基于工作记忆内容的注意:儿童与成人的比较研究

选取10名小学儿童(7~8岁)和10名大学生(19~27岁)作为被试,采用"工作记忆+视觉搜索"的双任务实验范式,探讨儿童与成人基于工作记忆内容的视觉注意的异同.实验要求被试在工作记忆保持阶段完成一个视觉搜索任务,结果发现儿童与成人均表现出基于工作记忆内容的注意:相对于中性条件来说,工作记忆内容与干扰项匹配会显著降低成人被试的搜索绩效,而工作记忆内容与目标匹配会显著提高儿童被试的搜索绩效.研究结果表明,尽管儿童和成人都表现出了基于工作记忆内容的视觉注意,但儿童较成人能更好地运用该注意机制以提高视觉搜索绩效且受其不利影响较少.     

自闭症儿童工作记忆研究综述

工作记忆是一个涉及材料在线保持的系统．对自闭症的认知基础进行解释的执行模型激发了大量的自闭症儿童工作记忆的研究．多数研究支持了自闭症儿童工作记忆的言语广度正常的结论．自闭症儿童视觉空间工作记忆的研究没有得到一致的结论,但越来越多的证据显示了自闭症儿童的视觉空间工作记忆的异常．自闭症儿童工作记忆的中央执行成份仅显示了局部的受损．虽然自闭症儿童操作任务的结果揭示了损伤的存在,但没有得到其他研究的证实．当使用反眼动任务和不相容任务时,及go／no—go范式中存在与反应抑制关联的刺激转换时,白闭症儿童的工作记忆受损．今后的研究应以整体的、发展的视角,不断改进工作记忆的研究方法,在选取适当匹配组儿童的前提下,对白闭症儿童进行分类研究．     

工作记忆、注意与一般液态智力之间关系的实证研究

选取高中生、大学生、研究生和高中青年教师共48名.采用被试内设计,对工作记忆、注意与智力之间的关系进行了研究.结果表明:①三者之间的关系与所选用的测试材料有关.用汉语双字词所测的工作记忆与智力之间的相关不显著,而用大写字母所测的工作记忆与智力之间相关显著.②三者之间的关系与其所应用的注意评定测验有关.工作记忆与选择注意相关显著,而与维持注意相关不显著;智力与维持注意相关显著,而与选择注意相关不显著.     

工作记忆训练改善学习困难儿童症状的有效性：行为和ERP证据

采用自适应活动记忆任务，对学习困难儿童进行20 d的计算机化工作记忆训练.对训练前后进行认知和脑电测查发现，训练组在以数字倒背和n-back任务所代表的工作记忆上具有近迁移效应，在以瑞文测试所代表的流体智力上有远迁移效应并具有长期维持效应.同时，训练组在顶区的P300波幅和LNC波幅显著增大.结果表明，工作记忆训练可增强大脑的信息更新和维持能力，提高学习困难儿童的工作记忆广度和流体智力，长期效应可改善学业成绩，是一种对学习困难儿童有效的认知干预手段.     

不同年级学生的工作记忆研究

从小学三年级、五年级、初中二年级、高中二年级中分别挑选被试对象各80人，进行工作记忆广度测量。结果发现：1．工作记忆广度的发展随着年级的增长而发展；2．各年级学生的两项工作记忆广度测试成绩与语文、数学成绩有较高的正相关。结论：工作记忆与学生的学业成绩关系密切，即工作记忆是有效学习的前提。     

抑郁症患者工作记忆与血清微量元素相关性

目的:探索抑郁症患者工作记忆损害及其与血清微量元素的关系.方法:采用数字广度、数字2-back、视觉再生及数字-符号转换测试方法,评估30例符合美国精神障碍统计与诊断手册第4版(DSM-IV)诊断标准的抑郁症患者(患者组)和30例健康志愿者(对照组)的工作记忆,同时,检测两组研究对象的血清钙、磷、镁、铜、锌和铁六种微量元素与工作记忆之间的相关性.结果:抑郁症患者数字广度(顺背、倒背、总分)、数字2-back(正确率、反应时)和数字-符号测试成绩显著低于正常对照组(P0.05),差异有统计学意义;抑郁症组血清中铜含量明显高于对照组,差异具有显著性(P0.05);数字2-back任务正确率和视觉再生测验得分与镁离子含量呈正相关;数字-符号测验得分与铜离子含量呈正相关;视觉再生测验得分与锌离子含量呈负相关.其他工作记忆测试成绩与离子无相关.结论:抑郁症患者确实存在工作记忆的缺陷,主要体现在工作记忆容量变小,言语工作记忆及中央执行系统功能受损;且抑郁症工作记忆损害可能与血清微量元素锌、铜、镁离子浓度密切相关.     

《大脑与认知》2004年—2007年工作记忆研究终述

对工作记忆的广度和容量的研究很多,本文阐述了几个观点：工作记忆中客体的呈现受过去经历的影响;情感的决定受工作记忆条件影响,高工作记忆条件下产生了一种＂目光短浅＂的决定风格;在时间判断任务中由于工作记忆过程的不同会产生的与年龄相关的差异。     

工作记忆与阅读的关系研究

工作记忆在阅读理解中具有重要作用。工作记忆由于其具有存储和计算功能,在理解能力方面是很复杂的。课文理解需要占用很大部分的工作记忆资源。在阅读的解码和加工过程中,语篇的重要思想或当前命题必须保存在记忆中。同时,能在理解过程中提取这些思想或命题。     

工作记忆理论模型演变及其应用

工作记忆是一种对信息进行暂时加工和贮存的能量有限的记忆系统。本文在分析工作记忆理论模型演变过程的基础上,探讨工作记忆对阅读理解,写作,数学问题解决等复杂认知活动中的作用,从而深入挖掘工作记忆研究的实际应用价值。     

基于工作记忆内容的注意导向的影响因素

工作记忆内容对视觉搜索中注意选择的影响到底如何,与工作记忆内容匹配的项目是否总是会自动捕获注意,至今仍存在争议。本研究针对前人研究中存在的差异和不足,统一采用"记忆-搜索"双任务范式来探讨搜索任务难度、搜索项目刺激强度以及记忆任务呈现时间对基于工作记忆内容的注意导向的影响。结果发现:当采用困难搜索任务时,干扰条件下被试反应时与中性条件下反应时无显著差异,说明难度会影响工作记忆内容对注意选择的自动导向效应,但这种影响只有在搜索任务难度足够大的情况下才能体现出来。而在本研究中并未发现刺激强度和记忆任务呈现时间这两个因素对基于工作记忆内容的注意导向的影响,即无论刺激强度高低,或记忆任务呈现时间长或短,与工作记忆内容匹配的搜索项目还是会"自动捕获注意",导致干扰条件下被试反应时显著慢于中性条件。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the