中年Ⅱ型糖尿病人记忆损伤特点

本研究主要探讨中年Ⅱ型糖尿病人的记忆损伤特征。研究选取病人和对照各30人,控制年龄(65岁以下。病人组平均53岁,正常组52岁)、教育水平和相关疾病等因素。测试数字符号、数字工作记忆广度、动作记忆和无意义图形再认4项认知任务。结果发现：(1)病人组数字符号测试显著低于正常组;(2)在支持性条件记忆自由回忆中,病人组在有动作演练的高语义关联和无动作演练的低语义关联项目上显著低于对照组。出现分离现象;(3)在线索回忆中,病人组与对照组差异不显著;(4)两组数字工作记忆广度、无意义图形再认的成绩无差异。根据SPT(subject—performed task)研究理论对结果进行了分析,得出结论：中年Ⅱ型糖尿病人记忆的一般性信息加工能力未表现出受损,但特异信息加工受到损伤,并可能预测随年龄及病程进行而表现出一般性信息加工能力受损。     

Alzheimer病人记忆损害特征的研究

目的了解AD病人记忆损害的特征。方法采用多维记忆评估量表中的12个分测验对30例临床诊断可能的Alzheimer病患者及与病人组相匹配的30例正常受试进行记忆功能的测定。结果AD组几乎在所有的分测验和指数分上均差于对照组。AD轻度组仅在自由组词、残图命名、空间广度、常识记忆等4个分测验及记忆广度、内隐记忆等2个指数分上与对照组之间无明显差异。中重度组则在所有分测验和指数分均差于对照组。经以教育年限为协变量校正后,轻度与中重度组在自由组词、残图命名、经历定向、常识记忆、自由回忆、内隐记忆、日常记忆等分测验和指数分上存在明显差异。12个分测验成绩的比较发现,负荷外显记忆的各个分测验的成绩均较差,负荷内隐记忆的两个分测验的成绩较好。结论轻度AD病人存在着广泛的外显记忆障碍,中重度AD病人除了存在外显记忆障碍外还表现出内隐记忆和日常生括记忆的障碍。这一结果提示人类大脑中存在着多个记忆系统,不同系统受损所导致的记忆障碍不同。     

学科领域知识和学业成绩对工作记忆广度的影响

引入Alexander领域知识概念形成数学学科领域知识,以七年级有理数单元为研究材料,编写问卷和E-Prime实验程序,筛选60名初中生为被试,考察数学学科领域知识和学业成绩对工作记忆广度的影响。研究发现:(1)学优生的认知过程知识和问题条件知识显著高于学困生,而学理内容知识差异不显著;(2)在简单加工任务上,学优生和学困生工作记忆广度差异不显著。在复杂任务上,学优生的工作记忆广度都显著高于学困生;(3)当工作记忆广度任务中存储部分的词语和数学学科领域知识相关时,问题条件知识分数和认知过程分数能够显著地预测工作记忆广度。而不相关时,仅问题条件知识分数能够显著地预测工作记忆广度。     

工作记忆广度与自我损耗的关系

以往研究表明,工作记忆能力高的个体在自我控制方面也表现得更好,通过考察工作记忆广度（working memory span, WMS）与自我损耗的关系,有助于揭示这种现象的内在机制。66名被试随机分为损耗组和控制组,采用自动化操作广度测验测量WMS。双任务实验中,任务一为情绪抑制任务,任务二为Stroop任务。结果发现,损耗组的Stroop效应明显高于控制组。进一步分析显示,损耗组中高WMS被试的自我损耗效应要强于低WMS被试,此结果表明：高WMS个体在自我控制任务中表现得更好并不是因为固有的自我控制能量水平更高,而是因为他们倾向于在自我控制过程中投入更多能量。     

工作记忆广度：资源限制、记忆消退还是转换机制？

为了检验工作记忆广度有限性的3种假说,即资源限制假说、记忆消退假说和转换机制假说,实验要求被试首先完成一项转换效率任务,然后完成工作记忆广度任务。结果发现,加工负荷对工作记忆广度具有重要影响,保持时间不影响工作记忆广度,转换效率与工作记忆广度也没有显著相关。实验结果支持工作记忆广度受认知资源限制的观点     

比喻性成语对文章段落回忆的影响

本研究采用随意学习的实验范式,探讨了结句中是否包含比喻性成语以及被试的工作记忆容量大小对文章段落回忆成绩的影响.实验中所有被试被要求阅读6个说明体的文章段落,然后接受一个有提示的回忆测验.研究发现(1)所有被试对结句中包含比喻性成语的段落回忆成绩比结句中没有比喻性成语的段落好.(2)结句中是否包含比喻性成语和被试工作记忆容量之间存在着交互作用.若结句中包含比喻性成语,段落的回忆成绩不受被试工作记忆容量的制约,反之则会.这些结果可能表明,比喻性成语的某些特点,如形象性或易记性,作为一种辅助手段促进了被试对文章内容的记忆、保持和回忆.     

数学学习困难初中生的记忆广度特点

记忆广度包括短时记忆广度和工作记忆广度,为揭示数学学习困难学生认知缺损特点,筛选103名初中生（平均年龄12.57岁）,比较数学困难学生（49名）与数学优秀学生（54名）的记忆广度差异,通过词语系列任务、阅读广度任务以及倒背数字任务,分别测查了短时记忆、言语工作记忆以及数字工作记忆。结果发现,数困组与优秀组的学生在词语系列任务中没有显著差异（t＝-1.59, p>.05）,在阅读广度任务中,具有显著差异（t＝-2.38, p<.05）,在倒背数字任务中具有极其显著的差异（t＝-4.69, p<.01）。阅读广度和倒背数字之间具有显著相关(r=.24, p<.05),词语系列任务与阅读广度(r=.19, p>.05)和倒背数字任务(r=.05, p>.05)之间不存在显著相关。研究表明,在具有干扰情况的任务更能有效预测数学成绩,数学学习困难的认知缺损主要是对抗干扰的能力不足,而非简单的短时记忆广度。     

高低PTSD症状个体的定向遗忘效应

本研究为考察高PTSD症状个体的记忆抑制功能特点,分别采用定向遗忘任务的单词范式和词表范式,以中性词语为实验材料,以不同程度PTSD症状的监狱犯人为被试进行研究。所有被试均被要求学习两组词语,记住其中一组(TBR),并忘记另一组(TBF)。学习完成后,以自由回忆的方式对两组词语进行测验。结果表明,无论是单词方式还是词表方式,高PTSD症状的被试在TBR和TBF上的回忆成绩的差异都比低症状被试要小;研究结果提示高PTSD症状者在抑制无关信息方面的功能上有所缺损。通过两种不同定向遗忘方式的设计区别,考虑这种缺损更可能发生在记忆的提取阶段。     

8岁到成年期工作记忆广度的发展

工作记忆与认知能力、智力和学习能力有密切的联系.本研究采用横断研究的方法,测量了213名8岁到成年期被试的数字、词语和视空间工作记忆广度,探查了工作记忆广度的发展情况.结果发现,数字工作记忆广度在此期间持续增长,词语广度在18岁达到最高,视空间工作记忆广度在14-16岁达到高峰.不同任务的工作记忆广度具有相似的发展趋势,但工作记忆的平均广度分数与Pascual-Leone模型的预测并不一致.     

基于客体工作记忆内容的保持对时间判断的影响

本研究通过操作工作记忆内容的有效性,探讨了记忆内容的保持对时间判断的影响。采用不规则的客体作为实验材料,使时间任务中的刺激与工作记忆内容匹配或不匹配。实验1采用工作记忆和时间判断的双任务范式,要求被试首先记忆一个客体,然后在每个试次的最后判断测试刺激是否与记忆项相同。在延迟阶段,被试判断连续出现的两个刺激的时距哪个更长（或更短）。实验2中,要求被试忽略第一个刺激,仅完成时间判断任务。结果发现,相比单任务的计时,双任务条件下,工作记忆内容的保持延长了时间判断的时间。而且,在记忆匹配和知觉匹配条件下,匹配刺激呈现的时间越长,正确率越低,反应时越长。这说明记忆内容的保持增加了决策的难度,工作记忆内容对时间判断的可能是由记忆内容引起的注意定向造成的。     

Differential memory impairment in dementia with Lewy bodies and Alzheimer's disease

This study was conducted in order to elucidate the functioning of the Central Executive System of Working Memory (WM) and to clarify the status of other cognitive functions in Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Fourteen DLB, 22 AD, and 23 control subjects were assessed with the dual task paradigm and other cognitive tests. When compared with controls, DLB subjects performed more poorly in concurrent conditions on semantic WM tasks, and AD subjects performed more poorly on the spatial WM task. The DLB subjects had an inferior verbal span and AD subjects, an inferior recall on the CVLT. These data suggest relative impairments of verbal and semantic WM in DLB and relative impairments of spatial WM and verbal episodic memory in AD.     

The Measurement of Verbal Working Memory Capacity and Its Relation to Reading Comprehension

Ninety-four subjects were tested on the Daneman and Carpenter (1980) reading span task, four versions of a related sentence span task in which reaction times and accuracy on sentence processing were measured along with sentence-final word recall, two number generation tasks designed to test working memory, digit span, and two shape-generation tasks designed to measure visual-spatial working memory. Forty-four subjects were retested on a subset of these measures at a 3-month interval. All subjects were tested on standard vocabulary and reading tests. Correlational analyses showed better internal consistency and test-retest reliability of the sentence span tasks than of the Daneman-Carpenter reading span task. Factor analysis showed no factor that could be related to a central verbal working memory; rotated factors suggested groupings of tests into factors that correspond to digitrelated tasks, spatial tasks, sentence processing in sentence span tasks, and recall in sentence span tasks. Correlational analyses and regression analyses showed that the sentence processing component of the sentence span tasks was the best predictor of performance on the reading test, with a small independent contribution of the recall component. The results suggest that sentence span tasks are unreliable unless measurements are made of both their sentence processing and recall components, and that the predictive value of these tasks for reading comprehension abilities lies in the overlap of operations rather than in limitations in verbal working memory that apply to both.     

Recall of words heard in noise

The aim of the study was to explore if recall of words and recognition of sentences orally presented was affected by a background noise. A further aim was to investigate the role of working memory capacity in performance in these conditions. Thirty‐two subjects performed a word recall and a sentence recognition test. They repeated each word to ensure that they had heard them. A reading span test measured their working memory capacity. Performance on the word recall task was impaired by the background noise. A high reading span score was associated with a smaller noise effect, especially on recall of the last part of the word list. Copyright © 2007 John Wiley & Sons, Ltd.     

Production and identification repetition priming in amnestic mild cognitive impairment

The experiment reported here examined implicit memory function, as measured through repetition priming, in amnestic mild cognitive impairment (MCI) to examine whether impairments exist in this aspect of memory function. Young adults, healthy older controls, Alzheimer's disease patients, and MCI participants were asked to perform two types of implicit memory tests (word stem completion and threshold identification repetition priming tasks), as well as a recognition test for studied items. As expected, young adults performed better than the other participants on the recognition test and the word stem completion task; there was equivalent priming across groups on the word identification task. While both the older control and MCI participants showed lower levels of priming on the word stem completion task relative to the young adults, the magnitude of priming was equivalent for these two groups, and reliably greater than that of the dementia participants. These results suggest that not all aspects of memory function are impaired in MCI relative to healthy aging.     

Temporal–contextual processing in working memory: Evidence from delayed cued recall and delayed free recall tests

Three experiments are reported that addressed the nature of processing in working memory by investigating patterns of delayed cued recall and free recall of items initially studied during complex and simple span tasks. In Experiment 1, items initially studied during a complex span task (i.e., operation span) were more likely to be recalled after a delay in response to temporal–contextual cues, relative to items from subspan and supraspan list lengths in a simple span task (i.e., word span). In Experiment 2, items initially studied during operation span were more likely to be recalled from neighboring serial positions during delayed free recall than were items studied during word span trials. Experiment 3 demonstrated that the number of attentional refreshing opportunities strongly predicts episodic memory performance, regardless of whether the information is presented in a spaced or massed format in a modified operation span task. The results indicate that the content–context bindings created during complex span trials reflect attentional refreshing opportunities that are used to maintain items in working memory.     

Increases in Intrusion Errors and Working Memory Deficit of Poor Comprehenders

This study tests the hypothesis that the ability to inhibit already processed and actually irrelevant information could influence performance in the listening span test (Daneman & Carpenter, 1980) and have a crucial role in reading comprehension. In two experiments, the listening span test and a new working memory test were given to two groups of young adults, poor and good comprehenders, matched for logical reasoning ability. In Experiment 1, the poor comprehenders had a significantly lower performance in the listening span test associated to a higher number of intrusions-that is, recalled words that, in spite of being in sentence form, were not placed in the last position. In Experiment 2, a new working memory test was devised in order to analyse more effectively the occurrence of intrusions. Subjects were required to listen to a growing series of strings of animal and non-animal words. Whilst listening, they had to detect when an animal word occurred, and at the end of each series they had to recall the last word of each string. The poor comprehenders obtained a significantly lower performance in the memory task and made a higher number of intrusions, particularly of animal words.     

Effects of post-encoding wakeful rest and study time on long-term memory performance

Recent work shows that post-encoding wakeful rest, in contrast to a cognitive task delay period, supports memory performance. The present study aimed at investigating whether study time modulates the impact of post-encoding rest on delayed memory performance. Healthy young adults were allocated to one of two “study time” groups (fixed-paced vs. self-paced). Participants encoded two word lists. After immediate recall of one word list, participants wakefully rested for 8?min, after the other, they performed a visual problem solving task. A delayed recall took place at the end of the experimental session (Experiment 1) and again after 7 days (Experiment 1?+?2). We found that participants in the self-paced group outperformed those in the fixed-paced group. In Experiment 1, participants showed higher memory performances after 7 days in the resting condition independent of study time. No significant differences between post-encoding (rest vs. problem solving) and study time conditions were found in Experiment 2. Combined analyses of both experiments revealed that an additional recall (Experiment 1) supported memory retention in both post-encoding conditions. Our findings suggest that resting is beneficial over the long term, but only when the encoded information is repeatedly retrieved at the end of a learning session.     

Stimulus similarity decrements in children's working memory span

Two experiments investigated the impact of the relationship between processing and storage stimuli on the working memory span task performance of children aged 7 and 9 years of age. In Experiment 1, two types of span task were administered (sentence span and operation span), and participants were required to recall either the products of the processing task (sentence-final word, arithmetic total) or a word or digit unrelated to the processing task. Experiment 2 contrasted sentence span and operation span combined with storage of either words or digits, in tasks in which the item to be remembered was not a direct product of the processing task in either condition. In both experiments, memory span was significantly greater when the items to be recalled belonged to a different stimulus category from the material that was processed, so that in sentence span tasks, number recall was superior to word recall, and in operation span tasks, word recall was superior to number recall. Explanations of these findings in terms of similarity-based interference and response competition in working memory are discussed.     

Does Controlling for Temporal Parameters Change the Levels-of-Processing Effect in Working Memory?

The distinguishability between working memory (WM) and long-term memory has been a frequent and long-lasting source of debate in the literature. One recent method of identifying the relationship between the two systems has been to consider the influence of long-term memory effects, such as the levels-of-processing (LoP) effect, in WM. However, the few studies that have examined the LoP effect in WM have shown divergent results. This study examined the LoP effect in WM by considering a theoretically meaningful methodological aspect of the LoP span task. Specifically, we fixed the presentation duration of the processing component a priori because such fixed complex span tasks have shown differences when compared to unfixed tasks in terms of recall from WM as well as the latent structure of WM. After establishing a fixed presentation rate from a pilot study, the LoP span task presented memoranda in red or blue font that were immediately followed by two processing words that matched the memoranda in terms of font color or semantic relatedness. On presentation of the processing words, participants made deep or shallow processing decisions for each of the memoranda before a cue to recall them from WM. Participants also completed delayed recall of the memoranda. Results indicated that LoP affected delayed recall, but not immediate recall from WM. These results suggest that fixing temporal parameters of the LoP span task does not moderate the null LoP effect in WM, and further indicate that WM and long-term episodic memory are dissociable on the basis of LoP effects.     

Patterns of memory failure after scopolamine treatment: implications for cholinergic hypotheses of dementia

To test the idea that scopolamine provides a suitable pharmacological model of the memory defects associated with cortical or subcortical dementias, we assessed memory on a battery of tasks in healthy young normal subjects who received 0.5 mg scopolamine, 0.1-0.2 mg glycopyrrolate or physiological saline, once each on three separate occasions, and compared the pattern of memory failure induced by scopolamine to that observed on the same tasks in patients with Alzheimer's disease (AD) or Huntington's disease (HD). In agreement with previous reports, scopolamine impaired acquisition and delayed recall of a 14-word list and disrupted retention on the Brown-Peterson distractor task, whereas the peripherally active anticholinergic glycopyrrolate was without effect. However, under scopolamine the pattern of errors made on these memory tasks was quite different from that seen in patients with AD. Scopolamine did not increase the number of false positive errors on delayed recognition of the word list and also failed to increase the number of prior-item intrusions on the Brown-Peterson task. Also, scopolamine did not impair learning of a symbol-digit paired-associate task, and did not reduce the number of words retrieved or increase the number of words repeated on a standardized verbal fluency test. When the effects of scopolamine on memory were compared to the pattern of impairments observed in demented patients with HD, several differences were found. Although scopolamine clearly produces deficits on some measures of anterograde memory, the present findings question whether anticholinergic drugs adequately mimic the full range of memory impairments observed in cortical or subcortical dementias.