Reinforcement and punishment in a closed system

Children chose between toys freely and with various restrictive contingencies. Sometimes play with a preferred toy was contingent on play with a nonpreferred toy. Sometimes play with a nonpreferred toy was contingent on play with a preferred toy. Another toy (free toy) was always available during contingency sessions. Because toy playing occupied the entire session the response system was closed. When one response increased in duration others had to decrease. An analysis of closed-system responding revealed that the restrictions of the closed system together with the restrictions imposed by the contingencies forced subjects to alter the proportion of time devoted to the three responses. A geometrical model representing the closed system and an analytical method based on distance are presented to describe the data.     

Stimulus control and delayed reinforcement

Pigeons were tested for generalization along the line-orientation dimension, after being trained on various two-component multiple schedules. The first component contained either a variable-interval 1-min schedule of immediate reinforcement or an extinction schedule and was associated with a plain white key (S1). The second component contained a variable-interval 1-min schedule of delayed reinforcement and was associated with a black line on a white background (S2). The major results showed that (a) decremental gradients were obtained around the stimulus associated with the delayed reinforcement component when S1 was associated with extinction, but that incremental gradients were obtained when S1 was associated with immediate reinforcement, (b) the subjects' pretraining did not affect the generalization gradients if sufficient training on the terminal multiple schedule was provided, and (c) changing the S1 schedule from immediate reinforcement to extinction produced behavioral contrast if reinforcement was delayed for 10 sec during S2, but not if it was delayed for 20 sec.     

The advantages of mathematical modeling over traditional methods in the analysis of category clustering

A mathematical model for the analysis of category clustering is developed and testd. The model, which can be applied to categories of any size, is an extension of a two-item statistical model developed by Batchelder and Riefer (Psychological Review, 1980, 87, 375–397), and is equivalent to their model when categories consist of two items. The model is based on a current theory of clustering which postulates that the learning of a list of category items occurs on different hierarchical levels. Two category list-learning experiments are presented, and the data from these experiments are analyzed using the general statistical model. The first experiment reveals that the probabilities of storing and retrieving a cluster increase with category size, while the learning of items as singletons decreases. The effects of within-category spacing indicate that the storage of clusters decreases while cluster retrievability increases with an increase in input spacing. In the second experiment, the storage and retrieval of clusters are shown to be unaffected by whether the presentation of items is uncued or cued with the name of the category. However, the association of items decreases and the learning of items as singletons increases with uncued presentation. In the final sections, the general statistical model is compared to other methods for the measurement of category clustering. The model is shown to be superior to numerical indices of clustering, since these measures are not based on any theory of clustering, and because unitary measures cannot capture the multiprocess nature of categorized recall. The model is also argued to have certain advantages over other mathematical models that have been applied to category clustering, since these models cannot account for situations in which a portion of the items are clustered while others are learned singularly.     

Hemiplegic writing in severe aphasia

Three patients with severe aphasia and right hemiplegia are described who could write to dictation with the right arm using a limb prosthesis though agraphic with the "intact" left hand. The phenomenon of "hemiplegic writing" is explained as an access to submerged or preprocessing levels in language and action structure, through the use of older proximal motor systems. This interpretation has implications for our understanding of language and brain function, as well as for approaches to the treatment of patients with severe language disorders.     

Different methods of lexical access for words presented in the left and right visual hemifields

Right-handed adults were asked to identify by name bilaterally presented words and pronounceable nonwords. For words in the normal horizontal format, word length (number of letters) affected left visual hemifield (LVF) but not right visual hemifield (RVF) performance in Experiments 1, 2, 3, 5, and 6. This finding was made for words of high and low frequency (Experiment 6) and imageability (Experiment 5). It also held across markedly different levels of overall performance (Experiments 1 and 2), and across different relative positionings of short and long words in the LVF and RVF (Experiment 3). Experiment 4 demonstrated that the variable affecting LVF performance is the number of letters in a word, not its phonological length. For pronounceable nonwords (Experiment 7) and words in unusual formats (Experiment 8), however, length affected both LVF and RVF performance. The characteristics identified for RVF performance in these experiments also hold for the normal reading system. In this (normal) system the absence of length effects for horizontally formatted words is generally taken to reflect the processes involved in lexical access. Length effects in the normal reading system are thought to arise when lexical access for unusually formatted words and for the pronunciation of nonwords requires the short-term storage of information at a graphemic level of analysis. The characteristics of LVF performance indicate that horizontally formatted words presented to the right cerebral hemisphere can only achieve lexical access by a method that requires the short-term storage of graphemic information. This qualitative difference in methods of lexical access applies regardless of whether the right hemisphere is seen as accessing words in the left hemisphere's lexicon or words in a lexicon of its own.     

Ronald Dworkin on Abortion and Assisted Suicide

In the first part of this article, I raisequestions about Dworkin's theory of theintrinsic value of life and about the adequacyof his proposal to understand abortion in termsof different ways of valuing life. In thesecond part of the article, I consider hisargument in ``The Philosophers' Brief on AssistedSuicide', which claims that the distinctionbetween killing and letting die is morallyirrelevant, the distinction between intendingand foreseeing death can be morally relevantbut is not always so. I argue that thekilling/letting die distinction can be relevantin the context of assisted suicide, but alsoshow when it is not. Then I consider why theintention/foresight distinction can be morallyirrelevant and conclude by presenting analternative argument for physician-assistedsuicide.     

“AFTER THE EVENT”: FREUD'S UNCANNY AND THE ANXIETY OF ORIGINS

This essay aims to revise Freud's theory of the uncanny by rereading his own essay of that name along with the key material Freud drew on in formulating his theory: E. T. A. Hoffmann's short story “The Sandman” (1816a) and Ernst Jentsch's essay “On the Psychology of the Uncanny” (1906a). While arguing, initially, both that Jentsch's work is fundamentally misconstrued by Freud and that it offers a better account of what happens in Hoffmann's story, the essay moves beyond Jentsch's account to offer a more philosophically oriented theory of the uncanny, one more in line with Freud's ideas in Beyond the Pleasure Principle (1920a).     

儿童发展与电子媒体：基于生态科技微系统理论的视角

电子产品改变了人们社会活动的模式和生活方式,其低龄化使用也不可避免地影响和塑造了儿童的发展。生态系统理论认为儿童的发展源于儿童与周围环境之间不断的交互作用。生态科技微系统理论是在当今电子科技的环境下以生态系统理论为背景框架提出的解释电子媒体对儿童发展影响的理论模型。电子产品作为儿童学习、娱乐、沟通和展示自我的工具,对儿童的认知方式、情感互动方式和参与社会的方式等都会产生一定的影响。这些影响依赖于三个相互独立又关联的因素之间的作用：儿童自身的特点、电子媒体的内容和特点,以及儿童媒体使用的环境。未来的研究可以从研究手段和研究内容上进一步深化以探讨电子产品的使用和儿童发展的关系。     

明清时期儒学东渐日本简论

明清时期是中国儒学东传日本的高潮时期 ,日本思想家全面接受和吸取了儒学思想 ,并结合日本国情加以阐释和创新 ,将传统的儒学思想融入日本社会各个层面 ,对日本文化发展及其社会进步起了重要作用。同时 ,也产生了某些消极因素。     

前瞻记忆意向后效应的年龄差异

前瞻记忆意向后效应会对日常生活产生负面影响,研究发现这种现象在老年人中尤其突出。近些年来,研究者们从内外两方面对影响前瞻记忆意向后效应年龄差异的因素进行了探讨,了解到认知老化所带来的抑制能力的衰退以及短时记忆缺陷是造成其年龄差异的主要原因。未来研究需进一步拓展对认知老化的机制和抑制控制能力的认识。另外,可以采用事件相关电位（Event-Related Potentials, ERPs）和功能性磁共振成像（Functional Magnetic Resonance Imaging, fMRI）等脑成像技术揭示前瞻记忆意向后效应年龄差异的加工机制及神经机制。