摘要:

We carried out five experiments with rats on fixed‐time schedules in order to define the relation between drinking and individual food‐pellet presentations. In Experiment 1, unsignaled extra food occurred at the end of occasional fixed intervals, and we compared subsequent drinking patterns with drinking before the extra food presentation. In Experiment 2 we presented signaled and unsignaled extra food and measured elicited and anticipatory drinking patterns. In Experiment 3, we observed the persistence of modified drinking patterns when several consecutive intervals ended with extra pellets. In Experiments 4 and 5, we varied the magnitude of food delivery across (rather than within) sessions to replicate published findings. Results show that schedule‐induced drinking is neither elicited by food presentations nor induced by stimuli associated with a high food rate. All subjects seemed to follow a simple rule: during any stimulus signaling an increase in the local probability of food delivery within a session, engage in food‐related behavior to the exclusion of drinking. Schedule‐induced drinking appears to be the result of dynamic interactions among food‐related behavior, drinking, and other motivated behavior, rather than a direct effect of the contingencies of food re

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-1

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Excessive defecation, typically considered to be a concomitant of stress, was experimentally induced or eliminated under specific schedules of positive reinforcement of lever pressing by rats. The schedules were, by and large, those under which polydipsia is typically induced. In the first of three experiments, rats under fixed‐interval 32‐second schedules and variable interval 32‐second schedules for food and water reinforcers defecated profusely, but not under fixed‐interval one‐second schedules or other small interval schedules. Somewhat higher rates of defecation were observed on variable interval 32‐second schedules than on fixed‐interval 32‐second schedules. In a second experiment, fixed‐ratio schedules were used, some of which resulted in responding such that reinforcement densities were similar to those on the interval schedules that induced defecation. Defecation was not systematically induced by these ratio schedules. In a third experiment, fixed‐time schedules of food presentations were utilized. High rates of defecation were induced comparable to those induced by interval schedules of the same time parameter. No other behavior commonly termed “emotional” was observed in a

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-19

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Since foraging in nature can be viewed as instrumental behavior, choice between sources of food, known as “patches,” can be viewed as choice between instrumental response alternatives. Whereas the travel required to change alternatives deters changeover in nature, the changeover delay (COD) usually deters changeover in the laboratory. In this experiment, pigeons were exposed to laboratory choice situations, concurrent variable‐interval schedules, that were standard except for the introduction of a travel requirement for changeover. As the travel requirement increased, rate of changeover decreased and preference for a favored alternative strengthened. When the travel requirement was small, the relations between choice and relative reinforcement revealed the usual tendencies toward matching and undermatching. When the travel requirement was large, strong overmatching occurred. These results, together with those from experiments in which changeover was deterred by punishment or a fixed‐ratio requirement, deviate from the matching law, even when a correction is made for cost of changeover. If one accepted an argument that the COD is analogous to travel, the results suggest that the norm in choice relations would be overmatching. This overmatching, however, might only be the sign of an underlying strategy approximating optim

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-35

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Performance maintained under concurrent schedules consisting of a variable‐interval avoidance component and a variable‐interval positive‐reinforcement component was studied in three human subjects using points exchangeable for money as the reinforcer. The rate of responding in the avoidance component increased, and the rate of responding in the positive‐reinforcement component declined, as a function of the frequency of point‐losses avoided in the avoidance component. The performance of all three subjects conformed to equations proposed by Herrnstein to describe behavior in concurrent schedules. The logarithms of the ratios of the response rates in the two components, and the logarithms of the ratios of the times spent in the two components, were linearly related to the logarithms of the ratios of the frequency of loss avoidance in the avoidance component to the frequency of reinforcement in the positive‐reinforcement component. When a changeover delay of 5.0 sec was imposed, the slopes of the linear functions were close to 1.0 in the case of two subjects, whereas the third subject exhibited significant undermatching. For two subjects the changeover delay was then reduced to 2.0 sec; in both cases the slopes of the linear functions were lower than under the 5.0‐sec condition. One subject participated in a third phase, in which no changeover delay was imposed; there was a further reduction in the slopes of the lin

