口腔修复体制作技术发展的辩证思考

口腔修复体制作技术发展经历了从手工操作到计算机辅助制作、从"去材成形"到"增材制造"、从间接制造到直接制造发展阶段.回顾和分析口腔修复学技术发展中存在的基本矛盾以及矛盾对立统一运动的基本规律,有助于口腔医生自觉地培养和建立自然辩证观念,提高辩证思维能力,更好地把握口腔修复学发展趋势和规律.     

The ameliorating effect of oroxylin A on scopolamine-induced memory impairment in mice

Oroxylin A is a flavonoid and was originally isolated from the root of Scutellaria baicalensis Georgi., one of the most important medicinal herbs in traditional Chinese medicine. The aim of this study was to investigate the ameliorating effects of oroxylin A on memory impairment using the passive avoidance test, the Y-maze test, and the Morris water maze test in mice. Drug-induced amnesia was induced by administering scopolamine (1 mg/kg, i.p.) or diazepam (1 mg/kg, i.p.). Oroxylin A (5 mg/kg) significantly reversed cognitive impairments in mice by passive avoidance and the Y-maze testing (P<.05). Oroxylin A also improved escape latencies in training trials and increased swimming times and distances within the target zone of the Morris water maze (P<.05). Moreover, the ameliorating effects of oroxylin A were antagonized by both muscimol and diazepam (0.25 mg/kg, i.p., respectively), which are GABA(A) receptor agonists. Furthermore, oroxylin A (100 microM) was found to inhibit GABA-induced inward Cl(-) current in a single cortical neuron. These results suggest that oroxylin A may be useful for the treatment of cognitive impairments induced by cholinergic dysfunction via the GABAergic nervous system.     

情绪对学习不良青少年选择性注意和持续性注意的影响

以学习不良青少年为被试,采用成绩反馈法诱发情绪,考察了情绪对学习不良青少年选择性注意和持续性注意的影响,结果表明：（1）情绪会影响学习不良青少年的选择性注意,具有积极低唤醒情绪的学习不良青少年,他们的选择性注意的反应时显著短于消极情绪下的被试;(2)学习不良青少年的情绪会影响到他们的持续性注意能力,消极高唤醒的情绪能够增加虚报率,而积极高唤醒的情绪能够提高判断标准,降低虚报率     

区块与事件相关混合设计:一种新的fMRI研究范式

本文在对区块设计和事件相关设计进行简要回顾的基础上,介绍了当前fMRI研究中一种新的研究范式——区块与事件相关混合设计。这种研究范式能够有效地分离认知加工过程中持久的、状态相关的过程与短暂的、项目相关的过程,并且已经在fMRI研究中得到了初步的应用。文章最后指出了使用这种研究范式时需要注意的一些问题,并且指出了其在认知科学研究中的应用前景。     

Agreement in personality judgments within and between nonoverlapping social groups in collectivist cultures

The social context hypothesis states that people behave differently in different social groups because group norms and context-specific interpersonal relationships uniquely affect behavior. Consequently, a person who is a member of different, nonoverlapping social groups (i. e., the members of different groups are unacquainted) should be judged consensually on personality traits within each group; however, between groups there should be less agreement in judgments. This research focused on cultural moderation of the social context effect in two collective cultures (China and Mexico) with different norms for interpersonal relationships. Among Chinese, there was greater consensus in trait judgments within groups than between groups, whereas in Mexico, agreement within and between groups was equivalent. Culturally based relationship norms that affect cross-context consistency of behavior and, in turn, the consistency of trait judgments across groups were described.     

Effects of mothers' perceptions of children's competence: the moderating role of mothers' theories of competence

There is much evidence that parents' perceptions of children's competence affect the development of children's academic functioning. In the current research, the possibility that this is moderated by parents' theories about the stability of competence was examined. In a 2-wave, 1-year study of 126 children (9 to 12 years old) and their mothers, children's academic functioning (i.e., grades, perceptions of competence, attributions for performance, and mastery orientation) and affective functioning (i.e., self-esteem and depressive symptoms) were examined. Among mothers with relatively high entity theories, their perceptions acted as self-fulfilling prophecies foreshadowing children's academic and affective functioning over time. However, among mothers with relatively low entity theories, mothers' perceptions did not predict children's academic and affective functioning.     

Category and stereotype activation revisited

In Study 1 (N= 230), we found that the participants' explicit prejudice was not related to their knowledge of cultural stereotypes of immigrants in Sweden, and that they associated the social category immigrants with the same national/ethnic categories. In Study 2 (N= 88), employing the category and stereotype words obtained in Study 1 as primes, we examined whether participants with varying degrees of explicit prejudice differed in their automatic stereotyping and implicit prejudice when primed with category or stereotypical words. In accord with our hypothesis, and contrary to previous findings, the results showed that people's explicit prejudice did not affect their automatic stereotyping and implicit prejudice, neither in the category nor stereotype priming condition. Study 3 (N= 62), employing category priming using facial photographs of Swedes and immigrants as primes, showed that participants' implicit prejudice was not moderated by their explicit prejudice. The outcome is discussed in relation to the distinction between category and stereotype priming and in terms of the associative strength between a social category and its related stereotypes.     

Persistence of stereotypic behavior: examining the effects of external reinforcers

Basic research has shown that behavioral persistence is often positively related to rate of reinforcement. This relation, expressed in the metaphor of behavioral momentum, has potentially important implications for clinical application. The current study examined one prediction of the momentum metaphor for automatically reinforced behavior. Participants were 3 children who had been diagnosed with an autism spectrum disorder and who engaged in stereotypic behavior maintained by automatic reinforcement. Results suggested that stereotypic behavior was more resistant to disruption following periods of access to preferred stimuli delivered on a variable-time schedule than following periods without access to preferred stimuli. The implications of these findings for the treatment of automatically reinforced behavior are discussed.     

Forgetting congruent and incongruent stereotypical information

In 2 studies, the authors investigated the directed-forgetting effects of stereotypically congruent, incongruent, and irrelevant information, after the in-group (Swedish) and out-group (immigrant) social categories had been subliminally primed. Because of recent theories of the role of attention and level of processing in the cognitive development of stereotypes, we hypothesized that directed-forgetting effects would be found for stereotype-congruent and irrelevant information but not for stereotype-incongruent information. The results supported our hypothesis, suggesting that the level of processing demanded by the type of information (regardless of whether congruent, incongruent, or irrelevant) may moderate directed-forgetting effects. The authors discussed the social implications of the results.