共查询到20条相似文献，搜索用时 734 毫秒
1.
Rats trained in one context to use stimuli arising from food deprivation as discriminative signals for shock were tested in other contexts to assess the basis of conditioned responding (i.e., freezing or behavioral immobility). In Experiment 1, discriminative control by 24-h food-deprivation cues failed to promote transfer responding in a test context that had no association with shock. This indicated that food deprivation cues had little direct excitatory power. However, transfer of behavioral control by 24-h food-deprivation cues was obtained in a context paired with shock only when the rats were 19 h water deprived. This finding agrees with the idea that food-deprivation cues become conditioned modulators of the capacity of external stimuli to activate their association with an unconditioned stimulus. In Experiment 2, rats trained to use 24-h food-deprivation cues as signals for shock exhibited significantly greater transfer performance when the transfer context had undergone partial extinction relative to when the transfer context had undergone only simple excitatory training. This finding with deprivation cues and transfer contexts (1) paralleled earlier results obtained with discrete (auditory and visual) conditioned modulators and transfer targets, and (2) posed difficulties for associative summation and generalization interpretations of transfer performance. 相似文献
2.
David R. Thomas Alan R. McKelvie Michael Ranney Thomas B. Moye 《Learning & behavior》1981,9(4):581-586
In Experiment 1, three (experimental) groups of pigeons (n=8) acquired a successive wavelength discrimination in Phase 1 and a reversal in Phase 2; then, after a 24-h delay, they received a wavelength generalization test in extinction (Phase 3). For one group (“Context Same”), the same context was present throughout; for both others, a different context was used for Phase 1 and Phase 2. One group received the generalization test in the presence of Context 1, the other in Context 2. The Context Same and Context 2 experimental groups showed “recency,” with all gradients peaking at the reversal S+ value. The Context 1 group yielded several different response patterns but never showed recency, thus revealing context-generated proactive interference. In Experiment 2, eight subjects learned the original discrimination and its reversal in different contexts, and each bird was tested alternately (within a session) in both contexts. Under this condition, the test contexts were effective retrieval cues. In every case, the gradients obtained in each context peaked sharply at the appropriate S+ value. These experiments indicate that conflicting memories may be stored along with their associated contexts such that they can be retrieved by an appropriate manipulation of contextual cues at the time of retention testing. 相似文献
3.
These studies demonstrated the acquisition and extinction of conditioned tolerance to the analgesic effect of nicotine in
rats. In Experiment 1, distinctive environmental cues were either paired or unpaired with nicotine. Following acquisition,
the paired group was more tolerant to nicotine than the unpaired and saline groups. Conditioned tolerance was extinguished
in the paired group after placebo sessions in the distinctive environment. Experiment 2 examined whether the distinctive environment
functioned as a CS or as an occasion setter for injection cues. After acquisition, exposure to the distinctive environment,
with or without placebo injections, resulted in extinction. This demonstrates that the distinctive environment served as a
CS, not as an occasion setter for injection cues. 相似文献
4.
Two conditioned suppression experiments with rats were conducted to determine whether the spontaneous recovery and renewal
that are commonly observed in retroactive outcome interference (e.g., extinction) also occur in retroactive cue interference.
Experiment 1 showed that a long delay between Phase 2 (the interfering phase) and testing produces a recovery from the cue interference
(i.e., the delay enhanced responding to the target cue trained in Phase 1), which is analogous to the spontaneous recovery
effect observed in extinction and other retroactive outcome interference procedures. Experiment 2 showed that, when target and interfering cues are trained in separate contexts and testing occurs in a different but familiar
context, a recovery from the cue interference is also observed (i.e., the context shift enhanced responding to the target),
which is analogous to ABC renewal from extinction. The results are discussed in terms of the possibility that similar associative
mechanisms underlie cue and outcome interference. 相似文献
5.
Previous research has demonstrated that discrete cues presented during extinction of a conditioned response (extinction cues) subsequently reduce spontaneous recovery and the renewal effect. In order to assess whether an extinction cue’s effect is due to conditioned inhibition, the effect of pairing an extinction cue with food on the cue’s capacity to modulate spontaneous recovery was investigated in an appetitive conditioning experiment with rats. Conditioned inhibitors paired with the unconditioned stimulus lose their potential to inhibit responding. The food-paired extinction cue did not lose its potential to reduce spontaneous recovery. In fact, it reduced spontaneous recovery more than did an extinction cue that was not paired with food. The results indicate that extinction cues attenuate postextinction recovery of conditioned responding through a mechanism other than conditioned inhibition. The cue’s action appears to be similar to that of serial negative occasion setters. Theories of spontaneous recovery and the relationship of extinction cues to other modulatory stimuli are discussed. 相似文献
6.
In the present experiments, savings phenomena following a limited amount of initial acquisition and extended extinction were
examined. Experiments 1 and 2 compared rates of reacquisition following brief acquisition and various amounts of extinction
in conditioning of the rabbit’s nictitating membrane and heart rate response, respectively. Experiment 3 compared rates of
acquisition to a novel stimulus (e.g., light) following brief acquisition and various amounts of extinction to another stimulus
(e.g., tone). In addition, in Experiment 3 recovery of responding to the extinguished stimulus during acquisition to the novel,
cross-modal stimulus was examined. Experiments 1, 2, and 3 demonstrated that with a limited number of acquisition trials (1)
there was a graded reduction in the rate of reacquisition as a function of the number of extinction trials in both conditioning
preparations, (2) there was a graded reduction in the rate of cross-modal acquisition as a function of the number of extinction
trials, but (3), in Experiment 3, recovery of responding to the extinguished stimulus during cross-modal training of the novel
stimulus appeared uniformly robust even in the face of extended extinction. 相似文献
7.
In two experiments, we examined the effect of reversal learning on the status of initially learned associations. In Experiment
1, thirsty rats were first taught to associate one flavor with sucrose and another flavor with Polycose. These relations were
then reversed in a subsequent phase. One of the nutrients was then devalued by being paired with lithium chloride. The results
of a two-bottle flavor-choice test revealed that the most recently learned associations governed performance. In Experiment
2, we aimed to discern whether the initially learned associations in Experiment 1 were weakened or masked by reversal learning.
In order to address this question, either a 1-day (Group Immediate) or a 21-day (Group Delayed) retention interval was interpolated
between the reversal and devaluation phases. Subsequent flavor-choice tests revealed that Group Immediate avoided the flavor
most recently associated with the devalued nutrient but that Group Delayed avoided the flavor that was initially associated
with the devalued nutrient. These findings suggest that the second-learned associations do not erase, but transiently mask,
the first-learned associations, which subsequently recover over a retention interval. These results suggest a parallel in
the mechanisms of extinction and reversal learning. 相似文献
8.
In four experiments utilizing an appetitive conditioning preparation, reacquisition of conditioned responding was found to occur both rapidly and slowly following extinction. In Experiment 1, acquisition of responding to a tone that had been conditioned and extinguished occurred more rapidly than acquisition in either a group that received equivalent exposure to the food unconditioned stimulus or a “rest” control group that received only exposure to the apparatus in the first two phases. However, reacquisition was impaired relative to acquisition in a “learning-experienced” group that had previously received conditioning and extinction with a different stimulus. Experiments 2 and 3 produced similar results, but also found that high responding during reacquisition was confined to trials that followed reinforced, rather than nonreinforced, trials. Experiment 4, in which very few initial conditioning trials were used, produced reacquisition that was slow compared with both learning-experienced and rest controls. The results are consistent with a role for sequential learning: Reacquisition is rapid when animals have learned that reinforced trials signal other reinforced trials. 相似文献
9.