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-51

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Six pigeons served in a discrete‐trial experiment on short‐term memory. Combinations of three key positions and two ordinal positions, yielding six possible sequences of stimulus‐response pairs, were used as lists of items. A retention interval separated list presentation from the test phase in which two (for Group 1) or three (for Group 2) keys were illuminated with either red or green light. A reinforcer was delivered if a subject pecked the key of the first item on a red trial and the key of the second item on a green trial. When the retention interval was lengthened from one to five or nine seconds, a systematic loss of stimulus control resulted. Lengthening the interval between items from one to eight seconds had a much smaller effect for the birds in Group 1, whereas a systematic loss of stimulus control was found in red trials for the birds in Group 2. The functional relations between choice accuracy and delay provided an empirical basis for analysis of what relations among temporal events can become discriminative st

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-63

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Variations of the symbolic delayed‐matching‐to‐sample procedure were used to study a pigeon's memory for a small number of pecks. In the first experiment a choice of a left or right sidekey after a delay or retention interval was reinforced if a bird had not pecked at all or had pecked exactly once, before the delay, respectively. In the second experiment a choice of a red or green sidekey, regardless of its position, was reinforced if a bird had not pecked at all or had pecked exactly twice, respectively. In the first experiment a bird could orient toward the correct choice during the delay, whereas it could not in the second experiment. In a third experiment a feature‐probing method was used to study a pigeon's memory for a number of pecks in the context of certain other pecks. The results showed that a pigeon can remember a small number of pecks for one‐half to one minute or more and that the percent correct is a decreasing function of the log retention interval. When a second number of pecks is different from the first number, memory for the first number lasts only a few seconds. When a second number is the same, memory lasts considerably longer. The more recent number of pecks is remembered better. The results are interpreted in terms of a theory which holds that a reinforcer, in general, may act on a subjects' memory for recent behavior to generate patterns of

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-71

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Vervet and grivet monkeys were repeatedly tested eating bar‐ and circle‐shaped cookies. One subject was always injected with lithium immediately after eating cookies with the circle shape and learned to avoid the circular cookies while continuing to eat the bar‐shaped cookies. Another subject received similar treatment except that lithium injections were always delayed 30 minutes after access to the circle‐shaped cookies. She also acquired a discriminative aversion. Aversion learning was not observed with 60‐minute delayed toxicosis or with lithium injections administered unpaired with access to the cookies. The two types of cookies differed only in shape, and conditioning and test sessions were conducted in total darkness to preclude the use of visual cues. Therefore, the avoidance observed in subjects conditioned with immediate and 30‐minute delayed toxicosis represents a conditioned aversion to the shape of the cookies as revealed by tactile cues. These findings illustrate that monkeys can learn to select food on the basis of tactile stimuli when such stimuli are conditioned with delayed aversive

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-87

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-92

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Rats were required to earn their food in a large room having nine boxes placed in it, each of which contained food buried in sand. In different phases of the experiment the amount of time allowed for foraging, the amount of food available in each food patch, and the location of the different available amounts were varied. The rats exhaustively sampled all patches each session but seemed to have fairly strong preferences for certain locations over others. If position preferences were for patches containing small amounts of food, the sensitivity to amount available was increased so that when location was compensated for, a pattern of optimal foraging was evident. The importance of environmental constraints in producing optimal behavior and the relation of the observed behavior to laboratory findings are discussed.

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-93

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

When the rate of reinforcement for pigeons' key pecking varied over time following a sine waveform, performances were more consistent and reliable if a constant‐rate reinforcement schedule was concurrently available on a second key than if only the sinewave‐varying reinforcement schedule was available. In the two‐key version, response rates clearly followed varying reinforcement rates with the same frequency, with no phase lag, and without breaks. In both versions, pecking rate was a power function of reinforcement rate. Sinewave‐schedule performance waveforms qualified for engineering methods of frequency analysis and met criteria for a standard measurement

ISSN:0022-5002    

DOI:10.1901/jeab.1982.38-101

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY