共查询到20条相似文献，搜索用时 979 毫秒
1.
Three matching-to-sample experiments examined whether spatial or configural factors determined how the element arrangement of compound sample stimuli influenced matching accuracy in pigeons. Seven types of compound stimuli were tested. The arrangement of color and line-orientation elements in these compounds varied in terms of the spatial separation between the elements, the degree of consistency in element spatial location, and the number of bounded areas containing the elements. Matching accuracy was examined upon initial exposure to the compounds, during asymptotic conditions of shared attention, and with variation of sample durations ranging from .04 to 5.935 sec. In all three experiments, when spatial proximity, locational certainty, and the number of lines were precisely controlled or equated, no evidence for the proposed configural processing of “unified” compounds was found (Lamb & Riley, 1981). Element spatial separation, and to a lesser degree perceptual limitations, determined compound performance. These results question our lab’s previous evidence for configural compound processing by pigeons (Lamb, 1988; Lamb & Riley, 1981). They suggest instead that pigeons independently and separately process the individual elements of color/line-orientation compounds, with element separation determining the distribution of processing between the elements. 相似文献
2.
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
3.
Pigeons were trained to symbolically match comparison stimuli to either visual sample stimuli presented on a center key or to spatial sample stimuli presented on side keys. Tests were carried out in which visual and spatial cues were simultaneously presented in compound and short-term memory was probed for either visual or spatial information. Symmetrical interference with the matching of visual and spatial components of compounds was found when the visual and spatial cues were presented on separate keys. However, when visual and spatial cues were superimposed on the same side key, no interference was observed relative to element control tests. Discussion of these findings focuses on accounts in terms of limited processing capacity, coding decrement, and receptor orientation mechanisms. 相似文献
4.
Delayed conditional discriminations in which a sample indicates which comparison stimulus is correct have typically been used
in working memory research with animals. Following acquisition with no (0-sec) delay between the offset of the sample and
the onset of the comparison stimuli, delays of variable duration are introduced. The resulting retention functions are taken
as a measure of memory. We suggest that, in addition to memory loss due to the delay, the comparison of matching accuracy
at the 0-sec training delay with relatively novel test delays may produce a generalization decrement that varies as a function
of increasing delay. We tested this hypothesis by training pigeons with a mixed delay procedure from the start and found that
the retention functions for these pigeons were significantly shallower than those for a control group trained with 0-sec delays
and tested with longer delays, and, although reduced in magnitude, the differences persisted for as many as 15 sessions. We
propose that a measure of animals’ working memory can be obtained uninfluenced by a generalization decrement if they have
received comparable training with all of the delays that are tested. 相似文献
5.
Thomas R. Zentall Peter J. Urcuioli Joyce A. Jagielo Pamela Jackson-Smith 《Learning & behavior》1989,17(2):172-178
Coding strategies developed in the acquisition of delayed conditional discriminations can be assessed by independently manipulating sample and comparison memory load. Two stimulus dimensions that can affect memory load were examined: Number of stimuli in the sample and comparison sets (two vs. four) was manipulated between groups in a 2×2 design, and discriminability of sample and comparison stimuli (hues vs. lines) was manipulated between counterbalancing subgroups and within subjects. The results indicated large effects of sample discriminability but not of comparison discriminability, evidence for retrospective coding. There was also a significant effect of number of stimuli in the comparison set (although only with hard-to-discriminate samples) but not of number of stimuli in the sample set, evidence for prospective coding. These findings suggest evidence for retrospective coding with easy-to-discriminate samples, independently of number of stimuli in the comparison set, and evidence for prospective coding with hard-to-discriminate samples. 相似文献
6.
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
7.
Previously, we have shown that changes in pigeons’ divided attention performance resulting from changes in relative reinforcement
are well described by the generalized matching law. In the present experiment, we examined whether sensitivity of performance
to variations in relative reinforcement would be dependent upon sample duration. Pigeons responded on a delayed matching-to-sample
procedure with compound samples (color 1 line orientation) and element comparison stimuli (two colors or two line orientations).
