摘要:

Normally capable adults learned two‐choice identity matching of three‐digit numerals and arbitrary matching of physically dissimilar nonsense syllables. The stimuli were displayed on a computer terminal, and responses consisted of typing on the terminal's keyboard. In Experiment 1, every trial displayed a sample numeral, a comparison numeral, and three equal signs (===). The comparison stimulus was to be selected if it was identical with the sample; otherwise the equal sign was to be selected. This “single comparison” method was then used to show that arbitrary matching could be based upon either sample‐S+ or sample‐S– relations. In Experiment 2, a series of probe trials displayed a novel sample, a comparison stimulus from the arbitrary matching baseline, and ===. Subjects typically selected ===; they apparently were excluding the baseline comparison stimulus. Experiments 3 through 5 investigated which variables in training would lead to the selection of baseline comparison stimuli in response to novel samples. Behavior was usually unchanged when baseline training included relating comparison stimuli to as many as four different samples. Punishment contingencies were effective, but performance did not generalize unless those contingencies were applied in relation to more than one baseline compar

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-187

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Under various feedback conditions, 38 college undergraduates were asked to rearrange abstract graphic characters on a computer screen, placing them in arbitrarily designated “correct” sequences. Two sets of seven horizontally arrayed stimuli were used. In Experiment 1, subjects in Group 1 learned to arrange the first set under Selection Feedback in which a “+” appeared above each character after it was selected in the correct order and to arrange the second set under Order Feedback in which a correct response produced a copy of the character in its correct ordinal position at the top of the screen. For Group 2 the order of these conditions was reversed. In Experiment 2, for subjects in Group 3, correct responses produced neither of these types of feedback. Subjects in Group 4 received Order Feedback only until the first set was correctly ordered once. Order Feedback was more effective than Selection Feedback during initial acquisition of the first set but not during maintenance; no differences were found for the second set. Only 2 of 9 subjects successfully put the characters in correct sequential order under the No Feedback condition. When, in Experiment 2, Order Feedback was eliminated after the first correctly arranged sequence, the steady‐state criteria were met more slowly than in Exp

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-209

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Three reinforcement contingencies were compared with regard to performance differences and cost‐effectiveness (i.e., responses per unit reinforcer). Pairs of college students were studied under individual, cooperative, or competitive contingencies using a concurrent setting that included one of these three contingencies as one alternative and a lower paying individual contingency as the other alternative. With the individual and the cooperative contingencies, overall response rates were typically high; under competitive contingencies the overall response rates were substantially lower. Subjects responded at very high rates when competing, but chose not to compete most of the time. Competition and cooperation produced the most cost‐effective responding, assessed as the number of responses made per $.01 of reinforcer. High overall rates of competitive responding were obtained when the contests were longer and the lower paying alternative contingency was not availa

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-221

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

In a concurrent‐chains procedure, pigeons' responses on left and right keys were followed by reinforcers of different durations at different delays following the choice responses. Three pairs of reinforcer delays were arranged in each session, and reinforcer durations were varied over conditions. In Experiment 1 reinforcer delays were unequal, and in Experiment 2 reinforcer delays were equal. In Experiment 1 preference reversal was demonstrated in that an immediate short reinforcer was chosen more frequently than a longer reinforcer delayed 6 s from the choice, whereas the longer reinforcer was chosen more frequently when delays to both reinforcers were lengthened. In both experiments, choice responding was more sensitive to variations in reinforcer duration at overall longer reinforcer delays than at overall shorter reinforcer delays, independently of whether fixed‐interval or variable‐interval schedules were arranged in the choice phase. We concluded that preference reversal results from a change in sensitivity of choice responding to ratios of reinforcer duration as the delays to both reinforcers are lengt

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-235

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

In a discrete‐trials procedure, pigeons chose between a fixed‐ratio 81 schedule and a progressive‐ratio schedule by making a single peck at the key correlated with one or the other of these schedules. The response requirement on the progressive‐ratio schedule began at 1 and increased by 10 each time the progressive‐ratio schedule was chosen. Each time the fixed‐ratio schedule was chosen, the requirement on the progressive‐ratio schedule was reset to 1 response. In conditions where there was no intertrial interval, subjects chose the progressive‐ratio schedule for an average of about five consecutive trials (during which the response requirement increased to 41), and then chose the fixed‐ratio schedule. This ratio was larger than that predicted by an optimality analysis that assumes that subjects respond in a pattern that minimizes the response‐reinforcer ratio or one that assumes that subjects respond in a pattern that maximizes the overall rate of reinforcement. In conditions with a 25‐s or 50‐s intertrial interval, subjects chose the progressive‐ratio schedule for an average of about eight consecutive trials before choosing the fixed‐ratio schedule. This change in performance with the addition of an intertrial interval was also not predicted by an optimality analysis. On the other hand, the results were consistent with the theory that choice is determined by the delays to the reinforcers delivered on the present tri

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-251

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

In Experiment 1, 3 rats chose between two simultaneously operating variable‐interval schedules, one of which provided saccharin water and the other, food. In five conditions, the absolute (and equal) reinforcement rates provided by the pair of equal‐valued schedules were manipulated in the range of 36 to 240 per hour. Experiment 2 was identical to Experiment 1 except that these schedules operated successively, arranged by requiring the rat to stand on the side of the chamber correlated with each schedule. Food/saccharin choice ratios were inversely related to reinforcement rate in both experiments, although this effect was stronger in Experiment 2. When delivery rates were high, preference for food over saccharin often reversed as the session progressed. The results were interpretable in terms of economic accounts of choice (e.g., the minimum‐needs hypothesis), as well as in terms of traditional psychological accounts (e.g., matching th

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-263

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

In Experiment 1 (within subjects) and Experiment 2 (between subjects) it was shown that the sequential training of pigeons on a color discrimination and then on its reversal, each in a different floor‐tilt/texture context, failed to produce conditional control of discriminative performance by those contexts. Daily alternation between the two problems (with correlated contexts) was successful, however. In each of these experiments conditional control was better reflected in generalization test performance in extinction than during sessions of training with reinforcemen

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-277

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

As a control for the effects of session duration and hunger on the relation between food magnitude and induced drinking, four food‐deprived rats were exposed to a variable‐time 50‐s schedule of food delivery in which the size of each food delivery varied randomly within sessions. Food‐related behavior and schedule‐induced drinking per opportunity were examined as functions of meal size and postfood time. All rats showed an inverted‐U‐shaped relation between drinking per opportunity and meal size. This relation was caused by variation in the percentage of intervals that contained drinking and by variation in the number of drinking bouts per interval, rather than by bout duration or by the amount of drinking within those intervals that actually contained drinking. Head‐in‐feeder time increased linearly with meal size. Schedule‐induced drinking was entrained by food delivery in 3 of 4 subjects; the entrainment was due to regulation of the starting time of each drinking bout rather than to regulati

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-289

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

In the present study, we examined how a reinforcement schedule history that generated high or low rates of responding influenced the effects of acute (Experiment 1) and chronic (Experiment 2) methadone administration. Initially, key‐peck responses of pigeons were maintained under a variable‐interval 90‐s schedule of food presentation, and a methadone dose‐response curve was determined with doses of 0.6, 1.2, and 2.4 mg/kg. The pigeons were then exposed, for at least 40 sessions, to either a fixed‐ratio 50 schedule or a differential‐reinforcement‐of‐low‐rate 10‐s schedule, or were given continued exposure to the variable‐interval schedule. The methadone dose—response curve was redetermined after all pigeons again were responding under the variable‐interval schedule. The effects of two different daily methadone doses (9.0 and 12.0 mg/kg/day) and withdrawal precipitated by naloxone also were assessed. Experience with a fixed‐ratio or differential reinforcement of low rate schedule did not result in significantly different response rates under the variable‐interval schedule and, in general, the acute effects of methadone did not have differential effects correlated with schedule history. However, for 2 of 4 subjects the rate‐decreasing effects of methadone on rates of key pecking were greater following a history of low‐rate responding, suggesting a possible interaction between schedule history and effects of methadone. Daily methadone administration under the variable‐interval schedule revealed that pigeons with experience under the differential reinforcement of low rate schedule developed more rapid and complete tolerance to the rate‐decreasing effects of methadone. Three of the 4 subjects in this group showed rate increases above drug‐free baselines during chronic methadone dosing. Pigeons with a history of fixed‐ratio responding also developed tolerance to the rate‐decreasing effects of methadone but without the subsequent rate increases seen by subjects with low‐rate histories. No subjects with variable‐interval histories showed complete recovery of drug‐free baselines, suggesting that interpolated training under other schedules may attenuate the rate‐altering effects of chronically administered drugs. Naloxone (1.0 mg/kg), administered during the chronic methadone phase, resulted in greater disruption of responding by pigeons with a history of low‐rate responding, as compared to subjects in the other two groups. These experiments reveal that although acute doses of methadone did not differentiate performances based on prior reinforcement schedule history, recovery of drug‐free baselines during chronic drug administration was more rapid and complete in subjects with low‐rate histories. It appears that reinforcement schedule histories can influence the behavioral effects of chronically administered methadone even when no current differences in baseline rates or in the

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-303

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The structure of equivalence classes can be completely described by four parameters: class size, number of nodes, the distribution of “singles” among nodes, and directionality of training. Class size refers to the number of stimuli in a class. Nodes are stimuli linked by training to at least two other stimuli. Singles are stimuli linked by training to only one other stimulus. The distribution of singles refers to the number of singles linked by training to each node. Directionality of training refers to the use of stimuli as samples and as comparison stimuli in training. These four parameters define the different ways in which the stimuli in a class can be organized, and thus provide a basis for systematically characterizing the properties of stimuli in a given equivalence class. The four parameters can also be used to account for the development of individual differences that are commonly characterized in terms of “understanding” and connotative meaning.Methods are described for generating all possible combinations of parameter values, and a formula is introduced which specifies all of the parameter values for an equivalence class. Its utility for interrelating experimental procedures is demonstrated by analyzing a number of representative experiments that have addressed equivalence‐class

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-317

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY