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Pigeons trained monocularly and tested with the trained eye along the angularity dimension were found to show enhanced area shifts when compared to pigeons trained and tested binocularly. Pigeons trained monocularly and tested with the untrained eye showed reversed peak shifts in the direction of S?. These findings are consistent with the hypothesis that the mirror image of S? in angularity gradients functions to reduce the likelihood of the peak shift and area shift along the angularity dimension in pigeons, and question the use of the angularity dimension for intradimensional discrimination training and generalization testing.  相似文献   

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Pigeons were trained to discriminate between arrays containing equal numbers of two different elements as S+, and arrays which contained more elements of one kind than the other as S?. They were then tested with the full range of the proportions of the two elements. This resulted in behavioral contrast and peak shift, as the pigeons responded more to arrays containing more positive than negative elements than they did to the positive training arrays. These findings were obtained with elements that differed in color (blue vs. red dots) and with elements that differed in orientation (horizontal vs. vertical rectangles). The results indicate that the stimulus control exerted by the derived dimension of relative numerosity involves the same processes as the fundamental dimensions that characterize simple stimulus elements.  相似文献   

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Delay eye-blink conditioning is an associative learning task that can be utilized to probe the functional integrity of the cerebellum and related neural circuits. Typically, a single interstimulus interval (ISI) is utilized, and the amplitude of the conditioned response (CR) is the primary dependent variable. To study the timing of the CR, an ISI shift can be introduced (e.g., shifting the ISI from 350 to 850 ms). In each phase, a conditioned stimulus (e.g., a 400- or 900-ms tone) coterminates with a 50-ms corneal air puff unconditioned stimulus. The ability of a subject to adjust the CR to the changing ISI constitutes a critical timing shift. The feasibility of this procedure was examined in healthy human participants (N = 58) using a bidirectional ISI shift procedure while cortical event-related brain potentials were measured. CR acquisition was faster and the responses better timed when a short ISI was used. After the ISI shift, additional training was necessary to allow asymptotic responding at the new ISI. Interestingly, auditory event-related potentials to the CR were not associated with conditioning measures at either ISI.  相似文献   

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柯西不等式新推广与循环不等式校正对偶推广   总被引:6,自引:3,他引:3  
给出了柯西不等式的一个新推广,并给出了循环不等式的一个校正性推广及其对偶推广。  相似文献   

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This is a comparative study of English language education in Japan and Singapore and the role English plays in both countries. English language education in Japan has not been very effective. Although the communicative approach to teaching English was introduced in the 1980s, schools still use the grammar-translation method and most Japanese do not possess the communicative skills necessary for interacting with foreigners. Government rhetoric has also been hesitant in encouraging the learning of English due to concerns about English becoming a threat to the Japanese language and Japanese identity. This paper uses the case study of the Singaporean Chinese to point out that unlike in the Singaporean case, the chances of the Japanese shifting towards the English language and the values associated with it are relatively low.  相似文献   

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This study explored progression of students’ level of reasoning and generalization in numerical and figural reasoning approaches across grades and in different pattern generalization types. An instrument that included four figural patterns was administered to a sample of 1232 students from grades 4 to 11 from five private schools. The findings suggest that there was progressive development in the level of reasoning and generalization in each reasoning approach across clusters of grades. The level of reasoning and generalization in figural approach was higher than that for numerical approach in each grade. In addition, the level of reasoning and generalization for each approach and in each grade was not limited to one level but to several levels. The type of generalization influenced the progression of students’ level of reasoning and generalization in each approach.  相似文献   

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Explanation and generalization in young children's strategy learning   总被引:2,自引:0,他引:2  
Children often learn new problem-solving strategies by observing examples of other people's problem-solving. When children learn a new strategy through observation and also explain the new strategy to themselves, they generalize the strategy more widely than children who learn a new strategy but do not explain. We tested three hypothesized mechanisms through which explanations might facilitate strategy generalization: more accurate recall of the new strategy's procedures; increased selection of the new strategy over competing strategies; or more effective management of the new strategy's goal structure. Findings supported the third mechanism: Explanations facilitated generalization through the creation of novel goal structures that enabled children to persist in use of the new strategy despite potential interference from competing strategies. The facilitative effect of explanation did vary with children's age and did not vary between explanations children created by themselves versus explanations they learned from the experimenter.  相似文献   

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诠释学研究中的拓展与泛化   总被引:1,自引:0,他引:1  
近年来,中国诠释学研究在不断拓展的同时,出现了一种脱离诠释学本有语境的“泛化”倾向:或者把仅仅属于前诠释学形态的理解理论直接当成诠释学;或者把某些潜在的诠释学思想因素或理论萌芽放大为系统的诠释学理论;或者对“文本”作了过于宽泛的理解,使一切理解的对象都“文本化”,最终也就使任何涉及理解问题的理论都变成了“诠释学”。  相似文献   

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In this research article, I present evidence of the existence of visual templates in pattern generalization activity. Such templates initially emerged from a 3-week design-driven classroom teaching experiment on pattern generalization involving linear figural patterns and were assessed for existence in a clinical interview that was conducted four and a half months after the teaching experiment using three tasks (one ambiguous, two well defined). Drawing on the clinical interviews conducted with 11 seventh- and eighth-grade students, I discuss how their visual templates have spawned at least six types of algebraic generalizations. A visual template model is also presented that illustrates the distributed and a dynamically embedded nature of pattern generalization involving the following factors: pattern goodness effect; knowledge/action effects; and the triad of stage-driven grouping, structural unit, and analogy.  相似文献   

