Memory impairment following ruptured aneurysm of the anterior communicating artery

This study reports the case of a 42-year-old man who suffered a ruptured aneurysm of the anterior communicating artery. His memory capabilities were assessed after a considerable recovery period during which many of his memory deficits ameliorated. His scan revealed a left frontal lesion and many of his deficits were characteristic of frontal impairment. He was impaired on temporal discrimination, and he showed marked source forgetting. He also performed badly on the Brown-Peterson task, and we suggest that this is another task that may be characteristic of frontal impairment. In contrast, the patient showed normal or near normal performance on some memory tasks but not on others. It is concluded that the patient's frontal signs are similar to those found in Korsakoff's Syndrome, but that his memory impairment is qualitatively different from that encountered in patients with the amnesic syndrome.     

Rehabilitation of executive deficits in closed head injury and anterior communicating artery aneurysm patients

This paper reports a study that was aimed to rehabilitate executive functions in closed head injury (CHI) and anterior communicating artery (ACoA) aneurysm patients. The groups tested comprised 10 CHI patients, 9 ACoA aneurysm patients and 19 controls. We employed a dual-task paradigm that is known to tap the ability to co-ordinate two actions. The treatment consisted of five experimental sessions, in which the dual-task paradigm was used. In the CHI study, the dual-task cost was measured before the treatment (assessment), immediately after the treatment (retest), and 3 months after the treatment (follow-up). In the ACoA aneurysm study, the dual-task cost was also assessed 12 months after the treatment. A significant reduction of the dual-task cost from assessment to retest was found. This reduction remained stable in the follow-up sessions. The results are discussed with reference to the absence of spontaneous recovery of this specific executive function and to the possibility that the beneficial effect of the treatment generalises to other executive functions and/or daily living activities. Received: 31 March 1999 / Accepted: 23 July 1999     

Cognitive processes supporting episodic memory formation in childhood: The role of source memory,binding, and executive functioning

Episodic memories contain various forms of contextual detail (e.g., perceptual, emotional, cognitive details) that need to become integrated. Each of these contextual features can be used to attribute a memory episode to its source, or origin of information. Memory for source information is one critical component in the formation of episodic memories. Likewise, the establishment of episodic memories also requires binding, which reflects the process of encoding the relations among stimuli and provides the experience that certain features of a memory episode belong together. The aims of the present review are to explore the roles of (1) cognitive and neural mechanisms involved in source memory and binding and how the development of these cognitive processes relates to episodic memory formation in childhood and (2) other higher-order cognitive processes, namely executive functioning, in early episodic memory development. We conclude by examining the challenges within this field of research, highlighting the role of other cognitive processes (e.g., sense of self, language, use of strategies) that may contribute to episodic memory formation, addressing areas that can be improved with additional research, and exploring directions for future work.     

Lack of awareness of neuropsychological deficit in cerebral small vessel disease: The relationship with executive and episodic memory functions

A common cause of neuropsychological impairment in older adults is cerebral small vessel disease (SVD), but little is known as to whether lack of awareness of neuropsychological impairment is a feature of this clinical condition. In this study, we investigated awareness deficits in a well‐phenotyped population of patients with SVD (n= 45; 21 with defined concomitant neuropsychological impairment) and made comparisons with 24 Alzheimer's disease (AD) patients and a further 80 control participants. Awareness of performance on a range of neuropsychological measures was examined based on the Brief Memory and Executive Test Battery (BMET) (Brookes, Hannesdottir, Lawrence, Morris, & Markus, 2012 ), exploring the relationship between awareness and memory and executive function. The results revealed significant awareness deficits in both the SVD and AD groups. When splitting the SVD group into those with or without concomitant neuropsychological impairment, only those with neuropsychological impairment showed reduced awareness. For the SVD group, executive function was significantly correlated with awareness but memory was not. By comparison, memory was significantly correlated with awareness in the AD group, with executive function showing a trend but remaining non‐significant. The results show that lack of awareness of deficit is a clinical feature of SVD and indicate that there are distinct neuropsychological associations with awareness deficit for SVD and AD.     

Deconstructing the effect of self-directed study on episodic memory

Self-directed learning is often associated with better long-term memory retention; however, the mechanisms that underlie this advantage remain poorly understood. This series of experiments was designed to “deconstruct” the notion of self-directed learning, in order to better identify the factors most responsible for these improvements to memory. In particular, we isolated the memory advantage that comes from controlling the content of study episodes from the advantage that comes from controlling the timing of those episodes. Across four experiments, self-directed learning significantly enhanced recognition memory, relative to passive observation. However, the advantage for self-directed learning was found to be present even under extremely minimal conditions of volitional control (simply pressing a button when a participant was ready to advance to the next item). Our results suggest that improvements to memory following self-directed encoding may be related to the ability to coordinate stimulus presentation with the learner’s current preparatory or attentional state, and they highlight the need to consider the range of cognitive control processes involved in and influenced by self-directed study.     

Sex differences in the correlation of memory span with scan and other episodic memory tasks

Three studies of the relationship between memory span and other measures of memory and information processing are reported here. These other measures included memory scanning rate, the short- and long-term components of free recall, and word recognition from long-term memory. All three studies produced evidence for a sex difference in the correlation of these tasks with memory span. The first study produced a partial replication of Chiang and Atkinson's report (Memory & Cognition, 1976, 4,661–667) of a sex difference: for males, span and scanning rate were unrelated, while for females they were positively correlated. The second study showed that span and the primary memory component of free recall had a modest positive correlation for females but not for males, while span was unrelated to measures of secondary or long-term memory for females but was consistently positively related for males. In the third study, recognition accuracy and span were uncorrelated for females, but positively correlated for males. Finally, a reanalysis of data from a large-scale study by Underwood, Baruch, and Malmi (Journal of Experimental Psychology: General, 1978, 107, 393–419) also showed evidence of similar sex differences. Sex differences involving the correlation of memory span with other cognitive test performances seem quite general and need to be taken account of in the analyses of individual differences in memory and cognitive processes. A tentative theory is presented to account for the differences found in these studies.     

Simulating episodic memory deficits in semantic dementia with the TraceLink model

Although semantic dementia is primarily characterised by deficits in semantic memory, episodic memory is also impaired. Patients show poor recall of old autobiographical and semantic memories, with better retrieval of recent experiences; they can form new memories, and normal performance on pictorial recognition memory has been demonstrated. As these abnormalities in episodic memory are virtually a mirror image of those seen in the amnesic syndromes, semantic dementia poses a challenge to extant models of remote memory and amnesia. Here, we show that one such model, TraceLink, can reproduce some of the principal findings on episodic memory in semantic dementia. A loss of nodes and connections within the trace system, which can be identified with the temporal neocortical memory storage sites implicated in semantic dementia, simulates without further assumptions the findings reported above.     

Simulating episodic memory deficits in semantic dementia with the TraceLink model

Although semantic dementia is primarily characterised by deficits in semantic memory, episodic memory is also impaired. Patients show poor recall of old autobiographical and semantic memories, with better retrieval of recent experiences; they can form new memories, and normal performance on pictorial recognition memory has been demonstrated. As these abnormalities in episodic memory are virtually a mirror image of those seen in the amnesic syndromes, semantic dementia poses a challenge to extant models of remote memory and amnesia. Here, we show that one such model, TraceLink, can reproduce some of the principal findings on episodic memory in semantic dementia. A loss of nodes and connections within the trace system, which can be identified with the temporal neocortical memory storage sites implicated in semantic dementia, simulates without further assumptions the findings reported above.     

Aggregation in memory of episodic influences on rule-guided decisions

The authors confirmed E. Z. Rothkopf and M. L. Dashen's (1995) finding that specific problem context, such as thematic surface features, forms associative connections with deep problem features and thus speeds particular decisions (particularization). In 5 experiments, using a 3-bit decision task and pre-memorized decision rules, the authors found that the ability of a situational context to reinstate was decreased by its replacement by another modal surface context. Context reinstatement, as measured by decision speed, depended on both global and recent local densities of specific problem features linked to a particular decision. The authors' results are consistent with J. R. Anderson and L. J. Schooler's (1991) needs/odds analysis and suggest a push-down file model for diverse context influences as a mechanism for responding to changing situational demands.     

Everyday‐like memory for objects in ageing and Alzheimer's disease assessed in a visually complex environment: The role of executive functioning and episodic memory

To investigate everyday memory, more and more studies rely on virtual‐reality applications to bridge the gap between in situ approaches and laboratory settings. In this vein, the present study was designed to assess everyday‐like memory from the virtual reality‐based Human Object Memory for Everyday Scenes (HOMES) test (Sauzéon et al., 2012 , Exp. Psychol., 59, 99) in ageing and in Alzheimer's disease (AD). Two aims motivated this study: the first was to assess multiple processes of episodic memory (EM) functioning embedded within contexts closely related to real life in ageing and AD using the multi‐trial free‐recall paradigm, and the second aim was to evaluate the mediating effects of executive functioning (EF), EM, and subjective memory complaints (SMCs) on age differences in the HOMES measures and in AD. To this end, the HOMES test and neurocognitive tests of EF and EM were administered to 23 younger adults, 23 older adults, and 16 patients with AD. The results were: firstly, compared to young adults, elderly adults presented only free‐recall decline that almost disappeared in recognition condition whereas AD patients exhibited a poor clustering, learning, and recognition performance, and also a high amount of false recognition; secondly, age differences as well as AD related deficits on the HOMES test were mediated by both memory and EF measure while those observed on false memory indices were only mediated by EM measure; thirdly, the HOMES indices are related to SMCs even when episodic or EF measures are controlled. Overall, the results supported the fact that the VR‐based memory test is an appropriate device to capture age‐related differences as well as the AD effect with respect to both in situ and laboratory settings.     

Contextual information influences the feeling of knowing in episodic memory

The feeling of knowing (FOK) predicts the likelihood of eventually recognizing currently unrecalled items. Koriat (1993, 1995) showed that retrieval of partial target information influences FOK ratings. Building on Koriat’s view, the noncriterial-recollection hypothesis contends that contextual information influences FOKs (Brewer, Marsh, Clark-Foos, & Meeks, 2010). Our study assessed the validity of the noncriterial-recollection hypothesis by controlling the amount of potentially-retrievable contextual information presented to participants. We varied the amount of contextual information accompanying the name and image of imaginary animals. There were three information conditions: minimum (name and image), medium (name, image, and country), and maximum (name, image, country, diet and weight). Information condition did not affect recall accuracy. The minimum condition resulted in greater response output (recall and commission errors together). FOKs for unrecalled items were lower in the minimum condition than the other conditions. Consistent with the noncriterial-recollection hypothesis, FOKs were positively correlated with the retrieval of contextual information.     

物体颜色对情景记忆的影响

本研究采用ERP技术和学习-再认范式考察视觉输入的颜色和记忆中的物体颜色知识一致性对情景记忆编码和提取的影响。结果显示, 在对物体图片进行编码时颜色不一致图片诱发更大N400, 而提取阶段则对颜色一致图片有更多熟悉性加工(实验1); 物体名称能够更快激活典型颜色知识, 对颜色一致名称有更多细节回想(LPC更正) (实验2)。实验结果表明, 颜色一致促进知觉水平的记忆编码, 而阻碍语义水平编码。同时, 颜色一致促进物体图片提取(知觉水平)中的熟悉性和回想过程; 而对物体名称提取(概念水平)的促进作用仅表现在回想上。此外, 颜色与物体名称有着密切联系, 同样影响物体的语义表征, 支持激活-扩散模型理论。本研究从知觉和概念水平上为揭示物体颜色在联结记忆中的作用提供了证据。     

Gender differences in episodic memory and visual working memory including the effects of age

Analysing the relationship between gender and memory, and examining the effects of age on the overall memory-related functioning, are the ongoing goals of psychological research. The present study examined gender and age group differences in episodic memory with respect to the type of task. In addition, these subgroup differences were also analysed in visual working memory. A sample of 366 women and 330 men, aged between 16 and 69 years of age, participated in the current study. Results indicate that women outperformed men on auditory memory tasks, whereas male adolescents and older male adults showed higher level performances on visual episodic and visual working memory measures. However, the size of gender-linked effects varied somewhat across age groups. Furthermore, results partly support a declining performance on episodic memory and visual working memory measures with increasing age. Although age-related losses in episodic memory could not be explained by a decreasing verbal and visuospatial ability with age, women's advantage in auditory episodic memory could be explained by their advantage in verbal ability. Men's higher level visual episodic memory performance was found to result from their advantage in visuospatial ability. Finally, possible methodological, biological, and cognitive explanations for the current findings are discussed.     

Effects of delay on episodic memory retrieval by children with autism spectrum disorder

Twenty‐seven 6‐ to 15‐year‐old children with autism spectrum disorder (ASD) and 32 typically developing (TD) children were questioned about their participation in a set of activities after a 2‐week delay and again after a 2‐month delay using a best practice interview protocol. Interviews were coded for completeness with respect to the gist of the event, the number of narrative details provided, and accuracy. Results indicated that children with ASD did not differ from TD peers on any dimensions of memory after both delays. Specifically, both groups of children provided equivalently complete accounts on both occasions. However, children in both groups provided significantly fewer narrative details about the event in the second interview, and the accuracy rates were lower. The findings indicate that, like TD children, children with ASD can provide meaningful and reliable testimony about an event they personally experienced, but several aspects of their memory reports deteriorate over time.     

Variation in working memory capacity and episodic memory: Examining the importance of encoding specificity

In the present study, we examined the extent to which encoding specificity influences the relation between individual differences in working memory capacity (WMC) and episodic recall. Participants performed a paired associates cued recall task in which a rhyme or a semantic judgment was made during encoding. During recall participants were presented with the cue word along with either a rhyme or semantic cue. Across both rhyme and semantic conditions, encoding and retrieval conditions either matched or mismatched. When encoding and retrieval conditions matched, high WMC individuals outperformed low WMC individuals. When encoding and retrieval conditions mismatched, high and low WMC individuals performed equivalently. Importantly, this occurred because high WMC individuals were hurt more than low WMC individuals when conditions mismatched. These results demonstrate the importance of encoding specificity in the relation between WMC and episodic recall as well as of unifying prior work that has demonstrated that high WMC individuals are hurt more in some recall conditions than are low WMC individuals.     

The role of the executive system in visuo-spatial memory functioning

Participants were presented with a spatial sequence in which between 4 and 10 cells were highlighted. On each trial list length was unknown to the participant who was required to serially recall the last four cells. Processing of longer lists is assumed to call upon the executive system, which is thought to be involved in updating the contents of the short-term visuo-spatial store. Study 1 revealed that loading the executive system with concurrent random letter generation impaired performance on the spatial task especially recall of the early serial positions. However, contrary to expectation the degree of impairment was no greater on the longer lists, where it had been assumed that updating would be occurring. Study 2 confirmed this finding and demonstrated that relative to sequences of known length, under conditions of uncertainty when the list length was unknown, spatial recall was impaired even on short sequences. The present results support the growing consensus, which is suggestive of closer links between visuo-spatial and executive processes. However, it remains unclear whether or not updating is actually occurring on the longer sequences, and if it is, what specific executive processes are involved.     

Different types of working memory binding in epilepsy patients with unilateral anterior temporal lobectomy

The medial temporal lobe is an important structure for long-term memory formation, but its role in working memory is less clear. Recent studies have shown hippocampal involvement during working memory tasks requiring binding of information. It is yet unclear whether this is limited to tasks containing spatial features. The present study contrasted three binding conditions and one single-item condition in patients with unilateral anterior temporal lobectomy.A group of 43 patients with temporal lobectomy (23 left; 20 right) and 20 matched controls were examined with a working memory task assessing spatial relational binding (object–location), non-spatial relational binding (object–object), conjunctive binding (object–colour) and working memory for single items. We varied the delay period (3 or 6 s), as there is evidence showing that delay length may modulate working memory performance.The results indicate that performance was worse for patients than for controls in both relational binding conditions, whereas patients were unimpaired in conjunctive binding. Single-item memory was found to be marginally impaired, due to a deficit on long-delay trials only.In conclusion, working memory binding deficits are found in patients with unilateral anterior temporal lobectomy. The role of the medial temporal lobe in working memory is not limited to tasks containing spatial features. Rather, it seems to be involved in relational binding, but not in conjunctive binding. The medial temporal lobe gets involved when working memory capacity does not suffice, for example when relations have to be maintained or when the delay period is long.