不同发展阶段的习得性长时程突触增强对新学习的影响

在慢性实验条件下观察到大鼠由学习训练所产生的海马CA_3区习得性长时程突触增强,它的不同发展阶段对新学习任务的习得有不同的作用:(1)在它的形成阶段及巩固阶段对新学习均有易化作用,虽然两个阶段突触效应增强的程度都处于相同的高水平,但后者的易化作用相对要大些,提示这两个发展阶段突触的可塑性变化是有差异的;还有,新学习任务的训练并没有引起突触效应的进一步增强,表明突触效应的长时程增强有“饱和”现象。(2)在它消退后,对新学习任务的习得没有影响。上述结果提示学习的组织形式不同,可从突触机制上影响学习的效果,并进一步证明习得性长时程突触增强是学习和记忆的神经基础。     

判断与决策中的投射偏差

投射偏差是指个体常常会高估未来偏好与当前偏好的一致性, 从而把当前偏好投射到未来的心理倾向性。本文从情感–认知加工、时间修正和心理模拟等视角对投射偏差的心理机制进行了解释, 并概括出投射偏差的内源性(含内脏感觉、情绪状态和需要)和外源性(含事件相关信息、天气状况和选择情境)影响因素, 还总结归纳出投射偏差的三种应对策略, 最后指出了投射偏差在未来研究的方向。     

心理距离对基线比例忽略的影响

基线比例忽略是指在不确定情境中, 个体进行判断和决策时不能充分利用或者忽略基线比例的现象。本研究通过系列情境实验探索了三种不同维度的心理距离, 即时间距离、空间距离和社会距离对基线比例忽略的影响。结果发现, 三种心理距离均能够对基线比例忽略产生影响：当时间距离、空间距离和社会距离较近时, 个体更容易表现出基线比例忽略现象; 而当时间距离、空间距离和社会距离较远时, 个体的基线比例忽略倾向减弱。     

西方文明中的人性假设与现代市场经济的伦理特性

制度伦理与人性假设是密切相关的.性恶论是西方文明中的基本人性假设,早期崇恶制度伦理的起源即是以此为基础的.近代社会契约理论促进了西方市场经济制度伦理的形成,古典和新古典经济学发展了人性假设理论,对市场经济制度伦理至善性进行了探索,到了现代,有限理性主义一定程度上又复归到崇恶制度伦理上.西方人性假设理论折射出的现代市场经济的伦理特性应当是:利己和利他结合、经济和道德一体、竞争与合作的互动、公平与效率的平衡.     

等级反应模型下项目特征曲线等值法在大型考试中的应用

在中国最大的资格考试之一的经济专业资格考试中,为保证不同年度间考试的可比性、进行题库建设和为计算机自适应考试做准备,应用项目反应理论中等级反应模型下的项目特征曲线等值法,采用铆测验等值设计,实现了4个年度考试资料的项目参数和能力参数的等值,并成功地组建了经济专业题库。在此基础上,利用等值技术对不同年份试卷的划界分数进行了比较,为经济考试的合格标准制定、确保考试的公平性提供了实证依据。     

Digging beneath the surface: Results from stage one of a qualitative analysis of factors influencing the well-being of trans youth in Quebec

ABSTRACT

Background: The literature on trans youth has been dominated by etiological studies interested in trans experience as a medical phenomenon. An emerging body of literature has begun to document that trans youth are a diverse, vulnerable, yet resilient population, and to investigate the role of various sites of support such as the family, peer groups, institutions, and community spaces in contributing to or impeding trans youth's well-being.

Method: This article presents the results of Stage One of interviews (n = 24) conducted for a Community-Based Participatory Action Research (CBPAR) qualitative research project based in Quebec. It studies the factors that enhance trans youth's well-being as well as the factors of oppression that negatively affect it. This paper offers a brief overview of the anti-oppressive methodology used for this project, emphasizing how CBPAR was combined with Grounded Theory (GT) methods to encourage the direct involvement of communities and the translation of knowledge into action.

Results: We present preliminary categories emerging through the ongoing axial coding process. These categories address trans youth's experiences in and perceptions of various “sites”: 1) healthcare services both for gender-related and general care, 2) other institutional spaces, 3) the family and other social circles, and 4) community spaces.

Conclusion: While much of this study's results support existing evidence on trans youth's experiences, they also provide a more nuanced portrayal of the complex ways in which recognition, as well as non-, mis-, or mal-recognition, influence trans youth's well-being at different sites. We also argue that recognition itself must be considered through the lens of intersectionality.     

清末民初教科书的现代伦理精神启蒙

教科书不但是知识传播的工具,还是思想启蒙的利器。在强调立国必先立民的时代感召下,富有近代个体意识的个人、人权、人格等内容不断出现在清末民初教科书中。此时的教科书强调独立自主的健全人格的养成、关注自由平等观念的普及、推崇社会公共道德的遵守。但清末民初教科书的现代伦理精神的启蒙,受进化论影响明显,传统伦理的痕迹仍然很重,且浓厚的国家民族色彩压倒了终极的个人关怀。     

Late expression of brain-derived neurotrophic factor in the amygdala is required for persistence of fear memory

In many instances, increase in neuronal activity can induce biphasic secretion of a modulator. The initial release of the modulator triggers the induction of synaptic plasticity, whereas the second-phase release reinforces the efficacy of synaptic transmission and growth of dendrites and axons. In this study, we showed that fear conditioning not only induced the first but also a second peak of brain-derived neurotrophic factor (BDNF) expression. Fluorescent immunohistostaining confirmed that BDNF expression increased at 1 and 12 h after conditioning and returned to baseline at 30 h after conditioning. Mature BDNF expression increased in a similar manner. TrkB-IgG or K252a infusion before training impaired fear memory on days 1 and 7 after training. In contrast, TrkB-IgG or K252a infusion 9 h after fear conditioning did not affect memory retention on day 1 after training but impaired fear memory on day 7 after training. Fear conditioning significantly enhanced Zif268 expression in the amygdala at 12 h after training; this enhanced expression was completely inhibited by TrkB-IgG infusion 9 h after training. The level of growth-associated protein 43 (GAP-43), a marker of newly formed synapses, in the amygdala increased 7 days after fear conditioning. Moreover, conditioned rats had higher AMPA/NMDA ratio than unpaired rats. These results suggest that consolidated memory could be continuously modulated by previous molecular changes produced during memory acquisition.     

同一学习中海马不同区的习得性长时程突触增强的形成

本研究探查大鼠分辨学习中海马齿状回(DG)和CA_3区突触效应的变化及其相互关系,以探讨同一学习中海马不同区突触可塑性变化的特点及其相互关系,进一步论证习得性长时程增强(LTP)是学习和记忆的神经基础。发现:(1)穿通纤维的单个刺激可在DG和CA_3同时记录到潜伏期、峰值和波形各异的群体峰电位(PS);在一定范围内PS随刺激强度的增加而增大,但DG的PS增大程度比CA_3的小;据此,检测刺激的强度应选在该范围内。(2)随着行为训练,DG和CA_3区的突触传递同时产生LTP,两者LTP的发展是显著正相关关系(P<0.01),PS峰值同时达到最高水平,且先于分辨反应达学会标准,首次表明在同一学习中大鼠海马的DG和CA_3的习得性LTP是同时产生的。本研究还表明,在慢性实验下同时记录和分析行为学习中海马两个区突触效应的变化及其相互关系是可能的,这给从神经环路角度研究学习和记忆的突触机制提供了有用的模型。     

海马齿状回突触效应的习得性长时程增强

本实验应用慢性埋植电极技术以电生理学给合行为学的方法,观察大白鼠海马齿状回在以视觉和味觉信号为条件信号的条件反应的建立、巩固和消退过程中突触效应的变化。结果表明在明暗辨别学习中出现突触效应长时程增强(LTD),其保持时间的长短与巩固性训练的多少呈正相关,LTP消退,习得行为也消退。对照实验证明它并非测试本身所引起,提示此习得性LTP与学习和记忆活动是密切相关的。但在建立条件性味觉厌恶中,却无LTP出现。这就从突触水平上进一步证明我们提出的海马在不同感觉信息的记忆活动中其作用是不同的及海马不仅在记忆的形成,而且在其保持和再现中也有重要作用的观点。