Behavioral and neural correlates of memory selection and interference resolution during a digit working memory task

Neuroimaging studies have shown the involvement of prefrontal and posterior parietal cortexes in regulating information processing. We conducted behavioral and fMRI experiments to investigate the relationship between memory selection and proactive interference (PI), using a delayed recognition task with a selection cue presented during the delay indicating which two of the four studied digits were relevant to the present test. PI was indexed by the response time differences between rejecting probes matching and not matching the no longer relevant digits. By varying the delay intervals, we found that the effect of PI did not diminish, even for cases in which the postcue interval was extended to 9 sec, but was stronger when the precue interval was lengthened to 5 sec. By examining the correlation between PI index and neural correlates of memory selection, we found that stronger PI is predicted by lower selection-related activity in the left inferior parietal lobe, the precuneus, and the dorsal middle frontal gyrus. Our results suggest that activity in the prefrontal-parietal network may contribute to one’s ability to focus on the task-relevant information and may proactively reduce PI in working memory.     

Precedence-effect-induced enhancement of prepulse inhibition in socially reared but not isolation-reared rats

Attention to a prepulse presented shortly before a startling stimulus enhances prepulse inhibition (PPI) of startle in normal people, but not in schizophrenics. Fear conditioning for the prepulse enhances PPI in socially reared, but not isolation-reared, rats. In humans, selective attention to acoustic signals against masking can be facilitated by precedence-effect-induced perceived spatial separation between the signal and the masker. This study investigated whether perceived spatial separation between a prepulse and a noise masker enhances PPI in socially reared rats and isolation-reared rats. The results show that both PPI and conditioning-induced PPI enhancement were larger in socially reared rats than in isolation-reared rats. More important, in socially reared, but not isolation-reared, rats, a further PPI enhancement was induced by precedence-effect-induced perceived separation between a prepulse and a masker only after the prepulse became fear conditioned. Thus, perceived separation facilitates normal rats’ attention to a conditioned prepulse and enhances PPI. Isolation rearing impairs rats’ ability to attend to ecologically significant acoustic events.     

5岁儿童能够理解假装的心理表征:对Moe任务的质疑

本研究通过三个实验对Lillard的Moe假装任务进行了重复与改进,旨在探讨儿童对假装行为中知识状态作用的理解,进而讨论儿童对假装的心理本质的理解。实验一表明,“是否”问题使得5岁儿童在该任务上表现出肯定回答倾向;实验二表明．当改变提问方式,在问题中提供选择项目后,5岁儿童在该任务上的通过率有显著提高．肯定回答倾向明显减弱;实验三表明,当减少指导语中相互矛盾的信息、明确指出主人公知道某物而不知道另一物以及减弱对未知状态和知道状态的强调的情况下．5岁儿童能根据主人公所知道的事物来推断出其行为是在假装成该事物,能理解到知识状态在假装行为中的作用。这一结果表明5岁儿童能够理解到假装中所隐含的心理表征,Lillard所提出的Moe任务范式低估了儿童对假装的心理本质的理解能力。     

成功老龄化的SOC模型研究综述

本文简单回顾了关于成功老龄化研究的历史,综合阐释其定义及指标,并引入Baltes经典成功老龄化的SOC模型,详细介绍它的原理及其组成部分——选择、优化和补偿,并概述它对老龄化满意度的积极影响,最后总结了该领域研究中尚存的问题。     

英国哲学研究现状及其简要分析

[作者说明]2007年我受国家留学基金委的资助,到英国进行为期半年的学术访问,走访了英国的几所主要大学哲学系,采访了许多英国著名哲学家,查阅了大量英国哲学最新研究资料,参加了在英国召开的各种国际学术研讨会,对英国哲学的研究现状有了进一步的了解。根据我所了解的情况,我对英国哲学的研究现状做出如下简要分析,供参考。     

RBF神经网络在股价预测中的应用

提出了一种基于RBF神经网络的股票价格预测模型。该模型通过对历史股价数据的分析,采用K-均值聚类算法动态确定RBF网络中心,根据梯度下降法进行自适应权值调整。并且根据股价的差异大,时变性强和高度非线性的特点,对RBF网络的学习算法进行了改进,进一步提高了RBF网络的非线性映射能力和自适应能力,最后运用该模型对股票走势进行了预测。     

分配公正、程序公正、互动公正影响效果的差异

以大学生奖学金评比为例,探讨了组织公正各维度影响效果的差异。以661名大学生为被试,采用2×2×2的完全随机设计,以情境故事法（scenarios）呈现刺激,研究了奖学金评比中分配公正、程序公正、互动公正对大学生学习投入、班级荣誉感、班级归属感、与辅导员的关系的影响。结果表明,组织公正三个维度与效果变量之间存在清晰的对应影响关系：分配公正主要影响具体、以个人为参照的效果变量;程序公正主要影响与组织有关的效果变量;互动公正主要影响与上司有关的效果变量。     

成人学习不良的神经心理与行为遗传研究

介绍了成人学习不良者神经心理与行为遗传方面的研究,深入分析了成人学习不良中阅读不良的电生理和行为遗传特点,并简要总结了有关数学不良的神经心理与行为遗传的相关机制。     

n-back任务下视觉工作记忆负荷研究

实验采用n-back范式,考察了视觉工作记忆负荷与反应时、辨别力和主观评价的关系,以及空间位置记忆负荷与图形记忆负荷的差异。结果发现,随着记忆负荷的增大,反应时延长,辨别力降低,主观负荷提高。视觉图形记忆任务的负荷水平高于视觉空间位置记忆任务的负荷水平;同时也为视觉图形记忆和视觉空间记忆具有不同的加工过程提供了证据。     

催产素、孕激素和雌激素对厌恶的影响及其神经生理机制

厌恶是人和动物最基本的情绪之一,起源于口腔对苦味(有毒)物质的排斥,常伴有恶心呕吐和远离诱发刺激的强烈愿望,具有回避潜在疾病威胁的功能。大量动物和人类研究表明,催产素、孕激素和雌激素不同程度地影响核心厌恶刺激的感知、核心厌恶情绪的产生与表达、条件性厌恶习得和厌恶表情识别。三种激素主要通过作用于五羟色胺、γ-氨基丁酸、乙酰胆碱和谷氨酸等神经递质受体,调节杏仁核、脑岛、前扣带回、壳核、梨状皮层、额中回等脑区活动,影响厌恶加工。未来研究应当在准确测量激素水平和控制实验任务难度的基础上,探究各激素对不同感觉通道厌恶加工的影响,及其性别的调节作用;同时结合脑成像技术和动物行为学,明确各激素影响厌恶加工的神经内分泌机制。