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In some recent papers, the authors and Peter Gärdenfors have defined and studied two different kinds of formal operation, conceived as possible representations of the intuitive process of contracting a theory to eliminate a proposition. These are partial meet contraction (including as limiting cases full meet contraction and maxichoice contraction) and safe contraction. It is known, via the representation theorem for the former, that every safe contraction operation over a theory is a partial meet contraction over that theory. The purpose of the present paper is to study the relationship more finely, by seeking an explicit map between the component orderings involved in each of the two kinds of contraction. It is shown that at least in the finite case a suitable map exists, with the consequence that the relational, transitively relational, and antisymmetrically relational partial meet contraction functions form identifiable subclasses of the safe contraction functions, over any theory finite modulo logical equivalence. In the process of constructing the map, as the composition of four simple transformations, mediating notions of bottom and top contraction are introduced. The study of the infinite case remains open.  相似文献   
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The time course of lexical access in fluent Portuguese-English bilinguals and in English speaking monolinguals was examined during the on-line processing of spoken sentences using the phoneme-triggered lexical decision task (Blank, 1980). The bilinguals were tested in two distinct speech modes: a monolingual, English or Portuguese, speech mode, and a bilingual, code-switching, speech mode. Although the bilingual’s lexical decision response times to word targets in the monolingual speech modes were identical to those of the monolingual subjects, their response times to code-switched word targets in the bilingual mode were significantly slower. In addition, the bilinguals took longer to detect nonwords in both the monolingual and bilingual modes. These results confirm that bilinguals cannot totally deactivate their other language when in a monolingual speech mode. It is hypothesized that bilinguals search both lexicons when confronted with nonwords, even when in a totally monolingual mode, and that they search the base-language lexicon before the other lexicon when in a bilingual, code-switching, speech mode.  相似文献   
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This article seeks to identify the theoretical tools that supported Michel de Certeau's political discernment during the crisis of May 1968 in France. De Certeau's ability to elucidate the novelty and complexity of this event is linked to the intertwining of his experiences as a historian, traveller (voyageur), and Christian (specifically a Jesuit). De Certeau's articulation of a 'theology of difference' allowed him to construct the intellectual and spiritual tools that enabled a lucid discernment of May 1968. Through this theology, derived from negative theology, de Certeau made the experience of faith operative at a moment of cultural crisis. The article also analyses possibilities involved in the ‘rupture’, that is, the fracture that is implied in modernity; in the notion of an event that highlights the deficiency of language, its incapacity to establish ‘a truthful communication’ in society; and the recognition of the poetic dimension of speech, which is capable of interweaving speech and action. The May 1968 event invites these elements mutually to redefine themselves.  相似文献   
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Critical action—behaviours aimed at dismantling systems of oppression—must be examined within youths' racialized experiences and should incorporate cultural and sociohistorical factors. We considered an expansive list of items capturing youth behaviours to create a novel four-factor (service, community change, expression, and care) measure of critical action for Asian and Hispanic/Latinx youth. Multiple distinct profiles of critical action were identified within both racial-ethnic groups, and associations between the profiles and sociodemographic and contextual support variables were explored. Gender differences in the type of critical action were found in both racial-ethnic groups, pointing to the potential influence of gender roles on critical action among these populations. Differences in critical action patterns were also found between those born in the U.S. versus those born outside the U.S.; access to critical action may differ within racial-ethnic groups depending on birthplace and associated nuances in familial and cultural contexts. This paper demonstrated a need for attending to variation between and within groups in the study of critical action in order to effectively support racialized youth's coping within and resistance against systems of oppression.  相似文献   
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自闭症谱系障碍(Autism Spectrum Disorder, ASD)表现为社会交往困难以及重复刻板兴趣或行为。社交动机理论提出ASD个体是由于社交动机缺乏导致的社交障碍。目前该理论缺乏理论元素及结构关系的系统论证, 及基于此理论的低龄ASD儿童群体的研究证据。本研究拟采用心理实验法、眼动及近红外脑成像技术, 探索低龄ASD儿童早期社交奖赏、社交定向异常眼动标记及眶额叶脑区活动的神经机制。此外, 通过音乐奖赏强化学习的干预方式改善该理论的核心元素(社交奖赏), 观测能否改善ASD儿童的社交动机。本研究的开展有望对该理论进行系统验证, 并形成改善社交行为的潜在干预方案。  相似文献   
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Summary This paper expands a new hypothesis on the causal mechanisms underlying irrelevant behaviour. It begins with a critical summary of earlier theories which attempted to explain displacement activities, but failed to predict the consistency with which certain types of behaviour are shown in stressful situations by a variety of species. Behavioural and physiological studies suggest that these behaviour patterns are closely associated with the incipient activation of sleep. The functional significance of this link and some of the causal processes which may be responsible for it are discussed. Paradoxically, however, displacement activities occur when animals are in a state of high arousal. The concept of arousal is reconsidered in the light of information theory and assumed to be closely correlated with the information processing rate in the nervous system. The relationships between neural and autonomic arousal are considered in this context. It is argued that over-arousal may occur when information handling exceeds the limited channel capacity of the system, with a consequent loss of efficiency. It is pointed out that there are mechanisms capable of controlling the information influx into the brain, and it is hypothesized that they are tied up in a feedback mechanism which regulates arousal and which involves the activation of a de-arousal system, corresponding to the neurological sleep mechanism. Displacement activities are viewed as consequences of this regulatory activation of the sleep system. This hypothesis is then compared with existing theories of displacement and its relationship with them is discussed.
Zusammenfassung Die Arbeit erweitert eine neue Hypothese über die kausalen Mechanismen, die dem übersprungverhalten zugrunde liegen. Sie beginnt mit einer kritischen Übersicht der früher vorgeschlagenen Theorien und zeigt auf, daß diese nicht die Beständigkeit, mit der gewisse Verhaltensweisen von einer Anzahl von Tierarten in Stress-Situationen gezeigt werden, erklären. Verhaltens- und physiologische Studien deuten an, daß diese Verhaltensweisen in einem engen Zusammenhang mit einer partiellen Schlafaktivierung stehen. Die funktionelle Bedeutung dieses Zusammenhanges und die möglichen physiologischen Mechanismen, die dafür verantwortlich sein könnten, werden diskutiert. Paradoxerweise werden aber Übersprungsverhalten dann gezeigt, wenn sich Tiere in einem gesteigerten Wachzustand befinden. In diesem Zusammenhang wird das Arousal-Konzept im Lichte der Informationstheorie neu beleuchtet und es wird angenommen, daß der Arousal-Zustand eines Tieres im engen Zusammenhang mit der jeweiligen Informationsverarbeitungsrate im Nervensystem steht. Die Verhältnisse zwischen neuralem und autonomischen Arousal werden diskutiert. Es wird vorgeschlagen, daß sich Überarousal dann einstellt, wenn die Informationsverarbeitungsrate die Kanalkapazität des Systems übersteigt mit einem sich daraus ergebenen Wirkungsgradverlust. Es wird darauf hingewiesen, daß es Mechanismen gibt, die den Informationsfluß in das Gehirn regeln und angenommen, daß diese innerhalb eines Rückkopplungssystems funktionieren, welches Arousal reguliert. Diese Regelung benötigt die Aktivierung eines Arousal herabsetzenden Systems, das in den neurologischen Schlafmechanismen besteht. Das Auftreten von Übersprungsverhalten wird als eine Konsequenz dieser regulatorischen Aktivierung des Schlafsystems angesehen. Die Hypothese wird dann mit den vorhandenen Übersprungsverhaltenstheorien verglichen.


The research underlying this paper has been supported by grants from the U.S. Air Force Office of Scientific Research through the European Office of Aerospace Research, the Science Research Council and the Royal Society to Professor N. Tinbergen, F. R. S. and myself. It was partly carried out at the Department of Zoology, Oxford. I am grateful to Dr. S. A. Hillyard who by revising an earlier version contributed much to whatever merits this paper has.  相似文献   
28.
This paper describes a possible near-death experience (NDE) among the Mapuche people of Chile. The individual reporting the experience was in a cataleptic-like state for two days, the experience itself occurring at the end of this period. Some common features of NDEs, such as encounters with deceased people and being sent back, are present, together with clear evidence that past and present cultural environment shape in part the content of mental experiences.This work was funded in part by the University of Chile (DTI Project Q-3064).The author thanks Editorial Andrés Bello for permissionto translate the near death account into English.  相似文献   
29.
The present research focused on power processes in a simulated organizational structure consisting of three hierarchical levels occupied by different numbers of mules and females. Subjects were presented with a chart showing the organizational hierarchy of which they were a member placed at the lowest level, and asked to nominate any person for the leader position vacated by the current incumbent. The results of Experiment I (n = 88 Dutch male and female university students) showed that male subjects strongly overnominated themselves, whereas a majority of the female subjects nominated either self or another female. Of the others that were nominated by both males and females, almost all were occupants of positions immediately below the leader position, indicating the normative influence of a bureaucratic rule of leader succession. Experiment 2 was a replicational study carried out in a different culture (n = lOl Polish male and female university students). Polish subjects adhered to the bureaucratic rule more strongly than their Dutch counterparts, and both females and males nominated mostly males. Results are discussed with reference to gender self-stereotypes and cultural differences.  相似文献   
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