Feature extinction enhances transfer of occasion setting

In three experiments, transfer effects in appetitive serial feature-positive discrimination procedures (X→A+,A?) were examined with rat subjects. Nonreinforced presentations of the feature (X) alone had little or no effect on that cue’s ability to modulate responding to the target cue with which it had originally been trained (A) but enhanced its ability to modulate responding to another cue (B), which had been the target within another serial feature-positive discrimination (Y→B+,B?). These effects were observed when the nonreinforcedX presentations occurred either concurrently withX→A+,A? training or afterward. Regardless of whether or not nonreinforcedX presentations were administered,X did not modulate responding evoked by a cue that had not been trained within a serial feature-positive discrimination. These data help resolve conflicts in published reports of transfer or its absence in this conditioning situation, and shed light on the nature of the modulatory or occasion-setting powers of feature cues in serial feature-positive discrimination learning.     

Higher order occasion setting

Higher order occasion setting with serially presented stimuli was investigated in an appetitively motivated, discrete-trial operant study with rats. Reinforcement of barpressing during an occasion-setting light (a discriminative stimulus) was contingent on immediately preceding second-order occasion setters (i.e., a click train or a buzzer served as a conditional discriminative stimulus). Moreover, the meanings of the clicks and buzzer were themselves indicated by a third-order occasion setter that preceded them (i.e., a white noise acted as a second-order conditional discriminative stimulus). Subjects responded more frequently and had shorter latencies to the first response in the presence of the light on trials during which barpressing was reinforced than on trials during which barpressing was not reinforced. The likelihood that the subjects solved the problem by responding to unique compound stimuli was minimized by the insertion of a 5-sec gap between the different controlling stimuli presented on each trial. Thus, these subjects appear to have mastered a second-order conditional discrimination, which is equivalent to third-order occasion setting if the discriminative stimulus (light) is viewed as a first-order occasion setter. Although the subjects learned to respond appropriately to each of the compound stimuli, differences in responding to specific stimuli were consistent with a higher order feature-positive effect. Some implications of higher order occasion setting are discussed, including the issue of independence between the different levels of occasion setting signaled by a single stimulus.     

Temporal determinants of occasion setting in feature-positive discriminations

Three experiments examined the acquisition and transfer of Pavlovian feature-positive discriminations (XA+, A?) in rat subjects. To identify the nature of the associations formed in those discriminations, the form of the conditioned responses (CRs) was examined. If the feature,X, and common element, A, cues started and ended together onXA compoud trials, associations betweenX and the food unconditioned stimulus (US) were acquired. If the onsets and/or terminations ofX preceded those of A,X acquired the ability to set the occasion for responding to A, that is, A evoked CRs only onXA compound trials. The acquisition of occasion setting was favored when (1) the onset of X preceded that of A, (2) the interval betweenX and A and/or the US was relatively long, and (3) the termination ofX occurred prior to the onset of A. The occasion-setting power ofX was fairly specific to A:X did not modulate responding evoked by another cue that had been first trained and then extinguished or by a cue that had been paired with the US only a few times. However,X did enhance responding to a cue that had been a common element in another, identical feature-positive discrimination. That transfer was somewhat greater if theX and A terminated together than ifX terminated prior to the onset of A. Implications for theories of stimulus control in Pavlovian conditioning are discussed.     

Negative priming and occasion setting in an appetitive Pavlovian procedure

Rats received training in which two auditory target stimuli, X and Y, were signaled by two visual stimuli, A and B, and followed by food (i.e., A-->X+, B-->Y+). The test consisted of presentations of X and Y preceded either by the same signal as during training (same trials: A-->X, B-->Y) or by the alternative signal (different trials: A-->Y, B-->X). After 8 training sessions, the animals responded less on same trials than on different trials; this effect was significantly reduced after 24 training sessions. In two additional experiments, animals that had also experienced presentations of A and B alone, either before or during training, showed the opposite pattern of results, responding more on same trials than on different trials. These results are interpreted as being due to the interaction between the effects of occasion setting and negative priming (see Wagner, 1981).     

