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1.
Pigeons discriminated between two pairs of durations: a short set (2.5 and 5 sec) and a long set (5 and 10 sec). The pairs
were intermixed within sessions and identified by the colors on the signal and choice keys. Once the task was learned, the
pigeons experienced the following three conditions seriatim: (1) The signal key was made ambiguous about the test change,
but the choice keys were informative (retrospective); (2) the signal key identified the test range, but the choice keys did
not (prospective); (3) probe trials were introduced in which the color of the center key signaled one test range, but the
color of the choice keys signaled the other test range (inconsistent). Accuracy of choice decreased in the retrospective condition
and, returned to baseline levels, was higher under the prospective condition than under the retrospective condition. In a
final condition, referred to as conflict trials, the center-key color signified one test range and the choice-key colors the other range. The results from these conflict-inconsistent
tests indicate that choice behavior was largely controlled by the signal-key color and not by the choice-key color. We relate
these findings to different approaches to timing in animals. 相似文献
2.
Ruma Falk Patricia Yudilevich-Assouline Adily Elstein 《Educational Studies in Mathematics》2012,81(2):207-233
Children had to choose one of two urns—each comprising beads of winning and losing colours—from which to draw a winning bead. Three experiments, aimed at diagnosing rules of choice and designed without confounding possible rules with each other, were conducted. The level of arithmetic difficulty of the trials was controlled so as not to distort the effects of the constituent variables of proportion. Children aged 4 to 11 first chose by more winning elements and proceeded with age to choices by greater proportion of winning elements. There were some indications of intermediate choices by fewer losing elements and by greater difference between the two colours. Distinguishing correct choices from favourable draws, namely acknowledging the role of chance in producing the outcome and insisting on the right choice, grew with age. Children switched rather early from considering one dimension to two; they combined the quantities of winning and losing elements either additively by difference or, with age, mostly multiplicatively by proportion. Guided playful activities for young children, based on this research, are suggested for fostering acquisition of the basic constituents of the probability concept: uncertainty of outcome, quantification by proportion, and the reverse relation between the chances of complementary events. 相似文献
3.
Philipp J. Kraemer 《Learning & behavior》1991,19(3):276-282
Two experiments examined the performance of pigeons on symbolic-matching-to sample in which the relevant sample dimension consisted of duration. Each pigeon was trained on two problems that had the same two sample durations, 2 and 10 sec, but were different with respect to other physical properties of the samples. Durations of light and tone were used in Experiment 1; durations of two different color-location compounds were used in Experiment 2. In each experiment, a unique choice stimulus was associated with each of the four possible combinations of duration and signal type. Test sessions contained probe trials in which the choice stimuli were these appropriate for a long and a short duration of the signal type opposite to that actually presented. Pigeons in both experiments displayed asymmetrical performance deficits. Accuracy on long durations dropped to chance or below, whereas accuracy on short durations remained high. This pattern is similar to the choose-short effect that is obtained when animals are tested with long retention intervals. The implications of these results for duration memory, coding, and transfer of training are discussed. 相似文献
4.
Donald M. Wilkie 《Learning & behavior》1988,16(2):132-136
We have found proactive effects in pigeons’ timing behavior, a finding inconsistent with internal-clock models of timing that assume a resetable working-memory component. Six pigeons were trained to discriminate between 2- and 10-sec illuminations of a white light; choice of a red pecking key was correct and rewarded after presentation of the short stimulus whereas choice of a green key was correct and rewarded after presentation of the long stimulus. During training sessions, there were 60 trials separated by a 20-sec intertriai interval; short and long light occurred in a randomized order and correct choices were reinforced with 5-sec access to grain on a partial (75%) schedule. During test sessions, there were 120 trials separated by a 2-sec intertrial inter val. Light presentations occurred in a fixed order throughout these sessions: 2, 6, 10, 10, 6, 2 2, 6, 10 sec, and so forth. Choice of either red or green after 6 sec was not reinforced. However, red continued to be correct after 2 sec and green continued to be correct after 10 sec. Of central interest was how the subjects classified 6 sec of light in ascending (2, 6, 10) and descending (10. 6, 2) sequences of durations: Subjects chose the short alternative on 42% of the 6-sec trials in ascending series but only 29% in descending series, a result most plausibly interpreted as show ing that duration information from a preceding trial affects duration classifications on the cur rent trial. Such proactive effects should not occur according to working-memory models that as sume that stored information is cleared at the end of a trial. 相似文献
5.
In three experiments, pigeons were trained to discriminate between uniform arrays of two elements that differed in color, form, or size. They were then tested with arrays that contained different proportions of the two elements on these dimensions. In all cases, orderly discrimination gradients reflected these proportions. The discrimination readily transferred to new arrays with similar stimuli, but with different total numbers of elements. In Experiment 4, the pigeons were taught to discriminate between two groups of categorical stimuli: pictures of birds and pictures of flowers. A test with different proportions of each again produced a gradient based on relative numerosity. Experiment 5 demonstrated transfer of stimulus control on the numerosity dimension when pigeons were trained with one set of instances from two categories, and then were tested with new instances from the same categories. 相似文献
6.
We report the first successful demonstration of a simultaneous, two-itemsame-different (S/D) discrimination by 6 pigeons, in which nonpictorial color and shape stimuli were used. This study was conducted because
the majority of recently successful demonstrations of S/D discrimination in pigeons have employed displays with more than
two items. Two pairs of stimulus items were simultaneously presented on a touch screen equipped computer monitor. Pigeons
were reinforced for consistently pecking at either thesame (i.e., identical) or thedifferent (i.e., nonidentical) pair of items. These pairs were created from combinations of simple colored shapes drawn from a pool
of six colors and six shapes. After acquiring the discrimination with item pairs that differed redundantly in both the shape
and the color dimensions, the pigeons were tested for transfer to items that varied in only one of these dimensions. Although
both dimensions contributed to the discrimination, greater control was exhibited by the color dimension. Most important, the
discrimination transferred in tests with novel colored, shaped, and sized items, suggesting that the mechanisms involved were
not stimulus specific but were more generalized in nature. These results suggest that the capacity to judge S/D relations
is present in pigeons even when only two stimuli are used to implement this contrast. 相似文献
7.
The effects of identical context on pattern recognition by pigeons for outline drawings of faces were investigated by training
pigeons to identify (Experiment 1) and categorize (Experiment 2) these stimuli according to the orientation of the mouth—an
upright U shape representing a smiling mouth or an inverted U shape representing a sad mouth. These target stimuli were presented
alone (Pair 1), with three dots in a triangular orientation to represent a nose and eyes (Pair 2), and with the face pattern
surrounded by an oval (Pair 3). In Experiment 1, the pigeons trained with Pair 1 were most accurate, those trained with Pair
2 were less so, and those trained with Pair 3 failed to acquire the discrimination within eighty 100-trial sessions. The same
ordering was found in Experiment 2 for pigeons trained on the three pairs simultaneously. The authors suggest that a contrasting
finding in humans, the face superiority effect, might be due to a gain in discriminability resulting from recognition of the
pattern as a face. An exemplar model of information processing that excludes linguistic coding accounts for the present results. 相似文献
8.
The influence of dimensional organization on pigeon texture perception was examined in a simultaneous conditional discrimination procedure. Six experienced pigeons were reinforced for pecking at a small block oftarget elements randomly located within a larger array ofdistractor elements in each texture stimulus. Target/distractor differences in color, size, orientation, and combinations of these dimensions were examined. In Experiment 1, the influence of target/distractor similarity on performance was investigated by using different forms of unidimensional and conjunctively organized texture stimuli made of two and three dimensions. Targets infeature displays, in which the two regions consistently differed along a single dimension, were located more accurately than targets inconjunctive displays, where a combination of values from all dimensions defined each region. In Experiment 2, a tradeoff between response speed and accuracy was found in the pigeons’ processing of conjunctive displays. In Experiment 3, the number of distractors differentially influenced the localization of feature and conjunctive targets. Overall, the pigeons’ reactions to these feature and conjunctive stimuli paralleled those of humans, suggesting that functionally equivalent mechanisms may mediate the perceptual grouping, search, and discrimination of textured multidimensional stimuli in both species. 相似文献
9.
Pigeons were trained on two independent tasks. One involved red and yellow hues, the other involved blue and green hues. For half of the birds, the two tasks were the same (i.e., both tasks were either matching-to-sample, or oddity-from-sample). For the remaining birds, the two tasks were different (i.e., one task was matching-to-sample; the other task was oddity-from-sample). Following acquisition, the pigeons were exposed to test trials on which either the correct or the incorrect comparison hue was replaced with one of the hues from the other task. On yellow-sample trials and on green-sample trials, the pigeons performed as if they had a common code for yellow and green. When there was one comparison available that was appropriate to the “yellow/green” code, performance remained high; but when either both comparisons or neither comparison was appropriate to the “yellow/green” code, performance dropped. The pigeons also tended to code red samples as green and to code blue samples as yellow. The results indicate that pigeons can categorically code colors under conditions that rule out a failure to discriminate among the colors. 相似文献
10.
There is evidence that humans' perception of time is affected by the activity in which they are engaged while they are timing. The more demanding the task, the faster time appears to pass. A similar effect has been found in pigeons. Pigeons trained to discriminate between a short-duration (2-sec) and a long-duration (10-sec) stimulus were required to peck when the stimulus was one color and to refrain from pecking when it was a different color. On probe trials of intermediate durations, the bisection point (50% choice of the stimulus associated with both long and short stimuli) for trials in which the pigeons were required to peck was almost 1 sec longer than on trials in which the pigeons were required to refrain from pecking (Zentall, Friedrich, & Clement, 2006). In the present research, we replicated this effect and determined the relation between this effect and the typical bisection point that occurs when pecking is permitted but not required. Results indicated that the typical procedure results in a bisection point that is between required pecking and refraining from pecking. Furthermore, the rate of pecking when pecking is allowed but not required also falls between the rate of pecking for the required-pecking and refrain-from-pecking conditions. This result suggests that, similar to humans, pigeons underestimate the passage of time when they are active or when attention to time-related cues has to be shared with attention to satisfying the response requirement. 相似文献
11.
In this study, we embark on an exploration and analysis of a community of learners of science in a classroom of one of the
authors (Barbara Luster)—a group of Year 8 African American girls and boys in an urban, inner-city school. This study is a
collaborative action research project that examines closely the practice of teaching and learning science within a socio-cultural
perspective that Barbara has espoused and brought to her classroom. We study the two dimensions of a community of learners—social-organisational,
and intellectual-thematic—and how each evolved and influenced the other. As we explore these dimensions we pay particular
attention to the gender of the students, looking for similarities and differences between boys and girls in the patterns that
emerge. Our findings indicate that in Barbara's class the relative success of the learning community in terms of the social-organisational
dimension was not accompanied by a relative success in the intellectual-thematic dimension. Barbara and her students, for
the most part, succeeded in developing a community of people coming together to ask questions, offer their thinking, and respectfully
sometimes build on each other's contributions and sometimes disagree with each other. However, Barbara and her students did
not quite succeed in developing shared understandings, and we discuss the reasons for this. 相似文献
12.
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
13.
Angelo Santi 《Learning & behavior》1979,7(2):229-232
The effects of sodium pentobarbital on matching and oddity performance in pigeons were examined by employing a higher-order conditional discrimination paradigm. In this paradigm, the line orientation which was superimposed on all of the response keys signaled whether a response to the matching color or a response to the nonmatching color was correct. All pigeons had extensive previous training in this paradigm and were tested at each of three dosage levels: 5, 7.5, and 10 mg/kg. For all birds, a clear dose-related decrease in accuracy was observed; however, the effect was not differential for matching and oddity trials. Accuracy reductions were accompanied by an increase in position preference on both types of trials. The data are compatible with recent claims that physical identity of the sample and correct comparison stimulus need have no special status for pigeons. 相似文献
14.
Each of four pigeons was exposed to a single random-ratio schedule of reinforcement in which the probability of reinforcement
for a peck on either of two keys was 1/25. Reinforcer amounts were determined by an iterated prisoner’s dilemma (IPD) matrix
in which the “other player” (a computer) playedtit-for-tat. One key served as thecooperation(C) key; the other served as thedefection(D) key. If a peck was scheduled to be reinforced and the D-key was pecked, the immediate reinforcer of that peck was always
higher than it would have been had the C-key been pecked. However, if the C-key was pecked and thefollowing peck was scheduled to be reinforced, reinforcement amount for pecks on either key were higher than they would have been if
the previous peck had been on the D-key. Although immediate reinforcement was always higher for D-pecks, the overall reinforcement
rate increased linearly with the proportion of C-pecks. C-pecks thus constituted a form of self-control. All the pigeons initially
defected with this procedure. However, when feedback signals were introduced that indicated which key had last been pecked,cooperation (relative rate of C-pecks)—hence, self-control—increased for all the pigeons. 相似文献
15.
A comparison of the effects of scopolamine hydrobromide on working memory and reference memory in White Carneaux pigeons was undertaken by means of a modified delayed matching-to-sample procedure. Performance on working-memory trials was disrupted by decreases in sample duration and intertriai interval and by increases in delay interval. Performance on reference memory trials was not disrupted by any of these parametric manipulations. In Experiment 1, the pigeons received injections of scopolamine hydrobromide (0.01, 0.05, or 0.1 mg/kg), scopolamine methyl bromide (0.1 mg/kg), or saline prior to test sessions. In Experiment 2, the pigeons received injections of scopolamine hydrobromide (0.01 or 0.03 mg/kg), scopolamine methyl bromide (0.03 mg/kg), or saline. In both experiments, scopolamine hydrobromide had greater disruptive effects on working-memory trials than on reference-memory trials. The centrally active form of scopolamine disrupted working-memory trial accuracy more than the peripherally active form. However, no drug dose × delay interval interaction was obtained. Thus, the interference on working-memory-trial accuracy produced by central cholinergic blockade would not appear to be due to alterations in the active maintenance of information during the delay interval. 相似文献
16.
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
17.
Two experiments employed a delayed conditional discrimination procedure in which half the trials began with the presentation of food and half with no food; following a retention interval, subjects were presented with a choice between red and green keys, a response to one of which was reinforced according to whether the trial had started with food or no food. In Experiment 1, after 38 training sessions during which the retention interval was gradually increased, pigeons performed at a moderate level with intervals of 5 to 7.5 sec. A final test produced a steep forgetting function for food trials, but not for no-food trials; performance was unaffected by the duration of the intertriai interval (10 or 40 sec). Experiment 2 used the delayed conditional discrimination procedure to compare short-term memory in jackdaws (Corvus monedulus) with that in pigeons. Although the performance of the jackdaws was below that of the pigeons at the start of training, they showed more rapid learning over long delays, and, in the final test, a shallower forgetting function for food trials than that shown by pigeons. The results suggested superior short-term memory in jackdaws, which may help to explain the better performance of corvids in general when compared with that of pigeons in certain complex learning tasks. 相似文献
18.
In matching-to-sample, comparison choice should be controlled by the identity of the sample and, when the sample is not available,
by the overall probability of reinforcement associated with each of the comparisons. In the present research, pigeons were
trained to match a frequent sample (appearing on 80% of the trials) to one comparison (C
fr) and an infrequent sample (appearing on 20% of the trials) to the other (C
inf), with the number of reinforcements associated with each sample equated. In Experiment 1, the task was identity matching;
in Experiments 2 and 3, it was symbolic matching. We asked whether, when control of comparison choice by the sample was reduced
(by inserting a delay between the sample and the comparisons), pigeons would choose comparisons on the basis of (1) the number
of reinforcements per comparison (and thus show no comparison bias), (2) the comparison associated with the more frequent
sample during training (and show a preference forC
fr), or (3) the probability of reinforcement given a correct response (and show a preference forC
inf), or (4) inhibition produced by nonreinforced choice of the more frequently correct comparison (and show a preference forC
inf). Pigeons showed a significant tendency to chooseC
fr. In Experiment 3, we showed that this bias did not result from the effects of intertrial facilitation or interference. Thus,
it appears that when control of comparison choice by the sample is reduced, pigeons’ choice is controlled not merely by the
probability of reinforcement but also by overall sample frequency. 相似文献
19.
Isaac Behar 《Learning & behavior》1974,2(1):49-53
Relative performance on color and form dimensions during acquisition of two-cue problems by learning-set-sophisticated rhesus monkeys was evaluated with differential reinforcement. Six animals received 24 two-choice problems, each generated from three planometric stimuli, a reference stimulus, an alternate stimulus identical in color but differing in form, and one identical in form but differing in color. The reference stimulus appeared on every trial of a problem and was paired with one or the other alternate on a given trial On half of the problems, the reference stimulus was positive and on the remainder was negative. Acquisition was nearly equivalent on both cue dimensions with positive reference stimuli, but only one dimension was learned with negative reference stimuli. Results were interpreted as unfavorable to attention theory. 相似文献
20.
Donald M. Wilkie 《Learning & behavior》1987,15(1):35-39
Five pigeons were trained to discriminate between 2- and 10-sec illuminations of a white light; choice of a red pecking key was correct and rewarded after presentation of the short stimulus, whereas choice of a green key was correct and rewarded after presentation of the long stimulus. On half the trials, the light was bright; on the others, it was dim. Durations of 4, 6, and 8 sec of both dim and bright light were also presented; choices on these trials were not rewarded. The probability of the pigeons’ choosing the short alternative decreased in a graded manner as duration of both bright and dim light increased from 2, to 4, to 6, to 8, and to 10 sec. However, the pigeons were more likely to choose the short alternative with longer durations of the dim light than the bright light, a result that implies that the perceived duration of a dim light was shorter than that of a bright light of equal length. One interpretation of this effect is that stimulus intensity affects the rate of the pacemaker in an internal clock mechanism subserving timing of event duration. 相似文献