摘要:

Five younger (18 to 23 yrs) and five older (65 to 73 yrs) men were exposed to a series of immediate and delayed (0 to 15 seconds) matching‐to‐sample problems. Presentation of the pairs of delayed comparison stimuli was either signaled or unsignaled, and the sample contained either 1, 2, or 3 elements, one of which appeared as the positive stimulus. During initial sessions, unlimited time was available to respond. Subsequently, correct responses were reinforced only if they occurred within a specified time limit. A general finding was slower responding with increased delay and with increased number of sample elements. These effects were reduced when the comparison stimuli were signaled and when time limits were in effect. Errors increased as a function of the manipulations of sample complexity and time limits, but did not change systematically when the delay between sample and comparison stimuli was varied. Although the younger men generally responded more quickly than the older ones, men of both ages showed increased speeds when limits were placed on response time, and these changes were maintained when the temporal contingencies were remo

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-1

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Performance of pigeons in delayed matching‐to‐sample procedures was measured in terms of an index of discriminability derived from the difference between logarithms of ratios of choice responses to comparison stimuli following the different sample stimuli. Forgetting functions that plotted discriminability as a function of delay‐interval duration were well described by a simple negative exponential function with two parameters, one describing initial discriminability of sample stimuli at zero delay (logd0) and the other describing rate of decrement in discriminability with increasing delay‐interval duration (b). With the difference between wavelength values of the comparison stimuli held constant, a large difference between wavelengths of the sample stimuli resulted in a higher logd0value than that for a small difference between sample stimuli, without changing the rate of decrement in discriminability,b. An increase in the fixed‐ratio requirement for sample‐key responding produced an increase in logd0without affectingb, and interpolation of ambient illumination in the delay interval increasedbwithout influencing logd0. Both parameters changed when intertrial‐interval duration was varied. The result of variation in the point of interpolation of ambient illumination in the delay interval indicated that levels of discriminability at longer delays were independent of discriminability levels at earlier delays, consistent with the properties of the exponential function. Functions relating performance to delay‐interval duration were suggested to have two characteristics: discriminability of the sample stimuli in the absence of a delay between the stimuli and the behavior they occasion, and rate of attenuation in discriminability with increasing delay‐

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-15

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

In Experiment 1 six monkeys were tested with discriminative relations that were backward relative to their training in a 0‐second conditional (“symbolic”) matching procedure. Although there was some indication of backward associations, the evidence was generally weak, and statistical evaluations did not reach conventional significance levels. Unlike children, who show backward associations to the point of symmetry, monkeys and pigeons display at best only weak and transient backward associations. In Experiment 2 associative transitivity was assessed across two sets of conditional matching tasks. All four monkeys tested demonstrated strong transitivity. In contrast, in Experiment 3 there was no evidence of transitivity in three pigeons tested under conditions closely comparable to those of Experiment 2. These results may identify some key features of interspecies differences and contribute to analyses of serial learning in an

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-35

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Pigeons were trained to perform simultaneous, two‐color matching to sample under a multiple fixed‐ratio fixed‐interval schedule of food presentation. The sequence terminating with a peck on the matching key (a “match”) was treated as a unit, analogous to a single key peck in conventional schedules. Except for intermittent reinforcement of matches, no consequent stimulus distinguished matches from mismatches (sequences terminating with pecks on the nonmatching key). The pattern of matches during nondrug sessions resembled that of simpler operants maintained by similar schedules. Matches increased in rate toward the end of both components; mismatch rates increased more slowly. Imipramine increased the rate of mismatches, disrupted schedule patterning, and lowered accuracy in a dose‐dependent fashion. Chlorpromazine lowered the overall rate of matches but affected schedule patterns and accuracy less than imipramine. The types of errors during drug sessions were not systematically related to the types of errors that appeared during nondrug sessions. Stimulus control was evaluated for each of the four possible color configurations and was found to be by the entire configuration of colors, not simply by the color of

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-49

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Pigeons' not pecking or pecking constituted choice between a delayed, large reinforcer and an immediate, small reinforcer (self‐control) and at other times between a delayed reinforcer and no reinforcer (omission). Both a tone and a keylight were tested as choice signals, and the delayed reinforcer was either response independent or response dependent. Pigeons pecked during the choice signals on over 95% of the trials in the self‐control procedure, and pecked during the choice signals on over 75% of the trials in the omission procedure. Consistent pecking was observed with either the tone or the keylight as a choice signal, with the exception that a tone paired with a response‐independent delayed reinforcer did not maintain pecking in the omission procedure. Pigeons pecked during more choice signals when delayed reinforcers were response dependent than when the delayed reinforcers were response independent. These results indicate that Pavlovian conditioning influences self‐control experiments, especially in single‐key p

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-69

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Four pigeons were trained on concurrent variable‐interval schedules programmed on a center response key, with access to those schedules controlled by responses on left or right side keys. Two procedures were used. In one, the pigeon was given limited access, in that each side‐key response produced 3‐s access to a center‐key schedule, and in the other procedure, access was unlimited. Data were analyzed using the generalized matching law. Comparison of sensitivities to reinforcement of interchangeover time for both procedures showed them to be of similar magnitude. Response sensitivities were also similar in magnitude for both procedures. From the limited‐access procedure a second time measure that was available, switched‐in time, was relatively uncontaminated by time spent emitting behavior other than key pecking. Sensitivities to reinforcement for the switched‐in time measure were always smaller than interchangeover‐time sensitivities for either procedure, and were approximately equal to response sensitivities for the limited‐access procedure. Two other access times (5 and 7.5 s) were studied to validate the choice of 3 s as the main access time. These results indicate that when time spent emitting other behavior is excluded from interchangeover time, time and response sensitivities will be ap

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-79

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Five pigeons were trained under concurrent‐chain schedules in which a pair of independent, concurrent variable‐interval 60‐s schedules were presented in the initial link and either both variable‐interval or both fixed‐interval schedules were presented in the terminal link. Except for the baseline, one of the terminal‐link schedules was always a two‐component chained schedule and the other was either a simple or a tandem schedule of equal mean interreinforcement interval. The values of the fixed‐interval schedules were either 15 s or 60 s; that of the variable‐interval schedules was always 60 s. A 1.5‐s changeover delay operated during the initial link in some conditions. The pigeons preferred a simple or a tandem schedule to a chain. For the fixed‐interval schedules, this preference was greater when the fixed interval was 60 s than when it was 15 s. For the variable‐interval schedules, the preferences were less pronounced and occurred only when the changeover delay was in effect. For a given type of schedule and interreinforcement interval, similar preferences were obtained whether the nonchained schedule was a tandem or simple schedule. The changeover delay generally inflated preference and lowered the changeover rate, especially when the terminal‐link schedules were either short (15 s) or aperiodic (variable‐interval). The results were consistent with the notion that segmenting the interreinforcement interval of a schedule into a chain l

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-89

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-102

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Six pigeons were trained on multiple schedules whose components were concurrent variable‐interval extinction and concurrent extinction variable‐interval schedules. In Experiments 1a and 1b the stimuli signaling the components were two different light intensities, and in Experiments 2a and 2b they were two identical intensities. The components of the multiple schedule changed probabilistically after each reinforcer. In Experiments 1a and 2a, the probability of presenting the components was varied over five conditions and a replication. In Experiments 1b and 2b, the component probability was .5 and the component reinforcer rates were varied systematically over five conditions and a replication. The data, analyzed according to the Davison‐Tustin behavioral detection model, confirmed that the discriminability of the stimuli signaling the components was high when the stimuli were different, and low when the stimuli were the same. Discriminability, measured by logd, was unaffected by component probability variation and by component reinforcerrate variation. When discriminability was high, bias, or the response allocation between the two keys, was more strongly affected by variation of reinforcer rate within components than by variation of component probability, but the reverse was found when discriminability was low. The results suggest that free‐operant detection performance is controlled by the rates of reinforcers in periods of time in which stimuli signal differential contingencies. These periods comprise the components when the component stimuli are discriminable, and comprise the total session when the components are indiscriminable. An extension of the Davison‐Tustin behavioral detection model that incorporates these results is

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-103

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Studies of pigeon behavior in which magazine‐cycle duration is varied suggest that many researchers assume that feeders of different designs dispense food at roughly the same rate. However, Epstein (1981) showed that, with a commonly used feeder, the amount of grain a pigeon consumes is a negatively accelerated function of magazine‐cycle duration. The present experiment shows that, with a different commonly used feeder, amount consumed is roughly a linear function of magazine‐cycle duration. At a duration of 60 seconds, the second feeder dispenses roughly 10 times as much food as the first. Thus, reports of studies in which magazine‐cycle duration is varied should identify the design of the feeder employed, and in some cases, authors should consider determining the feeding functions for those

ISSN:0022-5002    

DOI:10.1901/jeab.1985.44-121

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY