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1.
Sample and comparison location as factors in matching acquisition,transfer, and acquired equivalence
Urcuioli PJ 《Learning & behavior》2007,35(4):252-261
Pigeons learned symbolic matching with samples appearing equally often on left and right keys. For a location-relevant group,
the reinforced comparison choice for each sample reversed across sample locations; for a location-irrelevant group, the reinforced
choices were the same. Consistent with the hypothesis that samples at different locations are functionally different for pigeons,
Experiment 1 showed that matching acquisition was comparable in these two groups. Nevertheless, the location-irrelevant group
eventually ignored sample location, given that their performances subsequently transferred to a novel (center-key) sample
location. This transfer was not simply due to sample familiarity at different training locations; rather, it required that
left- and right-key samples occasion the same reinforced choices in training. Acquired equivalence between those samples was
then assessed in Experiment 2. The location-irrelevant group showed the predicted equivalence effects, but the location-relevant
group did not—in fact, its results were the opposite of those predicted by equivalence. Their results indicate that the functional
comparison stimuli are also defined in terms of their locations. 相似文献
2.
In Experiment 1, two groups of pigeons (n = 8) were given nondifferential (ND) training with a green keylight and a white vertical line on a dark surround nonsystematically alternated. Two groups (n = 8) received single stimulus (SS) training with the green light only. In Experiment 2, two groups of pigeons (n = 8) were given ND training with vertical and horizontal lines, while two other groups (n = 8) received SS training with only the vertical line. In both experiments, all groups were transferred to a green S+ (VI reinforced) and a red S? (extinguished) transfer problem. In each experiment, one ND and one SS group was tested in the same context as initial training (houselight off) and one ND and one SS group was tested in a changed context (houselight on). In both experiments and in both contexts, the ND groups performed less well on the transfer problem than did the SS groups. There was no evidence of greater control by the context in ND than in SS groups, which suggests that the observed difference in acquisition of the transfer task is not attributable to a purported difference in control by the context under the two conditions. The overall results favor the position that nondifferential training reduces attention to stimuli involved in the original training procedure and that this reduced attention transfers to stimuli subsequently experienced. 相似文献
3.
An attempt was madeto manipulate the strength of internal stimulus representations by exposing pigeons to brief delays between sample offset and comparison onset in a delayed conditional discrimination. In Experiment 1, pigeons were first trained on delayed conditional discrimination with either short (0.5-sec) delays or no delays. When delays were increased by 2.0 sec, birds trained with a delay performed at a higher level than did birds trained with no delays. In Experiment 2, subjects were first trained on a delayed simple discrimination. Following a circle stimulus, responses to a white key were reinforced; however, following a dot stimulus, responses to the white key were not reinforced. The pigeons were then trained on a delayed conditional discrimination involving hue samples and line-orientation comparisons with differential outcomes. Choice of vertical following red yielded food; choice of horizontal following green yielded no food. Mixed delays were then introduced to birds in Group Delay, whereas birds in the control group received overtraining. When tested on a delayed simple discrimination with hue stimuli (red and green initial stimuli followed by white response stimulus), pigeons in Group Delay tended to perform at a higher level than did birds in the control group (i.e., although the birds in both groups responded more following red than following green, birds in Group Delay did this to a greater extent than did birds in the control group). Thus, experience with delays appears to strengthen stimulus representations established during training. 相似文献
4.
David R. Thomas C. F. Hickis Raymond L. Jackson Robert J. Newlin 《Learning & behavior》1979,7(3):301-308
In Experiment 1, two groups (n = 10) of pigeons received 17 sessions of TD (true discrimination) or ND (nondifferential) training with line angles. Seventeen sessions of SS (single stimulus) training with a wavelength preceded this training and two followed it. Subsequent wavelength generalization testing in extinction revealed a sharper TD than ND gradient. This slope difference was evident from the very first test stimulus presentation and remained stable throughout testing. As a consequence of substantial overtraining, there was no reduction of response strength and no sharpening of generalization during testing for either group. In Experiment 2, two groups (n = 16) of pigeons received 10 sessions of TD or PD (pseudodiscrimination) training with line angles, followed by four sessions of SS training with a single wavelength. During this training and in subsequent wavelength generalization testing in extinction, brief blackouts separated stimulus presentations. Again, the TD group yielded the sharper gradient. Although responding weakened and the gradients sharpened during the test, these effects were comparable in the two groups. Furthermore, gradients based on the percentage of trials with at least one response showed the same TD-PD slope difference. This finding indicates that differential control over responding by response-produced feedback is inadequate to account for the TD-PD difference in generalization slope. Both experiments indicate that a purported difference in resistance to extinction is also an inadequate explanation. 相似文献
5.
Thomas R. Zentall Lou M. Sherburne Janice N. Steirn Christopher K. Randall Karen L. Roper Peter J. Urcuioli 《Learning & behavior》1992,20(4):373-381
Common coding in pigeons was examined using a delayed conditional discrimination in which each sample stimulus was associated with two different comparison stimuli (one-to-many mapping). In Experiment 1, pigeons matched circle and dot samples to red and green hues and vertical and horizontal line orientations. In Experiment 2, the samples were red and green and the comparisons were vertical and horizontal spatial positions (up vs. down and left vs. right). Following acquisition to high levels of accuracy in each experiment, the associations between the samples and either both sets or only one set of comparisons were reversed. Pigeons learned the total reversals faster than the partial reversals. These results suggest that when different comparisons are associated with a common sample, they may become functionally equivalent. 相似文献
6.
In Experiment 1, we used six procedures in a series of unsuccessful attempts to obtain relational learning using trial-unique pictorial stimuli in pigeons. The Experiment began by testing conventional (three-key) matching-to-sample (MTS) and nonmatching-to-sample (NMTS); in subsequent stages of the experiment we progressively incorporated features of techniques that do obtain relational learning in a single-key apparatus. In Experiment 2, we found that acquisition of NMTS using pictorial stimuli proceeded no more rapidly than acquisition of a conditional discrimination. Experiment 3 showed that acquisition of NMTS was more rapid than acquisition of MTS when plain colored stimuli were used, but not when pictorial stimuli were used. These three experiments suggest that pigeons do not recognize pictorial stimuli shown on different keys. In Experiment 4, between-key recognition was obtained with familiar but not with novel pictorial stimuli. It is argued that perceptual learning facilitates the detection of the between-key identity of complex stimuli, and that perceptual processes may underlie the difficulty in demonstrating relational learning in pigeons. 相似文献
7.
James V. Couch 《Learning & behavior》1975,3(4):347-358
Two experiments examined the presumed relationship between behavioral contrast and inhibitory stimulus control. In Experiment I, pigeons were exposed to mult VI 1-min VI 1-min or mult VI 5-min VI 5-min during baseline training prior to mult VI 1-min VI 5-min discrimination training. Half of the subjects received a timeout (TO) component during baseline in order to reduce the degree of contrast during discrimination training. Only 3 of 8 subjects receiving the TO showed contrast while all other subjects showed various degrees of contrast. Postdiscrimination generalization gradients indicated excitatory rather than inhibitory control by the stimulus associated with the VI 5-min schedule. During baseline training in Experiment II, responding to all the generalization stimuli was reinforced. In addition, some subjects received the TO stimulus. The subjects were next exposed to mult VI 1-min EXT, mult VI 1-min VI 5-min, or just the VI 5-min component. Generalization gradients indicated inhibitory control by the stimulus associated with EXT or VI 5-min for 19 of 20 subjects even though some subjects did not show contrast. These results question the presumed relationship between behavioral contrast and inhibitory stimulus control. 相似文献
8.
Peter J. Urcuioli 《Learning & behavior》1991,19(1):29-36
Pigeons were trained on many-to-one matching-to-sample with food and no-food outcomes that were either differential or nondifferential with respect to the sample stimuli. In the differential condition, outcomes were correlated with the correct comparison-alternatives-for half of the subjects, and were uncorrelated with those alternatives for the remaining subjects. Relative to non-differential training, matching acquisition was facilitated in the correlated condition but retarded in the uncorrelated condition. These results clearly demonstrate that differential outcomes do not affect conditional discrimination learning merely by enhancing the discriminability or distinctiveness of the samples with which they are associated. Rather, they apparently give rise to another discriminative cue (viz., an outcome expectancy), which can either enhance or interfere with performance, depending on its predictive validity. 相似文献
9.
