Memory dysfunction in caudate infarction caused by Heubner's recurring artery occlusion

We report five cases with caudate infarction due to Heubner's recurring artery occlusion, in which we conducted detailed memory examinations in terms of explicit memory and implicit memory. We performed the auditory verbal learning test as explicit memory tasks, and motor and cognitive procedural memory tasks, developed by Komori, as implicit memory tasks. Comparing normal control subjects with patients with left caudate infarction due to Heubner's recurring artery occlusion demonstrated lower scores on both declarative and motor procedural memory tasks. These results suggest that the left caudate nucleus may be related with both declarative memory and procedural memory.     

Effects of Level of Processing on Implicit and Explicit Memory in Depressed Mood

Recently, several studies have addressed the question of whether depression affects priming in implicit memory tasks. The main aim of this experiment was to assess the presence of a bias for negative information in explicit memory (free recall) and implicit memory (word-stem completion) tasks among subclinically depressed subjects compared to nondepressed subjects, using the typical levels of processing manipulation. The results of this study show the existence of a mood-congruent memory bias for both implicit and explicit memory in depressed subjects. The theoretical implications of these findings for implicit and explicit memory biases associated with depressed mood are discussed.     

Clinical depression and implicit memory.

We investigated performance on implicit and explicit memory tasks in subjects diagnosed with major depression and matched controls. Depressed subjects showed impaired performance on both the explicit and implicit tasks in comparison with controls. These findings are in contrast to groups such as amnesic patients and older adults, who show preserved abilities on implicit tasks and deficits on explicit tasks.     

Degree of cognitive impairment and the dissociation of implicit and explicit memory

One group of normal elderly adults and two groups of cognitively impaired elderly adults were compared on an implicit and an explicit memory task. Degree of impairment affected explicit memory; the mildly and moderately impaired elderly adults demonstrated significantly reduced recognition performance. Degree of impairment also affected implicit memory priming performance, particularly for low frequency items, as measured by a word completion task. Explicit memory performance declined for both cognitively impaired groups, but implicit memory performance was sensitive to the degree or severity of impairment, causing a decline in performance only in the moderately impaired group.     

智障儿童和正常儿童外显记忆与内隐记忆的比较研究

本实验采取加工分离程序(PDP)对38名弱智儿童的外显记忆与内隐记忆进行研究,并与47名正常儿童进行比较,结果认为:(1)正常儿童外显记忆明显优于弱智儿童,但在内隐记忆方面,正常儿童与弱智儿童没有显著差异;(2)本实验中,年龄对内隐记忆和外显记忆均没有影响。研究结果对弱智儿童的教育方面有启示作用;另外,PDP实验由于其本身的复杂性,在对特殊人群进行施测时,需要特别注意。     

Aging affects word-stem completion and recognition but not category generation

In this study, we investigated the effect of aging on two implicit memory tasks, word-stem completion and category generation, and on explicit recognition. We compared the performance of young and older adults on these implicit memory tasks with those of explicit recognition. We expected better performance of young than older adults in the explicit memory task and similar priming in both implicit memory tasks. The results showed that young adults performed better than older adults in the recognition task. Moreover, both age groups showed priming in the implicit memory tasks, although priming was greater in young adults compared to older adults in the word-stem completion memory task, whereas both age groups showed similar levels of priming in the category generation task. The present results showed dissociations as a function of age not only between the explicit and the implicit tasks but also between the implicit tasks.     

Memory training interventions require a tailor-made approach: Commentary on McDaniel and Bugg

Memory training for older adults often produces gains that are limited to the particular memory tasks encountered during training. We suggest that memory training programs may be misguided by an implicit "generalist" assumption-memory training on a couple of memory tasks will have a positive benefit on memory ability in general. One approach to increase memory-training benefits is to target training for the everyday memory tasks for which older adults struggle. Examples include training retrieval strategies, prospective memory strategies, and strategies for learning and remembering names. Another approach is to design training to foster transfer. Possible elements to improve transfer are increasing the variation that is experienced during the course of training at the level of stimuli and tasks, incorporating "homework" that guides the older adult to become attuned to situations in which the strategies can be applied, and providing older adults with a better understanding of how memory works. Finally, incorporating aerobic exercise into memory training programs may potentiate the acquisition and maintenance of the trained cognitive strategies.     

A Developmental Trajectory in Implicit Memory is Revealed by Picture Fragment Completion

Dissociations between performance on implicit and explicit tasks have often been taken as evidence that different neural structures subserve the two types of memory. One such dissociation involves developmental differences that emerge in explicit tasks, but which appear to be absent in implicit tasks. Such findings are consistent with the idea that implicit memory is subserved by a more primitive system that evolves earlier at both phylogenetic and ontogenetic levels. The present paper reviews previous studies that claimed to find evidence that implicit memory is fully developed in very young children. Issues of measurement error, ceiling effects, and insufficient power brought up questions about those studies with respect to the developmental issue. The present study compares performance on implicit (picture fragment completion) and explicit (free recall and recognition) memory tasks with groups ranging in age from 5–28 years. We find a reliable developmental trend in both implicit and explicit performance in which the former cannot be attributed to the operation ofexplicit memory processes. Thus, we conclude that implicit memory, like explicit memory, develops with age.     

Memory for things forgotten.

As previous research has shown, items not recalled on an initial memory task are not simply forgotten. Often, some can be recalled on a later, second task. Further, subjects can generally predict, in terms of feeling-of-knowing (FOK) ratings, which items will be subsequently recalled. Two experiments were carried out to assess both second-task performance and FOK accuracy for unrecalled items as a function of two factors, encoding manipulations (levels of processing in Experiment 1, study time in Experiment 2) and the nature of the second task (explicit or implicit cued stem completion). Results indicate that although levels of processing affected explicit second-task performance more than implicit second-task performance, it increased FOK accuracy in both types of tasks. Study time, however, affected FOK accuracy only in the explicit second task. Apparently, only when subjects were able to do some elaborative processing on the items did their FOK ratings reflect information relating to factors that drive performance on implicit tasks.     

Adult age differences in implicit and explicit memory: time course and encoding effects

Young and older adults were tested at three delays on word-stem completion or cued recall following semantic or structural word judgments. Identical three-letter stems were present at retrieval for both implicit (completion) and explicit (cued recall) tasks; only the intention to recall list words differed. The young adults outperformed the older adults on both implicit and explicit tasks at all test delays. Under some conditions, the older but not the young adults performed more poorly on cued recall than on stem completion, suggesting a possible failure to use implicitly available information to support explicit remembering. These results suggest that some forms of implicit memory decline with normal aging.     

Explicit and implicit memory in dementia and normal ageing

Summary In two experiments, young subjects, healthy elderly subjects (spouses), and highly intelligent elderly subjects (elite elderly), were compared with dementia patients in a variety of explicit and implicit memory tasks, to investigate two issues: whether priming in Alzheimer-type dementia is contingent upon the presence of pre-existing representations, and whether intelligence modulates performance in explicit memory tasks in healthy ageing. Dementia patients performed as well as spouses in a homophone-spelling task. Moreover, they established new contextual associations when memory was tested by word-stem completion. The hypothesis that priming in dementia is contingent upon pre-existing memory representations was not supported. Spouses, elite elderly, and young subjects did not differ in their ability to recognize correctly recently heard stimuli or to complete word stems. However, recall of lists of words and paired associates was better in both young and elite elderly subjects than in spouses. It is concluded that intellectual capacity rather than chronological age in healthy subjects modulates performance in explicit-memory tasks.Now at The Social Psychiatry Unit, Australian National University, Canberra, ACT, Australia     

视障群体的编码方式对动作内隐和外显记忆影响的实验研究

采用加工分离程序的研究方法,以视障运动员和视障学生为实验组,明眼运动员和明眼学生为对照组,以肘关节动作为实验材料,考查了动作内隐和外显记忆的特点。结果显示：(1)视障和明眼运动员的动作内隐和外显记忆均受到编码方式的影响;而视障和明眼学生仅动作外显记忆受到编码方式的影响：(2)不同被试类间的动作内隐和外显记忆成绩存在差异。     

增龄性记忆改变规律及影响因素的研究

本研究用多维记忆量表对280名50～91岁的老年人做了测查,同时收集了一般资料,以探讨增龄性记忆改变的规律和年龄、教育和职业等因素对增龄性记忆改变的影响。结果表明：随年龄增长,各记忆组合分和分测验成绩均呈下降趋势,外显记忆成绩在70岁后呈快速下降,内隐记忆和日常生活记忆在75岁后才有明显下降;记忆总分、外显记忆和日常生活记忆均受年龄和教育的影响,内隐记忆不受教育的影响。结果提示老年人记忆随年龄增长呈渐渐下降,不同记忆功能开始下降的年龄和下降速率不同,教育对增龄性记忆改变有保护作用。     

聋童和正常儿童在内隐和外显记忆上的发展差异

本研究采用自行编制计算机化的加工分离程序(PDP)．旨在探讨聋童和正常儿童是否在内隐和外显记忆上存在不同的发展模式。结果显示：(1)人群和年龄对内隐记忆没有显著影响,而外显记忆存在显著的人群差异和年龄差异;(2)外显记忆的人群和年龄存在显著的交互作用,聋童随年龄增长,其外显记忆存在显著的发展,而正常儿童的外显记忆有略微的下降。本研究结果支持意识和无意识的权衡理论．并为聋童教育提供了一些启示。     

Collaboration and Memory: Effects of Dyadic Retrieval on Different Memory Tasks

Collaborative retrieval was investigated in two experiments. The experiments were explicitly designed to investigate how different types of memory tasks were affected by two individuals working together compared to individuals working on their own. A nominal group score was treated as the predicted potential a dyad could attain. In Experiment 1, semantic and episodic retrieval were employed. The episodic task was to encode and retrieve a story and the semantic task was to answer, without any encoding, 20 questions from the same history domain as the episodic task. In Experiment 2, explicit recognition and implicit retrieval of dot patterns were employed. The explicit recognition task was forced-choice, and in the implicit task, subjects were instructed to complete a pattern they saw from an incomplete pattern. The results suggest that: (1) dyads suffer from collaboration relative to the predicted potential, (2) the reduction of productivity for dyads was limited to explicit and episodic memory tasks, and (3) friends as opposed to non-friends reduced the negative effect of collaboration. The results replicate and extend the results from a previous study.     

Input- and output-monitoring in implicit and explicit memory

Previous experiments have shown that the procedure of questioning subjects retrospectively about the input and output status of information (input and output monitoring) is a useful method for assessing the awareness states of subjects during implicit and explicit memory tasks. The main purpose of the present study was to investigate whether the previous findings could be extended to other implicit and explicit memory tasks. We were especially interested in whether differences in input- and output-monitoring performance can be observed when both the implicit and explicit memory tasks are conceptual ones. In a final test phase, the target items from the study phase and new distractor items were presented. In a recognition-like situation, subjects had to decide whether an item had been presented in the study phase (input status), as well as whether they had produced the item in the memory-test phase (output status). In all three experiments judgments about the input status - but only for those items that had been produced in the implicit or in the explicit memory test - were more precise after explicit than after implicit memory testings. This finding was not influenced by the distinction between perceptual and conceptual-memory tasks (Exp. 1), and was obtained under conditions in which the implicit and the explicit memory tasks were both conceptual and differed only in test instructions (Exps. 2 and 3). These results suggest that not only subjects performing a perceptual test of implicit memory, but also subjects in a conceptual implicit test were less aware of using information from a previous study episode than subjects who received memory instructions. It is concluded that requiring judgments about the input status of information is a good method for assessing subjects test awareness and is preferable to the use of a questionnaire (Exp. 3). In contrast, in all three experiments no differences were found with the output-monitoring measure between implicit and explicit test conditions.     

Near‐ and Far‐Transfer Effects of Working Memory Updating Training in Elderly Adults

Age‐related declines in working memory, especially with regard to updating ability, affect many high‐level aspects of cognition in elderly adults. Recent studies have demonstrated that training might improve working memory. We investigated the effects of 20 days of adaptive training of working memory updating in healthy elderly adults. Comparing the performance on cognitive function tests before and after training in a trained group and a non‐trained group, significant positive training effects were observed in a numerical updating task and a digit‐span test, but not in a non‐verbal reasoning test. The results suggest beneficial effects of working memory updating training to working memory tasks that use different content material and task formats than those used during training. However, confirming the results of previous studies, transfer effects to other higher order cognitive processes seem to be absent in elderly adults. Copyright © 2014 John Wiley & Sons, Ltd.     

Correlational analyses of explicit and implicit memory performance

Sixty-four subjects were administered two tests of explicit memory (selective recall and recognition) and four tests of implicit memory (identification in a perceptual clarification procedure, word-fragment completion, tachistoscopic identification, and anagram solution). Each test drew on a different subset of a long list of previously displayed words. Although the four implicit memory tests showed sizable priming effects, correlational and factor analyses showed striking dissociations. On the one hand, performance on the perceptual clarification procedure and word-completion tests were related to one another, as well as to recall and recognition. On the other hand, performance on tachistoscopic identification and anagram solution were related to one another, but not to the measures for the other tasks. A framework is proposed to reconcile these new results with current knowledge on the explicit/implicit memory distinction, based in particular on studies of amnesic subjects. It is argued that a small number of tasks, especially tachistoscopic identification, may serve as relatively uncontaminated and ubiquitous indicators of implicit memory. However, explicit remembering could affect performance in so-called implicit memory tasks that allow for a strategy of controlled selection of candidate responses from accumulating cues, in experimental conditions that make the explicit remembering of relevant events possible.     

Examining the Response Competition Hypothesis of Age Effects in Implicit Memory

ABSTRACT

Age reductions in priming have been explained by differences in processing demands across implicit memory tests. According to one hypothesis, older adults show reduced priming relative to younger adults on implicit tests that require production of a response because these tests typically allow for response competition. In contrast, older adults do not show reductions in priming on identification tests that contain little response competition. The following experiments tested the specific role of response competition in mediating age effects in implicit memory. In Experiment 1, younger and older adults studied a list of words and were then given an implicit test of word stem completion. They studied a second list of words and were given an implicit test of general knowledge. Each implicit test contained items with unique solutions (the low response competition condition) and items with multiple solutions (the high response competition condition). In Experiment 2, younger and older adults were given explicit versions of the word stem completion and the general knowledge tests. Results showed an effect of age on explicit memory (Experiment 2), but no effect of age or response competition on priming (Experiment 1). Results are inconsistent with the theory that response competition leads to age effects on production tests of implicit memory.     

认知疲劳效应对内隐记忆与外显记忆的影响

本研究通过比较内隐记忆与外显记忆受到认知疲劳影响的情况,以了解内隐记忆的自动化加工机制。实验采用被试内设计,使用词汇判断与词汇再认任务测量内隐记忆与外显记忆。实验结果发现,相对于控制组,疲劳组的被试在完成疲劳任务后内隐记忆成绩显著下降,而外显记忆没有受到影响。结果说明相对于外显记忆,内隐记忆更容易受到认知疲劳影响。内隐记忆虽然是无意识的认知加工,但是与其他自动化加工具有不同的特征。