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1.
Andrew R. Delamater 《Learning & behavior》1997,25(4):400-412
In two experiments, the possibility of outcome-selective reinstatement of conditioned responding was examined. Evidence for outcome-selective reinstatement of previously extinguished appetitively conditioned magazine responses by rats was observed in both Pavlovian (Experiment 1) and discriminated instrumental conditioning (Experiment 2) procedures. In both experiments, stimulus-elicited magazine responses occurred more in the presence of a stimulus whose reinforcer was reinstated than they did in the presence of another stimulus whose reinforcer was not reinstated. This effect was observed after both brief and extensive amounts of extinction. Outcome-selective reinstatement of instrumental leverpressing, however, was not observed, although nonselective reinstatement of magazine responding and leverpressing was obtained in Experiment 2. Overall, the data from these studies challenge existing theories of reinstatement, and they provide additional evidence of the importance of outcome-specific processes in the control of learned performance. 相似文献
2.
Robert A. Rescorla 《Learning & behavior》1993,21(4):327-336
The associative changes that occur in extinction were investigated in four instrumental learning experiments. Experiment 1 used transfer based on a shared outcome to detect the continued presence of response-outcome (R-O) and stimulus-outcome (S-O) associations after a response had been nonreinforced in the presence of its controlling stimulus. Experiments 2–4 found that extinction resulted in the learning not to make a particular response in the presence of a particular stimulus, despite those continued R-0 and S-0 associations. These results suggest that extinction may superimpose upon those original outcome associations an inhibitory S-R association. 相似文献
3.
The role of incentive learning in instrumental performance following an upshift in the degree of water deprivation was analyzed in three experiments. In Experiments 1A and 1B, rats trained to perform an instrumental action reinforced by either sucrose or maltodextrin solutions when in a low-deprivation state were shifted to a high-deprivation state and tested in extinction. This shift in water deprivation increased performance only if the animals had been exposed to the reinforcer in the high-deprivation state prior to testing. In Experiment 2, the role of the instrumental contingency in mediating the preexposure effect observed in the first two studies was examined by training rats to make two instrumental actions for different outcomes. The preexposure experience with the outcomes produced a relative increase in performance of the action reinforced with the incentive preexposed in the high-deprivation state when a choice between the two response alternatives was conducted in that state. These experiments support the conclusion that instrumental performance following revaluation of the reinforcer by an upshift in the level of thirst depends on a process of incentive learning. 相似文献
4.
Two experiments examined the effects of extended training on the development of response-reinforcer associations. Rats were trained by using various food reinforcers to make multiple instrumental responses. Subsequently, those reinforcers were devalued by being paired with a toxin. The presence of response-reinforcer associations was inferred from the decrease in the likelihood of a response following devaluation of its reinforcer. Such response-reinforcer associations are known to contribute to performance after moderate amounts of training. These experiments addressed the question of whether the contribution of those associations remains constant, increases, or decreases with more extended training. Experiment 1 found that even after a response had been extensively trained with one reinforcer, the substitution of a new reinforcer produced new associations between the response and that new reinforcer. After extended training, a response continued to acquire new associations with a reinforcer, as indexed by the impact of a devaluation procedure. Experiment 2 directly compared the contribution of reinforcers used extensively and moderately with the same response. It found that devaluation of the extensively used reinforcer more effectively reduced performance of the response, suggesting that the associations formed with additional training contribute to performance of the response. These experiments indicate that the contribution of response-reinforcer associations does not decrease but, instead, continues to grow throughout the course of extended instrumental training. 相似文献
5.
We conducted three experiments to investigate the associative structure underlying the reinstatement of instrumental performance
after extinction. In each experiment, rats were initially rewarded on two responses with different outcomes. At test, both
responses were extinguished in order to assess the impact of a single noncontingent outcome delivery on response selection.
Experiment 1 found evidence of outcome-selective reinstatement (i.e., more responses were performed on the lever that was
trained with the reinstating outcome than on the other lever). Experiment 2 demonstrated that the outcome’s capacity to reinstate
performance was not affected by a reduction in its motivational value. Experiment 3 found evidence that the reinstating outcome
selectively retrieved the response it signaled rather than the response it followed during training. Together, these findings
are consistent with the view that instrumental reinstatement depends on the discriminative stimulus properties of the reinstating
outcome. 相似文献
6.
