Dietary restriction inhibits spatial learning ability and hippocampal cell proliferation in rats1

Abstract: We investigated the effect of dietary restriction on spatial learning ability and hippocampal cell proliferation in adult rats using two spatial learning tasks and immunohistochemical staining with 5‐bromo‐2′‐deoxyuridine (BrdU). Sixteen rats were divided into restricted or ad lib feeding groups at 70 days of age, and were trained in the delayed‐matching‐to‐place (DMTP) task (a working memory task) from 93 days of age, and then the Morris water maze task (a reference memory task). Dietary restriction had no effect on the DMTP task with 30 s delay and on the water maze task. However, in the DMTP task with 30 min delay, restricted rats performed significantly more poorly than ad lib rats. Quantitative analysis of hippocampal cell proliferation revealed that the density of newborn cells in restricted rats was significantly lower than that in ad lib rats. These results suggest that a loss of proliferating capacity in the hippocampus may be a candidate for an anatomical and biological basis for the cognitive decline caused by dietary restriction.     

几何模块论的局限性——来自梯形实验的证据

以往研究表明幼儿主要依赖几何信息进行再定向,但这些研究大多使用矩形空间。在本研究中,幼儿所处的空间为几何信息更丰富,目标物体所在位置确定的梯形。结果发现,幼儿并不会利用新增的几何信息确定目标物体,仍然去正确位置的对角寻找,表现出的寻找模式与矩形空间一样,这说明幼儿在空间再定向任务中对几何信息的利用很有限。此外,录像分析的结果发现,幼儿在面向梯形两底边时会更多地且径直地走向正确位置或对角,这种寻找过程上的特点表明他们可能基于空间轴朝向结合左右方位感表征物体位置     

视觉空间注意研究中的N2pc成分述评

N2pc与空间选择性注意密切相关, 反映了一种对当前任务相关刺激的注意分配过程。N2pc自我特性的研究主要涉及理论解释、测量方法、源定位以及影响因素等方面, 而其实验范式主要有视觉搜索和视觉短时记忆搜索两种范式。以N2pc为指标的研究主要分为与视觉空间注意相关的基础性研究和应用性扩展研究。今后N2pc的研究应该在不断深入细化自身特性研究、做好基础性研究的同时, 更多的向应用性扩展研究拓展。     

Modes of spatial coding in the Simon task*

Many models of the Simon effect assume that categorical spatial representations underlie the phenomenon. The present study tested this assumption explicitly in two experiments, both of which involved eight possible spatial positions of imperative stimuli arranged horizontally on the screen. In Experiment 1, the eight stimulus locations were marked with eight square boxes that appeared at the same time during a trial. Results showed gradually increasing Simon effects from the central locations to the outer locations. In Experiment 2, the eight stimulus locations consisted of a combination of three frames of spatial reference (hemispace, hemifield, and position relative to the fixation), with each frame appearing in different timings. In contrast to Experiment 1, results showed an oscillating pattern of the Simon effect across the horizontal positions. These findings are discussed in terms of grouping factors involved in the Simon task. The locations seem to be coded as a single continuous dimension when all are visible at once as in Experiment 1, but they are represented as a combination of the lateral categories (“left” vs. “right”) with multiple frames of reference when the reference frames are presented successively as in Experiment 2.     

The impact of children’s lexical and morphosyntactic knowledge on narrative competence development: A prospective cohort study

The authors investigate the contribution of children's early comprehension of relational terms and morphosyntactic knowledge to the development of narrative competence in kindergarten and Grade 1. Narrative competence was assessed through the cohesion, coherence, and structure of children’s productions. The participants in this study were 714 Italian children. The authors measured their oral narrative competence through a storytelling task at the beginning and end of the kindergarten year. A total of 115 children were randomly selected and followed through Grade 1, and their narrative competence was measured again. According to the path analysis model, early morphosyntactic knowledge contributes to explain narrative competence in Grade 1. Early comprehension of relational terms contributes to narrative competence at the end of the school year. These findings confirm the importance of exploring the influence of early language skills on narrative competence development and suggests early intervention at the level of language antecedents of narrative competence.     

成人空间视角采择的自动性

设计新的空间视角采择任务,考察成人空间视角采择的自动性。结果发现：（1）在other任务中,随着人偶与被试的角度差异增加,反应时和错误率升高。（2）在self任务中,空间关系一致时正确率高于不一致时,且150°-180°间的一致性效应不显著;随着角度差异增加,反应时升高;小球与人偶的空间关系和空间关系的一致性交互作用不显著。本研究结果表明：本实验任务对成人而言是一个有效的空间视角采择任务;成人可以自动地做空间视角采择;人偶与被试的角度差异影响成人空间视角采择的自动性;小球与人偶的空间关系不影响成人空间视角采择的自动性。本研究首次证明了成人可以自动做空间视角采择。     

动词理解中空间表征的激活过程

探讨动词理解中空间表征的激活过程。被试听以不同空间轴向动词作谓语的句子后辨认视觉刺激的形状。实验1以肯定句为材料探讨语义理解对视知觉任务的影响。实验2以客观原因否定句为材料排除句子表征的影响。实验3以主观原因否定句为材料探讨动词空间元素的激活机制。总的结果表明,动词理解过程中激活其表征中的空间元素,这种激活是自动的、非策略性的,不受情境中客观原因或主观意愿否定的影响。动词理解空间效应反映了语言表征中的知觉运动特征     

物体位置与空间关系的心理表征

外界环境中物体位置与空间关系在记忆中如何表征,一直是空间认知研究领域探讨和争论的热点问题。该文从空间表征的参照框架、朝向特异性、组织结构和存储内容四个方面,系统回顾了近年来对空间表征形成机制与内在特征的理论探讨。在此基础上,进一步讨论了当前空间表征研究中存在的生态效度问题,以及以后将虚拟环境技术引入到空间认知研究中的发展趋势     

参照系冲突对表象更新的影响

以三维场景图片为学习材料,通过系统操纵参照系之间的冲突,在四个实验中考察了两种不同表象更新任务的参照系冲突效应。结果发现：（1）参照系冲突对以自我为中心的表象更新有显著影响,但对以场景为中心的表象更新影响相对较小,从而导致以自我为中心表象更新相对于以场景为中心的表象更新的优势效应减小直至消失。（2）旋转者身体倾斜与场景倾斜引发的参照系冲突效应具有不对等性：由于整个场景倾斜引发的参照系冲突效应大于由于旋转者身体倾斜引发的参照系冲突效应。（3）与场景同时倾斜的局部空间参照系降低了以场景为中心表象更新任务的参照系冲突效应,但对以自我为中心表象更新任务的参照系冲突效应没有影响。这些结果表明两种表象更新任务具有不同的认知加工机制,并进一步扩展了Presson等提出的空间更新参照系冲突模型     

视觉工作记忆在视觉搜索中的作用

视觉工作记忆在视觉搜索中的作用远比偏向竞争模型所描述的要复杂,个体能根据当前任务要求灵活地利用工作记忆来引导注意选择。在系统回顾已有研究的基础上,从客体工作记忆、空间工作记忆和执行工作记忆3个方面探讨了视觉工作记忆在视觉搜索中的作用。根据近期的研究,文章在最后对视觉工作记忆在视觉搜索中的作用做了7点总结,并对已往研究中存在的若干问题给予了解释,指出未来应该从前瞻记忆和内隐记忆等角度对视觉搜索中所涉及的视觉记忆进行深入研究