Holly C. Miller Andrea M. Friedrich Randi J. Narkavic Thomas R. ZentAll 《Learning & behavior》2009,37(2):161-166
When differential outcomes follow correct responses to each of two comparison stimuli in matching to sample, relative to the
appropriate control condition, higher matching accuracy is typically found, especially when there is a delay between the sample
and the comparison stimuli. In two experiments, we examined whether this differential-outcomes effect depends on using outcomes
that differ in hedonic value (e.g., food vs. water). In Experiment 1, we found facilitated retention when a blue houselight
followed correct responses to one comparison stimulus and a white houselight followed correct responses to the other, prior
to nondifferential presentations of food. In Experiment 2, we found facilitated retention again when a blue houselight followed
correct responses to one comparison stimulus and a tone followed correct responses to the other, prior to nondifferential
presentations of food. The results of both experiments indicate that the differential-outcomes effect does not depend on a
difference in hedonic value of the differential outcomes, and they suggest that outcome anticipations consisting of relatively
arbitrary but differential stimulus representations can serve as cues for comparison choice. 相似文献
10.
Performance during simultaneous matching-to-sample was assessed in pigeons presented with element and compound visual samples. In Experiment 1, pigeons were trained with a symbolic matching procedure, in which different pairs of colored comparison cues presented on side keys were mapped onto a bright or dim houselight as one pair of sample stimuli and onto vertical and horizontal lines on the center key as a second pair of sample stimuli. They were then tested with houselight-line compound samples. It was found that matching accuracy for lines was significantly diminished with compound samples relative to element samples. Conversely, house-light intensities were matched as well with compound samples as with element samples. In Experiment 2, a similar effect was found with pigeons that had been trained to match only line samples. In Experiment 3, it was discovered that sample duration had no influence on the matching deficit found with lines following compound samples in birds either trained or not trained to match houselight intensities. These results, taken in combination with recent findings from experiments with auditory-visual compounds, suggest a restricted processing account of pigeon processing of simultaneously presented stimuli from different sources. 相似文献
11.
Patricia B. Cronin 《Learning & behavior》1980,8(3):352-358
Delayed-reward learning in pigeons was examined using a simultaneous red-green visual discrimination task in which the conditions during the delay interval were varied between groups. The nondifferential group received training in which the stimulus present during the 1-min delay was the same following a peck on the correct and incorrect colors. The other three groups received 1-min delay training in which different stimuli occurred in the delay interval following correct and incorrect choices. The differential group received continuous, differential stimuli during the delay. The reinstatement group received the differential stimuli in the 10 sec immediately following the choice and during the last 10 sec of the delay. The reversedcue group was treated in the same way, except that the 10-sec delay stimulus immediately following an incorrect response was also presented for 10 sec prior to reward on correct choices, and the stimulus following a correct response also occurred 10 sec before nonreward on incorrect choices. Nondifferential birds failed to learn the discrimination, while differential and reinstatement birds learned it readily. The reversed-cue birds learned to choose the incorrect stimulus. Differential and reinstatement birds showed no decrement in performance when the delay was increased to 2 min. These findings suggest that similarity of prereward and postresponse delay stimuli controls choice responding in long-delay learning, a finding compatible with both memorial and conditioned reinforcement interpretations. 相似文献
12.
After training with a variable-interval schedule of positive reinforcement, pigeons were tested for stimulus generalization along the hue dimension. For one group, the stimulus was located on the response key. For a second group, the stimulus was located on a surface adjacent to the response key. The stimulus-on-key group produced the typical steep gradients normally found with hue stimuli; the stimulus-off-key group produced flat gradients. After discrimination training between the presence and absence of the hue stimulus, both groups produced decremental gradients. In a second experiment, naive pigeons were trained to peck a transparent key with the stimulus surface located approximately 3.8 cm behind the key. When tested for generalization, the hue gradients were decremental. The results suggest that location of the stimulus in the line of sight with pecking is a necessary condition for stimulus control by hue after nondifferential training. 相似文献
13.
Donald M. Wilkie 《Learning & behavior》1986,14(3):257-266
In the delayed matching of key location procedure, pigeons must remember the location of the sample key in order to choose correctly between two comparison keys. The deleterious effect of short intertrial intervals on key location matching found in previous studies suggested that pigeons’ short-term spatial memory is affected by proactive interference. However, because a reward expectancy mechanism may account for the intertriai interval effect, additional research aimed at demonstrating proactive interference was warranted. In Experiment 1, matching accuracy did not decline from early to late trials within a session, a finding inconsistent with a proactive interference effect. In Experiment 2, evidence suggestive of proactive interference was found: Matching was more accurate when the locations that served as distractors and as samples were chosen from different sets. However, this effect could have been due to differences in task difficulty, and the results of the two subsequent experiments provided no evidence of proactive interference. In Experiment 3, the distractor on Trialn was either the location that had served as the sample on Trialn ? 1 or one that had been a sample on earlier trials. Matching accuracy was not inferior on the former type of trial. In Experiment 4, the stimuli that served as samples and distractors were taken from sets containing 2, 3, 5, or 9 locations. Matching accuracy was no worse, actually slightly better, with smaller memory set sizes. Overall, these findings suggested that pigeons’ memory for spatial location may be immune to proactive interference. However, when, in Experiment 5, an intratrial manipulation was used, clear evidence of proactive interference was found: Matching accuracy was considerably lower when the sample was preceded by the distractor for that trial than when it was preceded by the sample or by nothing. Possible reasons why interference was produced by intratrial but not intertrial manipulations are discussed, as are implications of these data for models of pigeons’ short-term spatial memory. 相似文献
14.
The effect of differential outcome expectancies on memory for temporal and nontemporal information was examined. Pigeons were trained to match short (2-sec) and long (8-sec) sample durations to red and green comparison stimuli, and vertical and horizontal lines to vertical and horizontal comparison stimuli. In Experiment 1, one differential outcome (DO) group received food for correct choices on short-sample trials, whereas another received food for correct choices on long-sample trials. On line-orientation trials, half of each DO group received food for correct responses following vertical samples, whereas the other half received food for correct responses following horizontal samples. Overall retention was greater in the DO groups than in a nondifferential (NDO) group that received either food or no food for correct responses on a random half of all trials. Furthermore, although the NDO group displayed a choose-short bias for temporal samples, both DO groups displayed equivalent biases to select the comparison stimulus associated with food. In Experiment 2, differential outcome expectancies were extinguished off-baseline. Subsequently, in the first nondifferential outcome test session, the. DO groups performed less, accurately than the NDO group. These findings indicate that temporal samples are not retrospectively and analogically coded when they are differentially associated with food and no food. Instead, they are remembered in terms of the corresponding outcome expectancies. 相似文献
15.
Two groups of pigeons were trained with a go/no-go procedure to discriminate video images of conspecifics based on the individuals or else on their actions. Both groups showed rapid acquisition, and the discrimination transferred to new scenes in Experiment 1 and to static scenes in Experiment 2. In Experiment 3, experimentally naive pigeons were trained to discriminate video images of particular birds showing different actions. Transfer to novel scenes, including a new bird and a new motion, revealed the dominance of motion as a cue to discriminate video images. In Experiment 4, the pigeons trained to discriminate video scenes of 2 pigeons showing a variety of activities successfully recognized these stimuli regardless of whether the video was played forward or backward, and transferred the discrimination to still scenes. The findings suggest that pigeons’ discrimination of video images is primarily based on information that is invariant across static and dynamic conditions. 相似文献
16.
