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971.
In this study the mechanical output (e.g., force, contraction velocity, instantaneous power) about the ankle was measured during a jump with and without occurrence of transportation of power and pre-stretch potentiation. To examine this, a model of the m. triceps surae was used. Eleven subjects performed a maximal one-legged countermovement jump (CMJ) and a maximal one-legged jump with extended knee (EKJ). Ground reaction forces, cinematographic data and electromyograms of m. triceps surae were recorded. The power output, defined as the product of moment and angular velocity, and work done about the ankle were higher during CMJ (1404 W, 130 J) than during EKJ (852 W, 76 J). The peak moments were the same during both jumps. The model of the m. triceps surae showed that the power delivered by m. triceps surae was higher during CMJ than during EKJ, as a result of catapult-action of m. gastrocnemius tendon. The difference in work done is explained, in addition to transportation of energy, by a greater contraction range of m. soleus during CMJ. There is no reason to assume that pre-stretch potentiation plays a role in the difference in mechanical output. The results show that the mechanical output of muscles in complex movements is strongly dependent on the dynamics of the movement, and not only on its contractile capacity. 相似文献
972.
A ROWS is a ROSE: Spelling,sound, and reading 总被引:30,自引:0,他引:30
Guy C. van Orden 《Memory & cognition》1987,15(3):181-198
Skilled readers generally are assumed to make little or no use of words’ phonological features in visual word identification. Contrary to this assumption, college students’ performance in the present reading experiments showed large effects of stimulus word phonology. In Experiments 1 and 2, these subjects produced larger false positive error rates in a semantic categorization task when they responded to stimulus foils that were homophonic to category exemplars (e.g., ROWS for the category A FLOWER) than when they responded to spelling control foils. Additionally, in Experiment 2, this homophony effect was found under brief-exposure pattern-masking conditions, a result consistent with the possibility that phonology is an early source of constraint in word identification. Subjects did, however, correctly reject most homophone foils in Experiments 1 and 2. Experiment 3 investigated the source of this ability. The results of Experiment 3 suggest that subjects detected homophone impostors, such as ROWS, by verifying target foil spellings against their knowledge of the correct spellings of category exemplars, such as ROSE. 相似文献
973.
Social phobia: individual response patterns and the effects of behavioral and cognitive interventions 总被引:1,自引:0,他引:1
P P Mersch P M Emmelkamp S M B?gels J van der Sleen 《Behaviour research and therapy》1989,27(4):421-434
In the present study, the role of individual response patterns in the treatment of social phobic patients was investigated. Seventy-four patients were diagnosed as social phobics. On the basis of extreme scores on a behavioral test (the Simulated Social Interaction Test) and on a cognitive measure (the Rational Behavior Inventory), the response patterns of 39 patients were analyzed, and the patients themselves were classified as either 'behavioral reactors' or 'cognitive reactors'. Half of the patients with each response pattern received a behavioral focused treatment, i.e. social skills training (SST), while the other half received a cognitive oriented treatment, i.e. rational emotive therapy (RET). Patients received group therapy in eight weekly sessions. Within-group differences showed a considerable improvement in all treatment groups. Between-group differences failed to lend support to the hypothesis that treatment that fits a response pattern (i.e. SST for behavioral reactors and RET for cognitive reactors) will result in a greater improvement than one that does not. 相似文献
974.
Psychophysiological and subjective reactions of social phobics and normals to facial stimuli 总被引:2,自引:0,他引:2
H Merckelbach W van Hout M A van den Hout P P Mersch 《Behaviour research and therapy》1989,27(3):289-294
Nine social phobics and 9 normal control subjects were exposed to slides of angry faces, happy faces, and neutral objects (i.e. flowers or mushrooms). Skin conductance responses (SCRs) to the stimuli and eyeblink rate (EBR) during stimulus exposure were recorded. In addition, subjects were asked to rate the stimuli in terms of pleasantness. While angry face stimuli elicited greater SCRs, stronger inhibition of EBR, and were evaluated more negatively than the other stimuli, there were no differences between social phobics and normals in these respects. Thus, the findings lend no support to the idea that social phobics are particularly sensitive to facial cues in general or to negative facial cues in particular. 相似文献
975.
Job seeking, reemployment, and mental health: a randomized field experiment in coping with job loss 总被引:2,自引:0,他引:2
Cognitive theories of adherence to difficult courses of action and findings from previous survey research on coping with a major life event--job loss--were used to generate a preventive intervention, tested by a randomized field experiment. The aim was to prevent poor mental health and loss of motivation to seek reemployment among those who continued to be unemployed and to promote high-quality reemployment. Ss were 928 recently unemployed adults from southeastern Michigan, representing a broad range of demographic characteristics; they were randomly assigned to either the experimental or control condition. The experimental intervention included training in job seeking with a problem-solving process emphasizing inoculation against setbacks and positive social reinforcement. A pretest was administered, followed by posttests 1 and 4 months after the experiment. The experimental condition yielded higher quality reemployment in terms of earnings and job satisfaction, and higher motivation among those who continued to be unemployed. 相似文献
976.
C. A. van Peursen 《Man and World》1989,22(4):471-484
Summary The analysis of philosophically important themes can depart from two different angles. The first one investigates the various answers that have been given to a certain issue, like that of the problem of knowledge, the justification of theories, the notion of culture, etcetera. These answers are often mutually contradictory which, by the way, facilitates their overview (like the schemes of rationalism-empiricism, justification-discovery, universalism-relativism). A second approach starts from the problems (or: problematique) behind the divergent answers (e.g., foundationalism behind both, empiricism and rationalism).In the following sections the issue of discovery is discussed. Here the second line of approach has been followed, not only by making visible a same problematique, but more by trying to set out the common context of the discussion about context of discovery and context of justification. The idea is that this discussion, or better the shift taking place in that discussion, finds its reason in a context in which the distance between traditional methodology and contemporary scientific practice, also between scientific knowledge and the experience of reality has become greater. This is related to the deepening awareness of the cultural context of scientific method. Man and world, scientific method and cultural context are always interacting.From this point of view quite different philosophical approaches show nevertheless similar features pointing to new solutions. A more psychological approach to scientific method (like: Gordon's and Grmek's, even perhaps Gutting's reinterpretation of Popper) and a sociological one (e.g., Barnes, Bloor, and already Durkheim) are opposed to a more logically structured analysis of Nagel, Hempel, and also Popper. Nevertheless the view on the flexibility of scientific method defended along different lines by for instance Achinstein, Bachelard, Hesse, Piaget, Polanyi, Toulmin manifests a certain convergence in those divergent standpoints, the more so since often the cultural context of science is being stressed (e.g., Ladriére, Prigogine, Needham).The miscellany of philosophical orientations, presented in the following sections, can in this way perhaps give profile to deeper tendencies: to relate again scientific method to the context of culture and of human strategy in general. This does not blend, however, the distinction between context of justification and context of discovery. By changing their roles a new overview of this dilemma becomes possible. There is no juxtaposition of both, nor has the one to be absorbed by the other. The conclusion will be that there are still two contexts, but that one is wider, less defined and demarcated from the wider field of daily culture, and that the other is more restricted, functioning as a kind of safetydevice on behalf of the wider strategy of discovery. In such a way discovery is regarded as the wider context of the more restricted context of justification. 相似文献
977.
Johan van Benthem 《Synthese》1982,51(3):431-472
The relation between logic and philosophy of science, often taken for granted, is in fact problematic. Although current fashionable criticisms of the usefulness of logic are usually mistaken, there are indeed difficulties which should be taken seriously — having to do, amongst other things, with different scientific mentalities in the two disciplines (section 1). Nevertheless, logic is, or should be, a vital part of the theory of science. To make this clear, the bulk of this paper is devoted to the key notion of a scientific theory in a logical perspective. First, various formal explications of this notion are reviewed (section 2), then their further logical theory is discussed (section 3). In the absence of grand inspiring programs like those of Klein in mathematics or Hilbert in metamathematics, this preparatory ground-work is the best one can do here. The paper ends on a philosophical note, discussing applicability and merits of the formal approach to the study of science (section 4).I would like to thank David Pearce and Veikko Rantala for their helpful comments. 相似文献
978.
979.
van Rossum JH 《Journal of motor behavior》1980,12(2):145-148
The interpretations of Piaget and Schmidt on the level on which the motor schema is supposedly effective were evaluated in pre-school children of different ages in a throwing task. In an analysis of variance on the accuracy scores, significant main effects for age, sex, and throwing arm were found. Further, the results showed no relationship between accuracy scores with the preferred and non-preferred arm in the younger group, while in the older group a moderate relationship was found. This result was interpreted in terms of structural development and as a warning for studies where Schmidt's variability-of-practice hypothesis is tested. 相似文献
980.
J. F. A. K. van Benthem 《Studia Logica》1980,39(2-3):125-141
In the modal literature various notions of completeness have been studied for normal modal logics. Four of these are defined here, viz. (plain) completeness, first-order completeness, canonicity and possession of the finite model property — and their connections are studied. Up to one important exception, all possible inclusion relations are either proved or disproved. Hopefully, this helps to establish some order in the jungle of concepts concerning modal logics. In the course of the exposition, the interesting properties of first-order definability and preservation under ultrafilter extensions are introduced and studied as well. 相似文献