甘岑的自然演绎演算

迄今为止,我们所主要讨论的逻辑演算,即用公理方法处理的狭谓词演算,标志着把数学方法运用于逻辑获得了显著的成功。这种演算的形式上的简易是令人称道的,从纯粹数学的观点看,它可以同公理化的射影几何及抽象群论这一类数学观念的完满体现的学科相媲美。此外,作为应用于研究演绎系     

《主体·客体·认识》中译本序言

B·A·列克托尔斯基是苏联著名的马克思主义哲学家,现任苏联《哲学问题》杂志主编、科学院哲学所认识论研究室主任。《主体·客体·认识》一书是他的一本有相当高学术价值、享有国际盛名的力作,已被翻译为七种文字。本文系他为该书中译本写的前言,其中谈了对认识论发展的重要看法。该书中译本由贾泽林等人译,将由中国人民大学出版社出版。     

空间能力研究的历史背景

定义空间能力的方式多种多样,致使我们难以将其含义精确地归结为某一术语。有些学者广义地把空间能力描述为在那些非语言信息加工中的个体差异,而另一些学者则狭义地把它描述为在完成空间测验中的个体差异,由于用以研究空间能力的方法和测量的不同,定义问题变得更为复杂。本文将对空间能力的测量作一简要概述,尽管它类似于因素分析方法学的历史,但由于关系到空间能力的定义,因而,重点在于研究的结果而不在于因素分析方法学的历史本身。     

判断和选择中的认知错觉

人类的错误为研究人类智能的结构和功能提供了有价值的资料。对于记忆的研究多是建立在遗忘的基础上,对知觉的研究常常基于识别力衰退,对于语言和思维的研究已经揭示了失言。关于人类错误的研究格外重要,因为它表明了人类智力的某些局限,它时常暴露出隐藏在人们行为之下的规律和机制,它常常提示出可以改善人们表现的方式。错觉是一种特殊的错误,它特别令人困惑,因为人们造成的这种错误始终具有迷惑力,甚至当人们已彻底认识到这是一种错误时亦然。例如,我们会感到在图1中右边的线     

共产主义实验在苏联

1.斯大林个人扭曲了的共产主义意识形态“斯大林主义”,是苏联官方理论家从不使用的一个术语。而且,它一般也并没有被人们广泛地当作马克思-列宁主义来运用。有时候,斯大林主义被误解为是马列主义的一种扩大或发展。实际上,斯大林主义倒可以看作是从马列主义中派生出来并且背离了马列主义的,它(直到1953年斯大林去世时     

系统剪影:作为哲学的一般系统

我对介绍一般系统论有为难和讨厌之感。显然,在我看来,一般系统论者所关注的中心问题即“系统的本质是什么?”基本上是一个哲学问题。然而,我所接触的一般系统论者不仅没提及哲学,而且似乎把哲学看作废弃的和缺乏时代性的东西(哲学的某些问题很久以前就被逻辑实证主义者取消     

A quantitative analysis of chain-schedule performance

Six pigeons were trained with a chain variable-interval variable-interval schedule on the left key and with reinforcers available on the right key on a single variable-interval schedule arranged concurrently with both links of the chain. All three schedules were separately and systematically varied over a wide range of mean intervals. During these manipulations, the obtained reinforcer rates on constant arranged schedules also frequently changed systematically. Increasing reinforcer rates in Link 2 of the chain increased response rates in both links and decreased response rates in the variable-interval schedule concurrently available with Link 2. Increasing Link-1 reinforcer rates increased Link-1 response rates and decreased Link-2 response rates. Increasing reinforcer rates on the right-key schedule decreased response rates in Link 1 of the chain but did not affect the rate in Link 2. The results extend and amplify previous analyses of chain-schedule performance and help define the effects that a quantitative model must describe. However, the complexity of the results, and the fact that constant arranged reinforcer schedules did not necessarily lead to constant obtained reinforcer rates, precluded a quantitative analysis.     

Effects of relative reinforcer frequency on complex color detection

Pigeons were trained under a discrete-trials detection procedure in which one of a set of color stimuli was presented on the center key and a single response turned off the stimulus and illuminated two side keys. Single responses to one or the other side key produced occasional reinforcers depending on the value of the color stimulus. In Experiment 1, one color-stimulus set comprised 559, 564, 569, and 574 nm, and right-key pecks were occasionally reinforced following presentations of members of this set. The other stimulus set comprised 579, 584, 589, and 594 nm, and left-key pecks were occasionally reinforced following presentations of members of this set. Across seven experimental conditions, the left/(left + right) relative reinforcer frequency was varied from .1 to .9. In Experiment 2, one stimulus set contained only one member, 574 nm, and right-key responses were occasionally reinforced following its presentation. Over 12 experimental conditions, two manipulations were carried out. First, the number of stimuli comprising the other stimulus set was increased from one (579 nm) to two (579 and 584 nm) to three (579, 584, and 589 nm) and to four (579, 584, 589, and 594 nm), and left-key responses were reinforced occasionally following center-key presentations of members of this set. Second, for each stimulus combination, the left/(left + right) relative reinforcer frequency was varied from .1 to .5 to .9 across three experimental conditions. The principal finding of Experiments 1 and 2 was that reinforcers and stimuli interacted in their effects on behavior. In Experiment 3, pairs of adjacent stimuli (5 nm apart) in the range 559 to 594 nm were presented in each experimental condition, and the left/(left + right) relative reinforcer frequency was held constant at .5. The data from all three experiments were analyzed according to a detection model describing performance in multiple-stimulus two-response procedures. This model provided independent measures of stimulus discriminability, contingency discriminability, and bias. The analysis showed that (a) consistent with the color-naming function, pigeons were better able to discriminate between higher nanometer values than lower nanometer values; (b) their ability to discriminate between the stimuli was independent of the number of wavelengths comprising each stimulus set; (c) they allocated delivered reinforcers very accurately to the previously emitted response; and (d) no consistent biases emerged.     

Algorithmic shaping and misbehavior in the acquisition of token deposit by rats

In two experiments, rats were trained to deposit ball bearings down a hole in the floor, using an algorithmic version of shaping. The experimenter coded responses expected to be precursors of the target response, ball bearing deposit; a computer program reinforced these responses, or not, according to an algorithm that mimicked the processes thought to occur in conventional shaping. In the first experiment, 8 of 10 rats were successfully shaped; in the second, 5 of 5 were successfully shaped, and the median number of sessions required was the same as for a control group trained using conventional shaping. In both experiments, “misbehavior,” that is, excessive handling and chewing of the ball bearings, was observed, and when the algorithmic shaping procedure was used, misbehavior could be shown to occur in spite of reduced reinforcement for the responses involved.     

Qualitative dynamics of disordered human locomotion: a preliminary investigation

A qualitative approach to the evaluation of disordered locomotion is introduced within the framework of dynamical systems theory. Exemplar phase plane and angle-angle plots of knee and ankle movements were constructed from limb trajectories of neurologically impaired individuals and qualitatively compared with similar plots, reflecting normal locomotion. In phase plane trajectories of normal locomotion, characteristics of spring-like dynamics dominated the loading and unloading phases whereas those of ballistic pendular dynamics were seen during swing. The overall squareness of the normal phase plane trajectories suggested precisely timed and narrowly focused controls. in contrast, phase plane records from hemiparetic subjects had markedly reduced segmental velocities, pronounced velocity reversals in both stance and swing, and a loss of overall squareness. Knee-ankle plots of normal locomotion revealed important features of intersegmental coordination such as coupled out-of-phase coordination in loading and unloading, a decoupled phase offset in early swing, and a kind of active partitioning in late swing in which one segment moved while the other remained constant. These intersegmental relations were absent or distorted in the hemiparetic angle-angle plots. It is suggested that this qualitative approach, together with electromyography and force dynamics, may allow the characterization of the movement disorders associated with given neuropathologies.