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1.
H. L. Roitblat 《Learning & behavior》1980,8(3):341-351
The delayed matching-to-sample (DMTS) task was used in three experiments to investigate how pigeons code information about sample stimuli. In all experiments, each trial consisted of a signaled presentation of a sample stimulus for a fixed duration followed, after some delay, by the presentation of three comparison stimuli. After incorrect first choices, the bird was allowed a second choice between the remaining two stimuli. It was found, in Experiment 1, that the probability of a second choice error declined with increasing sample duration. This result is consistent with a gradual short-term memory encoding process but not with a simple two-state all-or-none process. In the second experiment, it was found that the distribution of first-choice errors was affected by the particular sample occurring on a trial. This result is inconsistent with a two-stage discrete state memory/attention model based on the assumption that encoding of the sample and attention to the comparison stimuli are both independent all-or-none processes. The third experiment involved symbolic DMTS, in which the sample stimuli varied along a dimension different from that along which the comparison stimuli varied. With increasing delay between sample and comparison stimulus presentations, the pigeons were more likely to confuse test stimuli than to confuse sample stimuli. The results of these experiments lead to the conclusion that pigeon DMTS performance depends on a gradual encoding process in which a representation isomorphic with the test stimuli is generated and maintained. 相似文献
2.
The usual procedure in delayed-matching-to-sample (DMTS) experiments is that the most recently presented sample stimulus is correct on choice tests. The present paper reports two experments in which the first of two samples was always correct. Theories based on trace strength, such as the Roberts and Grant trace strength competition model, predict that such a procedure will yield below chance performance, because on the average the more recently presented stimulus will have the greater trace strength. In contrast, D’Amato and others have proposed that DMTS performance is mediated by a temporal discrimination process and, since either stimulus may act as S+ in a discrimination problem, monkeys should be capable of learning to choose either the secondor the first of two sample stimuli. Performance did not exceed chance in either experiment. The generality of these results is tentatively explored. 相似文献
3.
Separate groups of rats were trained and tested on asymmetrically and symmetrically reinforced successive delayed matching-to-sample (DMTS) or delayed discrimination (DD) tasks in Experiment 1. Each rat received training and testing on symmetrically reinforced DMTS and DD tasks in Experiment 2. The only difference between each task was that the rats had to respond correctly to a light or tone test stimulus, S2, if it matched a light or tone sample stimulus, S1, in DMTS, but could respond to either S2 if S1 had been a particular stimulus in DD. Only correct leverpresses were reinforced in the asymmetrically reinforced version of each task. Both correct presses and correct omissions were reinforced in the symmetrically reinforced version of each task. Response biases to leverpress during tests for delayed responding to S1 were reduced in both symmetrically reinforced tasks, but only in the DD task did such contingencies produce consistently poorer performance in responding to either S, in Experiment 1. Declines in accuracy of performance that occurred in both experiments were greater to the visual than to the auditory S1 only in the DMTS tasks with increased intervals between S1 and S2. A third experiment, in which rats had to respond to S2 if it matched S1 (DMTS) or if S2 mismatched S, (DMmTS), was carried out. Modality of S1 similarly affected accuracy of delayed responding in each task, as in the first two experiments. Methodological and theoretical implications of these results are discussed in terms of Honig and Thompson’s (1982) dual-process theory of working memory. 相似文献
4.
Previous research in directed forgetting in pigeons has focused on the effect of single forget cues (F-cues) interpolated within the retention interval in delayed matching-to-sample (DMTS). The present series of experiments focuses on the ability of a remember cue (R-cue) to cancel the effects of a previously presented forget cue both when the forget cue occurs within the retention interval and when the forget cue precedes sample presentation. In the first experiment, an R-cue decreased the effect of an F-cue within the same retention interval in successive DMTS if the R-cue immediately followed the F-cue, but not if the second cue was delayed until the end of the retention interval. In Experiment 2, the double-cue effect was extended to choice DMTS. In addition, when a novel stimulus replaced the R-cue in the double-cue probe trials, matching performance was not restored, indicating that through its conditioning history the R-cue had gained control over memory processes in a direction opposite to that of the F-cue. Experiment 3 presents evidence that presample R- and F-cues can also effectively gain control over matching performance. Matching to R-cued samples was superior to matching to F-cued samples. When F-cued samples were followed immediately by R-cues, matching performance was not restored to R-cue levels, suggesting differential encoding of the R-cued and F-cued samples. 相似文献
5.
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
6.
Two experiments investigating odor production and utilization in rats under the effects of Thorazine and Elavil injections, respectively, are reported. In Experiment 1, significantly slower speeds shown by the Thorazine-injected subjects indicated that this drug depressed performance. It is felt that depressed performance allowed these subjects to attend and respond to odor cues earlier in Phase 1 than did saline-injected control animals. Reversing the injection conditions (Phase 2) failed to disrupt already-established patterning. During the first phase of Experiment 2, Elavil-injected subjects failed to establish patterned responding, whereas such responding was readily established by saline-injected subjects. Reversing the injection conditions (Phase 2) resulted in the rapid development of double-alternation patterning by the subjects that were shifted from Elavil to saline and in the maintenance of such responding by the animals shifted from saline to Elavil. 相似文献
7.
Dorothy Munkenbeck Fragaszy 《Learning & behavior》1981,9(1):127-134
Squirrel monkeys (Saimiri sciureus) and titi monkeys (Callicebus moloch) were tested in three two-choice visual discrimination experiments. Although, on average, squirrel monkeys performed more accurately than titis, the range of response accuracies in the two species overlapped considerably in all three experiments and changes in response accuracy over test sessions and across experiments were similar in the two species. Thus, the species shared several behavioral characteristics expected of New World primates in this setting. Squirrel monkeys’ performance appeared to be more affected than titis’ by task difficulty, and squirrel monkeys were individually less consistent than titis. These differences were associated with higher activity levels and briefer overt attentiveness to the repetitive task in squirrel monkeys and, conversely, with lower activity levels, slower working speeds, and sustained interest in the task in titis. The associated differences are discussed in relation to each species performance in other laboratory settings and the characteristic patterns of foraging and use of space in nature. 相似文献
8.
Ronald F. Mervis 《Learning & behavior》1974,2(3):238-240
TwoLemur catta were tested in a WGTA on three two-choice color discrimination problems involving paired comparisons of red, green, and blue. Four illumination combinations between the two discriminanda served to make brightness irrelevant, hue being the only salient cue. All color problems were learned within criterion limits of 21 out of 25 correct choices during 16 consecutive test sessions, indicating good color vision for this diurnal prosimian. 相似文献
9.
10.
Shayna Rusticus Anne Worthington Derek Wilson Karen Joughin 《Learning Environments Research》2014,17(3):423-435
The Medical School Learning Environment Survey (MSLES) was used with a sample of 311 undergraduate medical students in British Columbia, Canada, to assess the seven scales of Medical Breadth of Interest, Personal Breadth of Interest, Emotional Climate, Flexibility, Meaningful Learning Experience, Organization, Nurturance and Student–Student Interaction. Confirmatory factor analysis was used to support the validity of the MSLES when used with this sample. 相似文献
11.
Sucrose aversions were induced by lithium chloride toxicosis in 9-week-old male and female mice of the C57BL/6J and DBA/2J strains. Under conditions of ad-lib access to fluids which required a long interval between the sucrose and toxicosis, the conditioned aversions were relatively weak when compared with the sucrose consumption of saline-injected controls. The aversions extinguished rapidly within all groups. Contrary to earlier reports in rats, no sexual dimorphism in extinction rate was observed in this paradigm. When a fluid-deprivation schedule was implemented in the conditioning procedure to shorten the interval between taste experience and toxicosis, strong aversions were noted; yet relatively fast extinction under ad-lib conditions occurred in all groups except male DBA/2J mice. No sexual dimorphism was observed in mice of the C57BL/6J genotype, even when two pairings between sucrose and toxicosis were administered. 相似文献
12.
Three groups of college students were given instructions using different testing techniques to determine whether the superior performance obtained with Programmed Student Achievement (PA) was due to a Hawthorne Effect. PA students, operating under the consequence of failing the course if they failed to evidence criterion performance (100% mastery) on weekly quizzes, exhibited superior performance, relative to control groups, on the weekly quizzes and on an unannounced retention test. The results seem to preclude any attempt to interpret the effectiveness of Programmed Student Achievement on the basis of a Hawthorne Effect. 相似文献
13.
Arthur L. Savage 《Educational technology research and development : ETR & D》1975,23(4):415-426
Thomas Aquinas, who knew more about education and persuasion than almost anybody who ever lived, once said that when you want to convert someone to your point of view, you go over to where he is standing, take him by the hand (mentally speaking), and guide him to where you want him to go. You don’t stand across the room and shout at him. You don’t call him a dummy. You don’t order him to come over to where you are. You start where he is, and work from that position. That’s the only way to get him to change. Sidney Harris (1973) 相似文献
14.
Schmallenberg virus causes stillbirths in animal populations like cattle, goats, sheep, bison and Alpaca. The first case was reported in Germany in November 2011 in a town called Schmallenberg. Consequently, many more cases were reported all over Europe, in The Netherlands, Belgium, the United Kingdom and France. Here, we elaborate on the recently identified Schmallenberg virus and its pathological outbreak in animals. 相似文献
15.
Brian A. Woodcock 《Science & Education》2014,23(10):2069-2093
“The Scientific Method” as it has been portrayed in popular and introductory contexts has been declared a myth. The variation that one finds in introductory presentations of “The Scientific Method” is explained by the fact that there is no canonical account among historians and philosophers of science. What, in particular, is wrong with “The Scientific Method”? This essay provides a fairly comprehensive survey of shortcomings of “The Scientific Method”. Included are corrections to several misconceptions that often accompany such presentations. Rather than treating “The Scientific Method” as a useful approximation or an ideal, the myth should be discarded. Lessons can be learned for introductory pedagogical contexts from considering the shortcomings of the myth. 相似文献
16.
Allan M. Schrier 《Learning & behavior》1985,13(4):392-396
Stumptailed monkeys (Macaca arctoides) were given two two-choice line-discrimination problems in which the lines were presented either alone or embedded in a patterned context that was the same in all cases. When the stimuli were a left- and a right-tilting line, the addition of the context significantly improved performance, as measured by frequency of correct choice responses. It also decreased choice response latency, duration of visual fixations, and frequency of scanning back and forth between the two stimuli. When the stimuli were a horizontal and a vertical line, the addition of the context had the opposite effect on all the performance measures. These results are very similar to those found with adult and infant humans when given the same stimuli. They suggest that the pattern perception of monkeys, like that of humans, involves top-down or holistic processing of incoming visual information. 相似文献
17.
Richard J. Wallace 《Learning & behavior》1979,7(4):549-554
Experiments on object preferences indicate that there are at least two characteristics that induce albino rats to hoard inedible objects: partible objects are hoarded in preference to nonpartible objects, and novelty results in hoarding when other object-characteristics are controlled. In addition, novel objects may be hoarded by food-deprived rats in preference to food pellets. Hoarding can therefore be integrated into a number of other motivational systems. It is suggested that an incentive concept is necessary to explain hoarding preferences in this species. 相似文献
18.
Four experiments with rats tested their ability to anticipate serial patterns made from elements of reward magnitudes (14, 7, 3, 1, or 0 food pellets). Anticipation was measured by the running time in a straight alley. Elements arranged in a monotonically descending pattern were more easily anticipated than were the same elements arranged in a nonmonotonic pattern. Better anticipation was also observed when training utilized four trials per day with short interrun intervals (10–15 sec), spent in the startbox of the runway, than when training utilized one trial per day with long interrun intervals (4–5 min), spent in the rat’s home cage. Anticipation of the monotonie sequence was also superior when training consisted of one trial per day with a short interrun interval relative to that observed with four trials per day and a long interrun interval. Following acquisition of anticipation of the monotonie sequence with a short interrun interval, transfer to the same sequence with a long interrun interval resulted in disruption of anticipation. Finally, anticipation of a well-learned monotonie sequence was not disrupted by replacement of individual rewarded elements in the sequence with a 0-pellet element. These experiments indicate that the duration between runs of a trial, but not that between trials or the number of trials per day, is important in the formation of serial expectancies. They also suggest that the rats come to represent the sequence as items in serial position. 相似文献
19.
Stephen Ntim 《Higher Education》2014,68(6):837-849
High quality provision has been one of the key aims of the current reforms in higher educational institutions across the globe since the beginning of the century and the millennium. Consequently this has led to the increasing demand for quality assurance (QA). This report identifies those institutional processes and structures that support the development of an internal quality culture in the emerging private universities in Ghana. The study bases its understanding of “quality culture” on the definition which sees it as referring to an organizational culture characterized by a cultural/psychological element on the one hand, and a structural/managerial element on the other hand. If we take our educational activity as a process, then the process (the activity) requires inputs (information, materials), resources (people, equipment, space) and control (QMS) to produce outputs (products and/or services). QA then is a culture—a way of continuously aiming to improve and do better—and the private universities in Ghana are responding to this. 相似文献
20.
Bobbie A. Henderson 《Early Childhood Education Journal》1983,11(1):10-11
CIA does not stand for what you ordinarily would think, The Central Intelligence Agency! These initials can be quite meaningful to caregivers and definitely beneficial to school-agers who are involved in before and after school care. CIA—Creativity, Imagination and Anticipation! These are key words and functions which can enhance a school-age program. 相似文献