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741.
Epitaxial BaTiO3 thin films grown on MgO-buffered R-plane-cut Al2O3 substrates show a non-uniform distribution of planar defects. Transmission electron microscopy allows the determination of the distributions of planar defects with respect to the Al2O3 substrate. The BaTiO3 film, the MgO buffer and the Al2O3 substrate have an orientation relationship of [100]BaTiO3//[100]MgO//[1120]Al2O3, (010)BaTiO3//(010)MgO//(1104)Al2O3 and (001)BaTiO3//(001)MgO// ≈ (1102)Al2O3 (about 5°; deviation). Under the above relationship, most of the {111} stacking faults occur on (111) and (111) planes, that is two of four sets of {111}BaTiO3, whereas cracks in the BaTiO3 film (and MgO buffer) are situated on the (100) planes. The anisotropic distribution of planar defects is regarded as a consequence of an anisotropic stress in the films generated during their fabrication. 相似文献
742.
Xiuyan Guo Shan Jiang Hongyi Wang Lei Zhu Jinghua Tang Zoltan Dienes Zhiliang Yang 《Consciousness and cognition》2013,22(1):203-211
We demonstrated unconscious learning of task-irrelevant perceptual regularities in a Serial Reaction Time (SRT) task in both visual and auditory domains. Participants were required to respond to different letters (‘F’ or ‘J’, experiment 1) or syllables (‘can’ or ‘you’, experiment 2) which occurred in random order. Unbeknownst to participants, the color (red, green, blue or yellow) of the two letters or the tone (1–4) of the syllables varied according to certain rules. Reaction times indicated that people indeed learnt both the color and tonal regularities indicating that task-irrelevant sequence structure can be learned perceptually. In a subsequent prediction test of knowledge of the color or tonal cues using subjective measures, we showed that people could acquire task irrelevant knowledge unconsciously. 相似文献
743.
快速而准确地检测威胁性信息是进化过程中形成的一种重要能力,是有效应对危险的前提条件,对有机体的生存具有重要价值.威胁性信息的检测由不同的神经通路合作完成.在视觉通道中,皮层通路的精确检测和皮层下通路的快速检测在杏仁核得到整合.杏仁核能接受多感觉通道的信息输入,并接受额叶的调节,是威胁性信息加工中连通自上而下加工和自下而上加工的枢纽.将来的研究需要进一步关注杏仁核的功能以及不同的神经通路如何合作完成威胁性信息的检测. 相似文献
744.
745.
The authors explored the phenomenon of unintentional changes in the equilibrium state of a multijoint effector produced by transient changes in the external force. The subjects performed a position-holding task against a constant force produced by a robot and were instructed not to intervene voluntarily with movements produced by changes in the robot force. The robot produced a smooth force increase leading to a hand movement, followed by a dwell time. Then, the force dropped to its initial value leading to hand movement toward the initial position, but the hand stopped short of the initial position. The undershoot magnitude increased linearly with the peak hand displacement and exponentially with dwell time (time constant of about 1 s). For long dwell times, the hand stopped at about half the total distance to the initial position. The authors interpret the results as consequences of a drift of the referent hand coordinate. Our results provide support for back-coupling between the referent and actual body configurations during multijoint actions and produce the first quantitative analysis of this phenomenon. This mechanism can also explain the phenomena of slacking and force drop after turning visual feedback off during accurate force production task. 相似文献
746.
Junlong Luo Xin Liu Edward J. N. Stupple Entao Zhang Xiao Xiao Lei Jia Qun Yang Haijiang Li Qinglin Zhang 《International journal of psychology》2013,48(3):224-231
Belief bias is the tendency to accept conclusions that are compatible with existing beliefs more frequently than those that contradict beliefs. It is one of the most replicated behavioral findings in the reasoning literature. Recently, neuroimaging studies using functional magnetic resonance imaging (fMRI) and event‐related potentials (ERPs) have provided a new perspective and have demonstrated neural correlates of belief bias that have been viewed as supportive of dual‐process theories of belief bias. However, fMRI studies have tended to focus on conclusion processing, while ERPs studies have been concerned with the processing of premises. In the present research, the electrophysiological correlates of cognitive control were studied among 12 subjects using high‐density ERPs. The analysis was focused on the conclusion presentation phase and was limited to normatively sanctioned responses to valid–believable and valid–unbelievable problems. Results showed that when participants gave normatively sanctioned responses to problems where belief and logic conflicted, a more positive ERP deflection was elicited than for normatively sanctioned responses to nonconflict problems. This was observed from ?400 to ?200 ms prior to the correct response being given. The positive component is argued to be analogous to the late positive component (LPC) involved in cognitive control processes. This is consistent with the inhibition of empirically anomalous information when conclusions are unbelievable. These data are important in elucidating the neural correlates of belief bias by providing evidence for electrophysiological correlates of conflict resolution during conclusion processing. Moreover, they are supportive of dual‐process theories of belief bias that propose conflict detection and resolution processes as central to the explanation of belief bias. 相似文献
747.
The negative impacts of excessive and problematic video game playing on both children and adults are attracting increasing concern. Based on self‐determination theory (SDT; Ryan & Deci, 2000), this study hypothesized that the three basic psychological needs of autonomy, competence, and relatedness are positively associated with purpose in life, which in turn acts as a protective factor against problem video game playing among Chinese young adult players. Through a questionnaire survey with a sample of 165 Chinese adults aged between 18 and 30 years (mean age = 22.7 years), we found that perceived autonomy, competence, relatedness, and purpose in life were all negatively correlated with problem game playing. The demographic and psychological factors explained 38% of the variances of problem game playing. Specifically, gender, perceived relatedness, and purpose in life emerged as the three most salient predictors of problem game playing among the Chinese young adults. The mediating role of purpose in life was evidenced and it was found that purpose in life mediated the influences of the psychological needs proposed by SDT on problem game playing. Moreover, young men were significantly more susceptible to problem game playing than their female counterparts. To conclude, psychological needs and purpose in life influenced Chinese young adults’ vulnerability to problem game playing directly or indirectly. Intervention programs that encourage social involvement and voluntary work, as well as counseling service that helps clients to search for life purpose, are suggested for intervening in problem game playing among Chinese young adults. 相似文献
748.
749.
Wen-jun Gui Peng-yun Wang Xu Lei Tian Lin Marilyn Horta Xiao-yi Liu 《Memory (Hove, England)》2013,21(3):387-396
ABSTRACTEvidence has demonstrated that sleep-related memory consolidation declines in ageing. However, little is known about age-related changes to sleep-related emotional memory consolidation, especially when considering the positivity effect observed in older adults. In the present study, we sought to explore whether there is a positive emotional bias in sleep-related memory consolidation among healthy older adults. Young and older adults were randomly assigned either into a sleep or wake condition. All participants encoded positive, negative, and neutral stimuli and underwent recognition tests immediately (test 1), after a 12-hour sleep/wake interval (test 2), and 3 days after test 2 (test 3). Results showed that age-related differences of sleep beneficial effect were modulated by emotion valence. In particular, sleep selectively enhanced positive memory in older adults, while in young adults sleep beneficial effect was manifested in neutral memory. Moreover, the sleep beneficial effect can be maintained at least 3 days in both young and older adults. These findings suggest that older adults had preserved but positive bias of sleep-related memory consolidation, which could be one of the underlying mechanisms for their generally better emotional well-being in daily life. These findings highlight the dynamic interplay among sleep and emotional memory in older adults. 相似文献
750.
本研究以高兴、愤怒和中性面孔图片为实验材料,采用空间线索任务,借助事件相关电位技术(ERP)探讨低自尊个体注意偏向的内在机制及生理基础,即从电生理的角度,探讨注意偏向的内在机制是反映了注意的快速定向还是注意的解脱困难,亦或是既有快速注意定向又伴随注意的解脱困难。行为数据发现,高低自尊个体在有效提示下的反应显著快于无效提示条件。脑电数据发现,无效提示条件下,愤怒面孔后的靶子比高兴和中性面孔后的靶子在低自尊个体中诱发了更大的P1和更小的N1波幅,有效提示下无显著差异;高自尊个体在N1和P1波幅上无显著结果。晚期P300成分上,无效提示比有效提示诱发了更正的波幅,未发现自尊相关的显著差异。结果表明,低自尊个体对评价性威胁信息(愤怒)的注意偏向是对威胁信息(愤怒)的注意解脱困难。 相似文献