Recall of remote episodic memory in amnesia.

PubMed

Zola-Morgan, S; Cohen, N J; Squire, L R

1983-01-01

Recall of remote episodic memory was assessed in three types of amnesic patient whose remote semantic memory had been evaluated previously. Patients with Korsakoff's syndrome, case N.A. and patients receiving electroconvulsive therapy all succeeded in recalling specific autobiographical episodes in response to single-word cues, and in many conditions performed as well as control subjects. Their pattern of performance generally paralleled that obtained in previous tests of remote semantic memory. These results argue against a view that amnesia reflects a selective deficit of episodic memory and suggest that the semantic-episodic distinction cannot illuminate the fundamental deficit in amnesia. Nor can the facts of amnesia confirm or deny the validity of this distinction in normal memory.

Metamemory beliefs and episodic memory in obstructive sleep apnea syndrome.

PubMed

Daurat, Agnès; Huet, Nathalie; Tiberge, Michel

2010-08-01

This study assessed metamemory and its role in actual episodic memory performance in 26 patients with obstructive sleep apnea syndrome and 27 healthy controls. Metamemory knowledge and memory beliefs were assessed using the Metamemory Inventory in Adulthood. Episodic memory performance was investigated with the Remember/Know paradigm. Subjective sleepiness was evaluated. Patients underwent a polysomnographic assessment. In contrast to the control group's more stable memory beliefs, patients self-assessed their memory as declining across time, and felt more anxious about their memory. There was only a modest difference between patients' self-perceptions of their memory capacities and those of the control group, but patients' actual memory performance was strongly disturbed. While the latter was significantly correlated with severity of obstructive sleep apnea, scores on the Metamemory Inventory in Adulthood scales were not correlated with physiological measures, subjective sleepiness, or episodic memory performance. Obstructive sleep apnea may affect prefrontal cortex functioning and hence the ability to assess one's own memory impairment.

The effects of age, glucose ingestion and gluco-regulatory control on episodic memory.

PubMed

Riby, Leigh Martin; Meikle, Andrew; Glover, Cheryl

2004-09-01

Previous research has been inconclusive regarding the impact of glucose ingestion and gluco-regulatory control on cognitive performance in healthy older adults. The aim of this research was to determine whether glucose specifically enhanced episodic memory in an older population. In addition, the link between individual differences in glucose regulation and the magnitude of the enhancement effect was examined. A within subjects, counterbalanced, crossover design was used with 20 participants (60-80 year olds), each serving as his/her control. Episodic memory was tested by presenting unrelated paired associates followed by immediate and delayed cued recall, and delayed recognition, under single and dual task conditions. In addition, a battery of cognitive tests was administered, including tests of semantic memory, working memory and speed of processing. Glucose ingestion was found to largely facilitate performance of episodic memory. Furthermore, subsidiary analyses found that gluco-regulatory efficiency predicted episodic memory performance in both control and glucose conditions. A boost in performance after glucose ingestion was particularly seen in the episodic memory domain. Notably, strong evidence was provided for the utility of gluco-regulatory control measures as indicators of cognitive decline in the elderly.

Sexual Activity and Cognitive Decline in Older Adults.

PubMed

Allen, Mark S

2018-05-16

This prospective study tested whether sexual activity and emotional closeness during partnered sexual activity relate to cognitive decline (episodic memory performance) in older adulthood. In total, 6016 adults aged 50 and over (2672 men, 3344 women; M age = 66.0 ± 8.8 years) completed an episodic memory task and self-report questions related to health, sexual activity, and emotional closeness. Two years later, participants again completed the episodic memory task. After controlling for demographic and health-related lifestyle factors, more frequent sexual activity and greater emotional closeness during partnered sexual activity were associated with better memory performance. The association between sexual activity and memory performance was stronger among older participants in the sample. Memory performance worsened over 2 years, but change in memory performance was unrelated to sexual activity or emotional closeness during partnered sexual activity. These findings build on experimental research that has found sexual activity enhances episodic memory in non-human animals. Further research using longer timeframes and alternative measures of cognitive decline is recommended.

The role of the thalamus and hippocampus in episodic memory performance in patients with multiple sclerosis.

PubMed

Koenig, Katherine A; Rao, Stephen M; Lowe, Mark J; Lin, Jian; Sakaie, Ken E; Stone, Lael; Bermel, Robert A; Trapp, Bruce D; Phillips, Micheal D

2018-03-01

Episodic memory loss is one of the most common cognitive symptoms in patients with multiple sclerosis (MS), but the pathophysiology of this symptom remains unclear. Both the hippocampus and thalamus have been implicated in episodic memory and show regional atrophy in patients with MS. In this work, we used functional magnetic resonance imaging (fMRI) during a verbal episodic memory task, lesion load, and volumetric measures of the hippocampus and thalamus to assess the relative contributions to verbal and visual-spatial episodic memory. Functional activation, lesion load, and volumetric measures from 32 patients with MS and 16 healthy controls were used in a predictive analysis of episodic memory function. After adjusting for disease duration, immediate recall performance on a visual-spatial episodic memory task was significantly predicted by hippocampal volume ( p < 0.003). Delayed recall on the same task was significantly predicted by volume of the left thalamus ( p < 0.003). For both memory measures, functional activation of the thalamus during encoding was more predictive than that of volume measures ( p < 0.002). Our results suggest that functional activation may be useful as a predictive measure of episodic memory loss in patients with MS.

Episodic memory and executive functioning in currently depressed patients compared to healthy controls.

PubMed

Pauls, Franz; Petermann, Franz; Lepach, Anja Christina

2015-01-01

At present, little is still known about the link between depression, memory and executive functioning. This study examined whether there are memory-related impairments in depressed patients and whether the size of such deficits depends on the age group and on specific types of cognitive measures. Memory performances of 215 clinically depressed patients were compared to the data of a matched control sample. Regression analyses were performed to determine the extent to which executive dysfunctions contributed to episodic memory impairments. When compared with healthy controls, significantly lower episodic memory and executive functioning performances were found for depressed patients of all age groups. Effect sizes appeared to vary across different memory and executive functioning measures. The extent to which executive dysfunctions could explain episodic memory impairments varied depending on the type of measure examined. These findings emphasise the need to consider memory-related functioning of depressed patients in the context of therapeutic treatments.

How autobiographical memories can support episodic recall: transfer and maintenance effect of memory training with old-old low-autonomy adults.

PubMed

Carretti, Barbara; Facchini, Giulia; Nicolini, Chiara

2011-02-01

A large body of research has demonstrated that, although specific memory activities can enhance the memory performance of healthy older adults, the extent of the increment is negatively associated with age. Conversely, few studies have examined the case of healthy elderly people not living alone. This study has two mains goals: to understand whether older adults with limited autonomy can benefit from activities devoted to increasing their episodic memory performance, and to test the efficacy of a memory training program based on autobiographical memories, in terms of transfer and maintenance effect. We postulated that being able to rely on stable autobiographical memories (intrinsically associated with emotions) would be a valuable memory aid. Memory training was given to healthy older adults (aged 75-85) living in a retirement home. Two programs were compared: in the first, participants were primed to recall autobiographical memories around certain themes, and then to complete a set of episodic memory tasks (experimental group); in the second, participants were only given the episodic tasks (control group). Both groups improved their performance from pre- to post-test. However, the experimental group reported a greater feeling of well-being after the training, and maintained the training gains relating to episodic performance after three months. Our findings suggest that specific memory activities are beneficial to elderly people living in a retirement home context. In addition, training based on reactivation of autobiographical memories is shown to produce a long-lasting effect on memory performance.

Episodic and working memory deficits in alcoholic Korsakoff patients: the continuity theory revisited.

PubMed

Pitel, Anne Lise; Beaunieux, Hélène; Witkowski, Thomas; Vabret, François; de la Sayette, Vincent; Viader, Fausto; Desgranges, Béatrice; Eustache, Francis

2008-07-01

The exact nature of episodic and working memory impairments in alcoholic Korsakoff patients (KS) remains unclear, as does the specificity of these neuropsychological deficits compared with those of non-Korsakoff alcoholics (AL). The goals of the present study were therefore to (1) specify the nature of episodic and working memory impairments in KS, (2) determine the specificity of the KS neuropsychological profile compared with the AL profile, and (3) observe the distribution of individual performances within the 2 patient groups. We investigated episodic memory (encoding and retrieval abilities, contextual memory and state of consciousness associated with memories), the slave systems of working memory (phonological loop, visuospatial sketchpad and episodic buffer) and executive functions (inhibition, flexibility, updating and integration abilities) in 14 strictly selected KS, 40 AL and 55 control subjects (CS). Compared with CS, KS displayed impairments of episodic memory encoding and retrieval, contextual memory, recollection, the slave systems of working memory and executive functions. Although episodic memory was more severely impaired in KS than in AL, the single specificity of the KS profile was a disproportionately large encoding deficit. Apart from organizational and updating abilities, the slave systems of working memory and inhibition, flexibility and integration abilities were impaired to the same extent in both alcoholic groups. However, some KS were unable to complete the most difficult executive tasks. There was only a partial overlap of individual performances by KS and AL for episodic memory and a total mixture of the 2 groups for working memory. Korsakoff's syndrome encompasses impairments of the different episodic and working memory components. AL and KS displayed similar profiles of episodic and working memory deficits, in accordance with neuroimaging investigations showing similar patterns of brain damage in both alcoholic groups.

Memory and Obstructive Sleep Apnea: A Meta-Analysis

PubMed Central

Wallace, Anna; Bucks, Romola S.

2013-01-01

Study Objectives: To examine episodic memory performance in individuals with obstructive sleep apnea (OSA). Design Meta-analysis was used to synthesize results from individual studies examining the impact of OSA on episodic memory performance. The performance of individuals with OSA was compared to healthy controls or normative data. Participants Forty-two studies were included, comprising 2,294 adults with untreated OSA and 1,364 healthy controls. Studies that recorded information about participants at baseline prior to treatment interventions were included in the analysis. Measurements Participants were assessed with tasks that included a measure of episodic memory: immediate recall, delayed recall, learning, and/or recognition memory. Results: The results of the meta-analyses provide evidence that individuals with OSA are significantly impaired when compared to healthy controls on verbal episodic memory (immediate recall, delayed recall, learning, and recognition) and visuo-spatial episodic memory (immediate and delayed recall), but not visual immediate recall or visuo-spatial learning. When patients were compared to norms, negative effects of OSA were found only in verbal immediate and delayed recall. Conclusions: This meta-analysis contributes to understanding of the nature of episodic memory deficits in individuals with OSA. Impairments to episodic memory are likely to affect the daily functioning of individuals with OSA. Citation Wallace A; Bucks RS. Memory and obstructive sleep apnea: a meta-analysis. SLEEP 2013;36(2):203-220. PMID:23372268

Mindfulness Enhances Episodic Memory Performance: Evidence from a Multimethod Investigation

PubMed Central

Goodman, Robert J.; Ryan, Richard M.; Anālayo, Bhikkhu

2016-01-01

Training in mindfulness, classically described as a receptive attentiveness to present events and experiences, has been shown to improve attention and working memory. Both are key to long-term memory formation, and the present three-study series used multiple methods to examine whether mindfulness would enhance episodic memory, a key form of long-term memory. In Study 1 (N = 143), a self-reported state of mindful attention predicted better recognition performance in the Remember-Know (R-K) paradigm. In Study 2 (N = 93), very brief training in a focused attention form of mindfulness also produced better recognition memory performance on the R-K task relative to a randomized, well-matched active control condition. Study 3 (N = 57) extended these findings by showing that relative to randomized active and inactive control conditions the effect of very brief mindfulness training generalized to free-recall memory performance. This study also found evidence for mediation of the mindfulness training—episodic memory relation by intrinsic motivation. These findings indicate that mindful attention can beneficially impact motivation and episodic memory, with potential implications for educational and occupational performance. PMID:27115491

Mindfulness Enhances Episodic Memory Performance: Evidence from a Multimethod Investigation.

PubMed

Brown, Kirk Warren; Goodman, Robert J; Ryan, Richard M; Anālayo, Bhikkhu

2016-01-01

Training in mindfulness, classically described as a receptive attentiveness to present events and experiences, has been shown to improve attention and working memory. Both are key to long-term memory formation, and the present three-study series used multiple methods to examine whether mindfulness would enhance episodic memory, a key form of long-term memory. In Study 1 (N = 143), a self-reported state of mindful attention predicted better recognition performance in the Remember-Know (R-K) paradigm. In Study 2 (N = 93), very brief training in a focused attention form of mindfulness also produced better recognition memory performance on the R-K task relative to a randomized, well-matched active control condition. Study 3 (N = 57) extended these findings by showing that relative to randomized active and inactive control conditions the effect of very brief mindfulness training generalized to free-recall memory performance. This study also found evidence for mediation of the mindfulness training-episodic memory relation by intrinsic motivation. These findings indicate that mindful attention can beneficially impact motivation and episodic memory, with potential implications for educational and occupational performance.

Neuroanatomical and Cognitive Mediators of Age-Related Differences in Episodic Memory

PubMed Central

Head, Denise; Rodrigue, Karen M.; Kennedy, Kristen M.; Raz, Naftali

2009-01-01

Aging is associated with declines in episodic memory. In this study, the authors used a path analysis framework to explore the mediating role of differences in brain structure, executive functions, and processing speed in age-related differences in episodic memory. Measures of regional brain volume (prefrontal gray and white matter, caudate, hippocampus, visual cortex), executive functions (working memory, inhibitory control, task switching, temporal processing), processing speed, and episodic memory were obtained in a sample of young and older adults. As expected, age was linked to reduction in regional brain volumes and cognitive performance. Moreover, neural and cognitive factors completely mediated age differences in episodic memory. Whereas hippocampal shrinkage directly affected episodic memory, prefrontal volumetric reductions influenced episodic memory via limitations in working memory and inhibitory control. Age-related slowing predicted reduced efficiency in temporal processing, working memory, and inhibitory control. Lastly, poorer temporal processing directly affected episodic memory. No direct effects of age on episodic memory remained once these factors were taken into account. These analyses highlight the value of a multivariate approach with the understanding of complex relationships in cognitive and brain aging. PMID:18590361

A SEMantic and EPisodic Memory Test (SEMEP) Developed within the Embodied Cognition Framework: Application to Normal Aging, Alzheimer's Disease and Semantic Dementia.

PubMed

Vallet, Guillaume T; Hudon, Carol; Bier, Nathalie; Macoir, Joël; Versace, Rémy; Simard, Martine

2017-01-01

Embodiment has highlighted the importance of sensory-motor components in cognition. Perception and memory are thus very tightly bound together, and episodic and semantic memories should rely on the same grounded memory traces. Reduced perception should then directly reduce the ability to encode and retrieve an episodic memory, as in normal aging. Multimodal integration deficits, as in Alzheimer's disease, should lead to more severe episodic memory impairment. The present study introduces a new memory test developed to take into account these assumptions. The SEMEP (SEMantic-Episodic) memory test proposes to assess conjointly semantic and episodic knowledge across multiple tasks: semantic matching, naming, free recall, and recognition. The performance of young adults is compared to healthy elderly adults (HE), patients with Alzheimer's disease (AD), and patients with semantic dementia (SD). The results show specific patterns of performance between the groups. HE commit memory errors only for presented but not to be remembered items. AD patients present the worst episodic memory performance associated with intrusion errors (recall or recognition of items never presented). They were the only group to not benefit from a visual isolation (addition of a yellow background), a method known to increase the distinctiveness of the memory traces. Finally, SD patients suffer from the most severe semantic impairment. To conclude, confusion errors are common across all the elderly groups, whereas AD was the only group to exhibit regular intrusion errors and SD patients to show severe semantic impairment.

Computational Model-Based Prediction of Human Episodic Memory Performance Based on Eye Movements

NASA Astrophysics Data System (ADS)

Sato, Naoyuki; Yamaguchi, Yoko

Subjects' episodic memory performance is not simply reflected by eye movements. We use a ‘theta phase coding’ model of the hippocampus to predict subjects' memory performance from their eye movements. Results demonstrate the ability of the model to predict subjects' memory performance. These studies provide a novel approach to computational modeling in the human-machine interface.

Distinct neuroanatomical bases of episodic and semantic memory performance in Alzheimer's disease.

PubMed

Hirni, Daniela I; Kivisaari, Sasa L; Monsch, Andreas U; Taylor, Kirsten I

2013-04-01

Alzheimer's disease (AD) neurofibrillary pathology begins in the medial perirhinal cortex (mPRC) before spreading to the entorhinal cortex (ERC) and hippocampus (HP) in anterior medial temporal lobe (aMTL). While the role of the ERC/HP complex in episodic memory formation is well-established, recent research suggests that the PRC is required to form semantic memories of individual objects. We aimed to test whether commonly used clinical measures of episodic and semantic memory are distinctly associated with ERC/HP and mPRC integrity, respectively, in healthy mature individuals and very early AD patients. One hundred thirty normal controls, 32 amnestic mild cognitive impairment patients, some of whom are in the earliest (i.e., preclinical) stages of AD, and ten early-stage AD patients received neuropsychological testing and high-resolution anatomic and diffusion MRI. Voxel-based regression analyses tested for regions where episodic memory (delayed recall scores on the California Verbal Learning and Rey Osterrieth Complex Figure Tests) and semantic memory (Boston Naming Test, category fluency) performance correlated with gray matter (GM) regions of interest and whole-brain fractional anisotropy (FA) voxel values. When controlling for the opposing memory performance, poorer episodic memory performance was associated with reduced bilateral ERC/HP GM volume and related white matter integrity, but not with mPRC GM volume. Poor semantic memory performance was associated with both reduced left mPRC and ERC/HP GM volume, as well as reduced FA values in white matter tracts leading to the PRC. These results indicate a partial division of labor within the aMTL and suggest that mPRC damage in very early AD may be detectable with common clinical tests of semantic memory if episodic memory performance is controlled. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prefrontal and medial temporal contributions to episodic memory-based reasoning.

PubMed

Suzuki, Chisato; Tsukiura, Takashi; Mochizuki-Kawai, Hiroko; Shigemune, Yayoi; Iijima, Toshio

2009-03-01

Episodic memory retrieval and reasoning are fundamental psychological components of our daily lives. Although previous studies have investigated the brain regions associated with these processes separately, the neural mechanisms of reasoning based on episodic memory retrieval are largely unknown. Here, we investigated the neural correlates underlying episodic memory-based reasoning using functional magnetic resonance imaging (fMRI). During fMRI scanning, subjects performed three tasks: reasoning, episodic memory retrieval, and episodic memory-based reasoning. We identified dissociable activations related to reasoning, episodic memory retrieval, and linking processes between the two. Regions related to reasoning were identified in the left ventral prefrontal cortices (PFC), and those related to episodic memory retrieval were found in the right medial temporal lobe (MTL) regions. In addition, activations predominant in the linking process between the two were found in the left dorsal and right ventral PFC. These findings suggest that episodic memory-based reasoning is composed of at least three processes, i.e., reasoning, episodic memory retrieval, and linking processes between the two, and that activation of both the PFC and MTL is crucial in episodic memory-based reasoning. These findings are the first to demonstrate that PFC and MTL regions contribute differentially to each process in episodic memory-based reasoning.

Contextualization: Memory Formation and Retrieval in a Nested Environment

NASA Astrophysics Data System (ADS)

Piefke, Martina; Markowitsch, Hans J.

Episodic memory functions are highly context-dependent. This is true for both experimental and autobiographical episodic memory. We here review neuropsychological and neuroimaging evidence for effects of differential encoding and retrieval contexts on episodic memory performance as well as the underlying neurofunctional mechanisms. In studies of laboratory episodic memory, the influence of context parameters can be assessed by experimental manipulations. Such experiments suggest that contextual variables mainly affect prefrontal functions supporting executive processes involved in episodic learning and retrieval. Context parameters affecting episodic autobiographical memory are far more complex and cannot easily be controlled. Data support the view that not only prefrontal, but also further medial temporal and posterior parietal regions mediating the re-experience and emotional evaluation of personal memories are highly influenced by changing contextual variables of memory encoding and retrieval. Based on our review of available data, we thus suggest that experimental and autobiographical episodic memories are influenced by both overlapping and differential context parameters.

Music-related reward responses predict episodic memory performance.

PubMed

Ferreri, Laura; Rodriguez-Fornells, Antoni

2017-12-01

Music represents a special type of reward involving the recruitment of the mesolimbic dopaminergic system. According to recent theories on episodic memory formation, as dopamine strengthens the synaptic potentiation produced by learning, stimuli triggering dopamine release could result in long-term memory improvements. Here, we behaviourally test whether music-related reward responses could modulate episodic memory performance. Thirty participants rated (in terms of arousal, familiarity, emotional valence, and reward) and encoded unfamiliar classical music excerpts. Twenty-four hours later, their episodic memory was tested (old/new recognition and remember/know paradigm). Results revealed an influence of music-related reward responses on memory: excerpts rated as more rewarding were significantly better recognized and remembered. Furthermore, inter-individual differences in the ability to experience musical reward, measured through the Barcelona Music Reward Questionnaire, positively predicted memory performance. Taken together, these findings shed new light on the relationship between music, reward and memory, showing for the first time that music-driven reward responses are directly implicated in higher cognitive functions and can account for individual differences in memory performance.

Ageing-related stereotypes in memory: When the beliefs come true.

PubMed

Bouazzaoui, Badiâa; Follenfant, Alice; Ric, François; Fay, Séverine; Croizet, Jean-Claude; Atzeni, Thierry; Taconnat, Laurence

2016-01-01

Age-related stereotype concerns culturally shared beliefs about the inevitable decline of memory with age. In this study, stereotype priming and stereotype threat manipulations were used to explore the impact of age-related stereotype on metamemory beliefs and episodic memory performance. Ninety-two older participants who reported the same perceived memory functioning were divided into two groups: a threatened group and a non-threatened group (control). First, the threatened group was primed with an ageing stereotype questionnaire. Then, both groups were administered memory complaints and memory self-efficacy questionnaires to measure metamemory beliefs. Finally, both groups were administered the Logical Memory task to measure episodic memory, for the threatened group the instructions were manipulated to enhance the stereotype threat. Results indicated that the threatened individuals reported more memory complaints and less memory efficacy, and had lower scores than the control group on the logical memory task. A multiple mediation analysis revealed that the stereotype threat effect on the episodic memory performance was mediated by both memory complaints and memory self-efficacy. This study revealed that stereotype threat impacts belief in one's own memory functioning, which in turn impairs episodic memory performance.

How does intentionality of encoding affect memory for episodic information?

PubMed Central

Craig, Michael; Butterworth, Karla; Nilsson, Jonna; Hamilton, Colin J.; Gallagher, Peter

2016-01-01

Episodic memory enables the detailed and vivid recall of past events, including target and wider contextual information. In this paper, we investigated whether/how encoding intentionality affects the retention of target and contextual episodic information from a novel experience. Healthy adults performed (1) a What-Where-When (WWW) episodic memory task involving the hiding and delayed recall of a number of items (what) in different locations (where) in temporally distinct sessions (when) and (2) unexpected tests probing memory for wider contextual information from the WWW task. Critically, some participants were informed that memory for WWW information would be subsequently probed (intentional group), while this came as a surprise for others (incidental group). The probing of contextual information came as a surprise for all participants. Participants also performed several measures of episodic and nonepisodic cognition from which common episodic and nonepisodic factors were extracted. Memory for target (WWW) and contextual information was superior in the intentional group compared with the incidental group. Memory for target and contextual information was unrelated to factors of nonepisodic cognition, irrespective of encoding intentionality. In addition, memory for target information was unrelated to factors of episodic cognition. However, memory for wider contextual information was related to some factors of episodic cognition, and these relationships differed between the intentional and incidental groups. Our results lead us to propose the hypothesis that intentional encoding of episodic information increases the coherence of the representation of the context in which the episode took place. This hypothesis remains to be tested. PMID:27918286

Episodic Memory in Detoxified Alcoholics: Contribution of Grey Matter Microstructure Alteration

PubMed Central

Chanraud, Sandra; Leroy, Claire; Martelli, Catherine; Kostogianni, Nikoleta; Delain, Françoise; Aubin, Henri-Jean; Reynaud, Michel; Martinot, Jean-Luc

2009-01-01

Even though uncomplicated alcoholics may likely have episodic memory deficits, discrepancies exist regarding to the integrity of brain regions that underlie this function in healthy subjects. Possible relationships between episodic memory and 1) brain microstructure assessed by magnetic resonance diffusion tensor imaging (DTI), 2) brain volumes assessed by voxel-based morphometry (VBM) were investigated in uncomplicated, detoxified alcoholics. Diffusion and morphometric analyses were performed in 24 alcohol dependent men without neurological or somatic complications and in 24 healthy men. The mean apparent coefficient of diffusion (ADC) and grey matter volumes were measured in the whole brain. Episodic memory performance was assessed using a French version of the Free and Cued Selective Reminding Test (FCSRT). Correlation analyses between verbal episodic memory, brain microstructure, and brain volumes were carried out using SPM2 software. In those with alcohol dependence, higher ADC was detected mainly in frontal, temporal and parahippocampal regions, and in the cerebellum. In alcoholics, regions with higher ADC typically also had lower grey matter volume. Low verbal episodic memory performance in alcoholism was associated with higher mean ADC in parahippocampal areas, in frontal cortex and in the left temporal cortex; no correlation was found between regional volumes and episodic memory scores. Regression analyses for the control group were not significant. These findings support the hypothesis that regional microstructural but no macrostructural alteration of the brain might be responsible, at least in part, for episodic memory deficits in alcohol dependence. PMID:19707568

Structural development of the hippocampus and episodic memory: developmental differences along the anterior/posterior axis.

PubMed

DeMaster, Dana; Pathman, Thanujeni; Lee, Joshua K; Ghetti, Simona

2014-11-01

The hippocampus is critically involved in episodic memory, yet relatively little is known about how the development of this structure contributes to the development of episodic memory during middle to late childhood. Previous research has inconsistently reported associations between hippocampal volume and episodic memory performance during this period. We argue that this inconsistency may be due to assessing the hippocampus as a whole, and propose to examine associations separately for subregions along the longitudinal axis of the hippocampus. In the present study, we examined age-related differences in volumes of the hippocampal head, body, and tail, and collected episodic memory measures in children ages 8-11 years and young adults (N = 62). We found that adults had a smaller right hippocampal head, larger hippocampal body bilaterally, and smaller right hippocampal tail compared with children. In adults, but not in children, better episodic memory performance was associated with smaller right hippocampal head and larger hippocampal body. In children, but not in adults, better episodic memory was associated with larger left hippocampal tail. Overall, the results suggest that protracted development of hippocampal subregions contribute to age-related differences in episodic memory. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Overlap in the functional neural systems involved in semantic and episodic memory retrieval.

PubMed

Rajah, M N; McIntosh, A R

2005-03-01

Neuroimaging and neuropsychological data suggest that episodic and semantic memory may be mediated by distinct neural systems. However, an alternative perspective is that episodic and semantic memory represent different modes of processing within a single declarative memory system. To examine whether the multiple or the unitary system view better represents the data we conducted a network analysis using multivariate partial least squares (PLS ) activation analysis followed by covariance structural equation modeling (SEM) of positron emission tomography data obtained while healthy adults performed episodic and semantic verbal retrieval tasks. It is argued that if performance of episodic and semantic retrieval tasks are mediated by different memory systems, then there should differences in both regional activations and interregional correlations related to each type of retrieval task, respectively. The PLS results identified brain regions that were differentially active during episodic retrieval versus semantic retrieval. Regions that showed maximal differences in regional activity between episodic retrieval tasks were used to construct separate functional models for episodic and semantic retrieval. Omnibus tests of these functional models failed to find a significant difference across tasks for both functional models. The pattern of path coefficients for the episodic retrieval model were not different across tasks, nor were the path coefficients for the semantic retrieval model. The SEM results suggest that the same memory network/system was engaged across tasks, given the similarities in path coefficients. Therefore, activation differences between episodic and semantic retrieval may ref lect variation along a continuum of processing during task performance within the context of a single memory system.

A single bout of resistance exercise can enhance episodic memory performance.

PubMed

Weinberg, Lisa; Hasni, Anita; Shinohara, Minoru; Duarte, Audrey

2014-11-01

Acute aerobic exercise can be beneficial to episodic memory. This benefit may occur because exercise produces a similar physiological response as physical stressors. When administered during consolidation, acute stress, both physical and psychological, consistently enhances episodic memory, particularly memory for emotional materials. Here we investigated whether a single bout of resistance exercise performed during consolidation can produce episodic memory benefits 48 h later. We used a one-leg knee extension/flexion task for the resistance exercise. To assess the physiological response to the exercise, we measured salivary alpha amylase (a biomarker of central norepinephrine), heart rate, and blood pressure. To test emotional episodic memory, we used a remember-know recognition memory paradigm with equal numbers of positive, negative, and neutral IAPS images as stimuli. The group that performed the exercise, the active group, had higher overall recognition accuracy than the group that did not exercise, the passive group. We found a robust effect of valence across groups, with better performance on emotional items as compared to neutral items and no difference between positive and negative items. This effect changed based on the physiological response to the exercise. Within the active group, participants with a high physiological response to the exercise were impaired for neutral items as compared to participants with a low physiological response to the exercise. Our results demonstrate that a single bout of resistance exercise performed during consolidation can enhance episodic memory and that the effect of valence on memory depends on the physiological response to the exercise. Copyright © 2014 Elsevier B.V. All rights reserved.

Episodic memory impairment in systemic lupus erythematosus: involvement of thalamic structures.

PubMed

Zimmermann, Nicolle; Corrêa, Diogo Goulart; Netto, Tania Maria; Kubo, Tadeu; Pereira, Denis Batista; Fonseca, Rochele Paz; Gasparetto, Emerson Leandro

2015-02-01

Episodic memory deficits in systemic lupus erythematosus (SLE) have been frequently reported in the literature; however, little is known about the neural correlates of these deficits. We investigated differences in the volumes of different brain structures of SLE patients with and without episodic memory impairments diagnosed by the Rey Auditory Verbal Learning Test (RAVLT). Groups were paired based on age, education, sex, Mini Mental State Examination score, accumulation of disease burden (SLICC), and focused attention dimension score. Patients underwent magnetic resonance imaging (MRI). Cortical volumetric reconstruction and segmentation of the MR images were performed with the FreeSurfer software program. SLE patients with episodic memory deficits presented shorter time of diagnosis than SLE patients without episodic memory deficits. ANOVA revealed that SLE patients with episodic memory deficits had a larger third ventricle volume than SLE patients without episodic memory deficits and controls. Additionally, covariance analysis indicated group effects on the bilateral thalamus and on the third ventricle. Our findings indicate that episodic memory may be impaired in SLE patients with normal hippocampal volume. In addition, the thalamus may undergo volumetric changes associated with episodic memory loss in SLE.

Better together: Left and right hemisphere engagement to reduce age-related memory loss.

PubMed

Brambilla, Michela; Manenti, Rosa; Ferrari, Clarissa; Cotelli, Maria

2015-10-15

Episodic memory is a cognitive function that appears more susceptible than others to the effects of aging. The main aim of this study is to investigate if the magnitude of functional hemispheric lateralization during episodic memory test was positively correlated with memory performance, proving the presence of a beneficial pattern of neural processing in high-performing older adults but not in low-performing participants. We have applied anodal transcranial Direct Current Stimulation (tDCS) or sham stimulation over left and right hemisphere in a group of young subjects and in high-performing and low-performing older participants during an experimental verbal episodic memory task. Remarkably, young individuals and high-performing older adults exhibited similar performances on episodic memory tasks and both groups showed symmetrical recruitment of left and right areas during memory retrieval. In contrast, low-performing older adults, who obtained lower scores on the memory tasks, demonstrated a greater engagement of the left hemisphere during verbal memory task. Furthermore, structural equation model was performed for analyzing the interrelations between the index of interhemispheric asymmetry and several neuropsychological domains. We found that the bilateral engagement of dorsolateral prefrontal cortex and parietal cortex regions had a direct correlation with memory and executive functions evaluated as latent constructs. These findings drew attention to brain maintenance hypothesis. The potential of neurostimulation in cognitive enhancement is particularly promising to prevent memory loss during aging. Copyright © 2015 Elsevier B.V. All rights reserved.

Differential involvement of knowledge representation and executive control in episodic memory performance in young and older adults.

PubMed

Bouazzaoui, Badiâa; Fay, Séverine; Taconnat, Laurence; Angel, Lucie; Vanneste, Sandrine; Isingrini, Michel

2013-06-01

Craik and Bialystok (2006, 2008) postulated that examining the evolution of knowledge representation and control processes across the life span could help in understanding age-related cognitive changes. The present study explored the hypothesis that knowledge representation and control processes are differentially involved in the episodic memory performance of young and older adults. Young and older adults were administered a cued-recall task and tests of crystallized knowledge and executive functioning to measure representation and control processes, respectively. Results replicate the classic finding that executive and cued-recall performance decline with age, but crystallized-knowledge performance does not. Factor analysis confirmed the independence of representation and control. Correlation analyses showed that the memory performance of younger adults was correlated with representation but not with control measures, whereas the memory performance of older adults was correlated with both representation and control measures. Regression analyses indicated that the control factor was the main predictor of episodic-memory performance for older adults, with the representation factor adding an independent contribution, but the representation factor was the sole predictor for young adults. This finding supports the view that factors sustaining episodic memory vary from young adulthood to old age; representation was shown to be important throughout adulthood, and control was also important for older adults. The results also indicated that control and representation modulate age-group-related variance in episodic memory.

Episodic representations support early semantic learning: evidence from midazolam induced amnesia.

PubMed

Merritt, Paul; Hirshman, Elliot; Zamani, Shane; Hsu, John; Berrigan, Michael

2006-07-01

Current controversy exists regarding the role of episodic representations in the formation of long-term semantic memories. Using the drug midazolam to induce temporary amnesia we tested participants' memories for newly learned facts in a semantic cue condition or an episodic and semantic cue condition. Following midazolam administration, memory performance was superior in the episodic and semantic condition, suggesting early semantic learning is supported by episodic representations.

The effects of marital status on episodic and semantic memory in healthy middle-aged and old individuals.

PubMed

Mousavi-Nasab, S-M-Hossein; Kormi-Nouri, Reza; Sundström, Anna; Nilsson, Lars-Göran

2012-02-01

The present study examined the influences of marital status on different episodic and semantic memory tasks. A total of 1882 adult men and women participated in a longitudinal project (Betula) on memory, health and aging. The participants were grouped into two age cohorts, 35-60 and 65-85, and studied over a period of 5 years. Episodic memory tasks concerned recognition and recall, whereas semantic memory tasks concerned knowledge and fluency. The results showed, after controlling for education, some diseases, chronological age and leisure activity as covariates, that there were significant differences between married and single individuals in episodic memory, but not in semantic memory. Married people showed significantly better memory performances than singles in both subsystems of episodic memory, that is, recall and recognition. Also, the rate of decline in episodic memory was significantly larger for singles and widowed than other groups over the 5-year time period in both age groups. The findings demonstrate that the positive relation found between marriage and health can be extended to the relation between marriage and cognitive performance. This effect might be explained by the role played by cognitive stimulation in memory and cognition. © 2011 The Authors. Scandinavian Journal of Psychology © 2011 The Scandinavian Psychological Associations.

Deep ART Neural Model for Biologically Inspired Episodic Memory and Its Application to Task Performance of Robots.

PubMed

Park, Gyeong-Moon; Yoo, Yong-Ho; Kim, Deok-Hwa; Kim, Jong-Hwan; Gyeong-Moon Park; Yong-Ho Yoo; Deok-Hwa Kim; Jong-Hwan Kim; Yoo, Yong-Ho; Park, Gyeong-Moon; Kim, Jong-Hwan; Kim, Deok-Hwa

2018-06-01

Robots are expected to perform smart services and to undertake various troublesome or difficult tasks in the place of humans. Since these human-scale tasks consist of a temporal sequence of events, robots need episodic memory to store and retrieve the sequences to perform the tasks autonomously in similar situations. As episodic memory, in this paper we propose a novel Deep adaptive resonance theory (ART) neural model and apply it to the task performance of the humanoid robot, Mybot, developed in the Robot Intelligence Technology Laboratory at KAIST. Deep ART has a deep structure to learn events, episodes, and even more like daily episodes. Moreover, it can retrieve the correct episode from partial input cues robustly. To demonstrate the effectiveness and applicability of the proposed Deep ART, experiments are conducted with the humanoid robot, Mybot, for performing the three tasks of arranging toys, making cereal, and disposing of garbage.

How does intentionality of encoding affect memory for episodic information?

PubMed

Craig, Michael; Butterworth, Karla; Nilsson, Jonna; Hamilton, Colin J; Gallagher, Peter; Smulders, Tom V

2016-11-01

Episodic memory enables the detailed and vivid recall of past events, including target and wider contextual information. In this paper, we investigated whether/how encoding intentionality affects the retention of target and contextual episodic information from a novel experience. Healthy adults performed (1) a What-Where-When (WWW) episodic memory task involving the hiding and delayed recall of a number of items (what) in different locations (where) in temporally distinct sessions (when) and (2) unexpected tests probing memory for wider contextual information from the WWW task. Critically, some participants were informed that memory for WWW information would be subsequently probed (intentional group), while this came as a surprise for others (incidental group). The probing of contextual information came as a surprise for all participants. Participants also performed several measures of episodic and nonepisodic cognition from which common episodic and nonepisodic factors were extracted. Memory for target (WWW) and contextual information was superior in the intentional group compared with the incidental group. Memory for target and contextual information was unrelated to factors of nonepisodic cognition, irrespective of encoding intentionality. In addition, memory for target information was unrelated to factors of episodic cognition. However, memory for wider contextual information was related to some factors of episodic cognition, and these relationships differed between the intentional and incidental groups. Our results lead us to propose the hypothesis that intentional encoding of episodic information increases the coherence of the representation of the context in which the episode took place. This hypothesis remains to be tested. © 2016 Craig et al.; Published by Cold Spring Harbor Laboratory Press.

Does the greater involvement of executive control in memory with age act as a compensatory mechanism?

PubMed

Bouazzaoui, Badiâa; Angel, Lucie; Fay, Séverine; Taconnat, Laurence; Charlotte, Froger; Isingrini, Michel

2014-03-01

Recent behavioural and imaging data have shown that memory functioning seems to rely more on executive functions and on the prefrontal cortex (PFC) in older than in young adults. Using a behavioural approach, our objective was to confirm the hypothesis that young and older adults present different patterns of correlation between episodic memory performance and executive functioning. We report three studies comparing the correlations of young and older adults in a broad range of episodic memory and executive function tasks. The results indicated that memory and executive performance were consistently and significantly correlated in older but not in younger adults. Regression analyses confirmed that age-related differences in episodic memory performance could be explained by individual differences in executive functioning. The results are consistent with the view that memory functioning in aging is accompanied by a shift from automatic to controlled forms of processing. They also generalise the executive hypothesis of episodic memory aging and are in line with the idea that executive functions act as a compensatory mechanism against age-related memory decline.

Material-specific difficulties in episodic memory tasks in mild traumatic brain injury.

PubMed

Tsirka, Vassiliki; Simos, Panagiotis; Vakis, Antonios; Vourkas, Michael; Arzoglou, Vasileios; Syrmos, Nikolaos; Stavropoulos, Stavros; Micheloyannis, Sifis

2010-03-01

The study examines acute, material-specific secondary memory performance in 26 patients with mild traumatic brain injury (MTBI) and 26 healthy controls, matched on demographic variables and indexes of crystallized intelligence. Neuropsychological tests were used to evaluate primary and secondary memory, executive functions, and verbal fluency. Participants were also tested on episodic memory tasks involving words, pseudowords, pictures of common objects, and abstract kaleidoscopic images. Patients showed reduced performance on episodic memory measures, and on tasks associated with visuospatial processing and executive function (Trail Making Test part B, semantic fluency). Significant differences between groups were also noted for correct rejections and response bias on the kaleidoscope task. MTBI patients' reduced performance on memory tasks for complex, abstract stimuli can be attributed to a dysfunction in the strategic component of memory process.

Spatial Navigation Impairments Among Intellectually High-Functioning Adults With Autism Spectrum Disorder: Exploring Relations With Theory of Mind, Episodic Memory, and Episodic Future Thinking

PubMed Central

2013-01-01

Research suggests that spatial navigation relies on the same neural network as episodic memory, episodic future thinking, and theory of mind (ToM). Such findings have stimulated theories (e.g., the scene construction and self-projection hypotheses) concerning possible common underlying cognitive capacities. Consistent with such theories, autism spectrum disorder (ASD) is characterized by concurrent impairments in episodic memory, episodic future thinking, and ToM. However, it is currently unclear whether spatial navigation is also impaired. Hence, ASD provides a test case for the scene construction and self-projection theories. The study of spatial navigation in ASD also provides a test of the extreme male brain theory of ASD, which predicts intact or superior navigation (purportedly a systemizing skill) performance among individuals with ASD. Thus, the aim of the current study was to establish whether spatial navigation in ASD is impaired, intact, or superior. Twenty-seven intellectually high-functioning adults with ASD and 28 sex-, age-, and IQ-matched neurotypical comparison adults completed the memory island virtual navigation task. Tests of episodic memory, episodic future thinking, and ToM were also completed. Participants with ASD showed significantly diminished performance on the memory island task, and performance was positively related to ToM and episodic memory, but not episodic future thinking. These results suggest that (contra the extreme male brain theory) individuals with ASD have impaired survey-based navigation skills—that is, difficulties generating cognitive maps of the environment—and adds weight to the idea that scene construction/self-projection are impaired in ASD. The theoretical and clinical implications of these results are discussed. PMID:24364620

Autobiographical memory in semantic dementia: implication for theories of limbic-neocortical interaction in remote memory.

PubMed

McKinnon, Margaret C; Black, Sandra E; Miller, Bruce; Moscovitch, Morris; Levine, Brian

2006-01-01

We examined autobiographical memory performance in two patients with semantic dementia using a novel measure, the Autobiographical Interview [Levine, Svoboda, Hay, Winocur, & Moscovitch (2002). Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689], that is capable of dissociating episodic and personal semantic recall under varying levels of retrieval support. Earlier reports indicated that patients with semantic dementia demonstrate autobiographical episodic memory loss following a "reverse gradient" by which recent memories are preserved relative to remote memories. We found limited evidence for this pattern at conditions of low retrieval support. When structured probing was provided, patients' autobiographical memory performance was similar to that of controls. Retesting of one patient after 1 year indicated that retrieval support was insufficient to bolster performance following progressive prefrontal volume loss, as documented with quantified structural neuroimaging. These findings are discussed in relation to theories of limbic-neocortical interaction in autobiographical memory.

A unique memory process modulated by emotion underpins successful odor recognition and episodic retrieval in humans

PubMed Central

Saive, Anne-Lise; Royet, Jean-Pierre; Ravel, Nadine; Thévenet, Marc; Garcia, Samuel; Plailly, Jane

2014-01-01

We behaviorally explore the link between olfaction, emotion and memory by testing the hypothesis that the emotion carried by odors facilitates the memory of specific unique events. To investigate this idea, we used a novel behavioral approach inspired by a paradigm developed by our team to study episodic memory in a controlled and as ecological as possible way in humans. The participants freely explored three unique and rich laboratory episodes; each episode consisted of three unfamiliar odors (What) positioned at three specific locations (Where) within a visual context (Which context). During the retrieval test, which occurred 24–72 h after the encoding, odors were used to trigger the retrieval of the complex episodes. The participants were proficient in recognizing the target odors among distractors and retrieving the visuospatial context in which they were encountered. The episodic nature of the task generated high and stable memory performances, which were accompanied by faster responses and slower and deeper breathing. Successful odor recognition and episodic memory were not related to differences in odor investigation at encoding. However, memory performances were influenced by the emotional content of the odors, regardless of odor valence, with both pleasant and unpleasant odors generating higher recognition and episodic retrieval than neutral odors. Finally, the present study also suggested that when the binding between the odors and the spatio-contextual features of the episode was successful, the odor recognition and the episodic retrieval collapsed into a unique memory process that began as soon as the participants smelled the odors. PMID:24936176

Effects of level of processing but not of task enactment on recognition memory in a case of developmental amnesia.

PubMed

Gardiner, John M; Brandt, Karen R; Vargha-Khadem, Faraneh; Baddeley, Alan; Mishkin, Mortimer

2006-09-01

We report the performance in four recognition memory experiments of Jon, a young adult with early-onset developmental amnesia whose episodic memory is gravely impaired in tests of recall, but seems relatively preserved in tests of recognition, and who has developed normal levels of performance in tests of intelligence and general knowledge. Jon's recognition performance was enhanced by deeper levels of processing in comparing a more meaningful study task with a less meaningful one, but not by task enactment in comparing performance of an action with reading an action phrase. Both of these variables normally enhance episodic remembering, which Jon claimed to experience. But Jon was unable to support that claim by recollecting what it was that he remembered. Taken altogether, the findings strongly imply that Jon's recognition performance entailed little genuine episodic remembering and that the levels-of-processing effects in Jon reflected semantic, not episodic, memory.

Longitudinal Study of a Novel, Performance-based Measure of Daily Function

DTIC Science & Technology

2016-06-01

have functional impairments, and healthy age matched controls on the UPSA, as well as measures of cognition (e.g., episodic memory , semantic memory ...controls on the UPSA, as well as measures of cognition (e.g., episodic memory , semantic memory , executive function, speed). We found that patients with...diagnosis have functional impairments, and healthy age matched controls on the UPSA, as well as measures of cognition (e.g., episodic memory , semantic

A Time and Place for Everything: Developmental Differences in the Building Blocks of Episodic Memory

PubMed Central

Lee, Joshua K.; Wendelken, J. Carter; Bunge, Silvia A.; Ghetti, Simona

2015-01-01

This research investigated whether episodic memory development can be explained by improvements in relational binding processes, involved in forming novel associations between events and the context in which they occurred. Memory for item-space, item-time, and item-item relations was assessed in an ethnically diverse sample of 151 children aged 7 to 11 years and 28 young adults. Item-space memory reached adult performance by 9½ years, whereas item-time and item-item memory improved into adulthood. In path analysis, item-space, but not item-time best explained item-item memory. Across age groups, relational binding related to source memory and performance on standardized memory assessments. In conclusion, relational binding development depends on relation type, but relational binding overall supports episodic memory development. PMID:26493950

Preservation of episodic memory in semantic dementia: The importance of regions beyond the medial temporal lobes.

PubMed

Irish, Muireann; Bunk, Steffie; Tu, Sicong; Kamminga, Jody; Hodges, John R; Hornberger, Michael; Piguet, Olivier

2016-01-29

Episodic memory impairment represents one of the hallmark clinical features of patients with Alzheimer's disease (AD) attributable to the degeneration of medial temporal and parietal regions of the brain. In contrast, a somewhat paradoxical profile of relatively intact episodic memory, particularly for non-verbal material, is observed in semantic dementia (SD), despite marked atrophy of the hippocampus. This retrospective study investigated the neural substrates of episodic memory retrieval in 20 patients with a diagnosis of SD and 21 disease-matched cases of AD and compared their performance to that of 35 age- and education-matched healthy older Controls. Participants completed the Rey Complex Figure and the memory subscale of the Addenbrooke's Cognitive Examination-Revised as indices of visual and verbal episodic recall, respectively. Relative to Controls, AD patients showed compromised memory performance on both visual and verbal memory tasks. In contrast, memory deficits in SD were modality-specific occurring exclusively on the verbal task. Controlling for semantic processing ameliorated these deficits in SD, while memory impairments persisted in AD. Voxel-based morphometry analyses revealed significant overlap in the neural correlates of verbal episodic memory in AD and SD with predominantly anteromedial regions, including the bilateral hippocampus, strongly implicated. Controlling for semantic processing negated this effect in SD, however, a distributed network of frontal, medial temporal, and parietal regions was implicated in AD. Our study corroborates the view that episodic memory deficits in SD arise very largely as a consequence of the conceptual loading of traditional tasks. We propose that the functional integrity of frontal and parietal regions enables new learning to occur in SD in the face of significant hippocampal and anteromedial temporal lobe pathology, underscoring the inherent complexity of the episodic memory circuitry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Low episodic memory performance in cognitively normal elderly subjects is associated with increased posterior cingulate gray matter N-acetylaspartate: a 1H MRSI study at 7 Tesla.

PubMed

Schreiner, Simon J; Kirchner, Thomas; Wyss, Michael; Van Bergen, Jiri M G; Quevenco, Frances C; Steininger, Stefanie C; Griffith, Erica Y; Meier, Irene; Michels, Lars; Gietl, Anton F; Leh, Sandra E; Brickman, Adam M; Hock, Christoph; Nitsch, Roger M; Pruessmann, Klaas P; Henning, Anke; Unschuld, Paul G

2016-12-01

Low episodic memory performance characterizes elderly subjects at increased risk for Alzheimer's disease (AD) and may reflect neuronal dysfunction within the posterior cingulate cortex and precuneus (PCP) region. To investigate a potential association between cerebral neurometabolism and low episodic memory in the absence of cognitive impairment, tissue-specific magnetic resonance spectroscopic imaging at ultrahigh field strength of 7 Tesla was used to investigate the PCP region in a healthy elderly study population (n = 30, age 70 ± 5.7 years, Mini-Mental State Examination 29.4 ± 4.1). The Verbal Learning and Memory Test (VLMT) was administered as part of a neuropsychological battery for assessment of episodic memory performance. Significant differences between PCP gray and white matter could be observed for glutamate-glutamine (p = 0.001), choline (p = 0.01), and myo-inositol (p = 0.02). Low Verbal Learning and Memory Test performance was associated with high N-acetylaspartate in PCP gray matter (p = 0.01) but not in PCP white matter. Our data suggest that subtle decreases in episodic memory performance in the elderly may be associated with increased levels of N-acetylaspartate as a reflection of increased mitochondrial energy capacity in PCP gray matter. Copyright © 2016 Elsevier Inc. All rights reserved.

Study of metamemory in patients with chronic alcoholism using a feeling-of-knowing episodic memory task.

PubMed

Le Berre, Anne-Pascale; Pinon, Karine; Vabret, François; Pitel, Anne-Lise; Allain, Philippe; Eustache, Francis; Beaunieux, Hélène

2010-11-01

Alcoholism affects various cognitive processes, including components of memory. Metamemory, though of particular interest for patient treatment, has not yet been extensively investigated.  A feeling-of-knowing (FOK) measure of metamemory was administered to 28 alcoholic patients and 28 healthy controls during an episodic memory task including the learning of 20 pairs of items, followed by a 20-minute delayed recall and a recognition task. Prior to recognition, participants rated their ability to recognize each nonrecalled word among 4 items. This episodic FOK measure served to compare predictions of future recognition performance and actual recognition performance. Furthermore, a subjective measure of metamemory, the Metamemory In Adulthood (MIA) questionnaire, was completed by patients and controls. This assessment of alcoholic patients' metamemory profile was accompanied by an evaluation of episodic memory and executive functioning. FOK results revealed deficits in accuracy, with the alcoholic patients providing overestimations. There were also links between FOK inaccuracy, executive decline, and episodic memory impairment in patients. MIA results showed that although alcoholics did display memory difficulties, they did not differ from controls on questions about memory capacity. Chronic alcoholism affects both episodic memory and metamemory for novel information. Patients were relatively unaware of their memory deficits and believed that their memory was as good as that of the healthy controls. The monitoring measure (FOK) and the subjective measure of metamemory (MIA) showed that patients with chronic alcoholism overestimated their memory capacities. Episodic memory deficit and executive dysfunction would explain metamemory decline in this clinical population. Copyright © 2010 by the Research Society on Alcoholism.

Age-related changes in parietal lobe activation during an episodic memory retrieval task.

PubMed

Oedekoven, Christiane S H; Jansen, Andreas; Kircher, Tilo T; Leube, Dirk T

2013-05-01

The crucial role of lateral parietal regions in episodic memory has been confirmed in previous studies. While aging has an influence on retrieval of episodic memory, it remains to be examined how the involvement of lateral parietal regions in episodic memory changes with age. We investigated episodic memory retrieval in two age groups, using faces as stimuli and retrieval success as a measure of episodic memory. Young and elderly participants showed activation within a similar network, including lateral and medial parietal as well as prefrontal regions, but elderly showed a higher level of brain activation regardless of condition. Furthermore, we examined functional connectivity in the two age groups and found a more extensive network in the young group, including correlations of parietal and prefrontal regions. In the elderly, the overall stronger activation related to memory performance may indicate a compensatory process for a less extensive functional network.

Benefits and Costs of Context Reinstatement in Episodic Memory: An ERP Study.

PubMed

Bramão, Inês; Johansson, Mikael

2017-01-01

This study investigated context-dependent episodic memory retrieval. An influential idea in the memory literature is that performance benefits when the retrieval context overlaps with the original encoding context. However, such memory facilitation may not be driven by the encoding-retrieval overlap per se but by the presence of diagnostic features in the reinstated context that discriminate the target episode from competing episodes. To test this prediction, the encoding-retrieval overlap and the diagnostic value of the context were manipulated in a novel associative recognition memory task. Participants were asked to memorize word pairs presented together with diagnostic (unique) and nondiagnostic (shared) background scenes. At test, participants recognized the word pairs in the presence and absence of the previously encoded contexts. Behavioral data show facilitated memory performance in the presence of the original context but, importantly, only when the context was diagnostic of the target episode. The electrophysiological data reveal an early anterior ERP encoding-retrieval overlap effect that tracks the cost associated with having nondiagnostic contexts present at retrieval, that is, shared by multiple previous episodes, and a later posterior encoding-retrieval overlap effect that reflects facilitated access to the target episode during retrieval in diagnostic contexts. Taken together, our results underscore the importance of the diagnostic value of the context and suggest that context-dependent episodic memory effects are multiple determined.

Computational dissection of human episodic memory reveals mental process-specific genetic profiles

PubMed Central

Luksys, Gediminas; Fastenrath, Matthias; Coynel, David; Freytag, Virginie; Gschwind, Leo; Heck, Angela; Jessen, Frank; Maier, Wolfgang; Milnik, Annette; Riedel-Heller, Steffi G.; Scherer, Martin; Spalek, Klara; Vogler, Christian; Wagner, Michael; Wolfsgruber, Steffen; Papassotiropoulos, Andreas; de Quervain, Dominique J.-F.

2015-01-01

Episodic memory performance is the result of distinct mental processes, such as learning, memory maintenance, and emotional modulation of memory strength. Such processes can be effectively dissociated using computational models. Here we performed gene set enrichment analyses of model parameters estimated from the episodic memory performance of 1,765 healthy young adults. We report robust and replicated associations of the amine compound SLC (solute-carrier) transporters gene set with the learning rate, of the collagen formation and transmembrane receptor protein tyrosine kinase activity gene sets with the modulation of memory strength by negative emotional arousal, and of the L1 cell adhesion molecule (L1CAM) interactions gene set with the repetition-based memory improvement. Furthermore, in a large functional MRI sample of 795 subjects we found that the association between L1CAM interactions and memory maintenance revealed large clusters of differences in brain activity in frontal cortical areas. Our findings provide converging evidence that distinct genetic profiles underlie specific mental processes of human episodic memory. They also provide empirical support to previous theoretical and neurobiological studies linking specific neuromodulators to the learning rate and linking neural cell adhesion molecules to memory maintenance. Furthermore, our study suggests additional memory-related genetic pathways, which may contribute to a better understanding of the neurobiology of human memory. PMID:26261317

Computational dissection of human episodic memory reveals mental process-specific genetic profiles.

PubMed

Luksys, Gediminas; Fastenrath, Matthias; Coynel, David; Freytag, Virginie; Gschwind, Leo; Heck, Angela; Jessen, Frank; Maier, Wolfgang; Milnik, Annette; Riedel-Heller, Steffi G; Scherer, Martin; Spalek, Klara; Vogler, Christian; Wagner, Michael; Wolfsgruber, Steffen; Papassotiropoulos, Andreas; de Quervain, Dominique J-F

2015-09-01

Episodic memory performance is the result of distinct mental processes, such as learning, memory maintenance, and emotional modulation of memory strength. Such processes can be effectively dissociated using computational models. Here we performed gene set enrichment analyses of model parameters estimated from the episodic memory performance of 1,765 healthy young adults. We report robust and replicated associations of the amine compound SLC (solute-carrier) transporters gene set with the learning rate, of the collagen formation and transmembrane receptor protein tyrosine kinase activity gene sets with the modulation of memory strength by negative emotional arousal, and of the L1 cell adhesion molecule (L1CAM) interactions gene set with the repetition-based memory improvement. Furthermore, in a large functional MRI sample of 795 subjects we found that the association between L1CAM interactions and memory maintenance revealed large clusters of differences in brain activity in frontal cortical areas. Our findings provide converging evidence that distinct genetic profiles underlie specific mental processes of human episodic memory. They also provide empirical support to previous theoretical and neurobiological studies linking specific neuromodulators to the learning rate and linking neural cell adhesion molecules to memory maintenance. Furthermore, our study suggests additional memory-related genetic pathways, which may contribute to a better understanding of the neurobiology of human memory.

Preschool children's proto-episodic memory assessed by deferred imitation.

PubMed

Burns, Patrick; Russell, Charlotte; Russell, James

2015-01-01

In two experiments, both employing deferred imitation, we studied the developmental origins of episodic memory in two- to three-year-old children by adopting a "minimalist" view of episodic memory based on its What-When-Where ("WWW": spatiotemporal plus semantic) content. We argued that the temporal element within spatiotemporal should be the order/simultaneity of the event elements, but that it is not clear whether the spatial content should be egocentric or allocentric. We also argued that episodic recollection should be configural (tending towards all-or-nothing recall of the WWW elements). Our first deferred imitation experiment, using a two-dimensional (2D) display, produced superior-to-chance performance after 2.5 years but no evidence of configural memory. Moreover, performance did not differ from that on a What-What-What control task. Our second deferred imitation study required the children to reproduce actions on an object in a room, thereby affording layout-based spatial cues. In this case, not only was there superior-to-chance performance after 2.5 years but memory was also configural at both ages. We discuss the importance of allocentric spatial cues in episodic recall in early proto-episodic memory and reflect on the possible role of hippocampal development in this process.

Adaptive scaling of reward in episodic memory: a replication study.

PubMed

Mason, Alice; Ludwig, Casimir; Farrell, Simon

2017-11-01

Reward is thought to enhance episodic memory formation via dopaminergic consolidation. Bunzeck, Dayan, Dolan, and Duzel [(2010). A common mechanism for adaptive scaling of reward and novelty. Human Brain Mapping, 31, 1380-1394] provided functional magnetic resonance imaging (fMRI) and behavioural evidence that reward and episodic memory systems are sensitive to the contextual value of a reward-whether it is relatively higher or lower-as opposed to absolute value or prediction error. We carried out a direct replication of their behavioural study and did not replicate their finding that memory performance associated with reward follows this pattern of adaptive scaling. An effect of reward outcome was in the opposite direction to that in the original study, with lower reward outcomes leading to better memory than higher outcomes. There was a marginal effect of reward context, suggesting that expected value affected memory performance. We discuss the robustness of the reward memory relationship to variations in reward context, and whether other reward-related factors have a more reliable influence on episodic memory.

Memory functions in chronic pain: examining contributions of attention and age to test performance.

PubMed

Oosterman, Joukje M; Derksen, Laura C; van Wijck, Albert J M; Veldhuijzen, Dieuwke S; Kessels, Roy P C

2011-01-01

Previous studies have revealed that memory performance is diminished in chronic pain patients. Few studies, however, have assessed multiple components of memory in a single sample. It is currently also unknown whether attentional problems, which are commonly observed in chronic pain, mediate the decline in memory. Finally, previous studies have focused on middle-aged adults, and a possible detrimental effect of aging on memory performance in chronic pain patients has been commonly disregarded. This study, therefore, aimed at describing the pattern of semantic, working, and visual and verbal episodic memory performance in participants with chronic pain, while testing for possible contributions of attention and age to task performance. Thirty-four participants with chronic pain and 32 pain-free participants completed tests of episodic, semantic, and working memory to assess memory performance and a test of attention. Participants with chronic pain performed worse on tests of working memory and verbal episodic memory. A decline in attention explained some, but not all, group differences in memory performance. Finally, no additional effect of age on the diminished task performance in participants with chronic pain was observed. Taken together, the results indicate that chronic pain significantly affects memory performance. Part of this effect may be caused by underlying attentional dysfunction, although this could not fully explain the observed memory decline. An increase in age in combination with the presence of chronic pain did not additionally affect memory performance.

Spatial and Temporal Episodic Memory Retrieval Recruit Dissociable Functional Networks in the Human Brain

ERIC Educational Resources Information Center

Ekstrom, Arne D.; Bookheimer, Susan Y.

2007-01-01

Imaging, electrophysiological studies, and lesion work have shown that the medial temporal lobe (MTL) is important for episodic memory; however, it is unclear whether different MTL regions support the spatial, temporal, and item elements of episodic memory. In this study we used fMRI to examine retrieval performance emphasizing different aspects…

Cardiorespiratory Fitness Is Associated With Cognitive Performance in Older But Not Younger Adults.

PubMed

Hayes, Scott M; Forman, Daniel E; Verfaellie, Mieke

2016-05-01

Aging is associated with declines in executive function and episodic memory. Cardiorespiratory fitness (CRF) has been associated with enhanced executive function in older adults (OA), but the relationship with episodic memory remains unclear. The purpose of the study was to examine the relationship between CRF and cognition in young and OA and whether CRF mitigates age-related cognitive decline. Participants completed exercise testing to evaluate CRF (peak VO2) and neuropsychological testing to assess cognition. In OA, peak VO2 was positively related to executive function, as well as to accuracy on an experimental face-name memory task and visual episodic memory. In young adults (YA), a relationship between peak VO2 and cognition was not evident. High-fit OA performed as well as YA on executive function measures. On episodic memory measures, YA performed better than high-fit OA, who in turn performed better than low-fit OA. CRF is positively associated with executive function and episodic memory in OA and attenuates age-related cognitive decline. We provide preliminary support for the age-dependence hypothesis, which posits that cognition and CRF relationships may be most readily observed during lifetime periods of significant neurocognitive development. Published by Oxford University Press on behalf of the Gerontological Society of America 2014.

Decomposing the relationship between cognitive functioning and self-referent memory beliefs in older adulthood: What’s memory got to do with it?

PubMed Central

Payne, Brennan R.; Gross, Alden L.; Hill, Patrick L.; Parisi, Jeanine M.; Rebok, George W.; Stine-Morrow, Elizabeth A. L.

2018-01-01

With advancing age, episodic memory performance shows marked declines along with concurrent reports of lower subjective memory beliefs. Given that normative age-related declines in episodic memory co-occur with declines in other cognitive domains, we examined the relationship between memory beliefs and multiple domains of cognitive functioning. Confirmatory bi-factor structural equation models were used to parse the shared and independent variance among factors representing episodic memory, psychomotor speed, and executive reasoning in one large cohort study (Senior Odyssey, N = 462), and replicated using another large cohort of healthy older adults (ACTIVE, N = 2,802). Accounting for a general fluid cognitive functioning factor (comprised of the shared variance among measures of episodic memory, speed, and reasoning) attenuated the relationship between objective memory performance and subjective memory beliefs in both samples. Moreover, the general cognitive functioning factor was the strongest predictor of memory beliefs in both samples. These findings are consistent with the notion that dispositional memory beliefs may reflect perceptions of cognition more broadly. This may be one reason why memory beliefs have broad predictive validity for interventions that target fluid cognitive ability. PMID:27685541

Decomposing the relationship between cognitive functioning and self-referent memory beliefs in older adulthood: what's memory got to do with it?

PubMed

Payne, Brennan R; Gross, Alden L; Hill, Patrick L; Parisi, Jeanine M; Rebok, George W; Stine-Morrow, Elizabeth A L

2017-07-01

With advancing age, episodic memory performance shows marked declines along with concurrent reports of lower subjective memory beliefs. Given that normative age-related declines in episodic memory co-occur with declines in other cognitive domains, we examined the relationship between memory beliefs and multiple domains of cognitive functioning. Confirmatory bi-factor structural equation models were used to parse the shared and independent variance among factors representing episodic memory, psychomotor speed, and executive reasoning in one large cohort study (Senior Odyssey, N = 462), and replicated using another large cohort of healthy older adults (ACTIVE, N = 2802). Accounting for a general fluid cognitive functioning factor (comprised of the shared variance among measures of episodic memory, speed, and reasoning) attenuated the relationship between objective memory performance and subjective memory beliefs in both samples. Moreover, the general cognitive functioning factor was the strongest predictor of memory beliefs in both samples. These findings are consistent with the notion that dispositional memory beliefs may reflect perceptions of cognition more broadly. This may be one reason why memory beliefs have broad predictive validity for interventions that target fluid cognitive ability.

Aging, Estrogens, and Episodic Memory in Women

PubMed Central

Henderson, Victor W.

2009-01-01

Objective To review the relation in midlife and beyond between estrogen exposures and episodic memory in women. Background Episodic memory performance declines with usual aging, and impairments in episodic memory often portend the development of Alzheimer's disease. In the laboratory, estradiol influences hippocampal function and animal learning. However, it is controversial whether estrogens affect memory after a woman's reproductive years. Method Focused literature review, including a summary of a systematic search of clinical trials of estrogens in which outcomes included an objective measure of episodic memory. Results The natural menopause transition is not associated with objective changes in episodic memory. Strong clinical trial evidence indicates that initiating estrogen-containing hormone therapy after about age 60 years does not benefit episodic memory. Clinical trial findings in middle-age women before age 60 are limited by smaller sample sizes and shorter treatment durations, but these also do not indicate substantial memory effects. Limited short-term evidence, however, suggests that estrogens may improve verbal memory after surgical menopause. Although hormone therapy initiation in old age increases dementia risk, observational studies raise the question of an early critical window during which midlife estrogen therapy reduces late-life Alzheimer's disease. However, almost no data address whether midlife estrogen therapy affects episodic memory in old age. Conclusions Episodic memory is not substantially impacted by the natural menopause transition or improved by use of estrogen-containing hormone therapy after age 60. Further research is needed to determine whether outcomes differ after surgical menopause or whether episodic memory later in life is modified by midlife estrogenic exposures. PMID:19996872

Episodic memory deficits slow down the dynamics of cognitive procedural learning in normal ageing

PubMed Central

Beaunieux, Hélène; Hubert, Valérie; Pitel, Anne Lise; Desgranges, Béatrice; Eustache, Francis

2009-01-01

Cognitive procedural learning is characterized by three phases, each involving distinct processes. Considering the implication of the episodic memory in the first cognitive stage, the impairment of this memory system might be responsible for a slowing down of the cognitive procedural learning dynamics in the course of aging. Performances of massed cognitive procedural learning were evaluated in older and younger participants using the Tower of Toronto task. Nonverbal intelligence and psychomotor abilities were used to analyze procedural dynamics, while episodic memory and working memory were assessed to measure their respective contributions to learning strategies. This experiment showed that older participants did not spontaneously invoke episodic memory and presented a slowdown in the cognitive procedural learning associated with a late involvement of working memory. These findings suggest that the slowdown in the cognitive procedural learning may be linked with the implementation of different learning strategies less involving episodic memory in older subjects. PMID:18654928

Olfactory memory in the old and very old: relations to episodic and semantic memory and APOE genotype.

PubMed

Larsson, Maria; Hedner, Margareta; Papenberg, Goran; Seubert, Janina; Bäckman, Lars; Laukka, Erika J

2016-02-01

The neuroanatomical organization that underlies olfactory memory is different from that of other memory types. The present work examines olfactory memory in an elderly population-based sample (Swedish National Study on Aging and Care in Kungsholmen) aged 60-100 years (n = 2280). We used structural equation modeling to investigate whether olfactory memory in old age is best conceptualized as a distinct category, differentiated from episodic and semantic memory. Further, potential olfactory dedifferentiation and genetic associations (APOE) to olfactory function in late senescence were investigated. Results are in support of a 3-factor solution where olfactory memory, as indexed by episodic odor recognition and odor identification, is modeled separately from episodic and semantic memory for visual and verbal information. Increasing age was associated with poorer olfactory memory performance, and observed age-related deficits were further exacerbated for carriers of the APOE ε4 allele; these effects tended to be larger for olfactory memory compared to episodic and semantic memory pertaining to other sensory systems (vision, auditory). Finally, stronger correlations between olfactory and episodic memory, indicating dedifferentiation, were observed in the older age groups. Copyright © 2016 Elsevier Inc. All rights reserved.

Episodic memory function is associated with multiple measures of white matter integrity in cognitive aging

PubMed Central

Lockhart, Samuel N.; Mayda, Adriane B. V.; Roach, Alexandra E.; Fletcher, Evan; Carmichael, Owen; Maillard, Pauline; Schwarz, Christopher G.; Yonelinas, Andrew P.; Ranganath, Charan; DeCarli, Charles

2011-01-01

Previous neuroimaging research indicates that white matter injury and integrity, measured respectively by white matter hyperintensities (WMH) and fractional anisotropy (FA) obtained from diffusion tensor imaging (DTI), differ with aging and cerebrovascular disease (CVD) and are associated with episodic memory deficits in cognitively normal older adults. However, knowledge about tract-specific relationships between WMH, FA, and episodic memory in aging remains limited. We hypothesized that white matter connections between frontal cortex and subcortical structures as well as connections between frontal and temporo-parietal cortex would be most affected. In the current study, we examined relationships between WMH, FA and episodic memory in 15 young adults, 13 elders with minimal WMH and 15 elders with extensive WMH, using an episodic recognition memory test for object-color associations. Voxel-based statistics were used to identify voxel clusters where white matter measures were specifically associated with variations in episodic memory performance, and white matter tracts intersecting these clusters were analyzed to examine white matter-memory relationships. White matter injury and integrity measures were significantly associated with episodic memory in extensive regions of white matter, located predominantly in frontal, parietal, and subcortical regions. Template based tractography indicated that white matter injury, as measured by WMH, in the uncinate and inferior longitudinal fasciculi were significantly negatively associated with episodic memory performance. Other tracts such as thalamo-frontal projections, superior longitudinal fasciculus, and dorsal cingulum bundle demonstrated strong negative associations as well. The results suggest that white matter injury to multiple pathways, including connections of frontal and temporal cortex and frontal-subcortical white matter tracts, plays a critical role in memory differences seen in older individuals. PMID:22438841

Examination of the bidirectional influences of leisure activity and memory in old people: a dissociative effect on episodic memory.

PubMed

Mousavi-Nasab, S-M-Hossein; Kormi-Nouri, Reza; Nilsson, Lars-Göran

2014-08-01

The present study examined the relationships between different types of social and cognitive activities and different types of episodic and semantic memory. A total of 794 adult men and women from five age cohorts (aged 65-85 at baseline), participating in the longitudinal Betula project on ageing, memory, and health, were included in the study. The participants were studied over 10 years (1995-2005) in three waves. Recognition and recall were used as episodic memory tasks, and knowledge and verbal fluency as semantic memory tasks. The results, after controlling for age, gender, education, and some diseases, including heart disease and hypertension, as covariates, showed unidirectional effects of social activity on episodic memory on all test occasions (β = .10). Also, episodic memory predicted change in cognitive activity for all test waves (β = .21-.22). Findings suggest that social activity can be seen as protective factor against memory decline. It also seems that episodic memory performance is a predictor of cognitive activity in old people. However, the opposite direction does not hold true. © 2013 The British Psychological Society.

Glycated haemoglobin (HbA1c), diabetes and trajectories of change in episodic memory performance.

PubMed

Pappas, Colleen; Andel, Ross; Infurna, Frank J; Seetharaman, Shyam

2017-02-01

As the ageing population grows, it is important to identify strategies to moderate cognitive ageing. We examined glycated haemoglobin (HbA1c) and diabetes in relation to level and change in episodic memory in older adults with and without diabetes. Data from 4419 older adults with (n=950) and without (n=3469) diabetes participating in a nationally representative longitudinal panel study (the Health and Retirement Study) were examined. Average baseline age was 72.66 years and 58% were women. HbA1c was measured in 2006 and episodic memory was measured using immediate and delayed list recall over 4 biennial waves between 2006 and 2012. Growth curve models were used to assess trajectories of episodic memory change. In growth curve models adjusted for age, sex, education, race, depressive symptoms and waist circumference, higher HbA1c levels and having diabetes were associated with poorer baseline episodic memory (p=0.036 and <0.001, respectively) and greater episodic memory decline (p=0.006 and 0.004, respectively). The effect of HbA1c on episodic memory decline was smaller than the effect of age. The results were stronger for women than men and were not modified by age or race. When the main analyses were estimated for those with and without diabetes separately, HbA1c was significantly linked to change in episodic memory only among those with diabetes. Higher HbA1c and diabetes were both associated with declines in episodic memory, with this relationship further exacerbated by having diabetes and elevated HbA1c. HbA1c appeared more important for episodic memory performance among women than men. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Long-term consolidation of declarative memory: insight from temporal lobe epilepsy.

PubMed

Tramoni, Eve; Felician, Olivier; Barbeau, Emmanuel J; Guedj, Eric; Guye, Maxime; Bartolomei, Fabrice; Ceccaldi, Mathieu

2011-03-01

Several experiments carried out with a subset of patients with temporal lobe epilepsy have demonstrated normal memory performance at standard delays of recall (i.e. minutes to hours) but impaired performance over longer delays (i.e. days or weeks), suggesting altered long-term consolidation mechanisms. These mechanisms were specifically investigated in a group of five adult-onset pharmaco-sensitive patients with temporal lobe epilepsy, exhibiting severe episodic memory complaints despite normal performance at standardized memory assessment. In a first experiment, the magnitude of autobiographical memory loss was evaluated using retrograde personal memory tasks based on verbal and visual cues. In both conditions, results showed an unusual U-shaped pattern of personal memory impairment, encompassing most of the patients' life, sparing however, periods of the childhood, early adulthood and past several weeks. This profile was suggestive of a long-term consolidation impairment of personal episodes, adequately consolidated over 'short-term' delays but gradually forgotten thereafter. Therefore, in a subsequent experiment, patients were submitted to a protocol specifically devised to investigate short and long-term consolidation of contextually-bound experiences (episodic memory) and context-free information (semantic knowledge and single-items). In the short term (1 h), performance at both contextually-free and contextually-bound memory tasks was intact. After a 6-week delay, however, contextually-bound memory performance was impaired while contextually-free memory performance remained preserved. This effect was independent of task difficulty and the modality of retrieval (recall and recognition). Neuroimaging studies revealed the presence of mild metabolic changes within medial temporal lobe structures. Taken together, these results show the existence of different consolidation systems within declarative memory. They suggest that mild medial temporal lobe dysfunction can impede the building and stabilization of episodic memories but leaves long-term semantic and single-items mnemonic traces intact.

Metamemory in children with autism: exploring "feeling-of-knowing" in episodic and semantic memory.

PubMed

Wojcik, Dominika Z; Moulin, Chris J A; Souchay, Celine

2013-01-01

Autism spectrum disorder (ASD) is a neurodevelopmental disorder primarily affecting social function and communication. Recently, there has been an interest in whether people with ASD also show memory deficits. Studies in ASD have revealed subtle impairments on tasks requiring participants to learn new information (episodic memory), but intact performance on general knowledge tasks (semantic memory). The novelty of this study was to explore metamemory (i.e., awareness of memory performance) and to examine whether children with ASD suffer from a generalized metamemory deficit common to all forms of memory, or would only present deficits on episodic metamemory tasks. To assess metamemory functioning we administered 2 feeling-of-knowing (FOK) tasks, 1 for episodic and 1 for semantic materials. In these tasks, participants are asked to predict the likelihood of subsequently recognizing currently unrecalled information. It was found that children with autism made inaccurate FOK predictions, but only for episodic materials. A specific deficit in meta-cognition emerges for only one set of materials. We argue that this deficit can be conceived of as reflecting a deficit in recollection, stemming from an inability to cast the self in the past and retrieve information about the study episode.

Better imagined: Neural correlates of the episodic simulation boost to prospective memory performance.

PubMed

Spreng, R Nathan; Madore, Kevin P; Schacter, Daniel L

2018-05-01

Episodic simulation is an adaptive process that can support goal-directed activity and planning success. We investigated the neural architecture associated with the episodic simulation improvement to the likelihood of carrying out future actions by isolating the brain regions associated with this facilitation in a prospective memory paradigm. Participants performed a lexical decision task by making word/non-word judgments, with rarely occurring prospective memory target words requiring a pre-specified manual response. Prior to scanning, participants were given exposure to two lists of prospective memory targets: animals and tools. In a fully counterbalanced design, participants generated a rhyme to one target list and imagined their subsequent encounter (episodic simulation) with target words on the other list. Replicating prior behavioral work, episodic simulation improved subsequent prospective memory performance. Brain activation was assessed in a multivariate partial least squares analysis. Relative to lexical decision blocks with no prospective memory demand, sustained prospective memory replicated prior observations of frontal polar activation. Critically, maintaining the intention to respond to simulated targets, over and above rhyme targets, engaged middle frontal and angular gyri, and medial parietal and prefrontal cortices. Transient activity associated with prospective memory target hits revealed activation for simulated targets in medial prefrontal cortex, posterior cingulate, lateral temporal lobe and inferior parietal lobule. In contrast, rhyme target hits engaged more left lateralized dorsolateral prefrontal cortex and anterior insula. Episodic simulation, thus effectively shifts executive control strategy and boosts task performance. These results are consistent with a growing body of evidence implicating executive control and default network region interactions in adaptive, goal-directed behavior. Copyright © 2018 Elsevier Ltd. All rights reserved.

