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1.
A transfer of control experiment measured the associative properties of contextual stimuli from three standard classical conditioning paradigms. After baseline training on a Sidman avoidance schedule, dogs received aversive conditioning using excitatory, inhibitory, or truly random conditioning procedures in the presence of a manipulable background stimulus. As predicted by current theory (Rescorla & Wagner, 1972; Wagner & Rescorla, 1972), the contextual stimulus was excitatory after serving as the background during conditioning of a CS? and was neutral when it had been part of the background for conditioning of a CS+. The background to the truly random procedure was also neutral. This last result contrasts with Rescorla and Wagner’s theory. 相似文献
2.
Rats were subjected to the Kamin two-stage blocking procedure. First, a stimulus, A, was conditioned and then reinforced in compound with a target stimulus, B. During compound training, an attempt was made to alleviate blocking of conditioning to B by presenting a “surprise” stimulus for 5 sec following the reinforced AB compound. The surprise stimulus consisted of the continued presentation of the previously reinforced element, A. During A training, A had never extended beyond the moment of reinforcement; thus, its extension beyond reinforcement during AB training was hypothesized to be “surprising” and, therefore, expected to alleviate blocking. Blocking in this condition was, however, just as strong as in a standard blocking condition. The results do not favor a surprise interpretation of unblocking but do seem to be consistent with other theoretical views (e.g., Rescorla & Wagner, 1972). 相似文献
3.
In three between-groups blocking experiments with rats, two concurrent and one forward, several common control procedures
were employed: Reinforced trials with the putative blocking stimulus were either omitted entirely (Kamin control), replaced
by unsignaled reinforcements (Wagner control), or replaced by reinforced trials with a different stimulus (C1 control). In
each experiment, parallel treatments with the target stimulus absent during training served to examine the possibility that
differential responding in tests with the target stimulus might be traced solely to differential exposure to the nontarget
stimuli. In Experiment 1, responding by a concurrent blocking group during the test was no different than responding by a
Kamin control group, and responding by a Wagner control group was greater than that of either of the other groups—a pattern
of results, mirrored in the performance of the target-absent groups, that could be attributed to the elevation of contextual
excitation by unsignaled reinforcement. In Experiment 2, responding in the test by a concurrent blocking group was no different
than that by a C1 control group. In Experiment 3, a finding of less responding by a forward blocking group than by a C1 control
group when the target stimulus was present during training, but not when it was absent, provided plausible evidence of blocking. 相似文献
4.
Blocking of conditioned suppression in rats was studied in three experiments using serial and simultaneous compounds in Pavlovian trace conditioning procedures. Experimental groups were first given trace conditioning trials with a 2-sec stimulus (A) presented at least 60 sec before an electric grid shock US. Next, both experimental and control groups received reinforced trials with a compound stimulus (AB). Both A and B were 2 sec in duration and were presented at least 60 sec before the US. For some groups during AB training, the A stimulus preceded the B stimulus; for others, B preceded A; for still others, A and B occurred simultaneously. Conditioning was subsequently assessed separately to both A and B. The results were as follows: First, varying the interval between the onset of A and the US during A training appeared to produce significantly different levels of conditioning to A but did not detectably affect A’s ability to block conditioning to B. Second, blocking was observed in both simultaneous and serial procedures. Third, in the serial procedure, A blocked conditioning to B whether it preceded B or followed B in the AB compound. Fourth, in tests given after AB conditioning, the experimental and control groups suppressed similarly to A. The relevance of these results to the conditioning model of Rescorla and Wagner (1972) and to Mackintosh’s (1975b) theory of attention are discussed. 相似文献
5.
A classical conditioning procedure was instituted in which the locus of the US was changed coincidentally with the onset of the compound conditioning phase of the Kamin blocking design. The nictitating membrane of the rabbit served as the conditioning preparation. Three groups of nine rabbits each were employed: a conventional blocking group in which the US was unchanged during the simple and compound conditioning phases, a control group that received only the compound conditioning phase, and an experimental group given both simple and compound conditioning but in which the US was administered to the contralateral paraorbital region during the compound conditioning phase. Postconditioning presentations of the elements of the compound CS indicated that, relative to the control group, responding during the new element was markedly reduced in the conventional blocking group but was strongly conditioned in the group in which the US locus was changed. Implications of these findings for theoretical analyses of conditioning are discussed. 相似文献
6.
Three experiments showed a savings procedure to be an effective and sensitive alternative to sensory preconditioning procedures as a measure of associations among neutral stimuli. Experiment 1 showed that within-compound associations developed more rapidly in reinforced appetitive serial compound conditioning when nonreinforced preexposure to the serial compound was given than when separate element or no preexposure was given. Experiment 2 showed the savings effect to be highly stimulus specific. Experiment 3 examined the facilitation of serial compound conditioning after either simultaneous or serial nonreinforced preexposure to the elements of the compound. The results of that experiment were consistent with those of analogous sensory preconditioning experiments. When preexposure involved only the two elements of the subsequently reinforced compound, serial preexposure produced more savings than simultaneous preexposure. But when preexposure involved a three-stimulus procedure like that used by Rescorla (1980b), simultaneous preexposure resulted in more savings. Advantages of the savings procedure over sensory preconditioning as a measure of association among neutral stimuli are discussed. 相似文献
7.
A variant of the taste aversion procedure for sensory preconditioning, as used by Rescorla and Cunningham (1978), was employed in a study of the context dependency of within-event learning. In two experiments, rats received Phase 1 exposure to a simultaneous flavor compound, AX; flavor X was paired with illness during Phase 2, and any tendency for the resulting aversion to be elicited by A was measured. It was found that subjects were less likely to shun flavor A as a consequence of this training if the Phase 1 and test episodes were conducted in distinctively different contexts. This effect was evident both when the change of context occurred just before the test with flavor A (Experiment 1) and when it occurred before Phase 2 (Experiment 2). These results were taken to imply that, as is often found with serial associations, the retrieval of within-event associations is subject to contextual control. The implications of these findings for the interpretation of perceptual learning effects are discussed. 相似文献
8.
Experiment I demonstrated shuttlebox avoidance conditioning using intense white noise as a UCS. Ten rats were given 25 trials a day for 6 days. Escape latencies declined and avoidance responses increased over trial blocks. Experiment II provided support for a functional similarity between shock as a UCS and intense noise as a UCS by demonstrating the Kamin effect following incomplete shuttlebox training to noise. Separate groups of rats were given 25 trials followed by an additional 25 trials either 0, 1, 4, or 24 h later. The U-shaped Kamin effect was evident in the avoidance measure. A similar but inverted U-shaped function was obtained for the escape latency measure. Escape latencies were longer on retraining than on original training at 1 h but not at 0, 4, or 24 h after original training. 相似文献
9.
Water-deprived adult rats were used in a conditioned-suppression-of-licking procedure to determine the effect of inhibitory training with a novel stimulus trained in simultaneous compound with a previously established conditioned inhibitor. This procedure constitutes an inhibitory analogue to the excitatory blocking procedure in classical conditioning. The conditioned-inhibition training consisted of either explicitly unpaired CS and US presentations or negative contingency training, in which the likelihood of the US was greater in the absence than in the presence of the CS, but the CS and the US were occasionally paired. To assess conditioned inhibition, a retardation test was used, and comparable retardation was obtained for subjects that were administered the blocking treatment and control subjects given similar conditioned-inhibition training with a compound stimulus in which the nontarget element was not previously established as a conditioned inhibitor. 相似文献
10.
Although a number of studies have demonstrated nearly complete retention of fear in a conditioned suppression task, they provide little information about the nature of the memory for the CS. The purpose of the present experiment was to investigate the retention of an attribute of a tonal CS that had been paired with shock and was thus capable of eliciting a conditioned emotional response (CER) in rats. The Kamin blocking effect was utilized to detect changes in the memory of CS attributes. Either 1 or 21 days following conditioning to a tone, separate groups of rats received compound conditioning in which either the original or a novel tone was combined with a light. Subsequent measurement of suppression to the added element (light) indicated that only the original CS produced blocking at the short delay, but that both original and novel tones resulted in blocking at the 21-day interval. This increase in the extent of blocking suggests that memory for specific attributes of the CS does diminish as a function of time. 相似文献
11.
Extinction-induced attenuation of single-phase and two-phase blocking was examined with rats in a conditioned lick-suppression
task. In Experiment 1, which compared the effectiveness of single- and two-phase blocking, it was found that single-phase
blocking was facilitated by the initiation of training with an A-US trial rather than an AX-US trial. Single-phase (but not
two-phase) blocking was attenuated as a result of 200 extinction trials with the blocking stimulus (Experiment 2). Experiment
3 revealed recovery from two-phase blocking after 800 extinction trials with the blocking stimulus. Recovery from both types
of blocking was specific to the blocked CS trained in compound with the extinguished stimulus (Experiment 4). This is the
first article to report that the blocking deficit can be reversed by extinguishing the blocking stimulus. These results are
discussed in light of acquisition models (i.e., retrospective revaluation) and expression models (i.e., the comparator hypothesis). 相似文献
12.
