高难度材料的元记忆监测更受记忆广度的制约

以不同难度(有、无意义联系)的两种中文词对为记忆材料,随机选取在校大学生200名,采用经典的回忆-判断-再认(recall-judgement-recognition,RJR)范式,考察短时记忆广度和一般自我效能感对个体在不同难度材料上元记忆监测的影响。结果发现,相比于无意义联系的材料,个体在有意义联系的材料上,JOL、FOK和JOC判断等级更高,线索回忆测验成绩更好。但是,个体在不同材料上的JOL判断和线索回忆受短时记忆广度的调节。不同短时记忆广度的个体在有意义联系材料上的JOL判断等级和线索回忆测验成绩无显著差异,但是在无意义联系材料上,高短时记忆广度个体的JOL判断等级和线索回忆测验成绩均显著高于低短时记忆广度个体。同时,相关分析结果也发现,相比于低短时记忆广度的个体,高短时记忆广度的个体,其线索回忆测验成绩和再认测验成绩与JOL、FOK和JOC判断等级之间更加相关。实验结果表明,作为一种人格变量,一般自我效能感对个体元记忆监测的影响可能并不明显。而短时记忆广度,很大程度上反映了个体的记忆能力,是个体元记忆监测的一个重要影响因素,尤其是对难度较大的材料。     

短时记忆范畴效应的实验研究

本实验用Sternberg 的变化字表法以汉言双字词为材料研究短时记忆中单范畴字表与双范畴字表的信息提取。结果为,无论有无策略要求均未发现双范畴字表提取的反应时小于单范畴字表的范畴效应。但双范畴字表的准确率均高于单范畴字表。这种结果与文献所载结果不同。作者提出短时记忆的范畴效应不仅可表现在信息提取的反应时上,也可表现在提取的准确率上,并讨论了产生这种效应的原因。     

自由回忆中元记忆监控的作用及其影响因素

采用“类信号检测论方法”,通过两个实验,研究了在记忆信息提取过程中元记忆的预见性监测判断（Feeling-of-knowing）和元控制的作用及其影响因素。实验一探讨了识记材料的难易、识记遍数对元监测判断以及输出控制中的反应标准是否有影响;实验二探讨了严格和宽松的奖惩条件对输出控制中反应标准的影响。用计算机随机呈现识记用的词表材料,识记之后让被试进行FOK等级判断和自由回忆,再用“类信号检测论”方法统计实验数据,分析各种条件下回忆成绩、FOK判断等级,计算出相应的符合率和反应标准。实验一结果表明,不同材料难度和识记遍数下的回忆成绩和FOK判断等级差异显著,但输出控制中的反应标准值没受这些因素的影响;实验二结果是严格和宽松奖惩条件下的反应标准值差异显著,严格条件下的反应标准显著高于宽松条件下的反应标准,表明奖惩条件对信息提取中的反应标准有显著影响     

延迟学习判断的效应机制

研究考察了延迟学习判断的记忆假说和元记忆假说。实验一通过插入预测试的方法, 消除即时学习判断与延迟学习判断在记忆方面的差异, 结果发现, 延迟学习判断的准确性显著高于插入预测试的即时学习判断的准确性, 说明延迟学习判断的确提高了元记忆水平; 实验二采用PRAM实验程序, 对元记忆假说的机制进行探讨, 结果发现, 加入干扰任务的即时学习判断排除短时记忆的程度远远低于延迟学习判断干扰, 说明学习判断的准确性与短时记忆干扰的排除程度有关, 短时记忆干扰越强, 学习判断的准确性 越低。     

编码方式对汉字短时记忆提取的影响

短时记忆提取是认知心理学研究中的重要课题之一。自Sternberg(1 966)提出短时记忆提取作的是序列的从头到尾的完全搜索以来 ,许多研究者对短时记忆提取进行了广泛的研究 ,提出了序列的自动停止的搜索、平行加工、直接存取 ,以及序列搜索和直接存取双重模型等许多不同看法 ,引起了激烈争论。本研究的目的是试图探索编码方式对汉字短时记忆提取的影响。实验运用Sternberg的“探测法” ,以随机排列的汉字作识记组和探测项刺激。实验结果表明 :编码方式对汉字短时记忆提取有很大影响 ,当用声音编码方式提取短时记忆汉字时 ,被试倾向于从头到尾的完全的搜索 ;当用形状编码时 ,被试倾向于作自动停止的搜索。     

双任务并存条件下的信息提取

将短时记忆再认与长时记忆范畴判断两类不同性质的信息提取任务相并列,探讨了双任务条件下的信息提取过程是如何进行的。实验结果表明,双任务并存时,ｎｏ反应的总平均反应时不等于两种任务单独进行时各自ｎｏ反应的平均反应时之和（减去一次视觉动作反应时后）,而是与其中一个较后完成的过程的ｎｏ反应平均反应时相近。因此推断双任务并存时,信息提取过程不是完成一个再进行另一个的系列加工过程,而是二者同时平行加工的过程。     

视觉长时记忆激活度对促进视觉短时记忆的影响

短时记忆与长时记忆的关系是记忆领域研究的重要内容。基于此, 研究者们就视觉长时记忆是否能促进视觉短时记忆的问题展开了大量研究, 但所得出的结论并不一致。通过不同程度的学习形成不同激活度的视觉长时记忆, 考察对几何图形的视觉长时记忆是否能对变化检测中的短时记忆起到促进作用。结果发现, 低激活水平的视觉长时记忆不能促进视觉短时记忆, 而事先存在且高度激活的视觉长时记忆对视觉短时记忆却具有促进作用; 同时, 随着视觉长时记忆激活水平的提高, 刺激间间隔的效应值也逐渐减小。本研究说明, 视觉长时记忆能否促进视觉短时记忆取决于视觉长时记忆的激活水平, 高激活的视觉长时记忆对阻止视觉短时记忆痕迹的迅速消退具有重要意义。     

无关言语对汉字短时记忆系列回忆的影响*

采用视觉呈现字表和听觉呈现无关言语方式,探讨在字表项目保持期间阻止被试复述情况下,不同呈现位置的无关言语对汉字短时记忆系列回忆的影响。在字表保持期间,采用计算任务进行分心作业。实验结果发现：(1)无关言语对汉字短时记忆系列回忆成绩存在显著影响;(2)在字表保持期间阻止被试进行复述消除了字表呈现期间呈现无关言语对回忆成绩产生的干扰效应;(3)汉字短时记忆系列回忆成绩表现出系列位置效应。实验结果没有完全支持客体情节记忆模型。     

短时记忆研究的新进展

人们对短时记忆的研究最早可以追溯到Ebbinghaus。他在记忆研究中采用无意义音节作为实验材料,发现读一遍能够记住的音节数是七个,这一结果成为广为人知的短时记忆的容量。后来人们发现,短时记忆的容量与很多复杂认知活动有关,这使得研究者更加关注短时记忆。20世纪五、六十年代,主要研究记忆广度、短时记忆与长时记忆的区分,全部报告法、分散注意法是当时的主要研究方法。     

视觉感觉记忆信息在模式识别中的作用

该研究设计了新的实验方法进行了两项全部报告实验和两项抽样模式识别实验,考察视觉感觉记忆(visual sensorymemory,VSM)信息在模式识别中的作用。结果发现,在限定利用短时记忆(shor-term memory,STM)信息的抽样模式识别作业中,识别出的模式与转换到短时记忆的模式在数量上无显著性差别,而在短时记忆和感觉记忆信息都可能利用的识别作业中,虽然转换到短时记忆的模式数量并未增加,但识别出的模式比转换到短时记忆的模式数量增加了1倍(P<0.001)。这表明,未能转换到短时记忆的感觉记忆信息可被直接用于模式识别。     

Temporal interval production and short-term memory

Interference with time estimation from concurrent nontemporal processing has been shown to depend on the short-term memory requirements of the concurrent task (Fortin & Breton, 1995; Fortin, Rousseau, Bourque, & Kirouac, 1993). In particular, it has been claimed that active processing of information in short-term memory produces interference, whereas simply maintaining information does not. Here, four experiments are reported in which subjects were trained to produce a 2,500-msec interval and then perform concurrent memory tasks. Interference with timing was demonstrated for concurrent memory tasks involving only maintenance. In one experiment, increasing set size in a pitch memory task systematically lengthened temporal production. Two further experiments suggested that this was due to a specific interaction between the short-term memory requirements of the pitch task and those of temporal production. In the final experiment, subjects performed temporal production while concurrently remembering the durations of a set of tones. Interference with interval production was comparable to that produced by the pitch memory task. Results are discussed in terms of a pacemaker-counter model of temporal processing, in which the counter component is supported by short-term memory.     

Capacity limitation in short-term visual memory for contour curvature

I measured the difference threshold for contour curvature in short-term visual memory (STVM) using a two-interval forced-choice partial discrimination task. In experiments 1 and 2, the study stimulus consisting of 1 to 4 curved contours was briefly presented. It was followed by a single contour stimulus after a retention interval. The subjects judged if the test stimulus had a higher or lower curvature than the corresponding study contour. The results of experiment 1 showed that the Weber fraction increased monotonically with increasing set size. The results of experiment 2 clarified that the set-size effect was not due to a temporal limitation in encoding resulting from the short exposure time. In experiment 3, the study stimuli always consisted of 4 items, but the numbers of memorised items were different in each condition. Nevertheless, the results showed the set-size effect, which indicated that its occurrence depended largely on the capacity limitation in short-term visual memory (STVM) storage. Otherwise, the Weber fraction was not hugely higher for set size 4 compared with set size 1. It was concluded that only 1 object could be retained in STVM with high fidelity, but that at least 4 objects could be retained in STVM with some degree of fidelity.     

Processing of formational, semantic, and iconic information in American sign language

Three experiments examined short-term encoding processes of deaf signers for different aspects of signs from American Sign Language. Experiment 1 compared short-term memory for lists of formationally similar signs with memory for matched lists of random signs. Just as acoustic similarity of words interferes with short-term memory or word sequences, formational similarity of signs had a marked debilitating effect on the ordered recall of sequences of signs. Experiment 2 evaluated the effects of the semantic similarity of the signs on short-term memory: Semantic similarity had no significant effect on short-term ordered recall of sequences of signs. Experiment 3 studied the role that the iconic (representational) value of signs played in short-term memory. Iconicity also had no reliable effect on short-term recall. These results provide support for the position that deaf signers code signs from American Sign Language at one level in terms of linguistically significant formational parameters. The semantic and iconic information of signs, however, seems to have little effect on short-term memory.     

Effects of word frequency and age of acquisition on short-term memory span

The experiments reported examine the effects of two highly related variables, word frequency and age of acquisition, on short-term memory span. Short-term memory span and speech rate were measured for sets of words which independently manipulated frequency and age of acquisition. It was found that frequency had a considerable effect on short-term memory span, which was not mediated by speech rate differences—although frequency did affect speech rate in one experiment. For age of acquisition, this situation was reversed; there was a small but significant effect of age of acquisition on speech rate, but no effect on memory span. This occurred despite results confirming that the stimuli used in the experiments produce an effect of age of acquisition on word naming. The results are discussed in terms of a two-component view of performance on short-term memory tasks.     

Retrieval of information from multiple ensembles in short-term memory

A recognition memory experiment investigated Ss’ ability to organize information in short-term memory. A paradigm similar to that used by Sternberg was employed. A sequentially presented series of six digits (positive set) was shown with each digit appearing on a red, green, or amber background. The colors defined different ensembles, and responding to a test digit was contingent upon an item’s membership in the positive set and the color-defined ensemble. Reaction time (RT) to the test digits indicated that Ss did organize information into ensembles. Furthermore, when informative cues were presented prior to the test item, Ss directed and confined their search to the cued subset.     

Reduced short-term memory capacity in Alzheimer's disease: the role of phonological, lexical, and semantic processing

Individuals with Alzheimer's disease (AD) are often reported to have reduced verbal short-term memory capacity, typically attributed to their attention/executive deficits. However, these individuals also tend to show progressive impairment of semantic, lexical, and phonological processing which may underlie their low short-term memory capacity. The goals of this study were to assess the contribution of each level of representation (phonological, lexical, and semantic) to immediate serial recall performance in 18 individuals with AD, and to examine how these linguistic effects on short-term memory were modulated by their reduced capacity to manipulate information in short-term memory associated with executive dysfunction. Results showed that individuals with AD had difficulty recalling items that relied on phonological representations, which led to increased lexicality effects relative to the control group. This finding suggests that patients have a greater reliance on lexical/semantic information than controls, possibly to make up for deficits in retention and processing of phonological material. This lexical/semantic effect was not found to be significantly correlated with patients' capacity to manipulate verbal material in short-term memory, indicating that language processing and executive deficits may independently contribute to reducing verbal short-term memory capacity in AD.     

Short-term memory across eye blinks

The effect of eye blinks on short-term memory was examined in two experiments. On each trial, participants viewed an initial display of coloured, oriented lines, then after a retention interval they viewed a test display that was either identical or different by one feature. Participants kept their eyes open throughout the retention interval on some blocks of trials, whereas on others they made a single eye blink. Accuracy was measured as a function of the number of items in the display to determine the capacity of short-term memory on blink and no-blink trials. In separate blocks of trials participants were instructed to remember colour only, orientation only, or both colour and orientation. Eye blinks reduced short-term memory capacity by approximately 0.6–0.8 items for both feature and conjunction stimuli. A third, control, experiment showed that a button press during the retention interval had no effect on short-term memory capacity, indicating that the effect of an eye blink was not due to general motoric dual-task interference. Eye blinks might instead reduce short-term memory capacity by interfering with attention-based rehearsal processes.     

Similarity as an organising principle in short-term memory

Abstract

The role of stimulus similarity as an organising principle in short-term memory was explored in a series of seven experiments. Each experiment involved the presentation of a short sequence of items that were drawn from two distinct physical classes and arranged such that item class changed after every second item. Following presentation, one item was re-presented as a probe for the ‘target’ item that had directly followed it in the sequence. Memory for the sequence was considered organised by class if probability of recall was higher when the probe and target were from the same class than when they were from different classes. Such organisation was found when one class was auditory and the other was visual (spoken vs. written words, and sounds vs. pictures). It was also found when both classes were auditory (words spoken in a male voice vs. words spoken in a female voice) and when both classes were visual (digits shown in one location vs. digits shown in another). It is concluded that short-term memory can be organised on the basis of sensory modality and on the basis of certain features within both the auditory and visual modalities.     

A deficit in the short-term retention of lexical-semantic information: forgetting words but remembering a story

This article examines the long-term memory of a patient, AB, who had previously been reported to have problems in the short-term retention of word meanings. The authors found that AB had a problem not only in the short-term but also in the long-term retention of lexical-semantic information. AB, however, had no problem in the long-term retention of other kinds of information (pictures, shapes, propositional information). This pattern of results was interpreted as evidence that lexical-semantic representations have their own specific memory resources that are involved in the retention of the corresponding representations across different time intervals (e.g., they are involved in short-term as well as long-term retention). Implications for models of memory are discussed.     

Order information in short-term memory and time estimation

In previous experiments, the amount of interference between time production and visual or memory search tasks was shown not to be related to the level of difficulty of the search task per se, but instead to the amount of processing in short-term memory required in the search task. The first experiment of the present study verified whether the amount of interference between time production and a short-term memory task may be related to the level of difficulty of the short-term memory task. Two versions of a memory task, with and without processing of order information, were combined with a temporal interval production task in a concurrent processing condition. As is shown in a control reaction time task, processing order information increased the level of difficulty of the memory search task. In the concurrent processing condition, the interference between short-term memory processing and time production was stronger when the level of difficulty of the short-term memory search task was increased by requiring that order information be processed. The results of Experiment 2 showed that the amount of interference between a similar short-term memory task and time production seems not to be related to the amount of order information that must be maintained during the time production task. This dissociation between the effects of processing and the maintenance of order information is compatible with a similar dissociation, observed in previous experiments, between the effects of processing and those of maintaining item information in short-term memory on concurrent time production.