Changes in sleep theta rhythm are related to episodic memory impairment in early Alzheimer's disease.

PubMed

Hot, Pascal; Rauchs, Géraldine; Bertran, Françoise; Denise, Pierre; Desgranges, Béatrice; Clochon, Patrice; Eustache, Francis

2011-07-01

Impairments have been reported both in sleep structure and episodic memory in Alzheimer's disease [AD]. Our objective was to investigate the relationships between episodic memory deficits and electro-encephalography [EEG] abnormalities occurring during sleep in patients with early AD. Postlearning sleep was recorded in 14 patients with mild to moderate AD, and 14 healthy elderly controls after they performed an episodic memory task derived from the Grober and Buschke's procedure. For each sleep stage, the relative power and mean frequency in each band were analyzed. Relative to agematched controls, AD patients presented faster mean theta frequency in both REM sleep and slow wave sleep [SWS]. In AD patients, a correlative analysis revealed that faster theta frequency during SWS was associated with better delayed episodic recall. We assume that increased theta activity reflects changes in neuronal activity to maintain memory performance, indicating that compensatory mechanisms already described at the waking state could also be engaged during SWS. Copyright © 2011 Elsevier B.V. All rights reserved.

Episodic Memory, Semantic Memory, and Fluency.

ERIC Educational Resources Information Center

Schaefer, Carl F.

1980-01-01

Suggests that creating a second-language semantic network can be conceived as developing a plan for retrieving second-language word forms. Characteristics of linguistic performance which will promote fluency are discussed in light of the distinction between episodic and semantic memory. (AMH)

A Potential Spatial Working Memory Training Task to Improve Both Episodic Memory and Fluid Intelligence

PubMed Central

Rudebeck, Sarah R.; Bor, Daniel; Ormond, Angharad; O’Reilly, Jill X.; Lee, Andy C. H.

2012-01-01

One current challenge in cognitive training is to create a training regime that benefits multiple cognitive domains, including episodic memory, without relying on a large battery of tasks, which can be time-consuming and difficult to learn. By giving careful consideration to the neural correlates underlying episodic and working memory, we devised a computerized working memory training task in which neurologically healthy participants were required to monitor and detect repetitions in two streams of spatial information (spatial location and scene identity) presented simultaneously (i.e. a dual n-back paradigm). Participants’ episodic memory abilities were assessed before and after training using two object and scene recognition memory tasks incorporating memory confidence judgments. Furthermore, to determine the generalizability of the effects of training, we also assessed fluid intelligence using a matrix reasoning task. By examining the difference between pre- and post-training performance (i.e. gain scores), we found that the trainers, compared to non-trainers, exhibited a significant improvement in fluid intelligence after 20 days. Interestingly, pre-training fluid intelligence performance, but not training task improvement, was a significant predictor of post-training fluid intelligence improvement, with lower pre-training fluid intelligence associated with greater post-training gain. Crucially, trainers who improved the most on the training task also showed an improvement in recognition memory as captured by d-prime scores and estimates of recollection and familiarity memory. Training task improvement was a significant predictor of gains in recognition and familiarity memory performance, with greater training improvement leading to more marked gains. In contrast, lower pre-training recollection memory scores, and not training task improvement, led to greater recollection memory performance after training. Our findings demonstrate that practice on a single working memory task can potentially improve aspects of both episodic memory and fluid intelligence, and that an extensive training regime with multiple tasks may not be necessary. PMID:23209740

A potential spatial working memory training task to improve both episodic memory and fluid intelligence.

PubMed

Rudebeck, Sarah R; Bor, Daniel; Ormond, Angharad; O'Reilly, Jill X; Lee, Andy C H

2012-01-01

One current challenge in cognitive training is to create a training regime that benefits multiple cognitive domains, including episodic memory, without relying on a large battery of tasks, which can be time-consuming and difficult to learn. By giving careful consideration to the neural correlates underlying episodic and working memory, we devised a computerized working memory training task in which neurologically healthy participants were required to monitor and detect repetitions in two streams of spatial information (spatial location and scene identity) presented simultaneously (i.e. a dual n-back paradigm). Participants' episodic memory abilities were assessed before and after training using two object and scene recognition memory tasks incorporating memory confidence judgments. Furthermore, to determine the generalizability of the effects of training, we also assessed fluid intelligence using a matrix reasoning task. By examining the difference between pre- and post-training performance (i.e. gain scores), we found that the trainers, compared to non-trainers, exhibited a significant improvement in fluid intelligence after 20 days. Interestingly, pre-training fluid intelligence performance, but not training task improvement, was a significant predictor of post-training fluid intelligence improvement, with lower pre-training fluid intelligence associated with greater post-training gain. Crucially, trainers who improved the most on the training task also showed an improvement in recognition memory as captured by d-prime scores and estimates of recollection and familiarity memory. Training task improvement was a significant predictor of gains in recognition and familiarity memory performance, with greater training improvement leading to more marked gains. In contrast, lower pre-training recollection memory scores, and not training task improvement, led to greater recollection memory performance after training. Our findings demonstrate that practice on a single working memory task can potentially improve aspects of both episodic memory and fluid intelligence, and that an extensive training regime with multiple tasks may not be necessary.

The six blind men and the elephant: Are episodic memory tasks tests of different things or different tests of the same thing?

PubMed

Cheke, Lucy G; Clayton, Nicola S

2015-09-01

The development of episodic memory in children has been of interest to researchers for more than a century. Current behavioral tests that have been developed to assess episodic memory differ substantially in their surface features. Therefore, it is possible that these tests are assessing different memory processes. In this study, 106 children aged 3 to 6 years were tested on four putative tests of episodic memory. Covariation in performance was investigated in order to address two conflicting hypotheses: (a) that the high level of difference between the tests will result in little covariation in performance despite their being designed to assess the same ability and (b) that the conceptual similarity of these tasks will lead to high levels of covariation despite surface differences. The results indicated a gradual improvement with age on all tests. Performances on many of the tests were related, but not after controlling for age. A principal component analysis found that a single principal component was able to satisfactorily fit the observed data. This principal component produced a marginally stronger correlation with age than any test alone. As such, it might be concluded that different tests of episodic memory are too different to be used in parallel. Nevertheless, if used together, these tests may offer a robust assessment of episodic memory as a complex multifaceted process. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Neural dynamics associated with semantic and episodic memory for faces: evidence from multiple frequency bands.

PubMed

Zion-Golumbic, Elana; Kutas, Marta; Bentin, Shlomo

2010-02-01

Prior semantic knowledge facilitates episodic recognition memory for faces. To examine the neural manifestation of the interplay between semantic and episodic memory, we investigated neuroelectric dynamics during the creation (study) and the retrieval (test) of episodic memories for famous and nonfamous faces. Episodic memory effects were evident in several EEG frequency bands: theta (4-8 Hz), alpha (9-13 Hz), and gamma (40-100 Hz). Activity in these bands was differentially modulated by preexisting semantic knowledge and by episodic memory, implicating their different functional roles in memory. More specifically, theta activity and alpha suppression were larger for old compared to new faces at test regardless of fame, but were both larger for famous faces during study. This pattern of selective semantic effects suggests that the theta and alpha responses, which are primarily associated with episodic memory, reflect utilization of semantic information only when it is beneficial for task performance. In contrast, gamma activity decreased between the first (study) and second (test) presentation of a face, but overall was larger for famous than nonfamous faces. Hence, the gamma rhythm seems to be primarily related to activation of preexisting neural representations that may contribute to the formation of new episodic traces. Taken together, these data provide new insights into the complex interaction between semantic and episodic memory for faces and the neural dynamics associated with mnemonic processes.

Working memory binding and episodic memory formation in aging, mild cognitive impairment, and Alzheimer's dementia.

PubMed

van Geldorp, Bonnie; Heringa, Sophie M; van den Berg, Esther; Olde Rikkert, Marcel G M; Biessels, Geert Jan; Kessels, Roy P C

2015-01-01

Recent studies indicate that in both normal and pathological aging working memory (WM) performance deteriorates, especially when associations have to be maintained. However, most studies typically do not assess the relationship between WM and episodic memory formation. In the present study, we examined WM and episodic memory formation in normal aging and in patients with early Alzheimer's disease (mild cognitive impairment, MCI; and Alzheimer's dementia, AD). In the first study, 26 young adults (mean age 29.6 years) were compared to 18 middle-aged adults (mean age 52.2 years) and 25 older adults (mean age 72.8 years). We used an associative delayed-match-to-sample WM task, which requires participants to maintain two pairs of faces and houses presented on a computer screen for short (3 s) or long (6 s) maintenance intervals. After the WM task, an unexpected subsequent associative memory task was administered (two-alternative forced choice). In the second study, 27 patients with AD and 19 patients with MCI were compared to 25 older controls, using the same paradigm as that in Experiment 1. Older adults performed worse than both middle-aged and young adults. No effect of delay was observed in the healthy adults, and pairs that were processed during long maintenance intervals were not better remembered in the subsequent memory task. In the MCI and AD patients, longer maintenance intervals hampered the task performance. Also, both patient groups performed significantly worse than controls on the episodic memory task as well as the associative WM task. Aging and AD present with a decline in WM binding, a finding that extends similar results in episodic memory. Longer delays in the WM task did not affect episodic memory formation. We conclude that WM deficits are found when WM capacity is exceeded, which may occur during associative processing.

Brain structural, functional, and cognitive correlates of recent versus remote autobiographical memories in amnestic Mild Cognitive Impairment

PubMed Central

Tomadesso, Clémence; Perrotin, Audrey; Mutlu, Justine; Mézenge, Florence; Landeau, Brigitte; Egret, Stéphanie; de la Sayette, Vincent; Jonin, Pierre-Yves; Eustache, Francis; Desgranges, Béatrice; Chételat, Gaël

2015-01-01

Deficits in autobiographical memory appear earlier for recent than for remote life periods over the course of Alzheimer's disease (AD). The present study aims to further our understanding of this graded effect by investigating the cognitive and neural substrates of recent versus remote autobiographical memories in patients with amnestic Mild Cognitive Impairment (aMCI) thanks to an autobiographical fluency task. 20 aMCI patients and 25 Healthy elderly Controls (HC) underwent neuropsychological tests assessing remote (20-to-30 years old) and recent (the ten last years) autobiographical memory as well as episodic and semantic memory, executive function and global cognition. All patients also had a structural MRI and an FDG-PET scan. Correlations were assessed between each autobiographical memory score and the other tests as well as grey matter volume and metabolism. Within the aMCI, performances for the remote period correlated with personal semantic memory and episodic memory retrieval whereas performances for the recent period only correlated with episodic memory retrieval. Neuroimaging analyses revealed significant correlations between performances for the remote period and temporal pole and temporo-parietal cortex volumes and anterior cingulate gyrus metabolism, while performances for the recent period correlated with hippocampal volume and posterior cingulate, medial prefrontal and hippocampus metabolism. The brain regions related with the retrieval of events from the recent period showed greater atrophy/hypometabolism in aMCI patients compared to HC than those involved in remote memories. Recall of recent memories essentially relies on episodic memory processes and brain network while remote memories also involve other processes such as semantic memory. This is consistent with the semanticization of memories with time and may explain the better resistance of remote memory in AD. PMID:26106572

Brain structural, functional, and cognitive correlates of recent versus remote autobiographical memories in amnestic Mild Cognitive Impairment.

PubMed

Tomadesso, Clémence; Perrotin, Audrey; Mutlu, Justine; Mézenge, Florence; Landeau, Brigitte; Egret, Stéphanie; de la Sayette, Vincent; Jonin, Pierre-Yves; Eustache, Francis; Desgranges, Béatrice; Chételat, Gaël

2015-01-01

Deficits in autobiographical memory appear earlier for recent than for remote life periods over the course of Alzheimer's disease (AD). The present study aims to further our understanding of this graded effect by investigating the cognitive and neural substrates of recent versus remote autobiographical memories in patients with amnestic Mild Cognitive Impairment (aMCI) thanks to an autobiographical fluency task. 20 aMCI patients and 25 Healthy elderly Controls (HC) underwent neuropsychological tests assessing remote (20-to-30 years old) and recent (the ten last years) autobiographical memory as well as episodic and semantic memory, executive function and global cognition. All patients also had a structural MRI and an FDG-PET scan. Correlations were assessed between each autobiographical memory score and the other tests as well as grey matter volume and metabolism. Within the aMCI, performances for the remote period correlated with personal semantic memory and episodic memory retrieval whereas performances for the recent period only correlated with episodic memory retrieval. Neuroimaging analyses revealed significant correlations between performances for the remote period and temporal pole and temporo-parietal cortex volumes and anterior cingulate gyrus metabolism, while performances for the recent period correlated with hippocampal volume and posterior cingulate, medial prefrontal and hippocampus metabolism. The brain regions related with the retrieval of events from the recent period showed greater atrophy/hypometabolism in aMCI patients compared to HC than those involved in remote memories. Recall of recent memories essentially relies on episodic memory processes and brain network while remote memories also involve other processes such as semantic memory. This is consistent with the semanticization of memories with time and may explain the better resistance of remote memory in AD.

Bimanual coordination positively predicts episodic memory: A combined behavioral and MRI investigation.

PubMed

Lyle, Keith B; Dombroski, Brynn A; Faul, Leonard; Hopkins, Robin F; Naaz, Farah; Switala, Andrew E; Depue, Brendan E

2017-11-01

Some people remember events more completely and accurately than other people, but the origins of individual differences in episodic memory are poorly understood. One way to advance understanding is by identifying characteristics of individuals that reliably covary with memory performance. Recent research suggests motor behavior is related to memory performance, with individuals who consistently use a single preferred hand for unimanual actions performing worse than individuals who make greater use of both hands. This research has relied on self-reports of behavior. It is unknown whether objective measures of motor behavior also predict memory performance. Here, we tested the predictive power of bimanual coordination, an important form of manual dexterity. Bimanual coordination, as measured objectively on the Purdue Pegboard Test, was positively related to correct recall on the California Verbal Learning Test-II and negatively related to false recall. Furthermore, MRI data revealed that cortical surface area in right lateral prefrontal regions was positively related to correct recall. In one of these regions, cortical thickness was negatively related to bimanual coordination. These results suggest that individual differences in episodic memory may partially reflect morphological variation in right lateral prefrontal cortex and suggest a relationship between neural correlates of episodic memory and motor behavior. Copyright © 2017 Elsevier Inc. All rights reserved.

Considering the role of semantic memory in episodic future thinking: evidence from semantic dementia.

PubMed

Irish, Muireann; Addis, Donna Rose; Hodges, John R; Piguet, Olivier

2012-07-01

Semantic dementia is a progressive neurodegenerative condition characterized by the profound and amodal loss of semantic memory in the context of relatively preserved episodic memory. In contrast, patients with Alzheimer's disease typically display impairments in episodic memory, but with semantic deficits of a much lesser magnitude than in semantic dementia. Our understanding of episodic memory retrieval in these cohorts has greatly increased over the last decade, however, we know relatively little regarding the ability of these patients to imagine and describe possible future events, and whether episodic future thinking is mediated by divergent neural substrates contingent on dementia subtype. Here, we explored episodic future thinking in patients with semantic dementia (n=11) and Alzheimer's disease (n=11), in comparison with healthy control participants (n=10). Participants completed a battery of tests designed to probe episodic and semantic thinking across past and future conditions, as well as standardized tests of episodic and semantic memory. Further, all participants underwent magnetic resonance imaging. Despite their relatively intact episodic retrieval for recent past events, the semantic dementia cohort showed significant impairments for episodic future thinking. In contrast, the group with Alzheimer's disease showed parallel deficits across past and future episodic conditions. Voxel-based morphometry analyses confirmed that atrophy in the left inferior temporal gyrus and bilateral temporal poles, regions strongly implicated in semantic memory, correlated significantly with deficits in episodic future thinking in semantic dementia. Conversely, episodic future thinking performance in Alzheimer's disease correlated with atrophy in regions associated with episodic memory, namely the posterior cingulate, parahippocampal gyrus and frontal pole. These distinct neuroanatomical substrates contingent on dementia group were further qualified by correlational analyses that confirmed the relation between semantic memory deficits and episodic future thinking in semantic dementia, in contrast with the role of episodic memory deficits and episodic future thinking in Alzheimer's disease. Our findings demonstrate that semantic knowledge is critical for the construction of novel future events, providing the necessary scaffolding into which episodic details can be integrated. Further research is necessary to elucidate the precise contribution of semantic memory to future thinking, and to explore how deficits in self-projection manifest on behavioural and social levels in different dementia subtypes.

A Role for the Left Angular Gyrus in Episodic Simulation and Memory.

PubMed

Thakral, Preston P; Madore, Kevin P; Schacter, Daniel L

2017-08-23

Functional magnetic resonance imaging (fMRI) studies indicate that episodic simulation (i.e., imagining specific future experiences) and episodic memory (i.e., remembering specific past experiences) are associated with enhanced activity in a common set of neural regions referred to as the core network. This network comprises the hippocampus, medial prefrontal cortex, and left angular gyrus, among other regions. Because fMRI data are correlational, it is unknown whether activity increases in core network regions are critical for episodic simulation and episodic memory. In the current study, we used MRI-guided transcranial magnetic stimulation (TMS) to assess whether temporary disruption of the left angular gyrus would impair both episodic simulation and memory (16 participants, 10 females). Relative to TMS to a control site (vertex), disruption of the left angular gyrus significantly reduced the number of internal (i.e., episodic) details produced during the simulation and memory tasks, with a concomitant increase in external detail production (i.e., semantic, repetitive, or off-topic information), reflected by a significant detail by TMS site interaction. Difficulty in the simulation and memory tasks also increased after TMS to the left angular gyrus relative to the vertex. In contrast, performance in a nonepisodic control task did not differ statistically as a function of TMS site (i.e., number of free associates produced or difficulty in performing the free associate task). Together, these results are the first to demonstrate that the left angular gyrus is critical for both episodic simulation and episodic memory. SIGNIFICANCE STATEMENT Humans have the ability to imagine future episodes (i.e., episodic simulation) and remember episodes from the past (i.e., episodic memory). A wealth of neuroimaging studies have revealed that these abilities are associated with enhanced activity in a core network of neural regions, including the hippocampus, medial prefrontal cortex, and left angular gyrus. However, neuroimaging data are correlational and do not tell us whether core regions support critical processes for simulation and memory. In the current study, we used transcranial magnetic stimulation and demonstrated that temporary disruption of the left angular gyrus leads to impairments in simulation and memory. The present study provides the first causal evidence to indicate that this region is critical for these fundamental abilities. Copyright © 2017 the authors 0270-6474/17/378142-08$15.00/0.

A Role for the Left Angular Gyrus in Episodic Simulation and Memory

PubMed Central

2017-01-01

Functional magnetic resonance imaging (fMRI) studies indicate that episodic simulation (i.e., imagining specific future experiences) and episodic memory (i.e., remembering specific past experiences) are associated with enhanced activity in a common set of neural regions referred to as the core network. This network comprises the hippocampus, medial prefrontal cortex, and left angular gyrus, among other regions. Because fMRI data are correlational, it is unknown whether activity increases in core network regions are critical for episodic simulation and episodic memory. In the current study, we used MRI-guided transcranial magnetic stimulation (TMS) to assess whether temporary disruption of the left angular gyrus would impair both episodic simulation and memory (16 participants, 10 females). Relative to TMS to a control site (vertex), disruption of the left angular gyrus significantly reduced the number of internal (i.e., episodic) details produced during the simulation and memory tasks, with a concomitant increase in external detail production (i.e., semantic, repetitive, or off-topic information), reflected by a significant detail by TMS site interaction. Difficulty in the simulation and memory tasks also increased after TMS to the left angular gyrus relative to the vertex. In contrast, performance in a nonepisodic control task did not differ statistically as a function of TMS site (i.e., number of free associates produced or difficulty in performing the free associate task). Together, these results are the first to demonstrate that the left angular gyrus is critical for both episodic simulation and episodic memory. SIGNIFICANCE STATEMENT Humans have the ability to imagine future episodes (i.e., episodic simulation) and remember episodes from the past (i.e., episodic memory). A wealth of neuroimaging studies have revealed that these abilities are associated with enhanced activity in a core network of neural regions, including the hippocampus, medial prefrontal cortex, and left angular gyrus. However, neuroimaging data are correlational and do not tell us whether core regions support critical processes for simulation and memory. In the current study, we used transcranial magnetic stimulation and demonstrated that temporary disruption of the left angular gyrus leads to impairments in simulation and memory. The present study provides the first causal evidence to indicate that this region is critical for these fundamental abilities. PMID:28733357

Confabulation in healthy aging is related to interference of overlearned, semantically similar information on episodic memory recall.

PubMed

Dalla Barba, Gianfranco; Attali, Eve; La Corte, Valentina

2010-07-01

Normal aging is characterized by reduced performance on tasks of long-term memory. Older adults (OA) not only show reduced performance on tasks of recall and recognition memory, but also, compared to young adults (YA), are more vulnerable to memory distortions. In this study we describe the performance of a group of OA and a group of YA on the recall of three different types of story: a previously unknown story, a well-known fairy tale (Sleeping Beauty), and a modified well-known fairy tale (Little Red Riding Hood is not eaten by the wolf). The aim of our study was to test the hypothesis that in OA strongly represented, overlearned information interferes with episodic recall-that is, the retrieval of specific, unique past episodes. OA produced significantly more confabulations than YA and in particular in the recall of the modified fairy tale. Our findings indicate that the interference of strongly represented, overlearned information in episodic memory recall is implicated in the production of confabulations in OA. This effect is particularly prominent when the to-be remembered episodic information shows strong semantic similarities with preexisting, overlearned information.

Sleep benefits in parallel implicit and explicit measures of episodic memory.

PubMed

Weber, Frederik D; Wang, Jing-Yi; Born, Jan; Inostroza, Marion

2014-03-14

Research in rats using preferences during exploration as a measure of memory has indicated that sleep is important for the consolidation of episodic-like memory, i.e., memory for an event bound into specific spatio-temporal context. How these findings relate to human episodic memory is unclear. We used spontaneous preferences during visual exploration and verbal recall as, respectively, implicit and explicit measures of memory, to study effects of sleep on episodic memory consolidation in humans. During encoding before 10-h retention intervals that covered nighttime sleep or daytime wakefulness, two groups of young adults were presented with two episodes that were 1-h apart. Each episode entailed a spatial configuration of four different faces in a 3 × 3 grid of locations. After the retention interval, implicit spatio-temporal recall performance was assessed by eye-tracking visual exploration of another configuration of four faces of which two were from the first and second episode, respectively; of the two faces one was presented at the same location as during encoding and the other at another location. Afterward explicit verbal recall was assessed. Measures of implicit and explicit episodic memory retention were positively correlated (r = 0.57, P < 0.01), and were both better after nighttime sleep than daytime wakefulness (P < 0.05). In the sleep group, implicit episodic memory recall was associated with increased fast spindles during nonrapid eye movement (NonREM) sleep (r = 0.62, P < 0.05). Together with concordant observations in rats our results indicate that consolidation of genuinely episodic memory benefits from sleep.

Sleep benefits in parallel implicit and explicit measures of episodic memory

PubMed Central

Weber, Frederik D.; Wang, Jing-Yi; Born, Jan; Inostroza, Marion

2014-01-01

Research in rats using preferences during exploration as a measure of memory has indicated that sleep is important for the consolidation of episodic-like memory, i.e., memory for an event bound into specific spatio-temporal context. How these findings relate to human episodic memory is unclear. We used spontaneous preferences during visual exploration and verbal recall as, respectively, implicit and explicit measures of memory, to study effects of sleep on episodic memory consolidation in humans. During encoding before 10-h retention intervals that covered nighttime sleep or daytime wakefulness, two groups of young adults were presented with two episodes that were 1-h apart. Each episode entailed a spatial configuration of four different faces in a 3 × 3 grid of locations. After the retention interval, implicit spatio-temporal recall performance was assessed by eye-tracking visual exploration of another configuration of four faces of which two were from the first and second episode, respectively; of the two faces one was presented at the same location as during encoding and the other at another location. Afterward explicit verbal recall was assessed. Measures of implicit and explicit episodic memory retention were positively correlated (r = 0.57, P < 0.01), and were both better after nighttime sleep than daytime wakefulness (P < 0.05). In the sleep group, implicit episodic memory recall was associated with increased fast spindles during nonrapid eye movement (NonREM) sleep (r = 0.62, P < 0.05). Together with concordant observations in rats our results indicate that consolidation of genuinely episodic memory benefits from sleep. PMID:24634354

The facilitative effects of glucose ingestion on memory retrieval in younger and older adults: is task difficulty or task domain critical?

PubMed

Riby, Leigh M; McMurtrie, Hazel; Smallwood, Jonathan; Ballantyne, Carrie; Meikle, Andrew; Smith, Emily

2006-02-01

The ingestion of a glucose-containing drink has been shown to improve cognitive performance, particularly memory functioning. However, it remains unclear as to the extent to which task domain and task difficulty moderate the glucose enhancement effect. The aim of this research was to determine whether boosts in performance are restricted to particular classes of memory (episodic v. semantic) or to tasks of considerable cognitive load. A repeated measures (25 g glucose v. saccharin), counterbalanced, double-blind design was used with younger and older adults. Participants performed a battery of episodic (e.g. paired associate learning) and semantic memory (e.g. category verification) tasks under low and high cognitive load. Electrophysiological measures (heart rate and galvanic skin response) of arousal and mental effort were also gathered. The results indicated that whilst glucose appeared to aid episodic remembering, cognitive load did not exaggerate the facilitative effect. For semantic memory, there was little evidence to suggest that glucose can boost semantic memory retrieval even when the load was manipulated. One exception was that glucose facilitated performance during the difficult category fluency task. Regardless, the present findings are consistent with the domain-specific account in which glucose acts primarily on the hippocampal region, which is known to support episodic memory. The possible contribution of the hippocampus in semantic memory processing is also discussed.

The Asymmetrical Effects of Divided Attention on Encoding and Retrieval Processes: A Different View Based on an Interference with the Episodic Register

PubMed Central

Guez, Jonathan; Naveh-Benjamin, Moshe

2013-01-01

In this study, we evaluate the conceptualization of encoding and retrieval processes established in previous studies that used a divided attention (DA) paradigm. These studies indicated that there were considerable detrimental effects of DA at encoding on later memory performance, but only minimal effects, if any, on divided attention at retrieval. We suggest that this asymmetry in the effects of DA on memory can be due, at least partially, to a confound between the memory phase (encoding and retrieval) and the memory requirements of the task (memory “for” encoded information versus memory “at” test). To control for this confound, we tested memory for encoded information and for retrieved information by introducing a second test that assessed memory for the retrieved information from the first test. We report the results of four experiments that use measures of memory performance, retrieval latency, and performance on the concurrent task, all of which consistently show that DA at retrieval strongly disrupts later memory for the retrieved episode, similarly to the effects of DA at encoding. We suggest that these symmetrical disruptive effects of DA at encoding and retrieval on later retrieval reflect a disruption of an episodic buffer (EB) or episodic register component (ER), rather than a failure of encoding or retrieval operations per se. PMID:24040249

The asymmetrical effects of divided attention on encoding and retrieval processes: a different view based on an interference with the episodic register.

PubMed

Guez, Jonathan; Naveh-Benjamin, Moshe

2013-01-01

In this study, we evaluate the conceptualization of encoding and retrieval processes established in previous studies that used a divided attention (DA) paradigm. These studies indicated that there were considerable detrimental effects of DA at encoding on later memory performance, but only minimal effects, if any, on divided attention at retrieval. We suggest that this asymmetry in the effects of DA on memory can be due, at least partially, to a confound between the memory phase (encoding and retrieval) and the memory requirements of the task (memory "for" encoded information versus memory "at" test). To control for this confound, we tested memory for encoded information and for retrieved information by introducing a second test that assessed memory for the retrieved information from the first test. We report the results of four experiments that use measures of memory performance, retrieval latency, and performance on the concurrent task, all of which consistently show that DA at retrieval strongly disrupts later memory for the retrieved episode, similarly to the effects of DA at encoding. We suggest that these symmetrical disruptive effects of DA at encoding and retrieval on later retrieval reflect a disruption of an episodic buffer (EB) or episodic register component (ER), rather than a failure of encoding or retrieval operations per se.

Longitudinal Study of a Novel Performance-based Measure of Daily Function

DTIC Science & Technology

2015-04-01

measures of cognition (e.g., episodic memory , semantic memory , executive function, speed). We found that patients with MCI had compromises in...UPSA, as well as measures of cognition (e.g., episodic memory , semantic memory , executive function, speed). We found that patients with MCI had... memory , semantic memory , executive function, speed). We found that patients with MCI had compromises in everyday functional competence and that the

How Does Intentionality of Encoding Affect Memory for Episodic Information?

ERIC Educational Resources Information Center

Craig, Michael; Butterworth, Karla; Nilsson, Jonna; Hamilton, Colin J.; Gallagher, Peter; Smulders, Tom V.

2016-01-01

Episodic memory enables the detailed and vivid recall of past events, including target and wider contextual information. In this paper, we investigated whether/how encoding intentionality affects the retention of target and contextual episodic information from a novel experience. Healthy adults performed (1) a "What-Where-When"…

Pillars of judgment: how memory abilities affect performance in rule-based and exemplar-based judgments.

PubMed

Hoffmann, Janina A; von Helversen, Bettina; Rieskamp, Jörg

2014-12-01

Making accurate judgments is an essential skill in everyday life. Although how different memory abilities relate to categorization and judgment processes has been hotly debated, the question is far from resolved. We contribute to the solution by investigating how individual differences in memory abilities affect judgment performance in 2 tasks that induced rule-based or exemplar-based judgment strategies. In a study with 279 participants, we investigated how working memory and episodic memory affect judgment accuracy and strategy use. As predicted, participants switched strategies between tasks. Furthermore, structural equation modeling showed that the ability to solve rule-based tasks was predicted by working memory, whereas episodic memory predicted judgment accuracy in the exemplar-based task. Last, the probability of choosing an exemplar-based strategy was related to better episodic memory, but strategy selection was unrelated to working memory capacity. In sum, our results suggest that different memory abilities are essential for successfully adopting different judgment strategies. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Medial Temporal Lobe Damage Causes Deficits in Episodic Memory and Episodic Future Thinking Not Attributable to Deficits in Narrative Construction

PubMed Central

Race, Elizabeth; Keane, Margaret M.; Verfaellie, Mieke

2015-01-01

The medial temporal lobe (MTL) makes critical contributions to episodic memory, but its contributions to episodic future thinking remain a matter of debate. By one view, imagining future events relies on MTL mechanisms that also support memory for past events. Alternatively, it has recently been suggested that future thinking is independent of MTL-mediated processes and can be supported by regions outside the MTL. The current study investigated the nature and necessity of MTL involvement in imagining the future and tested the novel hypothesis that the MTL contributes to future thinking by supporting online binding processes related to narrative construction. Human amnesic patients with well-characterized MTL damage and healthy controls constructed narratives about (a) future events, (b) past events, and (c) visually-presented pictures. While all three tasks place similar demands on narrative construction, only the past and future conditions require memory/future thinking to mentally generate relevant narrative information. Patients produced impoverished descriptions of both past and future events but were unimpaired at producing detailed picture narratives. In addition, future-thinking performance positively correlated with episodic memory performance but did not correlate with picture narrative performance. Finally, future-thinking impairments were present when MTL lesions were restricted to the hippocampus and did not depend on the presence of neural damage outside the MTL. These results indicate that the ability to generate and maintain a detailed narrative is preserved in amnesia and suggest that a common MTL mechanism supports both episodic memory and episodic future thinking. PMID:21753003

Medial temporal lobe damage causes deficits in episodic memory and episodic future thinking not attributable to deficits in narrative construction.

PubMed

Race, Elizabeth; Keane, Margaret M; Verfaellie, Mieke

2011-07-13

The medial temporal lobe (MTL) makes critical contributions to episodic memory, but its contributions to episodic future thinking remain a matter of debate. By one view, imagining future events relies on MTL mechanisms that also support memory for past events. Alternatively, it has recently been suggested that future thinking is independent of MTL-mediated processes and can be supported by regions outside the MTL. The current study investigated the nature and necessity of MTL involvement in imagining the future and tested the novel hypothesis that the MTL contributes to future thinking by supporting online binding processes related to narrative construction. Human amnesic patients with well characterized MTL damage and healthy controls constructed narratives about (1) future events, (2) past events, and (3) visually presented pictures. While all three tasks place similar demands on narrative construction, only the past and future conditions require memory/future thinking to mentally generate relevant narrative information. Patients produced impoverished descriptions of both past and future events but were unimpaired at producing detailed picture narratives. In addition, future-thinking performance positively correlated with episodic memory performance but did not correlate with picture narrative performance. Finally, future-thinking impairments were present when MTL lesions were restricted to the hippocampus and did not depend on the presence of neural damage outside the MTL. These results indicate that the ability to generate and maintain a detailed narrative is preserved in amnesia and suggest that a common MTL mechanism supports both episodic memory and episodic future thinking.

Diet-Induced Weight Loss Alters Functional Brain Responses during an Episodic Memory Task.

PubMed

Boraxbekk, Carl-Johan; Stomby, Andreas; Ryberg, Mats; Lindahl, Bernt; Larsson, Christel; Nyberg, Lars; Olsson, Tommy

2015-01-01

It has been suggested that overweight is negatively associated with cognitive functions. The aim of this study was to investigate whether a reduction in body weight by dietary interventions could improve episodic memory performance and alter associated functional brain responses in overweight and obese women. 20 overweight postmenopausal women were randomized to either a modified paleolithic diet or a standard diet adhering to the Nordic Nutrition Recommendations for 6 months. We used functional magnetic resonance imaging to examine brain function during an episodic memory task as well as anthropometric and biochemical data before and after the interventions. Episodic memory performance improved significantly (p = 0.010) after the dietary interventions. Concomitantly, brain activity increased in the anterior part of the right hippocampus during memory encoding, without differences between diets. This was associated with decreased levels of plasma free fatty acids (FFA). Brain activity increased in pre-frontal cortex and superior/middle temporal gyri. The magnitude of increase correlated with waist circumference reduction. During episodic retrieval, brain activity decreased in inferior and middle frontal gyri, and increased in middle/superior temporal gyri. Diet-induced weight loss, associated with decreased levels of plasma FFA, improves episodic memory linked to increased hippocampal activity. © 2015 S. Karger GmbH, Freiburg.

Diet-Induced Weight Loss Alters Functional Brain Responses during an Episodic Memory Task

PubMed Central

Boraxbekk, Carl-Johan; Stomby, Andreas; Ryberg, Mats; Lindahl, Bernt; Larsson, Christel; Nyberg, Lars; Olsson, Tommy

2015-01-01

Objective It has been suggested that overweight is negatively associated with cognitive functions. The aim of this study was to investigate whether a reduction in body weight by dietary interventions could improve episodic memory performance and alter associated functional brain responses in overweight and obese women. Methods 20 overweight postmenopausal women were randomized to either a modified paleolithic diet or a standard diet adhering to the Nordic Nutrition Recommendations for 6 months. We used functional magnetic resonance imaging to examine brain function during an episodic memory task as well as anthropometric and biochemical data before and after the interventions. Results Episodic memory performance improved significantly (p = 0.010) after the dietary interventions. Concomitantly, brain activity increased in the anterior part of the right hippocampus during memory encoding, without differences between diets. This was associated with decreased levels of plasma free fatty acids (FFA). Brain activity increased in pre-frontal cortex and superior/middle temporal gyri. The magnitude of increase correlated with waist circumference reduction. During episodic retrieval, brain activity decreased in inferior and middle frontal gyri, and increased in middle/superior temporal gyri. Conclusions Diet-induced weight loss, associated with decreased levels of plasma FFA, improves episodic memory linked to increased hippocampal activity. PMID:26139105

Hey Teacher, Don't Leave Them Kids Alone: Action Is Better for Memory than Reading.

PubMed

Hainselin, Mathieu; Picard, Laurence; Manolli, Patrick; Vankerkore-Candas, Sophie; Bourdin, Béatrice

2017-01-01

There is no consensus on how the enactment effect (EE), although it is robust, enhances memory. Researchers are currently investigating the cognitive processes underlying this effect, mostly during adulthood; the link between EE and crucial function identified in adulthood such as episodic memory and binding process remains elusive. Therefore, this study aims to verify the existence of EE in 6-10 years old and assess cognitive functions potentially linked to this effect in order to shed light on the mechanisms underlying the EE during childhood. Thirty-five children (15 second graders and 20 fifth graders) were included in this study. They encoded 24 action phrases from a protocol adapted from Hainselin et al. (2014). Encoding occurred under four conditions: Verbal Task, Listening Task, Experimenter-Performed Task, and Subject-Performed Task. Memory performance was assessed for free and cued recall, as well as source memory abilities. ANOVAS were conducted to explore age-related effects on the different scores according to encoding conditions. Correlations between EE scores (Subject-Performed Task/Listening Task) and binding memory scores (short-term binding and episodic memory) were run. Both groups benefited from EE. However, in both groups, performance did not significantly differ between Subject-Performed Task and Experimenter-Performed Task. A positive correlation was found between EE and episodic memory score for second graders and a moderate negative correlation was found between EE and binding scores for fifth graders. Our results confirm the existence of EE in 6 and 10 year olds, but they do not support the multimodal theory (Engelkamp, 2001) or the "glue" theory (Kormi-Nouri and Nilsson, 2001). This suggests instead that episodic memory might not underlie EE during early childhood.

Everyday episodic memory in amnestic mild cognitive impairment: a preliminary investigation.

PubMed

Irish, Muireann; Lawlor, Brian A; Coen, Robert F; O'Mara, Shane M

2011-08-04

Decline in episodic memory is one of the hallmark features of Alzheimer's disease (AD) and is also a defining feature of amnestic Mild Cognitive Impairment (MCI), which is posited as a potential prodrome of AD. While deficits in episodic memory are well documented in MCI, the nature of this impairment remains relatively under-researched, particularly for those domains with direct relevance and meaning for the patient's daily life. In order to fully explore the impact of disruption to the episodic memory system on everyday memory in MCI, we examined participants' episodic memory capacity using a battery of experimental tasks with real-world relevance. We investigated episodic acquisition and delayed recall (story-memory), associative memory (face-name pairings), spatial memory (route learning and recall), and memory for everyday mundane events in 16 amnestic MCI and 18 control participants. Furthermore, we followed MCI participants longitudinally to gain preliminary evidence regarding the possible predictive efficacy of these real-world episodic memory tasks for subsequent conversion to AD. The most discriminating tests at baseline were measures of acquisition, delayed recall, and associative memory, followed by everyday memory, and spatial memory tasks, with MCI patients scoring significantly lower than controls. At follow-up (mean time elapsed: 22.4 months), 6 MCI cases had progressed to clinically probable AD. Exploratory logistic regression analyses revealed that delayed associative memory performance at baseline was a potential predictor of subsequent conversion to AD. As a preliminary study, our findings suggest that simple associative memory paradigms with real-world relevance represent an important line of enquiry in future longitudinal studies charting MCI progression over time.

Mechanisms underlying the production of false memories for famous people's names in aging and Alzheimer's disease.

PubMed

Plancher, Gaën; Guyard, Anne; Nicolas, Serge; Piolino, Pascale

2009-10-01

It is well known that the occurrence of false memories increases with aging, but the results remain inconsistent concerning Alzheimer's disease (AD). Moreover, the mechanisms underlying the production of false memories are still unclear. Using an experimental episodic memory test with material based on the names of famous people in a procedure derived from the DRM paradigm [Roediger, H. L., III, & McDermott, K. B. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory & Cognition, 21, 803-814], we examined correct and false recall and recognition in 30 young adults, 40 healthy older adults, and 30 patients with AD. Moreover, we evaluated the relationships between false memory performance, correct episodic memory performance, and a set of neuropsychological assessments evaluating the semantic memory and executive functions. The results clearly indicated that correct recall and recognition performance decreased with the subjects' age, but it decreased even more with AD. In addition, semantically related false recalls and false recognitions increased with age but not with dementia. On the contrary, non-semantically related false recalls and false recognitions increased with AD. Finally, the regression analyses showed that executive functions mediated related false memories and episodic memory mediated related and unrelated false memories in aging. Moreover, executive functions predicted related and unrelated false memories in AD, and episodic and semantic memory predicted semantically related and unrelated false memories in AD. In conclusion, the results obtained are consistent with the current constructive models of memory suggesting that false memory creation depends on different cognitive functions and, consequently, that the impairments of these functions influence the production of false memories.

Common and unique gray matter correlates of episodic memory dysfunction in frontotemporal dementia and Alzheimer's disease.

PubMed

Irish, Muireann; Piguet, Olivier; Hodges, John R; Hornberger, Michael

2014-04-01

Conflicting evidence exists regarding the integrity of episodic memory in the behavioral variant of frontotemporal dementia (bvFTD). Recent converging evidence suggests that episodic memory in progressive cases of bvFTD is compromised to the same extent as in Alzheimer's disease (AD). The underlying neural substrates of these episodic memory deficits, however, likely differ contingent on dementia type. In this study we sought to elucidate the neural substrates of episodic memory performance, across recall and recognition tasks, in both patient groups using voxel-based morphometry (VBM) analyses. We predicted that episodic memory dysfunction would be apparent in both patient groups but would relate to divergent patterns of neural atrophy specific to each dementia type. We assessed episodic memory, across verbal and visual domains, in 19 bvFTD, 18 AD patients, and 19 age- and education-matched controls. Behaviorally, patient groups were indistinguishable for immediate and delayed recall, across verbal and visual domains. Whole-brain VBM analyses revealed regions commonly implicated in episodic retrieval across groups, namely the right temporal pole, right frontal lobe, left paracingulate gyrus, and right anterior hippocampus. Divergent neural networks specific to each group were also identified. Whereas a widespread network including posterior regions such as the posterior cingulate cortex, parietal and occipital cortices was exclusively implicated in AD, the frontal and anterior temporal lobes underpinned the episodic memory deficits in bvFTD. Our results point to distinct neural changes underlying episodic memory decline specific to each dementia syndrome. Copyright © 2013 Wiley Periodicals, Inc.

Frontotemporal Functional Connectivity and Executive Functions Contribute to Episodic Memory Performance

PubMed Central

Blankenship, Tashauna L.; O'Neill, Meagan; Deater-Deckard, Kirby; Diana, Rachel A.; Bell, Martha Ann

2016-01-01

The contributions of hemispheric-specific electrophysiology (electroencephalogram or EEG) and independent executive functions (inhibitory control, working memory, cognitive flexibility) to episodic memory performance were examined using abstract paintings. Right hemisphere frontotemporal functional connectivity during encoding and retrieval, measured via EEG alpha coherence, statistically predicted performance on recency but not recognition judgments for the abstract paintings. Theta coherence, however, did not predict performance. Likewise, cognitive flexibility statistically predicted performance on recency judgments, but not recognition. These findings suggest that recognition and recency operate via separate electrophysiological and executive mechanisms. PMID:27388478

Such stuff as dreams are made on? Elaborative encoding, the ancient art of memory, and the hippocampus.

PubMed

Llewellyn, Sue

2013-12-01

This article argues that rapid eye movement (REM) dreaming is elaborative encoding for episodic memories. Elaborative encoding in REM can, at least partially, be understood through ancient art of memory (AAOM) principles: visualization, bizarre association, organization, narration, embodiment, and location. These principles render recent memories more distinctive through novel and meaningful association with emotionally salient, remote memories. The AAOM optimizes memory performance, suggesting that its principles may predict aspects of how episodic memory is configured in the brain. Integration and segregation are fundamental organizing principles in the cerebral cortex. Episodic memory networks interconnect profusely within the cortex, creating omnidirectional "landmark" junctions. Memories may be integrated at junctions but segregated along connecting network paths that meet at junctions. Episodic junctions may be instantiated during non-rapid eye movement (NREM) sleep after hippocampal associational function during REM dreams. Hippocampal association involves relating, binding, and integrating episodic memories into a mnemonic compositional whole. This often bizarre, composite image has not been present to the senses; it is not "real" because it hyperassociates several memories. During REM sleep, on the phenomenological level, this composite image is experienced as a dream scene. A dream scene may be instantiated as omnidirectional neocortical junction and retained by the hippocampus as an index. On episodic memory retrieval, an external stimulus (or an internal representation) is matched by the hippocampus against its indices. One or more indices then reference the relevant neocortical junctions from which episodic memories can be retrieved. Episodic junctions reach a processing (rather than conscious) level during normal wake to enable retrieval. If this hypothesis is correct, the stuff of dreams is the stuff of memory.

Transfer after process-based object-location memory training in healthy older adults.

PubMed

Zimmermann, Kathrin; von Bastian, Claudia C; Röcke, Christina; Martin, Mike; Eschen, Anne

2016-11-01

A substantial part of age-related episodic memory decline has been attributed to the decreasing ability of older adults to encode and retrieve associations among simultaneously processed information units from long-term memory. In addition, this ability seems to share unique variance with reasoning. In this study, we therefore examined whether process-based training of the ability to learn and remember associations has the potential to induce transfer effects to untrained episodic memory and reasoning tasks in healthy older adults (60-75 years). For this purpose, the experimental group (n = 36) completed 30 sessions of process-based object-location memory training, while the active control group (n = 31) practiced visual perception on the same material. Near (spatial episodic memory), intermediate (verbal episodic memory), and far transfer effects (reasoning) were each assessed with multiple tasks at four measurements (before, midway through, immediately after, and 4 months after training). Linear mixed-effects models revealed transfer effects on spatial episodic memory and reasoning that were still observed 4 months after training. These results provide first empirical evidence that process-based training can enhance healthy older adults' associative memory performance and positively affect untrained episodic memory and reasoning abilities. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Dynamic memory searches: Selective output interference for the memory of facts.

PubMed

Aue, William R; Criss, Amy H; Prince, Melissa A

2015-12-01

The benefits of testing on later memory performance are well documented; however, the manner in which testing harms memory performance is less well understood. This research is concerned with the finding that accuracy decreases over the course of testing, a phenomena termed "output interference" (OI). OI has primarily been investigated with episodic memory, but there is limited research investigating OI in measures of semantic memory (i.e., knowledge). In the current study, participants were twice tested for their knowledge of factual questions; they received corrective feedback during the first test. No OI was observed during the first test, when participants presumably searched semantic memory to answer the general-knowledge questions. During the second test, OI was observed. Conditional analyses of Test 2 performance revealed that OI was largely isolated to questions answered incorrectly during Test 1. These were questions for which participants needed to rely on recent experience (i.e., the feedback in episodic memory) to respond correctly. One possible explanation is that episodic memory is more susceptible to the sort of interference generated during testing (e.g., gradual changes in context, encoding/updating of items) relative to semantic memory. Alternative explanations are considered.

Intake of Wild Blueberry Powder Improves Episodic-Like and Working Memory during Normal Aging in Mice.

PubMed

Beracochea, Daniel; Krazem, Ali; Henkouss, Nadia; Haccard, Guillaume; Roller, Marc; Fromentin, Emilie

2016-08-01

The number of Americans older than 65 years old is projected to more than double in the next 40 years. Cognitive changes associated to aging can affect an adult's day-to-day functioning. Among these cognitive changes, reasoning, episodic memory, working memory, and processing speed decline gradually over time. Early memory changes include a decline in both working and episodic memory. The aim of the present study was to determine whether chronic (up to 75 days) daily administration of wild blueberry extract or a wild blueberry full spectrum powder would help prevent memory failure associated with aging in tasks involving various forms of memory. Both blueberry ingredients were used in a study comparing young mice (6 months old) to aged mice (18 months old). At this age, mice exhibit memory decline due to aging, which is exacerbated first by a loss in working and contextual (episodic-like) memory. Contextual memory (episodic-like memory) was evaluated using the contextual serial discrimination test. Working and spatial memory were evaluated using the Morris-Water maze test and the sequential alternation test. Statistical analysis was performed using an ANOVA with the Bonferroni post-hoc test. Supplementation with wild blueberry full spectrum powder and wild blueberry extract resulted in significant improvement of contextual memory, while untreated aged mice experienced a decline in such memory. Only the wild blueberry full spectrum powder significantly contributed to an improvement of spatial and working memory versus untreated aged mice. These improvements of cognitive performance may be related to brain oxidative status, acetylcholinesterase activity, neuroprotection, or attenuation of immunoreactivity. Georg Thieme Verlag KG Stuttgart · New York.

Homotaurine Effects on Hippocampal Volume Loss and Episodic Memory in Amnestic Mild Cognitive Impairment.

PubMed

Spalletta, Gianfranco; Cravello, Luca; Gianni, Walter; Piras, Federica; Iorio, Mariangela; Cacciari, Claudia; Casini, Anna Rosa; Chiapponi, Chiara; Sancesario, Giuseppe; Fratangeli, Claudia; Orfei, Maria Donata; Caltagirone, Carlo; Piras, Fabrizio

2016-01-01

Homotaurine supplementation may have a positive effect on early Alzheimer's disease. Here, we investigated its potential neuroprotective effect on the hippocampus structure and episodic memory performances in amnestic mild cognitive impairment (aMCI). Neuropsychological, clinical, and neuroimaging assessment in 11 treated and 22 untreated patients were performed at baseline and after 1 year. Magnetic resonance data were analyzed using voxel-based morphometry to explore significant differences (Family Wise Error corrected) between the two groups over time. Patients treated with homotaurine showed decreased volume loss in the left and right hippocampal tail, left and right fusiform gyrus, and right inferior temporal cortex which was associated with improved short-term episodic memory performance as measured by the recency effect of the Rey 15-word list learning test immediate recall. Thus, homotaurine supplementation in individuals with aMCI has a positive effect on hippocampus atrophy and episodic memory loss. Future studies should further clarify the mechanisms of its effects on brain morphometry.

Sleep-dependent consolidation patterns reveal insights into episodic memory structure.

PubMed

Oyanedel, Carlos N; Sawangjit, Anuck; Born, Jan; Inostroza, Marion

2018-05-18

Episodic memory formation is considered a genuinely hippocampal function. Its study in rodents has relied on two different task paradigms, i.e. the so called "what-where-when" (WW-When) task and "what-where-which" (WW-Which) task. The WW-When task aims to assess the memory for an episode as an event bound into its context defined by spatial and distinct temporal information, the WW-Which task lacks the temporal component and introduces, instead, an "occasion setter" marking the broader contextual configuration in which the event occurred. Whether both tasks measure episodic memory in an equivalent manner in terms of recollection has been controversially discussed. Here, we compared in two groups of rats the consolidating effects of sleep on episodic-like memory between both task paradigms. Sampling and test phases were separated by a 90-min morning retention interval which did or did not allow for spontaneous sleep. Results show that sleep is crucial for the consolidation of the memory on both tasks. However, consolidating effects of sleep were stronger for the WW-Which than WW-When task. Comparing performance during the post-sleep test phase revealed that WW-When memory only gradually emerged during the 3-min test period whereas WW-Which memory was readily expressed already from the first minute onward. Separate analysis of the temporal and spatial components of WW-When performance showed that the delayed episodic memory on this task originated from the temporal component which also did not emerge until the third minute of the test phase, whereas the spatial component already showed up in the first minute. In conclusion, sleep differentially affects consolidation on the two episodic-like memory tasks, with the delayed expression of WW-When memory after sleep resulting from preferential coverage of temporal aspects by this task. Copyright © 2018. Published by Elsevier Inc.

Episodic memory change in late adulthood: generalizability across samples and performance indices.

PubMed

Dixon, Roger A; Wahlin, Ake; Maitland, Scott B; Hultsch, David F; Hertzog, Christopher; Bäckman, Lars

2004-07-01

Younger adults recall more information from episodic memory tasks than do older adults. Because longitudinal studies are rare and often incompatible, the extent of actual late-life memory change is not well established. We assemble two different longitudinal samples of normal older adults, each of which is tested twice at a 3-year interval, using a large battery of episodic memory indicators. Together, two-wave data from both the Victoria Longitudinal Study in Canada (n = 400) and the Kungsholmen Project in Sweden (n = 168) cover a 40-year span of adulthood, ranging from 54 to 94 years of age. Principal memory tasks include categorizable word lists, story recall, and random word lists, as well as indicators of cognitive support. Overall, an examination of performance on sets of common and complementary episodic tasks reveals that, for both samples, actual 3-year changes are modest and that, when decline occurs, it is gradual. The exception-greater decline for more supported tasks-suggests that these may be especially sensitive to late-life changes.

Associations between cognitively stimulating leisure activities, cognitive function and age-related cognitive decline.

PubMed

Ferreira, Nicola; Owen, Adrian; Mohan, Anita; Corbett, Anne; Ballard, Clive

2015-04-01

Emerging literature suggests that lifestyle factors may play an important role in reducing age-related cognitive decline. There have, however, been few studies investigating the role of cognitively stimulating leisure activities in maintaining cognitive health. This study sought to identify changes in cognitive performance with age and to investigate associations of cognitive performance with several key cognitively stimulating leisure activities. Over 65,000 participants provided demographic and lifestyle information and completed tests of grammatical reasoning, spatial working memory, verbal working memory and episodic memory. Regression analyses suggested that frequency of engaging in Sudoku or similar puzzles was significantly positively associated with grammatical reasoning, spatial working memory and episodic memory scores. Furthermore, for participants aged under 65 years, frequency of playing non-cognitive training computer games was also positively associated with performance in the same cognitive domains. The results also suggest that grammatical reasoning and episodic memory are particularly vulnerable to age-related decline. Further investigation to determine the potential benefits of participating in Sudoku puzzles and non-cognitive computer games is indicated, particularly as they are associated with grammatical reasoning and episodic memory, cognitive domains found to be strongly associated with age-related cognitive decline. Results of this study have implications for developing improved guidance for the public regarding the potential value of cognitively stimulating leisure activities. The results also suggest that grammatical reasoning and episodic memory should be targeted in developing appropriate outcome measures to assess efficacy of future interventions, and in developing cognitive training programmes to prevent or delay cognitive decline. Copyright © 2014 John Wiley & Sons, Ltd.

Self-projection in younger and older adults: a study of episodic memory, prospection, and theory of mind.

PubMed

Jarvis, Shoshana N; Miller, Jeremy K

2017-07-01

Self-projection is the ability to orient the self in different places in time and space. Episodic memory, prospection, and theory of mind (ToM) are all cognitive abilities that share an element of self-projection. Previous research has posited that each of these abilities stems from the same neural network. The current study compared performance of cognitively healthy older adults and younger adults on several self-projection tasks to examine the relatedness of these constructs behaviorally. Episodic memory and prospection were measured using an episodic interview task where the participants were asked to remember or imagine events that either had happened in the past or could happen in the future and then gave ratings describing the extent to which they were mentally experiencing the event and from what perspective they viewed it. ToM was measured by asking participants to make judgments regarding the intentions of characters described in stories that involved cognitive, affective, or ironic components. Our results demonstrate that aging influences episodic memory, prospection, and ToM similarly: older adult participants showed declines on each of these measures compared to younger adults. Further, we observed correlations between performance on the measures of episodic memory and prospection as well as between episodic memory and ToM, although no correlation between prospection and ToM was observed after controlling for chronological age. We discuss these results in the light of theories suggesting that each of these abilities is governed by a common brain system.

Everyday episodic memory in amnestic mild cognitive impairment: a preliminary investigation

PubMed Central

2011-01-01

Background Decline in episodic memory is one of the hallmark features of Alzheimer's disease (AD) and is also a defining feature of amnestic Mild Cognitive Impairment (MCI), which is posited as a potential prodrome of AD. While deficits in episodic memory are well documented in MCI, the nature of this impairment remains relatively under-researched, particularly for those domains with direct relevance and meaning for the patient's daily life. In order to fully explore the impact of disruption to the episodic memory system on everyday memory in MCI, we examined participants' episodic memory capacity using a battery of experimental tasks with real-world relevance. We investigated episodic acquisition and delayed recall (story-memory), associative memory (face-name pairings), spatial memory (route learning and recall), and memory for everyday mundane events in 16 amnestic MCI and 18 control participants. Furthermore, we followed MCI participants longitudinally to gain preliminary evidence regarding the possible predictive efficacy of these real-world episodic memory tasks for subsequent conversion to AD. Results The most discriminating tests at baseline were measures of acquisition, delayed recall, and associative memory, followed by everyday memory, and spatial memory tasks, with MCI patients scoring significantly lower than controls. At follow-up (mean time elapsed: 22.4 months), 6 MCI cases had progressed to clinically probable AD. Exploratory logistic regression analyses revealed that delayed associative memory performance at baseline was a potential predictor of subsequent conversion to AD. Conclusions As a preliminary study, our findings suggest that simple associative memory paradigms with real-world relevance represent an important line of enquiry in future longitudinal studies charting MCI progression over time. PMID:21816065

The influence of aging on attentional refreshing and articulatory rehearsal during working memory on later episodic memory performance.

PubMed

Loaiza, Vanessa M; McCabe, David P

2013-01-01

We investigated age-related changes in two proposed mechanisms of maintenance in working memory, articulatory rehearsal, and attentional refreshing, by examining the consequences of manipulating the opportunity for each on delayed recall. Both experiments utilized modified operation span tasks to vary the opportunity for articulatory rehearsal (Experiment 1) and attentional refreshing opportunities (Experiment 2). In both experiments, episodic memory was tested for items that had been initially studied during the respective operation span task. Older adults' episodic memory benefited less from opportunities for refreshing than younger adults. In contrast, articulatory rehearsal opportunities did not influence episodic memory for either age group. The results suggest that attentional refreshing, and not articulatory rehearsal, is important during working memory in order to bind more accessible traces at later tests, which appears to be more deficient in older adults than younger adults.

Single-trial Phase Entrainment of Theta Oscillations in Sensory Regions Predicts Human Associative Memory Performance.

PubMed

Wang, Danying; Clouter, Andrew; Chen, Qiaoyu; Shapiro, Kimron L; Hanslmayr, Simon

2018-06-13

Episodic memories are rich in sensory information and often contain integrated information from different sensory modalities. For instance, we can store memories of a recent concert with visual and auditory impressions being integrated in one episode. Theta oscillations have recently been implicated in playing a causal role synchronizing and effectively binding the different modalities together in memory. However, an open question is whether momentary fluctuations in theta synchronization predict the likelihood of associative memory formation for multisensory events. To address this question we entrained the visual and auditory cortex at theta frequency (4 Hz) and in a synchronous or asynchronous manner by modulating the luminance and volume of movies and sounds at 4 Hz, with a phase offset at 0° or 180°. EEG activity from human subjects (both sexes) was recorded while they memorized the association between a movie and a sound. Associative memory performance was significantly enhanced in the 0° compared to the 180° condition. Source-level analysis demonstrated that the physical stimuli effectively entrained their respective cortical areas with a corresponding phase offset. The findings suggested a successful replication of a previous study (Clouter et al., 2017). Importantly, the strength of entrainment during encoding correlated with the efficacy of associative memory such that small phase differences between visual and auditory cortex predicted a high likelihood of correct retrieval in a later recall test. These findings suggest that theta oscillations serve a specific function in the episodic memory system: Binding the contents of different modalities into coherent memory episodes. SIGNIFICANCE STATEMENT How multi-sensory experiences are bound to form a coherent episodic memory representation is one of the fundamental questions in human episodic memory research. Evidence from animal literature suggests that the relative timing between an input and theta oscillations in the hippocampus is crucial for memory formation. We precisely controlled the timing between visual and auditory stimuli and the neural oscillations at 4 Hz using a multisensory entrainment paradigm. Human associative memory formation depends on coincident timing between sensory streams processed by the corresponding brain regions. We provide evidence for a significant role of relative timing of neural theta activity in human episodic memory on a single trial level, which reveals a crucial mechanism underlying human episodic memory. Copyright © 2018 the authors.

No Evidence for Improved Associative Memory Performance Following Process-Based Associative Memory Training in Older Adults

PubMed Central

Bellander, Martin; Eschen, Anne; Lövdén, Martin; Martin, Mike; Bäckman, Lars; Brehmer, Yvonne

2017-01-01

Studies attempting to improve episodic memory performance with strategy instructions and training have had limited success in older adults: their training gains are limited in comparison to those of younger adults and do not generalize to untrained tasks and contexts. This limited success has been partly attributed to age-related impairments in associative binding of information into coherent episodes. We therefore investigated potential training and transfer effects of process-based associative memory training (i.e., repeated practice). Thirty-nine older adults (Mage = 68.8) underwent 6 weeks of either adaptive associative memory training or item recognition training. Both groups improved performance in item memory, spatial memory (object-context binding) and reasoning. A disproportionate effect of associative memory training was only observed for item memory, whereas no training-related performance changes were observed for associative memory. Self-reported strategies showed no signs of spontaneous development of memory-enhancing associative memory strategies. Hence, the results do not support the hypothesis that process-based associative memory training leads to higher associative memory performance in older adults. PMID:28119597

No Evidence for Improved Associative Memory Performance Following Process-Based Associative Memory Training in Older Adults.

PubMed

Bellander, Martin; Eschen, Anne; Lövdén, Martin; Martin, Mike; Bäckman, Lars; Brehmer, Yvonne

2016-01-01

Studies attempting to improve episodic memory performance with strategy instructions and training have had limited success in older adults: their training gains are limited in comparison to those of younger adults and do not generalize to untrained tasks and contexts. This limited success has been partly attributed to age-related impairments in associative binding of information into coherent episodes. We therefore investigated potential training and transfer effects of process-based associative memory training (i.e., repeated practice). Thirty-nine older adults ( M age = 68.8) underwent 6 weeks of either adaptive associative memory training or item recognition training. Both groups improved performance in item memory, spatial memory (object-context binding) and reasoning. A disproportionate effect of associative memory training was only observed for item memory, whereas no training-related performance changes were observed for associative memory. Self-reported strategies showed no signs of spontaneous development of memory-enhancing associative memory strategies. Hence, the results do not support the hypothesis that process-based associative memory training leads to higher associative memory performance in older adults.

Episodic foresight deficits in regular, but not recreational, cannabis users.

PubMed

Mercuri, Kimberly; Terrett, Gill; Henry, Julie D; Curran, H Valerie; Elliott, Morgan; Rendell, Peter G

2018-06-01

Cannabis use is associated with a range of neurocognitive deficits, including impaired episodic memory. However, no study to date has assessed whether these difficulties extend to episodic foresight, a core component of which is the ability to mentally travel into one's personal future. This is a particularly surprising omission given that episodic memory is considered to be critical to engage episodic foresight. In the present study, we provide the first test of how episodic foresight is affected in the context of differing levels of cannabis use, and the degree to which performance on a measure of this construct is related to episodic memory. Fifty-seven regular cannabis users (23 recreational, 34 regular) and 57 controls were assessed using an adapted version of the Autobiographical Interview. The results showed that regular-users exhibited greater impairment of episodic foresight and episodic memory than both recreational-users and cannabis-naïve controls. These data therefore show for the first time that cannabis-related disruption of cognitive functioning extends to the capacity for episodic foresight, and they are discussed in relation to their potential implications for functional outcomes in this group.

Altered cognitive development in the siblings of individuals with schizophrenia

PubMed Central

Barch, Deanna M.; Cohen, Rachel; Csernansky, John

2014-01-01

The goal of the current study was to further investigate the late neurodevelopmental hypothesis of schizophrenia by examining cross-sectional, age-related changes in cognitive function among young adult: 1) siblings of individuals with schizophrenia (N = 66); (2) healthy control participants (N = 77); and (3) the siblings of healthy controls (N = 77). All subjects participated in a battery of tasks in four domains: 1) IQ; 2) working memory; 3) episodic memory; and 4) executive function. We found significant group differences in the relationships between age and performance in working memory and episodic memory, with similar patterns for executive function and verbal IQ. The siblings of individuals with schizophrenia showed impaired performance in working memory, episodic memory, and executive function. In addition, healthy controls and/or their siblings showed age-related improvements in all four cognitive domains, while the siblings of individuals with schizophrenia only showed this for verbal IQ. PMID:25485180

Altered cognitive development in the siblings of individuals with schizophrenia.

PubMed

Barch, Deanna M; Cohen, Rachel; Csernansky, John

2014-03-01

The goal of the current study was to further investigate the late neurodevelopmental hypothesis of schizophrenia by examining cross-sectional, age-related changes in cognitive function among young adult: 1) siblings of individuals with schizophrenia (N = 66); (2) healthy control participants (N = 77); and (3) the siblings of healthy controls (N = 77). All subjects participated in a battery of tasks in four domains: 1) IQ; 2) working memory; 3) episodic memory; and 4) executive function. We found significant group differences in the relationships between age and performance in working memory and episodic memory, with similar patterns for executive function and verbal IQ. The siblings of individuals with schizophrenia showed impaired performance in working memory, episodic memory, and executive function. In addition, healthy controls and/or their siblings showed age-related improvements in all four cognitive domains, while the siblings of individuals with schizophrenia only showed this for verbal IQ.

From episodic to habitual prospective memory: ERP-evidence for a linear transition

PubMed Central

Meier, Beat; Matter, Sibylle; Baumann, Brigitta; Walter, Stefan; Koenig, Thomas

2014-01-01

Performing a prospective memory task repeatedly changes the nature of the task from episodic to habitual. The goal of the present study was to investigate the neural basis of this transition. In two experiments, we contrasted event-related potentials (ERPs) evoked by correct responses to prospective memory targets in the first, more episodic part of the experiment with those of the second, more habitual part of the experiment. Specifically, we tested whether the early, middle, or late ERP-components, which are thought to reflect cue detection, retrieval of the intention, and post-retrieval processes, respectively, would be changed by routinely performing the prospective memory task. The results showed a differential ERP effect in the middle time window (450–650 ms post-stimulus). Source localization using low resolution brain electromagnetic tomography analysis suggests that the transition was accompanied by an increase of activation in the posterior parietal and occipital cortex. These findings indicate that habitual prospective memory involves retrieval processes guided more strongly by parietal brain structures. In brief, the study demonstrates that episodic and habitual prospective memory tasks recruit different brain areas. PMID:25071519

One declarative memory system or two? The relationship between episodic and semantic memory in children with temporal lobe epilepsy.

PubMed

Smith, Mary Lou; Lah, Suncica

2011-09-01

This study explored verbal semantic and episodic memory in children with unilateral temporal lobe epilepsy to determine whether they had impairments in both or only 1 aspect of memory, and to examine relations between performance in the 2 domains. Sixty-six children and adolescents (37 with seizures of left temporal lobe onset, 29 with right-sided onset) were given 4 tasks assessing different aspects of semantic memory (picture naming, fluency, knowledge of facts, knowledge of word meanings) and 2 episodic memory tasks (story recall, word list recall). High rates of impairments were observed across tasks, and no differences were found related to the laterality of the seizures. Individual patient analyses showed that there was a double dissociation between the 2 aspects of memory in that some children were impaired on episodic but not semantic memory, whereas others showed intact episodic but impaired semantic memory. This double dissociation suggests that these 2 memory systems may develop independently in the context of temporal lobe pathology, perhaps related to differential effects of dysfunction in the lateral and mesial temporal lobe structures. PsycINFO Database Record (c) 2011 APA, all rights reserved.

Recognition of Famous Names Predicts Episodic Memory Decline in Cognitively Intact Elders

PubMed Central

Seidenberg, Michael; Kay, Christina; Woodard, John L.; Nielson, Kristy A.; Smith, J. Carson; Kandah, Cassandra; Guidotti Breting, Leslie M.; Novitski, Julia; Lancaster, Melissa; Matthews, Monica; Hantke, Nathan; Butts, Alissa; Rao, Stephen M.

2013-01-01

Objective: Semantic memory impairment is common in both Mild Cognitive Impairment (MCI) and early Alzheimer’s disease (AD), and the ability to recognize familiar people is particularly vulnerable. A time-limited temporal gradient (TG) in which well known people from decades earlier are better recalled than those learned recently is also reported in both AD and MCI. In this study, we hypothesized that the TG pattern on a famous name recognition task (FNRT) administered to cognitively intact elders would predict future episodic memory decline, and would also show a significant correlation with hippocampal volume. Methods: 78 healthy elders (ages 65-90) with normal cognition and episodic memory at baseline were administered a FNRT. Follow-up episodic memory testing 18 months later produced two groups: Declining (≥ 1 SD reduction in episodic memory) and Stable (< 1 SD). Results: The Declining group (N=27) recognized fewer recent famous names than the Stable group (N=51), while recognition for remote names was comparable. Baseline MRI volumes for both the left and right hippocampus was significantly smaller in the Declining group than the Stable group. Smaller baseline hippocampal volume was also significantly correlated with poorer performance for recent, but not remote famous names. Logistic regression analyses indicated that baseline TG performance was a significant predictor of group status (Declining versus Stable) independent of chronological age and APOE ε4 inheritance. Conclusions: Famous name recognition may serve as an early pre-clinical cognitive marker of episodic memory decline in older individuals. PMID:23688215

Memory of occasional events in rats: individual episodic memory profiles, flexibility, and neural substrate.

PubMed

Veyrac, Alexandra; Allerborn, Marina; Gros, Alexandra; Michon, Frederic; Raguet, Louise; Kenney, Jana; Godinot, Florette; Thevenet, Marc; Garcia, Samuel; Messaoudi, Belkacem; Laroche, Serge; Ravel, Nadine

2015-05-13

In search for the mechanisms underlying complex forms of human memory, such as episodic recollection, a primary challenge is to develop adequate animal models amenable to neurobiological investigation. Here, we proposed a novel framework and paradigm that provides means to quantitatively evaluate the ability of rats to form and recollect a combined knowledge of what happened, where it happened, and when or in which context it happened (referred to as episodic-like memory) after a few specific episodes in situations as close as possible to a paradigm we recently developed to study episodic memory in humans. In this task, rats have to remember two odor-drink associations (what happened) encountered in distinct locations (where it happened) within two different multisensory enriched environments (in which context/occasion it happened), each characterized by a particular combination of odors and places. By analyzing licking behavior on each drinking port, we characterized quantitatively individual recollection profiles and showed that rats are able to incidentally form and recollect an accurate, long-term integrated episodic-like memory that can last ≥ 24 d after limited exposure to the episodes. Placing rats in a contextually challenging recollection situation at recall reveals the ability for flexible use of episodic memory as described in humans. We further report that reversible inactivation of the dorsal hippocampus during recall disrupts the animal's capacity to recollect the complete episodic memory. Cellular imaging of c-Fos and Zif268 brain activation reveals that episodic memory recollection recruits a specific, distributed network of hippocampal-prefrontal cortex structures that correlates with the accuracy of the integrated recollection performance. Copyright © 2015 the authors 0270-6474/15/337575-12$15.00/0.

Effects of age on a real-world What-Where-When memory task

PubMed Central

Mazurek, Adèle; Bhoopathy, Raja Meenakshi; Read, Jenny C. A.; Gallagher, Peter; Smulders, Tom V.

2015-01-01

Many cognitive abilities decline with aging, making it difficult to detect pathological changes against a background of natural changes in cognition. Most of the tests to assess cognitive decline are artificial tasks that have little resemblance to the problems faced by people in everyday life. This means both that people may have little practice doing such tasks (potentially contributing to the decline in performance) and that the tasks may not be good predictors of real-world cognitive problems. In this study, we test the performance of young people (18–25 years) and older people (60+-year-olds) on a novel, more ecologically valid test of episodic memory: the real-world What-Where-When (WWW) memory test. We also compare them on a battery of other cognitive tests, including working memory, psychomotor speed, executive function, and episodic memory. Older people show the expected age-related declines on the test battery. In the WWW memory task, older people were more likely to fail to remember any WWW combination than younger people were, although they did not significantly differ in their overall WWW score due to some older people performing as well as or better than most younger people. WWW memory performance was significantly predicted by other measures of episodic memory, such as the single-trial learning and long-term retention in the Rey Auditory Verbal Learning task and Combined Object Location Memory in the Object Relocation task. Self-reported memory complaints also predicted performance on the WWW task. These findings confirm that our real-world WWW memory task is a valid measure of episodic memory, with high ecological validity, which may be useful as a predictor of everyday memory abilities. The task will require a bit more development to improve its sensitivity to cognitive declines in aging and to potentially distinguish between mentally healthy older adults and those with early signs of cognitive pathologies. PMID:26042030

Role of slow oscillatory activity and slow wave sleep in consolidation of episodic-like memory in rats.

PubMed

Oyanedel, Carlos N; Binder, Sonja; Kelemen, Eduard; Petersen, Kimberley; Born, Jan; Inostroza, Marion

2014-12-15

Our previous experiments showed that sleep in rats enhances consolidation of hippocampus dependent episodic-like memory, i.e. the ability to remember an event bound into specific spatio-temporal context. Here we tested the hypothesis that this enhancing effect of sleep is linked to the occurrence of slow oscillatory and spindle activity during slow wave sleep (SWS). Rats were tested on an episodic-like memory task and on three additional tasks covering separately the where (object place recognition), when (temporal memory), and what (novel object recognition) components of episodic memory. In each task, the sample phase (encoding) was followed by an 80-min retention interval that covered either a period of regular morning sleep or sleep deprivation. Memory during retrieval was tested using preferential exploration of novelty vs. familiarity. Consistent with previous findings, the rats which had slept during the retention interval showed significantly stronger episodic-like memory and spatial memory, and a trend of improved temporal memory (although not significant). Object recognition memory was similarly retained across sleep and sleep deprivation retention intervals. Recall of episodic-like memory was associated with increased slow oscillatory activity (0.85-2.0Hz) during SWS in the retention interval. Spatial memory was associated with increased proportions of SWS. Against our hypothesis, a relationship between spindle activity and episodic-like memory performance was not detected, but spindle activity was associated with object recognition memory. The results provide support for the role of SWS and slow oscillatory activity in consolidating hippocampus-dependent memory, the role of spindles in this process needs to be further examined. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Higher body mass index is associated with episodic memory deficits in young adults.

PubMed

Cheke, Lucy G; Simons, Jon S; Clayton, Nicola S

2016-11-01

Obesity has become an international health crisis. There is accumulating evidence that excess bodyweight is associated with changes to the structure and function of the brain and with a number of cognitive deficits. In particular, research suggests that obesity is associated with hippocampal and frontal lobe dysfunction, which would be predicted to impact memory. However, evidence for such memory impairment is currently limited. We hypothesised that higher body mass index (BMI) would be associated with reduced performance on a test of episodic memory that assesses not only content, but also context and feature integration. A total of 50 participants aged 18-35 years, with BMIs ranging from 18 to 51, were tested on a novel what-where-when style episodic memory test: the "Treasure-Hunt Task". This test requires recollection of object, location, and temporal order information within the same paradigm, as well as testing the ability to integrate these features into a single event recollection. Higher BMI was associated with significantly lower performance on the what-where-when (WWW) memory task and all individual elements: object identification, location memory, and temporal order memory. After controlling for age, sex, and years in education, the effect of BMI on the individual what, where, and when tasks remained, while the WWW dropped below significance. This finding of episodic memory deficits in obesity is of concern given the emerging evidence for a role for episodic cognition in appetite regulation.

Higher body mass index is associated with episodic memory deficits in young adults

PubMed Central

Cheke, Lucy G.; Simons, Jon S.; Clayton, Nicola S.

2016-01-01

Obesity has become an international health crisis. There is accumulating evidence that excess bodyweight is associated with changes to the structure and function of the brain and with a number of cognitive deficits. In particular, research suggests that obesity is associated with hippocampal and frontal lobe dysfunction, which would be predicted to impact memory. However, evidence for such memory impairment is currently limited. We hypothesised that higher body mass index (BMI) would be associated with reduced performance on a test of episodic memory that assesses not only content, but also context and feature integration. A total of 50 participants aged 18–35 years, with BMIs ranging from 18 to 51, were tested on a novel what–where–when style episodic memory test: the “Treasure-Hunt Task”. This test requires recollection of object, location, and temporal order information within the same paradigm, as well as testing the ability to integrate these features into a single event recollection. Higher BMI was associated with significantly lower performance on the what–where–when (WWW) memory task and all individual elements: object identification, location memory, and temporal order memory. After controlling for age, sex, and years in education, the effect of BMI on the individual what, where, and when tasks remained, while the WWW dropped below significance. This finding of episodic memory deficits in obesity is of concern given the emerging evidence for a role for episodic cognition in appetite regulation. PMID:26447832

A Functional Examination of Intermediate Cognitive Processes.

DTIC Science & Technology

1986-01-01

memory ) and a body of accumulated information referred to as " semantic memory ". In contrast with episodic memory (which most psychological experiments...referents of input signals. (p. 386) But as Eysenck (1984) points out, there is "no precise dividing line" betveen episodic and semantic memory and although...involve), Tulving suggests that semantic memory is the more crucial to 5. .P, 31 performing everyday tasks: It is a mental thesaurus, the

Functional brain imaging of episodic memory decline in ageing.

PubMed

Nyberg, L

2017-01-01

The episodic long-term memory system supports remembering of events. It is considered to be the most age-sensitive system, with an average onset of decline around 60 years of age. However, there is marked interindividual variability, such that some individuals show faster than average change and others show no or very little change. This variability may be related to the risk of developing dementia, with elevated risk for individuals with accelerated episodic memory decline. Brain imaging with functional magnetic resonance imaging (MRI) of blood oxygen level-dependent (BOLD) signalling or positron emission tomography (PET) has been used to reveal the brain bases of declining episodic memory in ageing. Several studies have demonstrated a link between age-related episodic memory decline and the hippocampus during active mnemonic processing, which is further supported by studies of hippocampal functional connectivity in the resting state. The hippocampus interacts with anterior and posterior neocortical regions to support episodic memory, and alterations in hippocampus-neocortex connectivity have been shown to contribute to impaired episodic memory. Multimodal MRI studies and more recently hybrid MRI/PET studies allow consideration of various factors that can influence the association between the hippocampal BOLD signal and memory performance. These include neurovascular factors, grey and white matter structural alterations, dopaminergic neurotransmission, amyloid-Β and glucose metabolism. Knowledge about the brain bases of episodic memory decline can guide interventions to strengthen memory in older adults, particularly in those with an elevated risk of developing dementia, with promising results for combinations of cognitive and physical stimulation. © 2016 The Association for the Publication of the Journal of Internal Medicine.

Recall of Others' Actions after Incidental Encoding Reveals Episodic-like Memory in Dogs.

PubMed

Fugazza, Claudia; Pogány, Ákos; Miklósi, Ádám

2016-12-05

The existence of episodic memory in non-human animals is a debated topic that has been investigated using different methodologies that reflect diverse theoretical approaches to its definition. A fundamental feature of episodic memory is recalling after incidental encoding, which can be assessed if the recall test is unexpected [1]. We used a modified version of the "Do as I Do" method [2], relying on dogs' ability to imitate human actions, to test whether dogs can rely on episodic memory when recalling others' actions from the past. Dogs were first trained to imitate human actions on command. Next, they were trained to perform a simple training exercise (lying down), irrespective of the previously demonstrated action. This way, we substituted their expectation to be required to imitate with the expectation to be required to lie down. We then tested whether dogs recalled the demonstrated actions by unexpectedly giving them the command to imitate, instead of lying down. Dogs were tested with a short (1 min) and a long (1 hr) retention interval. They were able to recall the demonstrated actions after both intervals; however, their performance declined more with time compared to conditions in which imitation was expected. These findings show that dogs recall past events as complex as human actions even if they do not expect the memory test, providing evidence for episodic-like memory. Dogs offer an ideal model to study episodic memory in non-human species, and this methodological approach allows investigating memory of complex, context-rich events. VIDEO ABSTRACT. Copyright © 2016 Elsevier Ltd. All rights reserved.

Apolipoprotein E (APOE) ε4 and episodic memory decline in Alzheimer's disease: A review.

PubMed

El Haj, Mohamad; Antoine, Pascal; Amouyel, Philippe; Lambert, Jean-Charles; Pasquier, Florence; Kapogiannis, Dimitrios

2016-05-01

A growing body of research has examined the relationship between episodic memory decline, the cognitive hallmark of Alzheimer's disease (AD), and the presence of Apolipoprotein E ε4 (APOE ε4) allele, a major genetic risk factor for the disease. Our review attempts to summarize and critically evaluate this literature. We performed a systematic search for studies assessing episodic memory in AD patients who were genotyped for APOE ε4 and identified fourteen papers. Although most of these papers reported significant relationships between APOE ε4 and episodic memory decline in AD, some papers did not confirm this relationship. Our review links this controversy to the conflicting literature about the effects of APOE ε4 on general cognitive functioning in AD. We identify several shortcoming and limitations of the research on the relationship between APOE ε4 and episodic memory in AD, such as small sample sizes, non-representative populations, lack of comparison of early-onset vs. late-onset disease, and lack of comparison among different genotypes that include APOE ε4 (i.e., zero, one, or two ε4 alleles). Another major shortcoming of the reviewed literature was the lack of comprehensive evaluation of episodic memory decline, since episodic memory was solely evaluated with regard to encoding and retrieval, omitting evaluation of core episodic features that decline in AD, such as context recall (e.g., how, where, and when an episodic event has occurred) and subjective experience of remembering (e.g., reliving, emotion and feeling during episodic recollection). Future research taking these limitations into consideration could illuminate the nature of the relationship between APOE ε4 and episodic memory decline in AD. Copyright © 2016 Elsevier B.V. All rights reserved.

Encoding processes during retrieval tasks.

PubMed

Buckner, R L; Wheeler, M E; Sheridan, M A

2001-04-01

Episodic memory encoding is pervasive across many kinds of task and often arises as a secondary processing effect in tasks that do not require intentional memorization. To illustrate the pervasive nature of information processing that leads to episodic encoding, a form of incidental encoding was explored based on the "Testing" phenomenon: The incidental-encoding task was an episodic memory retrieval task. Behavioral data showed that performing a memory retrieval task was as effective as intentional instructions at promoting episodic encoding. During fMRI imaging, subjects viewed old and new words and indicated whether they remembered them. Relevant to encoding, the fate of the new words was examined using a second, surprise test of recognition after the imaging session. fMRI analysis of those new words that were later remembered revealed greater activity in left frontal regions than those that were later forgotten - the same pattern of results as previously observed for traditional incidental and intentional episodic encoding tasks. This finding may offer a partial explanation for why repeated testing improves memory performance. Furthermore, the observation of correlates of episodic memory encoding during retrieval tasks challenges some interpretations that arise from direct comparisons between "encoding tasks" and "retrieval tasks" in imaging data. Encoding processes and their neural correlates may arise in many tasks, even those nominally labeled as retrieval tasks by the experimenter.

Functional neuroanatomical associations of working memory in early-onset Alzheimer's disease.

PubMed

Kobylecki, Christopher; Haense, Cathleen; Harris, Jennifer M; Stopford, Cheryl L; Segobin, Shailendra H; Jones, Matthew; Richardson, Anna M T; Gerhard, Alexander; Anton-Rodriguez, José; Thompson, Jennifer C; Herholz, Karl; Snowden, Julie S

2018-01-01

To characterize metabolic correlates of working memory impairment in clinically defined subtypes of early-onset Alzheimer's disease. Established models of working memory suggest a key role for frontal lobe function, yet the association in Alzheimer's disease between working memory impairment and visuospatial and language symptoms suggests that temporoparietal neocortical dysfunction may be responsible. Twenty-four patients with predominantly early-onset Alzheimer's disease were clinically classified into groups with predominantly amnestic, multidomain or visual deficits. Patients underwent neuropsychological evaluation focused on the domains of episodic and working memory, T1-weighted magnetic resonance imaging and brain fluorodeoxyglucose positron emission tomography. Fluorodeoxyglucose positron emission tomography data were analysed by using a region-of-interest approach. Patients with multidomain and visual presentations performed more poorly on tests of working memory compared with amnestic Alzheimer's disease. Working memory performance correlated with glucose metabolism in left-sided temporoparietal, but not frontal neocortex. Carriers of the apolipoprotein E4 gene showed poorer episodic memory and better working memory performance compared with noncarriers. Our findings support the hypothesis that working memory changes in early-onset Alzheimer's disease are related to temporoparietal rather than frontal hypometabolism and show dissociation from episodic memory performance. They further support the concept of subtypes of Alzheimer's disease with distinct cognitive profiles due to prominent neocortical dysfunction early in the disease course. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Episodic but not semantic order memory difficulties in autism spectrum disorder: evidence from the Historical Figures Task.

PubMed

Gaigg, Sebastian B; Bowler, Dermot M; Gardiner, John M

2014-01-01

Considerable evidence suggests that the episodic memory system operates abnormally in autism spectrum disorder (ASD) whereas the functions of the semantic memory system are relatively preserved. Here we show that the same dissociation also applies to the domain of order memory. We asked adult participants to order the names of famous historical figures either according to their chronological order in history (probing semantic memory) or according to a random sequence shown once on a screen (probing episodic memory). As predicted, adults with ASD performed less well than age- and IQ-matched comparison individuals only on the episodic task. This observation is of considerable importance in the context of developmental theory because semantic and episodic order memory abilities can be dissociated in typically developing infants before they reach the age at which the behavioural markers associated with ASD are first apparent. This raises the possibility that early emerging memory abnormalities play a role in shaping the developmental trajectory of the disorder. We discuss the broader implications of this possibility and highlight the urgent need for greater scrutiny of memory competences in ASD early in development.

Age Invariance in Semantic and Episodic Metamemory: Both Younger and Older Adults Provide Accurate Feeling of Knowing For Names of Faces

PubMed Central

Eakin, Deborah K.; Hertzog, Christopher; Harris, William

2013-01-01

Age differences in feeling-of-knowing (FOK) accuracy were examined for both episodic memory and semantic memory. Younger and older adults either viewed pictures of famous faces (semantic memory) or associated nonfamous faces and names (episodic memory) and were tested on their memory for the name of the presented face. Participants viewed the faces again and made a FOK prediction about future recognition of the name associated with the presented face. Finally, four-alternative forced-choice recognition memory for the name, cued by the face, was tested and confidence judgments (CJs) were collected for each recognition response. Age differences were not obtained in semantic memory or the resolution of semantic FOKs, defined by within-person correlations of FOKs with recognition memory performance. Although age differences were obtained in level of episodic memory, there were no age differences in the resolution of episodic FOKs. FOKs for correctly recognized items correlated reliably with CJs for both types of materials, and did not differ by age group. The results indicate age invariance in monitoring of retrieval processes for name-face associations. PMID:23537379

Age invariance in semantic and episodic metamemory: both younger and older adults provide accurate feeling-of-knowing for names of faces.

PubMed

Eakin, Deborah K; Hertzog, Christopher; Harris, William

2014-01-01

Age differences in feeling-of-knowing (FOK) accuracy were examined for both episodic memory and semantic memory. Younger and older adults either viewed pictures of famous faces (semantic memory) or associated non-famous faces and names (episodic memory) and were tested on their memory for the name of the presented face. Participants viewed the faces again and made a FOK prediction about future recognition of the name associated with the presented face. Finally, four-alternative forced-choice recognition memory for the name, cued by the face, was tested and confidence judgments (CJs) were collected for each recognition response. Age differences were not obtained in semantic memory or the resolution of semantic FOKs, defined by within-person correlations of FOKs with recognition memory performance. Although age differences were obtained in level of episodic memory, there were no age differences in the resolution of episodic FOKs. FOKs for correctly recognized items correlated reliably with CJs for both types of materials, and did not differ by age group. The results indicate age invariance in monitoring of retrieval processes for name-face associations.

Using virtual reality to characterize episodic memory profiles in amnestic mild cognitive impairment and Alzheimer's disease: influence of active and passive encoding.

PubMed

Plancher, G; Tirard, A; Gyselinck, V; Nicolas, S; Piolino, P

2012-04-01

Most neuropsychological assessments of episodic memory bear little similarity to the events that patients actually experience as memories in daily life. The first aim of this study was to use a virtual environment to characterize episodic memory profiles in an ecological fashion, which includes memory for central and perceptual details, spatiotemporal contextual elements, and binding. This study included subjects from three different populations: healthy older adults, patients with amnestic mild cognitive impairment (aMCI) and patients with early to moderate Alzheimer's disease (AD). Second, we sought to determine whether environmental factors that can affect encoding (active vs. passive exploration) influence memory performance in pathological aging. Third, we benchmarked the results of our virtual reality episodic memory test against a classical memory test and a subjective daily memory complaint scale. Here, the participants were successively immersed in two virtual environments; the first, as the driver of a virtual car (active exploration) and the second, as the passenger of that car (passive exploration). Subjects were instructed to encode all elements of the environment as well as the associated spatiotemporal contexts. Following each immersion, we assessed the patient's recall and recognition of central information (i.e., the elements of the environment), contextual information (i.e., temporal, egocentric and allocentric spatial information) and lastly, the quality of binding. We found that the AD patients' performances were inferior to that of the aMCI and even more to that of the healthy aged groups, in line with the progression of hippocampal atrophy reported in the literature. Spatial allocentric memory assessments were found to be particularly useful for distinguishing aMCI patients from healthy older adults. Active exploration yielded enhanced recall of central and allocentric spatial information, as well as binding in all groups. This led aMCI patients to achieve better performance scores on immediate temporal memory tasks. Finally, the patients' daily memory complaints were more highly correlated with the performances on the virtual test than with their performances on the classical memory test. Taken together, these results highlight specific cognitive differences found between these three populations that may provide additional insight into the early diagnosis and rehabilitation of pathological aging. In particular, neuropsychological studies would benefit to use virtual tests and a multi-component approach to assess episodic memory, and encourage active encoding of information in patients suffering from mild or severe age-related memory impairment. The beneficial effect of active encoding on episodic memory in aMCI and early to moderate AD is discussed in the context of relatively preserved frontal and motor brain functions implicated in self-referential effects and procedural abilities. Copyright © 2011 Elsevier Ltd. All rights reserved.

The effect of hippocampal function, volume and connectivity on posterior cingulate cortex functioning during episodic memory fMRI in mild cognitive impairment.

PubMed

Papma, Janne M; Smits, Marion; de Groot, Marius; Mattace Raso, Francesco U; van der Lugt, Aad; Vrooman, Henri A; Niessen, Wiro J; Koudstaal, Peter J; van Swieten, John C; van der Veen, Frederik M; Prins, Niels D

2017-09-01

Diminished function of the posterior cingulate cortex (PCC) is a typical finding in early Alzheimer's disease (AD). It is hypothesized that in early stage AD, PCC functioning relates to or reflects hippocampal dysfunction or atrophy. The aim of this study was to examine the relationship between hippocampus function, volume and structural connectivity, and PCC activation during an episodic memory task-related fMRI study in mild cognitive impairment (MCI). MCI patients (n = 27) underwent episodic memory task-related fMRI, 3D-T1w MRI, 2D T2-FLAIR MRI and diffusion tensor imaging. Stepwise linear regression analysis was performed to examine the relationship between PCC activation and hippocampal activation, hippocampal volume and diffusion measures within the cingulum along the hippocampus. We found a significant relationship between PCC and hippocampus activation during successful episodic memory encoding and correct recognition in MCI patients. We found no relationship between the PCC and structural hippocampal predictors. Our results indicate a relationship between PCC and hippocampus activation during episodic memory engagement in MCI. This may suggest that during episodic memory, functional network deterioration is the most important predictor of PCC functioning in MCI. • PCC functioning during episodic memory relates to hippocampal functioning in MCI. • PCC functioning during episodic memory does not relate to hippocampal structure in MCI. • Functional network changes are an important predictor of PCC functioning in MCI.

The Episodic/Semantic Memory Distinction as an Heuristic in the Study of Instructional Effects on Cognitive Structure.

ERIC Educational Resources Information Center

Konold, Clifford E.; Bates, John A.

1982-01-01

Significant correlations between measures of cognitive structure and performance were found using a procedure distinguishing between episodic and semantic memory as an heuristic with achievement test items. The design increased the likelihood of indications of semantic memory. Higher-order and lower-order cognitive processes are discussed.…

The Latent Structure of Memory: A Confirmatory Factor-Analytic Study of Memory Distinctions.

ERIC Educational Resources Information Center

Herrman, Douglas J.; Schooler, Carmi; Caplan, Leslie J.; Lipman, Paula Darby; Grafman, Jordan; Schoenbach, Carrie; Schwab, Karen; Johnson, Marnie L.

2001-01-01

Used confirmatory factor analysis to study the nature of memory distinctions underlying the performance of two samples of Vietnam veterans. One sample (n=96) had received head injuries resulting in relatively small lesions; the other (n=85) had not. A four-component model with verbal-episodic, visual-episodic, semantic, and short-term memory…

Effects of selective serotonin reuptake and dual serotonergic-noradrenergic reuptake treatments on memory and mental processing speed in patients with major depressive disorder.

PubMed

Herrera-Guzmán, Ixchel; Gudayol-Ferré, Esteve; Herrera-Guzmán, Daniel; Guàrdia-Olmos, Joan; Hinojosa-Calvo, Erika; Herrera-Abarca, Jorge E

2009-06-01

Patients with major depressive disorder (MDD) usually suffer from altered cognitive functions of episodic memory, working memory, mental processing speed and motor response. Diverse studies suggest that different antidepressant agents may improve cognitive functions in patients with MDD. The aim of this work is to study the effects of serotonergic reuptake inhibitors (SSRIs) and serotonergic-noradrenergic reuptake inhibitors (SNRIs) treatments to improve the performance on memory tasks and mental processing speed in MDD. Seventy-three subjects meeting criteria for major depressive disorder were assessed with the Hamilton depression rating scale and a neuropsychological battery. The subjects were medicated with escitalopram (n=36) or duloxetine (n=37) for 24 weeks. At the end of the trial, the subjects were assessed again with the same neuropsychological battery used prior to the treatment. Both treatments improved importantly the episodic memory and to a lesser extent, working memory, mental processing speed and motor performance. Our results suggest that cognition is partially independent from improvement in clinical symptoms. Both groups achieved remission rates in the HAM-D-17 after 24 weeks of treatment, but SNRI was superior to SSRI at improving episodic and working memory. Our work indicates that the superiority of SNRI over the SSRI at episodic memory improvement is clinically relevant.

Evidence for a differential contribution of early perceptual and late cognitive processes during encoding to episodic memory impairment in schizophrenia.

PubMed

Green, Amity E; Fitzgerald, Paul B; Johnston, Patrick J; Nathan, Pradeep J; Kulkarni, Jayashri; Croft, Rodney J

2017-08-01

Schizophrenia is characterised by significant episodic memory impairment that is thought to be related to problems with encoding, however the neuro-functional mechanisms underlying these deficits are not well understood. The present study used a subsequent recognition memory paradigm and event-related potentials (ERPs) to investigate temporal aspects of episodic memory encoding deficits in schizophrenia. Electroencephalographic data was recorded in 24 patients and 19 healthy controls whilst participants categorised single words as pleasant/unpleasant. ERPs were generated to subsequently recognised versus unrecognised words on the basis of a forced-choice recognition memory task. Subsequent memory effects were examined with the late positive component (LPP). Group differences in N1, P2, N400 and LPP were examined for words correctly recognised. Patients performed more poorly than controls on the recognition task. During encoding patients had significantly reduced N400 and LPP amplitudes than controls. LPP amplitude correlated with task performance however amplitudes did not differ between patients and controls as a function of subsequent memory. No significant differences in N1 or P2 amplitude or latency were observed. The present results indicate that early sensory processes are intact and dysfunctional higher order cognitive processes during encoding are contributing to episodic memory impairments in schizophrenia.

Non-Verbal Episodic Memory Deficits in Primary Progressive Aphasias are Highly Predictive of Underlying Amyloid Pathology.

PubMed

Ramanan, Siddharth; Flanagan, Emma; Leyton, Cristian E; Villemagne, Victor L; Rowe, Christopher C; Hodges, John R; Hornberger, Michael

2016-01-01

Diagnostic distinction of primary progressive aphasias (PPA) remains challenging, in particular for the logopenic (lvPPA) and nonfluent/agrammatic (naPPA) variants. Recent findings highlight that episodic memory deficits appear to discriminate these PPA variants from each other, as only lvPPA perform poorly on these tasks while having underlying amyloid pathology similar to that seen in amnestic dementias like Alzheimer's disease (AD). Most memory tests are, however, language based and thus potentially confounded by the prevalent language deficits in PPA. The current study investigated this issue across PPA variants by contrasting verbal and non-verbal episodic memory measures while controlling for their performance on a language subtest of a general cognitive screen. A total of 203 participants were included (25 lvPPA; 29 naPPA; 59 AD; 90 controls) and underwent extensive verbal and non-verbal episodic memory testing, with a subset of patients (n = 45) with confirmed amyloid profiles as assessed by Pittsburgh Compound B and PET. The most powerful discriminator between naPPA and lvPPA patients was a non-verbal recall measure (Rey Complex Figure delayed recall), with 81% of PPA patients classified correctly at presentation. Importantly, AD and lvPPA patients performed comparably on this measure, further highlighting the importance of underlying amyloid pathology in episodic memory profiles. The findings demonstrate that non-verbal recall emerges as the best discriminator of lvPPA and naPPA when controlling for language deficits in high load amyloid PPA cases.

Spatial navigation, episodic memory, episodic future thinking, and theory of mind in children with autism spectrum disorder: evidence for impairments in mental simulation?

PubMed Central

Lind, Sophie E.; Bowler, Dermot M.; Raber, Jacob

2014-01-01

This study explored spatial navigation alongside several other cognitive abilities that are thought to share common underlying neurocognitive mechanisms (e.g., the capacity for self-projection, scene construction, or mental simulation), and which we hypothesized may be impaired in autism spectrum disorder (ASD). Twenty intellectually high-functioning children with ASD (with a mean age of ~8 years) were compared to 20 sex, age, IQ, and language ability matched typically developing children on a series of tasks to assess spatial navigation, episodic memory, episodic future thinking (also known as episodic foresight or prospection), theory of mind (ToM), relational memory, and central coherence. This is the first study to explore these abilities concurrently within the same sample. Spatial navigation was assessed using the “memory island” task, which involves finding objects within a realistic, computer simulated, three-dimensional environment. Episodic memory and episodic future thinking were assessed using a past and future event description task. ToM was assessed using the “animations” task, in which children were asked to describe the interactions between two animated triangles. Relational memory was assessed using a recognition task involving memory for items (line drawings), patterned backgrounds, or combinations of items and backgrounds. Central coherence was assessed by exploring differences in performance across segmented and unsegmented versions of block design. Children with ASD were found to show impairments in spatial navigation, episodic memory, episodic future thinking, and central coherence, but not ToM or relational memory. Among children with ASD, spatial navigation was found to be significantly negatively related to the number of repetitive behaviors. In other words, children who showed more repetitive behaviors showed poorer spatial navigation. The theoretical and practical implications of the results are discussed. PMID:25538661

Spatial navigation, episodic memory, episodic future thinking, and theory of mind in children with autism spectrum disorder: evidence for impairments in mental simulation?

PubMed

Lind, Sophie E; Bowler, Dermot M; Raber, Jacob

2014-01-01

This study explored spatial navigation alongside several other cognitive abilities that are thought to share common underlying neurocognitive mechanisms (e.g., the capacity for self-projection, scene construction, or mental simulation), and which we hypothesized may be impaired in autism spectrum disorder (ASD). Twenty intellectually high-functioning children with ASD (with a mean age of ~8 years) were compared to 20 sex, age, IQ, and language ability matched typically developing children on a series of tasks to assess spatial navigation, episodic memory, episodic future thinking (also known as episodic foresight or prospection), theory of mind (ToM), relational memory, and central coherence. This is the first study to explore these abilities concurrently within the same sample. Spatial navigation was assessed using the "memory island" task, which involves finding objects within a realistic, computer simulated, three-dimensional environment. Episodic memory and episodic future thinking were assessed using a past and future event description task. ToM was assessed using the "animations" task, in which children were asked to describe the interactions between two animated triangles. Relational memory was assessed using a recognition task involving memory for items (line drawings), patterned backgrounds, or combinations of items and backgrounds. Central coherence was assessed by exploring differences in performance across segmented and unsegmented versions of block design. Children with ASD were found to show impairments in spatial navigation, episodic memory, episodic future thinking, and central coherence, but not ToM or relational memory. Among children with ASD, spatial navigation was found to be significantly negatively related to the number of repetitive behaviors. In other words, children who showed more repetitive behaviors showed poorer spatial navigation. The theoretical and practical implications of the results are discussed.

Behavioral Performance and Neural Areas Associated with Memory Processes Contribute to Math and Reading Achievement in 6-year-old Children.

PubMed

Blankenship, Tashauna L; Keith, Kayla; Calkins, Susan D; Bell, Martha Ann

2018-01-01

Associations between working memory and academic achievement (math and reading) are well documented. Surprisingly, little is known of the contributions of episodic memory, segmented into temporal memory (recollection proxy) and item recognition (familiarity proxy), to academic achievement. This is the first study to observe these associations in typically developing 6-year old children. Overlap in neural correlates exists between working memory, episodic memory, and math and reading achievement. We attempted to tease apart the neural contributions of working memory, temporal memory, and item recognition to math and reading achievement. Results suggest that working memory and temporal memory, but not item recognition, are important contributors to both math and reading achievement, and that EEG power during a working memory task contributes to performance on tests of academic achievement.

Prospective and retrospective episodic metamemory in posttraumatic stress disorder.

PubMed

Sacher, Mathilde; Tudorache, Andrei-Cristian; Clarys, David; Boudjarane, Mohamed; Landré, Lionel; El-Hage, Wissam

2018-03-14

Posttraumatic stress disorder (PTSD) has been consistently associated with episodic memory deficits. To some extent, these deficits could be related to an impairment of metamemory in individuals with PTSD. This research consequently aims at investigating prospective (feeling-of-knowing, FOK) and retrospective (confidence) metamemory judgments for episodic information in PTSD. Twenty participants with PTSD and without depression were compared to 30 healthy comparison participants on metamemory judgments during an episodic memory task. The concordance between metamemory judgments and recognition performance was then assessed by gamma correlations. The results confirmed that PTSD is associated with episodic memory impairment. Regarding metamemory, gamma correlations indicated that participants with PTSD failed to accurately predict their future memory performance as compared to the comparison group (mean FOK gamma correlations: .23 vs. .42, respectively). Furthermore, participants with PTSD made less accurate confidence judgments than comparison participants (mean confidence gamma correlations: .62 vs. .74, respectively). Our results demonstrate an alteration of both prospective and retrospective metamemory processes in PTSD, which could be of particular relevance to future therapeutic interventions focusing on metacognitive strategies.

Medial temporal lobe structure and cognition in individuals with schizophrenia and in their non-psychotic siblings.

PubMed

Karnik-Henry, Meghana S; Wang, Lei; Barch, Deanna M; Harms, Michael P; Campanella, Carolina; Csernansky, John G

2012-07-01

Medial temporal lobe (MTL) structures play a central role in episodic memory. Prior studies suggest that individuals with schizophrenia have deficits in episodic memory as well as structural abnormalities of the medial temporal lobe (MTL). While correlations have been reported between MTL volume loss and episodic memory deficits in such individuals, it is not clear whether such correlations reflect the influence of the disease state or of underlying genetic influences that might contribute to risk. We used high resolution magnetic resonance imaging and probabilistic algorithms for image analysis to determine whether MTL structure, episodic memory performance and the relationship between the two differed among groups of 47 healthy control subjects, 50 control siblings, 39 schizophrenia subjects, and 33 siblings of schizophrenia subjects. High-dimensional large deformation brain mapping was used to obtain volume measures of the hippocampus. Cortical distance mapping was used to obtain volume and thickness measures of the parahippocampal gyrus (PHG) and its substructures: the entorhinal cortex (ERC), the perirhinal cortex (PRC), and the parahippocampal cortex (PHC). Neuropsychological data was used to establish an episodic memory domain score for each subject. Both schizophrenia subjects and their siblings displayed abnormalities in episodic memory performance. Siblings of individuals with schizophrenia, and to a lesser extent, individuals with schizophrenia themselves, displayed abnormalities in measures of MTL structure (volume loss or cortical thinning) as compared to control groups. Further, we observed correlations between structural measures and memory performance in both schizophrenia subjects and their siblings, but not in their respective control groups. These findings suggest that disease-specific genetic factors present in both patients and their relatives may be responsible for correlated abnormalities of MTL structure and memory impairment. The observed attenuated effect of such factors on MTL structure in individuals with schizophrenia may be due to non-genetic influences related to the development and progression of the disease on global brain structure and cognitive processing. Copyright © 2012 Elsevier B.V. All rights reserved.

Genetic Analysis of Association Between Calcium Signaling and Hippocampal Activation, Memory Performance in the Young and Old, and Risk for Sporadic Alzheimer Disease.

PubMed

Heck, Angela; Fastenrath, Matthias; Coynel, David; Auschra, Bianca; Bickel, Horst; Freytag, Virginie; Gschwind, Leo; Hartmann, Francina; Jessen, Frank; Kaduszkiewicz, Hanna; Maier, Wolfgang; Milnik, Annette; Pentzek, Michael; Riedel-Heller, Steffi G; Spalek, Klara; Vogler, Christian; Wagner, Michael; Weyerer, Siegfried; Wolfsgruber, Steffen; de Quervain, Dominique J-F; Papassotiropoulos, Andreas

2015-10-01

Human episodic memory performance is linked to the function of specific brain regions, including the hippocampus; declines as a result of increasing age; and is markedly disturbed in Alzheimer disease (AD), an age-associated neurodegenerative disorder that primarily affects the hippocampus. Exploring the molecular underpinnings of human episodic memory is key to the understanding of hippocampus-dependent cognitive physiology and pathophysiology. To determine whether biologically defined groups of genes are enriched in episodic memory performance across age, memory encoding-related brain activity, and AD. In this multicenter collaborative study, which began in August 2008 and is ongoing, gene set enrichment analysis was done by using primary and meta-analysis data from 57 968 participants. The Swiss cohorts consisted of 3043 healthy young adults assessed for episodic memory performance. In a subgroup (n = 1119) of one of these cohorts, functional magnetic resonance imaging was used to identify gene set-dependent differences in brain activity related to episodic memory. The German Study on Aging, Cognition, and Dementia in Primary Care Patients cohort consisted of 763 elderly participants without dementia who were assessed for episodic memory performance. The International Genomics of Alzheimer's Project case-control sample consisted of 54 162 participants (17 008 patients with sporadic AD and 37 154 control participants). Analyses were conducted between January 2014 and June 2015. Gene set enrichment analysis in all samples was done using genome-wide single-nucleotide polymorphism data. Episodic memory performance in the Swiss cohort and German Study on Aging, Cognition, and Dementia in Primary Care Patients cohort was quantified by picture and verbal delayed free recall tasks. In the functional magnetic resonance imaging experiment, activation of the hippocampus during encoding of pictures served as the phenotype of interest. In the International Genomics of Alzheimer's Project sample, diagnosis of sporadic AD served as the phenotype of interest. In the discovery sample, we detected significant enrichment for genes constituting the calcium signaling pathway, especially those related to the elevation of cytosolic calcium (P = 2 × 10-4). This enrichment was replicated in 2 additional samples of healthy young individuals (P = .02 and .04, respectively) and a sample of healthy elderly participants (P = .004). Hippocampal activation (P = 4 × 10-4) and the risk for sporadic AD (P = .01) were also significantly enriched for genes related to the elevation of cytosolic calcium. By detecting consistent significant enrichment in independent cohorts of young and elderly participants, this study identified that calcium signaling plays a central role in hippocampus-dependent human memory processes in cognitive health and disease, contributing to the understanding and potential treatment of hippocampus-dependent cognitive pathology.

Entorhinal Tau Pathology, Episodic Memory Decline, and Neurodegeneration in Aging.

PubMed

Maass, Anne; Lockhart, Samuel N; Harrison, Theresa M; Bell, Rachel K; Mellinger, Taylor; Swinnerton, Kaitlin; Baker, Suzanne L; Rabinovici, Gil D; Jagust, William J

2018-01-17

The medial temporal lobe (MTL) is an early site of tau accumulation and MTL dysfunction may underlie episodic-memory decline in aging and dementia. Postmortem data indicate that tau pathology in the transentorhinal cortex is common by age 60, whereas spread to neocortical regions and worsening of cognition is associated with β-amyloid (Aβ). We used [ 18 F]AV-1451 and [ 11 C]PiB positron emission tomography, structural MRI, and neuropsychological assessment to investigate how in vivo tau accumulation in temporal lobe regions, Aβ, and MTL atrophy contribute to episodic memory in cognitively normal older adults ( n = 83; age, 77 ± 6 years; 58% female). Stepwise regressions identified tau in MTL regions known to be affected in old age as the best predictor of episodic-memory performance independent of Aβ status. There was no interactive effect of MTL tau with Aβ on memory. Higher MTL tau was related to higher age in the subjects without evidence of Aβ. Among temporal lobe subregions, episodic memory was most strongly related to tau-tracer uptake in the parahippocampal gyrus, particularly the posterior entorhinal cortex, which in our parcellation includes the transentorhinal cortex. In subjects with longitudinal MRI and cognitive data ( n = 57), entorhinal atrophy mirrored patterns of tau pathology and their relationship with memory decline. Our data are consistent with neuropathological studies and further suggest that entorhinal tau pathology underlies memory decline in old age even without Aβ. SIGNIFICANCE STATEMENT Tau tangles and β-amyloid (Aβ) plaques are key lesions in Alzheimer's disease (AD) but both pathologies also occur in cognitively normal older people. Neuropathological data indicate that tau tangles in the medial temporal lobe (MTL) underlie episodic-memory impairments in AD dementia. However, it remains unclear whether MTL tau pathology also accounts for memory impairments often seen in elderly people and how Aβ affects this relationship. Using tau-specific and Aβ-specific positron emission tomography tracers, we show that in vivo MTL tau pathology is associated with episodic-memory performance and MTL atrophy in cognitively normal adults, independent of Aβ. Our data point to MTL tau pathology, particularly in the entorhinal cortex, as a substrate of age-related episodic-memory loss. Copyright © 2018 the authors 0270-6474/18/380530-14$15.00/0.

Functional connectivity of hippocampal and prefrontal networks during episodic and spatial memory based on real-world environments.

PubMed

Robin, Jessica; Hirshhorn, Marnie; Rosenbaum, R Shayna; Winocur, Gordon; Moscovitch, Morris; Grady, Cheryl L

2015-01-01

Several recent studies have compared episodic and spatial memory in neuroimaging paradigms in order to understand better the contribution of the hippocampus to each of these tasks. In the present study, we build on previous findings showing common neural activation in default network areas during episodic and spatial memory tasks based on familiar, real-world environments (Hirshhorn et al. (2012) Neuropsychologia 50:3094-3106). Following previous demonstrations of the presence of functionally connected sub-networks within the default network, we performed seed-based functional connectivity analyses to determine how, depending on the task, the hippocampus and prefrontal cortex differentially couple with one another and with distinct whole-brain networks. We found evidence for a medial prefrontal-parietal network and a medial temporal lobe network, which were functionally connected to the prefrontal and hippocampal seeds, respectively, regardless of the nature of the memory task. However, these two networks were functionally connected with one another during the episodic memory task, but not during spatial memory tasks. Replicating previous reports of fractionation of the default network into stable sub-networks, this study also shows how these sub-networks may flexibly couple and uncouple with one another based on task demands. These findings support the hypothesis that episodic memory and spatial memory share a common medial temporal lobe-based neural substrate, with episodic memory recruiting additional prefrontal sub-networks. © 2014 Wiley Periodicals, Inc.

Egocentric-updating during navigation facilitates episodic memory retrieval.

PubMed

Gomez, Alice; Rousset, Stéphane; Baciu, Monica

2009-11-01

Influential models suggest that spatial processing is essential for episodic memory [O'Keefe, J., & Nadel, L. (1978). The hippocampus as a cognitive map. London: Oxford University Press]. However, although several types of spatial relations exist, such as allocentric (i.e. object-to-object relations), egocentric (i.e. static object-to-self relations) or egocentric updated on navigation information (i.e. self-to-environment relations in a dynamic way), usually only allocentric representations are described as potentially subserving episodic memory [Nadel, L., & Moscovitch, M. (1998). Hippocampal contributions to cortical plasticity. Neuropharmacology, 37(4-5), 431-439]. This study proposes to confront the allocentric representation hypothesis with an egocentric updated with self-motion representation hypothesis. In the present study, we explored retrieval performance in relation to these two types of spatial processing levels during learning. Episodic remembering has been assessed through Remember responses in a recall and in a recognition task, combined with a "Remember-Know-Guess" paradigm [Gardiner, J. M. (2001). Episodic memory and autonoetic consciousness: A first-person approach. Philosophical Transactions of the Royal Society B: Biological Sciences, 356(1413), 1351-1361] to assess the autonoetic level of responses. Our results show that retrieval performance was significantly higher when encoding was performed in the egocentric-updated condition. Although egocentric updated with self-motion and allocentric representations are not mutually exclusive, these results suggest that egocentric updating processing facilitates remember responses more than allocentric processing. The results are discussed according to Burgess and colleagues' model of episodic memory [Burgess, N., Becker, S., King, J. A., & O'Keefe, J. (2001). Memory for events and their spatial context: models and experiments. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 356(1413), 1493-1503].

Assessing the role of memory in preschoolers' performance on episodic foresight tasks.

PubMed

Atance, Cristina M; Sommerville, Jessica A

2014-01-01

A total of 48 preschoolers (ages 3, 4, and 5) received four tasks modelled after prior work designed to assess the development of "episodic foresight". For each task, children encountered a problem in one room and, after a brief delay, were given the opportunity in a second room to select an item to solve the problem. Importantly, after selecting an item, children were queried about their memory for the problem. Age-related changes were found both in children's ability to select the correct item and their ability to remember the problem. However, when we controlled for children's memory for the problem, there were no longer significant age-related changes on the item choice measure. These findings suggest that age-related changes in children's performance on these tasks are driven by improvements in children's memory versus improvements in children's future-oriented thinking or "foresight" per se. Our results have important implications for how best to structure tasks to measure children's episodic foresight, and also for the relative role of memory in this task and in episodic foresight more broadly.

Enhanced effects of cortisol administration on episodic and working memory in aging veterans with PTSD.

PubMed

Yehuda, Rachel; Harvey, Philip D; Buchsbaum, Monte; Tischler, Lisa; Schmeidler, James

2007-12-01

Though both glucocorticoid alterations and memory impairments have been noted in posttraumatic stress disorder (PTSD), it is not clear if these phenomena are causally linked. As there is emerging evidence that these domains become further altered in PTSD with increasing age, it is of interest to examine these relationships in an older cohort. Aging (mean age, 62.7+/-8.9; range, 52-81) combat veterans with (n=13) and without (n=17) PTSD received an intravenous bolus of 17.5 mg hydrocortisone (cortisol), a naturally occurring glucocorticoid, or placebo in a randomized, double-blind manner, on two mornings approximately 1-2 weeks apart. Neuropsychological testing to evaluate episodic and working memory performance was performed 75 min later. Cortisol enhanced episodic memory performance in both groups of subjects, but enhanced elements of working memory performance only in the PTSD+ group. The preferential effect of cortisol administration on working memory in PTSD may be related to the superimposition of PTSD and age, as cortisol had impairing effects on this task in a previously studied, younger cohort. The findings suggest that there may be opportunities for developing therapeutic strategies using glucocorticoids in the treatment of aging combat veterans.

Relationships between episodic memory performance prediction and sociodemographic variables among healthy older adults.

PubMed

de Oliveira, Glaucia Martins; Cachioni, Meire; Falcão, Deusivania; Batistoni, Samila; Lopes, Andrea; Guimarães, Vanessa; Lima-Silva, Thais Bento; Neri, Anita Liberalesso; Yassuda, Mônica Sanches

2015-01-01

Previous studies have suggested that performance prediction, an aspect of metamemory, may be associated with objective performance on memory tasks. The objective of the study was to describe memory prediction before performing an episodic memory task, in community-dwelling older adults, stratified by sex, age group and educational level. Additionally, the association between predicted and objective performance on a memory task was investigated. The study was based on data from 359 participants in the FIBRA study carried out at Ermelino Matarazzo, São Paulo. Memory prediction was assessed by posing the question: "If someone showed you a sheet with drawings of 10 pictures to observe for 30 seconds, how many pictures do you think you could remember without seeing the sheet?". Memory performance was assessed by the memorization of 10 black and white pictures from the Brief Cognitive Screening Battery (BCSB). No differences were found between men and women, nor for age group and educational level, in memory performance prediction before carrying out the memory task. There was a modest association (rho=0.11, p=0.041) between memory prediction and performance in immediate memory. On multivariate linear regression analyses, memory performance prediction was moderately significantly associated with immediate memory (p=0.061). In this study, sociodemographic variables did not influence memory prediction, which was only modestly associated with immediate memory on the Brief Cognitive Screening Battery (BCSB).

The optimal timing of stimulation to induce long-lasting positive effects on episodic memory in physiological aging.

PubMed

Manenti, Rosa; Sandrini, Marco; Brambilla, Michela; Cotelli, Maria

2016-09-15

Episodic memory displays the largest degree of age-related decline. A noninvasive brain stimulation technique that can be used to modulate memory in physiological aging is transcranial Direct Current Stimulation (tDCS). However, an aspect that has not been adequately investigated in previous studies is the optimal timing of stimulation to induce long-lasting positive effects on episodic memory function. Our previous studies showed episodic memory enhancement in older adults when anodal tDCS was applied over the left lateral prefrontal cortex during encoding or after memory consolidation with or without a contextual reminder. Here we directly compared the two studies to explore which of the tDCS protocols would induce longer-lasting positive effects on episodic memory function in older adults. In addition, we aimed to determine whether subjective memory complaints would be related to the changes in memory performance (forgetting) induced by tDCS, a relevant issue in aging research since individuals with subjective memory complaints seem to be at higher risk of later memory decline. The results showed that anodal tDCS applied after consolidation with a contextual reminder induced longer-lasting positive effects on episodic memory, conceivably through reconsolidation, than anodal tDCS during encoding. Furthermore, we reported, providing new data, a moderate negative correlation between subjective memory complaints and forgetting when anodal tDCS was applied after consolidation with a contextual reminder. This study sheds light on the best-suited timing of stimulation to induce long-lasting positive effects on memory function and might help the clinicians to select the most effective tDCS protocol to prevent memory decline. Copyright © 2016 Elsevier B.V. All rights reserved.

Deficits in episodic memory are related to uncontrolled eating in a sample of healthy adults.

PubMed

Martin, A A; Davidson, T L; McCrory, M A

2018-05-01

Despite a substantial amount of animal data linking deficits in memory inhibition to the development of overeating and obesity, few studies have investigated the relevance of memory inhibition to uncontrolled eating in humans. Further, although memory for recent eating has been implicated as an important contributor to satiety and energy intake, the possibility that variations in episodic memory relate to individual differences in food intake control has been largely neglected. To examine these relationships, we recruited ninety-three adult subjects to attend a single lab session where we assessed body composition, dietary intake, memory performance, and eating behaviors (Three Factor Eating Questionnaire). Episodic recall and memory inhibition were assessed using a well-established measure of memory interference (Retrieval Practice Paradigm). Hierarchical regression analyses indicated that memory inhibition was largely unrelated to participants' eating behaviors; however, episodic recall was reliably predicted by restrained vs. uncontrolled eating: recall was positively associated with strategic dieting (β = 2.45, p = 0.02), avoidance of fatty foods (β = 3.41, p = 0.004), and cognitive restraint (β = 1.55, p = 0.04). In contrast, recall was negatively associated with uncontrolled eating (β = -1.15, p = 0.03) and emotional eating (β = -2.46, p = 0.04). These findings suggest that episodic memory processing is related to uncontrolled eating in humans. The possibility that deficits in episodic memory may contribute to uncontrolled eating by disrupting memory for recent eating is discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Encoding-related brain activity during deep processing of verbal materials: a PET study.

PubMed

Fujii, Toshikatsu; Okuda, Jiro; Tsukiura, Takashi; Ohtake, Hiroya; Suzuki, Maki; Kawashima, Ryuta; Itoh, Masatoshi; Fukuda, Hiroshi; Yamadori, Atsushi

2002-12-01

The recent advent of neuroimaging techniques provides an opportunity to examine brain regions related to a specific memory process such as episodic memory encoding. There is, however, a possibility that areas active during an assumed episodic memory encoding task, compared with a control task, involve not only areas directly relevant to episodic memory encoding processes but also areas associated with other cognitive processes for on-line information. We used positron emission tomography (PET) to differentiate these two kinds of regions. Normal volunteers were engaged in deep (semantic) or shallow (phonological) processing of new or repeated words during PET. Results showed that deep processing, compared with shallow processing, resulted in significantly better recognition performance and that this effect was associated with activation of various brain areas. Further analyses revealed that there were regions directly relevant to episodic memory encoding in the anterior part of the parahippocampal gyrus, inferior frontal gyrus, supramarginal gyrus, anterior cingulate gyrus, and medial frontal lobe in the left hemisphere. Our results demonstrated that several regions, including the medial temporal lobe, play a role in episodic memory encoding.

The Integration of Realistic Episodic Memories Relies on Different Working Memory Processes: Evidence from Virtual Navigation.

PubMed

Plancher, Gaën; Gyselinck, Valérie; Piolino, Pascale

2018-01-01

Memory is one of the most important cognitive functions in a person's life as it is essential for recalling personal memories and performing many everyday tasks. Although a huge number of studies have been conducted in the field, only a few of them investigated memory in realistic situations, due to methodological issues. The various tools that have been developed using virtual environments (VEs) have gained popularity in cognitive psychology and neuropsychology because they enable to create naturalistic and controlled situations, and are thus particularly adapted to the study of episodic memory (EM), for which an ecological evaluation is of prime importance. EM is the conscious recollection of personal events combined with their phenomenological and spatiotemporal encoding contexts. Using an original paradigm in a VE, the objective of the present study was to characterize the construction of episodic memories. While the concept of working memory has become central in the understanding of a wide range of cognitive functions, its role in the integration of episodic memories has seldom been assessed in an ecological context. This experiment aimed at filling this gap by studying how EM is affected by concurrent tasks requiring working memory resources in a realistic situation. Participants navigated in a virtual town and had to memorize as many elements in their spatiotemporal context as they could. During learning, participants had either to perform a concurrent task meant to prevent maintenance through the phonological loop, or a task aimed at preventing maintenance through the visuospatial sketchpad, or no concurrent task. EM was assessed in a recall test performed after learning through various scores measuring the what, where and when of the memories. Results showed that, compared to the control condition with no concurrent task, the prevention of maintenance through the phonological loop had a deleterious impact only on the encoding of central elements. By contrast, the prevention of visuo-spatial maintenance interfered both with the encoding of the temporal context and with the binding. These results suggest that the integration of realistic episodic memories relies on different working memory processes that depend on the nature of the traces.

Preserved recognition in a case of developmental amnesia: implications for the acquisition of semantic memory?

PubMed

Baddeley, A; Vargha-Khadem, F; Mishkin, M

2001-04-01

We report the performance on recognition memory tests of Jon, who, despite amnesia from early childhood, has developed normal levels of performance on tests of intelligence, language, and general knowledge. Despite impaired recall, he performed within the normal range on each of six recognition tests, but he appears to lack the recollective phenomenological experience normally associated with episodic memory. His recall of previously unfamiliar newsreel events was impaired, but gained substantially from repetition over a 2-day period. Our results are consistent with the hypothesis that the recollective process of episodic memory is not necessary either for recognition or for the acquisition of semantic knowledge.

Measuring episodic memory across the lifespan: NIH Toolbox Picture Sequence Memory Test.

PubMed

Dikmen, Sureyya S; Bauer, Patricia J; Weintraub, Sandra; Mungas, Dan; Slotkin, Jerry; Beaumont, Jennifer L; Gershon, Richard; Temkin, Nancy R; Heaton, Robert K

2014-07-01

Episodic memory is one of the most important cognitive domains that involves acquiring, storing and recalling new information. In this article, we describe a new measure developed for the NIH Toolbox, called the Picture Sequence Memory Test (PSMT) that is the first to examine episodic memory across the age range from 3 to 85. We describe the development of the measure and present validation data for ages 20 to 85. The PSMT involves presentation of sequences of pictured objects and activities in a fixed order on a computer screen and simultaneously verbally described, that the participant must remember and then reproduce over three learning trials. The results indicate good test-retest reliability and construct validity. Performance is strongly related to well-established "gold standard" measures of episodic memory and, as expected, much less well correlated with those of a measure of vocabulary. It shows clear decline with aging in parallel with a gold standard summary measure and relates to several other demographic factors and to self-reported general health status. The PSMT appears to be a reliable and valid test of episodic memory for adults, a finding similar to those found for the same measure with children.

Remote memory in a patient with amnesia due to hypoxia.

PubMed

Beatty, W W; Salmon, D P; Bernstein, N; Butters, N

1987-08-01

It has been suggested that amnesic patients suffer a selective loss of episodic memory while semantic memory remains well preserved. To assess the validity of this idea we studied remote memory in an amnesic patient, (M.R.L.), using several different measures that differ in the extent to which they engage episodic or semantic memory. On two different versions of the Albert et al. (1979) remote memory battery M.R.L. displayed severe retrograde amnesia (RA) extending backwards in time for about 15 years with excellent preservation of older memories. With standard recall instructions his overall performance on the Crovitz test of autobiographical memory was impaired and all of M.R.L.'s specific, temporally dated memories were given from the first half of his life. When asked to reconstruct his past residential history in detail, M.R.L. provide specific and generally accurate information for residences occupied from his boyhood until 1970, but thereafter his memory became quite unreliable. On a test of knowledge of terms commonly employed in the surveying profession, in which he worked for the past 20 years, M.R.L.'s performance was also impaired. The consistent pattern of RA displayed by this patient on all of the tests of remote memory indicates that both episodic and semantic memory are impaired in amnesia.

Less Effort, Better Results: How Does Music Act on Prefrontal Cortex in Older Adults during Verbal Encoding? An fNIRS Study.

PubMed

Ferreri, Laura; Bigand, Emmanuel; Perrey, Stephane; Muthalib, Makii; Bard, Patrick; Bugaiska, Aurélia

2014-01-01

Several neuroimaging studies of cognitive aging revealed deficits in episodic memory abilities as a result of prefrontal cortex (PFC) limitations. Improving episodic memory performance despite PFC deficits is thus a critical issue in aging research. Listening to music stimulates cognitive performance in several non-purely musical activities (e.g., language and memory). Thus, music could represent a rich and helpful source during verbal encoding and therefore help subsequent retrieval. Furthermore, such benefit could be reflected in less demand of PFC, which is known to be crucial for encoding processes. This study aimed to investigate whether music may improve episodic memory in older adults while decreasing the PFC activity. Sixteen healthy older adults (μ = 64.5 years) encoded lists of words presented with or without a musical background while their dorsolateral prefrontal cortex (DLPFC) activity was monitored using a eight-channel continuous-wave near-infrared spectroscopy (NIRS) system (Oxymon Mk III, Artinis, The Netherlands). Behavioral results indicated a better source-memory performance for words encoded with music compared to words encoded with silence (p < 0.05). Functional NIRS data revealed bilateral decrease of oxyhemoglobin values in the music encoding condition compared to the silence condition (p < 0.05), suggesting that music modulates the activity of the DLPFC during encoding in a less-demanding direction. Taken together, our results indicate that music can help older adults in memory performances by decreasing their PFC activity. These findings open new perspectives about music as tool for episodic memory rehabilitation on special populations with memory deficits due to frontal lobe damage such as Alzheimer's patients.

Less Effort, Better Results: How Does Music Act on Prefrontal Cortex in Older Adults during Verbal Encoding? An fNIRS Study

PubMed Central

Ferreri, Laura; Bigand, Emmanuel; Perrey, Stephane; Muthalib, Makii; Bard, Patrick; Bugaiska, Aurélia

2014-01-01

Several neuroimaging studies of cognitive aging revealed deficits in episodic memory abilities as a result of prefrontal cortex (PFC) limitations. Improving episodic memory performance despite PFC deficits is thus a critical issue in aging research. Listening to music stimulates cognitive performance in several non-purely musical activities (e.g., language and memory). Thus, music could represent a rich and helpful source during verbal encoding and therefore help subsequent retrieval. Furthermore, such benefit could be reflected in less demand of PFC, which is known to be crucial for encoding processes. This study aimed to investigate whether music may improve episodic memory in older adults while decreasing the PFC activity. Sixteen healthy older adults (μ = 64.5 years) encoded lists of words presented with or without a musical background while their dorsolateral prefrontal cortex (DLPFC) activity was monitored using a eight-channel continuous-wave near-infrared spectroscopy (NIRS) system (Oxymon Mk III, Artinis, The Netherlands). Behavioral results indicated a better source-memory performance for words encoded with music compared to words encoded with silence (p < 0.05). Functional NIRS data revealed bilateral decrease of oxyhemoglobin values in the music encoding condition compared to the silence condition (p < 0.05), suggesting that music modulates the activity of the DLPFC during encoding in a less-demanding direction. Taken together, our results indicate that music can help older adults in memory performances by decreasing their PFC activity. These findings open new perspectives about music as tool for episodic memory rehabilitation on special populations with memory deficits due to frontal lobe damage such as Alzheimer’s patients. PMID:24860481

Flynn Effects on Sub-Factors of Episodic and Semantic Memory: Parallel Gains over Time and the Same Set of Determining Factors

ERIC Educational Resources Information Center

Ronnlund, Michael; Nilsson, Lars-Goran.

2009-01-01

The study examined the extent to which time-related gains in cognitive performance, so-called Flynn effects, generalize across sub-factors of episodic memory (recall and recognition) and semantic memory (knowledge and fluency). We conducted time-sequential analyses of data drawn from the Betula prospective cohort study, involving four age-matched…

Subjective memory complaint only relates to verbal episodic memory performance in mild cognitive impairment.

PubMed

Gifford, Katherine A; Liu, Dandan; Damon, Stephen M; Chapman, William G; Romano Iii, Raymond R; Samuels, Lauren R; Lu, Zengqi; Jefferson, Angela L

2015-01-01

A cognitive concern from the patient, informant, or clinician is required for the diagnosis of mild cognitive impairment (MCI); however, the cognitive and neuroanatomical correlates of complaint are poorly understood. We assessed how self-complaint relates to cognitive and neuroimaging measures in older adults with MCI. MCI participants were drawn from the Alzheimer's Disease Neuroimaging Initiative and dichotomized into two groups based on the presence of self-reported memory complaint (no complaint n = 191, 77 ± 7 years; complaint n = 206, 73 ± 8 years). Cognitive outcomes included episodic memory, executive functioning, information processing speed, and language. Imaging outcomes included regional lobar volumes (frontal, parietal, temporal, cingulate) and specific medial temporal lobe structures (hippocampal volume, entorhinal cortex thickness, parahippocampal gyrus thickness). Linear regressions, adjusting for age, gender, race, education, Mini-Mental State Examination score, mood, and apolipoprotein E4 status, found that cognitive complaint related to immediate (β = -1.07, p < 0.001) and delayed episodic memory performances assessed on a serial list learning task (β = -1.06, p = 0.001) but no other cognitive measures or neuroimaging markers. Self-reported memory concern was unrelated to structural neuroimaging markers of atrophy and measures of information processing speed, executive functioning, or language. In contrast, subjective memory complaint related to objective verbal episodic learning performance. Future research is warranted to better understand the relation between cognitive complaint and surrogate markers of abnormal brain aging, including Alzheimer's disease, across the cognitive aging spectrum.

CE verbal episodic memory impairment in schizophrenia: a comparison with frontal lobe lesion patients.

PubMed

Christensen, Bruce K; Patrick, Regan E; Stuss, Donald T; Gillingham, Susan; Zipursky, Robert B

2013-01-01

Schizophrenia (SCZ)-related verbal memory impairment is hypothesized to be mediated, in part, by frontal lobe (FTL) dysfunction. However, little research has contrasted the performance of SCZ patients with that of patients exhibiting circumscribed frontal lesions. The current study compared verbal episodic memory in patients with SCZ and focal FTL lesions (left frontal, LF; right frontal, RF; and bi-frontal, BF) on a four-trial list learning task consisting of three lists of varying semantic organizational structure. Each dependent variable was examined at two levels: scores collapsed across all four trials and learning scores (i.e., trial 4-trial 1). Performance deficits were observed in each patient group across most dependent measures at both levels. Regarding patient group differences, SCZ patients outperformed LF/BF patients (i.e., either learning scores or scores collapsed across trial) on free recall, primacy, primary memory, secondary memory, and subjective organization, whereas they only outperformed RF patients on the semantically blocked list on recency and primary memory. Collectively, these results indicate that the pattern of memory performance is largely similar between patients with SCZ and those with RF lesions. These data support tentative arguments that verbal episodic memory deficits in SCZ may be mediated by frontal dysfunction in the right hemisphere.

Use of immersive virtual reality to assess episodic memory: A validation study in older adults.

PubMed

Corriveau Lecavalier, Nick; Ouellet, Émilie; Boller, Benjamin; Belleville, Sylvie

2018-05-29

Virtual reality (VR) allows for the creation of ecological environments that could be used for cognitive assessment and intervention. This study comprises two parts that describe and assess an immersive VR task, the Virtual Shop, which can be used to measure episodic memory. Part 1 addresses its applicability in healthy older adults by measuring presence, motivation, and cybersickness symptoms. Part 2 addresses its construct validity by investigating correlations between performance in the VR task and on a traditional experimental memory task, and by measuring whether the VR task is sensitive to age-related memory differences. Fifty-seven older and 20 younger adults were assessed in the Virtual Shop, in which they memorised and fetched 12 familiar items. Part 1 showed high levels of presence, higher levels of motivation for the VR than for the traditional task, and negligible cybersickness symptoms. Part 2 indicates that memory performance in the VR task is positively correlated with performance on a traditional memory task for both age groups, and age-related differences were found on the VR and traditional memory tasks. Thus, the use of VR is feasible in older adults and the Virtual Shop is a valid task to assess and train episodic memory in this population.

Declarative memory.

PubMed

Riedel, Wim J; Blokland, Arjan

2015-01-01

Declarative Memory consists of memory for events (episodic memory) and facts (semantic memory). Methods to test declarative memory are key in investigating effects of potential cognition-enhancing substances--medicinal drugs or nutrients. A number of cognitive performance tests assessing declarative episodic memory tapping verbal learning, logical memory, pattern recognition memory, and paired associates learning are described. These tests have been used as outcome variables in 34 studies in humans that have been described in the literature in the past 10 years. Also, the use of episodic tests in animal research is discussed also in relation to the drug effects in these tasks. The results show that nutritional supplementation of polyunsaturated fatty acids has been investigated most abundantly and, in a number of cases, but not all, show indications of positive effects on declarative memory, more so in elderly than in young subjects. Studies investigating effects of registered anti-Alzheimer drugs, cholinesterase inhibitors in mild cognitive impairment, show positive and negative effects on declarative memory. Studies mainly carried out in healthy volunteers investigating the effects of acute dopamine stimulation indicate enhanced memory consolidation as manifested specifically by better delayed recall, especially at time points long after learning and more so when drug is administered after learning and if word lists are longer. The animal studies reveal a different picture with respect to the effects of different drugs on memory performance. This suggests that at least for episodic memory tasks, the translational value is rather poor. For the human studies, detailed parameters of the compositions of word lists for declarative memory tests are discussed and it is concluded that tailored adaptations of tests to fit the hypothesis under study, rather than "off-the-shelf" use of existing tests, are recommended.

Prospective and Episodic Memory in Relation to Hippocampal Volume in Adults with Spina Bifida Myelomeningocele

PubMed Central

Treble-Barna, Amery; Juranek, Jenifer; Stuebing, Karla K.; Cirino, Paul T.; Dennis, Maureen; Fletcher, Jack M.

2014-01-01

The present study examined prospective and episodic memory in relation to age, functional independence, and hippocampal volume in younger to middle-aged adults with spina bifida myelomeningocele (SBM) and typically developing (TD) adults. Prospective and episodic memory, as well as hippocampal volume, were reduced in adults with SBM relative to TD adults. Neither memory performance nor hippocampal volume showed greater decrements in older adults. Lower hippocampal volume was associated with reduced prospective memory in adults with SBM, and this relation was specific to the hippocampus and not to a contrast structure, the amygdala. Prospective memory mediated the relation between hippocampal volume and functional independence in adults with SBM. The results add to emerging evidence for reduced memory function in adults with SBM, and provide quantitative evidence for compromised hippocampal macrostructure as a neural correlate of reduced memory in this population. PMID:25068670

Replay of Episodic Memories in the Rat.

PubMed

Panoz-Brown, Danielle; Iyer, Vishakh; Carey, Lawrence M; Sluka, Christina M; Rajic, Gabriela; Kestenman, Jesse; Gentry, Meredith; Brotheridge, Sydney; Somekh, Isaac; Corbin, Hannah E; Tucker, Kjersten G; Almeida, Bianca; Hex, Severine B; Garcia, Krysten D; Hohmann, Andrea G; Crystal, Jonathon D

2018-05-21

Vivid episodic memories in people have been characterized as the replay of multiple unique events in sequential order [1-3]. The hippocampus plays a critical role in episodic memories in both people and rodents [2, 4-6]. Although rats remember multiple unique episodes [7, 8], it is currently unknown if animals "replay" episodic memories. Therefore, we developed an animal model of episodic memory replay. Here, we show that rats can remember a trial-unique stream of multiple episodes and the order in which these events occurred by engaging hippocampal-dependent episodic memory replay. We document that rats rely on episodic memory replay to remember the order of events rather than relying on non-episodic memories. Replay of episodic memories survives a long retention-interval challenge and interference from the memory of other events, which documents that replay is part of long-term episodic memory. The chemogenetic activating drug clozapine N-oxide (CNO), but not vehicle, reversibly impairs episodic memory replay in rats previously injected bilaterally in the hippocampus with a recombinant viral vector containing an inhibitory designer receptor exclusively activated by a designer drug (DREADD; AAV8-hSyn-hM4Di-mCherry). By contrast, two non-episodic memory assessments are unaffected by CNO, showing selectivity of this hippocampal-dependent impairment. Our approach provides an animal model of episodic memory replay, a process by which the rat searches its representations in episodic memory in sequential order to find information. Our findings using rats suggest that the ability to replay a stream of episodic memories is quite old in the evolutionary timescale. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Episodic Buffer in Children with Intellectual Disabilities: An Exploratory Study

ERIC Educational Resources Information Center

Henry, Lucy A.

2010-01-01

Performance on three verbal measures (story recall, paired associated learning, category fluency) designed to assess the integration of long-term semantic and linguistic knowledge, phonological working memory and executive resources within the proposed "episodic buffer" of working memory (Baddeley, 2007) was assessed in children with intellectual…

Episodic Memory Retrieval Functionally Relies on Very Rapid Reactivation of Sensory Information.

PubMed

Waldhauser, Gerd T; Braun, Verena; Hanslmayr, Simon

2016-01-06

Episodic memory retrieval is assumed to rely on the rapid reactivation of sensory information that was present during encoding, a process termed "ecphory." We investigated the functional relevance of this scarcely understood process in two experiments in human participants. We presented stimuli to the left or right of fixation at encoding, followed by an episodic memory test with centrally presented retrieval cues. This allowed us to track the reactivation of lateralized sensory memory traces during retrieval. Successful episodic retrieval led to a very early (∼100-200 ms) reactivation of lateralized alpha/beta (10-25 Hz) electroencephalographic (EEG) power decreases in the visual cortex contralateral to the visual field at encoding. Applying rhythmic transcranial magnetic stimulation to interfere with early retrieval processing in the visual cortex led to decreased episodic memory performance specifically for items encoded in the visual field contralateral to the site of stimulation. These results demonstrate, for the first time, that episodic memory functionally relies on very rapid reactivation of sensory information. Remembering personal experiences requires a "mental time travel" to revisit sensory information perceived in the past. This process is typically described as a controlled, relatively slow process. However, by using electroencephalography to measure neural activity with a high time resolution, we show that such episodic retrieval entails a very rapid reactivation of sensory brain areas. Using transcranial magnetic stimulation to alter brain function during retrieval revealed that this early sensory reactivation is causally relevant for conscious remembering. These results give first neural evidence for a functional, preconscious component of episodic remembering. This provides new insight into the nature of human memory and may help in the understanding of psychiatric conditions that involve the automatic intrusion of unwanted memories. Copyright © 2016 the authors 0270-6474/16/360251-10$15.00/0.

Neural Activations of Guided Imagery and Music in Negative Emotional Processing: A Functional MRI Study.

PubMed

Lee, Sang Eun; Han, Yeji; Park, HyunWook

2016-01-01

The Bonny Method of Guided Imagery and Music uses music and imagery to access and explore personal emotions associated with episodic memories. Understanding the neural mechanism of guided imagery and music (GIM) as combined stimuli for emotional processing informs clinical application. We performed functional magnetic resonance imaging (fMRI) to demonstrate neural mechanisms of GIM for negative emotional processing when personal episodic memory is recalled and re-experienced through GIM processes. Twenty-four healthy volunteers participated in the study, which used classical music and verbal instruction stimuli to evoke negative emotions. To analyze the neural mechanism, activated regions associated with negative emotional and episodic memory processing were extracted by conducting volume analyses for the contrast between GIM and guided imagery (GI) or music (M). The GIM stimuli showed increased activation over the M-only stimuli in five neural regions associated with negative emotional and episodic memory processing, including the left amygdala, left anterior cingulate gyrus, left insula, bilateral culmen, and left angular gyrus (AG). Compared with GI alone, GIM showed increased activation in three regions associated with episodic memory processing in the emotional context, including the right posterior cingulate gyrus, bilateral parahippocampal gyrus, and AG. No neural regions related to negative emotional and episodic memory processing showed more activation for M and GI than for GIM. As a combined multimodal stimulus, GIM may increase neural activations related to negative emotions and episodic memory processing. Findings suggest a neural basis for GIM with personal episodic memories affecting cortical and subcortical structures and functions. © the American Music Therapy Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Episodic Memory and Regional Atrophy in Frontotemporal Lobar Degeneration

PubMed Central

Söderlund, Hedvig; Black, Sandra E.; Miller, Bruce L.; Freedman, Morris; Levine, Brian

2008-01-01

It has been unclear to what extent memory is affected in frontotemporal lobar degeneration (FTLD). Since patients usually have atrophy in regions implicated in memory function, the frontal and/or temporal lobes, one would expect some memory impairment, and that the degree of atrophy in these regions would be inversely related to memory function. The purposes of this study were 1) to assess episodic memory function in FTLD, and more specifically patients' ability to episodically re-experience an event, and determine its source; 2) to examine whether memory performance is related to quantified regional brain atrophy. FTLD patients (n=18) and healthy comparison subjects (n=14) were assessed with cued recall, recognition, “remember/know” (self-reported re-experiencing) and source recall, at 30 min and 24 hr after encoding. Regional gray matter volumes were assessed with high resolution structural MRI concurrently to testing. Patients performed worse than comparison subjects on all memory measures. Gray matter volume in the left medial temporal lobe was positively correlated with recognition, re-experiencing, and source recall. Gray matter volume in the left posterior temporal lobe correlated significantly with recognition, at 30 min and 24 hr, and with source recall at 30 min. Estimated familiarity at 30 min was positively correlated with gray matter volume in the left inferior parietal lobe. In summary, episodic memory deficits in FTLD may be more common than previously thought, particularly in patients with left medial and posterior temporal atrophy. PMID:17888461

Job strain and trajectories of change in episodic memory before and after retirement: results from the Health and Retirement Study.

PubMed

Andel, Ross; Infurna, Frank J; Hahn Rickenbach, Elizabeth A; Crowe, Michael; Marchiondo, Lisa; Fisher, Gwenith G

2015-05-01

We examined indicators of job strain in relation to level and change in episodic memory in the years leading up to as well as following retirement. Our analyses centre on 3779 individuals from the nationally representative Health and Retirement Study (baseline age 57.3 years) who reported gainful employment in an occupation for 10+ years prior to retirement, and who were assessed for episodic memory performance over up to 20 years (median 8 waves over 16 years). We used ratings from the Occupational Information Network (O*Net) to score occupations for job control and job demands, and to measure job strain (job demands/job control). Controlling for sociodemographic characteristics, depressive symptoms, and cardiovascular disease, less job control and greater job strain were not significantly associated with change in episodic memory in the period leading up to retirement, but were associated with significantly poorer episodic memory at retirement and an accelerated rate of decline in episodic memory following retirement. The results did not vary for men and women or by self-employment status. Job strain expressed mainly as low job control is linked to poorer episodic memory at retirement and more decline after retirement. Job characteristics appear to have implications for cognitive ageing independent of relevant confounds. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Working memory and executive functions in transient global amnesia.

PubMed

Quinette, Peggy; Guillery, Bérengère; Desgranges, Béatrice; de la Sayette, Vincent; Viader, Fausto; Eustache, Francis

2003-09-01

Transient global amnesia (TGA) is usually considered to produce a profound impairment of long-term episodic memory, while at the same time sparing working memory. However, this neuropsychological dissociation has rarely been examined in detail. While a few studies have assessed some components of working memory in TGA, the results that have been obtained are far from conclusive. To clarify this issue, we carried out a comprehensive investigation of working memory in 10 patients during a TGA attack. In the first study, we report the results from three patients examined with a battery of neuropsychological tests designed to assess each of the three subcomponents of Baddeley's model of working memory. In a second study, seven different patients underwent neuropsychological investigations that focused specifically on the central executive system, using a protocol derived from a study by Miyake and colleagues. Our findings showed that subcomponents of working memory, such as the phonological loop and visuo-spatial sketch pad, were spared in TGA patients. Specific executive functions that entailed inhibitory control, dual task performance, updating and shifting mechanisms were also found to be normal. However, we found significantly impaired performance for the Brown-Peterson test, and that TGA patients were significantly impaired in the recollection of their episodic memories. They also made reduced numbers of 'remember' compared with 'know' judgments in the episodic memory test several days after TGA. On the basis of our findings, it would appear that the episodic memory deficit during TGA is not related to elementary aspects of executive functioning. Our data also highlight the nature of the cognitive mechanisms involved in the Brown-Peterson task, which may well depend on long-term memory (such as the process of semantic encoding). Lastly, the selective deficit in recollective episodic memories observed in TGA may be principally related to medial temporal lobe abnormalities that have been reported in this syndrome.

The influence of encoding strategy on episodic memory and cortical activity in schizophrenia.

PubMed

Bonner-Jackson, Aaron; Haut, Kristen; Csernansky, John G; Barch, Deanna M

2005-07-01

Recent work suggests that episodic memory deficits in schizophrenia may be related to disturbances of encoding or retrieval. Schizophrenia patients appear to benefit from instruction in episodic memory strategies. We tested the hypothesis that providing effective encoding strategies to schizophrenia patients enhances encoding-related brain activity and recognition performance. Seventeen schizophrenia patients and 26 healthy comparison subjects underwent functional magnetic resonance imaging scans while performing incidental encoding tasks of words and faces. Subjects were required to make either deep (abstract/concrete) or shallow (alphabetization) judgments for words and deep (gender) judgments for faces, followed by subsequent recognition tests. Schizophrenia and comparison subjects recognized significantly more words encoded deeply than shallowly, activated regions in inferior frontal cortex (Brodmann area 45/47) typically associated with deep and successful encoding of words, and showed greater left frontal activation for the processing of words compared with faces. However, during deep encoding and material-specific processing (words vs. faces), participants with schizophrenia activated regions not activated by control subjects, including several in prefrontal cortex. Our findings suggest that a deficit in use of effective strategies influences episodic memory performance in schizophrenia and that abnormalities in functional brain activation persist even when such strategies are applied.

Proactive interference and concurrent inhibitory processes do not differentially affect item and associative recognition: Implication for the age-related associative memory deficit.

PubMed

Guez, Jonathan; Naveh-Benjamin, Moshe

2016-09-01

Previous studies have suggested an associative deficit hypothesis [Naveh-Benjamin, M. ( 2000 ). Adult age differences in memory performance: Tests of an associative deficit hypothesis. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 1170-1187] to explain age-related episodic memory declines. The hypothesis attributes part of the deficient episodic memory performance in older adults to a difficulty in creating and retrieving cohesive episodes. In this article, we further evaluate this hypothesis by testing two alternative processes that potentially mediate associative memory deficits in older adults. Four experiments are presented that assess whether failure of inhibitory processes (proactive interference in Experiments 1 and 2), and concurrent inhibition (in Experiments 3 and 4) are mediating factors in age-related associative deficits. The results suggest that creating conditions that require the operation of inhibitory processes, or that interfere with such processes, cannot simulate associative memory deficit in older adults. Instead, such results support the idea that associative memory deficits reflect a unique binding failure in older adults. This failure seems to be independent of other cognitive processes, including inhibitory and other resource-demanding processes.

Perspectives on Episodic-Like and Episodic Memory

PubMed Central

Pause, Bettina M.; Zlomuzica, Armin; Kinugawa, Kiyoka; Mariani, Jean; Pietrowsky, Reinhard; Dere, Ekrem

2013-01-01

Episodic memory refers to the conscious recollection of a personal experience that contains information on what has happened and also where and when it happened. Recollection from episodic memory also implies a kind of first-person subjectivity that has been termed autonoetic consciousness. Episodic memory is extremely sensitive to cerebral aging and neurodegenerative diseases. In Alzheimer’s disease deficits in episodic memory function are among the first cognitive symptoms observed. Furthermore, impaired episodic memory function is also observed in a variety of other neuropsychiatric diseases including dissociative disorders, schizophrenia, and Parkinson disease. Unfortunately, it is quite difficult to induce and measure episodic memories in the laboratory and it is even more difficult to measure it in clinical populations. Presently, the tests used to assess episodic memory function do not comply with even down-sized definitions of episodic-like memory as a memory for what happened, where, and when. They also require sophisticated verbal competences and are difficult to apply to patient populations. In this review, we will summarize the progress made in defining behavioral criteria of episodic-like memory in animals (and humans) as well as the perspectives in developing novel tests of human episodic memory which can also account for phenomenological aspects of episodic memory such as autonoetic awareness. We will also define basic behavioral, procedural, and phenomenological criteria which might be helpful for the development of a valid and reliable clinical test of human episodic memory. PMID:23616754

Bilateral Parietal Cortex Damage Does Not Impair Associative Memory for Paired Stimuli

PubMed Central

Berryhill, Marian E.; Drowos, David B.; Olson, Ingrid R.

2010-01-01

Recent neuroimaging and neuropsychological findings indicate that the posterior parietal cortex (PPC) plays an important, albeit undefined, role in episodic memory. Here we ask whether this region is specifically involved in associative aspects of episodic memory. Experiment 1 tested whether PPC damage affects the ability to learn and retrieve novel word-pair associations. Experiment 2 tested whether PPC damage affects the retrieval of object-location associations, in a spatial fan task. In both experiments, patients showed normal levels of associative memory. These findings demonstrated that PPC damage did not prevent association memory for verbal items. Finally Experiment 3 tested whether PPC damage affects memory for non-verbal audio-visual pairs. The patients performed with normal accuracy, but with significantly reduced confidence. These findings indicate that the PPC does not have a central role in association formation per se and instead, indicate that the PPC is involved in other aspects of episodic memory. PMID:20104378

Episodic Memory in Alzheimer Disease, Frontotemporal Dementia, and Dementia With Lewy Bodies/Parkinson Disease Dementia: Disentangling Retrieval From Consolidation.

PubMed

Economou, Alexandra; Routsis, Christopher; Papageorgiou, Sokratis G

2016-01-01

Differences in episodic memory performance in patients with Alzheimer disease (AD), frontotemporal dementia (FTD), dementia with Lewy bodies (DLB)/Parkinson disease with dementia (PDD) are inconsistent and task dependent. The inconsistencies may be attributed to the different tasks drawing on different memory processes. Few studies have examined episodic memory impairment in the above groups using memory tests that facilitate encoding, to distinguish memory deficits due to impairment of specific processes. We examined the memory performance of 106 AD patients, 51 FTD patients, 26 DLB/PDD patients, and 37 controls using the Five-Words Test, a 5-item memory test that facilitates encoding. The patient groups did not differ in modified Mini Mental State Examination scores. AD patients scored lowest on the Five-Words Test overall, and showed the greatest reduction from immediate total recall to delayed free recall relative to the other 2 groups, consistent with a predominantly consolidation deficit. DLB/PDD patients showed the largest improvement from delayed free to delayed total recall relative to the other 2 groups, consistent with a predominantly retrieval deficit. Deficits in both consolidation and retrieval underlie the memory impairment of the patients, to different extents, and contribute to the theoretical understanding of the nature of the memory impairment of the patient groups.

Gender-Specific Differences in the Relationship between Autobiographical Memory and Intertemporal Choice in Older Adults

PubMed Central

Seinstra, Maayke; Grzymek, Katharina; Kalenscher, Tobias

2015-01-01

As the population of older adults grows, their economic choices will have increasing impact on society. Research on the effects of aging on intertemporal decisions shows inconsistent, often opposing results, indicating that yet unexplored factors might play an essential role in guiding one's choices. Recent studies suggest that episodic future thinking, which is based on the same neural network involved in episodic memory functions, leads to reductions in discounting of future rewards. As episodic memory functioning declines with normal aging, but to greatly variable degrees, individual differences in delay discounting might be due to individual differences in the vitality of this memory system in older adults. We investigated this hypothesis, using a sample of healthy older adults who completed an intertemporal choice task as well as two episodic memory tasks. We found no clear evidence for a relationship between episodic memory performance and delay discounting in older adults. However, when additionally considering gender differences, we found an interaction effect of gender and autobiographical memory on delay discounting: while men with higher memory scores showed less delay discounting, women with higher memory scores tended to discount the future more. We speculate that this gender effect might stem from the gender-specific use of different modal representation formats (i.e. temporal or visual) during assessment of intertemporal choice options. PMID:26335426

Temporal context memory in high-functioning autism.