Relative reinforcement for accurate matches on the two types of comparison trials varied across conditions. Sample duration
was short (i.e., 0.75 sec) for half of the trials in a session and longer (i.e., 2.25 sec) for the other half. Sensitivity
of accuracy to changes in relative reinforcement was greater with the longer sample than with the shorter sample, suggesting
that differential reinforcement alters the allocation of attending to the elements of compound stimuli. Continued examination
of the applicability of well-established theories of goal-directed behavior to the allocation of attention may provide further
insights into what is variously referred to as goal-directed, voluntary, endogenous, or top-down control of attention. 相似文献
8.
Two experiments were performed to determine the effects of omitting the comparison stimuli in a matching-to-sample task. In Experiment 1, birds were trained initially on both symbolic and identity matching to sample. Comparison stimuli were then omitted following the presentation of a particular sample stimulus, and this decreased the number of sample (observing) responses. The reintroduction of the comparison stimuli on subsequent probe trials revealed that the accuracy of symbolic matching was reduced to chance levels, while identity matching accuracy was significantly below chance. In Experiment 2, a similar procedure was employed; however, observing responses to the comparison-omitted samples were maintained by direct reinforcement (fixed ratio 20). Matching accuracy during probe trials was again at chance levels for symbolic matching but, contrary to Experiment 1, was significantly above chance for identity matching. The differential effects of omitting comparison stimuli on symbolic and identity matching trials in these two experiments were interpreted within a framework which assumes that instructional processes are altered by comparison-omission procedures. 相似文献
9.
A bottlenosed dolphin (Tursiops truncatus) with good underwater and aerial visual acuity was tested in visual matching-to-sample (MTS) paradigms. Attempts to train visual identity MTS directly, using two simple two-dimensional patterns as sample stimuli and as alternatives (comparison stimuli), met with little success, in keeping with previously observed difficulties of this auditory-specialized species for learning complex tasks utilizing simple visual materials. Pairing of each visual sample with a unique sound, to produce a compound auditory-visual sample, while retaining the two visual alternatives, resulted in the dolphin’s learning both auditory-visual symbolic matching and visual-visual identity matching. At 0-sec delay, performance with the auditory element of the sample alone was equivalent (76%) to performance with the visual element alone; performance with the compound was distinctly better (95%–98% correct). Testing with longer delays using the visual element alone resulted in successful matching through to a maximum delay of 34 sec. These results provided the first demonstration of delayed MTS in a dolphin using visual materials, and complemented other data showing the ready capability of this species for delayedauditory MTS. It appeared that the dolphin solved the visual MTS task by forming auditory codes to represent the visual materials, and that these auditory codes were eventually replaced with purely visual codes. 相似文献
10.
William S. Maki 《Learning & behavior》1979,7(1):31-37
Pigeons performed a delayed matching-to-sample task in which they matched red and green disks as comparison stimuli to samples of food and no food. The birds were also taught a discrimination between two lines: vertical (S+) followed by food and horizontal (S?) followed by no food. The two kinds of trials were then chained in infrequent probes such that (a) S+ and S? preceded samples of food and no food, (b) a longer than usual delay occurred, and then, (c) the comparison stimuli were presented. Therefore, in probes when S+ preceded food and S? preceded no food, the samples were “expected. ” But in probes when S+ signaled no food and S? signaled food, the samples were “surprising. ” Matching to surprising samples was more accurate than matching to expected samples. This result completes a pattern of findings implying that surprising reinforcers enhance learning and also persist (are longer rehearsed) in short-term memory. 相似文献
11.
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
12.