Prior research has indicated that pigeons do not prefer an alternative that provides a sample (for matching to sample) over an alternative that does not provide a sample (i.e., there is no indication of which comparison stimulus is correct). However, Zentall and Stagner (Journal of Experimental Psychology. Animal Behavior Processes 36:506?C509, 2010) showed that when delay of reinforcement was controlled, pigeons had a strong preference for matching over pseudomatching (i.e., there was a sample, but it did not indicate which comparison stimulus was correct). Experiment 1 of the present study replicated and extended the results of the Zentall and Stagner (Journal of Experimental Psychology. Animal Behavior Processes 36:506?C509, 2010) study by including an identity relation between the sample and one of the comparison stimuli in both the matching and pseudomatching tasks. In Experiment 2, in which we asked whether the pigeons would still prefer matching if we equated the two tasks for probability of reinforcement, we found no systematic preference for matching over pseudomatching. Thus, it appears that in the absence of differential reinforcement, the information provided by a sample that signals which of the two comparison stimuli is correct is insufficient to produce a preference for that alternative. 相似文献
17.
In two experiments, rats solved two concurrent discrimination problems in which one stimulus (i.e., a facilitator) signaled the reinforcement of another stimulus (i.e., a target). Then a transfer test assessed the capacity of facilitators trained in one problem to promote responding to targets trained in the other. Experiment 1 found that a facilitator promoted as much responding to such a transfer target as to the target with which it was originally trained. Transfer was not obtained with a pseudofacilitator that was uninformative, in training, about the reinforcement of its target. Experiment 2 manipulated the stimulus modality of the targets and facilitators. Its results indicated that transfer performance was not due to generalization between training and transfer targets or facilitators. These results parallel those from comparable autoshaping paradigms with pigeons, and they agree with the view that facilitators promote responding by lowering the threshold for activation of the US representation. 相似文献
18.
In the present experiment, we investigated whether pigeons rely exclusively on elemental information or whether they are also able to exploit configural information in apeople-present/people-absent discrimination task. Six pigeons were trained in a go/no-go procedure to discriminate between 800 color photographs characterized by the presence or absence of people. Thepeople-present stimuli were designated as positive, and thepeople-absent stimuli were designated as negative. After training and a subsequent generalization test, the pigeons were presented with both familiar and novel people-present stimuli containing human figures that were distorted in one of seven different ways. All the pigeons learned the initial discrimination and also showed generalization to novel stimuli. In the subsequent test, performance on all types of distorted stimuli was diminished in comparison with that on the intact original pictures from which they had been derived. At the same time, however, peck rates clearly exceeded the level of responding found for regular people-absent stimuli. This result strongly suggests that responding was controlled by both the constituting target components and their spatial relations and, therefore, points to the dual importance of elemental and configural information. 相似文献
19.
In Experiment 1, 12 pigeons were given eight sessions of VI single stimulus training with a color in a particular context followed by eight sessions of similar training with a line angle in another context. On the next day, half of the subjects were tested for wavelength and angularity generalization in each of the two contexts, a procedure that was thus consistent with training for one dimension and inconsistent for the other. The subjects made significantly more responses to each training stimulus under the consistent context condition, but there was no difference in absolute or relative generalization slopes. In Experiment 2, 12 pigeons were trained as in Experiment 1, but during generalization testing they were exposed to both contexts sequentially. Under the consistent context condition, the subjects responded more to the two training stimuli and yielded sharper absolute and relative wavelength generalization gradients: Under the inconsistent context condition, responding to the training wavelength was substantially disrupted. Thus, under appropriate testing conditions, contextual control over both the amount and the selectivity of responding can be demonstrated. 相似文献
20.
The mapping of sample stimuli onto comparison stimuli and the nature of trial outcomes were factorially manipulated in a delayed matching-to-sample procedure. In the many-to-one condition (MTO), responding to a particular comparison was correct following several sample stimuli, whereas in the one-to-many condition (OTM), responding to several comparison stimuli was correct following a particular sample. Probabilities of reinforcement for correct responding to comparison stimuli were either differential (DO) or nondifferential (NDO). Four groups of pigeons were trained under four combinations of mapping and outcome conditions, MTO-DO, MTO-NDO, OTM-DO, and OTM-NDO. Testing at delay intervals of 1, 2, 4, and 8 sec revealed significant effects due to both the mapping variable and the differential outcomes variable. It was argued that the poorer performance obtained in the OTM condition was due to the differential prospective coding requirements placed on reference and working memory by this mapping. In the OTM conditions, a greater number of response codes had to be retrieved from reference memory and multiple response codes may have overburdened working memory, which has a limited capacity. 相似文献