PubMed

Gras-Vincendon, Agnès; Mottron, Laurent; Salamé, Pierre; Bursztejn, Claude; Danion, Jean-Marie

2007-11-01

Episodic memory, i.e. memory for specific episodes situated in space and time, seems impaired in individuals with autism. According to weak central coherence theory, individuals with autism have general difficulty connecting contextual and item information which then impairs their capacity to memorize information in context. This study investigated temporal context memory for visual information in individuals with autism. Eighteen adolescents and adults with high-functioning autism (HFA) or Asperger syndrome (AS) and age- and IQ-matched typically developing participants were tested using a recency judgement task. The performance of the autistic group did not differ from that of the control group, nor did the performance between the AS and HFA groups. We conclude that autism in high-functioning individuals does not impair temporal context memory as assessed on this task. We suggest that individuals with autism are as efficient on this task as typically developing subjects because contextual memory performance here involves more automatic than organizational processing.

Source Memory in Korsakoff Syndrome: Disentangling the Mechanisms of Temporal Confusion.

PubMed

Brion, Mélanie; de Timary, Philippe; Pitel, Anne-Lise; Maurage, Pierre

2017-03-01

Korsakoff syndrome (KS), most frequently resulting from alcohol dependence (ALC), is characterized by severe anterograde amnesia. It has been suggested that these deficits may extend to other memory components, and notably source memory deficits involved in the disorientation and temporal confusion frequently observed in KS. However, the extent of this source memory impairment in KS and its usefulness for the differential diagnosis between ALC and KS remain unexplored. Nineteen patients with KS were compared with 19 alcohol-dependent individuals and 19 controls in a source memory test exploring temporal context confusions ("continuous recognition task"). Episodic memory and psychopathological comorbidities were controlled for. While no source memory deficit was observed in ALC, KS was associated with a significant presence of temporal context confusion, even when the influence of comorbidities was taken into account. This source memory impairment did not appear to be related to performances on episodic memory or executive functions. Patients with KS displayed source memory deficits, as indexed by temporal context confusions. The absence of a relationship with episodic memory performances seems to indicate that source memory impairment is not a mere by-product of amnesia. As ALC was associated with preserved source memory, the presence of temporal context confusion may serve as a complementary tool for the differential diagnosis between ALC and KS. Copyright © 2017 by the Research Society on Alcoholism.

Altered prefrontal brain activity in persons at risk for Alzheimer's disease: an fMRI study.

PubMed

Elgh, Eva; Larsson, Anne; Eriksson, Sture; Nyberg, Lars

2003-06-01

Early diagnosis of Alzheimer's disease (AD) is critical for adequate treatment and care. Recently it has been shown that functional magnetic resonance imaging (fMRI) can be important in preclinical detection of AD. The purpose of this study was to examine possible differences in memory-related brain activation between persons with high versus low risk for AD. This was achieved by combining a validated neurocognitive screening battery (the 7-minutes test) with memory assessment and fMRI. One hundred two healthy community-living persons with subjective memory complaints were recruited through advertisement and tested with the 7-minutes test. Based on their test performance they were classified as having either high (n = 8) or low risk (n = 94) for AD. Six high-risk individuals and six age-, sex-, and education-matched low-risk individuals were investigated with fMRI while engaged in episodic memory tasks. The high-risk individuals performed worse than low-risk individuals on tests of episodic memory. Patterns of brain activity during episodic encoding and retrieval showed significant group differences (p < .05 corrected). During both encoding and retrieval, the low-risk persons showed increased activity relative to a baseline condition in prefrontal brain regions that previously have been implicated in episodic memory. By contrast, the high-risk persons did not significantly activate any prefrontal regions, but instead showed increased activity in visual occipito-temporal regions. Patterns of prefrontal brain activity related to episodic memory differ between persons with high versus low risk for AD, and lowered prefrontal activity may predict subsequent disease.

Inter-Individual Variation in Fronto-Temporal Connectivity Predicts the Ability to Learn Different Types of Associations

PubMed Central

Alm, Kylie H.; Rolheiser, Tyler; Olson, Ingrid R.

2016-01-01

The uncinate fasciculus connects portions of the anterior and medial temporal lobes to the lateral orbitofrontal cortex, so it has long been thought that this limbic fiber pathway plays an important role in episodic memory. Some types of episodic memory are impaired after damage to the uncinate, while others remain intact. Because of this, the specific role played by the uncinate fasciculus in episodic memory remains undetermined. In the present study, we tested the hypothesis that the uncinate fasciculus is involved in episodic memory tasks that have high competition between representations at retrieval. To test this hypothesis, healthy young adults performed three tasks: Experiment 1 in which they learned to associate names with faces through feedback provided at the end of each trial; Experiment 2 in which they learned to associate fractals with cued locations through feedback provided at the end of each trial; and Experiment 3 in which unique faces were remembered in a paradigm with low retrieval competition. Diffusion tensor imaging and deterministic tractography methods were used to extract measures of uncinate fasciculus microstructure. Results revealed that microstructural properties of the uncinate, but not a control tract, the inferior longitudinal fasciculus, significantly predicted individual differences in performance on the face-name and fractal-location tasks. However, no relationship was observed for simple face memory (Experiment 3). These findings suggest that the uncinate fasciculus may be important for adjudicating between competing memory representations at the time of episodic retrieval. PMID:26908315

Strategy difficulty effects in young and older adults' episodic memory are modulated by inter-stimulus intervals and executive control processes.

PubMed

Burger, Lucile; Uittenhove, Kim; Lemaire, Patrick; Taconnat, Laurence

2017-04-01

Efficient execution of strategies is crucial to memory performance and to age-related differences in this performance. Relative strategy complexity influences memory performance and aging effects on memory. Here, we aimed to further our understanding of the effects of relative strategy complexity by looking at the role of cognitive control functions and the time-course of the effects of relative strategy complexity. Thus, we manipulated inter-stimulus intervals (ISI) and assessed executive functions. Results showed that (a) performance as a function of the relative strategy difficulty of the current and previous trial was modulated by ISI, (b) these effects were modulated by inhibition capacities, and (c) significant age differences were found in the way ISI modulates relative strategy difficulty. These findings have important implications for understanding the relationships between aging, executive control, and strategy execution in episodic memory. Copyright © 2017 Elsevier B.V. All rights reserved.

Impaired category fluency in medial temporal lobe amnesia: the role of episodic memory.

PubMed

Greenberg, Daniel L; Keane, Margaret M; Ryan, Lee; Verfaellie, Mieke

2009-09-02

Memory tasks are often classified as semantic or episodic, but recent research shows that these types of memory are highly interactive. Category fluency, for example, is generally considered to reflect retrieval from semantic memory, but behavioral evidence suggests that episodic memory is also involved: participants frequently draw on autobiographical experiences while generating exemplars of certain categories. Neuroimaging studies accordingly have reported increased medial temporal lobe (MTL) activation during exemplar generation. Studies of fluency in MTL amnesics have yielded mixed results but were not designed to determine the precise contributions of episodic memory. We addressed this issue by asking MTL amnesics and controls to generate exemplars of three types of categories. One type tended to elicit autobiographical and spatial retrieval strategies (AS). Another type elicited strategies that were autobiographical but nonspatial (AN). The third type elicited neither autobiographical nor spatial strategies (N). Amnesic patients and control participants generated exemplars for eight categories of each type. Patients were impaired on all category types but were more impaired on AS and AN categories. After covarying for phonemic fluency (total FAS score), the N category impairment was not significant, but the impairment on AS and AN categories remained. The same results were obtained for patients with lesions restricted to the MTL and those with more extensive lesions. We conclude that patients' episodic memory impairment hindered their performance on this putatively semantic task. This interaction between episodic and semantic memory might partially account for fluency deficits seen in aging, mild cognitive impairment, and Alzheimer's disease.

Memory sources of dreams: the incorporation of autobiographical rather than episodic experiences.

PubMed

Malinowski, Josie E; Horton, Caroline L

2014-08-01

The present study aimed to explore autobiographical memories (long-lasting memories about the self) and episodic memories (memories about discrete episodes or events) within dream content. We adapted earlier episodic memory study paradigms and reinvestigated the incorporation of episodic memory sources into dreams, operationalizing episodic memory as featuring autonoetic consciousness, which is the feeling of truly re-experiencing or reliving a past event. Participants (n = 32) recorded daily diaries and dream diaries, and reported on wake-dream relations for 2 weeks. Using a new scale, dreams were rated for their episodic richness, which categorized memory sources of dreams as being truly episodic (featuring autonoetic consciousness), autobiographical (containing segregated features of experiences that pertained to waking life) or otherwise. Only one dream (0.5%) was found to contain an episodic memory. However, the majority of dreams (>80%) were found to contain low to moderate incorporations of autobiographical memory features. These findings demonstrate the inactivity of intact episodic memories, and emphasize the activity of autobiographical memory and processing within dreams. Taken together, this suggests that memories for personal experiences are experienced fragmentarily and selectively during dreaming, perhaps in order to assimilate these memories into the autobiographical memory schema. © 2014 European Sleep Research Society.

Episodic Memory and Episodic Future Thinking Impairments in High-Functioning Autism Spectrum Disorder: An Underlying Difficulty With Scene Construction or Self-Projection?

PubMed Central

2013-01-01

Objective: There appears to be a common network of brain regions that underlie the ability to recall past personal experiences (episodic memory) and the ability to imagine possible future personal experiences (episodic future thinking). At the cognitive level, these abilities are thought to rely on “scene construction” (the ability to bind together multimodal elements of a scene in mind—dependent on hippocampal functioning) and temporal “self-projection” (the ability to mentally project oneself through time—dependent on prefrontal cortex functioning). Although autism spectrum disorder (ASD) is characterized by diminished episodic memory, it is unclear whether episodic future thinking is correspondingly impaired. Moreover, the underlying basis of such impairments (difficulties with scene construction, self-projection, or both) is yet to be established. The current study therefore aimed to elucidate these issues. Method: Twenty-seven intellectually high-functioning adults with ASD and 29 age- and IQ-matched neurotypical comparison adults were asked to describe (a) imagined atemporal, non-self-relevant fictitious scenes (assessing scene construction), (b) imagined plausible self-relevant future episodes (assessing episodic future thinking), and (c) recalled personally experienced past episodes (assessing episodic memory). Tests of narrative ability and theory of mind were also completed. Results: Performances of participants with ASD were significantly and equally diminished in each condition and, crucially, this diminution was independent of general narrative ability. Conclusions: Given that participants with ASD were impaired in the fictitious scene condition, which does not involve self-projection, we suggest the underlying difficulty with episodic memory/future thinking is one of scene construction. PMID:24015827

Episodic memory and episodic future thinking impairments in high-functioning autism spectrum disorder: an underlying difficulty with scene construction or self-projection?

PubMed

Lind, Sophie E; Williams, David M; Bowler, Dermot M; Peel, Anna

2014-01-01

There appears to be a common network of brain regions that underlie the ability to recall past personal experiences (episodic memory) and the ability to imagine possible future personal experiences (episodic future thinking). At the cognitive level, these abilities are thought to rely on "scene construction" (the ability to bind together multimodal elements of a scene in mind--dependent on hippocampal functioning) and temporal "self-projection" (the ability to mentally project oneself through time--dependent on prefrontal cortex functioning). Although autism spectrum disorder (ASD) is characterized by diminished episodic memory, it is unclear whether episodic future thinking is correspondingly impaired. Moreover, the underlying basis of such impairments (difficulties with scene construction, self-projection, or both) is yet to be established. The current study therefore aimed to elucidate these issues. Twenty-seven intellectually high-functioning adults with ASD and 29 age- and IQ-matched neurotypical comparison adults were asked to describe (a) imagined atemporal, non-self-relevant fictitious scenes (assessing scene construction), (b) imagined plausible self-relevant future episodes (assessing episodic future thinking), and (c) recalled personally experienced past episodes (assessing episodic memory). Tests of narrative ability and theory of mind were also completed. Performances of participants with ASD were significantly and equally diminished in each condition and, crucially, this diminution was independent of general narrative ability. Given that participants with ASD were impaired in the fictitious scene condition, which does not involve self-projection, we suggest the underlying difficulty with episodic memory/future thinking is one of scene construction.

The role of episodic memory in controlled evaluative judgments about attitudes: an event-related potential study.

PubMed

Johnson, Ray; Simon, Elizabeth J; Henkell, Heather; Zhu, John

2011-04-01

Event-related potentials (ERPs) are unique in their ability to provide information about the timing of activity in the neural networks that perform complex cognitive processes. Given the dearth of extant data from normal controls on the question of whether attitude representations are stored in episodic or semantic memory, the goal here was to study the nature of the memory representations used during conscious attitude evaluations. Thus, we recorded ERPs while participants performed three tasks: attitude evaluations (i.e., agree/disagree), autobiographical cued recall (i.e., You/Not You) and semantic evaluations (i.e., active/inactive). The key finding was that the parietal episodic memory (EM) effect, a well-established correlate of episodic recollection, was elicited by both attitude evaluations and autobiographical retrievals. By contrast, semantic evaluations of the same attitude items elicited less parietal activity, like that elicited by Not You cues, which only access semantic memory. In accord with hemodynamic results, attitude evaluations and autobiographical retrievals also produced overlapping patterns of slow potential (SP) activity from 500 to 900ms preceding the response over left and right inferior frontal, anterior medial frontal and occipital brain areas. Significantly different patterns of SP activity were elicited in these locations for semantic evaluations and Not You cues. Taken together, the results indicate that attitude representations are stored in episodic memory. Retrieval timing varied as a function of task, with earlier retrievals in both evaluation conditions relative to those in the autobiographical condition. The differential roles and timing of memory retrieval in evaluative judgment and memory retrieval tasks are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Neuropsychological and SPECT scan findings during and after transient global amnesia: evidence for the differential impairment of remote episodic memory.

PubMed

Evans, J; Wilson, B; Wraight, E P; Hodges, J R

1993-11-01

A patient had neuropsychological testing during, and at two days and seven weeks after a transient global amnesia (TGA) attack. During the attack she exhibited a characteristically profound anterograde amnesia but a limited remote memory loss; the most striking impairment was a deficit in personal episodic memory revealed by her performance on the Autobiographical Memory Interview. Personal and general semantic information was less impaired although there were indications of a temporal gradient in the impairment. When tested after the attack, she demonstrated normal anterograde and retrograde memory. A SPECT scan performed during TGA showed a focal reduction in cerebral perfusion in the postero-medial temporal lobes bilaterally which had resolved after seven weeks.

Altered Episodic Memory in Introverted Young Adults Carrying the BDNFMet Allele

PubMed Central

Bombardier, Andreanne; Beauchemin, Maude; Gosselin, Nadia; Poirier, Judes; De Beaumont, Louis

2016-01-01

While most studies have been interested in the distinct, predisposing roles of the common BDNF Val66Met variant and extraversion personality traits on episodic memory, very few studies have looked at the synergistic effects of genetic and personality factors to account for cognitive variance. This is surprising considering recent reports challenging the long-held belief that the BDNFMet variant negatively impacts cognitive function. A total of 75 young healthy adults (26 of them carried at least one copy of the BDNFMet allele) took part in this study consisting of genetic profiling from saliva, personality assessment using the Revised NEO Personality Inventory (NEO PI-R) and a short battery of neuropsychological tests. An ANOVA revealed that BDNFMet carriers were significantly less extraverted than BDNFVal carriers (F1,73 = 9.54; p < 0.01; ηp2 = 0.126). Moreover, extraversion was found to significantly moderate the relationship between the BDNF genotype and episodic memory performance (p = 0.03). Subsequent correlational analyses yielded a strong and significant correlation (r = 0.542; p < 0.005) between introversion and delayed episodic memory specific to BDNFMet individuals. The present study suggests that introversion and the BDNFMet variant synergistically interact to reduce episodic memory performance in healthy, young adults. These findings reaffirm that a more accurate explanation of cognitive variance can be achieved by looking at the synergistic effects of genotype and phenotype factors. PMID:27845759

Altered Episodic Memory in Introverted Young Adults Carrying the BDNFMet Allele.

PubMed

Bombardier, Andreanne; Beauchemin, Maude; Gosselin, Nadia; Poirier, Judes; De Beaumont, Louis

2016-11-12

While most studies have been interested in the distinct, predisposing roles of the common BDNF Val66Met variant and extraversion personality traits on episodic memory, very few studies have looked at the synergistic effects of genetic and personality factors to account for cognitive variance. This is surprising considering recent reports challenging the long-held belief that the BDNF Met variant negatively impacts cognitive function. A total of 75 young healthy adults (26 of them carried at least one copy of the BDNF Met allele) took part in this study consisting of genetic profiling from saliva, personality assessment using the Revised NEO Personality Inventory (NEO PI-R) and a short battery of neuropsychological tests. An ANOVA revealed that BDNF Met carriers were significantly less extraverted than BDNF Val carriers ( F 1,73 = 9.54; p < 0.01; η p ² = 0.126). Moreover, extraversion was found to significantly moderate the relationship between the BDNF genotype and episodic memory performance ( p = 0.03). Subsequent correlational analyses yielded a strong and significant correlation ( r = 0.542; p < 0.005) between introversion and delayed episodic memory specific to BDNF Met individuals. The present study suggests that introversion and the BDNF Met variant synergistically interact to reduce episodic memory performance in healthy, young adults. These findings reaffirm that a more accurate explanation of cognitive variance can be achieved by looking at the synergistic effects of genotype and phenotype factors.

Episodic memories.

PubMed

Conway, Martin A

2009-09-01

An account of episodic memories is developed that focuses on the types of knowledge they represent, their properties, and the functions they might serve. It is proposed that episodic memories consist of episodic elements, summary records of experience often in the form of visual images, associated to a conceptual frame that provides a conceptual context. Episodic memories are embedded in a more complex conceptual system in which they can become the basis of autobiographical memories. However, the function of episodic memories is to keep a record of progress with short-term goals and access to most episodic memories is lost soon after their formation. Finally, it is suggested that developmentally episodic memories form the basis of the conceptual system and it is from sets of episodic memories that early non-verbal conceptual knowledge is abstracted.

Subjective memory complaint only relates to verbal episodic memory performance in mild cognitive impairment

PubMed Central

Gifford, Katherine A.; Liu, Dandan; Damon, Stephen M.; Chapman, William G.; Romano, Raymond R.; Samuels, Lauren R.; Lu, Zengqi; Jefferson, Angela L.

2015-01-01

Background A cognitive concern from the patient, informant, or clinician is required for the diagnosis of mild cognitive impairment (MCI); however, the cognitive and neuroanatomical correlates of complaint are poorly understood. Objective We assessed how self-complaint relates to cognitive and neuroimaging measures in older adults with MCI. Method MCI participants were drawn from the Alzheimer’s Disease Neuroimaging Initiative and dichotomized into two groups based on the presence of self-reported memory complaint (no complaint n=191, 77±7 years; complaint n=206, 73±8 years). Cognitive outcomes included episodic memory, executive functioning, information processing speed, and language. Imaging outcomes included regional lobar volumes (frontal, parietal, temporal, cingulate) and specific medial temporal lobe structures (hippocampal volume, entorhinal cortex thickness, parahippocampal gyrus thickness). Results Linear regressions, adjusting for age, gender, race, education, Mini-Mental State Examination score, mood, and apolipoprotein E-4 status, found that cognitive complaint related to immediate (β=−1.07, p<0.001) and delayed episodic memory performances assessed on a serial list learning task (β=−1.06, p=0.001) but no other cognitive measures or neuroimaging markers. Conclusions Self-reported memory concern was unrelated to structural neuroimaging markers of atrophy and measures of information processing speed, executive functioning, or language. In contrast, subjective memory complaint related to objective verbal episodic learning performance. Future research is warranted to better understand the relation between cognitive complaint and surrogate markers of abnormal brain aging, including Alzheimer’s disease, across the cognitive aging spectrum. PMID:25281602

Creativity and Memory: Effects of an Episodic Specificity Induction on Divergent Thinking

PubMed Central

Madore, Kevin P.; Addis, Donna Rose; Schacter, Daniel L.

2015-01-01

After receiving an episodic specificity induction - brief training in recollecting details of a recent event - people produce more episodic details when imagining future events and solving means-end problems than after receiving a control induction not focused on episodic retrieval. Here we show for the first time that an episodic specificity induction also enhances divergent creative thinking. In Experiment 1, participants exhibited a selective boost on a divergent thinking task that involves generating unusual uses of common objects after a specificity induction compared with a control induction; by contrast, performance was similar on an object association task thought to involve little divergent thinking. In Experiment 2, we replicated the specificity induction effect on divergent thinking using a different control induction, and also found that participants performed similarly on a convergent thinking task following both inductions. These experiments provide novel evidence that episodic memory is involved in divergent creative thinking. PMID:26205963

Episodic Memory Retrieval Benefits from a Less Modular Brain Network Organization

PubMed Central

2017-01-01

Most complex cognitive tasks require the coordinated interplay of multiple brain networks, but the act of retrieving an episodic memory may place especially heavy demands for communication between the frontoparietal control network (FPCN) and the default mode network (DMN), two networks that do not strongly interact with one another in many task contexts. We applied graph theoretical analysis to task-related fMRI functional connectivity data from 20 human participants and found that global brain modularity—a measure of network segregation—is markedly reduced during episodic memory retrieval relative to closely matched analogical reasoning and visuospatial perception tasks. Individual differences in modularity were correlated with memory task performance, such that lower modularity levels were associated with a lower false alarm rate. Moreover, the FPCN and DMN showed significantly elevated coupling with each other during the memory task, which correlated with the global reduction in brain modularity. Both networks also strengthened their functional connectivity with the hippocampus during the memory task. Together, these results provide a novel demonstration that reduced modularity is conducive to effective episodic retrieval, which requires close collaboration between goal-directed control processes supported by the FPCN and internally oriented self-referential processing supported by the DMN. SIGNIFICANCE STATEMENT Modularity, an index of the degree to which nodes of a complex system are organized into discrete communities, has emerged as an important construct in the characterization of brain connectivity dynamics. We provide novel evidence that the modularity of the human brain is reduced when individuals engage in episodic memory retrieval, relative to other cognitive tasks, and that this state of lower modularity is associated with improved memory performance. We propose a neural systems mechanism for this finding where the nodes of the frontoparietal control network and default mode network strengthen their interaction with one another during episodic retrieval. Such across-network communication likely facilitates effective access to internally generated representations of past event knowledge. PMID:28242796

Episodic Memory Retrieval Benefits from a Less Modular Brain Network Organization.

PubMed

Westphal, Andrew J; Wang, Siliang; Rissman, Jesse

2017-03-29

Most complex cognitive tasks require the coordinated interplay of multiple brain networks, but the act of retrieving an episodic memory may place especially heavy demands for communication between the frontoparietal control network (FPCN) and the default mode network (DMN), two networks that do not strongly interact with one another in many task contexts. We applied graph theoretical analysis to task-related fMRI functional connectivity data from 20 human participants and found that global brain modularity-a measure of network segregation-is markedly reduced during episodic memory retrieval relative to closely matched analogical reasoning and visuospatial perception tasks. Individual differences in modularity were correlated with memory task performance, such that lower modularity levels were associated with a lower false alarm rate. Moreover, the FPCN and DMN showed significantly elevated coupling with each other during the memory task, which correlated with the global reduction in brain modularity. Both networks also strengthened their functional connectivity with the hippocampus during the memory task. Together, these results provide a novel demonstration that reduced modularity is conducive to effective episodic retrieval, which requires close collaboration between goal-directed control processes supported by the FPCN and internally oriented self-referential processing supported by the DMN. SIGNIFICANCE STATEMENT Modularity, an index of the degree to which nodes of a complex system are organized into discrete communities, has emerged as an important construct in the characterization of brain connectivity dynamics. We provide novel evidence that the modularity of the human brain is reduced when individuals engage in episodic memory retrieval, relative to other cognitive tasks, and that this state of lower modularity is associated with improved memory performance. We propose a neural systems mechanism for this finding where the nodes of the frontoparietal control network and default mode network strengthen their interaction with one another during episodic retrieval. Such across-network communication likely facilitates effective access to internally generated representations of past event knowledge. Copyright © 2017 the authors 0270-6474/17/373523-09$15.00/0.

Functional Magnetic Resonance Imaging Correlates of First-Episode Psychoses during Attentional and Memory Task Performance.

PubMed

Del Casale, Antonio; Kotzalidis, Georgios D; Rapinesi, Chiara; Sorice, Serena; Girardi, Nicoletta; Ferracuti, Stefano; Girardi, Paolo

2016-01-01

The nature of the alteration of the response to cognitive tasks in first-episode psychosis (FEP) still awaits clarification. We used activation likelihood estimation, an increasingly used method in evaluating normal and pathological brain function, to identify activation changes in functional magnetic resonance imaging (fMRI) studies of FEP during attentional and memory tasks. We included 11 peer-reviewed fMRI studies assessing FEP patients versus healthy controls (HCs) during performance of attentional and memory tasks. Our database comprised 290 patients with FEP, matched with 316 HCs. Between-group analyses showed that HCs, compared to FEP patients, exhibited hyperactivation of the right middle frontal gyrus (Brodmann area, BA, 9), right inferior parietal lobule (BA 40), and right insula (BA 13) during attentional task performances and hyperactivation of the left insula (BA 13) during memory task performances. Right frontal, parietal, and insular dysfunction during attentional task performance and left insular dysfunction during memory task performance are significant neural functional FEP correlates. © 2016 S. Karger AG, Basel.

The relation of hippocampal subfield volumes to verbal episodic memory measured by the California Verbal Learning Test II in healthy adults.

PubMed

Aslaksen, Per M; Bystad, Martin K; Ørbo, Marte C; Vangberg, Torgil R

2018-06-08

Total hippocampal volume has previously been shown to correlate with performance on tests for verbal episodic memory. However, there are sparse evidence on how hippocampal subfield volumes are related to verbal episodic memory in healthy adults. The present study investigated the association between volumes of separate hippocampal subfields and verbal episodic memory performance in healthy volunteers. Forty-seven participants (31 females) between 20 to 71 years age underwent testing with the California Verbal Learning Test II (CVLT II), and the Wechsler Abbreviated Scale of Intelligence (WASI) to obtain an estimate of cognitive functioning. T1-weighted MR images were obtained after cognitive testing, and volumetric estimates adjusted for age and estimated total intracranial volume were calculated in the FreeSurfer 6.0 software suite for cerebral -and hippocampal structures. The sample performed within the statistical normal range on both CVLT II and WASI. Significant correlations adjusted for multiple testing were found between CVLT II subtests of total learning, free immediate recall and free delayed recall and volumes of the left Cornu Ammonis (CA) 1-4 subfields. There were no significant correlations between right hippocampal subfields and CVLT II performance, and no significant correlation between WASI results and hippocampal subfields. The present results suggest that better verbal episodic memory measured by the CVLT II is associated with relative larger volumes of specific left CA hippocampal subfields in healthy adults. Due to the small sample size and large age-span of the participants, the present findings are preliminary and should be confirmed in larger samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Cued recall from image and sentence memory: a shift from episodic to identical elements representation.

PubMed

Rickard, Timothy C; Bajic, Daniel

2006-07-01

The applicability of the identical elements (IE) model of arithmetic fact retrieval (T. C. Rickard, A. F. Healy, & L. E. Bourne, 1994) to cued recall from episodic (image and sentence) memory was explored in 3 transfer experiments. In agreement with results from arithmetic, speedup following even minimal practice recalling a missing word from an episodically bound word triplet did not transfer positively to other cued recall items involving the same triplet. The shape of the learning curve further supported a shift from episode-based to IE-based recall, extending some models of skill learning to cued recall practice. In contrast with previous findings, these results indicate that a form of representation that is independent of the original episodic memory underlies cued-recall performance following minimal practice. Copyright 2006 APA, all rights reserved.

Genotype patterns at PICALM, CR1, BIN1, CLU, and APOE genes are associated with episodic memory

PubMed Central

Barral, S.; Bird, T.; Goate, A.; Farlow, M.R.; Diaz-Arrastia, R.; Bennett, D.A.; Graff-Radford, N.; Boeve, B.F.; Sweet, R.A.; Stern, Y.; Wilson, R.S.; Foroud, T.; Ott, J.; Green, Robert; Kowall, Neil; Farrer, Lindsay; Williamson, Jennifer; Santana, Vincent; Schmechel, Donald; Gaskel, Peter; Ghetti, Bernardino; Farlow, Martin R.; Faber, Kelley; Prentice, Heather; Horner, Kelly; Growdon, John H.; Blacker, Deborah; Tanzi, Rudolph E.; Hyman, Bradley T.; Boeve, Bradley; Kuntz, Karen; Norgaard, Lindsay; Larson, Nathan; Kistler, Dana; Parfitt, Francine; Haddow, Jenny; Silverman, Jeremy; Beeri, Michal Schnaider; Sano, Mary; Wang, Joy; Lally, Rachel; Johnson, Nancy; Mesulam, Marcel; Weintraub, Sandra; Bigio, Eileen; Kaye, Jeffery; Kramer, Patricia; Payne-Murphy, Jessica; Bennett, David; Jacobs, Holli; Chang, Jeen-Soo; Arends, Danielle; Harrell, Lindy; Bartzokis, George; Cummings, Jeffery; Lu, Po H.; Toland, Usha; Smith, Charles; Brickhouse, Alise; Trojanowski, John; Van Deerlin, Vivianna; McCarty Wood, Elisabeth; DeKosky, Steven; Sweet, Robert; Weamer, Elise; Chui, Helena; Varpetian, Arousiak; Diaz-Arrastia, Ramon; Rosenberg, Roger; Davis, Barbara; Bird, Thomas; Schellenberg, Gerard D.; Raskind, Murray; Rumbaugh, Malia; Nickel, Kate; Goate, Alison; Morris, John; Norton, Joanne; Levitch, Denise; Grant, Betsy; Coats, Mary; Levey, Allen; Rosen, Ami; Anosike, Ezinna

2012-01-01

Objective: Several genome-wide association studies (GWAS) have associated variants in late-onset Alzheimer disease (LOAD) susceptibility genes; however, these single nucleotide polymorphisms (SNPs) have very modest effects, suggesting that single SNP approaches may be inadequate to identify genetic risks. An alternative approach is the use of multilocus genotype patterns (MLGPs) that combine SNPs at different susceptibility genes. Methods: Using data from 1,365 subjects in the National Institute on Aging Late-Onset Alzheimer's Disease Family Study, we conducted a family-based association study in which we tabulated MLGPs for SNPs at CR1, BIN1, CLU, PICALM, and APOE. We used generalized estimating equations to model episodic memory as the dependent endophenotype of LOAD and the MLGPs as predictors while adjusting for sex, age, and education. Results: Several genotype patterns influenced episodic memory performance. A pattern that included PICALM and CLU was the strongest genotypic profile for lower memory performance (β = −0.32, SE = 0.19, p = 0.021). The effect was stronger after addition of APOE (p = 0.016). Two additional patterns involving PICALM, CR1, and APOE and another pattern involving PICALM, BIN1, and APOE were also associated with significantly poorer memory performance (β = −0.44, SE = 0.09, p = 0.009 and β = −0.29, SE = 0.07, p = 0.012) even after exclusion of patients with LOAD. We also identified genotype pattern involving variants in PICALM, CLU, and APOE as a predictor of better memory performance (β = 0.26, SE = 0.10, p = 0.010). Conclusions: MLGPs provide an alternative analytical approach to predict an individual's genetic risk for episodic memory performance, a surrogate indicator of LOAD. Identifying genotypic patterns contributing to the decline of an individual's cognitive performance may be a critical step along the road to preclinical detection of Alzheimer disease. PMID:22539578

Non-Interfering Effects of Active Post-Encoding Tasks on Episodic Memory Consolidation in Humans

PubMed Central

Varma, Samarth; Takashima, Atsuko; Krewinkel, Sander; van Kooten, Maaike; Fu, Lily; Medendorp, W. Pieter; Kessels, Roy P. C.; Daselaar, Sander M.

2017-01-01

So far, studies that investigated interference effects of post-learning processes on episodic memory consolidation in humans have used tasks involving only complex and meaningful information. Such tasks require reallocation of general or encoding-specific resources away from consolidation-relevant activities. The possibility that interference can be elicited using a task that heavily taxes our limited brain resources, but has low semantic and hippocampal related long-term memory processing demands, has never been tested. We address this question by investigating whether consolidation could persist in parallel with an active, encoding-irrelevant, minimally semantic task, regardless of its high resource demands for cognitive processing. We distinguish the impact of such a task on consolidation based on whether it engages resources that are: (1) general/executive, or (2) specific/overlapping with the encoding modality. Our experiments compared subsequent memory performance across two post-encoding consolidation periods: quiet wakeful rest and a cognitively demanding n-Back task. Across six different experiments (total N = 176), we carefully manipulated the design of the n-Back task to target general or specific resources engaged in the ongoing consolidation process. In contrast to previous studies that employed interference tasks involving conceptual stimuli and complex processing demands, we did not find any differences between n-Back and rest conditions on memory performance at delayed test, using both recall and recognition tests. Our results indicate that: (1) quiet, wakeful rest is not a necessary prerequisite for episodic memory consolidation; and (2) post-encoding cognitive engagement does not interfere with memory consolidation when task-performance has minimal semantic and hippocampally-based episodic memory processing demands. We discuss our findings with reference to resource and reactivation-led interference theories. PMID:28424596

Non-Interfering Effects of Active Post-Encoding Tasks on Episodic Memory Consolidation in Humans.

PubMed

Varma, Samarth; Takashima, Atsuko; Krewinkel, Sander; van Kooten, Maaike; Fu, Lily; Medendorp, W Pieter; Kessels, Roy P C; Daselaar, Sander M

2017-01-01

So far, studies that investigated interference effects of post-learning processes on episodic memory consolidation in humans have used tasks involving only complex and meaningful information. Such tasks require reallocation of general or encoding-specific resources away from consolidation-relevant activities. The possibility that interference can be elicited using a task that heavily taxes our limited brain resources, but has low semantic and hippocampal related long-term memory processing demands, has never been tested. We address this question by investigating whether consolidation could persist in parallel with an active, encoding-irrelevant, minimally semantic task, regardless of its high resource demands for cognitive processing. We distinguish the impact of such a task on consolidation based on whether it engages resources that are: (1) general/executive, or (2) specific/overlapping with the encoding modality. Our experiments compared subsequent memory performance across two post-encoding consolidation periods: quiet wakeful rest and a cognitively demanding n-Back task. Across six different experiments (total N = 176), we carefully manipulated the design of the n-Back task to target general or specific resources engaged in the ongoing consolidation process. In contrast to previous studies that employed interference tasks involving conceptual stimuli and complex processing demands, we did not find any differences between n-Back and rest conditions on memory performance at delayed test, using both recall and recognition tests. Our results indicate that: (1) quiet, wakeful rest is not a necessary prerequisite for episodic memory consolidation; and (2) post-encoding cognitive engagement does not interfere with memory consolidation when task-performance has minimal semantic and hippocampally-based episodic memory processing demands. We discuss our findings with reference to resource and reactivation-led interference theories.

Autobiographical memory and patterns of brain atrophy in frontotemporal lobar degeneration.

PubMed

McKinnon, Margaret C; Nica, Elena I; Sengdy, Pheth; Kovacevic, Natasa; Moscovitch, Morris; Freedman, Morris; Miller, Bruce L; Black, Sandra E; Levine, Brian

2008-10-01

Autobiographical memory paradigms have been increasingly used to study the behavioral and neuroanatomical correlates of human remote memory. Although there are numerous functional neuroimaging studies on this topic, relatively few studies of patient samples exist, with heterogeneity of results owing to methodological variability. In this study, fronto-temporal lobar degeneration (FTLD), a form of dementia affecting regions crucial to autobiographical memory, was used as a model of autobiographical memory loss. We emphasized the separation of episodic (recollection of specific event, perceptual, and mental state information) from semantic (factual information unspecific in time and place) autobiographical memory, derived from a reliable method for scoring transcribed autobiographical protocols, the Autobiographical Interview [Levine, B., Svoboda, E., Hay, J., Winocur, G., & Moscovitch, M. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689, 2002]. Patients with the fronto-temporal dementia (FTD) and mixed fronto-temporal and semantic dementia (FTD/SD) variants of FTLD were impaired at reconstructing episodically rich autobiographical memories across the lifespan, with FTD/SD patients generating an excess of generic semantic autobiographical information. Patients with progressive nonfluent aphasia were mildly impaired for episodic autobiographical memory, but this impairment was eliminated with the provision of structured cueing, likely reflecting relatively intact medial-temporal lobe function, whereas the same cueing failed to bolster the FTD and FTD/SD patients' performance relative to that of matched comparison subjects. The pattern of episodic, but not semantic, autobiographical impairment was enhanced with disease progression on 1- to 2-year follow-up testing in a subset of patients, supplementing the cross-sectional evidence for specificity of episodic autobiographical impairment with longitudinal data. This behavioral pattern covaried with volume loss in a distributed left-lateralized posterior network centered on the temporal lobe, consistent with evidence from other patient and functional neuroimaging studies of autobiographical memory. Frontal lobe volumes, however, did not significantly contribute to this network, suggesting that frontal contributions to autobiographical episodic memory may be more complex than previously appreciated.

Evidence that hippocampal-parahippocampal dysfunction is related to genetic risk for schizophrenia.

PubMed

Di Giorgio, A; Gelao, B; Caforio, G; Romano, R; Andriola, I; D'Ambrosio, E; Papazacharias, A; Elifani, F; Bianco, L Lo; Taurisano, P; Fazio, L; Popolizio, T; Blasi, G; Bertolino, A

2013-08-01

Abnormalities in hippocampal-parahippocampal (H-PH) function are prominent features of schizophrenia and have been associated with deficits in episodic memory. However, it remains unclear whether these abnormalities represent a phenotype related to genetic risk for schizophrenia or whether they are related to disease state. We investigated H-PH-mediated behavior and physiology, using blood oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI), during episodic memory in a sample of patients with schizophrenia, clinically unaffected siblings and healthy subjects. Patients with schizophrenia and unaffected siblings displayed abnormalities in episodic memory performance. During an fMRI memory encoding task, both patients and siblings demonstrated a similar pattern of reduced H-PH engagement compared with healthy subjects. Our findings suggest that the pathophysiological mechanism underlying the inability of patients with schizophrenia to properly engage the H-PH during episodic memory is related to genetic risk for the disorder. Therefore, H-PH dysfunction can be assumed as a schizophrenia susceptibility-related phenotype.

Subliminal encoding and flexible retrieval of objects in scenes.

PubMed

Wuethrich, Sergej; Hannula, Deborah E; Mast, Fred W; Henke, Katharina

2018-04-27

Our episodic memory stores what happened when and where in life. Episodic memory requires the rapid formation and flexible retrieval of where things are located in space. Consciousness of the encoding scene is considered crucial for episodic memory formation. Here, we question the necessity of consciousness and hypothesize that humans can form unconscious episodic memories. Participants were presented with subliminal scenes, i.e., scenes invisible to the conscious mind. The scenes displayed objects at certain locations for participants to form unconscious object-in-space memories. Later, the same scenes were presented supraliminally, i.e., visibly, for retrieval testing. Scenes were presented absent the objects and rotated by 90°-270° in perspective to assess the representational flexibility of unconsciously formed memories. During the test phase, participants performed a forced-choice task that required them to place an object in one of two highlighted scene locations and their eye movements were recorded. Evaluation of the eye tracking data revealed that participants remembered object locations unconsciously, irrespective of changes in viewing perspective. This effect of gaze was related to correct placements of objects in scenes, and an intuitive decision style was necessary for unconscious memories to influence intentional behavior to a significant degree. We conclude that conscious perception is not mandatory for spatial episodic memory formation. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

Test-retest reliability and validity of the Sniffin' TOM odor memory test.

PubMed

Croy, Ilona; Zehner, Cora; Larsson, Maria; Zucco, Gesualdo M; Hummel, Thomas

2015-03-01

Few attempts have been made to develop an olfactory test that captures episodic retention of olfactory information. Assessment of episodic odor memory is of particular interest in aging and in the cognitively impaired as both episodic memory deficits and olfactory loss have been targeted as reliable hallmarks of cognitive decline and impending dementia. Here, 96 healthy participants (18-92 years) and an additional 19 older people with mild cognitive impairment were tested (73-82 years). Participants were presented with 8 common odors with intentional encoding instructions that were followed by a yes-no recognition test. After recognition completion, participants were asked to identify all odors by means of free or cued identification. A retest of the odor memory test (Sniffin' TOM = test of odor memory) took place 17 days later. The results revealed satisfactory test-retest reliability (0.70) of odor recognition memory. Both recognition and identification performance were negatively affected by age and more pronounced among the cognitively impaired. In conclusion, the present work presents a reliable, valid, and simple test of episodic odor recognition memory that may be used in clinical groups where both episodic memory deficits and olfactory loss are prevalent preclinically such as Alzheimer's disease. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Not only … but also: REM sleep creates and NREM Stage 2 instantiates landmark junctions in cortical memory networks.

PubMed

Llewellyn, Sue; Hobson, J Allan

2015-07-01

This article argues both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep contribute to overnight episodic memory processes but their roles differ. Episodic memory may have evolved from memory for spatial navigation in animals and humans. Equally, mnemonic navigation in world and mental space may rely on fundamentally equivalent processes. Consequently, the basic spatial network characteristics of pathways which meet at omnidirectional nodes or junctions may be conserved in episodic brain networks. A pathway is formally identified with the unidirectional, sequential phases of an episodic memory. In contrast, the function of omnidirectional junctions is not well understood. In evolutionary terms, both animals and early humans undertook tours to a series of landmark junctions, to take advantage of resources (food, water and shelter), whilst trying to avoid predators. Such tours required memory for emotionally significant landmark resource-place-danger associations and the spatial relationships amongst these landmarks. In consequence, these tours may have driven the evolution of both spatial and episodic memory. The environment is dynamic. Resource-place associations are liable to shift and new resource-rich landmarks may be discovered, these changes may require re-wiring in neural networks. To realise these changes, REM may perform an associative, emotional encoding function between memory networks, engendering an omnidirectional landmark junction which is instantiated in the cortex during NREM Stage 2. In sum, REM may preplay associated elements of past episodes (rather than replay individual episodes), to engender an unconscious representation which can be used by the animal on approach to a landmark junction in wake. Copyright © 2015 Elsevier Inc. All rights reserved.

A critical evaluation of monkey models of amnesia and dementia.

PubMed

Ridley, R M; Baker, H F

1991-01-01

In this review we consider various models of amnesia and dementia in monkeys and examine the validity of such models. In Section 2 we describe the various types of memory tests (tasks) available for use with monkeys and discuss the extent to which these tasks assess different facets of memory according to present theories of human memory. We argue that the rules which govern correct task performance are best regarded as a form of semantic rather than procedural memory, and that when information about stimulus attributes or reward associations is stored long-term then that knowledge is semantic. The demonstration of episodic memory in monkeys is problematic and the term recognition memory has been used too loosely. In particular, it is difficult to dissociate episodic memory for stimulus events from the use of semantic memory for the rule of the task, since dysfunction of either can produce impairment on performance of the same task. Tasks can also be divided into those which assess memory for stimulus-reward associations (evaluative memory) and those which tax stimulus-response associations including spatial and conditional responding (non-evaluative memory). This dissociation cuts across the distinction between semantic and episodic memory. In Section 3 we examine the usefulness of the classification of tasks described in Section 2 in clarifying our understanding of the contribution of the temporal lobes and the cholinergic system to memory. We conclude that evaluative and non-evaluative memory are mediated by separate parallel systems involving the amygdala and hippocampus, respectively.

The evolution of episodic memory

PubMed Central

Allen, Timothy A.; Fortin, Norbert J.

2013-01-01

One prominent view holds that episodic memory emerged recently in humans and lacks a “(neo)Darwinian evolution” [Tulving E (2002) Annu Rev Psychol 53:1–25]. Here, we review evidence supporting the alternative perspective that episodic memory has a long evolutionary history. We show that fundamental features of episodic memory capacity are present in mammals and birds and that the major brain regions responsible for episodic memory in humans have anatomical and functional homologs in other species. We propose that episodic memory capacity depends on a fundamental neural circuit that is similar across mammalian and avian species, suggesting that protoepisodic memory systems exist across amniotes and, possibly, all vertebrates. The implication is that episodic memory in diverse species may primarily be due to a shared underlying neural ancestry, rather than the result of evolutionary convergence. We also discuss potential advantages that episodic memory may offer, as well as species-specific divergences that have developed on top of the fundamental episodic memory architecture. We conclude by identifying possible time points for the emergence of episodic memory in evolution, to help guide further research in this area. PMID:23754432

Developmental differences in episodic memory across school ages: evidence from enacted events performed by self and others.

PubMed

Badinlou, Farzaneh; Kormi-Nouri, Reza; Mousavi Nasab, S M Hossein; Knopf, Monika

2017-01-01

The aim of this study was to examine action memory as a form of episodic memory among school-aged subjects. Most research on action memory has focused on memory changes in adult populations. This study explored the action memory of children over time. A total of 410 school-aged child participants, comprising 201 girls and 208 boys in four age groups (8, 10, 12, and 14), were included in this study. We studied two forms of action encoding, subject-performed tasks (SPTs) and experimenter-performed tasks (EPTs), which were compared with one verbal encoding task as a control condition. At retrieval, we used three memory tests (free recall, cued recall, and recognition). We observed significant differences in memory performance in children aged 8-14 years with respect to free recall and cued recall but not recognition. The largest memory enhancement was observed for the SPTs in the 8-14-year-old participants under all test conditions. Participants performed equally well on the free recall of SPTs and EPTs, whereas they displayed better performances on the cued recall and recognition of SPTs compared to EPTs. The strategic nature of SPTs and the distinction between item-specific information and relational information are discussed.

Working memory deficits in boys with attention deficit/hyperactivity disorder (ADHD): An examination of orthographic coding and episodic buffer processes.

PubMed

Alderson, R Matt; Kasper, Lisa J; Patros, Connor H G; Hudec, Kristen L; Tarle, Stephanie J; Lea, Sarah E

2015-01-01

The episodic buffer component of working memory was examined in children with attention deficit/hyperactivity disorder (ADHD) and typically developing peers (TD). Thirty-two children (ADHD = 16, TD = 16) completed three versions of a phonological working memory task that varied with regard to stimulus presentation modality (auditory, visual, or dual auditory and visual), as well as a visuospatial task. Children with ADHD experienced the largest magnitude working memory deficits when phonological stimuli were presented via a unimodal, auditory format. Their performance improved during visual and dual modality conditions but remained significantly below the performance of children in the TD group. In contrast, the TD group did not exhibit performance differences between the auditory- and visual-phonological conditions but recalled significantly more stimuli during the dual-phonological condition. Furthermore, relative to TD children, children with ADHD recalled disproportionately fewer phonological stimuli as set sizes increased, regardless of presentation modality. Finally, an examination of working memory components indicated that the largest magnitude between-group difference was associated with the central executive. Collectively, these findings suggest that ADHD-related working memory deficits reflect a combination of impaired central executive and phonological storage/rehearsal processes, as well as an impaired ability to benefit from bound multimodal information processed by the episodic buffer.

Cholinergic modulation of cognitive processing: insights drawn from computational models

PubMed Central

Newman, Ehren L.; Gupta, Kishan; Climer, Jason R.; Monaghan, Caitlin K.; Hasselmo, Michael E.

2012-01-01

Acetylcholine plays an important role in cognitive function, as shown by pharmacological manipulations that impact working memory, attention, episodic memory, and spatial memory function. Acetylcholine also shows striking modulatory influences on the cellular physiology of hippocampal and cortical neurons. Modeling of neural circuits provides a framework for understanding how the cognitive functions may arise from the influence of acetylcholine on neural and network dynamics. We review the influences of cholinergic manipulations on behavioral performance in working memory, attention, episodic memory, and spatial memory tasks, the physiological effects of acetylcholine on neural and circuit dynamics, and the computational models that provide insight into the functional relationships between the physiology and behavior. Specifically, we discuss the important role of acetylcholine in governing mechanisms of active maintenance in working memory tasks and in regulating network dynamics important for effective processing of stimuli in attention and episodic memory tasks. We also propose that theta rhythm plays a crucial role as an intermediary between the physiological influences of acetylcholine and behavior in episodic and spatial memory tasks. We conclude with a synthesis of the existing modeling work and highlight future directions that are likely to be rewarding given the existing state of the literature for both empiricists and modelers. PMID:22707936

Active retrieval facilitates across-episode binding by modulating the content of memory

PubMed Central

Bridge, Donna J.; Voss, Joel L.

2014-01-01

The contents of memory can be updated when information from the current episode is bound with content retrieved from previous episodes. Little is known regarding factors that determine the memory content that is subject to this across-episode binding. We tested whether across-episode binding preferentially occurs for memory content that is currently “active” and identified relevant neural correlates. After studying objects at specific locations on scene backgrounds, subjects performed one of two retrieval tasks for the objects on different scene backgrounds. In an active condition, subjects recalled object locations, whereas subjects merely dragged objects to predetermined locations in a passive condition. Immediately following each object-location retrieval event, a novel face appeared on a blank screen. We hypothesized that the original episode content would be active in memory during face encoding in the active condition, but not in the passive condition (despite seeing the same content in both conditions). A ramification of the active condition would thus be preferential binding of original episode content to novel faces, with no such across-episode binding in the passive condition. Indeed, memory for faces was better when tested on the original background scenes in the active relative to passive condition, indicating that original episode content was bound with the active condition faces, whereas this occurred to a lesser extent for the passive condition faces. Likewise, early-onset negative ERP effects reflected binding of the face to the original episode content in the active but not the passive condition. In contrast, binding in the passive condition occurred only when faces were physically displayed on the original scenes during recognition testing, and a very similar early-onset negative ERP effect signaled binding in this condition. ERP correlates of binding were thus similar for across-episode and within-episode binding (and were distinct from other encoding and retrieval ERP signals in both cases), indicating that active retrieval modulated when binding occurred, not the nature of the binding process per se. These results suggest that active retrieval promotes binding of new information with contents of memory, whereas without active retrieval, these unrelated pieces of information might be bound only when they are physically paired. PMID:25173711

Testing episodic memory in animals: a new approach.

PubMed

Griffiths, D P; Clayton, N S

2001-08-01

Episodic memory involves the encoding and storage of memories concerned with unique personal experiences and their subsequent recall, and it has long been the subject of intensive investigation in humans. According to Tulving's classical definition, episodic memory "receives and stores information about temporally dated episodes or events and temporal-spatial relations among these events." Thus, episodic memory provides information about the 'what' and 'when' of events ('temporally dated experiences') and about 'where' they happened ('temporal-spatial relations'). The storage and subsequent recall of this episodic information was thought to be beyond the memory capabilities of nonhuman animals. Although there are many laboratory procedures for investigating memory for discrete past episodes, until recently there were no previous studies that fully satisfied the criteria of Tulving's definition: they can all be explained in much simpler terms than episodic memory. However, current studies of memory for cache sites in food-storing jays provide an ethologically valid model for testing episodic-like memory in animals, thereby bridging the gap between human and animal studies memory. There is now a pressing need to adapt these experimental tests of episodic memory for other animals. Given the potential power of transgenic and knock-out procedures for investigating the genetic and molecular bases of learning and memory in laboratory rodents, not to mention the wealth of knowledge about the neuroanatomy and neurophysiology of the rodent hippocampus (a brain area heavily implicated in episodic memory), an obvious next step is to develop a rodent model of episodic-like memory based on the food-storing bird paradigm. The development of a rodent model system could make an important contribution to our understanding of the neural, molecular, and behavioral mechanisms of mammalian episodic memory.

The Influence of Encoding Strategy on Episodic Memory and Cortical Activity in Schizophrenia

PubMed Central

Haut, Kristen; Csernansky, John G.; Barch, Deanna M.

2005-01-01

Background: Recent work suggests that episodic memory deficits in schizophrenia may be related to disturbances of encoding or retrieval. Schizophrenia patients appear to benefit from instruction in episodic memory strategies. We tested the hypothesis that providing effective encoding strategies to schizophrenia patients enhances encoding-related brain activity and recognition performance. Methods: Seventeen schizophrenia patients and 26 healthy comparison subjects underwent functional magnetic resonance imaging scans while performing incidental encoding tasks of words and faces. Subjects were required to make either deep (abstract/concrete) or shallow (alphabetization) judgments for words and deep (gender) judgments for faces, followed by subsequent recognition tests. Results: Schizophrenia and comparison subjects recognized significantly more words encoded deeply than shallowly, activated regions in inferior frontal cortex (Brodmann area 45/47) typically associated with deep and successful encoding of words, and showed greater left frontal activation for the processing of words compared with faces. However, during deep encoding and material-specific processing (words vs. faces), participants with schizophrenia activated regions not activated by control subjects, including several in prefrontal cortex. Conclusions: Our findings suggest that a deficit in use of effective strategies influences episodic memory performance in schizophrenia and that abnormalities in functional brain activation persist even when such strategies are applied. PMID:15992522

Predicting Performance Breakdown in Pilots Through Objective Measures of Stress Sensitivity: Final Report

DTIC Science & Technology

1991-04-01

episodes . In recent years, however, there has been 15 increasing interest in implicit memory in which conscious recollection is not a necessity but...and Coanition, 13, 501-518. 32. Craik F.I.M. & Tulving E. (1975) Depth of processing and and the retention of words in episodic memory . Journal of...35. Baddeley A.D. & Warrington E.K. (1970) Amnesia and the distinction between long-and short-term memory . Journal of Verbal Learnina and Verbal

Posteromedial hyperactivation during episodic recognition among people with memory decline: findings from the WRAP study

PubMed Central

Nicholas, Christopher R.; Okonkwo, Ozioma C.; Bendlin, Barbara B.; Oh, Jennifer M.; Asthana, Sanjay; Rowley, Howard A.; Hermann, Bruce; Sager, Mark A.

2014-01-01

Episodic memory decline is one of the earliest preclinical symptoms of AD, and has been associated with an upregulation in the BOLD response in the prodromal stage (e.g. MCI) of AD. In a previous study, we observed upregulation in cognitively normal (CN) subjects with subclinical episodic memory decline compared to non-decliners. In light of this finding, we sought to determine if a separate cohort of Decliners will show increased brain activation compared to Stable subjects during episodic memory processing, and determine whether the BOLD effect was influenced by cerebral blood flow (CBF) or gray matter volume (GMV). Individuals were classified as a “Decliner” if scores on the Rey Auditory Verbal Learning Test (RAVLT) consistently fell≥1.5 SD below expected intra- or inter-individual levels. FMRI was used to compare activation during a facial recognition memory task in 90 Stable (age=59.1) and 34 Decliner (age=62.1, SD=5.9) CN middle-aged adults and 10 MCI patients (age=72.1, SD= 9.4). Arterial spin labeling and anatomical T1 MRI were used to measure resting CBF and GMV, respectively. Stables and Decliners performed similarly on the episodic recognition memory task and significantly better than MCI patients. Compared to Stables, Decliners showed increased BOLD signal in the left precuneus on the episodic memory task that was not explained by CBF or GMV, familial AD risk factors, or neuropsychological measures. These findings suggest that subtle changes in the BOLD signal reflecting altered neural function may be a relatively early phenomenon associated with memory decline. PMID:25332108

Recovery of episodic memory subprocesses in mild and complicated mild traumatic brain injury at 1 and 12 months post injury.

PubMed

Tayim, Fadi M; Flashman, Laura A; Wright, Matthew J; Roth, Robert M; McAllister, Thomas W

2016-11-01

Episodic memory complaints are commonly reported after traumatic brain injury (TBI). The contributions of specific memory subprocesses (encoding, consolidation, and retrieval), however, are not well understood in mild TBI (mTBI). In the present study, we evaluated subprocesses of episodic memory in patients with mTBI using the item-specific deficit approach (ISDA), which analyzes responses on list learning tasks at an item level. We also conducted exploratory analyses to evaluate the effects of complicated mTBI (comp-mTBI) on memory. We compared episodic verbal memory performance in mTBI (n = 92) at approximately 1 and 12 months post TBI, as well as in a healthy comparison (HC) group (n = 40) at equivalent time points. Episodic memory was assessed using the California Verbal Learning Test-2nd Edition (CVLT-II), and both standard CVLT-II scores and ISDA indices were evaluated. Compared to the HC group, the mTBI group showed significantly poorer encoding and learning across time, as measured by ISDA and CVLT-II. Further analyses of these mTBI subgroups [(noncomplicated mTBI (NC-mTBI, n = 77) and comp-mTBI (n = 15)], indicated that it was the comp-mTBI group who continued to demonstrate poorer encoding ability than the HC group. When the patient groups were directly compared, the NC-mTBI group improved slightly on the ISDA Encoding Deficit Index. While the comp-mTBI group worsened slightly over time, their poorer encoding ability was not likely clinically meaningful. These findings indicate that, while the NC-mTBI and HC groups' performances were comparable by 12 months, a primary, long-term deficit in encoding of auditory verbal information remained problematic in the comp-mTBI group.

Decoding individual episodic memory traces in the human hippocampus.

PubMed

Chadwick, Martin J; Hassabis, Demis; Weiskopf, Nikolaus; Maguire, Eleanor A

2010-03-23

In recent years, multivariate pattern analyses have been performed on functional magnetic resonance imaging (fMRI) data, permitting prediction of mental states from local patterns of blood oxygen-level-dependent (BOLD) signal across voxels. We previously demonstrated that it is possible to predict the position of individuals in a virtual-reality environment from the pattern of activity across voxels in the hippocampus. Although this shows that spatial memories can be decoded, substantially more challenging, and arguably only possible to investigate in humans, is whether it is feasible to predict which complex everyday experience, or episodic memory, a person is recalling. Here we document for the first time that traces of individual rich episodic memories are detectable and distinguishable solely from the pattern of fMRI BOLD signals across voxels in the human hippocampus. In so doing, we uncovered a possible functional topography in the hippocampus, with preferential episodic processing by some hippocampal regions over others. Moreover, our results imply that the neuronal traces of episodic memories are stable (and thus predictable) even over many re-activations. Finally, our data provide further evidence for functional differentiation within the medial temporal lobe, in that we show the hippocampus contains significantly more episodic information than adjacent structures. 2010 Elsevier Ltd. All rights reserved.

Metamemory monitoring in mild cognitive impairment: Evidence of a less accurate episodic feeling-of-knowing.

PubMed

Perrotin, Audrey; Belleville, Sylvie; Isingrini, Michel

2007-09-20

This study aimed at exploring metamemory and specifically the accuracy of memory monitoring in mild cognitive impairment (MCI) using an episodic memory feeling-of-knowing (FOK) procedure. To this end, 20 people with MCI and 20 matched control participants were compared on the episodic FOK task. Results showed that the MCI group made less accurate FOK predictions than the control group by overestimating their memory performance on a recognition task. The MCI overestimation behavior was found to be critically related to the severity of their cognitive decline. In the light of recent neuroanatomical models showing the involvement of a temporal-frontal network underlying accurate FOK predictions, the role of memory and executive processes was evaluated. Thus, participants were also administered memory and executive neuropsychological tests. Correlation analysis revealed a between-group differential pattern indicating that FOK accuracy was primarily related to memory abilities in people with MCI, whereas it was specifically related to executive functioning in control participants. The lesser ability of people with MCI to assess their memory status accurately on an episodic FOK task is discussed in relation to both their subjective memory complaints and to their actual memory deficits which might be mediated by the brain vulnerability of their hippocampus and medial temporal system. It is suggested that their memory weakness may lead people with MCI to use other less reliable forms of memory monitoring.

Video Game Training Enhances Visuospatial Working Memory and Episodic Memory in Older Adults

PubMed Central

Toril, Pilar; Reales, José M.; Mayas, Julia; Ballesteros, Soledad

2016-01-01

In this longitudinal intervention study with experimental and control groups, we investigated the effects of video game training on the visuospatial working memory (WM) and episodic memory of healthy older adults. Participants were 19 volunteer older adults, who received 15 1-h video game training sessions with a series of video games selected from a commercial package (Lumosity), and a control group of 20 healthy older adults. The results showed that the performance of the trainees improved significantly in all the practiced video games. Most importantly, we found significant enhancements after training in the trained group and no change in the control group in two computerized tasks designed to assess visuospatial WM, namely the Corsi blocks task and the Jigsaw puzzle task. The episodic memory and short-term memory of the trainees also improved. Gains in some WM and episodic memory tasks were maintained during a 3-month follow-up period. These results suggest that the aging brain still retains some degree of plasticity, and that video game training might be an effective intervention tool to improve WM and other cognitive functions in older adults. PMID:27199723

Effects of the BDNF Val66Met polymorphism and met allele load on declarative memory related neural networks.

PubMed

Dodds, Chris M; Henson, Richard N; Suckling, John; Miskowiak, Kamilla W; Ooi, Cinly; Tait, Roger; Soltesz, Fruzsina; Lawrence, Phil; Bentley, Graham; Maltby, Kay; Skeggs, Andrew; Miller, Sam R; McHugh, Simon; Bullmore, Edward T; Nathan, Pradeep J

2013-01-01

It has been suggested that the BDNF Val66Met polymorphism modulates episodic memory performance via effects on hippocampal neural circuitry. However, fMRI studies have yielded inconsistent results in this respect. Moreover, very few studies have examined the effect of met allele load on activation of memory circuitry. In the present study, we carried out a comprehensive analysis of the effects of the BDNF polymorphism on brain responses during episodic memory encoding and retrieval, including an investigation of the effect of met allele load on memory related activation in the medial temporal lobe. In contrast to previous studies, we found no evidence for an effect of BDNF genotype or met load during episodic memory encoding. Met allele carriers showed increased activation during successful retrieval in right hippocampus but this was contrast-specific and unaffected by met allele load. These results suggest that the BDNF Val66Met polymorphism does not, as previously claimed, exert an observable effect on neural systems underlying encoding of new information into episodic memory but may exert a subtle effect on the efficiency with which such information can be retrieved.

Mild traumatic brain injury: graph-model characterization of brain networks for episodic memory.

PubMed

Tsirka, Vasso; Simos, Panagiotis G; Vakis, Antonios; Kanatsouli, Kassiani; Vourkas, Michael; Erimaki, Sofia; Pachou, Ellie; Stam, Cornelis Jan; Micheloyannis, Sifis

2011-02-01

Episodic memory is among the cognitive functions that can be affected in the acute phase following mild traumatic brain injury (MTBI). The present study used EEG recordings to evaluate global synchronization and network organization of rhythmic activity during the encoding and recognition phases of an episodic memory task varying in stimulus type (kaleidoscope images, pictures, words, and pseudowords). Synchronization of oscillatory activity was assessed using a linear and nonlinear connectivity estimator and network analyses were performed using algorithms derived from graph theory. Twenty five MTBI patients (tested within days post-injury) and healthy volunteers were closely matched on demographic variables, verbal ability, psychological status variables, as well as on overall task performance. Patients demonstrated sub-optimal network organization, as reflected by changes in graph parameters in the theta and alpha bands during both encoding and recognition. There were no group differences in spectral energy during task performance or on network parameters during a control condition (rest). Evidence of less optimally organized functional networks during memory tasks was more prominent for pictorial than for verbal stimuli. Copyright © 2010 Elsevier B.V. All rights reserved.

Episodic and Semantic Memory Contribute to Familiar and Novel Episodic Future Thinking.

PubMed

Wang, Tong; Yue, Tong; Huang, Xi Ting

2016-01-01

Increasing evidence indicates that episodic future thinking (EFT) relies on both episodic and semantic memory; however, event familiarity may importantly affect the extent to which episodic and semantic memory contribute to EFT. To test this possibility, two behavioral experiments were conducted. In Experiment 1, we directly compared the proportion of episodic and semantic memory used in an EFT task. The results indicated that more episodic memory was used when imagining familiar future events compared with novel future events. Conversely, significantly more semantic memory was used when imagining novel events compared with familiar events. Experiment 2 aimed to verify the results of Experiment 1. In Experiment 2, we found that familiarity moderated the effect of priming the episodic memory system on EFT; particularly, it increased the time required to construct a standard familiar episodic future event, but did not significantly affect novel episodic event reaction time. Collectively, these findings support the hypothesis that event familiarity importantly moderates episodic and semantic memory's contribution to EFT.

Limited capacity of working memory in unihemispheric random walks implies conceivable slow dispersal.

PubMed

Wei, Kun; Zhong, Suchuan

2017-08-01

Phenomenologically inspired by dolphins' unihemispheric sleep, we introduce a minimal model for random walks with physiological memory. The physiological memory consists of long-term memory which includes unconscious implicit memory and conscious explicit memory, and working memory which serves as a multi-component system for integrating, manipulating and managing short-term storage. The model assumes that the sleeping state allows retrievals of episodic objects merely from the episodic buffer where these memory objects are invoked corresponding to the ambient objects and are thus object-oriented, together with intermittent but increasing use of implicit memory in which decisions are unconsciously picked up from historical time series. The process of memory decay and forgetting is constructed in the episodic buffer. The walker's risk attitude, as a product of physiological heuristics according to the performance of objected-oriented decisions, is imposed on implicit memory. The analytical results of unihemispheric random walks with the mixture of object-oriented and time-oriented memory, as well as the long-time behavior which tends to the use of implicit memory, are provided, indicating the common sense that a conservative risk attitude is inclinable to slow movement.

Neural Dynamics Associated with Semantic and Episodic Memory for Faces: Evidence from Multiple Frequency Bands

ERIC Educational Resources Information Center

Zion-Golumbic, Elana; Kutas, Marta; Bentin, Shlomo

2010-01-01

Prior semantic knowledge facilitates episodic recognition memory for faces. To examine the neural manifestation of the interplay between semantic and episodic memory, we investigated neuroelectric dynamics during the creation (study) and the retrieval (test) of episodic memories for famous and nonfamous faces. Episodic memory effects were evident…

Spatial and temporal episodic memory retrieval recruit dissociable functional networks in the human brain.

PubMed

Ekstrom, Arne D; Bookheimer, Susan Y

2007-10-01

Imaging, electrophysiological studies, and lesion work have shown that the medial temporal lobe (MTL) is important for episodic memory; however, it is unclear whether different MTL regions support the spatial, temporal, and item elements of episodic memory. In this study we used fMRI to examine retrieval performance emphasizing different aspects of episodic memory in the context of a spatial navigation paradigm. Subjects played a taxi-driver game ("yellowcab"), in which they freely searched for passengers and delivered them to specific landmark stores. Subjects then underwent fMRI scanning as they retrieved landmarks, spatial, and temporal associations from their navigational experience in three separate runs. Consistent with previous findings on item memory, perirhinal cortex activated most strongly during landmark retrieval compared with spatial or temporal source information retrieval. Both hippocampus and parahippocampal cortex activated significantly during retrieval of landmarks, spatial associations, and temporal order. We found, however, a significant dissociation between hippocampal and parahippocampal cortex activations, with spatial retrieval leading to greater parahippocampal activation compared with hippocampus and temporal order retrieval leading to greater hippocampal activation compared with parahippocampal cortex. Our results, coupled with previous findings, demonstrate that the hippocampus and parahippocampal cortex are preferentially recruited during temporal order and spatial association retrieval--key components of episodic "source" memory.

Long-term memory following transient global amnesia: an investigation of episodic and semantic memory.

PubMed

Guillery-Girard, B; Quinette, P; Desgranges, B; Piolino, P; Viader, F; de la Sayette, V; Eustache, F

2006-11-01

Several studies noted persistence of memory impairment following an episode of transient global amnesia (TGA) with standard tests. To specify long-term memory impairments in a group of patients selected with stringent criteria. Both retrograde and anterograde memory were investigated in 32 patients 13-67 months after a TGA episode with original tasks encompassing retrograde semantic memory (academic, public and personal knowledge), retrograde episodic memory (autobiographical events) and anterograde episodic memory. Patients had preserved academic and public knowledge. Pathological scores were obtained in personal verbal fluency for the two most recent periods, and patients produced less autobiographical events than controls. However, when they were provided time to detail, memories were as episodic as in controls regardless of their remoteness. Anterograde episodic tasks revealed a mild but significant impairment of the capacity of re-living the condition of encoding, i.e. the moment at which words were presented. Patients who have suffered from an episode of TGA manifest deficits of memory focused on the retrieval of both recent semantic information and episodic memories and especially the capacity of re-living. These deficits may not result from a deterioration of memory per se but rather from difficulties in accessing memories.

General and social cognition in remitted first-episode schizophrenia patients: a comparative study.

PubMed

Caldiroli, Alice; Buoli, Massimiliano; Serati, Marta; Cahn, Wiepke; Altamura, A Carlo

2016-10-01

The aim of this paper was to investigate whether both neurocognitive and social cognitive performances were different between remitted first-episode schizophrenia patients, non-remitters and healthy controls (HC). We assessed social cognition (Degraded Facial Affect Recognition Task-DFAR and Emotional Mentalizing Task-EMT) and neurocognition (Wechsler Adult Intelligence Scale and Word Learning Test-WLT) in 174 remitted first-episode schizophrenia patients, 110 non-remitted first-episode schizophrenia patients and 320 HC. Multivariate analyses of variance with age, gender and IQ as covariates (MANCOVA) were performed to compare mean cognitive test scores between the three groups. Remitted first-episode schizophrenia patients performed significantly worse than HC only in one verbal memory task (WLT immediate recall; p = 0.004); in the same test, they were significantly better than non-remitters (p = 0.027). Non-remitted first-episode schizophrenia patients, differently from remitters, performed significantly worse than HC in terms of social cognition (EMT-p < 0.05 and DFAR-p < 0.05). Remitted first-episode schizophrenia patients presented worse cognitive performance than HC in verbal memory tasks, but not in facial affect recognition and in ToM, while non-remitters did; these results suggest that neurocognitive deficits are the core hallmark of schizophrenia and that social cognition is relatively unaffected in remitted patients after their first episode.

Histopathologic subtype of hippocampal sclerosis and episodic memory performance before and after temporal lobectomy for epilepsy.

PubMed

Saghafi, Shahram; Ferguson, Lisa; Hogue, Olivia; Gales, Jordan M; Prayson, Richard; Busch, Robyn M

2018-04-01

The International League Against Epilepsy (ILAE) proposed a classification system for hippocampal sclerosis (HS) based on location and extent of hippocampal neuron loss. The literature debates the usefulness of this classification system when studying memory in people with temporal lobe epilepsy (TLE) and determining memory outcome after temporal lobe resection (TLR). This study further explores the relationship between HS ILAE subtypes and episodic memory performance in patients with TLE and examines memory outcomes after TLR. This retrospective study identified 213 patients with TLE who underwent TLR and had histopathological evidence of HS (HS ILAE type 1a = 92; type 1b = 103; type 2 = 18). Patients completed the Wechsler Memory Scale-3rd Edition prior to surgery, and 78% of patients had postoperative scores available. Linear regressions examined differences in preoperative memory scores as a function of pathology classification, controlling for potential confounders. Fisher's exact tests were used to compare pathology subtypes on the magnitude of preoperative memory impairment and the proportion of patients who experienced clinically meaningful postoperative memory decline. Individuals with HS ILAE type 2 demonstrated better preoperative verbal memory performance than patients with HS ILAE type 1; however, individual data revealed verbal and visual episodic memory impairments in many patients with HS ILAE type 2. The base rate of postoperative memory decline was similar among all 3 pathology groups. This is the largest reported overall sample and the largest subset of patients with HS ILAE type 2. Group data suggest that patients with HS ILAE type 2 perform better on preoperative memory measures, but individually there were no differences in the magnitude of memory impairment. Following surgery, there were no statistically significant differences between groups in the proportion of patients who declined. Future research should focus on quantitative measurements of hippocampal neuronal loss, and multicenter collaboration is encouraged. Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.

Aberrant prefrontal beta oscillations predict episodic memory encoding deficits in schizophrenia.

PubMed

Meconi, Federica; Anderl-Straub, Sarah; Raum, Heidelore; Landgrebe, Michael; Langguth, Berthold; Bäuml, Karl-Heinz T; Hanslmayr, Simon

Verbal episodic memory is one of the core cognitive functions affected in patients with schizophrenia (SZ). Although this verbal memory impairment in SZ is a well-known finding, our understanding about its underlying neurophysiological mechanisms is rather scarce. Here we address this issue by recording brain oscillations during a memory task in a sample of healthy controls and patients with SZ. Brain oscillations represent spectral fingerprints of specific neurocognitive operations and are therefore a promising tool to identify neurocognitive mechanisms that are affected by SZ. Healthy controls showed a prominent suppression of left prefrontal beta oscillatory activity during successful memory formation, which replicates several previous oscillatory memory studies. In contrast, patients failed to exhibit such a left prefrontal beta power suppression. Utilizing a new topographical pattern similarity approach, we further demonstrate that the degree of similarity between a patient's beta power decrease to that of the controls reliably predicted memory performance. This relationship between beta power decreases and memory was such that the patients' memory performance improved as they showed a more similar topographical beta desynchronization pattern compared to that of healthy controls. Together, these findings support left prefrontal beta desynchronization as the spectral fingerprint of verbal episodic memory formation, likely indicating deep semantic processing of verbal material. These findings also demonstrate that left prefrontal beta power suppression (or lack thereof) during memory encoding are a reliable biomarker for the observed encoding impairments in SZ in verbal memory.

Episodic memory impairment in Addison's disease: results from a telephonic cognitive assessment.

PubMed

Henry, Michelle; Thomas, Kevin G F; Ross, Ian L

2014-06-01

Patients with Addison's disease frequently self-report memory and attention difficulties, even when on standard replacement therapy. However, few published studies examine, using objective measures and assessing across multiple domains, the cognitive functioning of Addison's disease patients relative to healthy controls. The primary aim of this study was to investigate whether the previously reported subjective cognitive deficits in Addison's disease are confirmed by objective measures. Conducting comprehensive neuropsychological assessments of patients with relatively rare clinical disorders, such as Addison's disease, is challenging because access to those patients is often limited, and because their medical condition might prevent extended testing sessions. Brief telephonic cognitive assessments are a useful tool in such circumstances. Hence, we administered the Brief Test of Adult Cognition by Telephone to 27 Addison's disease patients and 27 matched healthy controls. The instrument provides objective assessment of episodic memory, working memory, executive functioning, reasoning, and speed of processing. Statistical analyses confirmed that, as expected, patients performed significantly more poorly than controls on the episodic memory subtest. There were, however, no significant between-group differences on the attention, executive functioning, reasoning, and speed of processing subtests. Furthermore, patients with a longer duration of illness performed more poorly across all domains of cognition. We conclude that, for Addison's disease patients, previously reported subjective cognitive deficits are matched by objective impairment, but only in the domain of episodic memory. Future research might investigate (a) whether these memory deficits are material-specific (i.e., whether non-verbal memory is also affected), and (b) the neurobiological mechanisms underlying these deficits.

Contribution of the Cholinergic System to Verbal Memory Performance in Mild Cognitive Impairment.

PubMed

Peter, Jessica; Lahr, Jacob; Minkova, Lora; Lauer, Eliza; Grothe, Michel J; Teipel, Stefan; Köstering, Lena; Kaller, Christoph P; Heimbach, Bernhard; Hüll, Michael; Normann, Claus; Nissen, Christoph; Reis, Janine; Klöppel, Stefan

2016-06-18

Acetylcholine is critically involved in modulating learning and memory function, which both decline in neurodegeneration. It remains unclear to what extent structural and functional changes in the cholinergic system contribute to episodic memory dysfunction in mild cognitive impairment (MCI), in addition to hippocampal degeneration. A better understanding is critical, given that the cholinergic system is the main target of current symptomatic treatment in mild to moderate Alzheimer's disease. We simultaneously assessed the structural and functional integrity of the cholinergic system in 20 patients with MCI and 20 matched healthy controls and examined their effect on verbal episodic memory via multivariate regression analyses. Mediating effects of either cholinergic function or hippocampal volume on the relationship between cholinergic structure and episodic memory were computed. In MCI, a less intact structure and function of the cholinergic system was found. A smaller cholinergic structure was significantly correlated with a functionally more active cholinergic system in patients, but not in controls. This association was not modulated by age or disease severity, arguing against compensational processes. Further analyses indicated that neither functional nor structural changes in the cholinergic system influence verbal episodic memory at the MCI stage. In fact, those associations were fully mediated by hippocampal volume. Although the cholinergic system is structurally and functionally altered in MCI, episodic memory dysfunction results primarily from hippocampal neurodegeneration, which may explain the inefficiency of cholinergic treatment at this disease stage.

Making the case that episodic recollection is attributable to operations occurring at retrieval rather than to content stored in a dedicated subsystem of long-term memory.

PubMed

Klein, Stanley B

2013-01-01

Episodic memory often is conceptualized as a uniquely human system of long-term memory that makes available knowledge accompanied by the temporal and spatial context in which that knowledge was acquired. Retrieval from episodic memory entails a form of first-person subjectivity called autonoetic consciousness that provides a sense that a recollection was something that took place in the experiencer's personal past. In this paper I expand on this definition of episodic memory. Specifically, I suggest that (1) the core features assumed unique to episodic memory are shared by semantic memory, (2) episodic memory cannot be fully understood unless one appreciates that episodic recollection requires the coordinated function of a number of distinct, yet interacting, "enabling" systems. Although these systems-ownership, self, subjective temporality, and agency-are not traditionally viewed as memorial in nature, each is necessary for episodic recollection and jointly they may be sufficient, and (3) the type of subjective awareness provided by episodic recollection (autonoetic) is relational rather than intrinsic-i.e., it can be lost in certain patient populations, thus rendering episodic memory content indistinguishable from the content of semantic long-term memory.

How do episodic and semantic memory contribute to episodic foresight in young children?

PubMed

Martin-Ordas, Gema; Atance, Cristina M; Caza, Julian S

2014-01-01

Humans are able to transcend the present and mentally travel to another time, place, or perspective. Mentally projecting ourselves backwards (i.e., episodic memory) or forwards (i.e., episodic foresight) in time are crucial characteristics of the human memory system. Indeed, over the past few years, episodic memory has been argued to be involved both in our capacity to retrieve our personal past experiences and in our ability to imagine and foresee future scenarios. However, recent theory and findings suggest that semantic memory also plays a significant role in imagining future scenarios. We draw on Tulving's definition of episodic and semantic memory to provide a critical analysis of their role in episodic foresight tasks described in the developmental literature. We conclude by suggesting future directions of research that could further our understanding of how both episodic memory and semantic memory are intimately connected to episodic foresight.

How do episodic and semantic memory contribute to episodic foresight in young children?

PubMed Central

Martin-Ordas, Gema; Atance, Cristina M.; Caza, Julian S.

2014-01-01

Humans are able to transcend the present and mentally travel to another time, place, or perspective. Mentally projecting ourselves backwards (i.e., episodic memory) or forwards (i.e., episodic foresight) in time are crucial characteristics of the human memory system. Indeed, over the past few years, episodic memory has been argued to be involved both in our capacity to retrieve our personal past experiences and in our ability to imagine and foresee future scenarios. However, recent theory and findings suggest that semantic memory also plays a significant role in imagining future scenarios. We draw on Tulving’s definition of episodic and semantic memory to provide a critical analysis of their role in episodic foresight tasks described in the developmental literature. We conclude by suggesting future directions of research that could further our understanding of how both episodic memory and semantic memory are intimately connected to episodic foresight. PMID:25071690

Effect of normal aging and of Alzheimer's disease on, episodic memory.

PubMed

Le Moal, S; Reymann, J M; Thomas, V; Cattenoz, C; Lieury, A; Allain, H

1997-01-01

Performances of 12 patients with Alzheimer's disease (AD), 15 healthy elderly subjects and 20 young healthy volunteers were compared on two episodic memory tests. The first, a learning test of semantically related words, enabled an assessment of the effect of semantic relationships on word learning by controlling the encoding and retrieval processes. The second, a dual coding test, is about the assessment of automatic processes operating during drawings encoding. The results obtained demonstrated quantitative and qualitative differences between the population. Manifestations of episodic memory deficit in AD patients were shown not only by lower performance scores than in elderly controls, but also by the lack of any effect of semantic cues and the production of a large number of extra-list intrusions. Automatic processes underlying dual coding appear to be spared in AD, although more time is needed to process information than in young or elderly subjects. These findings confirm former data and emphasize the preservation of certain memory processes (dual coding) in AD which could be used in future therapeutic approaches.

The Role of Episodic Memory in Controlled Evaluative Judgments about Attitudes: An Event-Related Potential Study

ERIC Educational Resources Information Center

Johnson, Ray, Jr.; Simon, Elizabeth J.; Henkell, Heather; Zhu, John

2011-01-01

Event-related potentials (ERPs) are unique in their ability to provide information about the timing of activity in the neural networks that perform complex cognitive processes. Given the dearth of extant data from normal controls on the question of whether attitude representations are stored in episodic or semantic memory, the goal here was to…

Temporal Clustering and Sequencing in Short-Term Memory and Episodic Memory

ERIC Educational Resources Information Center

Farrell, Simon

2012-01-01

A model of short-term memory and episodic memory is presented, with the core assumptions that (a) people parse their continuous experience into episodic clusters and (b) items are clustered together in memory as episodes by binding information within an episode to a common temporal context. Along with the additional assumption that information…

Evaluating the developmental trajectory of the episodic buffer component of working memory and its relation to word recognition in children.

PubMed

Wang, Shinmin; Allen, Richard J; Lee, Jun Ren; Hsieh, Chia-En

2015-05-01

The creation of temporary bound representation of information from different sources is one of the key abilities attributed to the episodic buffer component of working memory. Whereas the role of working memory in word learning has received substantial attention, very little is known about the link between the development of word recognition skills and the ability to bind information in the episodic buffer of working memory and how it may develop with age. This study examined the performance of Grade 2 children (8 years old), Grade 3 children (9 years old), and young adults on a task designed to measure their ability to bind visual and auditory-verbal information in working memory. Children's performance on this task significantly correlated with their word recognition skills even when chronological age, memory for individual elements, and other possible reading-related factors were taken into account. In addition, clear developmental trajectories were observed, with improvements in the ability to hold temporary bound information in working memory between Grades 2 and 3, and between the child and adult groups, that were independent from memory for the individual elements. These findings suggest that the capacity to temporarily bind novel auditory-verbal information to visual form in working memory is linked to the development of word recognition in children and improves with age. Copyright © 2015 Elsevier Inc. All rights reserved.

Memory development in the second year: for events or locations?

PubMed

Russell, James; Thompson, Doreen

2003-04-01

We employed an object-placement/object-removal design, inspired by recent work on 'episodic-like' memory in scrub jays (Clayton, N. S., & Dickinson, A. (1998). Episodic-like memory during cache recovery by scrub jays. Nature, 395, 272-274), to examine the possibility that children in the second year of life have event-based memories. In one task, a successful search could have been due to the recall of an object-removal event. In the second task, a successful search could only have been caused by recall of where objects were located. Success was general in the oldest group of children (21-25 months), while performance was broadly similar on the two tasks. The parsimonious interpretation of this outcome is that the first task was performed by location memory, not by event memory. We place these data in the context of object permanence development.

Out-of-body–induced hippocampal amnesia

PubMed Central

Bergouignan, Loretxu; Nyberg, Lars; Ehrsson, H. Henrik

2014-01-01

Theoretical models have suggested an association between the ongoing experience of the world from the perspective of one’s own body and hippocampus-based episodic memory. This link has been supported by clinical reports of long-term episodic memory impairments in psychiatric conditions with dissociative symptoms, in which individuals feel detached from themselves as if having an out-of-body experience. Here, we introduce an experimental approach to examine the necessary role of perceiving the world from the perspective of one’s own body for the successful episodic encoding of real-life events. While participants were involved in a social interaction, an out-of-body illusion was elicited, in which the sense of bodily self was displaced from the real body to the other end of the testing room. This condition was compared with a well-matched in-body illusion condition, in which the sense of bodily self was colocalized with the real body. In separate recall sessions, performed ∼1 wk later, we assessed the participants’ episodic memory of these events. The results revealed an episodic recollection deficit for events encoded out-of-body compared with in-body. Functional magnetic resonance imaging indicated that this impairment was specifically associated with activity changes in the posterior hippocampus. Collectively, these findings show that efficient hippocampus-based episodic-memory encoding requires a first-person perspective of the natural spatial relationship between the body and the world. Our observations have important implications for theoretical models of episodic memory, neurocognitive models of self, embodied cognition, and clinical research into memory deficits in psychiatric disorders. PMID:24616529

Out-of-body-induced hippocampal amnesia.

PubMed

Bergouignan, Loretxu; Nyberg, Lars; Ehrsson, H Henrik

2014-03-25

Theoretical models have suggested an association between the ongoing experience of the world from the perspective of one's own body and hippocampus-based episodic memory. This link has been supported by clinical reports of long-term episodic memory impairments in psychiatric conditions with dissociative symptoms, in which individuals feel detached from themselves as if having an out-of-body experience. Here, we introduce an experimental approach to examine the necessary role of perceiving the world from the perspective of one's own body for the successful episodic encoding of real-life events. While participants were involved in a social interaction, an out-of-body illusion was elicited, in which the sense of bodily self was displaced from the real body to the other end of the testing room. This condition was compared with a well-matched in-body illusion condition, in which the sense of bodily self was colocalized with the real body. In separate recall sessions, performed ∼1 wk later, we assessed the participants' episodic memory of these events. The results revealed an episodic recollection deficit for events encoded out-of-body compared with in-body. Functional magnetic resonance imaging indicated that this impairment was specifically associated with activity changes in the posterior hippocampus. Collectively, these findings show that efficient hippocampus-based episodic-memory encoding requires a first-person perspective of the natural spatial relationship between the body and the world. Our observations have important implications for theoretical models of episodic memory, neurocognitive models of self, embodied cognition, and clinical research into memory deficits in psychiatric disorders.

Rats Remember Items in Context Using Episodic Memory.

PubMed

Panoz-Brown, Danielle; Corbin, Hannah E; Dalecki, Stefan J; Gentry, Meredith; Brotheridge, Sydney; Sluka, Christina M; Wu, Jie-En; Crystal, Jonathon D

2016-10-24

Vivid episodic memories in people have been characterized as the replay of unique events in sequential order [1-3]. Animal models of episodic memory have successfully documented episodic memory of a single event (e.g., [4-8]). However, a fundamental feature of episodic memory in people is that it involves multiple events, and notably, episodic memory impairments in human diseases are not limited to a single event. Critically, it is not known whether animals remember many unique events using episodic memory. Here, we show that rats remember many unique events and the contexts in which the events occurred using episodic memory. We used an olfactory memory assessment in which new (but not old) odors were rewarded using 32 items. Rats were presented with 16 odors in one context and the same odors in a second context. To attain high accuracy, the rats needed to remember item in context because each odor was rewarded as a new item in each context. The demands on item-in-context memory were varied by assessing memory with 2, 3, 5, or 15 unpredictable transitions between contexts, and item-in-context memory survived a 45 min retention interval challenge. When the memory of item in context was put in conflict with non-episodic familiarity cues, rats relied on item in context using episodic memory. Our findings suggest that rats remember multiple unique events and the contexts in which these events occurred using episodic memory and support the view that rats may be used to model fundamental aspects of human cognition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Creativity and Memory: Effects of an Episodic-Specificity Induction on Divergent Thinking.

PubMed

Madore, Kevin P; Addis, Donna Rose; Schacter, Daniel L

2015-09-01

People produce more episodic details when imagining future events and solving means-end problems after receiving an episodic-specificity induction-brief training in recollecting details of a recent event-than after receiving a control induction not focused on episodic retrieval. Here we show for the first time that an episodic-specificity induction also enhances divergent creative thinking. In Experiment 1, participants exhibited a selective boost on a divergent-thinking task (generating unusual uses of common objects) after a specificity induction compared with a control induction; by contrast, performance following the two inductions was similar on an object association task thought to involve little divergent thinking. In Experiment 2, we replicated the specificity-induction effect on divergent thinking using a different control induction, and also found that participants performed similarly on a convergent-thinking task following the two inductions. These experiments provide novel evidence that episodic memory is involved in divergent creative thinking. © The Author(s) 2015.

Cognitive functioning following stabilisation from first episode mania.

PubMed

Daglas, Rothanthi; Allott, Kelly; Yücel, Murat; Henry, Lisa P; Macneil, Craig A; Hasty, Melissa K; Berk, Michael; Cotton, Sue M

2017-12-18

The purpose of this study was to examine cognitive functioning in people following first-episode mania relative to a demographically similar healthy control group. Forty-one patients, who had recently stabilised from a first manic episode, and twenty-one healthy controls, were compared in an extensive cognitive assessment. First-episode mania participants had significantly lower Full-Scale IQ (FSIQ) relative to healthy controls; however, this finding could be driven by premorbid differences in intellectual functioning. There were no significant differences between groups in Verbal IQ (VIQ) and Performance IQ (PIQ). First-episode mania participants performed significantly poorer than healthy controls in processing speed, verbal learning and memory, working memory, and cognitive flexibility with medium-to-large effects. There were no group differences in other measures of cognition. Participants following first-episode mania have poorer global intelligence than healthy controls, and have cognitive difficulties in some, but not all areas of cognitive functioning. This highlights the importance of early intervention and cognitive assessment in the early course of the disorder.

Effects of BDNF polymorphism and physical activity on episodic memory in the elderly: a cross sectional study.

PubMed

Canivet, Anne; Albinet, Cédric T; André, Nathalie; Pylouster, Jean; Rodríguez-Ballesteros, Montserrat; Kitzis, Alain; Audiffren, Michel

2015-01-01

The brain-derived neurotrophic factor (BDNF) concentration is highest in the hippocampus compared with that in other brain structures and affects episodic memory, a cognitive function that is impaired in older adults. According to the neurotrophic hypothesis, BDNF released during physical activity enhances brain plasticity and consequently brain health. However, even if the physical activity level is involved in the secretion of neurotrophin, this protein is also under the control of a specific gene. The aim of the present study was to examine the effect of the interaction between physical activity and BDNF Val66Met (rs6265), a genetic polymorphism, on episodic memory. Two hundred and five volunteers aged 55 and older with a Mini Mental State Examination score ≥ 24 participated in this study. Four groups of participants were established according to their physical activity level and polymorphism BDNF profile (Active Val homozygous, Inactive Val homozygous, Active Met carriers, Inactive Met carriers). Episodic memory was evaluated based on the delayed recall of the Logical Memory test of the MEM III battery. As expected, the physical activity level interacted with BDNF polymorphism to affect episodic memory performance (p < .05). The active Val homozygous participants significantly outperformed the active Met carriers and inactive Val homozygous participants. This study clearly demonstrates an interaction between physical activity and BDNF Val66Met polymorphism that affects episodic memory in the elderly and confirms that physical activity contributes to the neurotrophic mechanism implicated in cognitive health. The interaction shows that only participants with Val/Val polymorphism benefited from physical activity.

Hippocampal functional connectivity and episodic memory in early childhood

PubMed Central

Riggins, Tracy; Geng, Fengji; Blankenship, Sarah L.; Redcay, Elizabeth

2016-01-01

Episodic memory relies on a distributed network of brain regions, with the hippocampus playing a critical and irreplaceable role. Few studies have examined how changes in this network contribute to episodic memory development early in life. The present addressed this gap by examining relations between hippocampal functional connectivity and episodic memory in 4-and 6-year-old children (n=40). Results revealed similar hippocampal functional connectivity between age groups, which included lateral temporal regions, precuneus, and multiple parietal and prefrontal regions, and functional specialization along the longitudinal axis. Despite these similarities, developmental differences were also observed. Specifically, 3 (of 4) regions within the hippocampal memory network were positively associated with episodic memory in 6-year-old children, but negatively associated with episodic memory in 4-year-old children. In contrast, all 3 regions outside the hippocampal memory network were negatively associated with episodic memory in older children, but positively associated with episodic memory in younger children. These interactions are interpreted within an interactive specialization framework and suggest the hippocampus becomes functionally integrated with cortical regions that are part of the hippocampal memory network in adults and functionally segregated from regions unrelated to memory in adults, both of which are associated with age-related improvements in episodic memory ability. PMID:26900967

Hippocampal functional connectivity and episodic memory in early childhood.

PubMed

Riggins, Tracy; Geng, Fengji; Blankenship, Sarah L; Redcay, Elizabeth

2016-06-01

Episodic memory relies on a distributed network of brain regions, with the hippocampus playing a critical and irreplaceable role. Few studies have examined how changes in this network contribute to episodic memory development early in life. The present addressed this gap by examining relations between hippocampal functional connectivity and episodic memory in 4- and 6-year-old children (n=40). Results revealed similar hippocampal functional connectivity between age groups, which included lateral temporal regions, precuneus, and multiple parietal and prefrontal regions, and functional specialization along the longitudinal axis. Despite these similarities, developmental differences were also observed. Specifically, 3 (of 4) regions within the hippocampal memory network were positively associated with episodic memory in 6-year-old children, but negatively associated with episodic memory in 4-year-old children. In contrast, all 3 regions outside the hippocampal memory network were negatively associated with episodic memory in older children, but positively associated with episodic memory in younger children. These interactions are interpreted within an interactive specialization framework and suggest the hippocampus becomes functionally integrated with cortical regions that are part of the hippocampal memory network in adults and functionally segregated from regions unrelated to memory in adults, both of which are associated with age-related improvements in episodic memory ability. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

An episodic specificity induction enhances means-end problem solving in young and older adults.

PubMed

Madore, Kevin P; Schacter, Daniel L

2014-12-01

Episodic memory plays an important role not only in remembering past experiences, but also in constructing simulations of future experiences and solving means-end social problems. We recently found that an episodic specificity induction-brief training in recollecting details of past experiences-enhances performance of young and older adults on memory and imagination tasks. Here we tested the hypothesis that this specificity induction would also positively impact a means-end problem-solving task on which age-related changes have been linked to impaired episodic memory. Young and older adults received the specificity induction or a control induction before completing a means-end problem-solving task, as well as memory and imagination tasks. Consistent with previous findings, older adults provided fewer relevant steps on problem solving than did young adults, and their responses also contained fewer internal (i.e., episodic) details across the 3 tasks. There was no difference in the number of other (e.g., irrelevant) steps on problem solving or external (i.e., semantic) details generated on the 3 tasks as a function of age. Critically, the specificity induction increased the number of relevant steps and internal details (but not other steps or external details) that both young and older adults generated in problem solving compared with the control induction, as well as the number of internal details (but not external details) generated for memory and imagination. Our findings support the idea that episodic retrieval processes are involved in means-end problem solving, extend the range of tasks on which a specificity induction targets these processes, and show that the problem-solving performance of older adults can benefit from a specificity induction as much as that of young adults. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

An episodic specificity induction enhances means-end problem solving in young and older adults

PubMed Central

Madore, Kevin P.; Schacter, Daniel L.

2014-01-01

Episodic memory plays an important role not only in remembering past experiences, but also in constructing simulations of future experiences and solving means-end social problems. We recently found that an episodic specificity induction- brief training in recollecting details of past experiences- enhances performance of young and older adults on memory and imagination tasks. Here we tested the hypothesis that this specificity induction would also positively impact a means-end problem solving task on which age-related changes have been linked to impaired episodic memory. Young and older adults received the specificity induction or a control induction before completing a means-end problem solving task as well as memory and imagination tasks. Consistent with previous findings, older adults provided fewer relevant steps on problem solving than did young adults, and their responses also contained fewer internal (i.e., episodic) details across the three tasks. There was no difference in the number of other (e.g., irrelevant) steps on problem solving or external (i.e., semantic) details generated on the three tasks as a function of age. Critically, the specificity induction increased the number of relevant steps and internal details (but not other steps or external details) that both young and older adults generated in problem solving compared with the control induction, as well as the number of internal details (but not external details) generated for memory and imagination. Our findings support the idea that episodic retrieval processes are involved in means-end problem solving, extend the range of tasks on which a specificity induction targets these processes, and show that the problem solving performance of older adults can benefit from a specificity induction as much as that of young adults. PMID:25365688

Posteromedial hyperactivation during episodic recognition among people with memory decline: findings from the WRAP study.

PubMed

Nicholas, Christopher R; Okonkwo, Ozioma C; Bendlin, Barbara B; Oh, Jennifer M; Asthana, Sanjay; Rowley, Howard A; Hermann, Bruce; Sager, Mark A; Johnson, Sterling C

2015-12-01

Episodic memory decline is one of the earliest preclinical symptoms of AD, and has been associated with an upregulation in the BOLD response in the prodromal stage (e.g. MCI) of AD. In a previous study, we observed upregulation in cognitively normal (CN) subjects with subclinical episodic memory decline compared to non-decliners. In light of this finding, we sought to determine if a separate cohort of Decliners will show increased brain activation compared to Stable subjects during episodic memory processing, and determine whether the BOLD effect was influenced by cerebral blood flow (CBF) or gray matter volume (GMV). Individuals were classified as a "Decliner" if scores on the Rey Auditory Verbal Learning Test (RAVLT) consistently fell ≥ 1.5 SD below expected intra- or inter-individual levels. FMRI was used to compare activation during a facial recognition memory task in 90 Stable (age = 59.1) and 34 Decliner (age = 62.1, SD = 5.9) CN middle-aged adults and 10 MCI patients (age = 72.1, SD = 9.4). Arterial spin labeling and anatomical T1 MRI were used to measure resting CBF and GMV, respectively. Stables and Decliners performed similarly on the episodic recognition memory task and significantly better than MCI patients. Compared to Stables, Decliners showed increased BOLD signal in the left precuneus on the episodic memory task that was not explained by CBF or GMV, familial AD risk factors, or neuropsychological measures. These findings suggest that subtle changes in the BOLD signal reflecting altered neural function may be a relatively early phenomenon associated with memory decline.

Making the case that episodic recollection is attributable to operations occurring at retrieval rather than to content stored in a dedicated subsystem of long-term memory

PubMed Central

Klein, Stanley B.

2013-01-01

Episodic memory often is conceptualized as a uniquely human system of long-term memory that makes available knowledge accompanied by the temporal and spatial context in which that knowledge was acquired. Retrieval from episodic memory entails a form of first–person subjectivity called autonoetic consciousness that provides a sense that a recollection was something that took place in the experiencer's personal past. In this paper I expand on this definition of episodic memory. Specifically, I suggest that (1) the core features assumed unique to episodic memory are shared by semantic memory, (2) episodic memory cannot be fully understood unless one appreciates that episodic recollection requires the coordinated function of a number of distinct, yet interacting, “enabling” systems. Although these systems—ownership, self, subjective temporality, and agency—are not traditionally viewed as memorial in nature, each is necessary for episodic recollection and jointly they may be sufficient, and (3) the type of subjective awareness provided by episodic recollection (autonoetic) is relational rather than intrinsic—i.e., it can be lost in certain patient populations, thus rendering episodic memory content indistinguishable from the content of semantic long-term memory. PMID:23378832

[Neural Mechanisms Underlying the Processing of Temporal Information in Episodic Memory and Its Disturbance].

PubMed

Iwata, Saeko; Tsukiura, Takashi

2017-11-01

Episodic memory is defined as memory for personally experienced events, and includes memory content and contextual information of time and space. Previous neuroimaging and neuropsychological studies have demonstrated three possible roles of the temporal context in episodic memory. First, temporal information contributes to the arrangement of temporal order for sequential events in episodic memory, and this process is involved in the lateral prefrontal cortex. The second possible role of temporal information in episodic memory is the segregation between memories of multiple events, which are segregated by cues of different time information. The role of segregation is associated with the orbitofrontal regions including the orbitofrontal cortex and basal forebrain region. Third, temporal information in episodic memory plays an important role in the integration of multiple components into a coherent episodic memory, in which episodic components in the different modalities are combined by temporal information as an index. The role of integration is mediated by the medial temporal lobe including the hippocampus and parahippocampal gyrus. Thus, temporal information in episodic memory could be represented in multiple stages, which are involved in a network of the lateral prefrontal, orbitofrontal, and medial temporal lobe regions.

Episodic memory, semantic memory, and amnesia.

PubMed

Squire, L R; Zola, S M

1998-01-01

Episodic memory and semantic memory are two types of declarative memory. There have been two principal views about how this distinction might be reflected in the organization of memory functions in the brain. One view, that episodic memory and semantic memory are both dependent on the integrity of medial temporal lobe and midline diencephalic structures, predicts that amnesic patients with medial temporal lobe/diencephalic damage should be proportionately impaired in both episodic and semantic memory. An alternative view is that the capacity for semantic memory is spared, or partially spared, in amnesia relative to episodic memory ability. This article reviews two kinds of relevant data: 1) case studies where amnesia has occurred early in childhood, before much of an individual's semantic knowledge has been acquired, and 2) experimental studies with amnesic patients of fact and event learning, remembering and knowing, and remote memory. The data provide no compelling support for the view that episodic and semantic memory are affected differently in medial temporal lobe/diencephalic amnesia. However, episodic and semantic memory may be dissociable in those amnesic patients who additionally have severe frontal lobe damage.

Hearing loss is negatively related to episodic and semantic long-term memory but not to short-term memory.

PubMed

Rönnberg, Jerker; Danielsson, Henrik; Rudner, Mary; Arlinger, Stig; Sternäng, Ola; Wahlin, Ake; Nilsson, Lars-Göran

2011-04-01

To test the relationship between degree of hearing loss and different memory systems in hearing aid users. Structural equation modeling (SEM) was used to study the relationship between auditory and visual acuity and different cognitive and memory functions in an age-hetereogenous subsample of 160 hearing aid users without dementia, drawn from the Swedish prospective cohort aging study known as Betula (L.-G. Nilsson et al., 1997). Hearing loss was selectively and negatively related to episodic and semantic long-term memory (LTM) but not short-term memory (STM) performance. This held true for both ears, even when age was accounted for. Visual acuity alone, or in combination with auditory acuity, did not contribute to any acceptable SEM solution. The overall relationships between hearing loss and memory systems were predicted by the ease of language understanding model (J. Rönnberg, 2003), but the exact mechanisms of episodic memory decline in hearing aid users (i.e., mismatch/disuse, attentional resources, or information degradation) remain open for further experiments. The hearing aid industry should strive to design signal processing algorithms that are cognition friendly.

Auditory Memory Decay as Reflected by a New Mismatch Negativity Score Is Associated with Episodic Memory in Older Adults at Risk of Dementia

PubMed Central

Laptinskaya, Daria; Thurm, Franka; Küster, Olivia C.; Fissler, Patrick; Schlee, Winfried; Kolassa, Stephan; von Arnim, Christine A. F.; Kolassa, Iris-Tatjana

2018-01-01

The auditory mismatch negativity (MMN) is an event-related potential (ERP) peaking about 100–250 ms after the onset of a deviant tone in a sequence of identical (standard) tones. Depending on the interstimulus interval (ISI) between standard and deviant tones, the MMN is suitable to investigate the pre-attentive auditory discrimination ability (short ISIs, ≤ 2 s) as well as the pre-attentive auditory memory trace (long ISIs, >2 s). However, current results regarding the MMN as an index for mild cognitive impairment (MCI) and dementia are mixed, especially after short ISIs: while the majority of studies report positive associations between the MMN and cognition, others fail to find such relationships. To elucidate these so far inconsistent results, we investigated the validity of the MMN as an index for cognitive impairment exploring the associations between different MMN indices and cognitive performance, more specifically with episodic memory performance which is among the most affected cognitive domains in the course of Alzheimer’s dementia (AD), at baseline and at a 5-year-follow-up. We assessed the amplitude of the MMN for short ISI (stimulus onset asynchrony, SOA = 0.05 s) and for long ISI (3 s) in a neuropsychologically well-characterized cohort of older adults at risk of dementia (subjective memory impairment, amnestic and non-amnestic MCI; n = 57). Furthermore, we created a novel difference score (ΔMMN), defined as the difference between MMNs to short and to long ISI, as a measure to assess the decay of the auditory memory trace, higher values indicating less decay. ΔMMN and MMN amplitude after long ISI, but not the MMN amplitude after short ISI, was associated with episodic memory at baseline (β = 0.38, p = 0.003; β = −0.27, p = 0.047, respectively). ΔMMN, but not the MMN for long ISIs, was positively associated with episodic memory performance at the 5-year-follow-up (β = 0.57, p = 0.013). The results suggest that the MMN after long ISI might be suitable as an indicator for the decline in episodic memory and indicate ΔMMN as a potential biomarker for memory impairment in older adults at risk of dementia. PMID:29456500

Auditory Memory Decay as Reflected by a New Mismatch Negativity Score Is Associated with Episodic Memory in Older Adults at Risk of Dementia.

PubMed

Laptinskaya, Daria; Thurm, Franka; Küster, Olivia C; Fissler, Patrick; Schlee, Winfried; Kolassa, Stephan; von Arnim, Christine A F; Kolassa, Iris-Tatjana

2018-01-01

The auditory mismatch negativity (MMN) is an event-related potential (ERP) peaking about 100-250 ms after the onset of a deviant tone in a sequence of identical (standard) tones. Depending on the interstimulus interval (ISI) between standard and deviant tones, the MMN is suitable to investigate the pre-attentive auditory discrimination ability (short ISIs, ≤ 2 s) as well as the pre-attentive auditory memory trace (long ISIs, >2 s). However, current results regarding the MMN as an index for mild cognitive impairment (MCI) and dementia are mixed, especially after short ISIs: while the majority of studies report positive associations between the MMN and cognition, others fail to find such relationships. To elucidate these so far inconsistent results, we investigated the validity of the MMN as an index for cognitive impairment exploring the associations between different MMN indices and cognitive performance, more specifically with episodic memory performance which is among the most affected cognitive domains in the course of Alzheimer's dementia (AD), at baseline and at a 5-year-follow-up. We assessed the amplitude of the MMN for short ISI (stimulus onset asynchrony, SOA = 0.05 s) and for long ISI (3 s) in a neuropsychologically well-characterized cohort of older adults at risk of dementia (subjective memory impairment, amnestic and non-amnestic MCI; n = 57). Furthermore, we created a novel difference score (ΔMMN), defined as the difference between MMNs to short and to long ISI, as a measure to assess the decay of the auditory memory trace, higher values indicating less decay. ΔMMN and MMN amplitude after long ISI, but not the MMN amplitude after short ISI, was associated with episodic memory at baseline ( β = 0.38, p = 0.003; β = -0.27, p = 0.047, respectively). ΔMMN, but not the MMN for long ISIs, was positively associated with episodic memory performance at the 5-year-follow-up ( β = 0.57, p = 0.013). The results suggest that the MMN after long ISI might be suitable as an indicator for the decline in episodic memory and indicate ΔMMN as a potential biomarker for memory impairment in older adults at risk of dementia.

Elements of episodic-like memory in animal models.

PubMed

Crystal, Jonathon D

2009-03-01

Representations of unique events from one's past constitute the content of episodic memories. A number of studies with non-human animals have revealed that animals remember specific episodes from their past (referred to as episodic-like memory). The development of animal models of memory holds enormous potential for gaining insight into the biological bases of human memory. Specifically, given the extensive knowledge of the rodent brain, the development of rodent models of episodic memory would open new opportunities to explore the neuroanatomical, neurochemical, neurophysiological, and molecular mechanisms of memory. Development of such animal models holds enormous potential for studying functional changes in episodic memory in animal models of Alzheimer's disease, amnesia, and other human memory pathologies. This article reviews several approaches that have been used to assess episodic-like memory in animals. The approaches reviewed include the discrimination of what, where, and when in a radial arm maze, dissociation of recollection and familiarity, object recognition, binding, unexpected questions, and anticipation of a reproductive state. The diversity of approaches may promote the development of converging lines of evidence on the difficult problem of assessing episodic-like memory in animals.

They saw a movie: long-term memory for an extended audiovisual narrative.

PubMed

Furman, Orit; Dorfman, Nimrod; Hasson, Uri; Davachi, Lila; Dudai, Yadin

2007-06-01

We measured long-term memory for a narrative film. During the study session, participants watched a 27-min movie episode, without instructions to remember it. During the test session, administered at a delay ranging from 3 h to 9 mo after the study session, long-term memory for the movie was probed using a computerized questionnaire that assessed cued recall, recognition, and metamemory of movie events sampled approximately 20 sec apart. The performance of each group of participants was measured at a single time point only. The participants remembered many events in the movie even months after watching it. Analysis of performance, using multiple measures, indicates differences between recent (weeks) and remote (months) memory. While high-confidence recognition performance was a reliable index of memory throughout the measured time span, cued recall accuracy was higher for relatively recent information. Analysis of different content elements in the movie revealed differential memory performance profiles according to time since encoding. We also used the data to propose lower limits on the capacity of long-term memory. This experimental paradigm is useful not only for the analysis of behavioral performance that results from encoding episodes in a continuous real-life-like situation, but is also suitable for studying brain substrates and processes of real-life memory using functional brain imaging.

They saw a movie: Long-term memory for an extended audiovisual narrative

PubMed Central

Furman, Orit; Dorfman, Nimrod; Hasson, Uri; Davachi, Lila; Dudai, Yadin

2007-01-01

We measured long-term memory for a narrative film. During the study session, participants watched a 27-min movie episode, without instructions to remember it. During the test session, administered at a delay ranging from 3 h to 9 mo after the study session, long-term memory for the movie was probed using a computerized questionnaire that assessed cued recall, recognition, and metamemory of movie events sampled ∼20 sec apart. The performance of each group of participants was measured at a single time point only. The participants remembered many events in the movie even months after watching it. Analysis of performance, using multiple measures, indicates differences between recent (weeks) and remote (months) memory. While high-confidence recognition performance was a reliable index of memory throughout the measured time span, cued recall accuracy was higher for relatively recent information. Analysis of different content elements in the movie revealed differential memory performance profiles according to time since encoding. We also used the data to propose lower limits on the capacity of long-term memory. This experimental paradigm is useful not only for the analysis of behavioral performance that results from encoding episodes in a continuous real-life-like situation, but is also suitable for studying brain substrates and processes of real-life memory using functional brain imaging. PMID:17562897

Personality traits, autobiographical memory and knowledge of self and others: A comparative study in young people with autism spectrum disorder.

PubMed

Robinson, Sally; Howlin, Patricia; Russell, Ailsa

2017-04-01

The relationship between dissociable components of autobiographical memory (e.g. semantic personality traits and episodic memory retrieval) and other cognitive skills that are proposed to enable one to develop a sense of self (e.g. introspection) have not previously been explored for children with autism spectrum disorder. This study compared autobiographical memory (semantic and episodic) and knowledge of self (internal/external self-knowledge and introspection/mentalising abilities) in children (aged 11-18 years) with high-functioning autism spectrum disorder and typically developing controls (total N = 48). Novel and standard tasks were employed. Compared to typically developing controls, young people with autism spectrum disorder had autobiographical memory difficulties that were characterised by a reduction in the retrieval of semantic personality traits, with more initial prompts required to facilitate episodic memory retrieval and fewer episodic memories containing emotional and sensory information. Knowledge of the self and others was also impaired, with reduced introspection and poorer mentalising abilities. Young people with autism spectrum disorder were also identified as presenting with an atypical relationship between autobiographical memory and self-knowledge, which was significantly different from typically developing controls. Test performance is discussed in relation to the functions of autobiographical memory, with consideration of how these cognitive difficulties may contribute to clinical practices and the social and behavioural characteristics of autism spectrum disorder.

Flynn effects on sub-factors of episodic and semantic memory: parallel gains over time and the same set of determining factors.

PubMed

Rönnlund, Michael; Nilsson, Lars-Göran

2009-09-01

The study examined the extent to which time-related gains in cognitive performance, so-called Flynn effects, generalize across sub-factors of episodic memory (recall and recognition) and semantic memory (knowledge and fluency). We conducted time-sequential analyses of data drawn from the Betula prospective cohort study, involving four age-matched samples (35-80 years; N=2996) tested on the same battery of memory tasks on either of four occasions (1989, 1995, 1999, and 2004). The results demonstrate substantial time-related improvements on recall and recognition as well as on fluency and knowledge, with a trend of larger gains on semantic as compared with episodic memory [Rönnlund, M., & Nilsson, L. -G. (2008). The magnitude, generality, and determinants of Flynn effects on forms of declarative memory: Time-sequential analyses of data from a Swedish cohort study. Intelligence], but highly similar gains across the sub-factors. Finally, the association with markers of environmental change was similar, with evidence that historical increases in quantity of schooling was a main driving force behind the gains, both on the episodic and semantic sub-factors. The results obtained are discussed in terms of brain regions involved.

Anticholinergic drug use is associated with episodic memory decline in older adults without dementia.

PubMed

Papenberg, Goran; Bäckman, Lars; Fratiglioni, Laura; Laukka, Erika J; Fastbom, Johan; Johnell, Kristina

2017-07-01

Anticholinergic drug use is common in older adults and has been related to increased dementia risk. This suggests that users of these drugs may experience accelerated cognitive decline. So far, however, longitudinal data on this topic are absent and the available evidence is inconclusive with respect to effects on specific cognitive domains due to suboptimal control of confounding variables. We investigated whether anticholinergic medication use is associated with cognitive decline over 6 years in a population-based study of older adults (aged 60-90; n = 1473) without dementia. We found that users (n = 29) declined more on episodic memory over 6 years compared to nonusers (n = 1418). These results were independent of age, sex, education, overall drug intake, physical activity, depression, cardiovascular risk burden, and cardiovascular disease. By contrast, anticholinergic drug use was unrelated to performance in processing speed, semantic memory, short-term memory, verbal fluency, and global cognition (the Mini-Mental-State Examination). Our results suggest that effects of anticholinergics may be particularly detrimental to episodic memory in older adults, which supports the assertion that the cholinergic system plays an important role in episodic memory formation. Copyright © 2017 Elsevier Inc. All rights reserved.

Episodic memory and self-reference via semantic autobiographical memory: insights from an fMRI study in younger and older adults.

PubMed

Kalenzaga, Sandrine; Sperduti, Marco; Anssens, Adèle; Martinelli, Penelope; Devauchelle, Anne-Dominique; Gallarda, Thierry; Delhommeau, Marion; Lion, Stéphanie; Amado, Isabelle; Krebs, Marie-Odile; Oppenheim, Catherine; Piolino, Pascale

2014-01-01

Self-referential processing relies mainly on the medial prefrontal cortex (MPFC) and enhances memory encoding (i.e., Self-Reference Effect, SRE) as it improves the accuracy and richness of remembering in both young and older adults. However, studies on age-related changes in the neural correlates of the SRE on the subjective (i.e., autonoetic consciousness) and the objective (i.e., source memory) qualitative features of episodic memory are lacking. In the present fMRI study, we compared the effects of a self-related (semantic autobiographical memory task) and a non self-related (general semantic memory task) encoding condition on subsequent episodic memory retrieval. We investigated encoding-related activity during each condition in two groups of 19 younger and 16 older adults. Behaviorally, the SRE improved subjective memory performance in both groups but objective memory only in young adults. At the neural level, a direct comparison between self-related and non self-related conditions revealed that SRE mainly activated the cortical midline system, especially the MPFC, in both groups. Additionally, in older adults and regardless of the condition, greater activity was found in a fronto-parietal network. Overall, correlations were noted between source memory performance and activity in the MPFC (irrespective of age) and visual areas (mediated by age). Thus, the present findings expand evidence of the role of the MPFC in self-referential processing in the context of source memory benefit in both young and older adults using incidental encoding via semantic autobiographical memory. However, our finding suggests that its role is less effective in aging.

Episodic memory and self-reference via semantic autobiographical memory: insights from an fMRI study in younger and older adults

PubMed Central

Kalenzaga, Sandrine; Sperduti, Marco; Anssens, Adèle; Martinelli, Penelope; Devauchelle, Anne-Dominique; Gallarda, Thierry; Delhommeau, Marion; Lion, Stéphanie; Amado, Isabelle; Krebs, Marie-Odile; Oppenheim, Catherine; Piolino, Pascale

2015-01-01

Self-referential processing relies mainly on the medial prefrontal cortex (MPFC) and enhances memory encoding (i.e., Self-Reference Effect, SRE) as it improves the accuracy and richness of remembering in both young and older adults. However, studies on age-related changes in the neural correlates of the SRE on the subjective (i.e., autonoetic consciousness) and the objective (i.e., source memory) qualitative features of episodic memory are lacking. In the present fMRI study, we compared the effects of a self-related (semantic autobiographical memory task) and a non self-related (general semantic memory task) encoding condition on subsequent episodic memory retrieval. We investigated encoding-related activity during each condition in two groups of 19 younger and 16 older adults. Behaviorally, the SRE improved subjective memory performance in both groups but objective memory only in young adults. At the neural level, a direct comparison between self-related and non self-related conditions revealed that SRE mainly activated the cortical midline system, especially the MPFC, in both groups. Additionally, in older adults and regardless of the condition, greater activity was found in a fronto-parietal network. Overall, correlations were noted between source memory performance and activity in the MPFC (irrespective of age) and visual areas (mediated by age). Thus, the present findings expand evidence of the role of the MPFC in self-referential processing in the context of source memory benefit in both young and older adults using incidental encoding via semantic autobiographical memory. However, our finding suggests that its role is less effective in aging. PMID:25628546

The Composition of Episodic Memory.

ERIC Educational Resources Information Center

Underwood, Benton J.; And Others

This study examined the interrelationships among a number of episodic memory tasks and among various attributes of memory. A sample of 200 college students was tested for ten sessions; 28 different measures of episodic memory were obtained. In addition, five measures of semantic memory were available. Results indicated that episodic and semantic…

Interaction between attentional systems and episodic memory encoding: the impact of conflict on binding of information.

PubMed

Sperduti, Marco; Armougum, Allan; Makowski, Dominique; Blondé, Philippe; Piolino, Pascale

2017-12-01

Episodic memory (EM) is defined as a long-term memory system that stores information that can be retrieved along with details of the context of the original events (binding). Several studies have shown that manipulation of attention during encoding can impact subsequent memory performance. An influential model of attention distinguishes between three partially independent attentional networks: the alerting, the orienting and the executive or conflict resolution component. To date, the impact of the engagement of these sub-systems during encoding on item and relational context binding has not been investigated. Here, we developed a new task combining the Attentional Network Test and an incidental episodic memory encoding task to study this issue. We reported that when the alerting network was not solicited, resolving conflict hindered item encoding. Moreover, resolving conflict, independently of the cueing condition, had a negative impact on context binding. These novel findings could have a potential impact in the understanding EM formation, and memory disorders in different populations, including healthy elderly people.

Longitudinal patterns of semantic and episodic memory in frontotemporal lobar degeneration and Alzheimer's disease.

PubMed

Xie, Sharon X; Libon, David J; Wang, Xingmei; Massimo, Lauren; Moore, Peachie; Vesely, Luisa; Khan, Alea; Chatterjee, Anjan; Coslett, H Branch; Hurtig, Howard I; Liang, Tsao-Wei; Grossman, Murray

2010-03-01

The longitudinal assessment of episodic and semantic memory was obtained from 236 patients diagnosed with Alzheimer's disease (AD, n = 128) and with frontotemporal lobar degeneration (FTLD, n = 108), including patients with a social comportment/dysexecutive (SOC/EXEC) disorder, progressive nonfluent aphasia (PNFA), semantic dementia (SemD), and corticobasal syndrome (CBS). At the initial assessment, AD patients obtained a lower score on the delayed free recall test than other patients. Longitudinal analyses for delayed free recall found converging performance, with all patients reaching the same level of impairment as AD patients. On the initial evaluation for delayed recognition, AD patients also obtained lower scores than other groups. Longitudinal analyses for delayed recognition test performance found that AD patients consistently produced lower scores than other groups and no convergence between AD and other dementia groups was seen. For semantic memory, there were no initial between-group differences. However, longitudinal analyses for semantic memory revealed group differences over illness duration, with worse performance for SemD versus AD, PNFA, SOC/EXEC, and CBS patients. These data suggest the presence of specific longitudinal patterns of impairment for episodic and semantic memory in AD and FTLD patients suggesting that all forms of dementia do not necessarily converge into a single phenotype.

Memory Performance for Everyday Motivational and Neutral Objects Is Dissociable from Attention

PubMed Central

Schomaker, Judith; Wittmann, Bianca C.

2017-01-01

Episodic memory is typically better for items coupled with monetary reward or punishment during encoding. It is yet unclear whether memory is also enhanced for everyday objects with appetitive or aversive values learned through a lifetime of experience, and to what extent episodic memory enhancement for motivational and neutral items is attributable to attention. In a first experiment, we investigated attention to everyday motivational objects using eye-tracking during free-viewing and subsequently tested episodic memory using a remember/know procedure. Attention was directed more to aversive stimuli, as evidenced by longer viewing durations, whereas recollection was higher for both appetitive and aversive objects. In the second experiment, we manipulated the visual contrast of neutral objects through changes of contrast to further dissociate attention and memory encoding. While objects presented with high visual contrast were looked at longer, recollection was best for objects presented in unmodified, medium contrast. Generalized logistic mixed models on recollection performance showed that attention as measured by eye movements did not enhance subsequent memory, while motivational value (Experiment 1) and visual contrast (Experiment 2) had quadratic effects in opposite directions. Our findings suggest that an enhancement of incidental memory encoding for appetitive items can occur without an increase in attention and, vice versa, that enhanced attention towards salient neutral objects is not necessarily associated with memory improvement. Together, our results provide evidence for a double dissociation of attention and memory effects under certain conditions. PMID:28694774

The increase in medial prefrontal glutamate/glutamine concentration during memory encoding is associated with better memory performance and stronger functional connectivity in the human medial prefrontal–thalamus–hippocampus network

PubMed Central

Hong, Donghyun; Rohani Rankouhi, Seyedmorteza; Wiltfang, Jens; Fernández, Guillén; Norris, David G.; Tendolkar, Indira

2018-01-01

Abstract The classical model of the declarative memory system describes the hippocampus and its interactions with representational brain areas in posterior neocortex as being essential for the formation of long‐term episodic memories. However, new evidence suggests an extension of this classical model by assigning the medial prefrontal cortex (mPFC) a specific, yet not fully defined role in episodic memory. In this study, we utilized 1H magnetic resonance spectroscopy (MRS) and psychophysiological interaction (PPI) analysis to lend further support for the idea of a mnemonic role of the mPFC in humans. By using MRS, we measured mPFC γ‐aminobutyric acid (GABA) and glutamate/glutamine (GLx) concentrations before and after volunteers memorized face–name association. We demonstrate that mPFC GLx but not GABA levels increased during the memory task, which appeared to be related to memory performance. Regarding functional connectivity, we used the subsequent memory paradigm and found that the GLx increase was associated with stronger mPFC connectivity to thalamus and hippocampus for associations subsequently recognized with high confidence as opposed to subsequently recognized with low confidence/forgotten. Taken together, we provide new evidence for an mPFC involvement in episodic memory by showing a memory‐related increase in mPFC excitatory neurotransmitter levels that was associated with better memory and stronger memory‐related functional connectivity in a medial prefrontal–thalamus–hippocampus network. PMID:29488277

Autobiographical memory and structural brain changes in chronic phase TBI.

PubMed

Esopenko, Carrie; Levine, Brian

2017-04-01

Traumatic brain injury (TBI) is associated with a range of neuropsychological deficits, including attention, memory, and executive functioning attributable to diffuse axonal injury (DAI) with accompanying focal frontal and temporal damage. Although the memory deficit of TBI has been well characterized with laboratory tests, comparatively little research has examined retrograde autobiographical memory (AM) at the chronic phase of TBI, with no prior studies of unselected patients drawn directly from hospital admissions for trauma. Moreover, little is known about the effects of TBI on canonical episodic and non-episodic (e.g., semantic) AM processes. In the present study, we assessed the effects of chronic-phase TBI on AM in patients with focal and DAI spanning the range of TBI severity. Patients and socioeconomic- and age-matched controls were administered the Autobiographical Interview (AI) (Levine, Svoboda, Hay, Winocur, & Moscovitch, 2002) a widely used method for dissociating episodic and semantic elements of AM, along with tests of neuropsychological and functional outcome. Measures of episodic and non-episodic AM were compared with regional brain volumes derived from high-resolution structural magnetic resonance imaging (MRI). Severe TBI (but not mild or moderate TBI) was associated with reduced recall of episodic autobiographical details and increased recall of non-episodic details relative to healthy comparison participants. There were no significant associations between AM performance and neuropsychological or functional outcome measures. Within the full TBI sample, autobiographical episodic memory was associated with reduced volume distributed across temporal, parietal, and prefrontal regions considered to be part of the brain's AM network. These results suggest that TBI-related distributed volume loss affects episodic autobiographical recollection. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effects of road traffic and aircraft noise exposure on children's episodic memory: the RANCH project.

PubMed

Matheson, Mark; Clark, Charlotte; Martin, Rocio; van Kempen, Elise; Haines, Mary; Barrio, Isabel Lopez; Hygge, Staffan; Stansfeld, Stephen

2010-01-01

Previous studies have found that chronic exposure to aircraft noise has a negative effect on children's performance on tests of episodic memory. The present study extended the design of earlier studies in three ways: firstly, by examining the effects of two noise sources, aircraft and road traffic, secondly, by examining exposure-effect relationships, and thirdly, by carrying out parallel field studies in three European countries, allowing cross-country comparisons to be made. A total of 2844 children aged between 8 years 10 months and 12 years 10 months (mean age 10 years 6 months) completed classroom-based tests of cued recall, recognition memory and prospective memory. Questionnaires were also completed by the children and their parents in order to provide information about socioeconomic context. Multilevel modeling analysis revealed aircraft noise to be associated with an impairment of recognition memory in a linear exposure-effect relationship. The analysis also found road traffic noise to be associated with improved performance on cued recall in a linear exposure-effect relationship. No significant association was found between exposure to aircraft noise and cued recall or prospective memory. Likewise, no significant association was found between road traffic noise and recognition or prospective memory. Taken together, these findings indicate that exposure to aircraft noise and road traffic noise can impact on certain aspects of children's episodic memory.

Active retrieval facilitates across-episode binding by modulating the content of memory.

PubMed

Bridge, Donna J; Voss, Joel L

2014-10-01

The contents of memory can be updated when information from the current episode is bound with content retrieved from previous episodes. Little is known regarding factors that determine the memory content that is subject to this across-episode binding. We tested whether across-episode binding preferentially occurs for memory content that is currently "active" and identified relevant neural correlates. After studying objects at specific locations on scene backgrounds, subjects performed one of two retrieval tasks for the objects on different scene backgrounds. In an active condition, subjects recalled object locations, whereas subjects merely dragged objects to predetermined locations in a passive condition. Immediately following each object-location retrieval event, a novel face appeared on a blank screen. We hypothesized that the original episode content would be active in memory during face encoding in the active condition, but not in the passive condition (despite seeing the same content in both conditions). A ramification of the active condition would thus be preferential binding of original episode content to novel faces, with no such across-episode binding in the passive condition. Indeed, memory for faces was better when tested on the original background scenes in the active relative to passive condition, indicating that original episode content was bound with the active condition faces, whereas this occurred to a lesser extent for the passive condition faces. Likewise, early-onset negative ERP effects reflected binding of the face to the original episode content in the active but not the passive condition. In contrast, binding in the passive condition occurred only when faces were physically displayed on the original scenes during recognition testing, and a very similar early-onset negative ERP effect signaled binding in this condition. ERP correlates of binding were thus similar for across-episode and within-episode binding (and were distinct from other encoding and retrieval ERP signals in both cases), indicating that active retrieval modulated when binding occurred, not the nature of the binding process per se. These results suggest that active retrieval promotes binding of new information with contents of memory, whereas without active retrieval, these unrelated pieces of information might be bound only when they are physically paired. Copyright © 2014 Elsevier Ltd. All rights reserved.

Awareness of Memory Ability and Change: (In)Accuracy of Memory Self-Assessments in Relation to Performance.

PubMed

Rickenbach, Elizabeth Hahn; Agrigoroaei, Stefan; Lachman, Margie E

2015-03-01

Little is known about subjective assessments of memory abilities and decline among middle-aged adults or their association with objective memory performance in the general population. In this study we examined self-ratings of memory ability and change in relation to episodic memory performance in two national samples of middle-aged and older adults from the Midlife in the United States study (MIDUS II in 2005-06) and the Health and Retirement Study (HRS; every two years from 2002 to 2012). MIDUS (Study 1) participants (N=3,581) rated their memory compared to others their age and to themselves five years ago; HRS (Study 2) participants (N=14,821) rated their current memory and their memory compared to two years ago, with up to six occasions of longitudinal data over ten years. In both studies, episodic memory performance was the total number of words recalled in immediate and delayed conditions. When controlling for demographic and health correlates, self-ratings of memory abilities, but not subjective change, were related to performance. We examined accuracy by comparing subjective and objective memory ability and change. More than one third of the participants across the studies had self-assessments that were inaccurate relative to their actual level of performance and change, and accuracy differed as a function of demographic and health factors. Further understanding of self-awareness of memory abilities and change beginning in midlife may be useful for identifying early warning signs of decline, with implications regarding policies and practice for early detection and treatment of cognitive impairment.

Looking for episodic memory in animals and young children: prospects for a new minimalism.

PubMed

Clayton, Nicola S; Russell, James

2009-09-01

Because animals and young children cannot be interrogated about their experiences it is difficult to conduct research into their episodic memories. The approach to this issue adopted by Clayton and Dickinson [Clayton, N. S., & Dickinson, A. (1998). Episodic-like memory during cache recovery by scrub jays. Nature, 395, 272-274] was to take a conceptually minimalist definition of episodic memory, in terms of integrating information about what was done where and when [Tulving, E. (1972). Episodic and semantic memory. In E. Tulving, & W. Donaldson (Eds.), Organisation of memory (pp. 381-403). New York: Academic Press], and to refer to such memories as 'episodic-like'. Some claim, however, that because animals supposedly lack the conceptual abilities necessary for episodic recall one should properly call these memories 'semantic'. We address this debate with a novel approach to episodic memory, which is minimalist insofar as it focuses on the non-conceptual content of a re-experienced situation. It rests on Kantian assumptions about the necessary 'perspectival' features of any objective experience or re-experience. We show how adopting this perspectival approach can render an episodic interpretation of the animal data more plausible and can also reveal patterns in the mosaic of developmental evidence for episodic memory in humans.

Human Episodic Memory Retrieval Is Accompanied by a Neural Contiguity Effect.

PubMed

Folkerts, Sarah; Rutishauser, Ueli; Howard, Marc W

2018-04-25

Cognitive psychologists have long hypothesized that experiences are encoded in a temporal context that changes gradually over time. When an episodic memory is retrieved, the state of context is recovered-a jump back in time. We recorded from single units in the medial temporal lobe of epilepsy patients performing an item recognition task. The population vector changed gradually over minutes during presentation of the list. When a probe from the list was remembered with high confidence, the population vector reinstated the temporal context of the original presentation of that probe during study, a neural contiguity effect that provides a possible mechanism for behavioral contiguity effects. This pattern was only observed for well remembered probes; old probes that were not well remembered showed an anti-contiguity effect. These results constitute the first direct evidence that recovery of an episodic memory in humans is associated with retrieval of a gradually changing state of temporal context, a neural "jump back in time" that parallels the act of remembering. SIGNIFICANCE STATEMENT Episodic memory is the ability to relive a specific experience from one's life. For decades, researchers have hypothesized that, unlike other forms of memory that can be described as simple associations between stimuli, episodic memory depends on the recovery of a neural representation of spatiotemporal context. During study of a sequence of stimuli, the brain state of epilepsy patients changed slowly over at least a minute. When the participant remembered a particular event from the list, this gradually changing state was recovered. This provides direct confirmation of the prediction from computational models of episodic memory. The resolution of this point means that the study of episodic memory can focus on the mechanisms by which this representation of spatiotemporal context is maintained and sometimes recovered. Copyright © 2018 the authors 0270-6474/18/384200-12$15.00/0.

Semantic and episodic memory in children with temporal lobe epilepsy: do they relate to literacy skills?

PubMed

Lah, Suncica; Smith, Mary Lou

2014-01-01

Children with temporal lobe epilepsy are at risk for deficits in new learning (episodic memory) and literacy skills. Semantic memory deficits and double dissociations between episodic and semantic memory have recently been found in this patient population. In the current study we investigate whether impairments of these 2 distinct memory systems relate to literacy skills. 57 children with unilateral temporal lobe epilepsy completed tests of verbal memory (episodic and semantic) and literacy skills (reading and spelling accuracy, and reading comprehension). For the entire group, semantic memory explained over 30% of variance in each of the literacy domains. Episodic memory explained a significant, but rather small proportion (< 10%) of variance in reading and spelling accuracy, but not in reading comprehension. Moreover, when children with opposite patterns of specific memory impairments (intact semantic/impaired episodic, intact episodic/impaired semantic) were compared, significant reductions in literacy skills were evident only in children with semantic memory impairments, but not in children with episodic memory impairments relative to the norms and to children with temporal lobe epilepsy who had intact memory. Our study provides the first evidence for differential relations between episodic and semantic memory impairments and literacy skills in children with temporal lobe epilepsy. As such, it highlights the urgent need to consider semantic memory deficits in management of children with temporal lobe epilepsy and undertake further research into the nature of reading difficulties of children with semantic memory impairments.

The increase in medial prefrontal glutamate/glutamine concentration during memory encoding is associated with better memory performance and stronger functional connectivity in the human medial prefrontal-thalamus-hippocampus network.

PubMed

Thielen, Jan-Willem; Hong, Donghyun; Rohani Rankouhi, Seyedmorteza; Wiltfang, Jens; Fernández, Guillén; Norris, David G; Tendolkar, Indira

2018-06-01

The classical model of the declarative memory system describes the hippocampus and its interactions with representational brain areas in posterior neocortex as being essential for the formation of long-term episodic memories. However, new evidence suggests an extension of this classical model by assigning the medial prefrontal cortex (mPFC) a specific, yet not fully defined role in episodic memory. In this study, we utilized 1H magnetic resonance spectroscopy (MRS) and psychophysiological interaction (PPI) analysis to lend further support for the idea of a mnemonic role of the mPFC in humans. By using MRS, we measured mPFC γ-aminobutyric acid (GABA) and glutamate/glutamine (GLx) concentrations before and after volunteers memorized face-name association. We demonstrate that mPFC GLx but not GABA levels increased during the memory task, which appeared to be related to memory performance. Regarding functional connectivity, we used the subsequent memory paradigm and found that the GLx increase was associated with stronger mPFC connectivity to thalamus and hippocampus for associations subsequently recognized with high confidence as opposed to subsequently recognized with low confidence/forgotten. Taken together, we provide new evidence for an mPFC involvement in episodic memory by showing a memory-related increase in mPFC excitatory neurotransmitter levels that was associated with better memory and stronger memory-related functional connectivity in a medial prefrontal-thalamus-hippocampus network. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Individual memory change after anterior temporal lobectomy: a base rate analysis using regression-based outcome methodology.

PubMed

Martin, R C; Sawrie, S M; Roth, D L; Gilliam, F G; Faught, E; Morawetz, R B; Kuzniecky, R

1998-10-01

To characterize patterns of base rate change on measures of verbal and visual memory after anterior temporal lobectomy (ATL) using a newly developed regression-based outcome methodology that accounts for effects of practice and regression towards the mean, and to comment on the predictive utility of baseline memory measures on postoperative memory outcome. Memory change was operationalized using regression-based change norms in a group of left (n = 53) and right (n = 48) ATL patients. All patients were administered tests of episodic verbal (prose recall, list learning) and visual (figure reproduction) memory, and semantic memory before and after ATL. ATL patients displayed a wide range of memory outcome across verbal and visual memory domains. Significant performance declines were noted for 25-50% of left ATL patients on verbal semantic and episodic memory tasks, while one-third of right ATL patients displayed significant declines in immediate and delayed episodic prose recall. Significant performance improvement was noted in an additional one-third of right ATL patients on delayed prose recall. Base rate change was similar between the two ATL groups across immediate and delayed visual memory. Approximately one-fourth of all patients displayed clinically meaningful losses on the visual memory task following surgery. Robust relationships between preoperative memory measures and nonstandardized change scores were attenuated or reversed using standardized memory outcome techniques. Our results demonstrated substantial group variability in memory outcome for ATL patients. These results extend previous research by incorporating known effects of practice and regression to the mean when addressing meaningful neuropsychological change following epilepsy surgery. Our findings also suggest that future neuropsychological outcome studies should take steps towards controlling for regression-to-the-mean before drawing predictive conclusions.

Constructing realistic engrams: poststimulus activity of hippocampus and dorsal striatum predicts subsequent episodic memory.

PubMed

Ben-Yakov, Aya; Dudai, Yadin

2011-06-15

Encoding of real-life episodic memory commonly involves integration of information as the episode unfolds. Offline processing immediately following event offset is expected to play a role in encoding the episode into memory. In this study, we examined whether distinct human brain activity time-locked to the offset of short narrative audiovisual episodes could predict subsequent memory for the gist of the episodes. We found that a set of brain regions, most prominently the bilateral hippocampus and the bilateral caudate nucleus, exhibit memory-predictive activity time-locked to the stimulus offset. We propose that offline activity in these regions reflects registration to memory of integrated episodes.

Dynamics of the cognitive procedural learning in alcoholics with Korsakoff's syndrome.

PubMed

Beaunieux, Hélène; Pitel, Anne L; Witkowski, Thomas; Vabret, François; Viader, Fausto; Eustache, Francis

2013-06-01

While procedures acquired before the development of amnesia are likely to be preserved in alcoholic patients with Korsakoff's syndrome, the ability of Korsakoff patients (KS) to learn new cognitive procedures is called in question. According to the Adaptive Control of Thoughts model, learning a new cognitive procedure requires highly controlled processes in the initial cognitive phase, which may be difficult for KS with episodic and working memory deficits. The goals of the present study were to examine the learning dynamics of KS compared with uncomplicated alcoholic patients (AL) and control subjects (CS) and to determine the contribution of episodic and working memory abilities in cognitive procedural learning performance. Fourteen KS, 15 AL, and 15 CS were submitted to 40 trials (4 daily learning sessions) of the Tower of Toronto task (disk-transfer task similar to the tower of Hanoi task) as well as episodic and working memory tasks. The 10 KS who were able to perform the cognitive procedural learning task obtained lower results than both CS and AL. The cognitive phase was longer in the Korsakoff's syndrome group than in the other 2 groups but did not differ between the 3 groups any more when episodic memory abilities were controlled. Our results indicate that KS have impaired cognitive procedural learning abilities compared with both AL and CS. Episodic memory deficits observed in KS result in a delayed transition from the cognitive learning phase to more advanced learning phases and, as a consequence, in an absence of automation of the procedure within 40 trials. Copyright © 2012 by the Research Society on Alcoholism.

Behavioural and magnetoencephalographic evidence for the interaction between semantic and episodic memory in healthy elderly subjects.

PubMed

La Corte, Valentina; Dalla Barba, Gianfranco; Lemaréchal, Jean-Didier; Garnero, Line; George, Nathalie

2012-10-01

The relationship between episodic and semantic memory systems has long been debated. Some authors argue that episodic memory is contingent on semantic memory (Tulving 1984), while others postulate that both systems are independent since they can be selectively damaged (Squire 1987). The interaction between these memory systems is particularly important in the elderly, since the dissociation of episodic and semantic memory defects characterize different aging-related pathologies. Here, we investigated the interaction between semantic knowledge and episodic memory processes associated with faces in elderly subjects using an experimental paradigm where the semantic encoding of famous and unknown faces was compared to their episodic recognition. Results showed that the level of semantic awareness of items affected the recognition of those items in the episodic memory task. Event-related magnetic fields confirmed this interaction between episodic and semantic memory: ERFs related to the old/new effect during the episodic task were markedly different for famous and unknown faces. The old/new effect for famous faces involved sustained activities maximal over right temporal sensors, showing a spatio-temporal pattern partly similar to that found for famous versus unknown faces during the semantic task. By contrast, an old/new effect for unknown faces was observed on left parieto-occipital sensors. These findings suggest that the episodic memory for famous faces activated the retrieval of stored semantic information, whereas it was based on items' perceptual features for unknown faces. Overall, our results show that semantic information interfered markedly with episodic memory processes and suggested that the neural substrates of these two memory systems overlap.

Long-Term Cognitive Impairment in Kleine-Levin Syndrome

PubMed Central

Uguccioni, Ginevra; Lavault, Sophie; Chaumereuil, Charlotte; Golmard, Jean-Louis; Gagnon, Jean-François; Arnulf, Isabelle

2016-01-01

Study Objectives: In Kleine-Levin syndrome (KLS), episodes of hypersomnia, cognitive, and behavioral disturbances alternate with asymptomatic periods. Because 50% of patients report decreased academic performances, we evaluated their cognitive status during asymptomatic periods, determinants of deficits, and changes during follow-up. Methods: The cognitive assessment during asymptomatic periods in all consecutive patients with typical KLS and healthy controls included the non-verbal intelligence quotient (Raven Progressive Matrices), the Trail Making Test, the Stroop Color-Word Test, the Wechsler Memory Test, verbal fluencies, the Free and Cued Learning Memory Test, and the Rey-Osterreith Complex Figure. Cognitive status was reevaluated after 0.5 to 2 y in 44 patients. Results: At baseline, compared with the 42 controls, the 122 patients with KLS exhibited lower non-verbal intelligence quotient, speed of processing, attention, and reduced retrieval strategies in episodic memory. Higher episode frequency, shorter episode duration, shorter time since last episode, deeper sleep, and megaphagia during episodes predicted impaired memory. The visuoconstructional abilities and non-verbal memory were intact. After a mean follow-up of 1.7 ± 1.0 y, the episode frequency decreased from 4.6 ± 4.8 to 1.7 ± 1.9/y. The logical reasoning and attention improved, the processing speed remained low, and the retrieval strategies in verbal memory further worsened. Conclusions: In this field study, one-third of patients with KLS have long-term cognitive deficits affecting retrieval and processing speed. Cognitive function should be systematically tested in patients with KLS, which appears important to help patients in their academic studies. Citation: Uguccioni G, Lavault S, Chaumereuil C, Golmard JL, Gagnon JF, Arnulf I. Long-term cognitive impairment in kleine-levin syndrome. SLEEP 2016;39(2):429–438. PMID:26414895

Enhancing memory and imagination improves problem solving among individuals with depression.

PubMed

McFarland, Craig P; Primosch, Mark; Maxson, Chelsey M; Stewart, Brandon T

2017-08-01

Recent work has revealed links between memory, imagination, and problem solving, and suggests that increasing access to detailed memories can lead to improved imagination and problem-solving performance. Depression is often associated with overgeneral memory and imagination, along with problem-solving deficits. In this study, we tested the hypothesis that an interview designed to elicit detailed recollections would enhance imagination and problem solving among both depressed and nondepressed participants. In a within-subjects design, participants completed a control interview or an episodic specificity induction prior to completing memory, imagination, and problem-solving tasks. Results revealed that compared to the control interview, the episodic specificity induction fostered increased detail generation in memory and imagination and more relevant steps on the problem-solving task among depressed and nondepressed participants. This study builds on previous work by demonstrating that a brief interview can enhance problem solving among individuals with depression and supports the notion that episodic memory plays a key role in problem solving. It should be noted, however, that the results of the interview are relatively short-lived.

Everyday memory impairment in patients with temporal lobe epilepsy caused by hippocampal sclerosis.

PubMed

Rzezak, Patrícia; Lima, Ellen Marise; Gargaro, Ana Carolina; Coimbra, Erica; de Vincentiis, Silvia; Velasco, Tonicarlo Rodrigues; Leite, João Pereira; Busatto, Geraldo F; Valente, Kette D

2017-04-01

Patients with temporal lobe epilepsy caused by hippocampal sclerosis (TLE-HS) have episodic memory impairment. Memory has rarely been evaluated using an ecologic measure, even though performance on these tests is more related to patients' memory complaints. We aimed to measure everyday memory of patients with TLE-HS to age- and gender-matched controls. We evaluated 31 patients with TLE-HS and 34 healthy controls, without epilepsy and psychiatric disorders, using the Rivermead Behavioral Memory Test (RBMT), Visual Reproduction (WMS-III) and Logical Memory (WMS-III). We evaluated the impact of clinical variables such as the age of onset, epilepsy duration, AED use, history of status epilepticus, and seizure frequency on everyday memory. Statistical analyses were performed using MANCOVA with years of education as a confounding factor. Patients showed worse performance than controls on traditional memory tests and in the overall score of RBMT. Patients had more difficulties to recall names, a hidden belonging, to deliver a message, object recognition, to remember a story full of details, a previously presented short route, and in time and space orientation. Clinical epilepsy variables were not associated with RBMT performance. Memory span and working memory were correlated with worse performance on RBMT. Patients with TLE-HS demonstrated deficits in everyday memory functions. A standard neuropsychological battery, designed to assess episodic memory, would not evaluate these impairments. Impairment in recalling names, routes, stories, messages, and space/time disorientation can adversely impact social adaptation, and we must consider these ecologic measures with greater attention in the neuropsychological evaluation of patients with memory complaints. Copyright © 2017 Elsevier Inc. All rights reserved.

The reduction of adult neurogenesis in depression impairs the retrieval of new as well as remote episodic memory

PubMed Central

Fang, Jing; Demic, Selver; Cheng, Sen

2018-01-01

Major depressive disorder (MDD) is associated with an impairment of episodic memory, but the mechanisms underlying this deficit remain unclear. Animal models of MDD find impaired adult neurogenesis (AN) in the dentate gyrus (DG), and AN in DG has been suggested to play a critical role in reducing the interference between overlapping memories through pattern separation. Here, we study the effect of reduced AN in MDD on the accuracy of episodic memory using computational modeling. We focus on how memory is affected when periods with a normal rate of AN (asymptomatic states) alternate with periods with a low rate (depressive episodes), which has never been studied before. Also, unlike previous models of adult neurogenesis, which consider memories as static patterns, we model episodic memory as sequences of neural activity patterns. In our model, AN adds additional random components to the memory patterns, which results in the decorrelation of similar patterns. Consistent with previous studies, higher rates of AN lead to higher memory accuracy in our model, which implies that memories stored in the depressive state are impaired. Intriguingly, our model makes the novel prediction that memories stored in an earlier asymptomatic state are also impaired by a later depressive episode. This retrograde effect exacerbates with increased duration of the depressive episode. Finally, pattern separation at the sensory processing stage does not improve, but rather worsens, the accuracy of episodic memory retrieval, suggesting an explanation for why AN is found in brain areas serving memory rather than sensory function. In conclusion, while cognitive retrieval biases might contribute to episodic memory deficits in MDD, our model suggests a mechanistic explanation that affects all episodic memories, regardless of emotional relevance. PMID:29879169

The reduction of adult neurogenesis in depression impairs the retrieval of new as well as remote episodic memory.

PubMed

Fang, Jing; Demic, Selver; Cheng, Sen

2018-01-01

Major depressive disorder (MDD) is associated with an impairment of episodic memory, but the mechanisms underlying this deficit remain unclear. Animal models of MDD find impaired adult neurogenesis (AN) in the dentate gyrus (DG), and AN in DG has been suggested to play a critical role in reducing the interference between overlapping memories through pattern separation. Here, we study the effect of reduced AN in MDD on the accuracy of episodic memory using computational modeling. We focus on how memory is affected when periods with a normal rate of AN (asymptomatic states) alternate with periods with a low rate (depressive episodes), which has never been studied before. Also, unlike previous models of adult neurogenesis, which consider memories as static patterns, we model episodic memory as sequences of neural activity patterns. In our model, AN adds additional random components to the memory patterns, which results in the decorrelation of similar patterns. Consistent with previous studies, higher rates of AN lead to higher memory accuracy in our model, which implies that memories stored in the depressive state are impaired. Intriguingly, our model makes the novel prediction that memories stored in an earlier asymptomatic state are also impaired by a later depressive episode. This retrograde effect exacerbates with increased duration of the depressive episode. Finally, pattern separation at the sensory processing stage does not improve, but rather worsens, the accuracy of episodic memory retrieval, suggesting an explanation for why AN is found in brain areas serving memory rather than sensory function. In conclusion, while cognitive retrieval biases might contribute to episodic memory deficits in MDD, our model suggests a mechanistic explanation that affects all episodic memories, regardless of emotional relevance.

Neural correlates of episodic and semantic memory retrieval in borderline personality disorder: an fMRI study.

PubMed

Mensebach, Christoph; Beblo, Thomas; Driessen, Martin; Wingenfeld, Katja; Mertens, Markus; Rullkoetter, Nina; Lange, Wolfgang; Markowitsch, Hans J; Ollech, Isabella; Saveedra, Anamaria Silva; Rau, Harald; Woermann, Friedrich G

2009-02-28

Verbal memory impairment in borderline personality disorder (BPD) is still a matter of debate. In this study we combine investigations of both, memory retrieval as well as underlying neural circuits in BPD. Functional magnetic resonance imaging (fMRI) was used to study regional brain activation in 18 right-handed female patients with BPD and 18 matched controls during the retrieval of an episodic memory retrieval (EMR) task (free recall of a word list) and a semantic memory retrieval (SMR) task (verbal fluency). Despite unaffected performance in EMR and SMR, patients with BPD showed task-specific increased activation compared with controls. During EMR, the increased activation encompassed the posterior cingulate cortex bilaterally, the left middle and superior temporal gyrus, the right inferior frontal gyrus, and the right angular gyrus. SMR was associated with increased activation of the posterior cingulate cortex, of the right fusiform gyrus, of the left anterior cingulate cortex, and of the left postcentral gyrus. Our findings suggest that BPD patients may need to engage larger brain areas to reach a level of performance in episodic and semantic retrieval tasks that is comparable to that of healthy controls.

Episodic Memories in Anxiety Disorders: Clinical Implications

PubMed Central

Zlomuzica, Armin; Dere, Dorothea; Machulska, Alla; Adolph, Dirk; Dere, Ekrem; Margraf, Jürgen

2014-01-01

The aim of this review is to summarize research on the emerging role of episodic memories in the context of anxiety disorders (AD). The available literature on explicit, autobiographical, and episodic memory function in AD including neuroimaging studies is critically discussed. We describe the methodological diversity of episodic memory research in AD and discuss the need for novel tests to measure episodic memory in a clinical setting. We argue that alterations in episodic memory functions might contribute to the etiology of AD. We further explain why future research on the interplay between episodic memory function and emotional disorders as well as its neuroanatomical foundations offers the promise to increase the effectiveness of modern psychological treatments. We conclude that one major task is to develop methods and training programs that might help patients suffering from AD to better understand, interpret, and possibly actively use their episodic memories in a way that would support therapeutic interventions and counteract the occurrence of symptoms. PMID:24795583

Neural Changes Underlying the Development of Episodic Memory During Middle Childhood

PubMed Central

Ghetti, Simona; Bunge, Silvia A.

2012-01-01

Episodic memory is central to the human experience. In typically developing children, episodic memory improves rapidly during middle childhood. While the developmental cognitive neuroscience of episodic memory remains largely uncharted, recent research has begun to provide important insights. It has long been assumed that hippocampus-dependent binding mechanisms are in place by early childhood, and that improvements in episodic memory observed during middle childhood result from the protracted development of the prefrontal cortex. We revisit the notion that binding mechanisms are age-invariant, and propose that changes in the hippocampus and its projections to cortical regions also contribute to the development of episodic memory. We further review the role of developmental changes in lateral prefrontal and parietal cortices in this development. Finally, we discuss changes in white matter tracts connecting brain regions that are critical for episodic memory. Overall, we argue that changes in episodic memory emerge from the concerted effort of a network of relevant brain structures. PMID:22770728

Effects on incidental memory of affective tone in associated past and future episodes: influence of emotional intelligence.

PubMed

Toyota, Hiroshi

2011-02-01

The present study examined the effects of emotion elicited by episodes (past events or expected future events) and the relationship between individual differences in emotional intelligence and memory. Participants' emotional intelligence was assessed on the Japanese version of Emotional Skills and Competence Questionnaire. They rated the pleasantness of episodes they associated with targets, and then performed unexpected free recall tests. When the targets were associated with episodes that were past events, all participants recalled more of the targets associated with pleasant and unpleasant episodes than those associated with neutral episodes. However, when the targets were associated with episodes expected to occur in the future, only participants with higher emotional intelligence scores recalled more of the targets associated with pleasant and unpleasant episodes. The participants with lower emotional intelligence scores recalled the three target types with similar accuracy. These results were interpreted as showing that emotional intelligence is associated with the processing of targets associated with future episodes as retrieval cues.

Autobiographical and episodic memory deficits in mild traumatic brain injury.

PubMed

Wammes, Jeffrey D; Good, Tyler J; Fernandes, Myra A

2017-02-01

Those who have suffered a concussion, otherwise known as a mild traumatic brain injury (mTBI), often complain of lingering memory problems. However, there is little evidence in the behavioral literature reliably demonstrating memory deficits. Thus, in the present study, cognitive profiles including measures of general executive functioning and processing speed, as well as episodic and semantic memory were collected in younger and older adult participants with or without a remote (>1year prior to testing) mTBI. We first investigated whether there were observable episodic and autobiographical memory impairments associated with mTBI within an otherwise healthy young group. Next, because previous work had demonstrated some overlap in patterns of behavioral impairment in normally aging adults and younger adults with a history of mTBI (e.g. Ozen, Fernandes, Clark, & Roy, 2015), we sought to determine whether these groups displayed similar cognitive profiles. Lastly, we conducted an exploratory analysis to test whether having suffered an mTBI might exacerbate age-related cognitive decline. Results showed the expected age-related decline in episodic memory performance, coupled with a relative preservation of semantic memory in older adults. Importantly, this pattern was also present in younger adults with a history of remote mTBI. No differences were observed across older adult groups based on mTBI status. Logistic regression analyses, using each measure in our battery as a predictor, successfully classified mTBI status in younger participants with a high degree of specificity (79.5%). These results indicate that those who have had an mTBI demonstrate a distinct cognitive signature, characterized by impairment in episodic and autobiographical memory, coupled with a relative preservation of semantic memory. Copyright © 2016 Elsevier Inc. All rights reserved.

Preparation breeds success: Brain activity predicts remembering.