Three experiments with rat subjects examined the effects of contextual stimuli on performance in appetitive conditioning. A 10-sec tone conditioned stimulus (CS) was paired with a food-pellet unconditioned stimulus (US); conditioning was indexed by the observation of headjerking, a response of the rat to auditory stimuli associated with food. In Experiment 1, a context switch following initial conditioning did not affect conditioned responding to the tone; however, when the response was extinguished in the different context, a return to the original conditioning context “renewed” extinguished responding. These results were replicated in Experiments 2 and 3 after equating exposure to the two contexts (Experiment 2) and massing the conditioning and extinction trials (Experiment 3). The results of Experiment 1 also demonstrated that separate exposure to the US following extinction reinstates extinguished responding to the tone; this effect was further shown to depend at least partly on presenting the US in the context in which testing is to occur (Experiments 2 and 3). Overall, the results are consistent with previous data from aversive conditioning procedures. In either appetitive or aversive conditioning, the context may be especially important in affecting performance after extinction. 相似文献
10.
Rats were used in a lick suppression preparation to assess the contribution of conditioned-stimulus (CS)–context and context–unconditioned-stimulus
(US) associations to experimental extinction. Experiment 1 investigated whether strengthening the CS–acquisition context association enhances extinction by determining whether stronger
extinction is observed when CS-alone trials (i.e., extinction treatment) are administered in the acquisition context (AAC
renewal), relative to a context that is neutral with respect to the US (ABC renewal). Less recovery of responding to the CS
was observed in the former than in the latter case, extending the finding that AAC renewal is weaker than ABC renewal to our
lick suppression preparation. Experiment 2 assessed the contribution of the acquisition context–US association to extinction of a CS by examining the effect of postextinction
exposure to the acquisition context on responding to the extinguished CS. This manipulation enhanced responding to the extinguished
CS in AAC, but not ABC, renewal. Experiment 3 addressed the contribution of the CS–acquisition context association by examining the potential of a neutral stimulus, presented
in compound with the target CS during extinction treatment, to overshadow the CS–acquisition context association. This manipulation
enhanced responding to the extinguished CS in AAC, but not ABC, renewal. The results stress the important role of contextual
association in extinction and renewal. 相似文献
11.
Behavior reduced as a consequence of extinction or intervention can relapse. According to behavioral momentum theory, the extent to which behavior persists and relapses once it has been eliminated depends on the relative training reinforcement rate among discriminative stimuli. In addition, studies of context renewal reveal that relapse depends on the similarity between the training stimulus context and the test stimulus context following disruption by extinction. In the present experiments with pigeons, we arranged different reinforcement rates in the presence of distinct discriminative stimuli across components of a multiple schedule. Following extinction, we attempted to reinstate responding in the presence of those target components with response-independent food presentations. Importantly, we arranged the reinstating food presentations either within the target components or in separate components, either paired with extinction (Experiment 1) or reinforcement (Experiment 2) during baseline. Reinstatement increased with greater training reinforcement rates when the reinstating food presentations were arranged in the target components and the separate components paired with reinforcement during training. Reinstatement was smaller and was not systematically related to training reinforcement rates in the target components when reinstating food presentation occurred in separate components paired with extinction. These findings suggest that relapse depends on the history of reinforcement associated with the discriminative stimuli in which the relapse-inducing event occurs. 相似文献
12.
Richard V. Krane 《Learning & behavior》1980,8(4):513-523
The types of conditioned properties acquired by novel (i.e., nonpreexposed) or familiar (i.e., preexposed) exteroceptive cues that were paired with toxicosis, in the absence of a flavor CS, were evaluated in four experiments. In Experiment 1, the conditioned properties of novel exteroceptive cues served to block the acquisition of an aversion to a flavor CS during flavor conditioning and to suppress the ingestion response during flavor testing; animals failed to suppress their ingestion of either the flavor CS or a neutral flavor when tested in the absence of the exteroceptive CS, but suppressed their ingestion of both the flavor CS and the neutral flavor when tested in the presence of the exteroceptive CS. In Experiment 2, preexposed exteroceptive cues that had been paired with toxicosis failed to provide evidence of such conditioned properties. Experiment 3 demonstrated that preexposed contextual cues that were reinforced in compound with novel exteroceptive cues failed to acquire the conditioned properties acquired by nonpreexposed contextual cues under the same conditions of reinforcement. Finally, in Experiment 4, the conditioned properties of the novel exteroceptive cues served to evoke a conditioned gastrointestinal response that gradually extinguished as a function of repeated nonreinforced exposures to the exteroceptive cues, and, in the absence of such extinction, the conditioned properties served to block the acquisition of a flavor aversion. 相似文献
13.