Transfer of occasion setting: The role of generalization decrement

In Experiment 1, pigeons were trained on two feature-positive discriminations. A transfer test examined whether the feature from one discrimination enhanced responding to the target from the other. Transfer was obtained, but it was incomplete; the feature produced less responding to the transfer target than to its own. Experiments 2 and 3 examined whether this attenuation of responding was the product of generalization decrement induced by the novel combination of feature and target on transfer trials. Birds were trained on a pair of pseudo-occasion-setting discriminations in which each target was reinforced whether or not it was preceded by its feature. In a subsequent test, there was no loss of responding when novel combinations of features and targets were introduced; on the contrary, responding was, if anything, enhanced in this condition. This suggests that imperfect transfer is not due to generalization decrement but to the fact that an occasion setter is specific to its target stimulus.     

Evidence for the interchangeability of an avoidance behavior and a negative occasion setter

Recent research on avoidance behavior provided evidence that such behavior can function as a negative occasion setter. We tested this hypothesis further by investigating whether the modulatory function of a stimulus occasion setter transfers selectively to a relation previously modulated by an avoidance behavior, and whether the modulatory function of an avoidance behavior transfers selectively to a relation previously modulated by a stimulus occasion setter. The three experiments reported in this article provided evidence to support this hypothesis. Furthermore, the results of Experiment 1 suggested that the presence of counterconditioning trials is not a necessary condition for an avoidance behavior to function as a negative occasion setter. All three reported experiments support the occasionsetting account of avoidance behavior.     

与求和矩阵

构造一个多项式递归序列,得到n∑i=1[a (i-1)d]m的一种求法,使求和矩阵n∑i=1im的计算成特殊情况.     

英语写作"文化负迁移"现象探析与规避策略

写作是衡量语言学习者综合运用语言能力高低的重要体现。文章从词汇、句法、语篇三个层面分析了英语写作中的母语文化负迁移现象及其产生原因，并提出规避策略：强化文化意识，加强文化对比，学会英语思雏和注重写作实践。     

Studies of negative pragmatic transfer in interlanguage pragmatics

1.Negative pragmatic transfer and its role in interlanguage pragmaticsInterlanguage pragmatics ( IL P) is a new branch of pragmatics. Itis a pragmatic perspective intothe learner‘s language. As such,it specifically tackles how learners comprehend and produce utter-ances in a target language ( TL) .L earners always use their previous knowledge,experience,skill,etc. in learning to understandand produce meanings in a new situation and with the target language they have learned. Technically,this is referred to ...     

汉语负迁移对英语教学的影响及对策

我国英语学习者缺乏真实的英语语言环境,并且受到汉语的影响,常常把汉语的规则迁移到英语学习中,导致了母语负迁移的产生,造成英语表达错误。本文在简单介绍语言迁移理论的基础上,分析了汉语在英语学习中的负迁移现象,提出减少汉语负迁移的策略。     

The negative transfer of native culture in intercultural communication

In intercultural communication,the negative transfer of native culture is a universal phenomenon that may induce communicative barriers,misunderstandings and even conflicts.This paper touches upon the nature and causes of the negative transfer of native culture,and elucidates cultural empathy as one way to diminish such negative transfer with the purpose of improving intercultural communication quality.     

数项级数求和方法与技巧

本文利用数学分析、复变函数、线性代数、数论、组合数学等方面的知识，归纳总结了数项级数求和的若干方法和技巧，它对提高有关级数理论方面的教学质量是有帮助的．     

How do we learn in a negative mood? Effects of a negative mood on transfer and learning

Findings show that both positive and negative mood may hinder or promote information processing. In two experiments, we show that negative mood impairs transfer effects and learning. In the first experiment, N = 54 participants drawn from a training course for the Swiss Corps of Fortification Guards first learned to solve the three- and four-disk Tower of Hanoi (ToH) problem to mastery level. After mood induction, they were asked to solve one proximal (five-disk ToH) and two distal transfer tasks (the Missionary and Cannibal Problem and the Katona Card Problem). Participants in a negative mood solved the transfer tasks less efficiently. In the second experiment, this result was replicated with a sample of N = 80 participants drawn from a training course for nurses. Additionally, mood affected performance if it was induced before the learning phase; participants in a negative mood needed more repetitions to reach the mastery level and also performed worse in the transfer tasks, although there were no greater mood differences in this problem-solving phase. The implications for the design of learning settings are discussed.     

汉译英错句中的汉语负迁移分析

母语和第二语言的学习有着必然的共性,又有着截然不同的差异。母语迁移对第二语言学习有着不可低估的影响。学生学习过程中出现一些错误是自然的,而且也是不可避免的。本文从语言迁移的角度,分析汉译英错句中的汉语负迁移现象,以便学生摆脱母语干扰,充分利用母语知识迁移加强对英语知识的掌握。     

浅析英语翻译实践中的母语负迁移

在英语翻译实践中,母语迁移是一种比较常见的现象.母语负迁移,是指作为源文的母语和目的语之间在结构等方面所具备的差异性,会阻碍对目的语的准确翻译.本文从词汇、句法、篇章结构方面分析了母语对英语翻译负迁移主要表现,接着探讨了在英语翻译实践中避免母语负迁移的策略.     

谈英语及对外汉语教学中的负迁移现象

无论是在以英语还是以汉语作为第二语言的学习过程中，都会不同程度地存在着第一语言对第二语言的影响，本文着重探讨其中的负面影响，即负迁移。负迁移的形成是由于英、汉两种语言的差异，甚至过度相似性或是由于学习者在学习过程中过度借助或照搬第一语言的知识而造成的，在此，笔者主要从英、汉两种语言及思维差异的角度，分析了实际教学中各个平面的负迁移现象，包括语义、语法结构、语用等各层面上的负迁移。根据分析结果，笔者提出具体教学中避免负迁移产生的相关对策：（1）重视第一、第二语言的对比分析；（2）以科学的态度看待语言学习过程中的语言错误现象。     

刍议赣方言在英语语音习得中的负迁移现象

赣方言母语会对习得英语发音产生的负迁移作用;所以教学中要分析赣方言区学生典型的英语语音错误及其成因.     

Summation and overexpectation with qualitatively different outcomes

In five experiments, a Pavlovian appetitive conditioning preparation was used with rats to explore the interaction of associations with different, but equivalently valued, outcomes. Experiment 1 demonstrated summation in magazine responding when two stimuli previously associated with different outcomes were combined. Experiments 2A and 2B found that pairing that stimulus compound with one of the outcomes led to a decrease in performance (overexpectation) for both of the stimulus elements. Experiments 3A and 3B confirmed that result but demonstrated the continued presence of the original stimulus-outcome associations. The results are consonant with a view in which replacing one outcome with another leads to an associative structure containing both stimulus-outcome associations and an outcome-independent depressive process.     

组合求和

给定一个集合X,X的满足某种条件的子集构成一个集合X^＊,对X^＊中的任何一个子集A,定义一个由X＊到R的函数f（A）,计算∑A∈X^＊f（A）,我们称这样的求和问题为组合求和.     

测量电阻方法小结

近几年理科综合考试中,电学实验题频频出现,且对灵活迁移能力要求有越来越高的趋势。从电学实验的命题内容看,电阻的测量是其中最热的考点之一。以下就测量电阻方法作个小结。1用多用电表Ω档直接测量电阻(不再细述)2伏电安路法如测右量图电,测阻量值R=Rx RA,测量值偏大,适宜于测量大电阻(RxRA)。电路如右图,测量值R=RVRx/(RV Rx),测量值偏小,适宜于测量小电阻(RVRx)。小结一:用多用电表Ω档、伏安法,通常用于测量普通电阻Rx。3仪表的非常规运用,测量电阻(例1)1安培有内阻已知的,可当作伏特表使用如图示,已知安培表A1的内阻RA1,要…