PubMed

Herron, Jane E; Evans, Lisa H

2018-05-09

Successful retrieval of episodic information is thought to involve the adoption of memory states that ensure that stimulus events are treated as episodic memory cues (retrieval mode) and which can bias retrieval toward specific memory contents (retrieval orientation). The neural correlates of these memory states have been identified in many neuroimaging studies, yet critically there is no direct evidence that they facilitate retrieval success. We cued participants before each test item to prepare to complete an episodic (retrieve the encoding task performed on the item at study) or a non-episodic task. Our design allowed us to separate event-related potentials (ERPs) elicited by the preparatory episodic cue according to the accuracy of the subsequent memory judgment. We predicted that a correlate of retrieval orientation should be larger in magnitude preceding correct source judgments than that preceding source errors. This hypothesis was confirmed. Preparatory ERPs at bilateral frontal sites were significantly more positive-going when preceding correct source judgments than when preceding source errors or correct responses in a non-episodic baseline task. Furthermore this effect was not evident prior to recognized items associated with incorrect source judgments. This pattern of results indicates a direct contribution of retrieval orientation to the recovery of task-relevant information and highlights the value of separating preparatory neural activity at retrieval according to subsequent memory accuracy. Moreover, at a more general level this work demonstrates the important role of pre-stimulus processing in ecphory, which has remained largely neglected to date. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Reduction in Delay Discounting by Using Episodic Future Imagination and the Association with Episodic Memory Capacity

PubMed Central

Hu, Xiaochen; Kleinschmidt, Helena; Martin, Jason A.; Han, Ying; Thelen, Manuela; Meiberth, Dix; Jessen, Frank; Weber, Bernd

2017-01-01

Delay discounting (DD) refers to the phenomenon that individuals discount future consequences. Previous studies showed that future imagination reduces DD, which was mediated by functional connectivity between medial prefrontal valuation areas and a key region for episodic memory (hippocampus). Future imagination involves an initial period of construction and a later period of elaboration, with the more elaborative latter period recruiting more cortical regions. This study examined whether elaborative future imagination modulated DD, and if so, what are the underlying neural substrates. It was assumed that cortical areas contribute to the modulation effect during the later period of imagination. Since future imagination is supported by episodic memory capacity, we additionally hypothesize that the neural network underlying the modulation effect is related to individual episodic memory capacity. Twenty-two subjects received an extensive interview on personal future events, followed by an fMRI DD experiment with and without the need to perform elaborative future imagination simultaneously. Subjects' episodic memory capacity was also assessed. Behavioral results replicate previous findings of a reduced discount rate in the DD plus imagination condition compared to the DD only condition. The behavioral effect positively correlated with: (i) subjective value signal changes in midline brain structures during the initial imagination period; and (ii) signal changes in left prefrontoparietal areas during the later imagination period. Generalized psychophysiological interaction (gPPI) analyses reveal positive correlations between the behavioral effect and functional connectivity among the following areas: right anterior cingulate cortex (ACC) and left hippocampus; left inferior parietal cortex (IPC) and left hippocampus; and left IPC and bilateral occipital cortices. These changes in functional connectivity are also associated with episodic memory capacity. A hierarchical multiple regression indicates that the model with both the valuation related signal changes in the right ACC and the imagination related signal changes in the left IPC best predicts the reduction in DD. This study illustrates interactions between the left hippocampus and multiple cortical regions underlying the modulation effect of elaborative episodic future imagination, demonstrating, for the first time, empirical support for a relation to individual episodic memory capacity. PMID:28105009

A Reduction in Delay Discounting by Using Episodic Future Imagination and the Association with Episodic Memory Capacity.

PubMed

Hu, Xiaochen; Kleinschmidt, Helena; Martin, Jason A; Han, Ying; Thelen, Manuela; Meiberth, Dix; Jessen, Frank; Weber, Bernd

2016-01-01

Delay discounting (DD) refers to the phenomenon that individuals discount future consequences. Previous studies showed that future imagination reduces DD, which was mediated by functional connectivity between medial prefrontal valuation areas and a key region for episodic memory (hippocampus). Future imagination involves an initial period of construction and a later period of elaboration, with the more elaborative latter period recruiting more cortical regions. This study examined whether elaborative future imagination modulated DD, and if so, what are the underlying neural substrates. It was assumed that cortical areas contribute to the modulation effect during the later period of imagination. Since future imagination is supported by episodic memory capacity, we additionally hypothesize that the neural network underlying the modulation effect is related to individual episodic memory capacity. Twenty-two subjects received an extensive interview on personal future events, followed by an fMRI DD experiment with and without the need to perform elaborative future imagination simultaneously. Subjects' episodic memory capacity was also assessed. Behavioral results replicate previous findings of a reduced discount rate in the DD plus imagination condition compared to the DD only condition. The behavioral effect positively correlated with: (i) subjective value signal changes in midline brain structures during the initial imagination period; and (ii) signal changes in left prefrontoparietal areas during the later imagination period. Generalized psychophysiological interaction (gPPI) analyses reveal positive correlations between the behavioral effect and functional connectivity among the following areas: right anterior cingulate cortex (ACC) and left hippocampus; left inferior parietal cortex (IPC) and left hippocampus; and left IPC and bilateral occipital cortices. These changes in functional connectivity are also associated with episodic memory capacity. A hierarchical multiple regression indicates that the model with both the valuation related signal changes in the right ACC and the imagination related signal changes in the left IPC best predicts the reduction in DD. This study illustrates interactions between the left hippocampus and multiple cortical regions underlying the modulation effect of elaborative episodic future imagination, demonstrating, for the first time, empirical support for a relation to individual episodic memory capacity.

Plastic modulation of episodic memory networks in the aging brain with cognitive decline.

PubMed

Bai, Feng; Yuan, Yonggui; Yu, Hui; Zhang, Zhijun

2016-07-15

Social-cognitive processing has been posited to underlie general functions such as episodic memory. Episodic memory impairment is a recognized hallmark of amnestic mild cognitive impairment (aMCI) who is at a high risk for dementia. Three canonical networks, self-referential processing, executive control processing and salience processing, have distinct roles in episodic memory retrieval processing. It remains unclear whether and how these sub-networks of the episodic memory retrieval system would be affected in aMCI. This task-state fMRI study constructed systems-level episodic memory retrieval sub-networks in 28 aMCI and 23 controls using two computational approaches: a multiple region-of-interest based approach and a voxel-level functional connectivity-based approach, respectively. These approaches produced the remarkably similar findings that the self-referential processing network made critical contributions to episodic memory retrieval in aMCI. More conspicuous alterations in self-referential processing of the episodic memory retrieval network were identified in aMCI. In order to complete a given episodic memory retrieval task, increases in cooperation between the self-referential processing network and other sub-networks were mobilized in aMCI. Self-referential processing mediate the cooperation of the episodic memory retrieval sub-networks as it may help to achieve neural plasticity and may contribute to the prevention and treatment of dementia. Copyright © 2016 Elsevier B.V. All rights reserved.

The effect of functional hearing loss and age on long- and short-term visuospatial memory: evidence from the UK biobank resource.

PubMed

Rönnberg, Jerker; Hygge, Staffan; Keidser, Gitte; Rudner, Mary

2014-01-01

The UK Biobank offers cross-sectional epidemiological data collected on >500,000 individuals in the UK between 40 and 70 years of age. Using the UK Biobank data, the aim of this study was to investigate the effects of functional hearing loss and hearing aid usage on visuospatial memory function. This selection of variables resulted in a sub-sample of 138,098 participants after discarding extreme values. A digit triplets functional hearing test was used to divide the participants into three groups: poor, insufficient and normal hearers. We found negative relationships between functional hearing loss and both visuospatial working memory (i.e., a card pair matching task) and visuospatial, episodic long-term memory (i.e., a prospective memory task), with the strongest association for episodic long-term memory. The use of hearing aids showed a small positive effect for working memory performance for the poor hearers, but did not have any influence on episodic long-term memory. Age also showed strong main effects for both memory tasks and interacted with gender and education for the long-term memory task. Broader theoretical implications based on a memory systems approach will be discussed and compared to theoretical alternatives.

Autobiographically significant concepts: more episodic than semantic in nature? An electrophysiological investigation of overlapping types of memory.

PubMed

Renoult, Louis; Davidson, Patrick S R; Schmitz, Erika; Park, Lillian; Campbell, Kenneth; Moscovitch, Morris; Levine, Brian

2015-01-01

A common assertion is that semantic memory emerges from episodic memory, shedding the distinctive contexts associated with episodes over time and/or repeated instances. Some semantic concepts, however, may retain their episodic origins or acquire episodic information during life experiences. The current study examined this hypothesis by investigating the ERP correlates of autobiographically significant (AS) concepts, that is, semantic concepts that are associated with vivid episodic memories. We inferred the contribution of semantic and episodic memory to AS concepts using the amplitudes of the N400 and late positive component, respectively. We compared famous names that easily brought to mind episodic memories (high AS names) against equally famous names that did not bring such recollections to mind (low AS names) on a semantic task (fame judgment) and an episodic task (recognition memory). Compared with low AS names, high AS names were associated with increased amplitude of the late positive component in both tasks. Moreover, in the recognition task, this effect of AS was highly correlated with recognition confidence. In contrast, the N400 component did not differentiate the high versus low AS names but, instead, was related to the amount of general knowledge participants had regarding each name. These results suggest that semantic concepts high in AS, such as famous names, have an episodic component and are associated with similar brain processes to those that are engaged by episodic memory. Studying AS concepts may provide unique insights into how episodic and semantic memory interact.

Differential association of left and right hippocampal volumes with verbal episodic and spatial memory in older adults.

PubMed

Ezzati, Ali; Katz, Mindy J; Zammit, Andrea R; Lipton, Michael L; Zimmerman, Molly E; Sliwinski, Martin J; Lipton, Richard B

2016-12-01

The hippocampus plays a critical role in verbal and spatial memory, thus any pathological damage to this formation may lead to cognitive impairment. It is suggested that right and left hippocampi are affected differentially in healthy or pathologic aging. The purpose of this study was to test the hypothesis that verbal episodic memory performance is associated with left hippocampal volume (HV) while spatial memory is associated with right HV. 115 non-demented adults over age 70 were drawn from the Einstein Aging Study. Verbal memory was measured using the free recall score from the Free and Cued Selective Reminding Test - immediate recall (FCSRT-IR), logical memory immediate and delayed subtests (LM-I and LM-II) from the Wechsler Memory Scale-Revised (WMS-R). Spatial Memory was measured using a computerized dot memory paradigm that has been validated for use in older adults. All participants underwent 3T MRI with subsequent automatized measurement of the volume of each hippocampus. The sample had a mean age of 78.7 years (SD=5.0); 57% were women, and 52% were white. Participants had a mean of 14.3 years (SD=3.5) of education. In regression models, two tests of verbal memory (FCSRT-IR free recall and LM-II) were positively associated with left HV, but not with right HV. Performance on the spatial memory task was associated with right HV, but not left HV. Our findings support the hypothesis that the left hippocampus plays a critical role in episodic verbal memory, while right hippocampus might be more important for spatial memory processing among non-demented older adults. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hippocampal activation during retrieval of spatial context from episodic and semantic memory.

PubMed

Hoscheidt, Siobhan M; Nadel, Lynn; Payne, Jessica; Ryan, Lee

2010-10-15

The hippocampus, a region implicated in the processing of spatial information and episodic memory, is central to the debate concerning the relationship between episodic and semantic memory. Studies of medial temporal lobe amnesic patients provide evidence that the hippocampus is critical for the retrieval of episodic but not semantic memory. On the other hand, recent neuroimaging studies of intact individuals report hippocampal activation during retrieval of both autobiographical memories and semantic information that includes historical facts, famous faces, and categorical information, suggesting that episodic and semantic memory may engage the hippocampus during memory retrieval in similar ways. Few studies have matched episodic and semantic tasks for the degree to which they include spatial content, even though spatial content may be what drives hippocampal activation during semantic retrieval. To examine this issue, we conducted a functional magnetic resonance imaging (fMRI) study in which retrieval of spatial and nonspatial information was compared during an episodic and semantic recognition task. Results show that the hippocampus (1) participates preferentially in the retrieval of episodic memories; (2) is also engaged by retrieval of semantic memories, particularly those that include spatial information. These data suggest that sharp dissociations between episodic and semantic memory may be overly simplistic and that the hippocampus plays a role in the retrieval of spatial content whether drawn from a memory of one's own life experiences or real-world semantic knowledge. Published by Elsevier B.V.

The Role of Aging in Intra-Item and Item-Context Binding Processes in Visual Working Memory

ERIC Educational Resources Information Center

Peterson, Dwight J.; Naveh-Benjamin, Moshe

2016-01-01

Aging is accompanied by declines in both working memory and long-term episodic memory processes. Specifically, important age-related memory deficits are characterized by performance impairments exhibited by older relative to younger adults when binding distinct components into a single integrated representation, despite relatively intact memory…

A Mathematical Model for the Hippocampus: Towards the Understanding of Episodic Memory and Imagination

NASA Astrophysics Data System (ADS)

Tsuda, I.; Yamaguti, Y.; Kuroda, S.; Fukushima, Y.; Tsukada, M.

How does the brain encode episode? Based on the fact that the hippocampus is responsible for the formation of episodic memory, we have proposed a mathematical model for the hippocampus. Because episodic memory includes a time series of events, an underlying dynamics for the formation of episodic memory is considered to employ an association of memories. David Marr correctly pointed out in his theory of archecortex for a simple memory that the hippocampal CA3 is responsible for the formation of associative memories. However, a conventional mathematical model of associative memory simply guarantees a single association of memory unless a rule for an order of successive association of memories is given. The recent clinical studies in Maguire's group for the patients with the hippocampal lesion show that the patients cannot make a new story, because of the lack of ability of imagining new things. Both episodic memory and imagining things include various common characteristics: imagery, the sense of now, retrieval of semantic information, and narrative structures. Taking into account these findings, we propose a mathematical model of the hippocampus in order to understand the common mechanism of episodic memory and imagination.

Meta-analytic Review of Memory Impairment in Behavioral Variant Frontotemporal Dementia.

PubMed

Poos, Jackie M; Jiskoot, Lize C; Papma, Janne M; van Swieten, John C; van den Berg, Esther

2018-03-19

A meta-analysis of the extent, nature and pattern of memory performance in behavioral variant frontotemporal dementia (bvFTD). Multiple observational studies have challenged the relative sparing of memory in bvFTD as stated in the current diagnostic criteria. We performed a meta-analytic review covering the period 1967 to February 2017 of case-control studies on episodic memory in bvFTD versus control participants (16 studies, 383 patients, 603 control participants), and patients with bvFTD versus those with Alzheimer's disease (AD) (20 studies, 452 bvFTD, 874 AD). Differences between both verbal and non-verbal working memory, episodic memory learning and recall, and recognition memory were examined. Data were extracted from the papers and combined into a common metric measure of effect, Hedges' d. Patients with bvFTD show large deficits in memory performance compared to controls (Hedges' d -1.10; 95% confidence interval [CI] [-1.23, -0.95]), but perform significantly better than patients with AD (Hedges' d 0.85; 95% CI [0.69, 1.03]). Learning and recall tests differentiate best between patients with bvFTD and AD (p<.01). There is 37-62% overlap in test scores between the two groups. This study points to memory disorders in patients with bvFTD, with performance at an intermediate level between controls and patients with AD. This indicates that, instead of being an exclusion criterion for bvFTD diagnosis, memory deficits should be regarded as a potential integral part of the clinical spectrum. (JINS, 2018, 24, 1-13).

Episodic and Semantic Aspects of Memory for Prose.

ERIC Educational Resources Information Center

Dooling, D. James

This report describes research on Bartlett's theory of constructive memory. In experiment one, schematic retention is related to Tulving's distinction between episodic and semantic memory. With the passage of time, memory for prose reflects decreasing output from episodic memory and increasing output from semantic memory. In experiment two,…

Attention, memory, visuoconstructive, and executive task performance in adolescents with anxiety disorders: a case-control community study.

PubMed

Jarros, Rafaela Behs; Salum, Giovanni Abrahão; Silva, Cristiano Tschiedel Belem da; Toazza, Rudineia; Becker, Natália; Agranonik, Marilyn; Salles, Jerusa Fumagalli de; Manfro, Gisele Gus

2017-01-01

The aim of the present study was to assess children and adolescents with mild and severe anxiety disorders for their performance in attention, verbal episodic memory, working memory, visuoconstructive skills, executive functions, and cognitive global functioning and conduct comparative analyses with the performance of children free from anxiety disorders. Our sample comprised 68 children and adolescents aged 10 to 17 years (41 with current diagnoses of anxiety disorders and 27 controls) selected from a larger cross-sectional community sample of adolescents. Children and adolescents with anxiety disorders were categorized into two groups on the basis of anxiety severity (mild or severe). All participants underwent a neuropsychological assessment battery to evaluate attention, verbal episodic memory, working memory, visuoconstructive skills, and executive and cognitive functions. No differences were found in any neuropsychological tests, with the single exception that the group with mild anxiety had better performance on the Digit Span backward test compared to subjects with severe anxiety and to controls (p = 0.041; η2 = 0.11). Not only might anxiety disorders spare main cognitive functions during adolescence, they may even enhance certain working memory processes.

The effects of glucose ingestion and glucose regulation on memory performance in older adults with mild cognitive impairment.

PubMed

Riby, L M; Marriott, A; Bullock, R; Hancock, J; Smallwood, J; McLaughlin, J

2009-04-01

Previous research investigating the impact of glucose ingestion and/or improvements in glucose regulation has found selective cognitive facilitation on episodic memory tasks in successful ageing and dementia. The present study aimed to extend this research to mild cognitive impairment (MCI). In a repeated-measures design, 24 older adults with and 24 older adults without MCI performed a battery of memory and attention tasks after 25 g of glucose or a sweetness matched placebo. In addition, to assess the impact of individual differences in glucose regulation, blood glucose measurements were taken throughout the testing session. Consistent with previous research, cognitive facilitation was observed for episodic memory tasks only in both successful ageing and MCI. Older adults with MCI had a similar glucose regulatory response as controls but their fasting levels were elevated. Notably, higher levels of blood glucose were associated with impaired memory performance in both the glucose and placebo conditions. Importantly, both blood glucose and memory performance indices were significant predictors of MCI status. The utility of glucose supplementation and the use of glucose regulation as a biological marker are discussed in relation to these data.

Familiarity and recollection processes in patients with recent-onset schizophrenia and their unaffected parents.

PubMed

Lefèbvre, Andrée-Anne; Cellard, Caroline; Tremblay, Sébastien; Achim, Amélie; Rouleau, Nancie; Maziade, Michel; Roy, Marc-André

2010-01-30

Episodic memory deficits are present in patients with schizophrenia (SZ) and their unaffected relatives and could be considered as a cognitive indicator of genetic vulnerability to SZ. The present study, involving patients with SZ as well as their parents, used experimental tasks specifically designed to disentangle the contribution of familiarity and recollection processes to episodic memory. The performance of patients with SZ (n=26) and their unaffected parents (n=35) was compared with that of healthy control groups matched on socio-demographic variables (controls of patients, n=26; controls of parents, n=35) on two memory tasks assessing recollection and familiarity. The first task was designed to investigate item recognition and memory for item-spatial context associations whereas the second targeted item-item associations. The results revealed an overall episodic memory deficit in patients with SZ, encompassing both familiarity and recollection, while unaffected parents showed a dysfunction restricted to the recollection process. Our study highlights differences and similarities in the source of the episodic memory deficit found in patients with SZ and their unaffected parents, and it suggests that recollection could act as a cognitive endophenotype of SZ. The results also suggest that use of experimental tasks represents a promising method in the search of cognitive endophenotypes in SZ.

Episode-Centered Guidelines for Teacher Belief Change toward Technology Integration

ERIC Educational Resources Information Center

Er, Erkan; Kim, ChanMin

2017-01-01

Teachers' episodic memories influence their beliefs. The investigation of episodic memories can help identify the teacher beliefs that limit technology-integration. We propose the Episode-Centered Belief Change (ECBC) model that utilizes teachers' episodic memories for changing beliefs impeding effective technology integration. We also propose…

Modulation of memory and visuospatial processes by biperiden and rivastigmine in elderly healthy subjects.

PubMed

Wezenberg, E; Verkes, R J; Sabbe, B G C; Ruigt, G S F; Hulstijn, W

2005-09-01

The central cholinergic system is implicated in cognitive functioning. The dysfunction of this system is expressed in many diseases like Alzheimer's disease, dementia of Lewy body, Parkinson's disease and vascular dementia. In recent animal studies, it was found that selective cholinergic modulation affects visuospatial processes even more than memory function. In the current study, we tried to replicate those findings. In order to investigate the acute effects of cholinergic drugs on memory and visuospatial functions, a selective anticholinergic drug, biperiden, was compared to a selective acetylcholinesterase-inhibiting drug, rivastigmine, in healthy elderly subjects. A double-blind, placebo-controlled, randomised, cross-over study was performed in 16 healthy, elderly volunteers (eight men, eight women; mean age 66.1, SD 4.46 years). All subjects received biperiden (2 mg), rivastigmine (3 mg) and placebo with an interval of 7 days between them. Testing took place 1 h after drug intake (which was around Tmax for both drugs). Subjects were presented with tests for episodic memory (wordlist and picture memory), working memory tasks (N-back, symbol recall) and motor learning (maze task, pursuit rotor). Visuospatial abilities were assessed by tests with high visual scanning components (tangled lines and Symbol Digit Substitution Test). Episodic memory was impaired by biperiden. Rivastigmine impaired recognition parts of the episodic memory performance. Working memory was non-significantly impaired by biperiden and not affected by rivastigmine. Motor learning as well as visuospatial processes were impaired by biperiden and improved by rivastigmine. These results implicate acetylcholine as a modulator not only of memory but also of visuospatial abilities.

Hemispheric encoding/retrieval asymmetry in episodic memory: positron emission tomography findings.

PubMed Central

Tulving, E; Kapur, S; Craik, F I; Moscovitch, M; Houle, S

1994-01-01

Data are reviewed from positron emission tomography studies of encoding and retrieval processes in episodic memory. These data suggest a hemispheric encoding/retrieval asymmetry model of prefrontal involvement in encoding and retrieval of episodic memory. According to this model, the left and right prefrontal lobes are part of an extensive neuronal network that subserves episodic remembering, but the two prefrontal hemispheres play different roles. Left prefrontal cortical regions are differentially more involved in retrieval of information from semantic memory and in simultaneously encoding novel aspects of the retrieved information into episodic memory. Right prefrontal cortical regions, on the other hand, are differentially more involved in episodic memory retrieval. PMID:8134342

Information Warfare: Evaluation of Operator Information Processing Models

DTIC Science & Technology

1997-10-01

that people can describe or report, including both episodic and semantic information. Declarative memory contains a network of knowledge represented...second dimension corresponds roughly to the distinction between episodic and semantic memory that is commonly made in cognitive psychology. Episodic ...3 is long-term memory for the discourse, a subset of episodic memory . Partition 4 is long-term semantic memory , or the knowledge-base. According to

Interdependence of episodic and semantic memory: evidence from neuropsychology.

PubMed

Greenberg, Daniel L; Verfaellie, Mieke

2010-09-01

Tulving's (1972) theory of memory draws a distinction between general knowledge (semantic memory) and memory for events (episodic memory). Neuropsychological studies have generally examined each type of memory in isolation, but theorists have long argued that these two forms of memory are interdependent. Here we review several lines of neuropsychological research that have explored the interdependence of episodic and semantic memory. The studies show that these forms of memory can affect each other both at encoding and at retrieval. We suggest that theories of memory should be revised to account for all of the interdependencies between episodic and semantic memory; they should also incorporate forms of memory that do not fit neatly into either category.

Interdependence of episodic and semantic memory: Evidence from neuropsychology

PubMed Central

GREENBERG, DANIEL L.; VERFAELLIE, MIEKE

2010-01-01

Tulving's (1972) theory of memory draws a distinction between general knowledge (semantic memory) and memory for events (episodic memory). Neuropsychological studies have generally examined each type of memory in isolation, but theorists have long argued that these two forms of memory are interdependent. Here we review several lines of neuropsychological research that have explored the interdependence of episodic and semantic memory. The studies show that these forms of memory can affect each other both at encoding and at retrieval. We suggest that theories of memory should be revised to account for all of the interdependencies between episodic and semantic memory; they should also incorporate forms of memory that do not fit neatly into either category. PMID:20561378

The relationship of Theory of Mind with symptoms and cognitive impairment in bipolar disorder: a prospective study.

PubMed

Ioannidi, N; Konstantakopoulos, G; Sakkas, D; Oulis, P

2015-01-01

Previous studies in bipolar disorder suggest patients' deficient performance in Theory of Mind tasks, both during manic or depressive episodes and in remission. However, most of the extant studies were cross-sectional and did not control for potential confounders such as residual symptoms or co-existent deficits in other cognitive functions. The present study is the first prospective study that assessed the effect of remission on Theory of Mind (ToM) in patients with Bipolar Disorder (BD) controlling for other cognitive deficits. ToM was assessed in 29 patients with BD type I during an episode of the illness and in remission as well as in 29 healthy controls. The two groups were pair-matched for gender, age and education level. Three tests with different levels of complexity were used to assess ToM: First Order False Belief Task, Hinting Task and Faux Pas Recognition Test. Concomitantly, a comprehensive battery of neuropsychological tests was administered to all participants assessing general intelligence, working memory, attention, speed processing, verbal learning, and memory and executive functions. The Hamilton Rating Scale for Depression, Young Mania Rating Scale, Brief Psychiatric Rating Scale, and GAF were also administered to the patients. Differences between patients--in acute phase and in remission--and the control group on neuropsychological tests were tested using one-way ANOVA with post hoc Bonferroni corrections. The effect of other cognitive deficits on patients' ToM dysfunction was controlled for using general linear models. The patients showed significantly lower performance in all ToM tests during the acute phases as compared to the control group (p values from 0.001 to 0.014). However, these impairments did not persist beyond acute mood episode, except patients' poor performance on Faux Pas (p=0.001). Additionally, patients had poorer performance compared to control group in verbal learning and memory (p<0.001) as well as visuospatial working memory (p<0.001) during both the acute and the euthymic phases of the illness. Patients also had poorer performance than healthy controls in immediate memory (p=0.026) and executive functions (p=0.001), however only during episodes of illness. Differences in Faux Pas did not remain statistically significant when the effect of verbal memory and visuospatial working memory was controlled for. Differences in other ToM tests during episodes did not remain statistically significant, when other cognitive functions that were found impaired in patients during episodes, were controlled for. The findings of this study support the hypothesis that ToM dysfunction in BD is associated with mood symptoms and it might reflect underlying cognitive deficits rather than representing a specific trait marker of the disorder.

Developmental Differences in Relations between Episodic Memory and Hippocampal Subregion Volume during Early Childhood

ERIC Educational Resources Information Center

Riggins, Tracy; Blankenship, Sarah L.; Mulligan, Elizabeth; Rice, Katherine; Redcay, Elizabeth

2015-01-01

Episodic memory shows striking improvement during early childhood. However, neural contributions to these behavioral changes are not well understood. This study examined associations between episodic memory and volume of subregions (head, body, and tail) of the hippocampus--a structure known to support episodic memory in school-aged children and…

Episodic autobiographical memory is associated with variation in the size of hippocampal subregions.

PubMed

Palombo, Daniela J; Bacopulos, Agnes; Amaral, Robert S C; Olsen, Rosanna K; Todd, Rebecca M; Anderson, Adam K; Levine, Brian

2018-02-01

Striking individual differences exist in the human capacity to recollect past events, yet, little is known about the neural correlates of such individual differences. Studies investigating hippocampal volume in relation to individual differences in laboratory measures of episodic memory in young adults suggest that whole hippocampal volume is unrelated (or even negatively associated) with episodic memory. However, anatomical and functional specialization across hippocampal subregions suggests that individual differences in episodic memory may be linked to particular hippocampal subregions, as opposed to whole hippocampal volume. Given that the DG/CA 2/3 circuitry is thought to be especially critical for supporting episodic memory in humans, we predicted that the volume of this region would be associated with individual variability in episodic memory. This prediction was supported using high-resolution MRI of the hippocampal subfields and measures of real-world (autobiographical) episodic memory. In addition to the association with DG/CA 2/3 , we further observed a relationship between episodic autobiographical memory and subiculum volume, whereas no association was observed with CA 1 or with whole hippocampal volume. These findings provide insight into the possible neural substrates that mediate individual differences in real-world episodic remembering in humans. © 2017 Wiley Periodicals, Inc.

The Pivotal Role of Semantic Memory in Remembering the Past and Imagining the Future

PubMed Central

Irish, Muireann; Piguet, Olivier

2013-01-01

Episodic memory refers to a complex and multifaceted process which enables the retrieval of richly detailed evocative memories from the past. In contrast, semantic memory is conceptualized as the retrieval of general conceptual knowledge divested of a specific spatiotemporal context. The neural substrates of the episodic and semantic memory systems have been dissociated in healthy individuals during functional imaging studies, and in clinical cohorts, leading to the prevailing view that episodic and semantic memory represent functionally distinct systems subtended by discrete neurobiological substrates. Importantly, however, converging evidence focusing on widespread neural networks now points to significant overlap between those regions essential for retrieval of autobiographical memories, episodic learning, and semantic processing. Here we review recent advances in episodic memory research focusing on neurodegenerative populations which has proved revelatory for our understanding of the complex interplay between episodic and semantic memory. Whereas episodic memory research has traditionally focused on retrieval of autobiographical events from the past, we also include evidence from the recent paradigm shift in which episodic memory is viewed as an adaptive and constructive process which facilitates the imagining of possible events in the future. We examine the available evidence which converges to highlight the pivotal role of semantic memory in providing schemas and meaning whether one is engaged in autobiographical retrieval for the past, or indeed, is endeavoring to construct a plausible scenario of an event in the future. It therefore seems plausible to contend that semantic processing may underlie most, if not all, forms of episodic memory, irrespective of temporal condition. PMID:23565081

Neural activity in the medial temporal lobe reveals the fidelity of mental time travel.

PubMed

Kragel, James E; Morton, Neal W; Polyn, Sean M

2015-02-18

Neural circuitry in the medial temporal lobe (MTL) is critically involved in mental time travel, which involves the vivid retrieval of the details of past experience. Neuroscientific theories propose that the MTL supports memory of the past by retrieving previously encoded episodic information, as well as by reactivating a temporal code specifying the position of a particular event within an episode. However, the neural computations supporting these abilities are underspecified. To test hypotheses regarding the computational mechanisms supported by different MTL subregions during mental time travel, we developed a computational model that linked a blood oxygenation level-dependent signal to cognitive operations, allowing us to predict human performance in a memory search task. Activity in the posterior MTL, including parahippocampal cortex, reflected how strongly one reactivates the temporal context of a retrieved memory, allowing the model to predict whether the next memory will correspond to a nearby moment in the study episode. A signal in the anterior MTL, including perirhinal cortex, indicated the successful retrieval of list items, without providing information regarding temporal organization. A hippocampal signal reflected both processes, consistent with theories that this region binds item and context information together to form episodic memories. These findings provide evidence for modern theories that describe complementary roles of the hippocampus and surrounding parahippocampal and perirhinal cortices during the retrieval of episodic memories, shaping how humans revisit the past. Copyright © 2015 the authors 0270-6474/15/352914-13$15.00/0.

Impaired cue identification and intention retrieval underlie prospective memory deficits in patients with first-episode schizophrenia.

PubMed

Liu, Dengtang; Ji, Chengfeng; Zhuo, Kaiming; Song, Zhenhua; Wang, Yingchan; Mei, Li; Zhu, Dianming; Xiang, Qiong; Chen, Tianyi; Yang, Zhilei; Zhu, Guang; Wang, Ya; Cheung, Eric Fc; Xiang, Yu-Tao; Fan, Xiaoduo; Chan, Raymond Ck; Xu, Yifeng; Jiang, Kaida

2017-03-01

Schizophrenia is associated with impairment in prospective memory, the ability to remember to carry out an intended action in the future. It has been established that cue identification (detection of the cue event signaling that an intended action should be performed) and intention retrieval (retrieval of an intention from long-term memory following the recognition of a prospective cue) are two important processes underlying prospective memory. The purpose of this study was to examine prospective memory deficit and underlying cognitive processes in patients with first-episode schizophrenia. This study examined cue identification and intention retrieval components of event-based prospective memory using a dual-task paradigm in 30 patients with first-episode schizophrenia and 30 healthy controls. All participants were also administered a set of tests assessing working memory and retrospective memory. Both cue identification and intention retrieval were impaired in patients with first-episode schizophrenia compared with healthy controls ( ps < 0.05), with a large effect size for cue identification (Cohen's d = 0.98) and a medium effect size for intention retrieval (Cohen's d = 0.62). After controlling for working memory and retrospective memory, the difference in cue identification between patients and healthy controls remained significant. However, the difference in intention retrieval between the two groups was no longer significant. In addition, there was a significant inverse relationship between cue identification and negative symptoms ( r = -0.446, p = 0.013) in the patient group. These findings suggest that both cue identification and intention retrieval in event-based prospective memory are impaired in patients with first-episode schizophrenia. Cue identification and intention retrieval could be potentially used as biomarkers for early detection and treatment prognosis of schizophrenia. In addition, addressing cue identification deficit through cognitive enhancement training may potentially improve negative symptoms as well.

Insights from child development on the relationship between episodic and semantic memory.

PubMed

Robertson, Erin K; Köhler, Stefan

2007-11-05

The present study was motivated by a recent controversy in the neuropsychological literature on semantic dementia as to whether episodic encoding requires semantic processing or whether it can proceed solely based on perceptual processing. We addressed this issue by examining the effect of age-related limitations in semantic competency on episodic memory in 4-6-year-old children (n=67). We administered three different forced-choice recognition memory tests for pictures previously encountered in a single study episode. The tests varied in the degree to which access to semantically encoded information was required at retrieval. Semantic competency predicted recognition performance regardless of whether access to semantic information was required. A direct relation between picture naming at encoding and subsequent recognition was also found for all tests. Our findings emphasize the importance of semantic encoding processes even in retrieval situations that purportedly do not require access to semantic information. They also highlight the importance of testing neuropsychological models of memory in different populations, healthy and brain damaged, at both ends of the developmental continuum.

Visual associations cued recall A Paradigm for Measuring Episodic Memory Decline in Alzheimer's Disease.

PubMed

Meyer, Sascha R A; Spaan, Pauline E J; Boelaarts, Leo; Ponds, Rudolf W H M; Schmand, Ben; de Jonghe, Jos F M

2016-09-01

Repeated measurements of episodic memory are needed for monitoring amnestic mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD). Most episodic memory tests may pose a challenge to patients, even when they are in the milder stages of the disease. This cross-sectional study compared floor effects of the Visual Association Test (VAT) and the Rey Auditory Verbal Learning Test (RAVLT) in healthy elderly controls and in patients with aMCI or AD (N = 125). A hierarchical multiple regression analysis was used to examine whether linear or quadratic trends best fitted the data of cognitive test performance across global cognitive impairment. Results showed that VAT total scores decreased linearly across the range of global cognitive impairment, whereas RAVLT total scores showed a quadratic trend, with total scores levelling off for 90% of aMCI patients and 94% of AD patients. We conclude that the VAT shows few if any floor effects in patients with aMCI and mild AD and is therefore a potentially promising cognitive test for monitoring episodic memory impairment.

Intrusions in story recall: when over-learned information interferes with episodic memory recall. Evidence from Alzheimer's disease.

PubMed

De Anna, Francesca; Attali, Eve; Freynet, Laurence; Foubert, Lucie; Laurent, Aurore; Dubois, Bruno; Dalla Barba, Gianfranco

2008-03-01

Patients with Alzheimer's disease (AD) suffer from distortions of memory. Among such distortions, intrusions in memory tests are frequently observed. In this study we describe the performance of a group of mild AD patients and a group of normal controls on the recall of three different types of stories: a previously unknown story, a well-known fairy-tale (Cinderella), and a modified well-known fairy-tale (Little Red Riding Hood is not eaten by the wolf). The aim of our study was to test the hypothesis that in patients who tend to produce intrusions, over-learned information interferes with episodic recall, i.e., the retrieval of specific, unique past episodes. AD patients produced significantly more intrusions in the recall of the modified fairy-tale compared to the recall of the two other stories. Intrusions in the recall of the modified fairy-tale always consisted of elements of the original version of the story. We suggest that in AD patients intrusions may be traced back to the interference of strongly represented, over-learned information in episodic memory recall.

Cortical Thickness and Episodic Memory Impairment in Systemic Lupus Erythematosus.

PubMed

Bizzo, Bernardo Canedo; Sanchez, Tiago Arruda; Tukamoto, Gustavo; Zimmermann, Nicolle; Netto, Tania Maria; Gasparetto, Emerson Leandro

2017-01-01

The purpose of this study was to investigate differences in brain cortical thickness of systemic lupus erythematosus (SLE) patients with and without episodic memory impairment and healthy controls. We studied 51 patients divided in 2 groups (SLE with episodic memory deficit, n = 17; SLE without episodic memory deficit, n = 34) by the Rey Auditory Verbal Learning Test and 34 healthy controls. Groups were paired based on sex, age, education, Mini-Mental State Examination score, and accumulation of disease burden. Cortical thickness from magnetic resonance imaging scans was determined using the FreeSurfer software package. SLE patients with episodic memory deficits presented reduced cortical thickness in the left supramarginal cortex and superior temporal gyrus when compared to the control group and in the right superior frontal, caudal, and rostral middle frontal and precentral gyri when compared to the SLE group without episodic memory impairment considering time since diagnosis of SLE as covaried. There were no significant differences in the cortical thickness between the SLE without episodic memory and control groups. Different memory-related cortical regions thinning were found in the episodic memory deficit group when individually compared to the groups of patients without memory impairment and healthy controls. Copyright © 2016 by the American Society of Neuroimaging.

Memory systems in schizophrenia: Modularity is preserved but deficits are generalized.

PubMed

Haut, Kristen M; Karlsgodt, Katherine H; Bilder, Robert M; Congdon, Eliza; Freimer, Nelson B; London, Edythe D; Sabb, Fred W; Ventura, Joseph; Cannon, Tyrone D

2015-10-01

Schizophrenia patients exhibit impaired working and episodic memory, but this may represent generalized impairment across memory modalities or performance deficits restricted to particular memory systems in subgroups of patients. Furthermore, it is unclear whether deficits are unique from those associated with other disorders. Healthy controls (n=1101) and patients with schizophrenia (n=58), bipolar disorder (n=49) and attention-deficit-hyperactivity-disorder (n=46) performed 18 tasks addressing primarily verbal and spatial episodic and working memory. Effect sizes for group contrasts were compared across tasks and the consistency of subjects' distributional positions across memory domains was measured. Schizophrenia patients performed poorly relative to the other groups on every test. While low to moderate correlation was found between memory domains (r=.320), supporting modularity of these systems, there was limited agreement between measures regarding each individual's task performance (ICC=.292) and in identifying those individuals falling into the lowest quintile (kappa=0.259). A general ability factor accounted for nearly all of the group differences in performance and agreement across measures in classifying low performers. Pathophysiological processes involved in schizophrenia appear to act primarily on general abilities required in all tasks rather than on specific abilities within different memory domains and modalities. These effects represent a general shift in the overall distribution of general ability (i.e., each case functioning at a lower level than they would have if not for the illness), rather than presence of a generally low-performing subgroup of patients. There is little evidence that memory impairments in schizophrenia are shared with bipolar disorder and ADHD. Copyright © 2015 Elsevier B.V. All rights reserved.

Memory systems in schizophrenia: Modularity is preserved but deficits are generalized

PubMed Central

Haut, Kristen M.; Karlsgodt, Katherine H.; Bilder, Robert M.; Congdon, Eliza; Freimer, Nelson; London, Edythe D.; Sabb, Fred W.; Ventura, Joseph; Cannon, Tyrone D.

2015-01-01

Objective Schizophrenia patients exhibit impaired working and episodic memory, but this may represent generalized impairment across memory modalities or performance deficits restricted to particular memory systems in subgroups of patients. Furthermore, it is unclear whether deficits are unique from those associated with other disorders. Method Healthy controls (n=1101) and patients with schizophrenia (n=58), bipolar disorder (n=49) and attention-deficit-hyperactivity-disorder (n=46) performed 18 tasks addressing primarily verbal and spatial episodic and working memory. Effect sizes for group contrasts were compared across tasks and the consistency of subjects’ distributional positions across memory domains was measured. Results Schizophrenia patients performed poorly relative to the other groups on every test. While low to moderate correlation was found between memory domains (r=.320), supporting modularity of these systems, there was limited agreement between measures regarding each individual’s task performance (ICC=.292) and in identifying those individuals falling into the lowest quintile (kappa=0.259). A general ability factor accounted for nearly all of the group differences in performance and agreement across measures in classifying low performers. Conclusions Pathophysiological processes involved in schizophrenia appear to act primarily on general abilities required in all tasks rather than on specific abilities within different memory domains and modalities. These effects represent a general shift in the overall distribution of general ability (i.e., each case functioning at a lower level than they would have if not for the illness), rather than presence of a generally low-performing subgroup of patients. There is little evidence that memory impairments in schizophrenia are shared with bipolar disorder and ADHD. PMID:26299707

Mental reinstatement of encoding context improves episodic remembering.

PubMed

Bramão, Inês; Karlsson, Anna; Johansson, Mikael

2017-09-01

This study investigates context-dependent memory retrieval. Previous work has shown that physically re-experiencing the encoding context at retrieval improves memory accessibility. The current study examined if mental reconstruction of the original encoding context would yield parallel memory benefits. Participants performed a cued-recall memory task, preceded either by a mental or by a physical context reinstatement task, and we manipulated whether the context reinstated at retrieval overlapped with the context of the target episode. Both behavioral and electrophysiological measures of brain activity showed strong encoding-retrieval (E-R) overlap effects, with facilitated episodic retrieval when the encoding and retrieval contexts overlapped. The electrophysiological E-R overlap effect was more sustained and involved more posterior regions when context was mentally compared with physically reinstated. Additionally, a time-frequency analysis revealed that context reinstatement alone engenders recollection of the target episode. However, while recollection of the target memory is readily prompted by a physical reinstatement, target recollection during mental reinstatement is delayed and depends on the gradual reconstruction of the context. Taken together, our results show facilitated episodic remembering also when mentally reinstating the encoding context; and that such benefits are supported by both shared and partially non-overlapping neural mechanisms when the encoding context is mentally reconstructed as compared with physically presented at the time of retrieval. Copyright © 2017 Elsevier Ltd. All rights reserved.

SU30. Long-Term Memory Deficits in Schizophrenia: Are All Things Equal?

PubMed Central

Rossell, Susan

2017-01-01

Abstract Background: Kraepelin and Bleulernoted that patients with schizophrenia had significant cognitive deficits over a century ago; however, their observations with regard to long-term memory have not born out within empirical studies. They reported that episodic memory was intact but indicated that organization of memories, or semantic memory, was disordered. This study aimed to synthesize a century of research in the 2 long-term memory processes of episodic and semantic memory across the psychosis continuum: chronic patients, first-episode patients, high risk for psychosis cohorts, and persons with high schizotypy. Methods: A systematic review and meta-analysis was completed within the 2 domains of long-term memory across the psychosis continuum. Search terms included long-term memory, episodic, semantic, and derivations of these terms. The data were synthesized independently for episodic and semantic memory. Four independent populations were investigated: chronic patients, first-episode patients, high risk for psychosis cohorts, and persons with high schizotypy. Our approach followed the PRISMA guidelines. Thus, the pooled mean effect sizes are reported for 8 analyses. These effect sizes represent case cohort in comparison to a healthy control cohort. Results: The results were as follows, for episodic memory: chronic patients d = 1.12, first-episode patients d = 1.12, high risk d = 1.14, and high schizotypy d = 0.13. Thus, establishing that there is poor evidence of episodic memory deficits in persons with high schizotypy. For semantic memory, the literature showed a different pattern: chronic patients d = 1.2, first-episode patients d = 1.08, high risk d = 1.16, and high schizotypy d = 0.95. Thus, a consistent degree of semantic memory deficits across the continuum. Conclusion: The literature suggests a dissociated pattern of long-term memory deficits; whereby semantic memory abnormalities are more likely to be considered endophenotypes or cognitive markers for schizophrenia than episodic memory deficits. Differential patterns of semantic memory organization are argued to be present prior to the onset of the disorder. There is additional evidence to suggest that idiosyncratic storage of semantic material underlies the development of the usual beliefs and speech patterns present in the forms of delusions and formal thought disorder. Consequently, semantic memory might be a useful target for cognitive remediation.

Recognition memory, self-other source memory, and theory-of-mind in children with autism spectrum disorder.

PubMed

Lind, Sophie E; Bowler, Dermot M

2009-09-01

This study investigated semantic and episodic memory in autism spectrum disorder (ASD), using a task which assessed recognition and self-other source memory. Children with ASD showed undiminished recognition memory but significantly diminished source memory, relative to age- and verbal ability-matched comparison children. Both children with and without ASD showed an "enactment effect", demonstrating significantly better recognition and source memory for self-performed actions than other-person-performed actions. Within the comparison group, theory-of-mind (ToM) task performance was significantly correlated with source memory, specifically for other-person-performed actions (after statistically controlling for verbal ability). Within the ASD group, ToM task performance was not significantly correlated with source memory (after controlling for verbal ability). Possible explanations for these relations between source memory and ToM are considered.

Electrical Stimulation in Hippocampus and Entorhinal Cortex Impairs Spatial and Temporal Memory.

PubMed

Goyal, Abhinav; Miller, Jonathan; Watrous, Andrew J; Lee, Sang Ah; Coffey, Tom; Sperling, Michael R; Sharan, Ashwini; Worrell, Gregory; Berry, Brent; Lega, Bradley; Jobst, Barbara C; Davis, Kathryn A; Inman, Cory; Sheth, Sameer A; Wanda, Paul A; Ezzyat, Youssef; Das, Sandhitsu R; Stein, Joel; Gorniak, Richard; Jacobs, Joshua

2018-05-09

The medial temporal lobe (MTL) is widely implicated in supporting episodic memory and navigation, but its precise functional role in organizing memory across time and space remains elusive. Here we examine the specific cognitive processes implemented by MTL structures (hippocampus and entorhinal cortex) to organize memory by using electrical brain stimulation, leveraging its ability to establish causal links between brain regions and features of behavior. We studied neurosurgical patients of both sexes who performed spatial-navigation and verbal-episodic memory tasks while brain stimulation was applied in various regions during learning. During the verbal memory task, stimulation in the MTL disrupted the temporal organization of encoded memories such that items learned with stimulation tended to be recalled in a more randomized order. During the spatial task, MTL stimulation impaired subjects' abilities to remember items located far away from boundaries. These stimulation effects were specific to the MTL. Our findings thus provide the first causal demonstration in humans of the specific memory processes that are performed by the MTL to encode when and where events occurred. SIGNIFICANCE STATEMENT Numerous studies have implicated the medial temporal lobe (MTL) in encoding spatial and temporal memories, but they have not been able to causally demonstrate the nature of the cognitive processes by which this occurs in real-time. Electrical brain stimulation is able to demonstrate causal links between a brain region and a given function with high temporal precision. By examining behavior in a memory task as subjects received MTL stimulation, we provide the first causal evidence demonstrating the role of the MTL in organizing the spatial and temporal aspects of episodic memory. Copyright © 2018 the authors 0270-6474/18/384471-11$15.00/0.

Recall from Semantic and Episodic Memory.

ERIC Educational Resources Information Center

Gillund, Gary; Perlmutter, Marion

Although research in episodic recall memory, comparing younger and older adults, favors the younger adults, findings in semantic memory research are less consistent. To examine age differences in semantic and episodic memory recall, 72 young adults (mean age, 20.8) and 72 older adults (mean age 71) completed three memory tests under varied…

Development in the organization of episodic memories in middle childhood and adolescence.

PubMed

Chen, Yan; McAnally, Helena Margaret; Reese, Elaine

2013-01-01

The basic elements of autobiographical or episodic memory are established in early childhood, although the exact age at which memories gain episodic status is still under contention. The self-memory system proposed that adults use "lifetime periods" to group episodic memories together into chapters of the life story - an evolving and internalized account of significant life events that are self-defining. Two studies examined at what point in development children or adolescents begin to take advantage of lifetime-period chapters to organize their episodic memories. The results of Study 1 with 8- to 12-year-olds revealed that the ability to provide life story chapters began to emerge as early as 8 years of age. In Study 2 with adolescents aged 12-21, this ability continued to develop into late adolescence among New Zealand European (NZE) and New Zealand Chinese (NZC) adolescents; however, cultural differences also existed in the specificity of memories. NZC adolescents narrated fewer life story chapters containing specific memories than NZE adolescents. These findings support and extend current theories of episodic memory by specifying that pre-adolescents are starting to organize their episodic memories into lifetime periods, but this achievement is not fully realized until later in adolescence.

A review on the neural bases of episodic odor memory: from laboratory-based to autobiographical approaches

PubMed Central

Saive, Anne-Lise; Royet, Jean-Pierre; Plailly, Jane

2014-01-01

Odors are powerful cues that trigger episodic memories. However, in light of the amount of behavioral data describing the characteristics of episodic odor memory, the paucity of information available on the neural substrates of this function is startling. Furthermore, the diversity of experimental paradigms complicates the identification of a generic episodic odor memory network. We conduct a systematic review of the literature depicting the current state of the neural correlates of episodic odor memory in healthy humans by placing a focus on the experimental approaches. Functional neuroimaging data are introduced by a brief characterization of the memory processes investigated. We present and discuss laboratory-based approaches, such as odor recognition and odor associative memory, and autobiographical approaches, such as the evaluation of odor familiarity and odor-evoked autobiographical memory. We then suggest the development of new laboratory-ecological approaches allowing for the controlled encoding and retrieval of specific multidimensional events that could open up new prospects for the comprehension of episodic odor memory and its neural underpinnings. While large conceptual differences distinguish experimental approaches, the overview of the functional neuroimaging findings suggests relatively stable neural correlates of episodic odor memory. PMID:25071494

Episodic Memory Impairments in Primary Brain Tumor Patients.

PubMed

Durand, Thomas; Berzero, Giulia; Bompaire, Flavie; Hoffmann, Sabine; Léger, Isabelle; Jego, Virginie; Baruteau, Marie; Delgadillo, Daniel; Taillia, Hervé; Psimaras, Dimitri; Ricard, Damien

2018-01-04

Cognitive investigations in brain tumor patients have mostly explored episodic memory without differentiating between encoding, storage, and retrieval deficits. The aim of this study is to offer insight into the memory sub-processes affected in primary brain tumor patients and propose an appropriate assessment method. We retrospectively reviewed the clinical and memory assessments of 158 patients with primary brain tumors who had presented to our departments with cognitive complaints and were investigated using the Free and Cued Selective Reminding Test. Retrieval was the process of episodic memory most frequently affected, with deficits in this domain detected in 92% of patients with episodic memory impairments. Storage and encoding deficits were less prevalent, with impairments, respectively, detected in 41% and 23% of memory-impaired patients. The pattern of episodic memory impairment was similar across different tumor histologies and treatment modalities. Although all processes of episodic memory were found to be impaired, retrieval was by far the most widely affected function. A thorough assessment of all three components of episodic memory should be part of the regular neuropsychological evaluation in patients with primary brain tumors. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Reactivation of Reward-Related Patterns from Single Past Episodes Supports Memory-Based Decision Making.

PubMed

Wimmer, G Elliott; Büchel, Christian

2016-03-09

Rewarding experiences exert a strong influence on later decision making. While decades of neuroscience research have shown how reinforcement gradually shapes preferences, decisions are often influenced by single past experiences. Surprisingly, relatively little is known about the influence of single learning episodes. Although recent work has proposed a role for episodes in decision making, it is largely unknown whether and how episodic experiences contribute to value-based decision making and how the values of single episodes are represented in the brain. In multiple behavioral experiments and an fMRI experiment, we tested whether and how rewarding episodes could support later decision making. Participants experienced episodes of high reward or low reward in conjunction with incidental, trial-unique neutral pictures. In a surprise test phase, we found that participants could indeed remember the associated level of reward, as evidenced by accurate source memory for value and preferences to re-engage with rewarded objects. Further, in a separate experiment, we found that high-reward objects shown as primes before a gambling task increased financial risk taking. Neurally, re-exposure to objects in the test phase led to significant reactivation of reward-related patterns. Importantly, individual variability in the strength of reactivation predicted value memory performance. Our results provide a novel demonstration that affect-related neural patterns are reactivated during later experience. Reactivation of value information represents a mechanism by which memory can guide decision making. Copyright © 2016 the authors 0270-6474/16/362868-13$15.00/0.

Episodic and working memory function in Primary Progressive Aphasia: A meta-analysis.

PubMed

Eikelboom, Willem S; Janssen, Nikki; Jiskoot, Lize C; van den Berg, Esther; Roelofs, Ardi; Kessels, Roy P C

2018-06-18

The distinction between Primary Progressive Aphasia (PPA) variants remains challenging for clinicians, especially for the non-fluent (nfv-PPA) and the logopenic variants (lv-PPA). Previous research suggests that memory tests might aid this differentiation. This meta-analysis compares memory function among PPA variants. Effects sizes were extracted from 41 studies (N = 849). Random-effects models were used to compare performance on episodic and working memory tests among PPA patients and healthy controls, and between the PPA variants. Memory deficits were frequently observed in PPA compared to controls, with large effect sizes for lv-PPA (Hedges' g = -2.04 [-2.58 to -1.49]), nfv-PPA (Hedges' g = -1.34 [-1.69 to -1.00]), and the semantic variant (sv-PPA; Hedges' g = -1.23 [-1.50 to -0.97]). Sv-PPA showed primarily verbal memory deficits, whereas lv-PPA showed worse performance than nfv-PPA on both verbal and non-verbal memory tests. Memory deficits were more pronounced in lv-PPA compared to nfv-PPA. This suggests that memory tests may be helpful to distinguish between these PPA variants. Copyright © 2018. Published by Elsevier Ltd.

Memory for Sequences of Events Impaired in Typical Aging

ERIC Educational Resources Information Center

Allen, Timothy A.; Morris, Andrea M.; Stark, Shauna M.; Fortin, Norbert J.; Stark, Craig E. L.

2015-01-01

Typical aging is associated with diminished episodic memory performance. To improve our understanding of the fundamental mechanisms underlying this age-related memory deficit, we previously developed an integrated, cross-species approach to link converging evidence from human and animal research. This novel approach focuses on the ability to…

Focal retrograde amnesia and the episodic-semantic distinction.

PubMed

Wheeler, M A; McMillan, C T

2001-03-01

This article reports a review of focal retrograde amnesia (FRA), or the phenomenon of organically based severe memory loss restricted to retrograde, or pretraumatic, memory. Cases of FRA are classified according to the type of memory loss: episodic, semantic, or both. A few different clusters of the disorder were identified. Lesions to either the anterior temporal lobes or the posterior/visual cortex can result in an FRA that devastates retrograde episodic memory, while having smaller effects on semantic memory. A number of left-hemisphere patients have FRA confined to semantic memory. There are several additional examples of FRA following minor cerebral trauma that disrupts either episodic memory alone or both episodic and semantic memory that are not accompanied by evidence of structural brain lesions. We discuss these different profiles of FRA and their implications for the understanding of memory retrieval.

[A new assessment for episodic memory. Episodic memory test and caregiver's episodic memory test].

PubMed

Ojea Ortega, T; González Álvarez de Sotomayor, M M; Pérez González, O; Fernández Fernández, O

2013-10-01

The purpose of the episodic memory test and the caregiver's episodic memory test is to evaluate episodic memory according to its definition in a way that is feasible for families and achieves high degrees of sensitivity and specificity. We administered a test consisting of 10 questions about episodic events to 332 subjects, of whom 65 had Alzheimer's disease (AD), 115 had amnestic MCI (aMCI) and 152 showed no cognitive impairment according to Reisberg's global deterioration scale (GDS). We calculated the test's sensitivity and specificity to distinguish AD from episodic aMCI and from normal ageing. The area under the ROC curve for the diagnosis of aMCI was 0.94 and the best cut-off value was 20; for that value, sensitivity was 89% and specificity was 82%. For a diagnosis of AD, the area under the ROC curve was 0.99 and the best cut-off point was 17, with a sensitivity of 98% and a specificity of 91%. A subsequent study using similar methodology yielded similar results when the test was administered directly by the caregiver. The episodic memory test and the caregiver's episodic memory test are useful as brief screening tools for identifying patients with early-stage AD. It is suitable for use by primary care medical staff and in the home, since it can be administered by a caregiver. The test's limitations are that it must be administered by a reliable caregiver and the fact that it measures episodic memory only. Copyright © 2012 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Episodic Memory Development: Theory of Mind Is Part of Re-Experiencing Experienced Events

ERIC Educational Resources Information Center

Perner, Josef; Kloo, Daniela; Gornik, Edith

2007-01-01

Two experiments with 3 1/2- to 6 1/2-year-old children showed that theory-of-mind development is associated with the growth of episodic memory. Episodic memory was assessed by manipulating informational conditions such that they permit or prevent the formation of episodic memories in terms of re-experiencing the recalled event. Only experienced…

Integrity of white matter structure is related to episodic memory performance in the low-educated elderly.

PubMed

Resende, Elisa de Paula França; Tovar-Moll, Fernanda Freire; Ferreira, Fernanda Meireles; Bramati, Ivanei; de Souza, Leonardo Cruz; Carmona, Karoline Carvalho; Guimarães, Henrique Cerqueira; Carvalho, Viviane Amaral; Barbosa, Maira Tonidandel; Caramelli, Paulo

2017-11-01

The low-educated elderly are a vulnerable population in whom studying the role of white matter integrity on memory may provide insights for understanding how memory declines with aging and disease. Thirty-one participants (22 women), 23 cognitively healthy and eight with cognitive impairment-no dementia, aged 80.4 ± 3.8 years, with 2.2 ± 1.9 years of education, underwent an MRI scan with diffusion tensor imaging (DTI) acquisition. We verified if there were correlations between the performance on the Brief Cognitive Screening Battery (BCSB) and the Rey Auditory Verbal Learning Test (RAVLT) with DTI parameters. The BCSB delayed recall task correlated with frontotemporoparietal connection bundles, with the hippocampal part of the cingulum bilaterally and with the right superior longitudinal fasciculus. The RAVLT learning and delayed recall scores also correlated with the hippocampal part of the cingulum bilaterally. Although preliminary, our study suggests that the integrity of white matter frontotemporoparietal fasciculi seems to play a role in episodic memory performance in the low-educated elderly. This finding opens opportunities to study potential targets for memory decline prevention in vulnerable populations.

Volume of hippocampal subfields and episodic memory in childhood and adolescence.

PubMed

Lee, Joshua K; Ekstrom, Arne D; Ghetti, Simona

2014-07-01

Episodic memory critically depends on the hippocampus to bind the features of an experience into memory. Episodic memory develops in childhood and adolescence, and hippocampal changes during this period may contribute to this development. Little is known, however, about how the hippocampus contributes to episodic memory development. The hippocampus is comprised of several cytoarchitectural subfields with functional significance for episodic memory. However, hippocampal subfields have not been assessed in vivo during child development, nor has their relation with episodic memory been assessed during this period. In the present study, high-resolution T2-weighted images of the hippocampus were acquired in 39 children and adolescents aged 8 to 14 years (M=11.30, SD=2.38), and hippocampal subfields were segmented using a protocol previously validated in adult populations. We first validated the method in children and adolescents and examined age-related differences in hippocampal subfields and correlations between subfield volumes and episodic memory. Significant age-related increases in the subfield volume were observed into early adolescence in the right CA3/DG and CA1. The right CA3/DG subfield volumes were positively correlated with accurate episodic memory for item-color relations, and the right CA3/DG and subiculum were negatively correlated with item false alarm rates. Subfield development appears to follow a protracted developmental trajectory, and likely plays a pivotal role in episodic memory development. Copyright © 2014 Elsevier Inc. All rights reserved.

Sex differences in cognitive functioning in at-risk mental state for psychosis, first episode psychosis and healthy control subjects.

PubMed

Ittig, S; Studerus, E; Papmeyer, M; Uttinger, M; Koranyi, S; Ramyead, A; Riecher-Rössler, A

2015-02-01

Several sex differences in schizophrenia have been reported including differences in cognitive functioning. Studies with schizophrenia patients and healthy controls (HC) indicate that the sex advantage for women in verbal domains is also present in schizophrenia patients. However, findings have been inconsistent. No study focused on sex-related cognitive performance differences in at-risk mental state for psychosis (ARMS) individuals yet. Thus, the aim of the present study was to investigate sex differences in cognitive functioning in ARMS, first episode psychosis (FEP) and HC subjects. We expected a better verbal learning and memory performance of women in all groups. The neuropsychological data analysed in this study were collected within the prospective Früherkennung von Psychosen (FePsy) study. In total, 118 ARMS, 88 FEP individuals and 86 HC completed a cognitive test battery covering the domains of executive functions, attention, working memory, verbal learning and memory, IQ and speed of processing. Women performed better in verbal learning and memory regardless of diagnostic group. By contrast, men as compared to women showed a shorter reaction time during the working memory task across all groups. The results provide evidence that women generally perform better in verbal learning and memory, independent of diagnostic group (ARMS, FEP, HC). The finding of a shorter reaction time for men in the working memory task could indicate that men have a superior working memory performance since they responded faster during the target trials, while maintaining a comparable overall working memory performance level. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Ageing and autobiographical memory for emotional and neutral events

PubMed Central

St. Jacques, Peggy L.; Levine, Brian

2007-01-01

We investigated age-related effects in recall of emotional and neutral autobiographical memories. Protocols were scored according to episodic and non-episodic detail categories using the Autobiographical Interview. Young adults recalled a greater number of episodic details compared to older adults, whereas older adults recalled more semantic details, replicating previous findings. Both young and older adults’ emotional memories contained more overall detail than neutral ones, with the enhancement from emotion-specific to episodic details, but this did not alter the effect of age group on the pattern of episodic and semantic details. However, the age effect on episodic details was attenuated for neutral autobiographical memories. The findings suggest that age differences for emotional autobiographical recollection might reflect a more general pattern of age-related changes in memory, with impaired recall of episodic components and relative sparing of semantic aspects of autobiographical memory in older adults when compared to young adults. PMID:17534107

Children's episodic memory.

PubMed

Ghetti, Simona; Lee, Joshua

2011-07-01

Episodic memory develops during childhood and adolescence. This trajectory depends on several underlying processes. In this article, we first discuss the development of the basic binding processes (e.g., the processes by which elements are bound together to form a memory episode) and control processes (e.g., reasoning and metamemory processes) involved in episodic remembering. Then, we discuss the role of these processes in false-memory formation. In the subsequent sections, we examine the neural substrates of the development of episodic memory. Finally, we discuss atypical development of episodic memory. As we proceed through the article, we suggest potential avenues for future research. WIREs Cogni Sci 2011 2 365-373 DOI: 10.1002/wcs.114 For further resources related to this article, please visit the WIREs website. Copyright © 2010 John Wiley & Sons, Ltd.

The cognitive bases of the development of past and future episodic cognition in preschoolers.

PubMed

Ünal, Gülten; Hohenberger, Annette

2017-10-01

The aim of this study was to use a minimalist framework to examine the joint development of past and future episodic cognition and their underlying cognitive abilities in 3- to 5-year-old Turkish preschoolers. Participants engaged in two main tasks, a what-where-when (www) task to measure episodic memory and a future prediction task to measure episodic future thinking. Three additional tasks were used for predicting children's performance in the two main tasks: a temporal language task, an executive function task, and a spatial working memory task. Results indicated that past and future episodic tasks were significantly correlated with each other even after controlling for age. Hierarchical multiple regressions showed that, after controlling for age, the www task was predicted by executive functions, possibly supporting binding of episodic information and by linguistic abilities. The future prediction task was predicted by linguistic abilities alone, underlining the importance of language for episodic past and future thinking. Copyright © 2017 Elsevier Inc. All rights reserved.

Older adults get episodic memory boosting from noninvasive stimulation of prefrontal cortex during learning

PubMed Central

Brambilla, Michela; Cobelli, Chiara; Cohen, Leonardo G.; Cotelli, Maria

2016-01-01

Episodic memory displays the largest degree of age-related decline, a process that is accelerated in pathological conditions such as amnestic mild cognitive impairment and Alzheimer's disease. Previous studies have shown that the left lateral prefrontal cortex (PFC) contributes to the encoding of episodic memories along the life span. The aim of this randomized, double-blind, placebo-controlled study was to test the hypothesis that anodal trascranial direct current stimulation (tDCS) over the left lateral PFC during the learning phase would enhance delayed recall of verbal episodic memories in elderly individuals. Older adults learned a list of words while receiving anodal or placebo (sham) tDCS. Memory recall was tested 48 hours and 1 month later. The results showed that anodal tDCS strengthened episodic memories, an effect indicated by enhanced delayed recall (48 hours) compared to placebo stimulation (Cohen's d effect size = 1.01). The observation that PFC-tDCS during learning can boost verbal episodic memory in the elderly opens up the possibility to design-specific neurorehabilitation protocols targeted to conditions that affect episodic memory such as mild cognitive impairment. PMID:26923418

A comparison of the effects of a secondary task and lorazepam on cognitive performance.

PubMed

File, S E

1992-01-01

In order to test whether the lorazepam-induced impairments in a variety of cognitive tasks were similar to those of divided attention, the effects of lorazepam (2.5 mg) in healthy volunteers were compared with those requiring subjects to perform an additional task (detecting silences superimposed onto classical music). Neither treatment impaired implicit memory or judgements of frequency. Both treatments impaired performance in tests of speed, lorazepam having the greatest effect on number cancellation and the additional task having the greatest effect on simple reaction time. Both treatments impaired performance in a coding task, in a test of explicit episodic memory and in judgements of recency (indicating impaired coding of contextual information). Lorazepam significantly reduced performance in a word completion task, but this was unimpaired in the group performing the additional task. In general, the pattern of results suggests that there are similarities between the effects of divided attention and lorazepam treatment, and that lorazepam-induced cognitive impairments are not restricted to explicit tests of episodic memory.

Recollection of episodic memory within the medial temporal lobe: behavioural dissociations from other types of memory.

PubMed

Easton, Alexander; Eacott, Madeline J

2010-12-31

In recent years there has been significant debate about whether there is a single medial temporal lobe memory system or dissociable systems for episodic and other types of declarative memory. In addition there has been a similar debate over the dissociability of recollection and familiarity based processes in recognition memory. Here we present evidence from recent work using episodic memory tasks in animals that allows us to explore these issues in more depth. We review studies that demonstrate triple dissociations within the medial temporal lobe, with only the hippocampal system being necessary for episodic memory. Similarly we review behavioural evidence for a dissociation in a task of episodic memory in rats where animals with lesions of the fornix are only impaired at recollection of the episodic memory, not recognition within the same trial. This work, then, supports recent models of dissociable neural systems within the medial temporal lobe but also raises questions for future investigation about the interactions of these medial temporal lobe memory systems with other structures. Copyright © 2009 Elsevier B.V. All rights reserved.

Verbal and non-verbal memory and hippocampal volumes in a memory clinic population.

PubMed

Bonner-Jackson, Aaron; Mahmoud, Shamseldeen; Miller, Justin; Banks, Sarah J

2015-10-15

Better characterization of the relationship between episodic memory and hippocampal volumes is crucial in early detection of neurodegenerative disease. We examined these relationships in a memory clinic population. Participants (n = 226) underwent structural magnetic resonance imaging and tests of verbal (Hopkins Verbal Learning Test-Revised, HVLT-R) and non-verbal (Brief Visuospatial Memory Test-Revised, BVMT-R) memory. Correlational analyses were performed, and analyses on clinical subgroups (i.e., amnestic Mild Cognitive Impairment, non-amnestic Mild Cognitive Impairment, probable Alzheimer's disease, intact memory) were conducted. Positive associations were identified between bilateral hippocampal volumes and both memory measures, and BVMT-R learning slope was more strongly positively associated with hippocampal volumes than HVLT-R learning slope. Amnestic Mild Cognitive Impairment (aMCI) participants showed specific positive associations between BVMT-R performance and hippocampal volumes bilaterally. Additionally, analyses of the aMCI group showed trend-level evidence of material-specific lateralization, such that retention of verbal information was positively associated with left hippocampal volume, whereas learning curve and retention of non-verbal information was positively associated with right hippocampal volume. Findings support the link between episodic memory and hippocampal volumes in a memory clinic population. Non-verbal memory measures also may have higher diagnostic value, particularly in individuals at elevated risk for Alzheimer's disease.

Effects of semantic relatedness on recall of stimuli preceding emotional oddballs.

PubMed

Smith, Ryan M; Beversdorf, David Q

2008-07-01

Semantic and episodic memory networks function as highly interconnected systems, both relying on the hippocampal/medial temporal lobe complex (HC/MTL). Episodic memory encoding triggers the retrieval of semantic information, serving to incorporate contextual relationships between the newly acquired memory and existing semantic representations. While emotional material augments episodic memory encoding at the time of stimulus presentation, interactions between emotion and semantic memory that contribute to subsequent episodic recall are not well understood. Using a modified oddball task, we examined the modulatory effects of negative emotion on semantic interactions with episodic memory by measuring the free-recall of serially presented neutral or negative words varying in semantic relatedness. We found increased free-recall for words related to and preceding emotionally negative oddballs, suggesting that negative emotion can indirectly facilitate episodic free-recall by enhancing semantic contributions during encoding. Our findings demonstrate the ability of emotion and semantic memory to interact to mutually enhance free-recall.

Dissociation between memory accuracy and memory confidence following bilateral parietal lesions.

PubMed

Simons, Jon S; Peers, Polly V; Mazuz, Yonatan S; Berryhill, Marian E; Olson, Ingrid R

2010-02-01

Numerous functional neuroimaging studies have observed lateral parietal lobe activation during memory tasks: a surprise to clinicians who have traditionally associated the parietal lobe with spatial attention rather than memory. Recent neuropsychological studies examining episodic recollection after parietal lobe lesions have reported differing results. Performance was preserved in unilateral lesion patients on source memory tasks involving recollecting the context in which stimuli were encountered, and impaired in patients with bilateral parietal lesions on tasks assessing free recall of autobiographical memories. Here, we investigated a number of possible accounts for these differing results. In 3 experiments, patients with bilateral parietal lesions performed as well as controls at source recollection, confirming the previous unilateral lesion results and arguing against an explanation for those results in terms of contralesional compensation. Reducing the behavioral relevance of mnemonic information critical to the source recollection task did not affect performance of the bilateral lesion patients, indicating that the previously observed reduced autobiographical free recall might not be due to impaired bottom-up attention. The bilateral patients did, however, exhibit reduced confidence in their source recollection abilities across the 3 experiments, consistent with a suggestion that parietal lobe lesions might lead to impaired subjective experience of rich episodic recollection.

Fornix as an imaging marker for episodic memory deficits in healthy aging and in various neurological disorders

PubMed Central

Douet, Vanessa; Chang, Linda

2015-01-01

The fornix is a part of the limbic system and constitutes the major efferent and afferent white matter tracts from the hippocampi. The underdevelopment of or injuries to the fornix are strongly associated with memory deficits. Its role in memory impairments was suggested long ago with cases of surgical forniceal transections. However, recent advances in brain imaging techniques, such as diffusion tensor imaging, have revealed that macrostructural and microstructural abnormalities of the fornix correlated highly with declarative and episodic memory performance. This structure appears to provide a robust and early imaging predictor for memory deficits not only in neurodegenerative and neuroinflammatory diseases, such as Alzheimer's disease and multiple sclerosis, but also in schizophrenia and psychiatric disorders, and during neurodevelopment and “typical” aging. The objective of the manuscript is to present a systematic review regarding published brain imaging research on the fornix, including the development of its tracts, its role in various neurological diseases, and its relationship to neurocognitive performance in human studies. PMID:25642186

Don’t be Too Strict with Yourself! Rigid Negative Self-Representation in Healthy Subjects Mimics the Neurocognitive Profile of Depression for Autobiographical Memory

PubMed Central

Sperduti, Marco; Martinelli, Pénélope; Kalenzaga, Sandrine; Devauchelle, Anne-Dominique; Lion, Stéphanie; Malherbe, Caroline; Gallarda, Thierry; Amado, Isabelle; Krebs, Marie-Odile; Oppenheim, Catherine; Piolino, Pascale

2013-01-01

Autobiographical memory (AM) comprises representation of both specific (episodic) and generic (semantic) personal information. Depression is characterized by a shift from episodic to semantic AM retrieval. According to theoretical models, this process (“overgeneralization”), would be linked to reduced executive resources. Moreover, “overgeneral” memories, accompanied by a negativity bias in depression, lead to a pervasive negative self-representation. As executive functions and AM specificity are also closely intricate among “non-clinical” populations, “overgeneral” memories could result in depressive emotional responses. Consequently, our hypothesis was that the neurocognitive profile of healthy subjects showing a rigid negative self-image would mimic that of patients. Executive functions and self-image were measured and brain activity was recorded, by means of fMRI, during episodic AMs retrieval in young healthy subjects. The results show an inverse correlation, that is, a more rigid and negative self-image produces lower performances in both executive and specific memories. Moreover, higher negative self-image is associated with decreased activity in the left ventro-lateral prefrontal and in the anterior cingulate cortex, repeatedly shown to exhibit altered functioning in depression. Activity in these regions, on the contrary, positively correlates with executive and memory performances, in line with their role in executive functions and AM retrieval. These findings suggest that rigid negative self-image could represent a marker or a vulnerability trait of depression by being linked to reduced executive function efficiency and episodic AM decline. These results are encouraging for psychotherapeutic approaches aimed at cognitive flexibility in depression and other psychiatric disorders. PMID:23734107

Transient global amnesia: implicit/explicit memory dissociation and PET assessment of brain perfusion and oxygen metabolism in the acute stage.

PubMed

Eustache, F; Desgranges, B; Petit-Taboué, M C; de la Sayette, V; Piot, V; Sablé, C; Marchal, G; Baron, J C

1997-09-01

To assess explicit memory and two components of implicit memory--that is, perceptual-verbal skill learning and lexical-semantic priming effects--as well as resting cerebral blood flow (CBF) and oxygen metabolism (CMRO2) during the acute phase of transient global amnesia. In a 59 year old woman, whose amnestic episode fulfilled all current criteria for transient global amnesia, a neuropsychological protocol was administered, including word learning, story recall, categorical fluency, mirror reading, and word stem completion tasks. PET was performed using the (15)O steady state inhalation method, while the patient still exhibited severe anterograde amnesia and was interleaved with the cognitive tests. There was a clear cut dissociation between impaired long term episodic memory and preserved implicit memory for its two components. Categorical fluency was significantly altered, suggesting word retrieval strategy--rather than semantic memory--impairment. The PET study disclosed a reduced CMRO2 with relatively or fully preserved CBF in the left prefrontotemporal cortex and lentiform nucleus, and the reverse pattern over the left occipital cortex. The PET alterations with patchy CBF-CMRO2 uncoupling would be compatible with a migraine-like phenomenon and indicate that the isolated assessment of perfusion in transient global amnesia may be misleading. The pattern of metabolic depression, with sparing of the hippocampal area, is one among the distinct patterns of brain dysfunction that underlie the (apparently) uniform clinical presentation of transient global amnesia. The finding of a left prefrontal hypometabolism in the face of impaired episodic memory and altered verbal fluency would fit present day concepts from PET activation studies about the role of this area in episodic and semantic memory encoding/retrieval. Likewise, the changes affecting the lenticular nucleus but sparing the caudate would be consistent with the normal performance in perceptual-verbal skill learning. Finally, unaltered lexical-semantic priming effects, despite left temporal cortex hypometabolism, suggest that these processes are subserved by a more distributed neocortical network.

Executive functions deficit in mild cognitive impairment.

PubMed

Traykov, Latchezar; Raoux, Nadine; Latour, Florence; Gallo, Livia; Hanon, Olivier; Baudic, Sophie; Bayle, Catherine; Wenisch, Emilie; Remy, Philippe; Rigaud, Anne-Sophie

2007-12-01

To investigate whether patients diagnosed with amnestic mild cognitive impairment (MCI) have also impairment in attention/executive functions, and therefore to clarify whether all subcomponents of executive control are equally affected in MCI. MCI refers to the transitional state between normal aging and dementia. Amnestic MCI is characterized by impaired episodic memory, although subtle impairment of executive functions has been noted on neuropsychologic tests. We investigated 20 MCI patients and 20 normal controls using episodic memory, attention/executive functions, language, and praxis tests. MCI patients had significantly lower scores on all measures of the Free and Cued Selective Reminding Test (P<0.05 to 0.01) than controls. Furthermore, MCI had a greater number of perseverations (P<0.01) on Modified Card Sorting Test and the lowest performance on the Stroop Test (P<0.02). Our findings showed impairment in episodic memory performance in MCI as compared with that of controls. In addition, MCI patients had problems with response inhibition, switching, and cognitive flexibility, which encompass various aspects of executive functions. This suggests that MCI may be identified by using a more detailed procedure for the assessment of cognitive decline than the evaluation of memory alone.