The role of incentive learning in instrumental performance following a shift in the degree of water deprivation was analyzed in three experiments. In Experiments 1A and IB, rats trained to perform an instrumental action reinforced with either sucrose or maltodextrin solutions when in a high-deprivation state were subsequently shifted to a low-deprivation state and tested in extinction. This within-state shift in water deprivation reduced instrumental performance only when the animals had been exposed to the reinforcer in the low-deprivation state prior to instrumental training. In Experiment 2, a concurrent training procedure was used to assess whether the change in the value of the reinforcer brought about by preexposurewas mediated by the contingency between the instrumental action and the reinforcer. Preexposure to the reinforcer under the low-deprivation state produced a selective reduction of the performance of the action upon which it was contingent during training when testing was conducted in extinction following a shift from the high- to the low-deprivation state. These experiments provide evidence that animals have to learn about the incentive value of a reinforcer in a particular motivational state through exposure to the reinforcer in that state. 相似文献
7.
In three experiments that used appetitive preparations with rats, we examined the effects of reinforcing a compound consisting of two previously reinforced stimuli on subsequent responding to those stimuli. Experiment 1 showed that a Pavlovian conditioned stimulus given this treatment evoked fewer magazine entries when presented alone than did a reinforced stimulus that did not receive the compound treatment. Experiment 2 examined inhibition of delay and generalization decrement accounts for the results of Experiment 1. Experiment 3 extended this finding to an instrumental learning paradigm. 相似文献
8.
Ruth M. Colwill 《Learning & behavior》1991,19(4):326-336
Three experiments using rats examined whether a signal for the nonreinforcement of an instrumental response (S-) provided information about the identity of the omitted outcome. In all three experiments, one stimulus was established as a signal for the nonreinforcement of a response that earned food pellets and another stimulus signaled the nonreinforcement of a response that earned liquid sucrose. Experiment 1 found that each S-suppressed another instrumental response trained with the same outcome significantly more than a response trained with a different outcome. Using a variant of this transfer design, Experiment 2 demonstrated that an S- was slower to develop discriminative control over a new response reinforced in its presence with the same outcome compared with an outcome different from the one whose omission-the S- had previously signaled. Experiment 3 examined transfer of the S- stimuli to a response trained with two outcomes, one of which had subsequently been devalued. Performance of this response significantly increased in the presence of a signal for the omission of the devalued outcome, but decreased in the presence of a signal for the omission of the valued outcome. These results suggest that S-s do provide information about the identity of omitted response-contingent outcomes. 相似文献
9.
In each of two experiments, rats were trained to press the lever in a Skinner box, food reinforcement being available on a variable-interval 60-sec schedule (VI 60). There followed an “exposure phase” for which the levers were removed from the boxes, and then a final test with the levers replaced to assess the effects of the intervening treatment on instrumental responding. Experiment 1 showed that simple exposure to the box reduced the vigor of instrumental performance in comparison with a condition in which food was made available during the exposure phase. Animals which received no exposure treatment also showed a relatively high rate of response. Experiment 2 demonstrated that an exposure treatment in which the occurrence of food is signaled by a light stimulus also leads to a decline in instrumental responding. These results are held to support the notion that associations between the context and the reinforcer serve to energize appetitive instrumental behavior. 相似文献
10.
John H. Hull 《Learning & behavior》1977,5(2):207-212
Experiments 1, 2, and 3 showed that food-deprived rats responding for food pellets made significantly more long-duration leverpresses than water-deprived rats responding for water drops. These experiments further showed that this difference in instrumental response topography is long-lived, and depends neither upon idiosyncrasies of the experimental chamber nor upon severity of deprivation conditions. In Experiment 4, food-deprived rats responding for food pellets made significantly more long-duration leverpresses than did either food- or water-deprived rats responding for sucrose solution. Human judges in Experiment 5 were able to correctly identify instrumental leverpress responses by rats as being for food or water based solely on previous viewings of other rats drinking water or eating food pellets. It appears that instrumental response topographies in rats vary depending principally upon the reinforcer received, and that these instrumental response topographies resemble consummatory response topographies. 相似文献
11.