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This work is concerned with developmental changes in the structure of classifications. The central claim is that young children's undifferentiated perceptions of complex stimuli are highly structured by wholistic similarity whereas older children's perceptions are structured by component dimensions. It is shown in 2 experiments that young children systematically and spontaneously generalize a category if it is well organized by overall similarity but not if it is organized by a criterial dimension. Older children, on the other hand, spontaneously apprehend and extend a category by its dimensional structure. The third experiment was designed to test the hypothesis that criterial property categories are preferred in classification tasks requiring the explicit discovery of a general rule. It was found that younger children's attention to the dimensional relations within a category increases under rule-discovery instructions, although they still have difficulty ignoring wholistic similarity relations. The trend from similarity to dimensional classification is discussed in the context of Piagetian classification tasks and family-resemblance accounts of natural categories.  相似文献   

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Ten rats were trained in a temporal generalization task (the peak procedure) with variations in the time of reinforcement, the intertrial interval, and the mean and variance of the duration of nonfood trials. There were three types of asymmetry in the temporal generalization gradients: positive skew, secondary rise, and positive asymptote. Asymmetrical gradients can occur as a result of asymmetrical sources of variance, multiplicative combinations of symmetrical sources of variance, and effects of anticipation of the end of a trial and the conditions of the next trial. Ten additional rats were trained with a single time of reinforcement, a limited time of reinforcement availability, long and fixed durations of nonfood trials, and a nonresponse requirement for ending a trial. These conditions markedly reduced all asymmetrical sources of variance and led to very symmetrical gradients. These results demonstrate that none of the asymmetrical sources of variance necessarily has a substantial influence on observed temporal generalization gradients.  相似文献   

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Perceptron models have been used extensively to model perceptual learning and the effects of discrimination training on generalization, as well as to explore natural classification mechanisms. Here, we assess the ability of existing models to account for the time course of generalization shifts that occur when individuals learn to distinguish sounds. A set of simulations demonstrates that commonly used single-layer and multilayer perceptron networks do not predict transitory shifts in generalization over the course of training but that such dynamics can be accounted for when the output functions of these networks are modified to mimic the properties of cortical tuning curves. The simulations further suggest that prudent selection of stimuli and training criteria can allow for more precise predictions of learning-related shifts in generalization gradients in behavioral experiments. In particular, the simulations predict that individuals will show maximal peak shift after different numbers of trials, that easier contrasts will lead to slower development of shifted peaks, and that whether generalization shifts persist or dissipate will depend on which stimulus dimensions individuals use to distinguish stimuli and how those dimensions are neurally encoded.  相似文献   

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主动时态数据库中事件的时态语义研究   总被引:1,自引:0,他引:1  
在事件时态一致性的前提下详细讨论了主动时态数据库中事件的时态问题,给出了复合时态事件的时态关系以及任意两个事件之间的Allen关系.  相似文献   

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Prior research indicated that a training sequence consisting of a negative stimulus followed by a positive stimulus constitutes the minimal condition for the production of postdiscrimination phenomena typically observed after training with random sequences of the discriminanda. The present experiments, employing multiple schedules with pigeon subjects, confirmed the earlier findings but indicated that they are restricted to procedures in which the reinforcing stimulus may acquire a discriminative function that competes with the control exerted by the nominal discriminanda. The sequences in which the discriminanda were presented did not differentially affect subsequent measures of generalization and transfer if the discriminative function of reinforcement were degraded either by introducing some reinforcers during the negative stimulus (Experiment 1) or by omitting some reinforcers during the positive stimulus (Experiment 2). It was concluded that the sequence in which the discriminanda are presented during discrimination training does not contribute fundamentally to the processes responsible for discrimination formation with random training sequences.  相似文献   

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Four naive pigeons were given six generalization tests in extinction after periods of pretraining in which S+ appeared with food reinforcement and S? appeared in extinction. An analysis of sequential effects among presentations of test stimuli showed that the overall gradient was influenced differently by stimuli at the extremes of the continuum of test stimuli and by S+ and adjacent stimuli. Gradients consisting of responding in each stimulus when it was preceded by an extreme stimulus tended to peak at S+, while gradients produced when each stimulus was preceded by S+ or an adjacent stimulus tended to show a peak shift. This was true whether the overall gradient showed a peak shift or not. Two naive subjects were added and four additional tests were given after pretraining in which unequal frequencies of reinforcement accompanied both S+ and S?. Results of all 10 tests show that sequential effects occur during generalization testing in extinction and that these “local dimensional effects” are unlike local contrast. These stimulus-specific sequential effects may greatly influence overall gradient form.  相似文献   

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Cognitive and behavioral theories in psychology have failed to explain adequately the commonly reported failures in generalization exhibited by mentally retarded populations. This article provides background on generalization as viewed by behavior and cognitive psychologists, describes the failures to facilitate generalization, and offers an alternative explanation of such failures. This explanation describes the generalization process in terms of individual capacity for analogical reasoning.  相似文献   

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首先给出由—扑克牌游戏规则产生的问题,进而利用(0,1)-矩阵方法对此问题作了数学推广与理论分析:即重排数g(m,n)及其存在性,最后给出g(m,n)求解算法与求解公式。  相似文献   

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