大鼠注意定势转移任务模型的深入研究：种系和检测程序的影响

注意定势转移任务(attentional set-shifting task, AST)可用于特异性检测啮齿类动物前额叶皮层及其皮层下神经通路介导的认知灵活性, 是目前研究认知灵活性及其障碍神经基础的重要模型。本研究系统调查了大鼠种系和检测程序差异对AST结果的影响。通过比较Wistar和Sprague Dawley (SD)两个种系大鼠在七阶段和五阶段两种AST检测程序中的认知表现, 研究发现：(1) SD和Wistar大鼠前额叶认知功能存在差异, 后者的总体认知表现优于前者。尤其是Wistar大鼠在逆反学习阶段的达标训练次数及错误率显著低于SD大鼠, 表明Wistar大鼠具有更高的策略转换灵活性。(2)在AST测试中逆反学习和外维度定势转移是认知灵活性评价的核心指标。这两种认知转换过程分别以前期策略和注意定势建立为基础。结果显示在两种AST检测程序中Wistar和SD大鼠在逆反学习和/或外维度定势转移等复杂学习阶段的达标训练次数和错误率均高于其它简单关联学习阶段, 表明在目前实验条件下大鼠均表现出定势形成和转换困难的反应模式, 不同认知反应间的结构关系具有稳定性。这些结果提示大鼠前额叶皮质介导的认知灵活性存在种系差异, AST各阶段认知反应间的结构效度不受目前使用的大鼠种系和检测程序差异的影响, 扩展了对AST模型的认识。     

情绪记忆的鲜活性和准确性的关系*

采用记得/知道范式,以正性、负性和中性图片为实验材料,以32名大学本科生为被试,考察情绪记忆鲜活性和准确性的关系。结果发现,情绪记忆的记得成绩好于中性记忆,说明情绪记忆较中性记忆更具鲜活性;情绪记忆的鲜活性和准确性存在较大的关联,在正性、负性和中性图片上相关都达到了显著,表明情绪记忆的鲜活性与刺激中心细节的恢复相联系。     

问题解决中顿悟的原型位置效应的fMRI研究

科学发明创造中, 人们往往对一个问题百思不得其解, 但在看到某一启发性事物(原型)时, 突然产生顿悟, 继而发现解决问题的新思路。本研究以科学发明创造问题为实验材料, 采取“先呈现问题、后呈现原型”和“先呈现原型、后呈现问题”两种范式, 探讨问题解决中顿悟的原型位置效应, 并采用fMRI技术记录大脑的BOLD信号变化。结果发现：行为结果上, “问题在先”条件下正确率显著高于“原型在先”条件; 大脑激活结果上, 问题先导条件下的原型启发的大脑机制主要表现为左侧颞中回(left middle temporal gyrus)和左侧额中回(left middle frontal gyrus)的显著激活, “原型在先”条件下, 主要激活左侧扣带回(left cingulate gyrus)、左侧中央前回(left middle frontal gyrus)。     

任务与字频对汉字阅读中情绪价效应的影响

两个实验均以汉字为材料,采用2×3被试内设计,分别使用语义范畴判断和语音判断任务考察了汉字频率对阅读中情绪价效应的影响。结果发现：在语义任务中,情绪价与字频之间交互作用不显著,低频消极字和积极字的反应时均快于中性字,高频消极字的反应时也快于中性字,但高频积极字与中性字之间无差异。在语音任务中,情绪价与字频之间交互作用显著,低频消极字和积极字的反应时均快于中性字,而高频字的语音通达则不受情绪价的影响。汉字阅读中的情绪价效应不是自动化的过程,会受到字频与任务形式的影响。     

午睡剥夺对科学发明问题解决中的原型启发效应的影响

选取生态效度较高的科学发明问题材料(分为高启发量与低启发量两类),采用“1对1”和“8对8”的“学习-测试”实验范式,考察午睡剥夺对科学发明问题解决中的原型启发效应的影响.结果发现:午睡剥夺处理、范式(“1对1”和“8对8”)和材料启发量高低在原型激活率和问题解决率上主效应均显著,午睡剥夺和范式以及启发量高低在问题解决率以及原型激活率上的交互作用不显著.这一结果说明,午睡剥夺影响科学发明问题解决中的原型启发效应,这种影响是通过对启发信息应用和原型激活两个加工过程的影响而实现的.     