The Episodic Nature of Episodic-Like Memories

ERIC Educational Resources Information Center

Easton, Alexander; Webster, Lisa A. D.; Eacott, Madeline J.

2012-01-01

Studying episodic memory in nonhuman animals has proved difficult because definitions in humans require conscious recollection. Here, we assessed humans' experience of episodic-like recognition memory tasks that have been used with animals. It was found that tasks using contextual information to discriminate events could only be accurately…

Episodic Memories

ERIC Educational Resources Information Center

Conway, Martin A.

2009-01-01

An account of episodic memories is developed that focuses on the types of knowledge they represent, their properties, and the functions they might serve. It is proposed that episodic memories consist of "episodic elements," summary records of experience often in the form of visual images, associated to a "conceptual frame" that provides a…

Differential Medial Temporal Lobe and Parietal Cortical Contributions to Real-world Autobiographical Episodic and Autobiographical Semantic Memory.

PubMed

Brown, Thackery I; Rissman, Jesse; Chow, Tiffany E; Uncapher, Melina R; Wagner, Anthony D

2018-04-18

Autobiographical remembering can depend on two forms of memory: episodic (event) memory and autobiographical semantic memory (remembering personally relevant semantic knowledge, independent of recalling a specific experience). There is debate about the degree to which the neural signals that support episodic recollection relate to or build upon autobiographical semantic remembering. Pooling data from two fMRI studies of memory for real-world personal events, we investigated whether medial temporal lobe (MTL) and parietal subregions contribute to autobiographical episodic and semantic remembering. During scanning, participants made memory judgments about photograph sequences depicting past events from their life or from others' lives, and indicated whether memory was based on episodic or semantic knowledge. Results revealed several distinct functional patterns: activity in most MTL subregions was selectively associated with autobiographical episodic memory; the hippocampal tail, superior parietal lobule, and intraparietal sulcus were similarly engaged when memory was based on retrieval of an autobiographical episode or autobiographical semantic knowledge; and angular gyrus demonstrated a graded pattern, with activity declining from autobiographical recollection to autobiographical semantic remembering to correct rejections of novel events. Collectively, our data offer insights into MTL and parietal cortex functional organization, and elucidate circuitry that supports different forms of real-world autobiographical memory.

Retrograde episodic memory and emotion: a perspective from patients with dissociative amnesia.

PubMed

Reinhold, Nadine; Markowitsch, Hans J

2009-09-01

With his recent definition of episodic memory Tulving [Tulving, E. (2005). Episodic memory and autonoesis: Uniquely human? In H. Terrace & J. Metcalfe (Eds.), The missing link in cognition: Evolution of self-knowing consciousness (pp. 3-56). New York: Oxford University Press] claims that this memory system is uniquely human and thereby distinguishes human beings from other, even highly developed, mammals. First we will define the term episodic memory as it is currently used in neuropsychological research by specifying the three underlying concepts of subjective time, autonoëtic consciousness, and the self. By doing so, we will strongly focus on retrograde episodic memory and its relation to emotion and self-referential processing. We support this relation with a discussion of autobiographical memory functions in psychiatric disorders such as dissociative amnesia. To illustrate the connection of emotion and retrograde episodic memory we shortly present neuropsychological data of two cases of dissociative amnesia. Both cases serve to point to the protective mechanism of a block of self-endangering memories from the episodic memory system, often described as the mnestic block syndrome. On the basis of these cases and supportive results from further cases we will conclude by pointing out similarities and differences of patients with organic and dissociative (psychogenic) amnesia.

Individual differences in associative memory among older adults explained by hippocampal subfield structure and function.

PubMed

Carr, Valerie A; Bernstein, Jeffrey D; Favila, Serra E; Rutt, Brian K; Kerchner, Geoffrey A; Wagner, Anthony D

2017-11-07

Older adults experience impairments in episodic memory, ranging from mild to clinically significant. Given the critical role of the medial temporal lobe (MTL) in episodic memory, age-related changes in MTL structure and function may partially account for individual differences in memory. Using ultra-high-field 7T structural MRI and high-resolution 3T functional MRI (hr-fMRI), we evaluated MTL subfield thickness and function in older adults representing a spectrum of cognitive health. Participants performed an associative memory task during hr-fMRI in which they encoded and later retrieved face-name pairs. Motivated by prior research, we hypothesized that differences in performance would be explained by the following: ( i ) entorhinal cortex (ERC) and CA1 apical neuropil layer [CA1-stratum radiatum lacunosum moleculare (SRLM)] thickness, and ( ii ) activity in ERC and the dentate gyrus (DG)/CA3 region. Regression analyses revealed that this combination of factors significantly accounted for variability in memory performance. Among these metrics, CA1-SRLM thickness was positively associated with memory, whereas DG/CA3 retrieval activity was negatively associated with memory. Furthermore, including structural and functional metrics in the same model better accounted for performance than did single-modality models. These results advance the understanding of how independent but converging influences of both MTL subfield structure and function contribute to age-related memory impairment, complementing findings in the rodent and human postmortem literatures.

The interplay of episodic and semantic memory in guiding repeated search in scenes.

PubMed

Võ, Melissa L-H; Wolfe, Jeremy M

2013-02-01

It seems intuitive to think that previous exposure or interaction with an environment should make it easier to search through it and, no doubt, this is true in many real-world situations. However, in a recent study, we demonstrated that previous exposure to a scene does not necessarily speed search within that scene. For instance, when observers performed as many as 15 searches for different objects in the same, unchanging scene, the speed of search did not decrease much over the course of these multiple searches (Võ & Wolfe, 2012). Only when observers were asked to search for the same object again did search become considerably faster. We argued that our naturalistic scenes provided such strong "semantic" guidance-e.g., knowing that a faucet is usually located near a sink-that guidance by incidental episodic memory-having seen that faucet previously-was rendered less useful. Here, we directly manipulated the availability of semantic information provided by a scene. By monitoring observers' eye movements, we found a tight coupling of semantic and episodic memory guidance: Decreasing the availability of semantic information increases the use of episodic memory to guide search. These findings have broad implications regarding the use of memory during search in general and particularly during search in naturalistic scenes. Copyright © 2012 Elsevier B.V. All rights reserved.

Temporal association tracts and the breakdown of episodic memory in mild cognitive impairment

PubMed Central

Metzler-Baddeley, Claudia; Hunt, Sarah; Jones, Derek K.; Leemans, Alexander; Aggleton, John P.

2012-01-01

Objective: To examine the pattern of association between microstructure of temporal lobe connections and the breakdown of episodic memory that is a core feature of mild cognitive impairment (MCI). Methods: Twenty-five individuals with MCI and 20 matched controls underwent diffusion MRI and cognitive assessment. Three temporal pathways were reconstructed by tractography: fornix, parahippocampal cingulum (PHC), and uncinate fasciculus. Tissue volume fraction—a tract-specific measure of atrophy—and microstructural measures were derived for each tract. To test specificity of associations, a comparison tract (corticospinal tract) and control cognitive domains were also examined. Results: In MCI, tissue volume fraction was reduced in the fornix. Axial and radial diffusivity were increased in uncinate and PHC implying more subtle microstructural change. In controls, tissue volume fraction in the fornix was the predominant correlate of free recall. In contrast, in MCI, the strongest relationship was with left PHC. Microstructure of uncinate and PHC also correlated with recognition memory, and recognition confidence, in MCI. Conclusions: Episodic memory in MCI is related to the structure of multiple temporal association pathways. These associations are not confined to the fornix, as they are in healthy young and older adults. In MCI, because of a compromised fornix, alternative pathways may contribute disproportionally to episodic memory performance. PMID:23175726

Memory evaluation in mild cognitive impairment using recall and recognition tests.

PubMed

Bennett, Ilana J; Golob, Edward J; Parker, Elizabeth S; Starr, Arnold

2006-11-01

Amnestic mild cognitive impairment (MCI) is a selective episodic memory deficit that often indicates early Alzheimer's disease. Episodic memory function in MCI is typically defined by deficits in free recall, but can also be tested using recognition procedures. To assess both recall and recognition in MCI, MCI (n = 21) and older comparison (n = 30) groups completed the USC-Repeatable Episodic Memory Test. Subjects memorized two verbally presented 15-item lists. One list was used for three free recall trials, immediately followed by yes/no recognition. The second list was used for three-alternative forced-choice recognition. Relative to the comparison group, MCI had significantly fewer hits and more false alarms in yes/no recognition, and were less accurate in forced-choice recognition. Signal detection analysis showed that group differences were not due to response bias. Discriminant function analysis showed that yes/no recognition was a better predictor of group membership than free recall or forced-choice measures. MCI subjects recalled fewer items than comparison subjects, with no group differences in repetitions, intrusions, serial position effects, or measures of recall strategy (subjective organization, recall consistency). Performance deficits on free recall and recognition in MCI suggest a combination of both tests may be useful for defining episodic memory impairment associated with MCI and early Alzheimer's disease.

The interplay of episodic and semantic memory in guiding repeated search in scenes

PubMed Central

Võ, Melissa L.-H.; Wolfe, Jeremy M.

2012-01-01

It seems intuitive to think that previous exposure or interaction with an environment should make it easier to search through it and, no doubt, this is true in many real-world situations. However, in a recent study, we demonstrated that previous exposure to a scene does not necessarily speed search within that scene. For instance, when observers performed as many as fifteen searches for different objects in the same, unchanging scene, the speed of search did not decrease much over the course of these multiple searches (Võ & Wolfe, 2012). Only when observers were asked to search for the same object again did search become considerably faster. We argued that our naturalistic scenes provided such strong “semantic” guidance — e.g., knowing that a faucet is usually located near a sink — that guidance by incidental episodic memory — having seen that faucet previously — was rendered less useful. Here, we directly manipulated the availability of semantic information provided by a scene. By monitoring observers’ eye movements, we found a tight coupling of semantic and episodic memory guidance: Decreasing the availability of semantic information increases the use of episodic memory to guide search. These findings have broad implications regarding the use of memory during search in general and particularly during search in naturalistic scenes. PMID:23177141

Tau and β-Amyloid Are Associated with Medial Temporal Lobe Structure, Function, and Memory Encoding in Normal Aging

PubMed Central

2017-01-01

Normal aging is associated with a decline in episodic memory and also with aggregation of the β-amyloid (Aβ) and tau proteins and atrophy of medial temporal lobe (MTL) structures crucial to memory formation. Although some evidence suggests that Aβ is associated with aberrant neural activity, the relationships among these two aggregated proteins, neural function, and brain structure are poorly understood. Using in vivo human Aβ and tau imaging, we demonstrate that increased Aβ and tau are both associated with aberrant fMRI activity in the MTL during memory encoding in cognitively normal older adults. This pathological neural activity was in turn associated with worse memory performance and atrophy within the MTL. A mediation analysis revealed that the relationship with regional atrophy was explained by MTL tau. These findings broaden the concept of cognitive aging to include evidence of Alzheimer's disease-related protein aggregation as an underlying mechanism of age-related memory impairment. SIGNIFICANCE STATEMENT Alterations in episodic memory and the accumulation of Alzheimer's pathology are common in cognitively normal older adults. However, evidence of pathological effects on episodic memory has largely been limited to β-amyloid (Aβ). Because Aβ and tau often cooccur in older adults, previous research offers an incomplete understanding of the relationship between pathology and episodic memory. With the recent development of in vivo tau PET radiotracers, we show that Aβ and tau are associated with different aspects of memory encoding, leading to aberrant neural activity that is behaviorally detrimental. In addition, our results provide evidence linking Aβ- and tau-associated neural dysfunction to brain atrophy. PMID:28213439

The Spanish version of Face-Name Associative Memory Exam (S-FNAME) performance is related to amyloid burden in Subjective Cognitive Decline.

PubMed

Sanabria, Angela; Alegret, Montserrat; Rodriguez-Gomez, Octavio; Valero, Sergi; Sotolongo-Grau, Oscar; Monté-Rubio, Gemma; Abdelnour, Carla; Espinosa, Ana; Ortega, Gemma; Perez-Cordon, Alba; Gailhajanet, Anna; Hernandez, Isabel; Rosende-Roca, Maitee; Vargas, Liliana; Mauleon, Ana; Sanchez, Domingo; Martin, Elvira; Rentz, Dorene M; Lomeña, Francisco; Ruiz, Agustin; Tarraga, Lluis; Boada, Merce

2018-02-28

The Face-Name Associative Memory Exam (FNAME) is a paired associative memory test created to detect memory deficits in individuals with preclinical Alzheimer's disease (AD). Worse performance on FNAME in cognitively healthy individuals were found related to higher amyloid beta (Aβ) burden measured with Positron-Emission-Tomography using 11 C-PiB (PiB-PET). We previously reported normative data of a Spanish version of FNAME (S-FNAME) in cognitively healthy Spanish-speaking subjects. The aim of the present study was to determine whether performance on S-FNAME was associated with Aβ burden in subjective cognitive decline (SCD) individuals. 200 SCD subjects received neurological and neuropsychological assessments, including the S-FNAME and the Word List task from the Wechsler-Memory-Scale-III (WMS-III). Moreover, they received an MRI and (18)F-Florbetaben Positron-Emission-Tomography (FBB-PET) to measure Aβ burden. Three cognitive factor composites were derived for the episodic memory measures (face-name [SFN-N], face-occupation [SFN-O] and WMS-III) to determine whether episodic memory performance was related to Aβ deposition. Higher global Aβ deposition was significantly related to worse performance on SFN-N but not with SFN-O or WMS-III Composite. Moreover, worse SFN-N performance was significantly related to higher Aβ deposition in bilateral  Posterior Cingulate Cortex. The S-FNAME may be a promising neuropsychological tool for detecting SCD individuals with preclinical AD.

Sleep Benefits in Parallel Implicit and Explicit Measures of Episodic Memory

ERIC Educational Resources Information Center

Weber, Frederik D.; Wang, Jing-Yi; Born, Jan; Inostroza, Marion

2014-01-01

Research in rats using preferences during exploration as a measure of memory has indicated that sleep is important for the consolidation of episodic-like memory, i.e., memory for an event bound into specific spatio-temporal context. How these findings relate to human episodic memory is unclear. We used spontaneous preferences during visual…

A decade of changes in brain volume and cognition.

PubMed

Aljondi, Rowa; Szoeke, Cassandra; Steward, Chris; Yates, Paul; Desmond, Patricia

2018-05-09

Brain atrophy can occur several decades prior to onset of cognitive impairments. However, few longitudinal studies have examined the relationship between brain volume changes and cognition over a long follow-up period in healthy elderly women. In the present study we investigate the relationship between whole brain and hippocampal atrophy rates and longitudinal changes in cognition, including verbal episodic memory and executive function, in older women. We also examine whether baseline brain volume predicts subsequent changes in cognitive performance over a 10-year period. A total of 60 individuals from the population-based Women's Healthy Ageing Project with a mean age at baseline of 59 years underwent 3T MRI. Of these, 40 women completed follow-up cognitive assessments, 23 of whom had follow-up MRI scans. Linear regression analysis was used to examine the relationship between brain atrophy and changes in verbal episodic memory and executive function over a 10-year period. The results show that baseline measurements of frontal and temporal grey matter volumes predict changes in verbal episodic memory performance, whereas hippocampal volume at baseline is associated with changes in executive function performance over a 10-year period of follow-ups. In addition, higher whole brain and hippocampal atrophy rates are correlated with a decline in verbal episodic memory. These findings indicate that in addition to atrophy rate, smaller regional grey matter volumes even 10 years prior is associated with increased rates of cognitive decline. This study suggests useful neuroimaging biomarkers for the prediction of cognitive decline in healthy elderly women.

The role of decision-making in cannabis-related problems among young adults

PubMed Central

Gonzalez, Raul; Schuster, Randi M.; Mermelstein, Robin M.; Diviak, Kathleen R.

2015-01-01

Background Deficits in decision-making and episodic memory are often reported among heavy cannabis users, yet little is known on how they influence negative consequences from cannabis use. Individual differences in decision-making may explain, in part, why some individuals experience significant problems from their cannabis use whereas others do not. We hypothesized that poor decision-making would moderate relationships between amount of cannabis use and problems from cannabis use whereas episodic memory performance would not. Method Young adult cannabis users (n = 52) with cannabis as their drug of choice and with minimal comorbidities completed semi-structured interviews, self-report questionnaires, and measures of neurocognitive functioning, with decision-making accessed via the Iowa Gambling Task (IGT), episodic memory via the Hopkins Verbal Learning Test – Revised (HVLT) and problems from cannabis use with the Marijuana Problems Scale. Results Strong relationships were observed between amount of cannabis use (lifetime, 12-month, and 30-day) and problems reported from use, but only among participants with Low (impaired) decision-making (R2 = .39 to .51; p < .01). No significant relationships were observed among those with better (low average to high average) decision-making performance (p > .05). In contrast, episodic memory performance was not a significant moderator of the relationship between amount of cannabis use and cannabis problems (p > .05). Conclusions Cannabis users with poor decision-making may be at greater risk for experiencing significant negative consequences from their cannabis use. Our results lend further support to emerging evidence of decision-making as a risk factor for addiction and extend these findings to cannabis users. PMID:26199058

Sketching to Remember: Episodic Free Recall Task Support for Child Witnesses and Victims with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Mattison, Michelle L. A.; Dando, Coral J.; Ormerod, Thomas C.

2015-01-01

Deficits in episodic free-recall memory performance have been reported in children with autism spectrum disorder (ASD), yet best practice dictates that child witness/victim interviews commence with a free-recall account. No "tools" exist to support children with ASD to freely recall episodic information. Here, the efficacy of a novel…

Sex differences in cognition among illiterate Bangladeshis: a comparison with literate Bangladeshis and Swedes.

PubMed

Herlitz, Agneta; Kabir, Zarina N

2006-12-01

We investigated the presence and magnitude of sex differences in late adulthood, assessing 426 illiterate Bangladeshis, 239 literate Bangladeshis, and 598 Swedes. The cognitive domains examined included calculation, episodic memory, spatial visualization, and global cognitive ability. In general, men performed at a higher level than women on tasks assessing calculation and spatial visualization, whereas women performed at a higher level than men on the episodic memory task. Notably, the pattern of cognitive sex differences was similar irrespective of nationality and literacy, although the magnitude of the male advantage was inversely related to level of education. Finally, the low performance of the illiterate women demonstrated the penalizing effect restrictions in public exposure might have on cognitive performance.

Left frontal cortex connectivity underlies cognitive reserve in prodromal Alzheimer disease

PubMed Central

Franzmeier, Nicolai; Duering, Marco; Weiner, Michael; Dichgans, Martin

2017-01-01

Objective: To test whether higher global functional connectivity of the left frontal cortex (LFC) in Alzheimer disease (AD) is associated with more years of education (a proxy of cognitive reserve [CR]) and mitigates the association between AD-related fluorodeoxyglucose (FDG)-PET hypometabolism and episodic memory. Methods: Forty-four amyloid-PET–positive patients with amnestic mild cognitive impairment (MCI-Aβ+) and 24 amyloid-PET–negative healthy controls (HC) were included. Voxel-based linear regression analyses were used to test the association between years of education and FDG-PET in MCI-Aβ+, controlled for episodic memory performance. Global LFC (gLFC) connectivity was computed through seed-based resting-state fMRI correlations between the LFC (seed) and each voxel in the gray matter. In linear regression analyses, education as a predictor of gLFC connectivity and the interaction of gLFC connectivity × FDG-PET hypometabolism on episodic memory were tested. Results: FDG-PET metabolism in the precuneus was reduced in MCI-Aβ+ compared to HC (p = 0.028), with stronger reductions observed in MCI-Aβ+ with more years of education (p = 0.006). In MCI-Aβ+, higher gLFC connectivity was associated with more years of education (p = 0.021). At higher levels of gLFC connectivity, the association between precuneus FDG-PET hypometabolism and lower memory performance was attenuated (p = 0.027). Conclusions: Higher gLFC connectivity is a functional substrate of CR that helps to maintain episodic memory relatively well in the face of emerging FDG-PET hypometabolism in early-stage AD. PMID:28188306

Neural correlates of reward-based spatial learning in persons with cocaine dependence.

PubMed

Tau, Gregory Z; Marsh, Rachel; Wang, Zhishun; Torres-Sanchez, Tania; Graniello, Barbara; Hao, Xuejun; Xu, Dongrong; Packard, Mark G; Duan, Yunsuo; Kangarlu, Alayar; Martinez, Diana; Peterson, Bradley S

2014-02-01

Dysfunctional learning systems are thought to be central to the pathogenesis of and impair recovery from addictions. The functioning of the brain circuits for episodic memory or learning that support goal-directed behavior has not been studied previously in persons with cocaine dependence (CD). Thirteen abstinent CD and 13 healthy participants underwent MRI scanning while performing a task that requires the use of spatial cues to navigate a virtual-reality environment and find monetary rewards, allowing the functional assessment of the brain systems for spatial learning, a form of episodic memory. Whereas both groups performed similarly on the reward-based spatial learning task, we identified disturbances in brain regions involved in learning and reward in CD participants. In particular, CD was associated with impaired functioning of medial temporal lobe (MTL), a brain region that is crucial for spatial learning (and episodic memory) with concomitant recruitment of striatum (which normally participates in stimulus-response, or habit, learning), and prefrontal cortex. CD was also associated with enhanced sensitivity of the ventral striatum to unexpected rewards but not to expected rewards earned during spatial learning. We provide evidence that spatial learning in CD is characterized by disturbances in functioning of an MTL-based system for episodic memory and a striatum-based system for stimulus-response learning and reward. We have found additional abnormalities in distributed cortical regions. Consistent with findings from animal studies, we provide the first evidence in humans describing the disruptive effects of cocaine on the coordinated functioning of multiple neural systems for learning and memory.

Left frontal cortex connectivity underlies cognitive reserve in prodromal Alzheimer disease.

PubMed

Franzmeier, Nicolai; Duering, Marco; Weiner, Michael; Dichgans, Martin; Ewers, Michael

2017-03-14

To test whether higher global functional connectivity of the left frontal cortex (LFC) in Alzheimer disease (AD) is associated with more years of education (a proxy of cognitive reserve [CR]) and mitigates the association between AD-related fluorodeoxyglucose (FDG)-PET hypometabolism and episodic memory. Forty-four amyloid-PET-positive patients with amnestic mild cognitive impairment (MCI-Aβ+) and 24 amyloid-PET-negative healthy controls (HC) were included. Voxel-based linear regression analyses were used to test the association between years of education and FDG-PET in MCI-Aβ+, controlled for episodic memory performance. Global LFC (gLFC) connectivity was computed through seed-based resting-state fMRI correlations between the LFC (seed) and each voxel in the gray matter. In linear regression analyses, education as a predictor of gLFC connectivity and the interaction of gLFC connectivity × FDG-PET hypometabolism on episodic memory were tested. FDG-PET metabolism in the precuneus was reduced in MCI-Aβ+ compared to HC ( p = 0.028), with stronger reductions observed in MCI-Aβ+ with more years of education ( p = 0.006). In MCI-Aβ+, higher gLFC connectivity was associated with more years of education ( p = 0.021). At higher levels of gLFC connectivity, the association between precuneus FDG-PET hypometabolism and lower memory performance was attenuated ( p = 0.027). Higher gLFC connectivity is a functional substrate of CR that helps to maintain episodic memory relatively well in the face of emerging FDG-PET hypometabolism in early-stage AD. © 2017 American Academy of Neurology.

A Steady State Visually Evoked Potential Investigation of Memory and Ageing

ERIC Educational Resources Information Center

Macpherson, Helen; Pipingas, Andrew; Silberstein, Richard

2009-01-01

Old age is generally accompanied by a decline in memory performance. Specifically, neuroimaging and electrophysiological studies have revealed that there are age-related changes in the neural correlates of episodic and working memory. This study investigated age-associated changes in the steady state visually evoked potential (SSVEP) amplitude and…

Is Episodic Future Thinking Important for Instrumental Activities of Daily Living? A Study in Neurological Patients and Healthy Older Adults.

PubMed

Brunette, Amanda M; Calamia, Matthew; Black, Jenah; Tranel, Daniel

2018-06-11

Episodic future thinking is the ability to mentally project oneself into the future. This construct has been explored extensively in cognitive neuroscience and may be relevant for adaptive functioning. However, it has not been determined whether the measurement of episodic future thinking might be valuable in a clinical neuropsychological setting. The current study investigated (1) the relationship between episodic future thinking and instrumental activities of daily living (IADLs); and (2) whether episodic future thinking is related to IADLs over and above standard measures of cognition. Sixty-one older adults with heterogeneous neurological conditions and 41 healthy older adults completed a future thinking task (the adapted Autobiographical Interview), a performance-based measure of instrumental activities of daily living (the Independent Living Scales), and standard clinical measures of memory and executive functioning. Episodic future thinking significantly predicted IADLs after accounting for age, education, gender, and depression (increase in R2 = .050, p = .010). Episodic future thinking significantly predicted IADLs over and above executive functioning (increase in R2 = .025, p = .030), but was not predictive of IADLs over and above memory (p = .157). This study suggests that episodic future thinking is significantly associated with IADLs, beyond what can be accounted for by executive functioning. However, episodic future thinking did not predict IADLs over and above memory. Overall, there is limited evidence for the clinical utility of episodic future thinking. The findings suggest that an episodic future thinking task does not provide enough valuable information about IADLs to justify its inclusion in a clinical neuropsychological setting.

Self-reported and informant-reported memory functioning and awareness in patients with mild cognitive impairment and Alzheimer´s disease.

PubMed

Silva, Martina Rios; Moser, Doris; Pflüger, Melanie; Pusswald, Gisela; Stögmann, Elisabeth; Dal-Bianco, Peter; Auff, Eduard; Lehrner, Johann

2016-06-01

Awareness of subjective memory is an important factor for adequate treatment of patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). This study served to find out whether awareness of subjective memory complies with objective performance, if differences in awareness are observed longitudinally and whether decrease of awareness can serve as a predictor of AD in MCI patients. Thirty-four patients with MCI seeking help in a memory outpatient clinic were included. All participants underwent thorough neuropsychological examination. Awareness of subjective memory was obtained by calculating difference scores between patient and informant ratings on a 16-item questionnaire concerning complaints about loss of memory in every-day life. Retesting was performed after a mean follow-up period of 24 months. Whole group analyses showed that awareness remained relatively stable across time. Self-reported memory complaints correlated with episodic memory at baseline and with performance on a language task at follow-up. Retests displayed decrease of awareness. At group level differences in awareness between both times of assessment were not significant for MCI and MCI patients converting to mild AD at follow-up. The predictive value of awareness was low. Awareness of subjective memory deficit is linked to episodic memory function and decreases with decline of cognitive ability. Further studies evaluating predictive power of awareness of subjective memory should include a larger patient sample.

Episodic Memories and Their Relevance for Psychoactive Drug Use and Addiction

PubMed Central

Müller, Christian P.

2013-01-01

The majority of adult people in western societies regularly consume psychoactive drugs. While this consumption is integrated in everyday life activities and controlled in most consumers, it may escalate and result in drug addiction. Non-addicted drug use requires the systematic establishment of highly organized behaviors, such as drug-seeking and -taking. While a significant role for classical and instrumental learning processes is well established in drug use and abuse, declarative drug memories have largely been neglected in research. Episodic memories are an important part of the declarative memories. Here a role of episodic drug memories in the establishment of non-addicted drug use and its transition to addiction is suggested. In relation to psychoactive drug consumption, episodic drug memories are formed when a person prepares for consumption, when the drug is consumed and, most important, when acute effects, withdrawal, craving, and relapse are experienced. Episodic drug memories are one-trial memories with emotional components that can be much stronger than “normal” episodic memories. Their establishment coincides with drug-induced neuronal activation and plasticity. These memories may be highly extinction resistant and influence psychoactive drug consumption, in particular during initial establishment and at the transition to “drug instrumentalization.” In that, understanding how addictive drugs interact with episodic memory circuits in the brain may provide crucial information for how drug use and addiction are established. PMID:23734106

Episodic memories and their relevance for psychoactive drug use and addiction.

PubMed

Müller, Christian P

2013-01-01

The majority of adult people in western societies regularly consume psychoactive drugs. While this consumption is integrated in everyday life activities and controlled in most consumers, it may escalate and result in drug addiction. Non-addicted drug use requires the systematic establishment of highly organized behaviors, such as drug-seeking and -taking. While a significant role for classical and instrumental learning processes is well established in drug use and abuse, declarative drug memories have largely been neglected in research. Episodic memories are an important part of the declarative memories. Here a role of episodic drug memories in the establishment of non-addicted drug use and its transition to addiction is suggested. In relation to psychoactive drug consumption, episodic drug memories are formed when a person prepares for consumption, when the drug is consumed and, most important, when acute effects, withdrawal, craving, and relapse are experienced. Episodic drug memories are one-trial memories with emotional components that can be much stronger than "normal" episodic memories. Their establishment coincides with drug-induced neuronal activation and plasticity. These memories may be highly extinction resistant and influence psychoactive drug consumption, in particular during initial establishment and at the transition to "drug instrumentalization." In that, understanding how addictive drugs interact with episodic memory circuits in the brain may provide crucial information for how drug use and addiction are established.

Unforgettable film music: The role of emotion in episodic long-term memory for music

PubMed Central

Eschrich, Susann; Münte, Thomas F; Altenmüller, Eckart O

2008-01-01

Background Specific pieces of music can elicit strong emotions in listeners and, possibly in connection with these emotions, can be remembered even years later. However, episodic memory for emotional music compared with less emotional music has not yet been examined. We investigated whether emotional music is remembered better than less emotional music. Also, we examined the influence of musical structure on memory performance. Results Recognition of 40 musical excerpts was investigated as a function of arousal, valence, and emotional intensity ratings of the music. In the first session the participants judged valence and arousal of the musical pieces. One week later, participants listened to the 40 old and 40 new musical excerpts randomly interspersed and were asked to make an old/new decision as well as to indicate arousal and valence of the pieces. Musical pieces that were rated as very positive were recognized significantly better. Conclusion Musical excerpts rated as very positive are remembered better. Valence seems to be an important modulator of episodic long-term memory for music. Evidently, strong emotions related to the musical experience facilitate memory formation and retrieval. PMID:18505596

Unforgettable film music: the role of emotion in episodic long-term memory for music.

PubMed

Eschrich, Susann; Münte, Thomas F; Altenmüller, Eckart O

2008-05-28

Specific pieces of music can elicit strong emotions in listeners and, possibly in connection with these emotions, can be remembered even years later. However, episodic memory for emotional music compared with less emotional music has not yet been examined. We investigated whether emotional music is remembered better than less emotional music. Also, we examined the influence of musical structure on memory performance. Recognition of 40 musical excerpts was investigated as a function of arousal, valence, and emotional intensity ratings of the music. In the first session the participants judged valence and arousal of the musical pieces. One week later, participants listened to the 40 old and 40 new musical excerpts randomly interspersed and were asked to make an old/new decision as well as to indicate arousal and valence of the pieces. Musical pieces that were rated as very positive were recognized significantly better. Musical excerpts rated as very positive are remembered better. Valence seems to be an important modulator of episodic long-term memory for music. Evidently, strong emotions related to the musical experience facilitate memory formation and retrieval.

Acquired amnesia in childhood: a single case study.

PubMed

Vicari, Stefano; Menghini, Deny; Di Paola, Margherita; Serra, Laura; Donfrancesco, Alberto; Fidani, Paola; Milano, Giuseppe Maria; Carlesimo, Giovanni Augusto

2007-03-02

We report the case of C.L., an 8-year-old child who, following the surgical removal of an ependymoma from the left cerebral ventricle at the age of 4 years, developed significant difficulties in retaining day-to-day events and information. A thorough neuropsychological analysis documented in C.L. a severe anterograde amnesic syndrome, characterised by normal short-term memory, but poor performance on episodic long-term memory tests. In particular, C.L. demonstrated virtually no ability to recollect new verbal information several minutes after the presentation. As for semantic memory, C.L. demonstrated general semantic competencies, which, depending on the test, ranged from the level of a 6-year-old girl to a level corresponding to her actual chronological age. Finding a patient who, despite being severely impaired in the ability to recollect new episodic memories, still demonstrates at least partially preserved abilities to acquire new semantic knowledge suggests that neural circuits implicated in the memorisation of autobiographical events and factual information do not overlap completely. This case is examined in the light of growing literature concerned with the dissociation between episodic and semantic memory in childhood amnesia.

Personal semantics: Is it distinct from episodic and semantic memory? An electrophysiological study of memory for autobiographical facts and repeated events in honor of Shlomo Bentin.

PubMed

Renoult, Louis; Tanguay, Annick; Beaudry, Myriam; Tavakoli, Paniz; Rabipour, Sheida; Campbell, Kenneth; Moscovitch, Morris; Levine, Brian; Davidson, Patrick S R

2016-03-01

Declarative memory is thought to consist of two independent systems: episodic and semantic. Episodic memory represents personal and contextually unique events, while semantic memory represents culturally-shared, acontextual factual knowledge. Personal semantics refers to aspects of declarative memory that appear to fall somewhere in between the extremes of episodic and semantic. Examples include autobiographical knowledge and memories of repeated personal events. These two aspects of personal semantics have been studied little and rarely compared to both semantic and episodic memory. We recorded the event-related potentials (ERPs) of 27 healthy participants while they verified the veracity of sentences probing four types of questions: general (i.e., semantic) facts, autobiographical facts, repeated events, and unique (i.e., episodic) events. Behavioral results showed equivalent reaction times in all 4 conditions. True sentences were verified faster than false sentences, except for unique events for which no significant difference was observed. Electrophysiological results showed that the N400 (which is classically associated with retrieval from semantic memory) was maximal for general facts and the LPC (which is classically associated with retrieval from episodic memory) was maximal for unique events. For both ERP components, the two personal semantic conditions (i.e., autobiographical facts and repeated events) systematically differed from semantic memory. In addition, N400 amplitudes also differentiated autobiographical facts from unique events. Autobiographical facts and repeated events did not differ significantly from each other but their corresponding scalp distributions differed from those associated with general facts. Our results suggest that the neural correlates of personal semantics can be distinguished from those of semantic and episodic memory, and may provide clues as to how unique events are transformed to semantic memory. Copyright © 2015 Elsevier Ltd. All rights reserved.

Memory loss in Alzheimer's disease: implications for development of therapeutics

PubMed Central

Gold, Carl A; Budson, Andrew E

2009-01-01

Alzheimer's disease (AD) is a progressive neurodegenerative disease marked by a constellation of cognitive disturbances, the earliest and most prominent being impaired episodic memory. Episodic memory refers to the memory system that allows an individual to consciously retrieve a previously experienced item or episode of life. Many recent studies have focused on characterizing how AD pathology impacts particular aspects of episodic memory and underlying mental and neural processes. This review summarizes the findings of those studies and discusses the effects of current and promising treatments for AD on episodic memory. The goal of this review is to raise awareness of the strides that cognitive neuroscientists have made in understanding intact and dysfunctional memory. Knowledge of the specific memorial processes that are impaired in AD may be of great value to basic scientists developing novel therapies and to clinical researchers assessing the efficacy of those therapies. PMID:19086882

Noninvasive stimulation of prefrontal cortex strengthens existing episodic memories and reduces forgetting in the elderly

PubMed Central

Sandrini, Marco; Brambilla, Michela; Manenti, Rosa; Rosini, Sandra; Cohen, Leonardo G.; Cotelli, Maria

2014-01-01

Memory consolidation is a dynamic process. Reactivation of consolidated memories by a reminder triggers reconsolidation, a time-limited period during which existing memories can be modified (i.e., weakened or strengthened). Episodic memory refers to our ability to recall specific past events about what happened, including where and when. Difficulties in this form of long-term memory commonly occur in healthy aging. Because episodic memory is critical for daily life functioning, the development of effective interventions to reduce memory loss in elderly individuals is of great importance. Previous studies in young adults showed that the dorsolateral prefrontal cortex (DLPFC) plays a causal role in strengthening of verbal episodic memories through reconsolidation. The aim of the present study was to explore the extent to which facilitatory transcranial direct current stimulation (anodal tDCS) over the left DLPFC would strengthen existing episodic memories through reconsolidation in elderly individuals. On Day 1, older adults learned a list of 20 words. On Day 2 (24 h later), they received a reminder or not, and after 10 min tDCS was applied over the left DLPFC. Memory recall was tested on Day 3 (48 h later) and Day 30 (1 month later). Surprisingly, anodal tDCS over the left DLPFC (i.e., with or without the reminder) strengthened existing verbal episodic memories and reduced forgetting compared to sham stimulation. These results provide a framework for testing the hypothesis that facilitatory tDCS of left DLPFC might strengthen existing episodic memories and reduce memory loss in older adults with amnestic mild cognitive impairment. PMID:25368577

Older adults get episodic memory boosting from noninvasive stimulation of prefrontal cortex during learning.

PubMed

Sandrini, Marco; Manenti, Rosa; Brambilla, Michela; Cobelli, Chiara; Cohen, Leonardo G; Cotelli, Maria

2016-03-01

Episodic memory displays the largest degree of age-related decline, a process that is accelerated in pathological conditions such as amnestic mild cognitive impairment and Alzheimer's disease. Previous studies have shown that the left lateral prefrontal cortex (PFC) contributes to the encoding of episodic memories along the life span. The aim of this randomized, double-blind, placebo-controlled study was to test the hypothesis that anodal trascranial direct current stimulation (tDCS) over the left lateral PFC during the learning phase would enhance delayed recall of verbal episodic memories in elderly individuals. Older adults learned a list of words while receiving anodal or placebo (sham) tDCS. Memory recall was tested 48 hours and 1 month later. The results showed that anodal tDCS strengthened episodic memories, an effect indicated by enhanced delayed recall (48 hours) compared to placebo stimulation (Cohen's d effect size = 1.01). The observation that PFC-tDCS during learning can boost verbal episodic memory in the elderly opens up the possibility to design-specific neurorehabilitation protocols targeted to conditions that affect episodic memory such as mild cognitive impairment. Copyright © 2016 Elsevier Inc. All rights reserved.

Cognitive Processes Supporting Episodic Memory Formation in Childhood: The Role of Source Memory, Binding, and Executive Functioning

ERIC Educational Resources Information Center

Raj, Vinaya; Bell, Martha Ann

2010-01-01

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…

Sex differences in episodic memory in early midlife: impact of reproductive aging.

PubMed

Rentz, Dorene M; Weiss, Blair K; Jacobs, Emily G; Cherkerzian, Sara; Klibanski, Anne; Remington, Anne; Aizley, Harlyn; Goldstein, Jill M

2017-04-01

Few have characterized cognitive changes with age as a function of menopausal stage relative to men, or sex differences in components of memory in early midlife. The study aim was to investigate variation in memory function in early midlife as a function of sex, sex steroid hormones, and reproductive status. A total of 212 men and women aged 45 to 55 were selected for this cross-sectional study from a prenatal cohort of pregnancies whose mothers were originally recruited in 1959 to 1966. They underwent clinical and cognitive testing and hormonal assessments of menopause status. Multivariate general linear models for multiple memory outcomes were used to test hypotheses controlling for potential confounders. Episodic memory, executive function, semantic processing, and estimated verbal intelligence were assessed. Associative memory and episodic verbal memory were assessed using Face-Name Associative Memory Exam (FNAME) and Selective Reminding Test (SRT), given increased sensitivity to detecting early cognitive decline. Impacts of sex and reproductive stage on performance were tested. Women outperformed men on all memory measures including FNAME (β = -0.30, P < 0.0001) and SRT (β = -0.29, P < 0.0001). Furthermore, premenopausal and perimenopausal women outperformed postmenopausal women on FNAME (initial learning, β= 0.32, P = 0.01) and SRT (recall, β= 2.39, P = 0.02). Across all women, higher estradiol was associated with better SRT performance (recall, β = 1.96, P = 0.01) and marginally associated with FNAME (initial learning, β = 0.19, P = 0.06). This study demonstrated that, in early midlife, women outperformed age-matched men across all memory measures, but sex differences were attenuated for postmenopausal women. Initial learning and memory retrieval were particularly vulnerable, whereas memory consolidation and storage were preserved. Findings underscore the significance of the decline in ovarian estradiol production in midlife and its role in shaping memory function.

Autobiographical memory and well-being in aging: The central role of semantic self-images.

PubMed

Rathbone, Clare J; Holmes, Emily A; Murphy, Susannah E; Ellis, Judi A

2015-05-01

Higher levels of well-being are associated with longer life expectancies and better physical health. Previous studies suggest that processes involving the self and autobiographical memory are related to well-being, yet these relationships are poorly understood. The present study tested 32 older and 32 younger adults using scales measuring well-being and the affective valence of two types of autobiographical memory: episodic autobiographical memories and semantic self-images. Results showed that valence of semantic self-images, but not episodic autobiographical memories, was highly correlated with well-being, particularly in older adults. In contrast, well-being in older adults was unrelated to performance across a range of standardised memory tasks. These results highlight the role of semantic self-images in well-being, and have implications for the development of therapeutic interventions for well-being in aging. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Theta-burst microstimulation in the human entorhinal area improves memory specificity.

PubMed

Titiz, Ali S; Hill, Michael R H; Mankin, Emily A; M Aghajan, Zahra; Eliashiv, Dawn; Tchemodanov, Natalia; Maoz, Uri; Stern, John; Tran, Michelle E; Schuette, Peter; Behnke, Eric; Suthana, Nanthia A; Fried, Itzhak

2017-10-24

The hippocampus is critical for episodic memory, and synaptic changes induced by long-term potentiation (LTP) are thought to underlie memory formation. In rodents, hippocampal LTP may be induced through electrical stimulation of the perforant path. To test whether similar techniques could improve episodic memory in humans, we implemented a microstimulation technique that allowed delivery of low-current electrical stimulation via 100 μm -diameter microelectrodes. As thirteen neurosurgical patients performed a person recognition task, microstimulation was applied in a theta-burst pattern, shown to optimally induce LTP. Microstimulation in the right entorhinal area during learning significantly improved subsequent memory specificity for novel portraits; participants were able both to recognize previously-viewed photos and reject similar lures. These results suggest that microstimulation with physiologic level currents-a radical departure from commonly used deep brain stimulation protocols-is sufficient to modulate human behavior and provides an avenue for refined interrogation of the circuits involved in human memory.

Worrying about the Future: An Episodic Specificity Induction Impacts Problem Solving, Reappraisal, and Well-Being

PubMed Central

Jing, Helen G.; Madore, Kevin P.; Schacter, Daniel L.

2015-01-01

Previous research has demonstrated that an episodic specificity induction – brief training in recollecting details of a recent experience – enhances performance on various subsequent tasks thought to draw upon episodic memory processes. Existing work has also shown that mental simulation can be beneficial for emotion regulation and coping with stressors. Here we focus on understanding how episodic detail can affect problem solving, reappraisal, and psychological well-being regarding worrisome future events. In Experiment 1, an episodic specificity induction significantly improved participants’ performance on a subsequent means-end problem solving task (i.e., more relevant steps) and an episodic reappraisal task (i.e., more episodic details) involving personally worrisome future events compared with a control induction not focused on episodic specificity. Imagining constructive behaviors with increased episodic detail via the specificity induction was also related to significantly larger decreases in anxiety, perceived likelihood of a bad outcome, and perceived difficulty to cope with a bad outcome, as well as larger increases in perceived likelihood of a good outcome and indicated use of active coping behaviors compared with the control. In Experiment 2, we extended these findings using a more stringent control induction, and found preliminary evidence that the specificity induction was related to an increase in positive affect and decrease in negative affect compared with the control. Our findings support the idea that episodic memory processes are involved in means-end problem solving and episodic reappraisal, and that increasing the episodic specificity of imagining constructive behaviors regarding worrisome events may be related to improved psychological well-being. PMID:26820166

The Category Cued Recall test in very mild Alzheimer's disease: discriminative validity and correlation with semantic memory functions.

PubMed

Vogel, A; Mortensen, E L; Gade, A; Waldemar, G

2007-01-01

Episodic memory tests that measure cued recall may be particularly effective in the diagnosis of early Alzheimer's disease (AD) because they examine both episodic and semantic memory functions. The Category Cued Recall (CCR) test provides superordinate semantic cues at encoding and retrieval, and high discriminative validity has been claimed for this test. The aim of this study was to investigate the discriminative validity for this test when compared with the 10-word memory list from Alzheimer's Disease Assessment Scale (ADAS-cog) that measures free recall. The clinical diagnosis of AD was taken as the standard. It was also investigated whether the two episodic memory tests correlated with measures of semantic memory. The tests were administered to 35 patients with very mild AD (Mini Mental State Examination score >22) and 28 control subjects. Both tests had high sensitivity (>88%) with high specificity (>89%). One out of the five semantic memory tests was significantly correlated to performances on CCR, whereas delayed recall on the ADAS-cog memory test was significantly correlated to two semantic tests. In conclusion, the discriminative validity of the CCR test and the ADAS-cog memory test was equivalent in very mild AD. This may be because CCR did not tap more semantic processes, which are impaired in the earliest phases of AD, than a test of free recall.

How Limited Systematicity Emerges: A Computational Cognitive Neuroscience Approach (Author’s Manuscript)

DTIC Science & Technology

2014-09-01

not losing track of the original facts of the situation. However, hippocampal episodic memory also has limitations – it operates one memory at a...ability to strategically control the use of episodic memory . Specific areas of PFC are implicated as these episodic control structures, including...certainly start by encoding the problem into hippocampal episodic memory , so they can retrieve it when interference overtakes the system and they

Binding, relational memory, and recall of naturalistic events: a developmental perspective.

PubMed

Sluzenski, Julia; Newcombe, Nora S; Kovacs, Stacie L

2006-01-01

This research was an investigation of children's performance on a task that requires memory binding. In Experiments 1 and 2, 4-year-olds, 6-year-olds, and adults viewed complex pictures and were tested on memory for isolated parts in the pictures and on the part combinations (combination condition). The results suggested improvement in memory for the combinations between the ages of 4 and 6 years but not in memory for the isolated parts. In Experiments 2 and 3, the authors also examined the developmental relationship between performance in the combination condition and free recall of a naturalistic event, finding preliminary evidence that performance on a memory task that requires binding is positively related to performance in episodic memory. ((c) 2006 APA, all rights reserved).

Online assessment of risk factors for dementia and cognitive function in healthy adults.

PubMed

Huntley, J; Corbett, A; Wesnes, K; Brooker, H; Stenton, R; Hampshire, A; Ballard, C

2018-02-01

Several potentially modifiable risk factors for cognitive decline and dementia have been identified, including low educational attainment, smoking, diabetes, physical inactivity, hypertension, midlife obesity, depression, and perceived social isolation. Managing these risk factors in late midlife and older age may help reduce the risk of dementia; however, it is unclear whether these factors also relate to cognitive performance in older individuals without dementia. Data from 14 201 non-demented individuals aged >50 years who enrolled in the online PROTECT study were used to examine the relationship between cognitive function and known modifiable risk factors for dementia. Multivariate regression analyses were conducted on 4 cognitive outcomes assessing verbal and spatial working memory, visual episodic memory, and verbal reasoning. Increasing age was associated with reduced performance across all tasks. Higher educational achievement, the presence of a close confiding relationship, and moderate alcohol intake were associated with benefits across all 4 cognitive tasks, and exercise was associated with better performance on verbal reasoning and verbal working memory tasks. A diagnosis of depression was negatively associated with performance on visual episodic memory and working memory tasks, whereas being underweight negatively affected performance on all tasks apart from verbal working memory. A history of stroke was negatively associated with verbal reasoning and working memory performance. Known modifiable risk factors for dementia are associated with cognitive performance in non-demented individuals in late midlife and older age. This provides further support for public health interventions that seek to manage these risk factors across the lifespan. Copyright © 2017 John Wiley & Sons, Ltd.

The effects of the soluble guanylate cyclase stimulator riociguat on memory performance in healthy volunteers with a biperiden-induced memory impairment.

PubMed

Borghans, Laura G J M; Sambeth, Anke; Prickaerts, Jos; Ramaekers, Johannes G; Blokland, Arjan

2018-06-07

After stimulation with nitric oxide, soluble guanylate cyclase (sGC) produces cyclic guanosine monophosphate (cGMP), which stimulates an important signalling pathway for long-term potentiation (LTP). By upregulating cGMP, LTP could be stimulated and thereby enhancing memory processes. The present study investigated the effects of the sGC stimulator riociguat on cognition in healthy volunteers. Participants were pre-treated with and without biperiden, which impairs memory performance, to investigate the memory-enhancing effects of riociguat. Twenty volunteers participated in a double-blind placebo-controlled six-way crossover design with a cognitive test battery including the verbal learning task (VLT), n-back task, spatial memory test, the attention network test, and a reaction time task. Treatments were placebo and riociguat 0.5 mg, placebo and riociguat 1.0 mg, biperiden 2.0 mg and placebo, biperiden 2.0 mg and riociguat 0.5 mg and biperiden 2.0 mg and riociguat 1.0 mg. Blood pressure was found to be decreased and heart rate to be increased after administration of riociguat. Cognitive performance was not enhanced after administration of riociguat. Biperiden decreased episodic memory on the VLT, yet this deficit was not reversed by riociguat. This supports the notion that biperiden might be a valuable pharmacological model to induce episodic memory impairments as observed in AD/MCI.

Brain computer interface to enhance episodic memory in human participants

PubMed Central

Burke, John F.; Merkow, Maxwell B.; Jacobs, Joshua; Kahana, Michael J.

2015-01-01

Recent research has revealed that neural oscillations in the theta (4–8 Hz) and alpha (9–14 Hz) bands are predictive of future success in memory encoding. Because these signals occur before the presentation of an upcoming stimulus, they are considered stimulus-independent in that they correlate with enhanced memory encoding independent of the item being encoded. Thus, such stimulus-independent activity has important implications for the neural mechanisms underlying episodic memory as well as the development of cognitive neural prosthetics. Here, we developed a brain computer interface (BCI) to test the ability of such pre-stimulus activity to modulate subsequent memory encoding. We recorded intracranial electroencephalography (iEEG) in neurosurgical patients as they performed a free recall memory task, and detected iEEG theta and alpha oscillations that correlated with optimal memory encoding. We then used these detected oscillatory changes to trigger the presentation of items in the free recall task. We found that item presentation contingent upon the presence of pre-stimulus theta and alpha oscillations modulated memory performance in more sessions than expected by chance. Our results suggest that an electrophysiological signal may be causally linked to a specific behavioral condition, and contingent stimulus presentation has the potential to modulate human memory encoding. PMID:25653605

The ERP correlates of self-knowledge: Are assessments of one's past, present, and future traits closer to semantic or episodic memory?

PubMed

Tanguay, Annick N; Benton, Lauren; Romio, Lorenza; Sievers, Carolin; Davidson, Patrick S R; Renoult, Louis

2018-02-01

Self-knowledge concerns one's own preferences and personality. It pertains to the self (similar to episodic memory), yet does not concern events. It is factual (like semantic memory), but also idiosyncratic. For these reasons, it is unclear where self-knowledge might fall on a continuum in relation to semantic and episodic memory. In this study, we aimed to compare the event-related potential (ERP) correlates of self-knowledge to those of semantic and episodic memory, using N400 and Late Positive Component (LPC) as proxies for semantic and episodic processing, respectively. We considered an additional factor: time perspective. Temporally distant selves have been suggested to be more semantic compared to the present self, but thinking about one's past and future selves may also engage episodic memory. Twenty-eight adults answered whether traits (e.g., persistent) were true of most people holding an occupation (e.g., soldiers; semantic memory condition), or true of themselves 5 years ago, in the present, or 5 years from now (past, present, and future self-knowledge conditions). The study ended with an episodic recognition memory task for previously seen traits. Present self-knowledge produced mean LPC amplitudes at posterior parietal sites that fell between semantic and episodic memory. Mean LPC amplitudes for past and future self-knowledge were greater than for semantic memory, and not significantly different from episodic memory. Mean N400 amplitudes for the self-knowledge conditions were smaller than for semantic memory at sagittal sites. However, this N400 effect was not separable from a preceding P200 effect at these same electrode sites. This P200 effect can be interpreted as reflecting the greater emotional salience of self as compared to general knowledge, which may have facilitated semantic processing. Overall, our findings are consistent with a distinction between knowledge of others and self-knowledge, but the closeness of self-knowledge's neural correlates to either semantic or episodic memory appears to depend to some extent on time perspective. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neuropsychological assessment of memory in child and adolescent first episode psychosis: cannabis and «the paradox effect».

PubMed

Moreno-Granados, Josefa María; Ferrín, Maite; Salcedo-Marín, Dolores M; Ruiz-Veguilla, Miguel

2014-01-01

The importance of neuropsychological functioning in First-Episode Psychosis (FEP) has led to the publication of a growing number of studies in this area of research. The present study pursued three goals: First, to examine verbal and visual memory in a sample of Child and Adolescent FEP, second, to evaluate the effect of other cognitive domains on verbal and visual memory, and finally, to examine the relationship between performance in this cognitive dimension and the use of cannabis at this age. A sample of 41 FEPs and 39 healthy subjects were evaluated. The variables assessed were verbal and visual memory, attention, working memory, processing speed, mental flexibility, verbal fluency, motor coordination, planning ability and intelligence. Our results found impairment of short and long-term recall of verbal memory, and short-term visual memory in early psychosis. They also found relationships between cognitive dimensions, such as visual memory and intelligence and motor coordination. Finally, a «paradoxical» effect was found in patients who used cannabis, as the FEP consumers performed the visual memory test better than those who had not used it. Patients showed impairment of short and long-term recall of verbal information and short-term visual reproduction. In the second place, motor coordination and intelligence influenced short-term visual memory in patients in the early stages of the illness. Third, use of cannabis in patients with FEP was associated with better performance in the test that evaluated the short-term visual memory, as measured by task completion time, that is, efficiency in performing the test. However, when measured by task execution accuracy, their visual memory was no better than the controls. Copyright © 2012 SEP y SEPB. Published by Elsevier España. All rights reserved.

Thinking about the future can cause forgetting of the past.

PubMed

Ditta, Annie S; Storm, Benjamin C

2016-01-01

People are able to imagine events in the future that have not yet happened, an ability referred to as episodic future thinking. There is now compelling evidence that episodic future thinking is accomplished via processes similar to those that underlie episodic retrieval. Drawing upon work on retrieval-induced forgetting, which has shown that retrieving some items in memory can cause the forgetting of other items in memory, we show that engaging in episodic future thinking can cause related autobiographical memories (Experiments 1-3) and episodic event descriptions (Experiments 3-4) to become less recallable in the future than they would have been otherwise. This finding suggests that episodic future thinking can serve as a memory modifier by changing the extent to which memories from our past can be subsequently retrieved.

MRI-leukoaraiosis thresholds and the phenotypic expression of dementia

PubMed Central

Mitchell, Sandra M.; Brumback, Babette; Tanner, Jared J.; Schmalfuss, Ilona; Lamar, Melissa; Giovannetti, Tania; Heilman, Kenneth M.; Libon, David J.

2012-01-01

Objective: To examine the concept of leukoaraiosis thresholds on working memory, visuoconstruction, memory, and language in dementia. Methods: A consecutive series of 83 individuals with insidious onset/progressive dementia clinically diagnosed with Alzheimer disease (AD) or small vessel vascular dementia (VaD) completed neuropsychological measures assessing working memory, visuoconstruction, episodic memory, and language. A clinical MRI scan was used to quantify leukoaraiosis, total white matter, hippocampus, lacune, and intracranial volume. We performed analyses to detect the lowest level of leukoaraiosis associated with impairment on the neuropsychological measures. Results: Leukoaraiosis ranged from 0.63% to 23.74% of participants' white matter. Leukoaraiosis explained a significant amount of variance in working memory performance when it involved 3% or more of the white matter with curve estimations showing the relationship to be nonlinear in nature. Greater leukoaraiosis (13%) was implicated for impairment in visuoconstruction. Relationships between leukoaraiosis, episodic memory, and language measures were linear or flat. Conclusions: Leukoaraiosis involves specific threshold points for working memory and visuoconstructional tests in AD/VaD spectrum dementia. These data underscore the need to better understand the threshold at which leukoaraiosis affects and alters the phenotypic expression in insidious onset dementia syndromes. PMID:22843264

Episodic and Semantic Memory: Implications for the Role of Emotion in Advertising.

ERIC Educational Resources Information Center

Thorson, Esther

In an examination of the way people store and retrieve information from advertising, this paper draws a distinction between "semantic" memory, which stores general knowledge about the world, and "episodic" memory, which stores information about specific events. It then argues that episodic memory plays a more significant role…

Developmental roots of episodic memory.

PubMed

Nelson, Katherine

2018-01-01

Two arguments imply that Mahr & Csibra's (M&C's) functional theory is insufficient as an explanation of episodic memory: (1) The developmental course supports a different social cultural division of episodic and semantic memory, and (2) the existence of long-term autobiographical memory is not explained in the functional theory but can be seen in a broader cultural framework.

Intrusions in Episodic Memory: Reconsolidation or Interference?

ERIC Educational Resources Information Center

Klingmüller, Angela; Caplan, Jeremy B.; Sommer, Tobias

2017-01-01

It would be profoundly important if reconsolidation research in animals and other memory domains generalized to human episodic memory. A 3-d-list-discrimination procedure, based on free recall of objects, with a contextual reminder cue (the testing room), has been thought to demonstrate reconsolidation of human episodic memory (as noted in a…

Memory Transformation Enhances Reinforcement Learning in Dynamic Environments.

PubMed

Santoro, Adam; Frankland, Paul W; Richards, Blake A

2016-11-30

Over the course of systems consolidation, there is a switch from a reliance on detailed episodic memories to generalized schematic memories. This switch is sometimes referred to as "memory transformation." Here we demonstrate a previously unappreciated benefit of memory transformation, namely, its ability to enhance reinforcement learning in a dynamic environment. We developed a neural network that is trained to find rewards in a foraging task where reward locations are continuously changing. The network can use memories for specific locations (episodic memories) and statistical patterns of locations (schematic memories) to guide its search. We find that switching from an episodic to a schematic strategy over time leads to enhanced performance due to the tendency for the reward location to be highly correlated with itself in the short-term, but regress to a stable distribution in the long-term. We also show that the statistics of the environment determine the optimal utilization of both types of memory. Our work recasts the theoretical question of why memory transformation occurs, shifting the focus from the avoidance of memory interference toward the enhancement of reinforcement learning across multiple timescales. As time passes, memories transform from a highly detailed state to a more gist-like state, in a process called "memory transformation." Theories of memory transformation speak to its advantages in terms of reducing memory interference, increasing memory robustness, and building models of the environment. However, the role of memory transformation from the perspective of an agent that continuously acts and receives reward in its environment is not well explored. In this work, we demonstrate a view of memory transformation that defines it as a way of optimizing behavior across multiple timescales. Copyright © 2016 the authors 0270-6474/16/3612228-15$15.00/0.

Differential effects of acute cortisol administration on deep and shallow episodic memory traces: a study on healthy males.

PubMed

Cioncoloni, David; Galli, Giulia; Mazzocchio, Riccardo; Feurra, Matteo; Giovannelli, Fabio; Santarnecchi, Emiliano; Bonifazi, Marco; Rossi, Alessandro; Rossi, Simone

2014-10-01

We aimed at investigating rapid effects of plasma cortisol elevations on the episodic memory phase of encoding or retrieval, and on the strength of the memory trace. Participants were asked either to select a word containing the letter "e" (shallow encoding task) or to judge if a word referred to a living entity (deep encoding task). We intravenously administered a bolus of 20mg of cortisol either 5 min before encoding or 5 min before retrieval, in a between-subjects design. The study included only male participants tested in the late afternoon, and neutral words as stimuli. When cortisol administration occurred prior to retrieval, a main effect of group emerged. Recognition accuracy was higher for individuals who received cortisol compared to placebo. The higher discrimination accuracy for the cortisol group was significant for words encoded during deep but not shallow task. Cortisol administration before encoding did not affect subsequent retrieval performance (either for deep or shallow stimuli) despite a facilitatory trend. Because genomic mechanisms take some time to develop, such a mechanism cannot apply to our findings where the memory task was performed shortly after the enhancement of glucocorticoid levels. Therefore, glucocorticoids, through non-genomic fast effects, determine an enhancement in episodic memory if administered immediately prior to retrieval. This effect is more evident if the memory trace is laid down through deep encoding operations involving the recruitment of specific neural networks. Copyright © 2014 Elsevier Inc. All rights reserved.

Lower cognitive performance among long-term type 1 diabetes survivors: A case-control study.

PubMed

Awad, Anna; Lundqvist, Robert; Rolandsson, Olov; Sundström, Anna; Eliasson, Mats

2017-08-01

Patients with type 1 diabetes (T1D) have an increased risk of cognitive dysfunction. The cognitive decrement is believed to depend on macro- and microvascular complications and long disease duration. Some patients do not develop these complications, but still report cognitive symptoms. We examined if long-standing T1D without complications is associated with lower cognitive performance. A group of patients (n=43) with long-standing T1D (>30years) without micro- or macro vascular complications was compared with a non-diabetic control group (n=86) on six cognitive tests which probed episodic memory, semantic memory, episodic short-term memory, visual attention and psychomotor speed. Each patient was matched with two controls regarding age, gender and education. A linear mixed effect model was used to analyze the data. The mean age was 57years and mean duration was 41years. Patients with diabetes had lower diastolic blood pressure but BMI, waist circumference, systolic blood pressure and smoking did not differ between groups. Patients had lower results than non-diabetic controls in episodic short-term memory (p<0.001) and also lower values on a test that mirrors visual attention and psychomotor speed (p=0.019). Long-standing T1D was associated with lower cognitive performance, regardless of other diabetes-related complications. Copyright © 2017 Elsevier Inc. All rights reserved.

Verbal episodic memory in 426 multiple sclerosis patients: impairment in encoding, retrieval or both?

PubMed

Brissart, H; Morele, E; Baumann, C; Debouverie, M

2012-10-01

Episodic memory is frequently impaired in multiple sclerosis (MS) patients but the exact nature of the disorder is controversial. It was initially thought to be due to a retrieval deficit but some studies have demonstrated an encoding deficit, which could be linked to a slowing of information processing speed or to a deficit in elaboration of strategies. The main objective of this study is to assess the prevalence and the nature of verbal episodic memory (VEM) impairment in MS patients. We retrieved memory performances of 426 patients [314 F-112 M; mean age: 46.1 years; median Expanded Disability Status Scale (EDSS) score: 3.1] from a neuropsychological data base. VEM was assessed using the 16 words RL-RI 16 test. 66% MS patients present at least one recall impaired in VEM (37.2% from 2 to 5 recall). 14.2% MS patients present an impairment in encoding phase. We observed that 5% of patients presented recognition difficulties. Correlations were observed between VEM performances and EDSS, and disease duration but no group effect (ANOVA) is observed between form of MS and VEM performances. These results confirm the high prevalence of VEM impairment in MS patients. Deficits affect mainly information retrieval in early stage MS patients and are then linked to encoding as disability increases. Storage disorders are infrequent, so cognitive rehabilitation with mental imaging could be effective in MS patients.

Posterior parietal cortex and episodic encoding: insights from fMRI subsequent memory effects and dual-attention theory.

PubMed

Uncapher, Melina R; Wagner, Anthony D

2009-02-01

The formation of episodic memories--memories for life events--is affected by attention during event processing. A leading neurobiological model of attention posits two separate yet interacting systems that depend on distinct regions in lateral posterior parietal cortex (PPC). From this dual-attention perspective, dorsal PPC is thought to support the goal-directed allocation of attention, whereas ventral PPC is thought to support reflexive orienting to information that automatically captures attention. To advance understanding of how parietal mechanisms may impact event encoding, we review functional MRI studies that document the relationship between lateral PPC activation during encoding and subsequent memory performance (e.g., later remembering or forgetting). This review reveals that (a) encoding-related activity is frequently observed in human lateral PPC, (b) increased activation in dorsal PPC is associated with later memory success, and (c) increased activation in ventral PPC predominantly correlates with later memory failure. From a dual-attention perspective, these findings suggest that allocating goal-directed attention during event processing increases the probability that the event will be remembered later, whereas the capture of reflexive attention during event processing may have negative consequences for event encoding. The prevalence of encoding-related activation in parietal cortex suggests that neurobiological models of episodic memory should consider how parietal-mediated attentional mechanisms regulate encoding.

Impact of emotional salience on episodic memory in attention-deficit/hyperactivity disorder: a functional magnetic resonance imaging study.

PubMed

Krauel, Kerstin; Duzel, Emrah; Hinrichs, Hermann; Santel, Stephanie; Rellum, Thomas; Baving, Lioba

2007-06-15

Patients with attention-deficit/hyperactivity disorder (ADHD) show episodic memory deficits especially in complex memory tasks. We investigated the neural correlates of memory formation in ADHD and their modulation by stimulus salience. We recorded event-related functional magnetic resonance imaging during an episodic memory paradigm with neutral and emotional pictures in 12 male ADHD subjects and 12 healthy adolescents. Emotional salience did significantly augment memory performance in ADHD patients. Successful encoding of neutral pictures was associated with activation of the anterior cingulate cortex (ACC) in healthy adolescents but with activation of the superior parietal lobe (SPL) and precuneus in ADHD patients. Successful encoding of emotional pictures was associated with prefrontal and inferior temporal cortex activation in both groups. Healthy adolescents, moreover, showed deactivation in the inferior parietal lobe. From a pathophysiological point of view, the most striking functional differences between healthy adolescents and ADHD patients were in the ACC and SPL. We suggest that increased SPL activation in ADHD reflected attentional compensation for low ACC activation during the encoding of neutral pictures. The higher salience of emotional stimuli, in contrast, regulated the interplay between ACC and SPL in conjunction with improving memory to the level of healthy adolescents.

Using Virtual Reality to Characterize Episodic Memory Profiles in Amnestic Mild Cognitive Impairment and Alzheimer's Disease: Influence of Active and Passive Encoding

ERIC Educational Resources Information Center

Plancher, G.; Tirard, A.; Gyselinck, V.; Nicolas, S.; Piolino, P.

2012-01-01

Most neuropsychological assessments of episodic memory bear little similarity to the events that patients actually experience as memories in daily life. The first aim of this study was to use a virtual environment to characterize episodic memory profiles in an ecological fashion, which includes memory for central and perceptual details,…

Comparative Cognition: Action Imitation Using Episodic Memory.

PubMed

Crystal, Jonathon D

2016-12-05

Humans encounter a myriad of actions or events and later recall some of these events using episodic memory. New research suggests that dogs can imitate recently encountered actions using episodic memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

Episodic and semantic content of memory and imagination: A multilevel analysis.

PubMed

Devitt, Aleea L; Addis, Donna Rose; Schacter, Daniel L

2017-10-01

Autobiographical memories of past events and imaginations of future scenarios comprise both episodic and semantic content. Correlating the amount of "internal" (episodic) and "external" (semantic) details generated when describing autobiographical events can illuminate the relationship between the processes supporting these constructs. Yet previous studies performing such correlations were limited by aggregating data across all events generated by an individual, potentially obscuring the underlying relationship within the events themselves. In the current article, we reanalyzed datasets from eight studies using a multilevel approach, allowing us to explore the relationship between internal and external details within events. We also examined whether this relationship changes with healthy aging. Our reanalyses demonstrated a largely negative relationship between the internal and external details produced when describing autobiographical memories and future imaginations. This negative relationship was stronger and more consistent for older adults and was evident both in direct and indirect measures of semantic content. Moreover, this relationship appears to be specific to episodic tasks, as no relationship was observed for a nonepisodic picture description task. This negative association suggests that people do not generate semantic information indiscriminately, but do so in a compensatory manner, to embellish episodically impoverished events. Our reanalysis further lends support for dissociable processes underpinning episodic and semantic information generation when remembering and imagining autobiographical events.

Counterfactual thinking: an fMRI study on changing the past for a better future

PubMed Central

Ma, Ning; Ampe, Lisa; Baetens, Kris; Van Overwalle, Frank

2013-01-01

Recent studies suggest that a brain network mainly associated with episodic memory has a more general function in imagining oneself in another time, place or perspective (e.g. episodic future thought, theory of mind, default mode). If this is true, counterfactual thinking (e.g. ‘If I had left the office earlier, I wouldn’t have missed my train.’) should also activate this network. Present functional magnetic resonance imaging (fMRI) study explores the common and distinct neural activity of counterfactual and episodic thinking by directly comparing the imagining of upward counterfactuals (creating better outcomes for negative past events) with the re-experiencing of negative past events and the imagining of positive future events. Results confirm that episodic and counterfactual thinking share a common brain network, involving a core memory network (hippocampal area, temporal lobes, midline, and lateral parietal lobes) and prefrontal areas that might be related to mentalizing (medial prefrontal cortex) and performance monitoring (right prefrontal cortex). In contrast to episodic past and future thinking, counterfactual thinking recruits some of these areas more strongly and extensively, and additionally activates the bilateral inferior parietal lobe and posterior medial frontal cortex. We discuss these findings in view of recent fMRI evidence on the working of episodic memory and theory of mind. PMID:22403155

To Switch or Not to Switch: Role of Cognitive Control in Working Memory Training in Older Adults.

PubMed

Basak, Chandramallika; O'Connell, Margaret A

2016-01-01

It is currently not known what are the best working memory training strategies to offset the age-related declines in fluid cognitive abilities. In this randomized clinical double-blind trial, older adults were randomly assigned to one of two types of working memory training - one group was trained on a predictable memory updating task (PT) and another group was trained on a novel, unpredictable memory updating task (UT). Unpredictable memory updating, compared to predictable, requires greater demands on cognitive control (Basak and Verhaeghen, 2011a). Therefore, the current study allowed us to evaluate the role of cognitive control in working memory training. All participants were assessed on a set of near and far transfer tasks at three different testing sessions - before training, immediately after the training, and 1.5 months after completing the training. Additionally, individual learning rates for a comparison working memory task (performed by both groups) and the trained task were computed. Training on unpredictable memory updating, compared to predictable, significantly enhanced performance on a measure of episodic memory, immediately after the training. Moreover, individuals with faster learning rates showed greater gains in this episodic memory task and another new working memory task; this effect was specific to UT. We propose that the unpredictable memory updating training, compared to predictable memory updating training, may a better strategy to improve selective cognitive abilities in older adults, and future studies could further investigate the role of cognitive control in working memory training.

Neural Correlates of Verbal Episodic Memory and Lexical Retrieval in Logopenic Variant Primary Progressive Aphasia.

PubMed

Win, Khaing T; Pluta, John; Yushkevich, Paul; Irwin, David J; McMillan, Corey T; Rascovsky, Katya; Wolk, David; Grossman, Murray

2017-01-01

Objective: Logopenic variant primary progressive aphasia (lvPPA) is commonly associated with Alzheimer's disease (AD) pathology. But lvPPA patients display different cognitive and anatomical profile from the common clinical AD patients, whose verbal episodic memory is primarily affected. Reports of verbal episodic memory difficulty in lvPPA are inconsistent, and we hypothesized that their lexical retrieval impairment contributes to verbal episodic memory performance and is associated with left middle temporal gyrus atrophy. Methods: We evaluated patients with lvPPA ( n = 12) displaying prominent word-finding and repetition difficulties, and a demographically-matched cohort of clinical Alzheimer's disease (AD, n = 26), and healthy seniors ( n = 16). We assessed lexical retrieval with confrontation naming and verbal episodic memory with delayed free recall. Whole-brain regressions related naming and delayed free recall to gray matter atrophy. Medial temporal lobe (MTL) subfields were examined using high in-plane resolution imaging. Results: lvPPA patients had naming and delayed free recall impairments, but intact recognition memory. In lvPPA, delayed free recall was related to naming; both were associated with left middle temporal gyrus atrophy but not MTL atrophy. Despite cerebrospinal fluid evidence consistent with AD pathology, examination of MTL subfields revealed no atrophy in lvPPA. While AD patients displayed impaired delayed free recall, this deficit did not correlate with naming. Regression analyses related delayed free recall deficits in clinical AD patients to MTL subfield atrophy, and naming to left middle temporal gyrus atrophy. Conclusion: Unlike amnestic AD patients, MTL subfields were not affected in lvPPA patients. Verbal episodic memory deficit observed in lvPPA was unlikely to be due to a hippocampal-mediated mechanism but appeared to be due to poor lexical retrieval. Relative sparing of MTL volume and intact recognition memory are consistent with previous reports of hippocampal-sparing variant cases of AD pathology, where neurofibrillary tangles are disproportionately distributed in cortical areas with relative sparing of the hippocampus. This suggests that AD neuropathology in lvPPA may originate in neuronal networks outside of the MTL, which deviates from the typical Braak staging pattern of spreading pathology in clinical AD.

Increased Interhemispheric Interaction Is Associated with Decreased False Memories in a Verbal Converging Semantic Associates Paradigm

ERIC Educational Resources Information Center

Christman, S.D.; Propper, R.E.; Dion, A.

2004-01-01

Recent evidence indicates that task and subject variables that are associated with increased interaction between the left and right cerebral hemispheres result in enhanced performance on tests of episodic memory. The current study looked at the effects of increased interhemispheric interaction on false memories using a verbal converging semantic…

The Episodicity of Verbal Reports of Personally Significant Autobiographical Memories: Vividness Correlates with Narrative Text Quality More than with Detailedness or Memory Specificity

PubMed Central

Habermas, Tilmann; Diel, Verena

2013-01-01

How can we tell from a memory report whether a memory is episodic or not? Vividness is required by many definitions, whereas detailedness, memory specificity, and narrative text type are competing definitions of episodicity used in research. We explored their correlations with vividness in personally significant autobiographical memories to provide evidence to support their relative claim to define episodic memories. In addition, we explored differences between different memory types and text types as well as between memories with different valences. We asked a lifespan sample (N = 168) of 8-, 12-, 16-, 20-, 40-, and 65-year-olds of both genders (N = 27, 29, 27, 27, 28, 30) to provide brief oral life narratives. These were segmented into thematic memory units. Detailedness of person, place, and time did not correlate with each other or either vividness, memory specificity, or narrative text type. Narrative text type, in contrast, correlated both with vividness and memory specificity, suggesting narrative text type as a good criterion of episodicity. Emotionality turned out to be an even better predictor of vividness. Also, differences between narrative, chronicle, and argument text types and between specific versus more extended and atemporal memories were explored as well as differences between positive, negative, ambivalent, neutral, contamination, and redemption memory reports. It is concluded that temporal sequentiality is a central characteristic of episodic autobiographical memories. Furthermore, it is suggested that the textual quality of memory reports should be taken more seriously, and that evaluation and interpretation are inherent aspects of personally significant memories. PMID:23966918

Motor Phenotype of Decline in Cognitive Performance among Community-Dwellers without Dementia: Population-Based Study and Meta-Analysis

PubMed Central

Beauchet, Olivier; Allali, Gilles; Montero-Odasso, Manuel; Sejdić, Ervin; Fantino, Bruno; Annweiler, Cédric

2014-01-01

Background Decline in cognitive performance is associated with gait deterioration. Our objectives were: 1) to determine, from an original study in older community-dwellers without diagnosis of dementia, which gait parameters, among slower gait speed, higher stride time variability (STV) and Timed Up & Go test (TUG) delta time, were most strongly associated with lower performance in two cognitive domains (i.e., episodic memory and executive function); and 2) to quantitatively synthesize, with a systematic review and meta-analysis, the association between gait performance and cognitive decline (i.e., mild cognitive impairment (MCI) and dementia). Methods Based on a cross-sectional design, 934 older community-dwellers without dementia (mean±standard deviation, 70.3±4.9years; 52.1% female) were recruited. A score at 5 on the Short Mini-Mental State Examination defined low episodic memory performance. Low executive performance was defined by clock-drawing test errors. STV and gait speed were measured using GAITRite system. TUG delta time was calculated as the difference between the times needed to perform and to imagine the TUG. Then, a systematic Medline search was conducted in November 2013 using the Medical Subject Heading terms “Delirium,” “Dementia,” “Amnestic,” “Cognitive disorders” combined with “Gait” OR “Gait disorders, Neurologic” and “Variability.” Findings A total of 294 (31.5%) participants presented decline in cognitive performance. Higher STV, higher TUG delta time, and slower gait speed were associated with decline in episodic memory and executive performances (all P-values <0.001). The highest magnitude of association was found for higher STV (effect size  =  −0.74 [95% Confidence Interval (CI): −1.05;−0.43], among participants combining of decline in episodic memory and in executive performances). Meta-analysis underscored that higher STV represented a gait biomarker in patients with MCI (effect size  =  0.48 [95% CI: 0.30;0.65]) and dementia (effect size  = 1.06 [95% CI: 0.40;1.72]). Conclusion Higher STV appears to be a motor phenotype of cognitive decline. PMID:24911155

Why do we remember? The communicative function of episodic memory

PubMed Central

Mahr, Johannes B.; Csibra, Gergely

2017-01-01

Short Abstract We propose a novel account of episodic memory function based on a conceptual and empirical analysis of its role in belief formation. We provide a critique of the view that episodic memory serves future-directed imagination, and argue that the central features of this capacity can instead be explained by the role it plays in human communication. On this view, episodic memory allows us to communicatively support our interpretations of the past by gauging when we can assert epistemic authority. This capacity is ineliminable in justification of, and negotiations about, social commitments established by past interactions. Long Abstract Episodic memory has been analyzed in a number of different ways in both philosophy and psychology, and most controversy has centered on its self-referential, ‘autonoetic’ character. Here, we offer a comprehensive characterization of episodic memory in representational terms, and propose a novel functional account on this basis. We argue that episodic memory should be understood as a distinctive epistemic attitude taken towards an event simulation. On this view, episodic memory has a metarepresentational format and should not be equated with beliefs about the past. Instead, empirical findings suggest that the contents of human episodic memory are often constructed in the service of the explicit justification of such beliefs. Existing accounts of episodic memory function that have focused on explaining its constructive character through its role in ‘future-oriented mental time travel’ neither do justice to its capacity to ground veridical beliefs about the past nor to its representational format. We provide an account of the metarepresentational structure of episodic memory in terms of its role in communicative interaction. The generative nature of recollection allows us to represent and communicate the reasons for why we hold certain beliefs about the past. In this process, autonoesis corresponds to the capacity to determine when and how to assert epistemic authority in making claims about the past. A domain where such claims are indispensable are human social engagements. Such engagements commonly require the justification of entitlements and obligations, which is often possible only by explicit reference to specific past events. PMID:28100294

Sentence Verification, Sentence Recognition, and the Semantic-Episodic Distinction

ERIC Educational Resources Information Center

Shoben, Edward J.; And Others

1978-01-01

In an attempt to assess the validity of the distinction between episodic and semantic memory, this research examined the influence of two variables on sentence verification (presumably a semantic memory task) and sentence recognition (presumably an episodic memory task). ( Editor)

The CRISP theory of hippocampal function in episodic memory

PubMed Central

Cheng, Sen

2013-01-01

Over the past four decades, a “standard framework” has emerged to explain the neural mechanisms of episodic memory storage. This framework has been instrumental in driving hippocampal research forward and now dominates the design and interpretation of experimental and theoretical studies. It postulates that cortical inputs drive plasticity in the recurrent cornu ammonis 3 (CA3) synapses to rapidly imprint memories as attractor states in CA3. Here we review a range of experimental studies and argue that the evidence against the standard framework is mounting, notwithstanding the considerable evidence in its support. We propose CRISP as an alternative theory to the standard framework. CRISP is based on Context Reset by dentate gyrus (DG), Intrinsic Sequences in CA3, and Pattern completion in cornu ammonis 1 (CA1). Compared to previous models, CRISP uses a radically different mechanism for storing episodic memories in the hippocampus. Neural sequences are intrinsic to CA3, and inputs are mapped onto these intrinsic sequences through synaptic plasticity in the feedforward projections of the hippocampus. Hence, CRISP does not require plasticity in the recurrent CA3 synapses during the storage process. Like in other theories DG and CA1 play supporting roles, however, their function in CRISP have distinct implications. For instance, CA1 performs pattern completion in the absence of CA3 and DG contributes to episodic memory retrieval, increasing the speed, precision, and robustness of retrieval. We propose the conceptual theory, discuss its implications for experimental results and suggest testable predictions. It appears that CRISP not only accounts for those experimental results that are consistent with the standard framework, but also for results that are at odds with the standard framework. We therefore suggest that CRISP is a viable, and perhaps superior, theory for the hippocampal function in episodic memory. PMID:23653597

Aberrant functional connectivity in Papez circuit correlates with memory performance in cognitively intact middle-aged APOE4 carriers.