Kelly J. Stanhope 《Learning & behavior》1989,17(3):311-321
A dissociation between the effect of reinforcer type and response strength on the force of the pigeon’s keypeck response was shown in three experiments. In Experiment 1, pigeons were trained to peck two conditioned stimuli, one paired with water and another paired with grain. The pigeons made more forceful pecks for grain than for water and also showed a tendency, albeit an unreliable one, to respond on a higher percentage of food trials than water trials. In Experiment 2, the pigeons from Experiment 1 were satiated with either food or water and were then presented with the two conditioned stimuli in an extinction test. It was found that, regardless of the drive state, the pigeons made more forceful pecks to the stimulus that predicted food than to the stimulus that predicted water. In the thirsty group, however, this difference in force was not accompanied by a difference in the percentage of trials with a response. In Experiment 3, pigeons trained with a single reinforcer pecked more often on instrumentally reinforced trials than on Pavlovian conditioning trials, but there was no difference in the force of the pecks. Taken together, these results imply that differences in response strength cannot account for the difference between the force of food- and water-reinforced pecks. Instead, stimulus-substitution theory may provide the best account of the topography of the two types of pecks. 相似文献
12.
Three experiments, using rats, demonstrated the encoding of a food unconditioned stimulus (US) in a simple Pavlovian conditioning paradigm. In all three studies, one stimulus was used to signal the delivery of pellets and a different stimulus was used to signal the delivery of sucrose. In Experiment 1, postconditioning devaluation of one of the food USs selectively reduced the frequency of conditioned magazine-directed behavior during the stimulus trained with that US. In Experiment 2, transfer of the stimuli to instrumental responses resulted in selective depression of the response trained with a different outcome. In Experiment 3, acquisition of stimulus-outcome learning was impaired by unsignaled intertrial presentations of the same outcome but not of a different outcome. These results indicate that a detailed representation of the outcome is encoded in the normal course of Pavlovian conditioning. 相似文献
13.
The effect of food deprivation level at the time of initial exposure to a subsequent food reinforcer was investigated in two experiments. In Experiment 1, deprivation at the time of initial exposure influenced the subsequent acquisition and extinction of an instrumental response. In Experiment 2, the residual deprivation effect associated with a reduction in deprivation level occurred only when rats initially experienced the reinforcer at a high, as compared with a low, deprivation level. Results were discussed in terms of the assumption that the limits of incentive generated by a reinforcer are influenced by the deprivation state at the time of first exposure to that reinforcer. 相似文献
14.
A second-order autoshaping procedure was used to examine the effects of three variables on the amount of information that could be learned about the stimulus properties of a reinforcer. All three experiments paired several keylight S2s with different keylight S1s and then carried out discriminative autoshaping with those S1s. Learning about the stimulus properties of S1 was inferred from changes in the response to its paired S2 when that S1 was changed in value. The sensitivity of S2 to changes in S1 was investigated as a function of number of S2-S1 pairings (Experiment 1), partial reinforcement (Experiment 2), and temporal distance between S2 and S1 (Experiment 3). Each experiment found evidence of a selective change in responding to an S2 as a function of the treatment of its S1. However, the amount of that change was not affected by any of the three variables studied. Those results imply that, within the ranges used here, none of these variables changes the degree of learning about the stimulus properties of a reinforcer. 相似文献
15.
Philippe Oberling Adam S. Bristol Helena Matute Ralph R. Miller 《Learning & behavior》2000,28(2):172-186
Miller and Matute (1996) showed that blocking is attenuated when the blocked conditioned stimulus (CS) is “biologically significant” (i.e., when the CS has the potential to elicit vigorous responding of any kind). To the extent that blocking is representative of cue competition, this finding suggests that biological significance protects CSs against cue competition effects in general. In the present experiments, we tested this possibility by examining the influence of biological significance of CSs on other examples of cue competition, namely, overshadowing, the relative stimulus validity effect, and the degraded contingency effect in rats. In Experiment 1, we found that intense auditory stimuli induced transient unconditioned lick suppression, thereby indicating that intense sounds were of high inherent biological significance. In Experiment 2A, we found that cues with high inherent biological significance were protected from overshadowing. In Experiment 2B, this finding was extended to cues with high acquired biological significance, which was obtained through prior pairings with a reinforcer of the valence opposite to that used in the overshadowing treatment. In Experiments 3 and 4, we found that cues with high inherent biological significance attenuated the relative validity effect and the degraded contingency effect, respectively. These results lend support to the view that biological significance (inherent and acquired) protects stimuli from cue competition effects, a finding that is problematic for many contemporary theories of learning. 相似文献
16.
In two experiments, two groups of rats were trained in a navigation task according to either a continuous or a partial schedule
of reinforcement. In Experiment 1, animals that were given continuous reinforcement extinguished the spatial response of approaching
the goal location more readily than animals given partial reinforcement—a partial reinforcement extinction effect. In Experiment
2, after partially or continuously reinforced training, animals were trained in a new task that made use of the same reinforcer
according to a continuous reinforcement schedule. Animals initially given partial reinforcement performed better in the novel
task than did rats initially given continuous reinforcement. These results replicate, in the spatial domain, well-known partial
reinforcement phenomena typically observed in the context of Pavlovian and instrumental conditioning, suggesting that similar
principles govern spatial and associative learning. The results reported support the notion that salience modulation processes
play a key role in determining partial reinforcement effects. 相似文献
17.
Ruth M. Colwill 《Learning & behavior》1993,21(4):337-345
The effect of training a positive discriminative stimulus (S+ ) as a signal for the nonreinforcement of an instrumental response (S?) on the ability of that stimulus to evoke its original instrumental response was examined in three experiments using rats. In all three experiments, two different stimuli were established as S+s for different response-outcome relations. In Experiment 1, an S+ was less effective in controlling its original response after it had undergone training as an S? for a new response that earned the same outcome than it was after training as an S? for a response that earned a different outcome. Experiment 2 established that this effect was not mediated by Pavlovian inhibitory conditioning produced by the negative correlation between the S+ and the outcome during S? training. Simply arranging a negative correlation between S+ and the outcome whose occurrence it had previously signaled did not impair the ability of that S+ to elicit its original response. In Experiment 3, the response-evoking properties of an S+ were found to be undermined by using the S+ as a signal for the simple extinction of a new response trained with the same outcome, but not with a different outcome. These results suggest that positive discriminative stimuli use their associations with the outcomes earned in their presence to control the responses that earned those outcomes. 相似文献
18.
In three experiments, we assessed the role of signals for changes in the consequences of cues as a potential account of the
renewal effect. Experiment 1 showed recovery of responding following extinction when acquisition, extinction, and test phases
occurred in different contexts. In addition, extinction treatment in multiple contexts attenuated context-induced response
recovery. In Experiment 2, we used presentations of an extraneous stimulus (ES), instead of context shifts, and found that
responding recovered from extinction only when the ES was presented both between acquisition and extinction and between extinction
and test. In Experiment 3, we used a reversal learning design in which, during training, two cues were first paired with different
outcomes, then paired with the alternative outcomes, and finally paired again with the original outcomes. In this experiment,
presentation, just prior to testing, of an ES that had previously been presented between the different phases produced an
expectation of reversal in the meaning of the cues. 相似文献
19.
Three different techniques were employed to analyze the associative structures mediating performance on an instrumental biconditional discrimination. In all three experiments, rats were trained concurrently on two tasks in which different stimuli signaled which one of two responses would be followed by reward. In each task, one response was rewarded in one stimulus and the other response was rewarded in the other stimulus. Correct responses earned pellets in one task and sucrose in the other task. The transfer procedure was used in Experiment 1A to identify whether or not an association developed between a biconditional discriminative stimulus and its instrumental outcome. Evidence was obtained that a biconditional cue elevated preferentially a new response trained with the same outcome. Experiments 1B and 3 examined the potential contribution of this stimulus-outcome association to biconditional performance by training the biconditional cues as signals (S-s) for the nonreinforcement of a different response. There was no evidence that this operation interfered with the ability of a biconditional cue to control performance of its correct response. In Experiments 1B and 2, the value of the instrumental outcome was reduced in an attempt to assess the contribution of stimulus-response associations to performance on the biconditional discrimination. The results of Experiments 1B and 2 reveal that correct responses were depressed following devaluation of the outcome used to train them, suggesting that learning about the response-outcome relation occurs. The implications of these results for binary and hierarchical models of instrumental learning are discussed. 相似文献
20.
In three experiments, we examined the effect of response-outcome relations on human ratings of causal efficacy and demonstrated
that such efficacy ratings transfer to novel situations through derived stimulus relations. Causal efficacy ratings were higher,
and probability of an outcome given a response was lower, for a differential reinforcement of high rate schedule than for
either a differential reinforcement of low rate schedule (Experiment 1) or a variable interval schedule (Experiment 2). In
Experiment 3, we employed schedules that were equated for outcome probability and noted that ratings of causal efficacy and
the rate of response were higher on a variable ratio than on a variable interval schedule. For participants in all three experiments,
causal efficacy ratings transferred to the stimulus present during each schedule and generalized to novel stimuli through
derived relations. The results corroborate the view that schedules are a determinant of both response rates and causal efficacy
ratings. In addition, the novel demonstration of a mechanism of generalization of these ratings via derived relations has
clinical implications. 相似文献