儿童数字线表征的发展——心理长度的影响

探讨儿童在数字线估计任务中心理长度的发展及其对数量表征模式的影响.选取7~9岁儿童共109名进行数字线估计任务测试,设置了10cm和20cm两种长度条件,要求儿童完成根据位置判断数字任务(position to number,PN任务).结果表明儿童在数字线PN任务中存在心理长度,且7岁儿童心理长度的范围超过10,随着儿童年龄的增长,他们的心理长度范围不断缩小;心理长度范围影响儿童的表征模式,随着心理长度范围的缩小,儿童的数字线表征出现从指数模式到线性模式的变化趋势;与表征模式的发展趋势一致,儿童估计的精确性随年龄增长逐渐提高.     

基于行为事件的履历资料评估

行为事件的履历资料评估能有效克服传统履历数据构思效度弱、情景限制多等问题。本研究结合某通信企业招聘工作,选取250名应聘者数据,结合关键事件法,通过对履历事件的行为锚定来评估应聘者的胜任特征。研究在多重比较行为履历资料、履历表数据、认知能力等多个指标组合对录用结果预测的回归模型基础上,检验新增指标的预测效度。结果表明,行为事件的履历资料评估具有效标关联效度,与其他工具组合使用时具有增量效度。     

Effective brain connectivity in children with reading difficulties during phonological processing

Using Dynamic Causal Modeling (DCM) and functional magnetic resonance imaging (fMRI), we examined effective connectivity between three left hemisphere brain regions (inferior frontal gyrus, inferior parietal lobule, fusiform gyrus) and bilateral medial frontal gyrus in 12 children with reading difficulties (M age=12.4, range: 8.11-14.10) and 12 control children (M age=12.3, range: 8.9-14.11) during rhyming judgments to visually presented words. More difficult conflicting trials either had similar orthography but different phonology (e.g. pint-mint) or similar phonology but different orthography (e.g. jazz-has). Easier non-conflicting trials had similar orthography and phonology (e.g. dime-lime) or different orthography and phonology (e.g. staff-gain). The modulatory effect from left fusiform gyrus to left inferior parietal lobule was stronger in controls than in children with reading difficulties only for conflicting trials. Modulatory effects from left fusiform gyrus and left inferior parietal lobule to left inferior frontal gyrus were stronger for conflicting trials than for non-conflicting trials only in control children but not in children with reading difficulties. Modulatory effects from left inferior frontal gyrus to inferior parietal lobule, from medial frontal gyrus to left inferior parietal lobule, and from left inferior parietal lobule to medial frontal gyrus were positively correlated with reading skill only in control children. These findings suggest that children with reading difficulties have deficits in integrating orthography and phonology utilizing left inferior parietal lobule, and in engaging phonological rehearsal/segmentation utilizing left inferior frontal gyrus possibly through the indirect pathway connecting posterior to anterior language processing regions, especially when the orthographic and phonological information is conflicting.     

Orienting attention in visual working memory reduces interference from memory probes

Given a changing visual environment, and the limited capacity of visual working memory (VWM), the contents of VWM must be in constant flux. Using a change detection task, the authors show that VWM is subject to obligatory updating in the face of new information. Change detection performance is enhanced when the item that may change is retrospectively cued 1 s after memory encoding and 0.5 s before testing. The retro-cue benefit cannot be explained by memory decay or by a reduction in interference from other items held in VWM. Rather, orienting attention to a single memory item makes VWM more resistant to interference from the test probe. The authors conclude that the content of VWM is volatile unless it receives focused attention, and that the standard change detection task underestimates VWM capacity.     

Indirect assessment of visual working memory for simple and complex objects

Previous research has shown that visual search performance is modulated by the current contents in visual working memory (VWM), even when the contents of VWM are irrelevant to the search task. For example, visual search is faster when the target--rather than a distractor--is surrounded by a shape currently held in VWM. This study uses the modulation of visual search by VWM to investigate properties of VWM. Participants wereasked to remember the color or the shape of novel polygons whose "goodness" of figure varied according to Garner's (1962) rotation and reflection transformation principle. During the memory retention interval, participants searched for a tilted line among vertical lines embedded inside colored polygons. Search was faster when the target--rather than a distractor--was enclosed by the remembered polygons. The congruity effect diminished with increasing memory load and decreasing figure goodness. We conclude that congruity effects in visual search can indirectly assess VWM representation strength.