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51.
Toussaint HM Commissaris DA Van Dieeumlant;n JH Reijnen JS Praet SF Beek PJ 《Journal of motor behavior》1995,27(3):225-234
The control of the ground reaction force vector relative to the center of gravity (CoG) was examined while subjects performed a back-lifting task. Six male subjects (aged 24.0 +/- 2.5 years) repeatedly lifted a barbell. A biomechanical analysis that used a linked segment model revealed that the summed rotations of body segments during lifting yielded a specific rate of change of the angular momentum of the entire body. This equaled the external moment provided by Fsubg; relative to CoG. This implies that multisegment movements involve control of the angular momentum of the entire body through an appropriately directed Fsubg;. Thus, in dynamic tasks Fsubg; is pointed away from rather than lined up with the CoG, as is the case in static tasks. 相似文献
52.
Letícia M. Sicuro Corrêa 《Journal of psycholinguistic research》1995,24(3):183-203
Methodological difficulties are identified in the assessment of children's comprehension of relative clauses (RCs) by means of the standard acting-out procedure. An alternative experimental task is proposed which attempts to minimize these difficulties while exploring the advantages of the acting-out technique. An experiment is reported in which Portuguese-speaking 3- to 6-year olds were tested by means of this alternative task. The results show children being affected by both the position and the focus of the RC in the same way adults have been reported to be and an error analysis suggests that most of children's difficulties can be ascribed to memory overload while RCs are processed as noun modifier sentences. These results contradict the view that there are developmental differences with regard to the way sentences with RCs are parsed and that processing load induces errors particularly manifested in right-branching subject focus sentences. Developmental changes taking place between the ages of 3 and 6 are considered and questions are raised concerning development from the age of 5.The research reported here was carried out while the author read for the PhD degree at the University of London. The writing up of this paper was financially supported by a postdoctoral grant from the Brazilian Research Council (CNPq: 302103-86.4). 相似文献
53.
Angular induction is the process by which one line segment can bias judgment of orientation and/or collinearity of another segment, and it has been established that the magnitude of error is a determinate function of the relative angle between the two. We examined how these known relationships are affected by decomposing the induction segment into an array of scattered points. The bias that was produced by such arrays was found to be consistent with a formal model of angular induction, with the strength of the effect decreasing as the scatter among the points was increased. This decline in strength was almost linear with a logarithmic transform of the dimensions of the stimulus array. We also evaluated the hypothesis that the induction stimulus is detected by one or more channels—for example, neurons—for which the sensitivity profiles are modeled as Gabor wavelets. The change in induction strength with increasing point scatter was not predicted by a single width of channel. However, the combined activity of an ensemble of channels that differed in width did match the perceptual effects if one also stipulated that each channel would respond maximally to a fine-line stimulus. 相似文献
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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. 相似文献
56.
Carlos E. Alchourrón 《Studia Logica》1996,57(1):5-18
The purpose of the paper is to present a logical framework that allow to formalize a kind of prima facie duties, defeasible conditional duties, indefeasible conditional duties and actual (indefeasible) duties, as well as to show their logical interconnections. 相似文献
57.
Maureen W. Lovett Susan L. Borden Patricia M. Warren-Chaplin Léa Lacerenza Teresa DeLuca Rosa Giovinazzo 《Brain and language》1996,54(3):447-480
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. 相似文献
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