摘要:

In the first stage of a two‐stage choice, human subjects chose between probabilistic access to a second choice (between a small high‐probability reward and a large low‐probability reward) and commitment to the large low‐probability reward. When confronted with the second‐stage choice, subjects strongly preferred the small high‐probability reward. When the first‐stage probability (of access to the second stage) was high, subjects strongly preferred the path leading to the choice in the second stage. But when the first‐stage probability was low, subjects committed themselves to the large low‐probability reward. These results parallel those obtained by Rachlin and Green (1972) with pigeons and constitute some evidence that probabilities may be inte

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-347

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

In a conditional discrimination procedure, pigeons' observing responses were analyzed to examine whether two color stimuli (blue or red), conditionally related to whether each of two line stimuli (vertical or horizontal) accompanied reinforcement or nonreinforcement, functioned as conditioned reinforcers. If a variable‐interval (VI) 10‐s requirement was fulfilled, an observing response produced onset of a color stimulus. A little later, a line stimulus was presented independently of responding, added to the color stimulus to form a compound stimulus. If 55 s elapsed with a response not having occurred either through 55 s or after the variable‐interval 10‐s had timed out, one of the color—line compound stimuli was presented independently of responding. To control for sensory reinforcement effects and for earlier entrance to the later link, a simple discrimination procedure also was conducted in which reinforcement was not correlated with the color stimuli but with the line stimuli only. As in the conditional discrimination, the observing response also could produce earlier presentation of blue or red. The observing response occurred more frequently during the conditional discrimination than during the simple discrimination. The results were related to different theoretical accounts of conditioned reinforcement, particularly the information h

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-355

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Four pigeons were exposed to multiple schedules and later to concurrent‐chains schedules, with terminal links that had previously been multiple‐schedule components. For 2 birds, the terminal‐link schedules arranged an inverse relationship between response rate and reinforcement rate; for the other 2 birds a direct corresponding relationship was arranged. Those response rates were further modified by differentially reinforcing either longer or shorter interresponse times, relative to the current means. Although the birds' initial‐link responses indicated preferences for terminal links with higher rates of reinforcement, in half the cases the birds responded during the terminal links in such a way as to produce lower rates of reinforcement, rates their initial‐link behavior indicated they did not prefer. That outcome is inconsistent with maximization theory, but consistent with a strengthening analysis of behavior on single‐ke

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-367

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-382

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The effects on pigeons' key pecking of unsignaled delays of reinforcement and response‐independent reinforcement were compared after either variable‐interval or differential‐reinforcement‐of‐low‐rate baseline schedules. One 30‐min session arranging delayed reinforcement and one 30‐min session arranging response‐independent reinforcement were conducted daily, 6 hr apart. A within‐subject yoked‐control procedure equated reinforcer frequency and distribution across the two sessions. Response rates usually were reduced more by response‐independent than by delayed but response‐contingent delivery of reinforcers. Under both schedules, response rates were lower when obtained delays were greater. These results bear upon methodological and conceptual issues regarding comparisons of contingencies that change the temporal resp

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-383

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The behavior of individual pigeons on fixed‐ratio, variable‐ratio, and random‐ratio schedules was examined. Within each type of ratio schedule the size of the ratio was varied in an irregular sequence. At various ratio sizes (5, 10, 40, 80) no differences were found among overall response rates (post‐reinforcement pause plus running response rate) as a function of ratio type. This similarity in overall response rates held despite noticeable differences in the microstructure of performance both within and across subjects; the primary performance difference on the three types of ratio schedules was the relatively longer postreinforcement pause duration on the fixed‐ratio schedule. We concluded that the gross temporal characteristics of performance determined by the relative weightings of the postreinforcement pause and running response rate were primarily controlled by the type of ratio schedule (fixed, variable, or random), whereas the overall rate of responding was controlled by the size of

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-395

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

This experiment attempted to disentangle response‐rate reductions controlled by the direct suppressive effects of a punisher from those due to negative reinforcement of response omission. Key‐peck responding of pigeons was maintained by a conjoint variable‐interval 3‐min schedule of food presentation variable‐interval 30‐s schedule of response‐dependent electric shock presentation. Omission of responses for 5, 10, or 30 s resulted in the possibility of canceling a scheduled shock. Response rates were a function of required pause duration, with lower rates occurring when longer periods of response omission were required for shock cancellation. These results show that, with several parameters of punishment held constant, response rates were controlled by the negative reinforcement contingency. Such a finding argues for renewed consideration of the role of negative reinforcement in punishment

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-407

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Food‐deprived rats were exposed to a fixed‐time 60‐s schedule of food‐pellet presentation and developed schedule‐induced drinking. Using an ABA reversal design, three experiments investigated the effects of events then made dependent on licks. In Experiment 1, lick‐dependent signaled delays (10 s) in food presentation in general led to decreased drinking, which recovered when the signaled delays were discontinued. The drinking of yoked‐control rats, which received food at the same times as those exposed to the signaled‐delay contingency, showed much smaller changes. Experiment 2 showed that 10‐s lick‐dependent signals alone did not reduce drinking. In Experiment 3, when licks produced unsignaled 10‐s delays in food there were less marked and more gradual changes in drinking than in Experiment 1, although these effects again were greater than with yoked‐control animals. We concluded that both signaled and unsignaled delays functioned as punishers of drinking. These findings support the view that schedule‐induced drinking, like operant behavior, is subject to co

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-417

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Design and construction of an automatic pellet dispenser for granivorous birds are described. The dispenser permits rapid pneumatic delivery of pellets (five pellets per second maximum) to one controlled position and does not interfere with simultaneous electrophysiological recording. In addition, the device continuously indicates presence or absence of a pellet in the delivery position. This automatic dispenser proved very effective in our studies of stereotyped topographies of feeding in granivorous birds, such as pigeons and chickens.

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-435

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1987.48-439

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY