摘要:

Rats obtained access to food twice each 24‐hour period. The first session was a work session in which food was available on a progressive‐ratio schedule. During the second session, which occurred between 1 and 23 hours after the work session, food was freely available up to a fixed total intake each 24 hours. The situation resembled elements of several real world circumstances, including the choice between continuing to forage in a rapidly depleting patch and waiting for a better patch, and between working now and receiving a guaranteed income later. The purpose of the experiment was to explore the time period over which future access to reward could affect current responding. Contrary to what might be expected from recent theorizing, anticipation of future food delayed by an hour or more after the start of the work session had no effect on current performance. Food intake was high and constant during work sessions except for a prefeeding effect that occurred when the free session closely preceded the next day's work session. Also, an increase in the difficulty of the work schedule increased the amount of work and the maximum price paid for food as if the work session were the only time food was available. The results indicate the importance of considering temporal limits in theories that require animals to integrate input over time to determine the allocation of resources among alternati

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-117

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Rumination is the chronic regurgitation, chewing, and reswallowing of previously ingested food. The study reported here, using a parametric design, examined the control of rumination by the quantity of food eaten at meals. The subjects were three profoundly retarded individuals who chronically emitted this behavior. The quantity of food by weight ingested daily was varied in 10‐oz steps in both ascending and descending series (data were collected only after breakfasts and lunches). Ruminating decreased when food quantity increased and increased when food quantity decreased. In addition, there was a similar inverse interaction between breakfast food quantity and post‐lunch ruminating. The data showed relatively rapid transitions in both frequency and duration at each meal size for all subjects. The data establish a clear functional relation between the quantity of food ingested and ruminat

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-125

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Six pigeons were trained to reproduce two‐event sequences in an experiment that employed a discrete‐trial procedure that required subjects to peck one of four possible sample sequences (left‐left, left‐right, right‐right, right‐left) signaled on a given trial by the successive illumination of response keys. Following a retention interval (0.1 to 30 seconds), a reinforcer was delivered if a subject reproduced the prior sample sequence during a test condition in which both left and right keys were illuminated. The pigeons readily reproduced the orders in which they had just seen and pecked two illuminated keys. Reproduction accuracy declined as the retention interval was increased. Homogeneous sequences (left‐left, right‐right) were reproduced with greater accuracy than heteroge

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-135

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

In previous studies of delayed reinforcement, response rate has been found to vary inversely with the response‐reinforcer interval. However, in all of these studies the independent variable, response‐reinforcer time, was confounded with the number of reinforcers presented in a fixed period of time (reinforcer frequency). In the present study, the frequency of available reinforcers was held constant, while temporal separation between response and reinforcer was independently manipulated. A repeating time cycle, T, was divided into two alternating time periods,tDandt▴. The first response intDwas reinforced at the end of the prevailing T cycle and extinction prevailed int▴. Two placements fortDwere defined, an earlytDplacement in whichtDprecedest▴and a latetDplacement in whichtDfollowst▴. The duration of the early and latetDwas systematically decreased from 30 seconds (i.e.,tD= T) to 0.1 second. Manipulation oftDplacement and duration controlled the temporal separation between response and reinforcement, but it did not affect the frequency of programmed reinforcers, which was 1/T. The results show that early and latetDplacements of equal duration have similar overall effects upon response rate, reinforcer frequency, responses per reinforcer, and obtained response‐reinforcer temporal separation. A stepwise regression analysis using log response rate as the dependent variable showed that the obtained delay was a significant first‐step variable for six of eight subjects, with obtained reinforcer frequency significant for the remaini

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-143

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Two pigeons, with previous exposure to concurrent schedules, were submitted to 29 sessions of 8 hours each with concurrent variable‐interval variable‐interval schedules in which reinforcement parameters changed from session to session. In the first nine sessions reinforcement durations were equal in both schedules while reinforcement frequencies varied; in Sessions 10 through 18, both frequency and duration of reinforcement were varied; in Sessions 19 through 29, only reinforcement duration was varied. Results with this different procedure confirm previous findings that behavior is more sensitive to changes in reinforcement frequency than to reinforcement magnit

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-157

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Six pigeons were trained on concurrent variable‐interval schedules. Two different reinforcer durations were arranged on the left key, and which of these was delivered was determined probabilistically. A single reinforcer duration was arranged on the right key. In Parts 1 and 3 of the experiment, the probability of the left‐key reinforcer durations (1 and 7 seconds in Part 1; 3 and 10 seconds in Part 3) was varied from 0 to 1, keeping the schedules constant and the right‐key reinforcer at 3 seconds. Response allocation to the left key fell as the probability of the shorter left‐key reinforcer duration was increased. In Part 2, one left‐key reinforcer duration was 3 seconds and the other was varied from 0 to 10 seconds, while again the schedules and right‐key reinforcer duration (3 seconds) were kept constant. Left‐key response allocation increased as the varied reinforcer duration on the left key increased. An extension of the generalized matching law failed to provide a good description of response allocation in these procedures. In Part 4, the left‐ and right‐key reinforcer durations were 3 seconds and the variable‐interval schedules were varied. Response allocation was well described by the generalized matching law. Part 5 arranged equal variable‐interval schedules on the left and right keys, 3‐second reinforcers on the right key, and the left‐key reinforcer durations were varied from 1 to 10 seconds. The relationship between the log response and reinforcer‐duration ratios was nonlinear. The effects of varying reinforcer durations in concurrent schedules cannot be described using the generalized matching law with constant parameters. It is suggested more generally that this quantitative relation may not describe performance either when reinforcing situations differ in duration (e.g., with delayed reinforcers) or when response requ

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-169

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Eight human subjects pressed a lever on a range of variable‐interval schedules for 0.25¢ to 35.0¢ per reinforcement. Herrnstein's hyperbola described seven of the eight subjects' response‐rate data well. For all subjects, they‐asymptote of the hyperbola increased with increasing reinforcer magnitude and its reciprocal was a linear function of the reciprocal of reinforcer magnitude. These results confirm predictions made by linear system theory; they contradict formal properties of Herrnstein's account and of six other mathematical accounts of single‐alternative r

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-183

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Pigeons responded in a multiple schedule in which concurrent schedules of brief‐stimulus presentation alternated with a component in which food was available (concurrent‐chains component). In the initial links of the concurrent‐chains component subjects chose either of two stimuli each correlated with the terminal link of one chain. The terminal links involved either variable‐interval 30‐second or variable‐interval 60‐second schedules. In the brief‐stimulus component subjects chose between 0.5‐second presentations of the terminal‐link stimuli from the concurrent‐chains component. Responding was generally maintained in the brief‐stimulus component in two subjects for more than 300 sessions, suggesting that brief stimuli were conditioned reinforcers. During the brief‐stimulus component, in 17 of 21 cases for which a minimal number of responses occurred, choice proportions above 0.55 were obtained for the brief‐stimulus presentations correlated with the higher rate of primary reinforcement in the concurrent‐chains component. These results support the suggestion that choice in conventional concurrent‐chains procedures is partially controlled by producti

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-193

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A procedure is described which disrupts response‐reinforcer contiguity and response dependency and which demonstrates how the location of the response dependency in interval schedules can be regarded as a controlling variable in its own right. Rats' lever pressing produced sucrose on a recycling conjunctive fixed‐time 30‐second fixed‐ratio 1 schedule of reinforcement. Reinforcement occurred only at the end of the fixed‐time component on this schedule and only if a response had occurred during that component. This produced a pause‐respond‐pause pattern during the interreinforcer interval for all animals. When the location of the response dependency was then restricted to a 10‐second period in the middle of the fixed‐time component, the pattern was accentuated and response rates increased for all animals, while postreinforcement pauses decreased sharply for two animals. When responding was required in the first 10 seconds of the fixed‐time component, responding peaked earlier in the interval for all animals. Response rates were slightly below those in the previous conditions, while postreinforcement pauses were between 2 and 6 sec

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-203

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1984.41-211

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY