Flicker-light induced visual phenomena: frequency dependence and specificity of whole percepts and percept features

Flickering light induces visual hallucinations in human observers. Despite a long history of the phenomenon, little is known about the dependence of flicker-induced subjective impressions on the flicker frequency. We investigate this question using Ganzfeld stimulation and an experimental paradigm combining a continuous frequency scan (1–50 Hz) with a focus on re-occurring, whole percepts. On the single-subject level, we find a high degree of frequency stability of percepts. To generalize across subjects, we apply two rating systems, (1) a set of complex percept classes derived from subjects’ reports and (2) an enumeration of elementary percept features, and determine distributions of occurrences over flicker frequency. We observe a stronger frequency specificity for complex percept classes than elementary percept features. Comparing the similarity relations among percept categories to those among frequency profiles, we observe that though percepts are preferentially induced by particular frequencies, the frequency does not unambiguously determine the experienced percept.     

An analytic tableau calculus for a temporalised belief logic

A tableau is a refutation-based decision procedure for a related logic, and is among the most popular proof procedures for modal logics. In this paper, we present a labelled tableau calculus for a temporalised belief logic called TML⁺, which is obtained by adding a linear-time temporal logic onto a belief logic by the temporalisation method of Finger and Gabbay. We first establish the soundness and the completeness of the labelled tableau calculus based on the soundness and completeness results of its constituent logics. We then sketch a resolution-type proof procedure that complements the tableau calculus and also propose a model checking algorithm for TML⁺ based on the recent results for model checking procedures for temporalised logics. TML⁺ is suitable for formalising trust and agent beliefs and reasoning about their evolution for agent-based systems. Based on the logic TML⁺, the proposed labelled tableau calculus could be used for analysis, design and verification of agent-based systems operating in dynamic environments.     

非脑死亡患者放弃治疗的原因分析及临床策略

通过对本院2007年～2008年399例放弃治疗后死亡的病历分析,探析放弃治疗的原因,探讨临床对策.病情恶化是放弃治疗的主要原因.放弃治疗涉及医学、哲学、法律等多方面问题.医生应该尽告知义务,尊重患者的生命权、健康权,知情权、选择权和决定权.放弃治疗后,工作的重点应转向安抚和临终关怀,同时规范"放弃治疗"的医学文书.     

如何面对失败的隆胸手术

成功的隆胸手术能够让女性更美丽,但手术失败势必给患者的生理和心理带来巨大的打击.如何正确面对失败的隆胸手术是摆在医患面前的一个严肃的课题.本文详细列举了隆胸手术失败的危害,系统分析了造成隆胸手术失败的原因,积极思索了隆胸手术失败时如何有效的补救.     

首、尾语素频率对中级印尼汉语学习者复合词识别的影响

通过词汇判断任务,探讨语素频率对中级印尼汉语学习者复合词识别的影响。研究结果发现,语素频率影响中级印尼汉语学习者复合词的识别。同时,语素频率对词汇识别的影响受到语素位置的调节。当语素为复合词的首语素时,语素频率高,词汇判断的正确率高;语素频率低,词汇判断的正确率低。当语素为复合词的尾语素时,语素频率对词汇判断正确率的影响受到首语素频率的限制。只有当首语素的频率高时,尾语素的频率才会影响词汇判断的正确率。当首语素的频率低时,尾语素的频率不影响词汇判断的正确率。研究结果支持中级印尼汉语学习者在复合词的表征中产生了语素表征,而且首语素的频率在复合词识别中发挥更重要的作用。     

The leopard cannot change his spots, or can he? Culture and the development of lay theories of change

Chinese and Canadian children were compared to examine cultural and developmental differences in lay theories of change: implicit beliefs about how the world develops and changes over time. Chinese and Canadian children (ages 7, 9, and 11 years) made predictions about future performance, relationships, happiness, and parental incomes based on a series of scenarios. Overall, the Chinese children predicted greater change than did the Canadian children, indicating that they believed more in change than did the Canadians. Moreover, cultural differences increased significantly with age: In comparison with their Canadian counterparts, Chinese children made no more change predictions at age 7, made slightly more change predictions at age 9, and made significantly more change predictions at age 11. This was true for questions starting with an extremely positive or negative state and those starting with a neutral state. Reasons for cultural and developmental differences were discussed.     

基于元认知的认知学习对动态能力影响的实证研究

通过实证研究勾勒出符合动态特征的元认知理论框架,提出构成元认知的6个要素,分别归为元认知策略、元认知调控和元认知知识三个维度.并借助结构方程模型重点分析了元认知、认知学习和动态能力的相关性,以及基于元认知的认知学习对动态能力演化的影响.     

LÉVY HIERARCHY IN WEAK SET THEORIES

We investigate the interactions of formula complexity in weak set theories with the axioms available there. In particular, we show that swapping bounded and unbounded quantification preserves formula complexity in presence of the axiom of foundation weakened to an arbitrary set base, while it does not if the axiom of foundation is further weakened to a proper class base. More attention is being paid to the necessary axioms employed in the positive results, than to the combinatorial strength of the positive results themselves.     

永党元贤《鼓山志》及其文献价值

元贤是清初具有强烈民族意识和气节的禅僧,他的<鼓山志>在清初编纂刊印以后,一直没有广为流通.清修<四库全书>仅有存目,未收全书,国家图书馆等处所收藏的此书均为残本.本文依据的<鼓山志>现藏于世界宗教研究所,为品相极佳的足本,最早被清初藏书家汪宪收藏,乾隆修<四库全书>时呈于朝廷,又辗转藏于八千卷楼、江苏省图书馆,后流传至民间.该书具有重要的版本价值,内中题记、钤印等亦极为珍贵.本文还考察了历代编修的鼓山寺志的内容和存佚情况,对元贤的流传和撰述时间进行了考证,并在标点校勘该书的基础上,与黄任的<鼓山志>的内容加以比较,指出元贤所编的<鼓山志>从内容、特色以及版本上都具有极为重要的文献价值.     

Differential roles for hippocampal areas CA1 and CA3 in the contextual encoding and retrieval of extinguished fear

Recent studies demonstrate that context-specific memory retrieval after extinction requires the hippocampus. However, the contribution of hippocampal subfields to the context-dependent expression of extinction is not known. In the present experiments, we examined the roles of areas CA1 and CA3 of the dorsal hippocampus in the context specificity of extinction. After pairing an auditory conditional stimulus (CS) with an aversive footshock (unconditional stimulus or US), rats received extinction sessions in which the CS was presented without the US. In Experiment 1, pretraining neurotoxic lesions in either CA1 or CA3 eliminated the context dependence of extinguished fear. In Experiment 2, lesions of CA1 or CA3 were made after extinction training. In this case, only CA1 lesions impaired the context dependence of extinction. Collectively, these results reveal that both hippocampal areas CA1 and CA3 contribute to the acquisition of context-dependent extinction, but that only area CA1 is required for contextual memory retrieval.