Peter C. Holland 《Learning & behavior》2018,46(2):134-156
Prior exposure to a conditioned stimulus (CS) typically results in latent inhibition—slower acquisition of associative learning about that stimulus in subsequent training. Here, we found that CS preexposure had different effects on the appetitive conditioning of rats with a sucrose unconditioned stimulus (US) depending on training test procedures, the similarity of preexposure and training procedures, and the choice of response measure. Preexposure to a visual or an auditory stimulus produced facilitation of acquisition of food-cup-directed responding when both of those cues were (separately) paired with sucrose delivery in the training test (Experiments 1 and 3). By contrast, the same preexposure procedure resulted in latent inhibition of food-cup learning if the second stimulus in the test phase was of the same modality as the preexposed stimulus (Experiment 2). In Experiment 3, latent inhibition was enhanced if both phases included a single CS or both phases included both auditory and visual CSs, compared to treatments in which only one CS was presented in one phase but two CSs were presented in the other phase. In Experiment 4, preexposure of an auditory cue slowed subsequent learning about it if the context was salient but enhanced learning if the context was of weaker salience. Finally, a measure of general activity revealed latent inhibition after preexposure in all conditions in all 4 experiments. We discuss the results within several classes of latent inhibition theories, none of which provides a comprehensive account. 相似文献
14.
Retroactive cue interference refers to situations in which a target cue X is paired with an outcome in phase 1 and a nontarget cue Z is paired with the same outcome in phase 2, with less subsequent responding to X being seen as a result of the phase 2 training. Two conditioned suppression experiments with rats were conducted to determine whether retroactive cue interference is similarly modulated by a manipulation that influences retroactive outcome interference (e.g., extinction). Both experiments used an ABC renewal-like design in which phase 1 training, phase 2 training, and testing each occurred in different contexts. Experiment 1 found that training the target association in multiple contexts without altering the number of training trials during phase 1 decreased retroactive cue interference (i.e., increased responding consistent with the target association). Experiment 2 found that training the interfering association in multiple contexts without altering the number of interference trials during phase 2 increased retroactive cue interference (i.e., decreased responding consistent with the target association). The possibility of similar mechanisms underlying cue interference and outcome interference is discussed. 相似文献
15.
Rats were trained in a light ON vs light OFF discrimination in operant chambers with food reinforcement. Following acquisition, extinction under conditions of no alternations between S+ and S? and under conditions of numerous alternations between S+ and S? were examined. In Experiment I, extinction in S+ or S? alone produced less responding to S+ and more responding to S? than extinction with regular alternations between S+ and S?. In Experiment II, 9, 39, or 79 alternations in extinction between S+ and S? produced no differences in responding. These results indicate that during extinction of a discrimination there is (a) sharpening of differential performance, (b) a difference between multiple- and single-stimulus procedures, and (c) little effect of different numbers of alternations. 相似文献
16.
In three experiments, we examined how matching-to-sample by pigeons is affected by discrimination versus nondifferential training between the matching stimuli. In Experiment 1A, pigeons responding differentially to the sample stimuli off-baseline acquired accurate matching performances more rapidly than did pigeons responding nondifferentially to those same stimuli. In Experiment 1B, tests involving reversal of the off-baseline requirements demonstrated that the birds were primarily controlled in their matching choices by the sample stimuli. The results of Experiment 2 showed that off-baseline nondifferential training did not retard acquisition relative to comparable training between stimuli unrelated to the matching task. Together, these results suggest that discrimination training can facilitate matching acquisition by enhancing attention to the sample stimuli. 相似文献
17.