Pigeons were trained to depress a treadle in the presence of a discriminative stimulus, either a tone or illumination of red houselights, in order to obtain access to grain or avoid electric shock. In avoidance training, the auditory discriminative stimulus yielded faster acquisition than did the visual one. In appetitive training, the visual discriminative stimulus yielded faster acquisition than the auditory one. Experiments 2 and 3 used these stimuli in Kamin’s (1969) blocking design. In Experiment 2, when the pigeons were trained to depress a treadle in the presence of tone to obtain grain and then red light was added as the redundant stimulus, the light acquired stimulus control over treadlepressing; blocking was not observed. In Experiment 3, when the pigeons were trained to depress a treadle in the presence of red light to avoid electric shock and then tone was added as the redundant stimulus, the tone acquired stimulus control over treadle-pressing. Again, blocking was not observed. The implications of these results for several models of stimulus control are discussed. 相似文献
13.
A series of experiments was conducted to examine the phenomenon of potentiation. Experiment 1 demonstrated potentiation of odor aversions by taste when morphine served as the unconditioned stimulus (US). Experiment 2 provided evidence that the observed potentiation was due to a within-event association between odor and taste stimuli, rather than reflecting an enhanced odor-morphine association. In Experiment 3, morphine supported place conditioning to contextual cues and aversive conditioning to a taste cue, but potentiation of place conditioning by a taste cue was not obtained. Apparently the absence of potentiation was due to the dual nature of the morphine US, as potentiation of a contextual aversion by taste was obtained in Experiment 4 when a strictly aversive US (lithium) was used. These data suggest that potentiation depends on (1) an initially weak association between the to-be-potentiated conditioned stimulus (CS) element and the US, and (2) the elicitation of qualitatively similar responses by the individual elements of the CS compound. Collectively, these results support an explanation of potentiation based on within-event learning. 相似文献
14.
Three experiments on classical differential conditioning of the human skin conductance response to elemental and compound stimuli are reported. Subjects in Experiment 1 received both positive and negative patterning training, followed by either positive or negative patterning transfer tests on new stimuli. In positive patterning, a compound of two stimuli is reinforced and its elements are nonreinforced. In negative patterning, the elements are reinforced and the compound is nonreinforced. Subjects in Experiments 2 and 3 received either positive or negative patterning during training, followed by transfer tests on new stimuli. In Experiment 2, the transfer series began with new elements, after which their compound was presented; in Experiment 3, the new compound was presented first in the transfer series, and then the separate elements were administered. All three experiments provided evidence of the acquisition of positive patterning, while negative patterning was found only in Experiments 2 and 3. Positive patterning transferred to new stimuli, indicating that it was not attributable solely to summation of sub-threshold excitation conditioned to the elements on reinforced compound trials. This finding, coupled with the negative patterning found in Experiments 2 and 3, provided support for the unique cue hypothesis. It was concluded that the assumed unique cue constituted a learned “rule,” and that the actual elemental stimuli were neither perceptually nor otherwise modified during the conditioning process. 相似文献
15.
Alexander F. Luongo 《Learning & behavior》1976,4(3):225-230
In three experiments, rats were presented compound solutions consisting of a common element, saccharin, mixed with one of two different flavor elements, cinnamon and wintergreen. Rats in the experimental groups consistently received a toxicosis-inducing injection following one compound solution but not following the other compound solution. Rats in the control groups received toxicosis-inducing injections half the time following each of the compound solutions. After training in each experiment, there were tests for conditioning to the saccharin alone. The experimental groups drank significantly more than the control groups, indicating that the aversion to the partially reinforced saccharin in isolation was less when the different flavor cues were more highly correlated with reinforcement. In Experiment III, there was also a test for conditioning to the cinnamon or wintergreen flavor alone. The experimental group drank significantly less of the continuously reinforced flavor than the control group did of the partially reinforced flavor. These results are similar to those reported within more traditional conditioning paradigms. 相似文献
16.
Three experiments tested whether events taking place before a rat has access to a target taste, sucrose, can proactively interfere with the acquisition of a sucrose aversion when sucrose is followed by a lithium chloride injection. Using a serial overshadowing procedure with various delays before lithium injection, proactive interference by a taste (Experiments 1 and 3) and by a novel context (Experiment 2) was found following two conditioning sessions, but not after a single conditioning session. Conversely, overshadowing by a taste given after the target was detectable after a single conditioning trial (Experiment 3) and, thus, indicated that retroactive interference involves a process different from that producing proactive interference. A simulation confirmed that the results are consistent with a modified Rescorla and Wagner (1972) interpretation of Revusky??s (1971) concurrent interference theory of delay learning. 相似文献
17.
In an experiment on conditioned suppression of licking in thirsty rats, subjects received either one or two trials to a tone-light compound, either preceded or not preceded by four conditioning trials to the light alone. Prior conditioning to the light blocked conditioning to the tone in subjects receiving two compound trials but not in those receiving only one compound trial. The blocking observed in the two-trial groups was abolished either by the addition of an unexpected second posttrial shock 10 sec after the first on each compound trial or by the omission of an expected second, posttrial shock. The comparable operations had no effect on conditioning to the tone in the one-trial group. In this preparation, both blocking and the attenuation of blocking by surprising changes in reinforcement appear to require more than one trial to appear. 相似文献
18.
Chana K. Akins 《Learning & behavior》1998,26(4):416-426
Three experiments were conducted to investigate direct and modulatory influences of context in the conditioned sexual behavior of male Japanese quail. A preference test procedure was used to assess the acquisition of contextual excitation. In Experiment 1, following direct context-unconditioned stimulus (US) pairings, male quail shifted their contextual preference from an initially preferred context to one in which they received copulatory opportunity with a female quail (US). Unpaired control group subjects did not demonstrate this shift in preference. This place preference procedure was used in Experiments 2 and 3 to assess contextual excitation when context was trained in the presence of a discrete conditioned stimulus (CS). Experiment 2 provided evidence that context can modulate responding to a discrete CS. In Experiment 3, we varied the spatial contiguity between the context and the US. Some subjects received the US directly in the training context, whereas other subjects received the US in an alternate context. Contextual excitation was evident only in subjects that received the former. Thus, there is a dissociation between the modulatory and excitatory properties of context in sexual conditioning that may depend on the context-US spatial contiguity. 相似文献
19.
Alba E. Mustaca Fabian Gabelli Mauricio R. Papini Peter Balsam 《Learning & behavior》1991,19(2):125-138
Appetitive contextual conditioning in rats and ringdoves was investigated in six experiments. In Experiment 1, differential contextual training produced greater anticipatory activity in rats in the presence of a context paired with food than it did in rats in the presence of a different context in which food was never presented. Furthermore, the rats showed a preference for the context associated with food when they were given a simultaneous choice test between contexts. In Experiment 2, rats were more active in and preferred a context associated with a variable-time 30-sec (VT30) schedule as opposed to a VT180 schedule. Experiment 3 was a between-subjects replication of the previous experiment. As expected, rats exhibited significantly more anticipatory activity in a context in which food had been presented on a VT30 schedule than they did in a context in which food had been presented on a VT180 schedule. Experiment 4 showed that anticipatory activity was a reflection of context-US associations in ringdoves, and in Experiments 5 and 6, ringdoves also exhibited an inverse relationship between the. amount of anticipatory activity and the length of the interreinforcement interval (IRI). These results reveal a relation between ERI and contextual conditioning opposite from that obtained in studies of aversive conditioning. 相似文献
20.
Two conditioned lick suppression experiments with rats used feature-negative training (A-footshock trials intermixed with
nonreinforced XA presentations) to analyze the role of the number of XA compound presentations and the temporal relationship
of the elements within the compound (simultaneous or serial) as determinants of the resulting behavioral control. Second-order
conditioning (i.e., excitatory behavioral control by X) was observed to decline as the number of XA compound trials was increased.
This decline was more rapid if X and A were presented simultaneously, as opposed to serially (i.e., X before A; Experiment
1). Conditioned inhibition to X, as assessed by a summation test (Experiment 1) and a retardation test (Experiment 2), increased
with the number of XA trials and did so more quickly for simultaneous than for serial pairings of X and A. The results help
to clarify previously discrepant findings regarding factors that promote excitation versus inhibition with this protocol. 相似文献