Leibniz's complete propositional logic

Conclusion I have shown (to my satisfaction) that Leibniz's final attempt at a generalized syllogistico-propositional calculus in the Generales Inquisitiones was pretty successful. The calculus includes the truth-table semantics for the propositional calculus. It contains an unorthodox view of conjunction. It offers a plethora of very important logical principles. These deserve to be called a set of fundamentals of logical form. Aside from some imprecisions and redundancies the system is a good systematization of propositional logic, its semantics, and a correct account of general syllogistics. For 1686 it was quite an accomplishment. It is a pity that Leibniz himself did not fully appreciate what he had achieved. It does seem to me that this was due in part, as the Kneales urge (Note 4), to his having kept the focus of his attention on traditional syllogistics. It is a great pity that he did not polish GI 195–200 for publication. The publication of GI 195, 198, and 200 would have most likely promoted further research.This paper was conceived in a Seminar on the Generales Inquisitiones offered by Professor Klaus Jacobi at the University of Freiburg during the 1987 winter semester. I am grateful to him for having allowed me to participate in that exciting seminar. I am grateful to all the seminar participants, especially to Professor Jacobi, Professor Klaus Erich Kaehler, Doctor Helmut Pape, and Herr Hans-Peter Engelhart for sustained and illuminating discussions of some passages of the GI. Jacobi was extremely kind in reading the second version of this paper with a highly refined comb. I am most grateful to him for having pointed out typos, stylistic infelicities, and conceptual obscurities. He also provided advice on the translation, and, most generously and cooperatively, offered suggestions for improving the exposition and the arguments.     

Beyond belief bias: Reasoning from conceptual structures by mental models manipulation

Mental models constitute an alternative to the rule-based systems in the explanation of human reasoning (Johnson-Laird, 1983). In this paper, we claim that the concept of believability generally used to categorize content and context effects is of little use within a semantic theory. Thus, we propose the use of categories that are directly extracted from subjective relations among concepts within the reasoning problem. We demonstrate that manipulations based on this kind of categorization produce predictable patterns of responses in reasoning problems. We present two experiments to test our predictions, using conditional and syllogistic reasoning problems, and in both cases, we demonstrate the influence of conceptual knowledge not only in natural contexts, but also in experimentally created artificial contexts.     

Text Comprehension Training for Disabled Readers: An Evaluation of Reciprocal Teaching and Text Analysis Training Programs

Forty-six reading disabled adolescents were randomly assigned to one of three 25-hr instructional programs. Two programs provided training in expository text comprehension, and a third offered training in academic problem solving and organizational and study skills (an alternative treatment control). One reading comprehension program was designed to remediate a deficient knowledge base, forcing disabled readers to elaborate and further process new text knowledge, focusing on both specific informational content in a text and knowledge of text structure per se. The second program was patterned after the Palincsar and Brown (1984) reciprocal teaching techniques and focused on training four text comprehension strategies used by skilled comprehenders. Both the “knowledge-base” and the “strategy” training approaches were associated with significant improvement in disabled readers' comprehension skills, although training effects did not generalize across all aspects of reading comprehension performance. Strategy-trained readers applied the trained strategies with equal success on instructed and uninstructed text materials, providing strong evidence of transfer of learning. Knowledge-base readers also demonstrated successful transfer of specifically trained procedures (semantic mapping, text analysis) to unfamiliar text. In both programs, the best outcomes were obtained when specific strategies and operations were targeted for training.     

死亡凸显对自我姓名注意瞬脱对抗效应的影响

已有研究表明死亡凸显会抑制自我面孔和自我参照记忆加工的自我优势,可是死亡凸显对自我姓名的影响尚不明确,本研究采用事件相关电位技术,探索死亡凸显对自我姓名注意瞬脱对抗效应及其大脑神经活动的影响。58名被试在经历不同的启动任务后,完成自我姓名、朋友姓名和名人姓名的注意瞬脱任务。行为结果发现自我姓名识别正确率显著高于朋友姓名和名人姓名,表现出稳定的自我姓名加工的注意瞬脱对抗效应;电生理数据发现死亡启动后自我姓名诱发的P300波幅显著低于消极启动组和中性启动组,而朋友姓名和名人姓名并不受启动的影响。本研究结果与以往研究结果共同表明死亡想法凸显会使个体将抑制自我加工（自我姓名、自我面孔和自我参照记忆）作为应对远端死亡焦虑的一种手段。     

Aptitude Tests: Can We Predict Their Future?

Garcia, J. The Logic and Limits of Mental Aptitude Testing. American Psychologist, 1981, 36, 1172–1180. Hargadon, F. Tests and College Admissions. American Psychologist, 1981, 36, 1112–1119.     

Disintegrated experience: the dissociative disorders revisited

We present proposed changes to the dissociative disorders section of the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders and review the concept of pathological and nonpathological dissociation, including empirical findings on the relations between trauma and dissociative phenomenology and between dissociation and hypnosis. The most important proposals include the creation of two new diagnostic entities, brief reactive dissociative disorder and transient dissociative disturbance, and the readoption of the criterion of amnesia for a multiple personality disorder diagnosis. We conclude that further work on dissociative processes will provide an important link between clinical and experimental approaches to human cognition, emotion, and personality.     

Visual symmetry recognition by pigeons

Summary Pigeons learned to discriminate a large number of bilateral symmetric and asymmetric visual patterns successively projected on the pecking-key of an operant conditioning chamber. Responses to the positive stimuli were reinforced according to a variable interval schedule. Once acquisition was complete generalization trials, involving sets of new stimuli, were instituted under extinction. The birds classified these novel test stimuli with high accuracy throughout, according to their symmetry or asymmetry. Their performance was not disturbed by sets of test stimuli whose geometrical style differed considerably from the training stimuli. Pigeons were even able to discriminate when only allowed the use of one eye. The generalization series were partly designed to test some classical symmetry recognition theories. None was found to be adequate. Subsidiary experiments suggested that most pigeons have a slight spontaneous preference for asymmetric patterns and that symmetry/asymmetry differences can aid pattern discrimination learning at an early stage. It is concluded that pigeons, much like humans, can discriminate bilaterally symmetric from non-symmetric visual forms in a concept-like, generalizing way. The ontogenetic and phylogenetic development of this competence is considered. A novel symmetry recognition hypothesis based on spatial frequency analysis and neuronal feature-detector considerations is proposed.     

Demonstration of an aftereffect occurring in the tactile-kinesthetic domain

Summary The aim of this work is the demonstration of a tactile-kinesthetic aftereffect. A sequence of stimuli was offered to adult subjects whose task was to compare two weights presented simultaneously to both hands by means of a Piéron gravimeter. In Experiment 1 the inspection stimuli consisted of two successive presentations of unequal weights for a period of 2 × 10 s. The test stimuli consisted of two equal weights rapidly following an inspection stimulus. Control stimuli consisting of two equal weights not preceded by an inspection stimulus were interspersed in the sequence. The results obtained confirm the existence of a contrast effect after presentation of an inspection stimulus. In Experiment 2 the inspection stimuli consisted of a single presentation of two unequal weights for a period of 20 s. The results confirm those of the first experiment and provide data enabling the contrast effect obtained to be interpreted as a Köhler-type aftereffect. In order to avoid confusion with the kinesthetic-figural aftereffect, we propose to call the effect demonstrated here the Gravimetric Aftereffect.     

Perception,belief, and the structure of physical objects and consciousness

Conclusion We have now provided an overall simple theoretical account of the structure of perceptual experience proto-philosophically examined in Part I. The next task is to find the proper logical machinery to formulatte those accounts rigorously.This essay is an abridgment of a monograph written while the author enjoyed both a 1975–76 sabbatical leave from Indiana University and a concurrent grant from the National Endowment for the Humanities for doing research in metaphysics.