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1.
Only a limited number of species have been found capable of generalized matching-to-sample (MTS) after exposure to relatively few training exemplars. We trained a juvenile, experimentally naive California sea lion (Zalophus californianus) in MTS, using a pair of three-dimensional objects as samples. Successful matching to a criterion of 90% correct or better over 2 successive sessions was attained in 12 sessions (269 trials and 70 errors). Two subsequent “partial” transfer tests, in which each of the two training objects was paired with a novel test object, and four additional transfer tests, all with novel objects, were presented following training. An 80% performance criterion over 2 successive sessions was reached, or closely approximated, in from 2 to 4 transfer sessions for all transfer tests; errors to criterion tended to be reduced across the successive novel transfer tests and were as few as five during the final two tests; and performance on the first 48 trials of the last two novel transfers was not significantly different from a near-ceiling level baseline performance measure. Neophobic responses of the sea lion to new objects precluded an unbiased evaluation of immediate (Trial 1) transfer. The sea lion’s short-term memory for sample objects was also measured. Matching performance was maintained at a level of 78% correct responses or better for delays through to 45 sec after removal of the sample object. At a 58-sec delay, the longest tested, performance declined to 69% correct responses. These retention levels are only somewhat below levels reported for dolphins and nonhuman primates tested on visual delayed MTS, but they are above levels typically reported for pigeon subjects. 相似文献
2.
Kelling AS Snyder RJ Marr MJ Bloomsmith MA Gardner W Maple TL 《Learning & behavior》2006,34(2):154-161
Hue discrimination abilities of giant pandas were tested, controlling for brightness. Subjects were 2 adult giant pandas (1
male and 1 female). A simultaneous discrimination procedure without correction was used. In five tasks, white, black, and
five saturations each of green, blue, and red served as positive stimuli that were paired with one or two comparison stimuli
consisting of 16 saturations of gray. To demonstrate discrimination, the subjects were required to choose the positive stimulus
in 16 of 20 trials (80% correct) for three consecutive sessions. Both subjects reached criterion for green and red. The female
subject also reached criterion for blue. The male was not tested for blue. This study is a systematic replication of Bacon
and Burghardt’s (1976) color discrimination experiment on black bears. The results suggest that color vision in the giant
panda is comparable to that of black bears and other carnivores that are not strictly nocturnal. 相似文献
3.
In Experiment 1, six groups of pigeons (n=8) were tested for wavelength generalization either immediately or 24 h after learning a successive discrimination, with 550 nm reinforced and a black vertical line extinguished. The groups differed in the stimulus present during single stimulus pretraining, which was 550 nm (pretrain S+), the vertical Une (pretrain S?), or a neutral dim white light (pretrain Sn), respectively. The three immediate generalization gradients were steep and indistinguishable, reflecting only the immediately preceding discrimination training condition. The three delay gradients were flatter, with the flattening particularly marked in the pretrain S? group. This was interpreted as proactive interference (PI) resulting from the memory that both the 550-nm and the line stimuli had previously been reinforced. In Experiment 2, two (TD) groups of pigeons (n=16) were given single stimulus training with a 555-nm keylight followed by eight sessions of discrimination training with two line angles, then one session of non-differential (ND) training with the same two lines, and then a wavelength generalization test either immediately or after a 24-h delay. Two other (hold) groups (n=16) received similar training, except for the TD Une angle training sessions, in these hold groups, the wavelength gradient was flatter in a delayed test; in the TD groups it was steeper, indicating PI from the prior TD training. These two experiments suggest that the “attentional sets,” which purportedly result from TD and ND training, may fruitfully be viewed as target memories subject to the principles of interference theory. 相似文献
4.
In multiple fixed interval (FI) schedules, rats are trained to discriminate different FIs that are signaled by different stimuli. After extensive training, the different stimuli often acquire control over performance, observed by an earlier increase in responding for stimuli that signal shorter FIs, as compared with stimuli that signal longer FIs. The order in which the different FIs are trained, either intermixed across cycles or in blocks of several cycles, may seem irrelevant given that average performance at asymptote may be similar. In this study, rats were trained in two procedures with multiple FIs presented intermixed within sessions or in blocks of one interval per session. Similar performance was observed at asymptote, but an inspection of early cycles in each session revealed that different stimuli acquired control over performance only when trained intermixed within each session. Although the stimuli reliably signaled the upcoming FI, when trained in successive blocks of 60 cycles, rats rapidly adjusted performance early in the sessions on the basis of the temporal aspects of the task, and not on the basis of the stimulus presented in the current cycle. These results are discussed in terms of overshadowing of the stimuli by temporal cues and in terms of conditions under which a stimulus acquires control over performance. 相似文献
5.
Two pigeons matched to sample in a three-key operant conditioning chamber. In Experiment I, two different kinds of samples were presented on the center key.Element samples were members of one of two sample sets — colors (a red or blue disk) or lines (a vertical or horizontal orientation of a set of white lines). These samples were followed by their respective sample sets on the side keys as comparison stimuli.Compound samples consisted of a set of lines superimposed on a colored disk. Following these samples, either sample set could appear as comparison stimuli. Matching to compound samples was less accurate than matching to element samples. One interpretation is that sharing of attention among elements of a compound sample weakened stimulus control by each element. A different interpretation is that an element sample controlled matching better because it was physically identical to a comparison stimulus whereas a compound sample was not. Experiments II–IV evaluated this “generalization decrement” alternative by testing element- vs. compound sample control with both element and compound comparison stimuli. Irrelevant elements were added to form compound comparison stimuli, some of which were physically identical to a preceding compound sample, but never identical to an element sample. In all experiments, the addition of irrelevant elements of comparison stimuli reduced sample control. However, the generalization decrement hypothesis failed to predict how differences in performance maintained by element and compound samples were affected by different tests of sample control. Matching accuracy appeared to be independently determined by the number of elements in a sample and whether irrelevant elements were present during tests of sample control. 相似文献
6.
In order to assess the abilities of two California sea lions to generalize an identity concept, both animals were taught a two-choice, visual matching-to-sample task. We hypothesized that initial identity-matching problems would be learned as conditional (if...then) discriminations but that an identity concept would emerge after training numerous exemplars of identity matching. After training with 15 two-stimulus identity matching-to-sample problems, transfer tests consisting of 15 novel problems were given to the animals. Pass-fail criteria were defined in terms of performance on Trial 1 of each test problem, performance on test trials compared with baseline trials, and performance on four-trial problem blocks. One sea lion passed on the second transfer test and the other passed on the third; both demonstrated successful generalization of an identity concept by all criteria used. A second experiment consisted of presentation of stimuli previously learned in a different context (arbitrary matching-to-sample). Both subjects immediately applied an identity concept to accurately solve these new problems. These tests conclusively demonstrate transfer of an identity matching rule in California sea lions. 相似文献
7.
The present research tested the generality of the “work ethic“ effect described by Clement, Feltus, Kaiser, and Zentall (2000).
In Experiment 1, we trained 10 pigeons on a pair of either simultaneous or successive discriminations. One discrimination
followed a high-effort requirement (20 pecks to the center key) and the other followed a low-effort requirement (1 peck).
Contrary to Clement et al.’s results, we found that preferences between the S+ and S− stimuli in transfer tests depended on the event that initiated the trial: Pigeons preferred the stimulus from the baseline
discrimination whose initiating event was most dissimilar from that preceding the test trial. Preferences were similar but
less extreme in the successive condition. In Experiment 2, we investigated whether test preferences depended on the amount
of training. A total of 12 pigeons were trained on a pair of simultaneous discriminations, except that test sessions were
scheduled after every three baseline sessions. Preferences increased across test sessions but were similar to those in Experiment
1. Together with Vasconcelos, Urcuioli, and Lionello-DeNolf (2007a), our study represents a second failure to replicate Clement
et al.’s work ethic effect. The finding that preference depends on the event that initiates the test trial suggests that choice
probes may not provide unambiguous assessments of stimulus value. 相似文献
8.
Illumination effects during steady-state performance of discrimination tasks in animals have been well documented, whereas research on illumination effects during acquisition has been largely ignored. Exceptions to this rule are Wasserman’s (1973) autoshaping experiments and Maki’s (1979) successive discrimination experiment. The present experiment investigated the effects of illumination changes on acquisition of a conditional discrimination—delayed matching-to-sample (DMTS). Pigeons were used in a between-groups design which factorially varied house-light illumination, on or off, during the presentations of DMTS stimuli, the delay interval, and the intertrial interval (ITI). DMTS performance over five blocks of sessions was the dependent variable. The major result was the three-way interaction of sessions, the intertrial interval, and the DMTS stimuli. Constant illumination resulted in the highest discrimination ratios over the last four blocks of sessions. A constant dark condition did not differ from a condition with dark ITIs and illuminated stimulus presentations or from a condition with illuminated ITIs and dark stimulus presentations. The proffered explanation of these data emphasizes the disruptive effects of stimulus changes and Wasserman’s (1973) cue localization hypothesis. The loci of the stimulus change and cue localization effect are suggested to be either at the beginning of a trial or at the end of a trial. A pretrial account emphasizes the role of stimulus changes on the encoding of the sample stimulus, and a posttrial account emphasizes the role of stimulus changes during consolidation processing. 相似文献
9.