Models of associative learning differ in their predictions concerning the symmetry of generalization decrements. Whereas Pearce’s
(1994) configural model predicts the same response decrement after adding elements to and after removing elements from a previously
trained stimulus, elemental models, such as the replaced elements model and Harris’s (2006) model, anticipate more of a decrement
for removing than for adding elements. In three contingency learning experiments, we manipulated the motion and the spatial
arrangement of colored dots in order to induce configural or elemental processing by perceptual grouping. The results reliably
showed symmetrical decrements for the added and removed groups. The manipulations of the stimuli had no effect on stimulus processing. This is in line with Pearce’s configural model,
but it is at variance with the elemental models and previous studies. 相似文献
13.
In three experiments, rats were given concurrent exposure to a compound flavor (AX) and to one of the elements of the compound
(X). The perceptual effectiveness of A was then assessed by a test involving generalization of a conditioned aversion. Comparison
was made with a preexposure procedure in which the compound and the common element were presented on separate trials, either
in alternation or in separate blocks of trials. The effectiveness of the unique cue was less after blocked preexposure than
after either of the other procedures; concurrent preexposure did not produce a greater effect than did alternating preexposure.
These results challenge the suggestion that concurrent preexposure engages a special comparison process that will facilitate
this form of perceptual learning. 相似文献
14.
Animals perform two-choice conditional discriminations at a higher level if each of the two correct responses to the comparison stimuli is reinforced with a different outcome. According to the two-process view, this differential outcomes effect (DOE) results from the response-cuing function of expectancies generated by the conditional stimuli (i.e., samples). According to the shared-outcomes view, differential response-outcome associations contribute to the effect. In the present research, pigeons that were trained with differential outcomes associated with the samples, butnot with the comparisons, revealed a DOE during delay testing that was comparable to that obtained in a “true” differential-outcomes group. Thus, a two-process interpretation of the DOE was supported. In the second experiment, transfer testing with sample replacement confirmed these findings and, in addition, provided evidence that differential sample behaviors exerted some control over zero-delayed choice. 相似文献
15.
Rescorla RA 《Learning & behavior》2007,35(1):19-26
Four magazine approach experiments were performed with rats to explore the decrement produced by reinforcing a compound of two previously conditioned stimuli. Compound presentation produced the usual over-expectation decrement in responding to the individual stimuli. However, testing in an alternative, but similarly treated, context allowed renewal of the initial responding to the individual stimuli. This renewal is similar to that seen after a decrement produced by nonreinforcement. It joins other results in suggesting that the decrement produced in extinction and overexpectation may be due to the same mechanism. 相似文献
16.
Batsell WR Wakefield E Ulrey LA Reimink K Rowe SL Dexheimer S 《Learning & behavior》2012,40(2):180-194
The present series of five flavor aversion experiments with rat subjects examined compound conditioning at varying CS-US intervals. Using a taste-taste design, Experiments 1A and 1B demonstrated overshadowing at a 0-min CS-US interval and potentiation at a 120-min CS-US interval, and these effects occurred with both tastes of the compound. Experiment 2 showed that the aversion to a single element is reduced when the CS-US interval is increased to 120 min, but the aversion for a compound taste is not. Experiments 3A and 3B explored odor + taste compound conditioning; the results demonstrated odor potentiation across the trace interval and a transition from taste overshadowing to taste potentiation. Collectively, the data show that the change from overshadowing to potentiation was not due to changes in the aversions produced by compound conditioning but, instead, was due to a more rapid loss of conditionability across a trace interval prior to the US in single-element conditioning. These experiments suggest that following compound conditioning, the aversion to each element represents generalization decrement from the configured compound, but the designation of overshadowing or potentiation actually depends on the status of conditioning in the single-element control. 相似文献
17.
In two experiments using the taste-aversion paradigm, we attempted to replicate a result reported by Holland and Forbes (1980), in which exposure to the elements of a compound produced more interference with future conditioning (latent inhibition) to the compound than did exposure to the compound itself. In our first experiment, a compound of HC1 and sucrose was used and the amount of fluid consumed during exposure and the first conditioning trial was controlled. Rather than finding enhanced interference produced by exposure to the elements, we found reduced interference relative to exposure to the compound. In Experiment 2, a compound of NaCl and sucrose was used and a method similar to that used by Holland and Forbes was employed. We replicated the result of our Experiment 1. We interpret these results as posing problems for some associative accounts of latent inhibition but as being easily explained as an instance of stimulus generalization decrement. 相似文献
18.
Two pigeons were trained on a six-key modified oddity-from-sample procedure. The stimuli were olor pictures of birds, butterflies, and human faces. Initially, the third peck on the sample key which presented one of three different bird pictures) lit only one comparison key. Every three dditional pecks on the sample illuminated another comparison key. Fifteen sample pecks produced he maximum of five comparison stimuli. A peck on the comparison key that presented the non-atching bird picture produced grain. Pecks on matching keys turned off all the comparison keys nd repeated the trial. The birds learned to peck each sample until the non-matching comparison timulus was produced, and then to peck that key. After acquisition (70%–90% accuracy), the hree bird stimuli were replaced by a new set of three bird pictures. Subsequent phases provided ew sets of bird, butterfly, and human face stimuli. Both birds showed transfer of oddity learning o the novel samples. The data suggest that the birds may have been engaging in conceptual-type oddity learning, rather than learning discrete five-key discriminations or a series of two component chains. 相似文献
19.
Peter J. Urcuioli 《Learning & behavior》1984,12(3):256-264
Separate groups of pigeons were trained to high levels of accuracy on 0-delay matching-to-sample with sample-response requirements that were either differential or nondifferential with respect to the sample stimuli. Differential subjects produced the comparisons by completing a differential-reinforcement-of-low-rates-of-responding 3-sec (DRL 3″) requirement during one sample and a fixed-ratio (FR 10) requirement during the other. Nondifferential subjects produced the comparisons by completing the same schedule requirement (either DRL 3″ or FR 10) for both samples. Following acquisition to criterion, the DRL and/or FR sample-response requirements were replaced by a nondifferential single-peck (CRF) requirement in order to assess the degree to which the samples had acquired control over choice in each group. This change disrupted performance in all subjects, but the disruption was greater for the differential birds, which generally performed at lower levels of accuracy and required more sessions of retraining to reach criterion levels of accuracy than the nondifferential birds. Follow-up experiments revealed that comparison choices by the differential birds were primarily controlled by their DRL vs. FR sample-specific behaviors. The relatively poor performance of the differential group during testing with CRF requirements suggests that the cue arising from the birds’ differential sample behaviorshad also overshadowed the sample stimuli for conditional control over choice. The unique, and rather unusual, aspect of this overshadowing effect is that it occurred in spite of the fact that the overshadowed cue (that provided by the samples) was necessary for producing the cue that resulted in overshadowing (the differential sample behaviors). This finding has potentially important implications for the differential outcomes effect in conditional discrimination learning and for attentional processes in compound-cue situations in general. 相似文献
20.
We examined the extent to which nonhedonically different differential outcomes involving feeder location control pigeons’
comparison choices in matching to sample. In Experiment 1, we showed that differential feeder location outcomes associated
with each of two samples can facilitate delayed-matching accuracy. In Experiment 2, we found positive transfer following training
on two matching tasks with differential feeder location outcomes when samples from one task were replaced by samples from
the other task. In Experiment 3, we found that when differential-outcome expectations could no longer serve as the cues for
comparison choice, sample stimuli continued to exert some control over choice of comparisons. The results indicate that differential
outcomes (involving feeder location) that presumably do not differ in hedonic value are sufficient to control comparison choice.
Thus, the differential hedonic value of the outcome elicited by the sample does not appear to be a requirement of the differential-outcome
effect. Furthermore, these differential outcomes appear to augment matching accuracy, but they do not eliminate control by
the samples. 相似文献