Douglas C. Brooks Matthew I. Palmatier Eliseo O. Garcia Jessica L. Johnson 《Learning & behavior》1999,27(1):77-88
The effect of an auditory cue presented during extinction on spontaneous recovery of a conditioned taste aversion was investigated in three experiments. Experiment 1 demonstrated that the presence of the cue during extinction did not influence saccharin consumption during that phase, and that an aversion to saccharin in the absence of the cue was stronger at 18 days than at 1 day after extinction, representing spontaneous recovery rather than a renewal effect. Experiment 2 showed that a cue presented during extinction and testing reduced spontaneous recovery. Experiment 3 replicated that effect and showed that it depended on the cue’s correlation with extinction and not on an unconditioned effect; cues that had been presented during or prior to conditioning did not reduce spontaneous recovery when presented during testing. The cue’s potential to reduce spontaneous recovery through conditioned inhibition or configural cue learning is discussed, as is the possibility that the cue retrieves a saccharin extinction memory in a manner consistent with Bouton’s (1993) account of spontaneous recovery. 相似文献
18.
Two experiments with human participants were used to investigate recovery of an extinguished learned response after a context change using ABC designs. In an ABC design, the context changes over the three successive stages of acquisition (context A), extinction (context B), and test (context C). In both experiments, we found reduced recovery in groups that had extinction in multiple contexts, and that the extinction contexts acquired inhibitory strength. These results confirm those of previous investigations, that multiple-context extinction can produce less response recovery than single-context extinction, and they also provide new evidence for the involvement of contextual inhibitory processes in extinction in humans. The foregoing results are broadly in line with a protection-from-extinction account of response recovery. Yet, despite the fact that we detected contextual inhibition, predictions based on protection-from-extinction were not fully reliable for the single- and multiple-context group differences that we observed in (1) rates of extinction and (2) the strength of context inhibition. Thus, although evidence was obtained for a protection-from-extinction account of response recovery, this account can not explain all of the data. 相似文献
19.
Dale Swartzentruber 《Learning & behavior》1993,21(1):14-22
Two autoshaping experiments with pigeons examined contextual control of responding to conditioned stimuli (CSs) when separate phases of reinforcement and nonreinforcement occurred in different contexts. In Experiment 1, a CS was first conditioned in Context A prior to nonreinforcement in Context B. In Experiment 2, a conditional discrimination reversal procedure was employed in which one CS was first reinforced in A prior to nonreinforcement in B, and another CS was first nonreinforced in A and then reinforced in B. In both experiments, the extent of contextual control was assessed by testing the CSs in A and B. The CS specificity of control was assessed by examining control of CSs that had been treated like the original CSs, but in a different pair of contexts. The results show that contexts control responding to CSs through a CS-specific mechanism, as well as through a mechanism that is independent of the identity of the CS. However, the extent to which control is mediated by a CS-independent mechanism depends on the training history of the CS. 相似文献
20.
Robert A. Rescorla 《Learning & behavior》1997,25(4):485-497
In six experiments, rats received discriminative training in which making a response (R) during a stimulus (S) produced a particular outcome (O). In Experiment 1, that outcome was replaced by a second outcome and responding was tested either immediately or after a delay. More substantial responding was observed with the delayed test. In Experiment 2, a test of transfer to new responses suggested that the growth in performance was not attributable to greater use of particular S-O associations. However, in Experiment 3, the growth in responding was found to be specific to particular S-R combinations. Experiment 4 replicated that specificity and demonstrated the importance of using two different outcomes for obtaining the growth in responding with time. Experiments 5 and 6 repeated these observations for the case of extinction, in which O was replaced by nonreinforcement. These results are interpreted as suggesting that an outcome-independent inhibitory S-R process develops, both with extinction and with the use of a second outcome, but dissipates with time. 相似文献