐. The subjects also learned a conditional discrimination taught with an arbitrary visual‐visual matching‐to‐sample procedure. Comparisons were two additional visual stimuli, B1 and B2, and samples were A1 and A2. Reinforcers followed selections of B1 in the presence of A1 and of B2 in the presence of A2. After the simple‐discrimination and conditional‐discrimination baselines had been acquired, B1 and B2 were displayed alone (without a sample) on probe trials. Subjects had never been taught explicitly how to respond to such displays. Nonetheless, they almost always selected B1, which was involved in a conditional relation with A1, the stimulus that served as S+ on the simple‐discrimination trials. This outcome suggested the formation of stimulus classes during conditional‐discrimination training. Through class formation, B1 and B2 had apparently acquired stimulus functions similar to those shown by A1 and A2 on simple‐discrimination trials, thereby leading to emergent selections of

ISSN:0022-5002    

DOI:10.1901/jeab.1988.50-1

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Few studies to date have examined time reallocation in naturalistic, multiresponse human repertoires when one or more responses are restricted. For this experiment, free‐operant baseline levels of six responses were measured for four autistic children. The high‐probability responses were made unavailable, one at a time, such that subjects had access to five, four, three, and two responses in successive restriction conditions. A return to the six‐response free‐operant baseline condition completed the experiment. Results were compared to predictions made by four time‐reallocation models. These results were described accurately only by the selective substitution model. Further analyses examined alternative explanations for the individual reallocation patterns obtained. An expanded selective substitution definition is proposed that may characterize orderly patterns observed in multiresponse repertoires under restriction conditions more accurately than the other existi

ISSN:0022-5002    

DOI:10.1901/jeab.1988.50-21

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

In Experiment 1, three pigeons' key pecking was maintained under a variable‐interval 60‐s schedule of food reinforcement. A 1‐s unsignaled nonresetting delay to reinforcement was then added. Rates decreased and stabilized at values below those observed under immediate‐reinforcement conditions. A brief stimulus change (key lit red for 0.5 s) was then arranged to follow immediately the peck that began the delay. Response rates quickly returned to baseline levels. Subsequently, rates near baseline levels were maintained with briefly signaled delays of 3 and 9 s. When a 27‐s briefly signaled delay was instituted, response rates decreased to low levels. In Experiment 2, four pigeons' responding was first maintained under a multiple variable‐interval 60‐s (green key) variable‐interval 60‐s (red key) schedule. Response rates in both components fell to low levels when a 3‐s unsignaled delay was added. In the first component delays were then briefly signaled in the same manner as Experiment 1, and in the second component they were signaled with a change in key color that remained until food was delivered. Response rates increased to near baseline levels in both components, and remained near baseline when the delays in both components were lengthened to 9 s. When delays were lengthened to 27 s, response rates fell to low levels in the briefly signaled delay component for three of four pigeons while remaining at or near baseline in the completely signaled delay component. In Experiment 3, low response rates under a 9‐s unsignaled delay to reinforcement (tandem variable‐interval 60 s fixed‐time 9 s) increased when the delay was briefly signaled. The role of the brief stimulus as conditioned reinforcement may be a function of its temporal relation to food, and thus may be related to the eliciting

ISSN:0022-5002    

DOI:10.1901/jeab.1988.50-33

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Rats' responses were reinforced on concurrent variable‐ratio variable‐ratio schedules in which responses on one lever incremented the ratio counter and responses on a second lever changed the schedule and correlated stimulus. The relative frequency of reinforcement was varied from .10 to .99. In one set of conditions, responding on the main lever incremented both ratio counters, but reinforcement required a response in the presence of the stimulus correlated with the ratio that had been completed. In a second set of conditions, responses on the main lever incremented only the ratio correlated with the stimulus that was currently present. When main‐lever responses incremented both ratio counters, subjects distributed responding and time in a manner consistent with the generalized matching law. When responses on the main lever incremented only the schedule currently in effect, the rats responded almost exclusively on the schedule producing the higher frequency of reinforcement. These results extend the applicability of the generalized matching law to dependent ratio sche

ISSN:0022-5002    

DOI:10.1901/jeab.1988.50-55

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Pigeons pecked a key under two‐component multiple variable‐ratio schedules that offered 8‐s or 2‐s access to grain. Phase 1 assessed the effects of differences in reinforcer magnitude on postreinforcement pausing, as a function of ratio size. In Phase 2, postreinforcement pausing and the first five interresponse times in each ratio were measured as a function of differences in reinforcer magnitude under equal variable‐ratio schedules consisting of different configurations of individual ratios. Rates were also calculated exclusive of postreinforcement pause times in both phases. The results from Phase 1 showed that as ratio size increased, the differences in pausing educed by unequal reinforcer magnitudes also increased. The results of Phase 2 showed that the effects of reinforcer magnitude on pausing and IRT durations were a function of schedule configuration. Under one configuration, in which the smallest ratio was a fixed‐ratio 1, pauses were unaffected by magnitude but the first five interresponse times were affected. Under the other configuration, in which the smallest ratio was a fixed‐ratio 7, pauses were affected by reinforcer magnitude but the first five interresponse times were not. The effect of each configuration seemed to be determined by the value of the smallest individual ratio. Rates calculated exclusive of postreinforcement pause times were, in general, directly related to reinforcer magnitude, and the relation was shown to be a function of schedule

ISSN:0022-5002    

DOI:10.1901/jeab.1988.50-65

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

During daily 3‐hr sessions, orally delivered pentobarbital solutions and water, or two separate pentobarbital solutions, were concurrently available to rhesus monkeys according to fixed‐ratio schedules of mouth contacts with a spout. First water, and then each of four “comparison‐concentration” pentobarbital solutions (0.0625, 0.25, 1, and 4 mg/mL), was successively available from one spout for a block of sessions under a fixed‐ratio‐64 (three monkeys) or fixed‐ratio‐16 (one monkey) schedule. Under an identically sized fixed‐ratio schedule, deliveries of a “standard‐concentration” pentobarbital solution were concurrently available from a second spout. The concentration of the standard solution remained unchanged throughout testing of the series of comparison solutions. Each of three pentobarbital concentrations (4, 1, and 0.25 mg/mL) in turn served as the standard concentration. Within each pair of concurrently available solutions, the higher drug concentration maintained more behavior than the lower concentration. Thus when monkeys were provided with concurrent access to different pentobarbital concentrations, relative reinforcing effects were directly related to drug concentration. Further, the amount of behavior maintained by a particular drug concentration was dependent on the concentration of the concurrently available drug solution. Thus, the relative effectiveness of a reinforcer in maintaining behavior is a function of both the reinforcer's magnitude and the availability of alternative reinf

ISSN:0022-5002    

DOI:10.1901/jeab.1988.50-75

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

The development of behavioral stereotypy is a common result of exposure to both response‐dependent and response‐independent reinforcement procedures. The generalized matching equation and two dynamic versions of that equation, which take into account the time differential between reinforcements and their effect on behavior, predict this outcome of many procedures involving reinforcement. Following from the assumption that distinct response topographies, distinct response sequences, or orientations to distinct stimuli can be treated in the equations as distinct classes of behavior, the equations predict that—at least for matching and undermatching—the behavior class that is most biased relative to other behavior classes of the same type will tend to predominate to the exclusion or near exclusion of those behavior

ISSN:0022-5002    

DOI:10.1901/jeab.1988.50-87

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1988.50-97

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY