时间取向与乐观偏差的关系:乐观的中介作用

采用津巴多时间取向量表、生活定向问卷修订版、生活事件量表对870名大学生被试进行调查。结果显示:时间取向与气质性乐观、乐观偏差三者之间存在显著的相关关系;气质性乐观在消极过去取向、宿命现在取向与消极将来事件可能性判断之间呈正向的部分中介作用,在宿命现在取向与积极将来事件可能性判断之间呈负向的部分中介作用,在积极过去取向、未来取向与消极将来事件可能性判断之间呈负向的部分中介作用,在积极过去取向、未来取向与积极将来事件可能性判断之间呈正向的部分中介作用,在消极过去取向与积极将来事件可能性判断之间起完全中介作用。结论:时间取向(除了消极过去取向)直接影响乐观偏差,也可以通过气质性乐观间接影响乐观偏差。     

Neural mechanisms of perceptual learning

The traditional view of cortical visual processing is that primary visual cortex (V1) analyzes simple visual attributes, and that object recognition involves a progressive “complexification” of receptive field (RF) properties along the visual pathway extending into the temporal lobe. Based on our studies with a combination of electrophysiological, imaging, psychophysical and computational approaches, we find to the contrary that V1 is capable of encoding much more complex stimulus features than originally believed, and that it can integrate information over large parts of the visual field. Moreover, V1 is continually involved in encoding information about learned stimulus configurations under top-down influences specific to the trained perceptual task.     

Neural mechanisms of perceptual learning

The traditional view of cortical visual processing is that primary visual cortex (V1) analyzes simple visual attributes, and that object recognition involves a progressive “complexification” of receptive field (RF) properties along the visual pathway extending into the temporal lobe. Based on our studies with a combination of electrophysiological, imaging, psychophysical and computational approaches, we find to the contrary that V1 is capable of encoding much more complex stimulus features than originally believed, and that it can integrate information over large parts of the visual field. Moreover, V1 is continually involved in encoding information about learned stimulus configurations under top-down influences specific to the trained perceptual task.     

触觉信息处理及其脑机制

 触觉不仅包含对物理特征的感知,还包括对情感性信息的识别,其信息的整合是人类认识环境的基础。本文阐述了编码不同特征触觉信息的皮肤感受器是触觉信息感知的结构基础;讨论了触觉信息在外周和中枢神经系统的加工机制。其中脊髓背角是触觉信息在皮层下水平加工的初级枢纽,躯体感觉皮层是加工触觉信息的主要脑区,且针对不同特征的触觉信息加工,存在相对独立的脑网络连接。本文还探讨了触觉与跨模态感觉的交互作用,揭示了多模态感觉信息整合的神经机制及其广泛的应用价值。     

Neural mechanisms of unconscious visual motion priming

The neural correlates of the motion priming were examined in normal young subjects using event-related brain potentials (ERPs) and functional magnetic resonance imaging (fMRI). Visual motion perception can be uncon-sciously biased in favor of a particular direction by a pre-ceding motion in that direction. Motion priming first in-volved an enhancement of ERP amplitude about 100 ms fol-lowing the onset of motion. The amplitudes of ERP compo-nents after 350 ms were also increased. The fMRI results suggest that the early-latency effect reflects modulation of neural responses in extrastriate cortex. Higher-level visual processing areas, including cortical regions MT/MST and the intraparietal cortices were also activated. The findings provide direct evidence that unconscious priming of motion perception is the result of interaction of direction-selective neural responses to motion stimuli. The results cannot be accounted for by refractoriness of neural responses, but in-stead support a theory of motion priming based on motion opponency, as proposed in computational models.     

水杨酸钠诱导耳鸣的神经机制

水杨酸是阿司匹林的主要代谢产物,也是起药理作用的有效成分.高剂量的水杨酸钠可以在动物上可靠地诱导出耳鸣样行为,因此经常被用于研究耳鸣产生的神经机制.因为水杨酸能够在脑脊液中达到较高的浓度,我们设想水杨酸钠通过改变中枢听觉系统的兴奋-抑制平衡而产生耳鸣.为了验证这个假设,我们实验室在过去几年中利用全细胞膜片钳技术研究了水杨酸钠对中枢听觉系统神经元响应和突触传递的影响.我们发现该药物显著地压制GABA神经元的自发活动水平,提示水杨酸钠通过提高中枢听觉系统的兴奋性诱导耳鸣.     

Neural mechanisms of perceptual grouping in human visual cortex

The current work examined neural substrates of perceptual grouping in human visual cortex using event-related potential (ERP) recording. Stimulus arrays consisted of local elements that were either evenly spaced (uniform stimuli) or grouped into columns or rows by proximity or color similarity (grouping stimuli). High-density ERPs were recorded while subjects identified orientations of perceptual groups in stimulus arrays that were presented randomly in one of the four quadrants of the visual field.Both uniform and grouping stimulus arrays elicited an early ERP component (C1), which peaked at about 70ms after stimulus onset and changed its polarity as a function of stimulated elevations. Dipole modeling based on realistichead boundary-element models revealed generators of the C1 component in the calcarine cortex. The C1 was modulated by perceptual grouping of local elements based on proximity, and this grouping effect was stronger in the upper than in the lower visual field. The findings provide ERP evidence for the engagement of human primary visual cortex in the early stage of perceptual grouping.     

网络配流优化准则及其评价研究

针对网络配流问题,分别建立了系统最优、用户均衡和最小化最大延迟3个优化准则下的数学规划模型.在此基础上,给出了评估分配结果的3个指标:平均延迟、最大延迟和公平性,并阐述r其作用与意义.最后给出了一个具体箅例.该算例的结果表明:系统最优分配方法可以保证整体性能最优,但公平性最差,而其他两种方法在某些条件下则可以保证分配方法的公平性,但无法获得较优的整体性能.     

桑叶多糖提取工艺优化研究

设计了三因素三水平正交试验,对桑叶多糖的提取工艺进行了优化研究,确定出桑叶多糖提取的最佳工艺条件为:料液比1∶9,提取时间90min,提取温度90℃,通过实验验证该工艺条件提取桑叶多糖,多糖得率为8.08%,与三因素三水平正交试验所有实验组对照,大于正交试验中9个组合提取率,这些条件的确定为桑叶的大规模开发和应用奠定了基础。     

地形偏压对公路隧道偏压程度影响模型试验研究

为研究地形偏压对公路隧道偏压程度影响,以鹤大高速回头沟隧道为依托工程,采用铁砂、汉白玉等材料,按照几何相似比1∶80,容重相似比1∶1制作隧道模型,结合现场试验验证模型试验的合理性,研究不同埋深、地表坡度对公路隧道偏压程度影响.试验表明:①随着埋深的增大,隧道偏压程度不断减小,当埋深达到35 m以上,偏压程度变化较小,...     

初中生气质性乐观与其情绪调节策略关系研究

采用《生活定向量表》(LOT)和《青少年情绪调节能力调查问卷》对156名初中生气质性乐观、情绪调节策略进行测试,探讨初中生气质性乐观与情绪调节策略之间的相关研究。结果表明:独生子女气质性乐观的乐观维度得分显著高于非独生子女;初中生气质性乐观的乐观维度与其情绪调节策略的情绪知觉、情绪评价、情绪调节自我效能感、应用情绪调节策略、情绪控制和情绪调节反思六个维度呈现出显著正相关;气质性乐观的悲观维度与其情绪调节策略的应用情绪调节策略维度呈正相关,与其情绪调节策略的情绪调节反思维度呈显著正相关。     

这一轮明月,本自无暇--论陈瓘词的明净风格

处于北宋末期的词人陈璀为人正直且淡泊名利，其词于豪放之中透露出一种别样的明净风格。主要表现在四个方面：超脱尘世的旷逸情怀；积极乐观的人生态度；无所羁绊的悠游心灵；自由闲适的生活情境。