科学触角

<正>婴儿小睡与记忆德国波鸿鲁尔大学心理学系将216名健康足月的6个月大和12个月大的婴儿作为被试对象,研究学习之后的睡眠是否促进了陈述性记忆的巩固。研究人员让这些婴儿脱掉和操纵布袋玩偶上的一个连指手套,来测试他们在4或24小时之后回忆一个新学到的行为的能力。研究人员使用一种活动变化记录仪监测了这些婴儿的睡眠一觉醒模式,把在学习之后没有小睡的婴儿与在4小时的学习时间里至少小睡了     

记忆及记忆系统的神经生物学研究

陈述性记忆系统和非陈述性记忆系统是记忆系统中的两个主要系统；突触的可塑性变化和不同的蛋白质是记忆痕迹的基础；ＬＴＰ和ＬＴＤ是记忆形成过程中细胞活动特性的表现；不同的学习记忆过程会引起不同的基因表达并产生不同的蛋白质。     

学习与记忆

学习和记忆不是单一独立的过程。学习是获得新信息的过程，而记忆则是将学到的知识加以保留的过程。记忆可以分成两类：一类是陈述性记忆，是对人、地点和事物相关知识的有意识的获得，它发生在高度进化的脊椎动物脑部，主要是问脑结构中；另一类是非陈述性记忆，是     

羞耻性自传体记忆: 基于自我文化差异的对比研究

基于Markus和Kitayama的自我文化理论, 考察羞耻情绪在中美两国文化下的差异。69名中国大学生和65名美国大学生作为被试, 每个被试被要求回忆一个自己亲身经历的羞耻性事件。之后根据羞耻自传体记忆的特点及理论假设, 制定了编码规则。根据编码规则, 对每个记忆进行编码统计。研究结果显示: 1) 中国被试羞耻性自传体记忆的具体程度高于美国被试; 2)中国被试的羞耻记忆出现更多人际关系的内容; 3)中国被试更多报告羞耻事件发生在童年和青春期, 更多涉及学校和老师的评价。     

远志皂苷和茯苓多糖对学习记忆的改善作用及其机制研究

目的观察PSP(远志皂苷和茯苓多糖Polygalaceae saponins and Pachymaran)对多种化学药物所致学习记忆障碍模型小鼠学习记忆能力的改善作用,探讨其可能的作用机制.方法本研究通过跳台实验和避暗实验观察PSP高、中、低剂量组对记忆获得、巩固和再现模型小鼠学习记忆能力的影响;测定记忆获得障碍模型小鼠脑组织乙酰胆碱酯酶活性(ACHE);测定记忆巩固障碍模型小鼠脑组织超氧化物歧化酶(SOD)活性和丙二醛(MDA)活性.结果 PSP能使记忆获得障碍模型小鼠5 min内学习及记忆的错误次数减少并延长潜伏期;PSP能使记忆获得、巩固障碍模型小鼠5 min内错误次数减少并延长潜伏期;PSP能使记忆再现障碍模型小鼠5 min内错误次数减少并延长潜伏期;PSP能有效降低记忆获得障碍模型小鼠脑组织中乙酰胆碱酯酶(ACHE)活性;PSP能有效提高记忆巩固障碍模型小鼠脑组织中超氧化物歧化酶(SOD)活性并降低丙二醛(MDA)活性.结论 PSP能改善模型小鼠学习记忆能力的作用机制可能是通过抑制脑内乙酰胆碱酯酶合成、减少乙酰胆碱水解、提高脑组织内ACHE活性而发挥改善学习记忆的作用;PSP能有效提高SOD活性并减低MDA活性,从而减少氧自由基对小鼠损伤而发挥改善学习记忆的作用.     

知识转化为能力的条件与策略——基于不同类型知识间的关系

知识与能力的关系不是线性的,知识向能力转化受知识类型、学习策略、学习情境等中介变量的制约.研究知识向能力转化的条件与策略是深化新课程改革,实施素质教育的迫切需要.新的知识观认为知识可分为三大类:陈述性知识、程序性知识和策略性知识.知识转化为能力,需陈述性知识与程序性知识之间相互转化,策略性知识调控陈述性知识和程序性知识的学习;问题解决检验个体能力的高低.     

杏仁核参与情绪记忆的脑功能成像研究述评

脑功能成像技术近年来已应用于情绪记忆的研究,相关的研究结果扩展了依据动物实验所得到的有关结论.作者主要对近年来情绪记忆的编码和提取阶段的脑成像研究进行了综述.研究表明,杏仁核在情绪记忆中的作用不仅局限在巩固阶段,它的作用在编码过程的初期已显示出来,并参与记忆的提取过程.脑区相关和联结模型强调了杏仁核与内侧颞叶等之间的交互作用.已有的研究还表明,刺激类型是影响情绪记忆的重要因素之一.杏仁核还参与对情绪的刺激类型、情绪记忆的生动感和主观性的加工.在今后的研究中将多种神经科学的技术相结合会更深入地揭示情绪记忆的脑机制.     

中药复方SMⅠ对小鼠学习记忆功能障碍的影响

目的:探讨中药复方SMⅠ对小鼠记忆功能障碍的影响及其可能的机制。方法:用东莨菪碱、亚硝酸钠及乙醇分别建立记忆获得障碍、记忆巩固障碍和记忆再现障碍模型,用跳台法观察SMⅠ对记忆障碍动物学习记忆能力的影响。同时测定东莨菪碱记忆获得障碍小鼠脑组织中乙酰胆碱酯酶的活性。结果:SMⅠ可以减少东莨菪碱记忆获得障碍小鼠跳台累计触电时间(P<0 05),延长亚硝酸钠记忆障碍小鼠记忆测试中潜伏期的时程(P<0 05),减少其错误次数(P<0 05),也可以减少乙醇记忆再现障碍小鼠记忆测试的错误次数(P<0 05)。SMⅠ可以降低东莨菪碱记忆获得障碍小鼠脑乙酰胆碱酯酶活性(P<0 05)。结论:中药复方SMⅠ对记忆获得、记忆巩固及记忆再现障碍有明确的改善作用,其机制可能与影响中枢胆碱能系统有关。     

表象编码对事件性前瞻记忆的影响

为了考察表象编码对事件性前瞻记忆的影响,以汉字为材料,将60名大学本科生随机分到标准编码组和表象编码组中,每组被试均完成材料相同的三个阶段的实验任务.实验结果表明,表象编码对事件性前瞻记忆具有一定的促进作用.无论是标准编码组还是表象编码组,将意向行为与背景相联系都能够产生高水平的前瞻记忆表现.与标准编码条件相比,表象编码条件下被试对线索词和诱发词的反应时更短.此外,与国外使用英文字词的研究结果相比,以汉字为实验材料,被试对线索词和诱发词的反应时均短于词汇判断任务的平均反应时,并未出现线索干扰和诱发干扰效应.     

遗忘规律对高职英语教学的启示探究

该文旨在针对高职英语教学中存在的学生记忆知识困难现象,根据艾宾浩斯记忆规律、痕迹衰退理论、前后信息干扰说、提取失败说、佛洛依德压抑说等记忆与遗忘理论,提出了高职英语教学中有效巩固学生记忆、防止遗忘的策略,包括科学安排记忆材料、过度学习与及时复习、精细加工记忆材料、提升学生的积极主动性等。教师在高职英语教学中应根据相关理论科学安排教学,引导学生灵活选用学习方式,提高英语学习效率。     

What can false memory tell us about memory impairments in Alzheimer’s disease?

The range of memory impairments associated with Alzheimer’s disease (AD) has been a focus for psychological and clinical re-searchers for many years. In addition to investigations of AD patients’ veridical memory using traditional recognition memory tasks, a number of recent studies have focused on false memories to reveal the underlying causes of memory impairment in AD. Studies comparing illusory memories between AD patients and healthy older people have revealed various differences in memory deficits between the development of AD and the typical aging processes. Here, we review 3 types of memory illusions tested in AD patients: associative memory illusions, fluency-based false memories and source memory errors. By comparing AD patients with healthy older adults, we sought to analyze the mechanisms underlying AD-related memory impairments at different stages of memory processing, including encoding, retrieval and monitoring. This comparison revealed that AD patients exhibit an impaired ability to establish and utilize gist representations at the encoding stage and impairments in processing on the basis of familiarity and recollection at the retrieval stage. Consequently, patients with AD have access to less information when making memory judgments. As a result, they become more susceptible to the effects of item fluency, which can be manipulated during the retrieval stage. Furthermore, with impaired source memory monitoring abilities, the capacity of AD patients to suppress memory illusions is compromised. Based on these findings, we propose that the study of false memories constitute a critical tool for elucidating the memory impairments involved in AD. Further explorations of these memory impairments will have practical significance for the diagnosis and treatment of AD in the future.     

Gender difference in the effect of daytime sleep on declarative memory for pictures

Objective: To investigate gender difference in the effects of daytime sleep on item and source memories, which are dissociable elements of declarative memory, and the effects of sleep on recollection and familiarity, which are two processes underlying recognition. Methods: Participants saw a series of pictures with either blue or red background, and were then given a pretest for item and source memories. Then males and females respectively were randomly assigned either to a wake or a sleep condition. In the wake condition, participants remained awake until the posttest; in the sleep condition, participants slept for 1 h until awakened and asked to remain awake until the posttest. Results: Daytime sleep contributed to retention of source memory rather than item memory in females, whereas males undergoing daytime sleep had a trend towards increased familiarity. For females, however, neither recollection nor familiarity appeared to be influenced by daytime sleep. Conclusion: The mechanism underlying gender difference may be linked with different memory traces resulting from different encoding strategies, as well as with different electrophysiological changes during daytime sleep.     

一种混合模糊联想记忆网络

本文改进了Ｋｏｓｋｏ．Ｂ提出的最大最小联想记忆网络的模糊Ｈｅｂｂ关系编码规则,给出了一种新的学习算法,新算法克服了Ｋｏｓｋｏ．Ｂ算法的缺陷,在一定条件下,本文的学习算法能将模式对完整地联想出来．另外,本文在分析网络的容错性及稳定性的基础上,提出了一种五层混合模糊联想记忆网络,五层混合网络具有良好的联想容错能力．实验结果表明,本文的学习算法及混合网络是有效的．     

Sleep inspires insight

Insight denotes a mental restructuring that leads to a sudden gain of explicit knowledge allowing qualitatively changed behaviour. Anecdotal reports on scientific discovery suggest that pivotal insights can be gained through sleep. Sleep consolidates recent memories and, concomitantly, could allow insight by changing their representational structure. Here we show a facilitating role of sleep in a process of insight. Subjects performed a cognitive task requiring the learning of stimulus-response sequences, in which they improved gradually by increasing response speed across task blocks. However, they could also improve abruptly after gaining insight into a hidden abstract rule underlying all sequences. Initial training establishing a task representation was followed by 8 h of nocturnal sleep, nocturnal wakefulness, or daytime wakefulness. At subsequent retesting, more than twice as many subjects gained insight into the hidden rule after sleep as after wakefulness, regardless of time of day. Sleep did not enhance insight in the absence of initial training. A characteristic antecedent of sleep-related insight was revealed in a slowing of reaction times across sleep. We conclude that sleep, by restructuring new memory representations, facilitates extraction of explicit knowledge and insightful behaviour.     

Reverse replay of behavioural sequences in hippocampal place cells during the awake state

The hippocampus has long been known to be involved in spatial navigational learning in rodents, and in memory for events in rodents, primates and humans. A unifying property of both navigation and event memory is a requirement for dealing with temporally sequenced information. Reactivation of temporally sequenced memories for previous behavioural experiences has been reported in sleep in rats. Here we report that sequential replay occurs in the rat hippocampus during awake periods immediately after spatial experience. This replay has a unique form, in which recent episodes of spatial experience are replayed in a temporally reversed order. This replay is suggestive of a role in the evaluation of event sequences in the manner of reinforcement learning models. We propose that such replay might constitute a general mechanism of learning and memory.     

多功能SMPs在生物医学领域的研究进展

形状记忆聚合物(SMPs)是一种可以感知—响应外界刺激,并调整自身力学参数,从而回复预先设定形状的智能材料,在自动化、包装材料、微-纳米电子机械等领域具有良好的使用价值。为了进一步拓展形状记忆材料的实际应用范围,满足一些特殊领域(如航空航天、生物医学)的功能化要求,弥补材料单一形状记忆功能所造成的不足,多功能SMPs越来越受到科学家的广泛关注。概述了多功能SMPs的研究进展,综述了多功能SMPs在生物医学工程上的应用,并展望其发展前景。     

Sleep-dependent memory consolidation

The concept of 'sleeping on a problem' is familiar to most of us. But with myriad stages of sleep, forms of memory and processes of memory encoding and consolidation, sorting out how sleep contributes to memory has been anything but straightforward. Nevertheless, converging evidence, from the molecular to the phenomenological, leaves little doubt that offline memory reprocessing during sleep is an important component of how our memories are formed and ultimately shaped.     

并行处理机中交叉存储器的冲突分析

本文采用模拟分析方法对并行处理机中交叉存储器的访问冲突及有效带宽的计算进行了研究和探讨。在W. Oed和O. Lange的基础上,分析了当三条或多条向量流同时请求访问存储器时,向量流之间的相互作用,以及在几种稳定状态下的性能结果。     

共同目击者的错误记忆

共同目击者目击事件后往往会一同讨论发生的事件,而这种讨论影响目击者的记忆准确性,使共同目击者的记忆趋向一致,从而影响目击者证词的有效性。这引起了研究者们的注意,并开始深入研究共同目击者的错误记忆。相关的研究主要集中于共同目击者错误记忆研究的方法、记忆准确性、记忆自信度以及记忆一致性等方面,并对共同目击者错误记忆的产生进行理论解释。这些研究给我们极大启示,并要求我们继续开拓新的研究思路与设想。     

An Incremental Time—Delay Neural Network for Dynamical Recurrent Associative Memory

An incremental time-delay neural network based on synapse growth,which is suitable for dynamic control and learning of autonomous robots,is prooposed to improve the learning and retrieving performance of dynamical recurrent associative memory architecture.The model allows steady and continuous establishment of associative memory for spatio-temporal regularities and time series in discrete sequence of inputs.The inserted hiddewn units can be taken as the Long-term memories that expand the capacity of network and sometimes may fade away under certain condition.Preliminary experiment has shown that this incremental netwrok may be a promising approach to endow autonomous robots with the ability of adapting to new data without destroying the learned patterns.The system also bendfits from its potential chaos character for emergence.