A bottlenose dolphin was trained to discriminate two simultaneously presented stimuli differing in numerosity (defined by
the number of constituent elements). After responding correctly to stimuli consisting of three-dimensional objects, the dolphin
transferred to two-dimensional stimuli. Initially, a variety of stimulus parameters covaried with the numerosity feature.
By systematically controlling for these stimulus parameters, it was demonstrated that some of these attributes, such as element
configuration and overall brightness, affected the animal’s discrimination performance. However, after all the confounding
parameters were under control, the dolphin was able to discriminate the stimuli exclusively on the basis of the numerosity
feature. The animal then achieved a successful transfer to novel numerosities, both intervening numerosities and numerosities
outside the former range. These findings provide substantial evidence that the dolphin could base his behavior on the numerosity
of a set independently of its other attributes and that he represented ordinal relations among numerosities. 相似文献
10.
Study time and test performance change as a function of subjects expecting either open questions or a multiple-choice test on the contents of a history text. After studying a first history text, the subjects immediately received a test consisting of either open questions or multiple-choice items. They were led to expect the same type of test on a second text. Study time on Text 2 was self-paced, and the type of test was either the expected or unexpected one (either open questions or a multiple-choice test). The main hypothesis was confirmed that subjects consider open questions a more demanding test than a multiple-choice test. Accordingly, subjects expecting open questions on Text 2 used more study time and performed better on both types of test than did subjects expecting a multiple-choice test. Internal analyses revealed that the differences on study time and test achievement between the two expectation conditions occurred only when the subjects were thoroughly acquainted with the processing requirements of the learning material and its expected test. 相似文献
11.
We tested a California sea lion for visual oddity learning by presenting problems composed of three two-dimensional black-and-white
stimuli, two identical (S−) and one different (S+). In the first experimental stage, a single problem per session was presented
until learning criterion was reached. In the second experimental stage, all problems were presented only five times in succession;
then a new problem was introduced (six problems/session). In the third experimental stage, each problem was presented only
once. The sea lion mastered all stages of oddity learning. A final transfer test with oddity problems composed of completely
new stimuli yielded performance significantly above chance. Data analyses suggested learning of specific stimulus properties
in the first stage, learning set formation in the second stage, but oddity conceptualization in the third stage. 相似文献
12.
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
13.
The present work introduced a task which superimposed a tray brightness, stimulus-response contingency on previously acquired, highly successful, one-trial oddity performance. Continuing with new one-trial oddity problems, the new contingency was that responses to the odd objects were rewarded on a white tray and responses to the nonodd objects were rewarded on the black tray. Since there is no opportunity to learn specific stimuli or stimulus patterns, successful performance may be interpreted as having a conceptual basis. All monkeys achieved criterion (90% based on 18/20) and statistically significant performances (p<.001). Discussion considered the appropriate nomenclature to describe a conceptual conditional discrimination task and the necessary evidence to justify a conceptual interpretation of conditional discrimination behavior. 相似文献
14.
Bruno Poucet Nicole Chapuis Madeleine Durup Catherine Thinus-Blanc 《Learning & behavior》1986,14(1):93-100
This experiment investigated the role of exploration in the formation of maps of the environment. The effects of spatial rearrangement of four familiar objects in an open field on subsequent exploratory behavior were studied in hamsters (Mesocricetus auratus). During two exploratory sessions, four groups of subjects were exposed to objects in a particular spatial relation to each other and to a distal pattern. During a testing session, the control group was exposed to the same situation as during the first two sessions, and the three experimental groups were exposed to various object rearrangements. The hamsters in the experimental groups, but not those in the control group, renewed their exploration of the objects during the testing session, as measured by the number of contacts with the objects and the time spent investigating them. Further analyses of the nature of the reinvestigated objects (i.e., displaced or nondisplaced) support the hypothesis that, through exploration, a long-lasting representation of the environment is built up on the basis of the topological relations among the objects, the overall geometric structure provided by the arrangement of the objects, and the relations between the objects and extra-apparatus landmarks. 相似文献
15.
74 lower- and middle-class children aged 2 1/2, 3 1/2, and 4 1/2 years who were successful at unidimensional sorting of 2 objects by either color or form were given feedback for correct bidimensional sorting of 3 objects, 2 of which had been used in unidimensional testing. Four of the 10 2 1/2-year-olds and 58 of the 64 3 1/2- and 4 1/2-year-olds reached criterion on the bidimensional sorting task. Neither social class nor performance on a verbal comprehension test (the Peabody Picture Vocabulary Test) was significantly correlated with success on either unidimensional or bidimensional sorting, although social class and test scores were significantly correlated. The results indicate that Piagetian centration (i.e., the inability to transcend unidimensional attention) is a task- or situation-specific phenomenon, and biodimensional responding is the rule rather than the exception for 3 1/2- and 4 1/2-year-olds in an instrumental situation involving a limited number of stimuli. 相似文献
16.
In evaluating the relationship between two measures across different groups (i.e., in evaluating “differential validity”) it is necessary to examine differences in correlation coefficients and in regression lines. Ordinary least squares (OLS) regression is the standard method for fitting lines to data, but its criterion for optimal fit (minimizing the squared vertical distances between the points and the line) is less natural in many contexts than the criterion used in orthogonal regression (minimizing the squared Euclidean distances of points from the line). OLS regression is appropriate if the goal is to predict some unknown dependent variable from a known independent variable, but in examining the relationship between two variables, which both contain error, OLS regression introduces bias. This bias, associated with regression toward the mean, can suggest that the test scores have different relationships, and therefore different meanings, in two groups, when the two sets of test scores have the same relationship and the same meanings in the two groups. The impact of regression toward the mean in differential validity studies is illustrated with two synthetic and two real data sets. Each of the two real data sets include two measures of competence in applying legal principles to fact situations (an essay test and a multiple-choice test) for candidates in two groups (Black/White in the first example and women/men in the second example). 相似文献
17.
Pigeons were trained to learn an instrumental oddity-from-sample discrimination involving visual forms. One group, the “few examples” group, dealt with 5 patterns in 40 different combinations. Another group, the “many examples” group, dealt with 20 patterns in 160 different combinations. After both groups had reached asymptotic performance and had learned to operate under partial reinforcement conditions, they were tested for transfer under extinction conditions with two different groups of 5 novel patterns, each in 40 combinations. All animals showed significant above chance transfer to both of these novel stimulus sets. Transfer performance with test stimuli of similar geometric design to training stimuli was better than performance with stimuli of markedly different design. The transfer performance of the “many examples” group was marginally better than that of the “few examples” group, even though the latter’s performance on the training stimuli was better throughout. It is concluded that pigeons can learn to employ an oddity concept and that this may be promoted by the use of many training exemplars. Furthermore, it is inferred that pigeons may normally use a mixture of strategies to solve oddity and identity problems. 相似文献
18.
David S. Tuber 《Learning & behavior》1986,14(4):421-426
Based upon considerations raised by Soviet research, the role of relative stimulus intensity, or dominance, in the unconditioned stimulus-unconditioned stimulus (US-US) paradigm was investigated under circumstances presumed favorable to the backward conditioned response (CR). Using the classically conditioned forelimb response of the cat, a brief shock (USD delivered to one forepaw preceded a shock (US2) to the opposite forepaw in paired conditioning fashion; subjects in the control group received explicitly unpaired presentations of the stimuli. Conditioning in both the forward and backward directions was evaluated by the appearance of contralateral CRs on test trials to each of the USs. In Experiment 1, a ratio of the intensities between US1 and US2 of 100:80 was used to create a relative dominance in favor of the backward CR. In addition, to evaluate the suggestion that the appearance of the backward CR is retarded in the Pavlovian paradigm, overtraining was provided to a forward conditioning criterion of 200%. In Experiment 2, the cats were exposed to successive reductions in the intensity of US2 to verify manipulations of dominance reportedly involved in the reactivation of a latent backward CR. Although forward conditioning was readily established to USl, there was no evidence of back-ward conditioning to US2 under any of the conditions. 相似文献
19.
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
20.
Within-session changes in responding during delayed matching-to-sample and discrimination procedures
Two experiments examined within-session changes in responding during discrimination procedures. In Experiment 1, rate of responding changed significantly within sessions during symbolic delayed matching-to-sample tasks when the delay between the stimulus and the choice period was short (1–5 sec), but not when it was long (8–12 sec). The percentage of responses that were correct did not change within sessions. In Experiment 2, response rates increased and then decreased within sessions during both S1 and S2 when successive discrimination procedures provided high, but not low, rates of reinforcement. Discrimination ratios sometimes increased within sessions. These results question two potential definitions of attention as explanations for within-session changes in response rates. They are more compatible with explanations based on concepts such as arousal, satiation, habituation, and interfering responses. 相似文献