PubMed

Li, Wenjun; Antuono, Piero G; Xie, Chunming; Chen, Gang; Jones, Jennifer L; Ward, B Douglas; Singh, Suraj P; Franczak, Malgorzata B; Goveas, Joseph S; Li, Shi-Jiang

2014-08-01

The main objective of this study is to detect the early changes in resting-state Papez circuit functional connectivity using the hippocampus as the seed, and to determine the associations between altered functional connectivity (FC) and the episodic memory performance in cognitively intact middle-aged apolipoprotein E4 (APOE4) carriers who are at risk of Alzheimer's disease (AD). Forty-six cognitively intact, middle-aged participants, including 20 APOE4 carriers and 26 age-, sex-, and education-matched noncarriers were studied. The resting-state FC of the hippocampus (HFC) was compared between APOE4 carriers and noncarriers. APOE4 carriers showed significantly decreased FC in brain areas that involve learning and memory functions, including the frontal, cingulate, thalamus and basal ganglia regions. Multiple linear regression analysis showed significant correlations between HFC and the episodic memory performance. Conjunction analysis between neural correlates of memory and altered HFC showed the overlapping regions, especially the subcortical regions such as thalamus, caudate nucleus, and cingulate cortices involved in the Papez circuit. Thus, changes in connectivity in the Papez circuit may be used as an early risk detection for AD. Copyright © 2014. Published by Elsevier Ltd.

Evidence for a Specific Integrative Mechanism for Episodic Memory Mediated by AMPA/kainate Receptors in a Circuit Involving Medial Prefrontal Cortex and Hippocampal CA3 Region.

PubMed

de Souza Silva, Maria A; Huston, Joseph P; Wang, An-Li; Petri, David; Chao, Owen Yuan-Hsin

2016-07-01

We asked whether episodic-like memory requires neural mechanisms independent of those that mediate its component memories for "what," "when," and "where," and if neuronal connectivity between the medial prefrontal cortex (mPFC) and the hippocampus (HPC) CA3 subregion is essential for episodic-like memory. Unilateral lesion of the mPFC was combined with unilateral lesion of the CA3 in the ipsi- or contralateral hemispheres in rats. Episodic-like memory was tested using a task, which assesses the integration of memories for "what, where, and when" concomitantly. Tests for novel object recognition (what), object place (where), and temporal order memory (when) were also applied. Bilateral disconnection of the mPFC-CA3 circuit by N-methyl-d-aspartate (NMDA) lesions disrupted episodic-like memory, but left the component memories for object, place, and temporal order, per se, intact. Furthermore, unilateral NMDA lesion of the CA3 plus injection of (6-cyano-7-nitroquinoxaline-2,3-dione) (CNQX) (AMPA/kainate receptor antagonist), but not AP-5 (NMDA receptor antagonist), into the contralateral mPFC also disrupted episodic-like memory, indicating the mPFC AMPA/kainate receptors as critical for this circuit. These results argue for a selective neural system that specifically subserves episodic memory, as it is not critically involved in the control of its component memories for object, place, and time. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Tobacco may mask poorer episodic memory among young adult cannabis users.

PubMed

Schuster, Randi M; Crane, Natania A; Mermelstein, Robin; Gonzalez, Raul

2015-09-01

Co-occurring cannabis and tobacco use has become increasingly prevalent among young adults, but it is not clear how tobacco use may alter the neurocognitive profile typically observed among cannabis users. Although there is substantial evidence citing cannabis and tobacco's individual effect on episodic memory and related brain structures, few studies have examined the effect of combined cannabis and tobacco use on memory. This investigation examined relationships between amount of past year cannabis and tobacco use on 4 different indices of episodic memory among a sample of young adults who identified cannabis as their drug of choice. Results indicated that more cannabis use was linked with poorer initial acquisition, total learning, and delayed recall on the Hopkins Verbal Learning Test-Revised, but only among cannabis users who sporadically smoked cigarettes in the past year. Conversely, the amount of past year cannabis use was not associated with episodic memory performance among individuals who more consistently smoked cigarettes in the past year. These differences could not be explained by several relevant potential confounds. These findings provide important insight into a potential mechanism (i.e., attenuation of cognitive decrements) that might reinforce use of both substances and hamper cessation attempts among cannabis users who also smoke cigarettes. Ongoing and future research will help to better understand how co-use of cannabis and tobacco affects memory during acute intoxication and abstinence and the stability of these associations over time. (c) 2015 APA, all rights reserved).

Episodic and Semantic Autobiographical Memory in Adults with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Crane, Laura; Goddard, Lorna

2008-01-01

Episodic and semantic autobiographical memories were examined in a group of adults with autism spectrum disorders (ASD) and a control group matched for age, gender and IQ. Results demonstrated a personal episodic memory deficit in the ASD group in the absence of a personal semantic memory deficit, suggesting a deficit dissociation between these…

Episodic Autobiographical Memories over the Course of Time: Cognitive, Neuropsychological and Neuroimaging Findings

ERIC Educational Resources Information Center

Piolino, Pascale; Desgranges, Beatrice; Eustache, Francis

2009-01-01

The critical attributes of episodic memory are self, autonoetic consciousness and subjectively sensed time. The aim of this paper is to present a theoretical overview of our already published researches into the nature of episodic memory over the course of time. We have developed a new method of assessing "autobiographical" memory (TEMPau task),…

Remembering in Contradictory Minds: Disjunction Fallacies in Episodic Memory

ERIC Educational Resources Information Center

Brainerd, C. J.; Reyna, V. F.; Aydin, C.

2010-01-01

Disjunction fallacies have been extensively studied in probability judgment. They should also occur in episodic memory, if remembering a cue's episodic state depends on how its state is described on a memory test (e.g., being described as a target vs. as a distractor). If memory is description-dependent, cues will be remembered as occupying…

Gender differences in the functional neuroanatomy of emotional episodic autobiographical memory.

PubMed

Piefke, Martina; Weiss, Peter H; Markowitsch, Hans J; Fink, Gereon R

2005-04-01

Autobiographical memory is based on interactions between episodic memory contents, associated emotions, and a sense of self-continuity along the time axis of one's life. The functional neuroanatomy subserving autobiographical memory is known to include prefrontal, medial and lateral temporal, as well as retrosplenial brain areas; however, whether gender differences exist in neural correlates of autobiographical memory remains to be clarified. We reanalyzed data from a previous functional magnetic resonance imaging (fMRI) experiment to investigate gender-related differences in the neural bases of autobiographical memories with differential remoteness and emotional valence. On the behavioral level, there were no significant gender differences in memory performance or emotional intensity of memories. Activations common to males and females during autobiographical memory retrieval were observed in a bilateral network of brain areas comprising medial and lateral temporal regions, including hippocampal and parahippocampal structures, posterior cingulate, as well as prefrontal cortex. In males (relative to females), all types of autobiographical memories investigated were associated with differential activation of the left parahippocampal gyrus. By contrast, right dorsolateral prefrontal cortex was activated differentially by females. In addition, the right insula was activated differentially in females during remote and negative memory retrieval. The data show gender-related differential neural activations within the network subserving autobiographical memory in both genders. We suggest that the differential activations may reflect gender-specific cognitive strategies during access to autobiographical memories that do not necessarily affect the behavioral level of memory performance and emotionality. (c) 2005 Wiley-Liss, Inc.

Remembering to learn: independent place and journey coding mechanisms contribute to memory transfer.

PubMed

Bahar, Amir S; Shapiro, Matthew L

2012-02-08

The neural mechanisms that integrate new episodes with established memories are unknown. When rats explore an environment, CA1 cells fire in place fields that indicate locations. In goal-directed spatial memory tasks, some place fields differentiate behavioral histories ("journey-dependent" place fields) while others do not ("journey-independent" place fields). To investigate how these signals inform learning and memory for new and familiar episodes, we recorded CA1 and CA3 activity in rats trained to perform a "standard" spatial memory task in a plus maze and in two new task variants. A "switch" task exchanged the start and goal locations in the same environment; an "altered environment" task contained unfamiliar local and distal cues. In the switch task, performance was mildly impaired, new firing maps were stable, but the proportion and stability of journey-dependent place fields declined. In the altered environment, overall performance was strongly impaired, new firing maps were unstable, and stable proportions of journey-dependent place fields were maintained. In both tasks, memory errors were accompanied by a decline in journey codes. The different dynamics of place and journey coding suggest that they reflect separate mechanisms and contribute to distinct memory computations. Stable place fields may represent familiar relationships among environmental features that are required for consistent memory performance. Journey-dependent activity may correspond with goal-directed behavioral sequences that reflect expectancies that generalize across environments. The complementary signals could help link current events with established memories, so that familiarity with either a behavioral strategy or an environment can inform goal-directed learning.

REMEMBERING TO LEARN: INDEPENDENT PLACE AND JOURNEY CODING MECHANISMS CONTRIBUTE TO MEMORY TRANSFER

PubMed Central

Bahar, Amir S.; Shapiro, Matthew L.

2012-01-01

The neural mechanisms that integrate new episodes with established memories are unknown. When rats explore an environment, CA1 cells fire in place fields that indicate locations. In goal-directed spatial memory tasks, some place fields differentiate behavioral histories (journey-dependent place fields) while others do not (journey-independent place fields). To investigate how these signals inform learning and memory for new and familiar episodes, we recorded CA1 and CA3 activity in rats trained to perform a standard spatial memory task in a plus maze and in two new task variants. A switch task exchanged the start and goal locations in the same environment; an altered environment task contained unfamiliar local and distal cues. In the switch task, performance was mildly impaired, new firing maps were stable, but the proportion and stability of journey-dependent place fields declined. In the altered environment, overall performance was strongly impaired, new firing maps were unstable, and stable proportions of journey-dependent place fields were maintained. In both tasks, memory errors were accompanied by a decline in journey codes. The different dynamics of place and journey coding suggest that they reflect separate mechanisms and contribute to distinct memory computations. Stable place fields may represent familiar relationships among environmental features that are required for consistent memory performance. Journey-dependent activity may correspond with goal directed behavioral sequences that reflect expectancies that generalize across environments. The complementary signals could help link current events with established memories, so that familiarity with either a behavioral strategy or an environment can inform goal-directed learning. PMID:22323731

Age-related differences in associative memory: the role of sensory decline.

PubMed

Naveh-Benjamin, Moshe; Kilb, Angela

2014-09-01

Numerous studies show age-related decline in episodic memory. One of the explanations for this decline points to older adults' deficit in associative memory, reflecting the difficulties they have in binding features of episodes into cohesive entities and retrieving these bindings. Here, we evaluate the degree to which this deficit may be mediated by sensory loss associated with increased age. In 2 experiments, young adults studied word pairs that were degraded at encoding either visually (Experiment 1) or auditorily (Experiment 2). We then tested their memory for both the component words and the associations with recognition tests. For both experiments, young adults under nondegraded conditions showed an advantage in associative over item memory, relative to a group of older adults. In contrast, under perceptually degraded conditions younger adults performed similarly to the older adults who were tested under nondegraded conditions. More specifically, under perceptual degradation, young adults' associative memory declined and their component memory improved somewhat, resulting in an associative deficit, similar to that shown by older adults. This evidence is consistent with a sensory acuity decline in old age being one mediator in the associative deficit of older adults. These results broaden our understanding of age-related memory changes and how sensory and cognitive processes interact to shape these changes. The theoretical implications of these results are discussed with respect to mechanisms underlying age-related changes in episodic memory and resource tradeoffs in the encoding of component and associative memory. PsycINFO Database Record (c) 2014 APA, all rights reserved.

175.4 The Relationship of Aging and Inflammatory Biomarkers to Gray Matter Volume and Episodic Memory Performance in Schizophrenia: Evidence of Pathological Accelerated Aging

PubMed Central

Gama, Clarissa

2017-01-01

Abstract Background: Schizophrenia (SZ) is associated with increased somatic morbidity and mortality, in addition to cognitive impairments similar to those seen in normal aging, which may suggest that pathological accelerated aging occurs in SZ. Therefore, we aim to evaluate the relationships of age, telomere length (TL) and CCL11 (aging and inflammatory biomarkers), and gray matter volumes (GM) to episodic memory performance in individuals with SZ compared to healthy controls (HC). Methods: 112 participants (48 SZ and 64 HC) underwent clinical and memory assessments, structural MRI, and had their peripheral blood drawn for biomarkers analysis. Comparisons of group means and correlations were performed. Results: Participants with SZ had decreased TL and GM residual volume, increased CCL11, and worse memory performance compared to HC. In SZ, shorter TL was related to increased CCL11, and they were both related to reduced GM residual volume, all of which were related to worse memory performance. Older age was only associated with reduced GM, but longer duration of illness was related with all the aforementioned variables. Younger age of disease onset was related with increased CCL11 levels and worse memory performance. In HC, there were no significant correlations except for between memory and GM. Conclusion: Our results are consistent with accelerated aging in SZ. These results may indicate that it is not age itself, but the impact of the disease associated with a pathological accelerated aging that leads to impaired outcomes in SZ. Akira Sawa, johns Hopkins University, Johns Hopkins Hospital and Medical Institutions

Personal semantics: at the crossroads of semantic and episodic memory.

PubMed

Renoult, Louis; Davidson, Patrick S R; Palombo, Daniela J; Moscovitch, Morris; Levine, Brian

2012-11-01

Declarative memory is usually described as consisting of two systems: semantic and episodic memory. Between these two poles, however, may lie a third entity: personal semantics (PS). PS concerns knowledge of one's past. Although typically assumed to be an aspect of semantic memory, it is essentially absent from existing models of knowledge. Furthermore, like episodic memory (EM), PS is idiosyncratically personal (i.e., not culturally-shared). We show that, depending on how it is operationalized, the neural correlates of PS can look more similar to semantic memory, more similar to EM, or dissimilar to both. We consider three different perspectives to better integrate PS into existing models of declarative memory and suggest experimental strategies for disentangling PS from semantic and episodic memory. Copyright © 2012 Elsevier Ltd. All rights reserved.

Latent change models of adult cognition: are changes in processing speed and working memory associated with changes in episodic memory?

PubMed

Hertzog, Christopher; Dixon, Roger A; Hultsch, David F; MacDonald, Stuart W S

2003-12-01

The authors used 6-year longitudinal data from the Victoria Longitudinal Study (VLS) to investigate individual differences in amount of episodic memory change. Latent change models revealed reliable individual differences in cognitive change. Changes in episodic memory were significantly correlated with changes in other cognitive variables, including speed and working memory. A structural equation model for the latent change scores showed that changes in speed and working memory predicted changes in episodic memory, as expected by processing resource theory. However, these effects were best modeled as being mediated by changes in induction and fact retrieval. Dissociations were detected between cross-sectional ability correlations and longitudinal changes. Shuffling the tasks used to define the Working Memory latent variable altered patterns of change correlations.

A Randomized, Double-Blinded, Placebo-Controlled Study to Compare the Safety and Efficacy of Low Dose Enhanced Wild Blueberry Powder and Wild Blueberry Extract (ThinkBlue™) in Maintenance of Episodic and Working Memory in Older Adults.

PubMed

Whyte, Adrian R; Cheng, Nancy; Fromentin, Emilie; Williams, Claire M

2018-05-23

Previous research has shown beneficial effects of polyphenol-rich diets in ameliorating cognitive decline in aging adults. Here, using a randomized, double blinded, placebo-controlled chronic intervention, we investigated the effect of two proprietary blueberry formulations on cognitive performance in older adults; a whole wild blueberry powder at 500 mg (WBP500) and 1000 mg (WBP1000) and a purified extract at 100 mg (WBE111). One hundred and twenty-two older adults (65⁻80 years) were randomly allocated to a 6-month, daily regimen of either placebo or one of the three interventions. Participants were tested at baseline, 3, and 6 months on a battery of cognitive tasks targeting episodic memory, working memory and executive function, alongside mood and cardiovascular health parameters. Linear mixed model analysis found intervention to be a significant predictor of delayed word recognition on the Reys Auditory Verbal Learning Task (RAVLT), with simple contrast analysis revealing significantly better performance following WBE111 at 3 months. Similarly, performance on the Corsi Block task was predicted by treatment, with simple contrast analysis revealing a trend for better performance at 3 months following WBE111. Treatment also significantly predicted systolic blood pressure (SBP) with simple contrast analysis revealing lower SBP following intervention with WBE111 in comparison to placebo. These results indicate 3 months intervention with WBE111 can facilitate better episodic memory performance in an elderly population and reduce cardiovascular risk factors over 6 months.

Episodic Recollection in Animals: ''If It Walks like a Duck and Quacks like a Duck...''

ERIC Educational Resources Information Center

Eichenbaum, H.; Fortin, N.J.; Ergorul, C.; Wright, S.P.; Agster, K.L.

2005-01-01

In humans, episodic memory is most commonly defined as the subjective experience of recollection, presenting a major challenge to the identification of episodic memory in animals. Here we take the position that episodic memory also has several other distinctive qualities that can be assessed objectively in animals, as well as humans, and the…

Imaging episodic memory: implications for cognitive theories and phenomena.

PubMed

Nyberg, L

1999-01-01

Functional neuroimaging studies are beginning to identify neuroanatomical correlates of various cognitive functions. This paper presents results relevant to several theories and phenomena of episodic memory, including component processes of episodic retrieval, encoding specificity, inhibition, item versus source memory, encoding-retrieval overlap, and the picture-superiority effect. Overall, by revealing specific activation patterns, the results provide support for existing theoretical views and they add some unique information which may be important to consider in future attempts to develop cognitive theories of episodic memory.

Bridging the Gap between Brain and Behavior: Cognitive and Neural Mechanisms of Episodic Memory

PubMed Central

Eichenbaum, Howard; Fortin, Norbert J

2005-01-01

The notion that non-human animals are capable of episodic memory is highly controversial. Here, we review recent behavioral work from our laboratory showing that the fundamental features of episodic memory can be observed in rats and that, as in humans, this capacity relies on the hippocampus. We also discuss electrophysiological evidence, from our laboratory and that of others, pointing to associative and sequential coding in hippocampal cells as potential neural mechanisms underlying episodic memory. PMID:16596982

Multimodal Feature Integration in the Angular Gyrus during Episodic and Semantic Retrieval

PubMed Central

Bonnici, Heidi M.; Richter, Franziska R.; Yazar, Yasemin

2016-01-01

Much evidence from distinct lines of investigation indicates the involvement of angular gyrus (AnG) in the retrieval of both episodic and semantic information, but the region's precise function and whether that function differs across episodic and semantic retrieval have yet to be determined. We used univariate and multivariate fMRI analysis methods to examine the role of AnG in multimodal feature integration during episodic and semantic retrieval. Human participants completed episodic and semantic memory tasks involving unimodal (auditory or visual) and multimodal (audio-visual) stimuli. Univariate analyses revealed the recruitment of functionally distinct AnG subregions during the retrieval of episodic and semantic information. Consistent with a role in multimodal feature integration during episodic retrieval, significantly greater AnG activity was observed during retrieval of integrated multimodal episodic memories compared with unimodal episodic memories. Multivariate classification analyses revealed that individual multimodal episodic memories could be differentiated in AnG, with classification accuracy tracking the vividness of participants' reported recollections, whereas distinct unimodal memories were represented in sensory association areas only. In contrast to episodic retrieval, AnG was engaged to a statistically equivalent degree during retrieval of unimodal and multimodal semantic memories, suggesting a distinct role for AnG during semantic retrieval. Modality-specific sensory association areas exhibited corresponding activity during both episodic and semantic retrieval, which mirrored the functional specialization of these regions during perception. The results offer new insights into the integrative processes subserved by AnG and its contribution to our subjective experience of remembering. SIGNIFICANCE STATEMENT Using univariate and multivariate fMRI analyses, we provide evidence that functionally distinct subregions of angular gyrus (AnG) contribute to the retrieval of episodic and semantic memories. Our multivariate pattern classifier could distinguish episodic memory representations in AnG according to whether they were multimodal (audio-visual) or unimodal (auditory or visual) in nature, whereas statistically equivalent AnG activity was observed during retrieval of unimodal and multimodal semantic memories. Classification accuracy during episodic retrieval scaled with the trial-by-trial vividness with which participants experienced their recollections. Therefore, the findings offer new insights into the integrative processes subserved by AnG and how its function may contribute to our subjective experience of remembering. PMID:27194327

Multimodal Feature Integration in the Angular Gyrus during Episodic and Semantic Retrieval.

PubMed

Bonnici, Heidi M; Richter, Franziska R; Yazar, Yasemin; Simons, Jon S

2016-05-18

Much evidence from distinct lines of investigation indicates the involvement of angular gyrus (AnG) in the retrieval of both episodic and semantic information, but the region's precise function and whether that function differs across episodic and semantic retrieval have yet to be determined. We used univariate and multivariate fMRI analysis methods to examine the role of AnG in multimodal feature integration during episodic and semantic retrieval. Human participants completed episodic and semantic memory tasks involving unimodal (auditory or visual) and multimodal (audio-visual) stimuli. Univariate analyses revealed the recruitment of functionally distinct AnG subregions during the retrieval of episodic and semantic information. Consistent with a role in multimodal feature integration during episodic retrieval, significantly greater AnG activity was observed during retrieval of integrated multimodal episodic memories compared with unimodal episodic memories. Multivariate classification analyses revealed that individual multimodal episodic memories could be differentiated in AnG, with classification accuracy tracking the vividness of participants' reported recollections, whereas distinct unimodal memories were represented in sensory association areas only. In contrast to episodic retrieval, AnG was engaged to a statistically equivalent degree during retrieval of unimodal and multimodal semantic memories, suggesting a distinct role for AnG during semantic retrieval. Modality-specific sensory association areas exhibited corresponding activity during both episodic and semantic retrieval, which mirrored the functional specialization of these regions during perception. The results offer new insights into the integrative processes subserved by AnG and its contribution to our subjective experience of remembering. Using univariate and multivariate fMRI analyses, we provide evidence that functionally distinct subregions of angular gyrus (AnG) contribute to the retrieval of episodic and semantic memories. Our multivariate pattern classifier could distinguish episodic memory representations in AnG according to whether they were multimodal (audio-visual) or unimodal (auditory or visual) in nature, whereas statistically equivalent AnG activity was observed during retrieval of unimodal and multimodal semantic memories. Classification accuracy during episodic retrieval scaled with the trial-by-trial vividness with which participants experienced their recollections. Therefore, the findings offer new insights into the integrative processes subserved by AnG and how its function may contribute to our subjective experience of remembering. Copyright © 2016 Bonnici, Richter, et al.

Role of PFC during retrieval of recognition memory in rodents.

PubMed

Bekinschtein, Pedro; Weisstaub, Noelia

2014-01-01

One of the challenges for memory researches is the study of the neurobiology of episodic memory which is defined by the integration of all the different components of experiences that support the conscious recollection of events. The features of episodic memory includes a particular object or person ("what"), the context in which the experience took place ("where") and the particular time at which the event occurred ("when"). Although episodic memory has been mainly studied in humans, there are many studies that demonstrate these features in non-human animals. Here, we summarize a set of studies that employ different versions of recognition memory tasks in animals to study the role of the medial prefrontal cortex in episodic memory. Copyright © 2014 Elsevier Ltd. All rights reserved.

Contextual match and cue-independence of retrieval-induced forgetting: Testing the prediction of the model by Norman, Newman, and Detre (2007).

PubMed

Hanczakowski, Maciej; Mazzoni, Giuliana

2013-05-01

Retrieval-induced forgetting (RIF) is the finding of impaired memory performance for information stored in long-term memory due to retrieval of a related set of information. This phenomenon is often assigned to operations of a specialized mechanism recruited to resolve interference during retrieval by deactivating competing memory representations. This inhibitory account is supported by, among others, findings showing that RIF occurs with independent cues not used during retrieval practice. However, these findings are not always consistent. Recently, Norman, Newman, and Detre (2007) have proposed a model that aims at resolving discrepancies concerning cue-independence of RIF. The model predicts that RIF should be present with independent cues when episodic associations are created between independent cues and their targets in the same episodic context that is later used to cue memory during retrieval practice. In the present study we aimed to test this prediction. We associated studied items with semantically unrelated words during the main study phase of the retrieval practice paradigm, and we tested memory with both cues used during retrieval practice (Experiment 2) and episodic associates serving as independent cues (Experiments 3a and 3b). Although RIF was present when the same cues were used during retrieval practice and a final test, contrary to the prediction formulated by Norman et al., RIF failed to emerge when episodic associates were employed as independent cues.

Serum 25-hydroxyvitamin D is associated with reduced verbal episodic memory in healthy, middle-aged and older adults.

PubMed

Lam, Virginie; Albrecht, Matthew A; Takechi, Ryusuke; Prasopsang, Prachya; Lee, Ya Ping; Foster, Jonathan K; Mamo, John C L

2016-06-01

There is increasing evidence supporting an association of higher serum vitamin D concentration with better cognitive performance in older individuals. However, to date, consideration of the putative association between vitamin D and cognition has been based principally on studies investigating clinical participant samples manifesting vitamin D deficiency, particularly in older people. Moreover, relationships between vitamin D and cognition are typically not considered in the context of counter-regulatory calcium-modulating hormones or calcium homeostasis. Serum vitamin D/bioactive (ionised) calcium/parathyroid hormone homeostasis was considered in the context of cognitive performance in healthy, middle-aged and older individuals. A cross-sectional sample of 179 participants between the ages of 47-84 years was recruited for this study (114 females, 65 males). Participants provided fasting blood samples for analysis of serum 25-hydroxyvitamin D levels, ionised calcium (iCa) and parathyroid hormone (PTH) and completed cognitive measures of verbal episodic learning and memory. Serum 25-hydroxyvitamin D concentrations were negatively associated (with and without covariates of age, gender, depression and NART scores, iCa, and PTH) with measures of verbal episodic learning and memory, in particular with trial 5 of the Rey Auditory Verbal Learning Test (RAVLT) and long-delay free recall on the RAVLT. Overall, the findings from this study suggest an association between higher vitamin D status and poorer performance on verbal episodic memory in middle-aged and older individuals with normal vitamin D-calcium-PTH homeostasis. Despite requiring replication in other participant samples, this is a potentially important finding as it indicates that it may not be beneficial from a cognitive perspective to provide vitamin D supplements in individuals with already adequate vitamin D status.

Cannabis use and cognitive function in first episode psychosis: differential effect of heavy use.

PubMed

Núñez, Christian; Ochoa, Susana; Huerta-Ramos, Elena; Baños, Iris; Barajas, Ana; Dolz, Montserrat; Sánchez, Bernardo; Del Cacho, Núria; Usall, Judith

2016-03-01

First episode patients and patients with schizophrenia exhibit increased rates of cannabis use compared to the general population. Contrary to what has been reported in studies with healthy people, most of the published studies so far have reported no impairments or even beneficial effects on neurocognition associated with cannabis consumption in psychotic patients. However, these studies did not address the effects of very high cannabis consumption. Our aim in this study was to assess the effects on neurocognition of medium and heavy cannabis consumption in first psychotic episode patients. A total of 74 patients were included in the study and assigned to three different groups according to their mean cannabis consumption during the last year (non-users, medium users, and heavy users). Participants were administered verbal memory and other neurocognitive tasks. Heavy cannabis users were significantly impaired in all the verbal memory measures with respect to non-users, including immediate (p = .026), short-term (p = .005), and long-term (p = .002) memory. There were no significant differences between medium and non-users. Moreover, non-users performed better than all cannabis users in the arithmetic task (p = .020). Heavy cannabis consumption was associated with more commission errors in the continuous performance task (CPT) (p = .008) and more time to complete trail making test A (TMT-A) (p = .008), compared to the group of medium users. Heavy cannabis consumption seems to impair verbal memory in first psychotic episode patients. Heavy users also perform worse than medium users in other neurocognitive tasks. Based on the results and the available evidence, a dose-related effect of cannabis consumption is suggested.

The Interaction between Semantic Representation and Episodic Memory.

PubMed

Fang, Jing; Rüther, Naima; Bellebaum, Christian; Wiskott, Laurenz; Cheng, Sen

2018-02-01

The experimental evidence on the interrelation between episodic memory and semantic memory is inconclusive. Are they independent systems, different aspects of a single system, or separate but strongly interacting systems? Here, we propose a computational role for the interaction between the semantic and episodic systems that might help resolve this debate. We hypothesize that episodic memories are represented as sequences of activation patterns. These patterns are the output of a semantic representational network that compresses the high-dimensional sensory input. We show quantitatively that the accuracy of episodic memory crucially depends on the quality of the semantic representation. We compare two types of semantic representations: appropriate representations, which means that the representation is used to store input sequences that are of the same type as those that it was trained on, and inappropriate representations, which means that stored inputs differ from the training data. Retrieval accuracy is higher for appropriate representations because the encoded sequences are less divergent than those encoded with inappropriate representations. Consistent with our model prediction, we found that human subjects remember some aspects of episodes significantly more accurately if they had previously been familiarized with the objects occurring in the episode, as compared to episodes involving unfamiliar objects. We thus conclude that the interaction with the semantic system plays an important role for episodic memory.

Is "Learning" episodic memory? Distinct cognitive and neuroanatomic correlates of immediate recall during learning trials in neurologically normal aging and neurodegenerative cohorts.

PubMed

Casaletto, K B; Marx, G; Dutt, S; Neuhaus, J; Saloner, R; Kritikos, L; Miller, B; Kramer, J H

2017-07-28

Although commonly interpreted as a marker of episodic memory during neuropsychological exams, relatively little is known regarding the neurobehavior of "total learning" immediate recall scores. Medial temporal lobes are clearly associated with delayed recall performances, yet immediate recall may necessitate networks beyond traditional episodic memory. We aimed to operationalize cognitive and neuroanatomic correlates of total immediate recall in several aging syndromes. Demographically-matched neurologically normal adults (n=91), individuals with Alzheimer's disease (n=566), logopenic variant primary progressive aphasia (PPA) (n=34), behavioral variant frontotemporal dementia (n=97), semantic variant PPA (n=71), or nonfluent/agrammatic variant PPA (n=39) completed a neurocognitive battery, including the CVLT-Short Form trials 1-4 Total Immediate Recall; a majority subset also completed a brain MRI. Regressions covaried for age and sex, and MMSE in cognitive and total intracranial volume in neuroanatomic models. Neurologically normal adults demonstrated a heterogeneous pattern of cognitive associations with total immediate recall (executive, speed, delayed recall), such that no singular cognitive or neuroanatomic correlate uniquely predicted performance. Within the clinical cohorts, there were syndrome-specific cognitive and neural associations with total immediate recall; e.g., semantic processing was the strongest cognitive correlate in svPPA (partial r=0.41), while frontal volumes was the only meaningful neural correlate in bvFTD (partial r=0.20). Medial temporal lobes were not independently associated with total immediate recall in any group (ps>0.05). Multiple neurobehavioral systems are associated with "total learning" immediate recall scores that importantly differ across distinct clinical syndromes. Conventional memory networks may not be sufficient or even importantly contribute to total immediate recall in many syndromes. Interpreting learning scores as equivalent to episodic memory may be erroneous. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evidence of episodic-like memory in cuttlefish.

PubMed

Jozet-Alves, Christelle; Bertin, Marion; Clayton, Nicola S

2013-12-02

The recollection of past experiences allows us to recall what happened during a particular event, and where and when it occurred [1]. Since the first study on episodic-like memory in scrub-jays [2], there has been widespread acceptance of the idea that tests in animals should integrate the 'what', 'where' and 'when' components of a unique event that occurred in the past [3,4]. This is referred to as episodic-like memory rather than episodic memory per se, in acknowledgement of the lack of evidence for, or against, the phenomenological aspects that accompany episodic recollection in humans. So far, evidence for episodic-like memory has only been found in some birds and mammals. We show here that cuttlefish, cephalopod mollusks, keep track of what they have eaten, and where and how long ago they ate, in order to match their foraging behavior with the time of replenishing of different foods. Foraging in cuttlefish fulfils the criteria of 'what', 'where' and 'when' of unique events and thus provides behavioral evidence of episodic-like memory in an invertebrate. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Construction of Semantic Memory: Grammar-Based Representations Learned from Relational Episodic Information

PubMed Central

Battaglia, Francesco P.; Pennartz, Cyriel M. A.

2011-01-01

After acquisition, memories underlie a process of consolidation, making them more resistant to interference and brain injury. Memory consolidation involves systems-level interactions, most importantly between the hippocampus and associated structures, which takes part in the initial encoding of memory, and the neocortex, which supports long-term storage. This dichotomy parallels the contrast between episodic memory (tied to the hippocampal formation), collecting an autobiographical stream of experiences, and semantic memory, a repertoire of facts and statistical regularities about the world, involving the neocortex at large. Experimental evidence points to a gradual transformation of memories, following encoding, from an episodic to a semantic character. This may require an exchange of information between different memory modules during inactive periods. We propose a theory for such interactions and for the formation of semantic memory, in which episodic memory is encoded as relational data. Semantic memory is modeled as a modified stochastic grammar, which learns to parse episodic configurations expressed as an association matrix. The grammar produces tree-like representations of episodes, describing the relationships between its main constituents at multiple levels of categorization, based on its current knowledge of world regularities. These regularities are learned by the grammar from episodic memory information, through an expectation-maximization procedure, analogous to the inside–outside algorithm for stochastic context-free grammars. We propose that a Monte-Carlo sampling version of this algorithm can be mapped on the dynamics of “sleep replay” of previously acquired information in the hippocampus and neocortex. We propose that the model can reproduce several properties of semantic memory such as decontextualization, top-down processing, and creation of schemata. PMID:21887143

Effects of emotion and reward motivation on neural correlates of episodic memory encoding: a PET study.

PubMed

Shigemune, Yayoi; Abe, Nobuhito; Suzuki, Maki; Ueno, Aya; Mori, Etsuro; Tashiro, Manabu; Itoh, Masatoshi; Fujii, Toshikatsu

2010-05-01

It is known that emotion and reward motivation promote long-term memory formation. It remains unclear, however, how and where emotion and reward are integrated during episodic memory encoding. In the present study, subjects were engaged in intentional encoding of photographs under four different conditions that were made by combining two factors (emotional valence, negative or neutral; and monetary reward value, high or low for subsequent successful recognition) during H2 15O positron emission tomography (PET) scanning. As for recognition performance, we found significant main effects of emotional valence (negative>neutral) and reward value (high value>low value), without an interaction between the two factors. Imaging data showed that the left amygdala was activated during the encoding conditions of negative pictures relative to neutral pictures, and the left orbitofrontal cortex was activated during the encoding conditions of high reward pictures relative to low reward pictures. In addition, conjunction analysis of these two main effects detected right hippocampal activation. Although we could not find correlations between recognition performance and activity of these three regions, we speculate that the right hippocampus may integrate the effects of emotion (processed in the amygdala) and monetary reward (processed in the orbitofrontal cortex) on episodic memory encoding. 2010 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

The nature and time-course of medial temporal lobe contributions to semantic retrieval: an fMRI study on verbal fluency.

PubMed

Sheldon, Signy; Moscovitch, Morris

2012-06-01

Recent investigations have shown that the medial temporal lobe (MTL), a region thought to be exclusive to episodic memory, can also influence performance on tests of semantic memory. The present study examined further the nature of MTL contributions to semantic memory tasks by tracking MTL activation as participants performed category fluency, a traditional test of semantic retrieval. For categories that were inherently autobiographical (e.g. names of friends), the MTLs were activated throughout the time period in which items were generated, consistent with the MTLs role in retrieving autobiographical memories. For categories that could not benefit from autobiographical or spatial/context information (e.g. governmental offices), the MTL was not implicated at any time point. For categories for which both prototypical and episodically-related information exists (e.g. kitchen utensils), there was more robust MTL activity for the open-ended, late generation periods compared with the more well-defined, early item generation time periods. We interpret these results as suggesting that early in the generation phase, responses are based on well-rehearsed prototypical knowledge whereas later performance relies more on open-ended strategies, such as deriving exemplars from personally relevant contextual information (e.g. imagining one's own kitchen). These findings and interpretation were consistent with the results of an initial, separate behavioral study (Expt 1), that used the distinctiveness of responses as a measure of open-endedness across the generation phase: Response distinctiveness corresponded to the predicted open-endedness of the various tasks at early and late phases. Overall, this is consistent with the view that as generation of semantic information becomes open-ended, it recruits processes from other domains, such as episodic memory, to support performance. Copyright © 2011 Wiley Periodicals, Inc.

Remembering a visit to the psychology lab: Implications of Mild Cognitive Impairment.

PubMed

Davidson, Patrick S R; Cooper, Lara; Taler, Vanessa

2016-09-01

Morris Moscovitch has emphasized the importance of sensitively and carefully measuring cognition in the real world. With this lesson in mind, we examined the real-world episodic memory problems of older adults with Mild Cognitive Impairment (MCI). MCI patients often complain of episodic memory problems and perform poorly on standardized neuropsychological measures, but we still do not know enough about their actual difficulties remembering real experiences. A few days after their visit to the laboratory for an experimental session, we telephoned 19 MCI patients and 34 healthy participants without warning to ask what they could recollect about 16 elements of their visit. The patients had difficulty remembering the details of their visit, and reported lower ratings of memory vividness compared to healthy participants. Patients' memory for the visit was commensurate with their performance on three standard clinical memory assessment measures (delayed 5 word recall from the Montreal Cognitive Assessment, long delay free recall from the California Verbal Learning Test-II and recall of the details of the Wechsler Memory Scale-III Logical Memory stories), providing evidence for the generalizability of the clinical measures. Putting these findings together with those from Moscovitch and colleagues (Murphy et al., 2008) can help us better understand the real-world memory implications of Mild Cognitive Impairment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Decreased prefrontal functional brain response during memory testing in women with Cushing's syndrome in remission.

PubMed

Ragnarsson, Oskar; Stomby, Andreas; Dahlqvist, Per; Evang, Johan A; Ryberg, Mats; Olsson, Tommy; Bollerslev, Jens; Nyberg, Lars; Johannsson, Gudmundur

2017-08-01

Neurocognitive dysfunction is an important feature of Cushing's syndrome (CS). Our hypothesis was that patients with CS in remission have decreased functional brain responses in the prefrontal cortex and hippocampus during memory testing. In this cross-sectional study we included 19 women previously treated for CS and 19 controls matched for age, gender, and education. The median remission time was 7 (IQR 6-10) years. Brain activity was studied with functional magnetic resonance imaging during episodic- and working-memory tasks. The primary regions of interest were the prefrontal cortex and the hippocampus. A voxel-wise comparison of functional brain responses in patients and controls was performed. During episodic-memory encoding, patients displayed lower functional brain responses in the left and right prefrontal gyrus (p<0.001) and in the right inferior occipital gyrus (p<0.001) compared with controls. There was a trend towards lower functional brain responses in the left posterior hippocampus in patients (p=0.05). During episodic-memory retrieval, the patients displayed lower functional brain responses in several brain areas with the most predominant difference in the right prefrontal cortex (p<0.001). During the working memory task, patients had lower response in the prefrontal cortices bilaterally (p<0.005). Patients, but not controls, had lower functional brain response during a more complex working memory task compared with a simpler one. In conclusion, women with CS in long-term remission have reduced functional brain responses during episodic and working memory testing. This observation extends previous findings showing long-term adverse effects of severe hypercortisolaemia on brain function. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neurofeedback training of EEG alpha rhythm enhances episodic and working memory.

PubMed

Hsueh, Jen-Jui; Chen, Tzu-Shan; Chen, Jia-Jin; Shaw, Fu-Zen

2016-07-01

Neurofeedback training (NFT) of the alpha rhythm has been used for several decades but is still controversial in regards to its trainability and effects on working memory. Alpha rhythm of the frontoparietal region are associated with either the intelligence or memory of healthy subjects and are also related to pathological states. In this study, alpha NFT effects on memory performances were explored. Fifty healthy participants were recruited and randomly assigned into a group receiving a 8-12-Hz amplitude (Alpha) or a group receiving a random 4-Hz amplitude from the range of 7 to 20 Hz (Ctrl). Three NFT sessions per week were conducted for 4 weeks. Working memory was assessed by both a backward digit span task and an operation span task, and episodic memory was assessed using a word pair task. Four questionnaires were used to assess anxiety, depression, insomnia, and cognitive function. The Ctrl group had no change in alpha amplitude and duration. In contrast, the Alpha group showed a progressive significant increase in the alpha amplitude and total alpha duration of the frontoparietal region. Accuracies of both working and episodic memories were significantly improved in a large proportion of participants of the Alpha group, particularly for those with remarkable alpha-amplitude increases. Scores of four questionnaires fell in a normal range before and after NFT. The current study provided supporting evidence for alpha trainability within a small session number compared with that of therapy. The findings suggested the enhancement of working and episodic memory through alpha NFT. Hum Brain Mapp 37:2662-2675, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Rapid formation and flexible expression of memories of subliminal word pairs.

PubMed

Reber, Thomas P; Henke, Katharina

2011-01-01

Our daily experiences are incidentally and rapidly encoded as episodic memories. Episodic memories consist of numerous associations (e.g., who gave what to whom where and when) that can be expressed flexibly in new situations. Key features of episodic memory are speed of encoding, its associative nature, and its representational flexibility. Another defining feature of human episodic memory has been consciousness of encoding/retrieval. Here, we show that humans can rapidly form associations between subliminal words and minutes later retrieve these associations even if retrieval words were conceptually related to, but different from encoding words. Because encoding words were presented subliminally, associative encoding, and retrieval were unconscious. Unconscious association formation and retrieval were dependent on a preceding understanding of task principles. We conclude that key computations underlying episodic memory - rapid encoding and flexible expression of associations - can operate outside consciousness.

Cerebral amyloidosis associated with cognitive decline in autosomal dominant Alzheimer disease

PubMed Central

Wang, Fen; Gordon, Brian A.; Ryman, Davis C.; Ma, Shengmei; Xiong, Chengjie; Hassenstab, Jason; Goate, Alison; Fagan, Anne M.; Cairns, Nigel J.; Marcus, Daniel S.; McDade, Eric; Ringman, John M.; Graff-Radford, Neill R.; Ghetti, Bernardino; Farlow, Martin R.; Sperling, Reisa; Salloway, Steve; Schofield, Peter R.; Masters, Colin L.; Martins, Ralph N.; Rossor, Martin N.; Jucker, Mathias; Danek, Adrian; Förster, Stefan; Lane, Christopher A.S.; Morris, John C.; Bateman, Randall J.

2015-01-01

Objective: To investigate the associations of cerebral amyloidosis with concurrent cognitive performance and with longitudinal cognitive decline in asymptomatic and symptomatic stages of autosomal dominant Alzheimer disease (ADAD). Methods: Two hundred sixty-three participants enrolled in the Dominantly Inherited Alzheimer Network observational study underwent neuropsychological evaluation as well as PET scans with Pittsburgh compound B. One hundred twenty-one participants completed at least 1 follow-up neuropsychological evaluation. Four composite cognitive measures representing global cognition, episodic memory, language, and working memory were generated using z scores from a battery of 13 standard neuropsychological tests. General linear mixed-effects models were used to investigate the relationship between baseline cerebral amyloidosis and baseline cognitive performance and whether baseline cerebral amyloidosis predicts cognitive change over time (mean follow-up 2.32 years ± 0.92, range 0.89–4.19) after controlling for estimated years from expected symptom onset, APOE ε4 allelic status, and education. Results: In asymptomatic mutation carriers, amyloid burden was not associated with baseline cognitive functioning but was significantly predictive of longitudinal decline in episodic memory. In symptomatic mutation carriers, cerebral amyloidosis was correlated with worse baseline performance in multiple cognitive composites and predicted greater decline over time in global cognition, working memory, and Mini-Mental State Examination. Conclusions: Cerebral amyloidosis predicts longitudinal episodic memory decline in presymptomatic ADAD and multidomain cognitive decline in symptomatic ADAD. These findings imply that amyloidosis in the brain is an indicator of early cognitive decline and provides a useful outcome measure for early assessment and prevention treatment trials. PMID:26245925

Cognitive and affective theory of mind abilities in alcohol-dependent patients: the role of autobiographical memory.

PubMed

Nandrino, Jean-Louis; Gandolphe, Marie-Charlotte; Alexandre, Charlotte; Kmiecik, Elodie; Yguel, Jacques; Urso, Laurent

2014-10-01

Many studies of patients with alcohol dependence (AD) have highlighted their difficulty in identifying both their own emotional state and those of a social partner. We examined (1) the cognitive and affective theory of mind (ToM) abilities of AD patients and (2) how the efficiency of their autobiographical memory (AM) can affect the effectiveness of ToM ability. In a cross-sectional design, AD patients (N=50) and healthy controls (N=30) completed a ToM movie paradigm (Versailles-Situational Intention Reading, V-SIR) in which they inferred the intentions of characters in movies depicting social interactions, and the "Reading the Mind in the Eyes" Test (RMET), which assessed the emotional dimension of the ToM. AM was investigated using the "Autobiographical Memory Interview" (AMI) to assess both episodic and semantic components of AM. Concerning ToM, patients with AD showed lower performance in the RMET than control participants, whereas no difference was observed on the V-SIR test. AD patients had lower scores than controls on the AMI, for both episodic and semantic components and for different periods of life. A multiple linear regression analysis also showed that AM deficits might predict lower ToM performance, especially for the RMET task. Patients with AD have a specific affective ToM deficit. They used episodic memories to perceive the emotions of others, whereas controls used preferentially semantic memories to perform the task. Both these deficits could constitute a risk of relapse and should be a target for psychotherapeutic interventions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Cerebral amyloidosis associated with cognitive decline in autosomal dominant Alzheimer disease.

PubMed

Wang, Fen; Gordon, Brian A; Ryman, Davis C; Ma, Shengmei; Xiong, Chengjie; Hassenstab, Jason; Goate, Alison; Fagan, Anne M; Cairns, Nigel J; Marcus, Daniel S; McDade, Eric; Ringman, John M; Graff-Radford, Neill R; Ghetti, Bernardino; Farlow, Martin R; Sperling, Reisa; Salloway, Steve; Schofield, Peter R; Masters, Colin L; Martins, Ralph N; Rossor, Martin N; Jucker, Mathias; Danek, Adrian; Förster, Stefan; Lane, Christopher A S; Morris, John C; Benzinger, Tammie L S; Bateman, Randall J

2015-09-01

To investigate the associations of cerebral amyloidosis with concurrent cognitive performance and with longitudinal cognitive decline in asymptomatic and symptomatic stages of autosomal dominant Alzheimer disease (ADAD). Two hundred sixty-three participants enrolled in the Dominantly Inherited Alzheimer Network observational study underwent neuropsychological evaluation as well as PET scans with Pittsburgh compound B. One hundred twenty-one participants completed at least 1 follow-up neuropsychological evaluation. Four composite cognitive measures representing global cognition, episodic memory, language, and working memory were generated using z scores from a battery of 13 standard neuropsychological tests. General linear mixed-effects models were used to investigate the relationship between baseline cerebral amyloidosis and baseline cognitive performance and whether baseline cerebral amyloidosis predicts cognitive change over time (mean follow-up 2.32 years ± 0.92, range 0.89-4.19) after controlling for estimated years from expected symptom onset, APOE ε4 allelic status, and education. In asymptomatic mutation carriers, amyloid burden was not associated with baseline cognitive functioning but was significantly predictive of longitudinal decline in episodic memory. In symptomatic mutation carriers, cerebral amyloidosis was correlated with worse baseline performance in multiple cognitive composites and predicted greater decline over time in global cognition, working memory, and Mini-Mental State Examination. Cerebral amyloidosis predicts longitudinal episodic memory decline in presymptomatic ADAD and multidomain cognitive decline in symptomatic ADAD. These findings imply that amyloidosis in the brain is an indicator of early cognitive decline and provides a useful outcome measure for early assessment and prevention treatment trials. © 2015 American Academy of Neurology.

Study on memories of temporal lobes and the principles of lateralization using near infrared spectroscopy

NASA Astrophysics Data System (ADS)

Kamakura, Katsutoshi

2007-01-01

In this study we measured the variation of brain blood quantity (Oxy-Hb, Deoxy-Hb and Total-Hb) in the temporal lobes using near infrared spectroscopy (NIRS) when the tasks of the memories were presented to the subjects. The memories are classified into the short-term memory (STM) and the long-term memory (LTM) including the episodic and semantic memories. The subjects joined in this study are 11 persons who are university students including graduate students. We used the language task of letter-number sequencing, also reverse sequencing to measure STM and the task of the episodic memory to measure LTM. As a result of analysis, concerning the episodic memory, the variation of Oxy-Hb in the left temporal lobe was larger than that of Oxy-Hb in the right temporal lobe. The result might suggest that the episodic memory has a relationship with cerebral dominance concerning language area in the left temporal lobe. It seems that the episodic memory meditated with the function of language used in this study is much stored in the left temporal lobe than in the right temporal lobe. This result coincides with the principles of lateralization. The variation of Oxy-Hb in the language task of letter-number sequencing was smaller than that of Oxy-Hb in the language task of the episodic memory.

Genetic architecture of learning and delayed recall: a twin study of episodic memory.

PubMed

Panizzon, Matthew S; Lyons, Michael J; Jacobson, Kristen C; Franz, Carol E; Grant, Michael D; Eisen, Seth A; Xian, Hong; Kremen, William S

2011-07-01

Although episodic memory is often conceptualized as consisting of multiple component processes, there is a lack of understanding as to whether these processes are influenced by the same or different genetic determinants. The aim of the present study was to utilize multivariate twin analyses to elucidate the degree to which learning and delayed recall, two critical measures of episodic memory performance, have common or different genetic and environmental influences. Participants from the Vietnam Era Twin Study of Aging (314 monozygotic twin pairs, 259 dizygotic twin pairs, and 47 unpaired twins) were assessed using the second edition of the California Verbal Learning Test. Mean age at the time of the evaluation was 55.4 years (SD = 2.5). Model fitting revealed the presence of a higher-order latent factor influencing learning, short- and long-delay free recall, with a heritability of .36. The best-fitting model also indicated specific genetic influences on learning, which accounted for 10% of the overall variance. Given that learning involves the acquisition and retrieval of information, whereas delayed recall involves only retrieval, we conclude that these specific effects are likely to reflect genes that are specific to acquisition processes. These results demonstrate that even in nonclinical populations, it is possible to differentiate component processes in episodic memory. These different genetic influences may have implications for gene association studies, as well as other genetic studies of cognitive aging and disorders of episodic memory such as Alzheimer's disease or mild cognitive impairment. PsycINFO Database Record (c) 2011 APA, all rights reserved.

Auditory cortical function during verbal episodic memory encoding in Alzheimer's disease.

PubMed

Dhanjal, Novraj S; Warren, Jane E; Patel, Maneesh C; Wise, Richard J S

2013-02-01

Episodic memory encoding of a verbal message depends upon initial registration, which requires sustained auditory attention followed by deep semantic processing of the message. Motivated by previous data demonstrating modulation of auditory cortical activity during sustained attention to auditory stimuli, we investigated the response of the human auditory cortex during encoding of sentences to episodic memory. Subsequently, we investigated this response in patients with mild cognitive impairment (MCI) and probable Alzheimer's disease (pAD). Using functional magnetic resonance imaging, 31 healthy participants were studied. The response in 18 MCI and 18 pAD patients was then determined, and compared to 18 matched healthy controls. Subjects heard factual sentences, and subsequent retrieval performance indicated successful registration and episodic encoding. The healthy subjects demonstrated that suppression of auditory cortical responses was related to greater success in encoding heard sentences; and that this was also associated with greater activity in the semantic system. In contrast, there was reduced auditory cortical suppression in patients with MCI, and absence of suppression in pAD. Administration of a central cholinesterase inhibitor (ChI) partially restored the suppression in patients with pAD, and this was associated with an improvement in verbal memory. Verbal episodic memory impairment in AD is associated with altered auditory cortical function, reversible with a ChI. Although these results may indicate the direct influence of pathology in auditory cortex, they are also likely to indicate a partially reversible impairment of feedback from neocortical systems responsible for sustained attention and semantic processing. Copyright © 2012 American Neurological Association.

Distinct slow and fast cortical theta dynamics in episodic memory retrieval.

PubMed

Pastötter, Bernhard; Bäuml, Karl-Heinz T

2014-07-01

Brain oscillations in the theta frequency band (3-8 Hz) have been shown to be critically involved in human episodic memory retrieval. In prior work, both positive and negative relationships between cortical theta power and retrieval success have been reported. This study examined the hypothesis that slow and fast cortical theta oscillations at the edges of the traditional theta frequency band are differentially related to retrieval success. Scalp EEG was recorded in healthy human participants as they performed a cued-recall episodic memory task. Slow (~3 Hz) and fast (~7 Hz) theta oscillations at retrieval were examined as a function of whether an item was recalled or not and as a function of the items' output position at test. Recall success typically declines with output position, due to increases in interference level. The results showed that slow theta power was positively related but fast theta power was negatively related to retrieval success. Concurrent positive and negative episodic memory effects for slow and fast theta oscillations were dissociable in time and space, showing different time courses and different spatial locations on the scalp. Moreover, fast theta power increased from early to late output positions, whereas slow theta power was unaffected by items' output position. Together with prior work, the results suggest that slow and fast theta oscillations have distinct functional roles in episodic memory retrieval, with slow theta oscillations being related to processes of recollection and conscious awareness, and fast theta oscillations being linked to processes of interference and interference resolution. Copyright © 2014 Elsevier Inc. All rights reserved.

A Calendar Savant with Episodic Memory Impairments

PubMed Central

Olson, Ingrid R.; Berryhill, Marian E.; Drowos, David B.; Brown, Lawrence; Chatterjee, Anjan

2010-01-01

Patients with memory disorders have severely restricted learning and memory. For instance, patients with anterograde amnesia can learn motor procedures as well as retaining some restricted ability to learn new words and factual information. However, such learning is inflexible and frequently inaccessible to conscious awareness. Here we present a case of patient AC596, a 25-year old male with severe episodic memory impairments, presumably due to anoxia during a preterm birth. In contrast to his poor episodic memory, he exhibits savant-like memory for calendar information that can be flexibly accessed by day, month, and year cues. He also has the ability to recollect the exact date of a wide range of personal experiences over the past 20 years. The patient appears to supplement his generally poor episodic memory by using memorized calendar information as a retrieval cue for autobiographical events. These findings indicate that islands of preserved memory functioning, such as a highly developed semantic memory system, can exist in individuals with severely impaired episodic memory systems. In this particular case, our patient’s memory for dates far outstripped that of normal individuals and served as a keen retrieval cue, allowing him to access information that was otherwise unavailable. PMID:20104390

Episodic Memory and Beyond: The Hippocampus and Neocortex in Transformation

PubMed Central

Moscovitch, Morris; Cabeza, Roberto; Winocur, Gordon; Nadel, Lynn

2016-01-01

The last decade has seen dramatic technological and conceptual changes in research on episodic memory and the brain. New technologies, and increased use of more naturalistic observations, have enabled investigators to delve deeply into the structures that mediate episodic memory, particularly the hippocampus, and to track functional and structural interactions among brain regions that support it. Conceptually, episodic memory is increasingly being viewed as subject to lifelong transformations that are reflected in the neural substrates that mediate it. In keeping with this dynamic perspective, research on episodic memory (and the hippocampus) has infiltrated domains, from perception to language and from empathy to problem solving, that were once considered outside its boundaries. Using the component process model as a framework, and focusing on the hippocampus, its subfields, and specialization along its longitudinal axis, along with its interaction with other brain regions, we consider these new developments and their implications for the organization of episodic memory and its contribution to functions in other domains. PMID:26726963

Episodic Memory and Beyond: The Hippocampus and Neocortex in Transformation.

PubMed

Moscovitch, Morris; Cabeza, Roberto; Winocur, Gordon; Nadel, Lynn

2016-01-01

The last decade has seen dramatic technological and conceptual changes in research on episodic memory and the brain. New technologies, and increased use of more naturalistic observations, have enabled investigators to delve deeply into the structures that mediate episodic memory, particularly the hippocampus, and to track functional and structural interactions among brain regions that support it. Conceptually, episodic memory is increasingly being viewed as subject to lifelong transformations that are reflected in the neural substrates that mediate it. In keeping with this dynamic perspective, research on episodic memory (and the hippocampus) has infiltrated domains, from perception to language and from empathy to problem solving, that were once considered outside its boundaries. Using the component process model as a framework, and focusing on the hippocampus, its subfields, and specialization along its longitudinal axis, along with its interaction with other brain regions, we consider these new developments and their implications for the organization of episodic memory and its contribution to functions in other domains.

Neutral and emotional episodic memory: global impairment after lorazepam or scopolamine.

PubMed

Kamboj, Sunjeev K; Curran, H Valerie

2006-11-01

Benzodiazepines and anticholinergic drugs have repeatedly been shown to impair episodic memory for emotionally neutral material in humans. However, their effect on memory for emotionally laden stimuli has been relatively neglected. We sought to investigate the effects of the benzodiazepine, lorazepam, and the anticholinergic, scopolamine, on incidental episodic memory for neutral and emotional components of a narrative memory task in humans. A double-blind, placebo-controlled independent group design was used with 48 healthy volunteers to examine the effects of these drugs on emotional and neutral episodic memory. As expected, the emotional memory advantage was retained for recall and recognition memory under placebo conditions. However, lorazepam and scopolamine produced anterograde recognition memory impairments on both the neutral and emotional components of the narrative, although floor effects were obtained for recall memory. Furthermore, compared with placebo, recognition memory for both central (gist) and peripheral (detail) aspects of neutral and emotional elements of the narrative was poorer after either drug. Benzodiazepine-induced GABAergic enhancement or scopolamine-induced cholinergic hypofunction results in a loss of the enhancing effect of emotional arousal on memory. Furthermore, lorazepam- and scopolamine-induced memory impairment for both gist (which is amygdala dependent) and detail raises the possibility that their effects on emotional memory do not depend only on the amygdala. We discuss the results with reference to potential clinical/forensic implications of processing emotional memories under conditions of globally impaired episodic memory.

Elements of episodic-like memory in animals.

PubMed

Clayton, N S; Griffiths, D P; Emery, N J; Dickinson, A

2001-09-29

A number of psychologists have suggested that episodic memory is a uniquely human phenomenon and, until recently, there was little evidence that animals could recall a unique past experience and respond appropriately. Experiments on food-caching memory in scrub jays question this assumption. On the basis of a single caching episode, scrub jays can remember when and where they cached a variety of foods that differ in the rate at which they degrade, in a way that is inexplicable by relative familiarity. They can update their memory of the contents of a cache depending on whether or not they have emptied the cache site, and can also remember where another bird has hidden caches, suggesting that they encode rich representations of the caching event. They make temporal generalizations about when perishable items should degrade and also remember the relative time since caching when the same food is cached in distinct sites at different times. These results show that jays form integrated memories for the location, content and time of caching. This memory capability fulfils Tulving's behavioural criteria for episodic memory and is thus termed 'episodic-like'. We suggest that several features of episodic memory may not be unique to humans.

The medial prefrontal cortex-lateral entorhinal cortex circuit is essential for episodic-like memory and associative object-recognition.

PubMed

Chao, Owen Y; Huston, Joseph P; Li, Jay-Shake; Wang, An-Li; de Souza Silva, Maria A

2016-05-01

The prefrontal cortex directly projects to the lateral entorhinal cortex (LEC), an important substrate for engaging item-associated information and relaying the information to the hippocampus. Here we ask to what extent the communication between the prefrontal cortex and LEC is critically involved in the processing of episodic-like memory. We applied a disconnection procedure to test whether the interaction between the medial prefrontal cortex (mPFC) and LEC is essential for the expression of recognition memory. It was found that male rats that received unilateral NMDA lesions of the mPFC and LEC in the same hemisphere, exhibited intact episodic-like (what-where-when) and object-recognition memories. When these lesions were placed in the opposite hemispheres (disconnection), episodic-like and associative memories for object identity, location and context were impaired. However, the disconnection did not impair the components of episodic memory, namely memory for novel object (what), object place (where) and temporal order (when), per se. Thus, the present findings suggest that the mPFC and LEC are a critical part of a neural circuit that underlies episodic-like and associative object-recognition memory. © 2015 Wiley Periodicals, Inc.

Developmental amnesia: Fractionation of developing memory systems.

PubMed

Temple, Christine M; Richardson, Paul

2006-07-01

Study of the developmental amnesias utilizing a cognitive neuropsychological methodology has highlighted the dissociations that may occur between the development of components of memory. M.M., a new case of developmental amnesia, was identified after screening from the normal population on cognitive and memory measures. Retrospective investigation found that he was of low birthweight. M.M. had impaired semantic memory for knowledge of facts and words. There was impaired episodic memory for words and stories but intact episodic memory for visual designs and features. This forms a double dissociation with Dr S. (Temple, 1992), who had intact verbal but impaired visual episodic memory. M.M. also had impaired autobiographical episodic memory. Nevertheless, learning over repeated trials occurred, consistent with previous theorizing that learning is not simply the effect of recurrent episodic memory. Nor is it the same as establishing semantic memory, since for M.M. semantic memory is also impaired. Within reading, there was an impaired lexico-semantic system, elevated levels of homophone confusion, but intact phonological reading, consistent with surface dyslexia and raising issues about the interrelationship of the semantic system and literacy development. The results are compatible with discrete semi-independent components within memory development, whereby deficits are associated with residual normality, but there may also be an explicit relationship between the semantic memory system and both vocabulary and reading acquisition.

Residual memory dysfunction in recurrent major depressive disorder--a longitudinal study from Juntendo University Mood Disorder Project.

PubMed

Maeshima, Hitoshi; Baba, Hajime; Nakano, Yoshiyuki; Satomura, Emi; Namekawa, Yuki; Takebayashi, Naoko; Suzuki, Toshihito; Mimura, Masaru; Arai, Heii

2012-12-20

Depression may increase the risk of developing Alzheimer's disease. Large cohort studies have shown that recurrent depression is associated with a risk of developing dementia. Other studies have documented smaller hippocampal volume in patients with recurrent depression. It is speculative that a greater risk of developing dementia may result from a higher number of previous depressive episodes. This study compared patients with recurrent and single-episode depression in the remitted stage, and healthy controls to elucidate the impact of the number of depressive episodes on memory. Logical memory and visual reproduction subtests of the Wechsler Memory Scale-Revised were given to 68 patients with major depressive disorder (MDD) (30 patients with a single episode and residual 38 patients with recurrent multiple episodes) and 57 healthy controls. The patients with MDD received memory assessment at the time of initial remission and at the follow-up period 3 years after remission. At the time of initial remission, scores of both logical memory and visual reproduction subtests were significantly lower in both patient groups compared with healthy controls. At follow-up, memory dysfunction of the single-episode group disappeared, whereas scores in the recurrent group remained significantly lower than those of the single-episode group and controls. All patients in the present study were on antidepressant medications. Patients with recurrent MDD with multiple depressive episodes showed residual memory dysfunction even after 3 years of remission. Persistence of memory deficits in the recurrent depression may be a risk factor for developing dementia. Copyright © 2012 Elsevier B.V. All rights reserved.

Why do we remember? The communicative function of episodic memory.

PubMed

Mahr, Johannes; Csibra, Gergely

2017-01-19

Episodic memory has been analyzed in a number of different ways in both philosophy and psychology, and most controversy has centered on its self-referential, 'autonoetic' character. Here, we offer a comprehensive characterization of episodic memory in representational terms, and propose a novel functional account on this basis. We argue that episodic memory should be understood as a distinctive epistemic attitude taken towards an event simulation. On this view, episodic memory has a metarepresentational format and should not be equated with beliefs about the past. Instead, empirical findings suggest that the contents of human episodic memory are often constructed in the service of the explicit justification of such beliefs. Existing accounts of episodic memory function that have focused on explaining its constructive character through its role in 'future-oriented mental time travel' neither do justice to its capacity to ground veridical beliefs about the past nor to its representational format. We provide an account of the metarepresentational structure of episodic memory in terms of its role in communicative interaction. The generative nature of recollection allows us to represent and communicate the reasons for why we hold certain beliefs about the past. In this process, autonoesis corresponds to the capacity to determine when and how to assert epistemic authority in making claims about the past. A domain where such claims are indispensable are human social engagements. Such engagements commonly require the justification of entitlements and obligations, which is often possible only by explicit reference to specific past events.

Retrieval of high-fidelity memory arises from distributed cortical networks.

PubMed

Wais, Peter E; Jahanikia, Sahar; Steiner, Daniel; Stark, Craig E L; Gazzaley, Adam

2017-04-01

Medial temporal lobe (MTL) function is well established as necessary for memory of facts and events. It is likely that lateral cortical regions critically guide cognitive control processes to tune in high-fidelity details that are most relevant for memory retrieval. Here, convergent results from functional and structural MRI show that retrieval of detailed episodic memory arises from lateral cortical-MTL networks, including regions of inferior frontal and angular gyrii. Results also suggest that recognition of items based on low-fidelity, generalized information, rather than memory arising from retrieval of relevant episodic details, is not associated with functional connectivity between MTL and lateral cortical regions. Additionally, individual differences in microstructural properties in white matter pathways, associated with distributed MTL-cortical networks, are positively correlated with better performance on a mnemonic discrimination task. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Neurocognitive deficits or stress overload: Why do individuals with schizophrenia show poor performance in neurocognitive tests?

PubMed

Krkovic, Katarina; Moritz, Steffen; Lincoln, Tania M

2017-05-01

Poor performance in neurocognitive tasks is consistently found across studies in all stages of schizophrenia spectrum disorders and is interpreted as an underlying, brain function-related, neurocognitive deficit. However, neurocognitive test performance in schizophrenia might be compromised by patients' increased stress level. We investigated group-differences in neurocognitive performance while accounting for psychophysiological (salivary cortisol, heart rate, skin conductance level) and self-reported stress. We included 35 patients with schizophrenia, 29 participants with attenuated psychotic symptoms, 26 first-degree relatives of individuals with schizophrenia and 28 healthy controls. Participants completed a neurocognitive test battery that assessed processing speed, task switching, attention, working memory, verbal episodic memory, and verbal comprehension. Multivariate analyses of covariance (MANCOVA) were calculated to test for main effects of group on neurocognitive performance thereby not accounting versus accounting for confounding effects of stress. As expected, patients with schizophrenia scored lower than the other groups in all neurocognitive domains. Participants with attenuated psychotic symptoms, first-degree relatives and healthy individuals did not differ from each other in their performance. After accounting for heart rate and self-reported stress, the multivariate effect of group on neurocognition remained significant, but was rendered non-significant for specific domains - working memory capacity, episodic memory, and long-term memory. The findings imply that stress is relevant to neurocognitive performance and this should be taken into account when interpreting the origin of performance deficits in schizophrenia patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Retention and Fading of Military Skills: Literature Review

DTIC Science & Technology

2000-04-01

distinction between availability and accessibility of human memory ( Tulving & Pearlstone , 1966; Tulving , 1983). Observation of some decrement in performance...Army War College. TULVING , E. (1983). Elements of Episodic Memory. London: Oxford University Press. TULVING , E., & PEARLSTONE , Z. (1966). Availability...store ( Tulving , 1983). To access this knowledge, the individual consciously recalls facts about the task and attempts to use them to guide performance

Left Posterior Parietal Cortex Participates in Both Task Preparation and Episodic Retrieval

PubMed Central

Phillips, Jeffrey S.; Velanova, Katerina; Wolk, David A.; Wheeler, Mark E.

2012-01-01

Optimal memory retrieval depends not only on the fidelity of stored information, but also on the attentional state of the subject. Factors such as mental preparedness to engage in stimulus processing can facilitate or hinder memory retrieval. The current study used functional magnetic resonance imaging (fMRI) to distinguish preparatory brain activity before episodic and semantic retrieval tasks from activity associated with retrieval itself. A catch-trial imaging paradigm permitted separation of neural responses to preparatory task cues and memory probes. Episodic and semantic task preparation engaged a common set of brain regions, including the bilateral intraparietal sulcus (IPS), left fusiform gyrus (FG), and the pre-supplementary motor area (pre-SMA). In the subsequent retrieval phase, the left IPS was among a set of frontoparietal regions that responded differently to old and new stimuli. In contrast, the right IPS responded to preparatory cues with little modulation during memory retrieval. The findings support a strong left-lateralization of retrieval success effects in left parietal cortex, and further indicate that left IPS performs operations that are common to both task preparation and memory retrieval. Such operations may be related to attentional control, monitoring of stimulus relevance, or retrieval. PMID:19285142

Pushing typists back on the learning curve: Memory chunking improves retrieval of prior typing episodes.

PubMed

Yamaguchi, Motonori; Randle, James M; Wilson, Thomas L; Logan, Gordon D

2017-09-01

Hierarchical control of skilled performance depends on chunking of several lower-level units into a single higher-level unit. The present study examined the relationship between chunking and recognition of trained materials in the context of typewriting. In 3 experiments, participants were trained with typing nonwords and were later tested on their recognition of the trained materials. In Experiment 1, participants typed the same words or nonwords in 5 consecutive trials while performing a concurrent memory task. In Experiment 2, participants typed the materials with lags between repetitions without a concurrent memory task. In both experiments, recognition of typing materials was associated with better chunking of the materials. Experiment 3 used the remember-know procedure to test the recollection and familiarity components of recognition. Remember judgments were associated with better chunking than know judgments or nonrecognition. These results indicate that chunking is associated with explicit recollection of prior typing episodes. The relevance of the existing memory models to chunking in typewriting was considered, and it is proposed that memory chunking improves retrieval of trained typing materials by integrating contextual cues into the memory traces. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Mental time travel and the shaping of the human mind

PubMed Central

Suddendorf, Thomas; Addis, Donna Rose; Corballis, Michael C.

2009-01-01

Episodic memory, enabling conscious recollection of past episodes, can be distinguished from semantic memory, which stores enduring facts about the world. Episodic memory shares a core neural network with the simulation of future episodes, enabling mental time travel into both the past and the future. The notion that there might be something distinctly human about mental time travel has provoked ingenious attempts to demonstrate episodic memory or future simulation in non-human animals, but we argue that they have not yet established a capacity comparable to the human faculty. The evolution of the capacity to simulate possible future events, based on episodic memory, enhanced fitness by enabling action in preparation of different possible scenarios that increased present or future survival and reproduction chances. Human language may have evolved in the first instance for the sharing of past and planned future events, and, indeed, fictional ones, further enhancing fitness in social settings. PMID:19528013

Cognitive functions in first-episode depression and recurrent depressive disorder.

PubMed

Talarowska, Monika; Zajączkowska, Marlena; Gałecki, Piotr

2015-03-01

Cognitive deficits in the course of depressive disorders affect mainly memory, attention and the frontal functions. They are associated with both an earlier onset of symptoms and prolonged episodes. The main aim of the study was to verify the hypothesis of differences in the effectiveness of cognitive processes between patients with a first episode of depression (ED-I) and recurrent depressive disorders (rDD). The study comprised 210 subjects: patients with ED-I (n=60) and patients with rDD (n=150). The assessment of cognitive functions was based on performance of the Trail Making Test, the Stroop Test, the Verbal Fluency Test, the California Verbal Learning Test (CVLT) and the digit span from WAIS-R. There were no statistically significant differences between the analysed groups in the severity of depressive symptoms. The negative impact of depressive symptoms on the effectiveness of cognitive functions was observed. The ED-I group recorded better results compared to the rDD group in terms of the speed of information processing, visual-spatial and auditory-verbal memory and executive functions, auditory-verbal immediate and delayed memory, ability to learn and verbal fluency. The same differences were observed with respect to the patients from the ED-I group and the patients with the second episode of depression (ED-II) in the course of rDD. There are significant differences in cognitive functioning of patients with a depressive episode and recurrent depressive disorders. These differences are already visible from the second episode of a major depressive disorder. Memory, verbal fluency and frontal functions are reduced.

[Early episodic memory impairments in Alzheimer's disease].

PubMed

Ergis, A-M; Eusop-Roussel, E

2008-05-01

Patients with Alzheimer's disease (AD) show early episodic memory impairments. Such deficits reflect specific impairments affecting one or several stages of encoding, storage and retrieval processes. However, AD patients not only have great difficulty retrieving memories and information but also suffer from distortions of memory, as intrusions and false recognitions. Intrusions can be defined as the unintentional recall of inappropriate information in a laboratory-learning tasks such as word-list recall and story recall. False recognition refers to the erroneous recognition of information that was not previously presented. The first objective of this review is to present studies from the literature that allowed a better understanding of the nature of episodic memory deficits in AD, and to examine recent research on false memories. The second part of this review is aimed at presenting recent research conducted on prospective memory (PM) in Alzheimer's disease. Prospective memory situations involve forming intentions and then realizing those intentions at some appropriate time in the future. Everyday examples of prospective memory include remembering to buy bread on the way home from work, remembering to give friends a message upon next encountering them, and remembering to take medication. Patients suffering from AD show difficulties in performing prospective tasks in daily life, according to the complaints of their care givers, and these difficulties are massively present at the first stages of the disease. Nevertheless, very few studies have been dedicated to this subject, although the evaluation of PM could be helpful for the early diagnosis of AD.

The Neural Representations Underlying Human Episodic Memory.

PubMed

Xue, Gui

2018-06-01

A fundamental question of human episodic memory concerns the cognitive and neural representations and processes that give rise to the neural signals of memory. By integrating behavioral tests, formal computational models, and neural measures of brain activity patterns, recent studies suggest that memory signals not only depend on the neural processes and representations during encoding and retrieval, but also on the interaction between encoding and retrieval (e.g., transfer-appropriate processing), as well as on the interaction between the tested events and all other events in the episodic memory space (e.g., global matching). In addition, memory signals are also influenced by the compatibility of the event with the existing long-term knowledge (e.g., schema matching). These studies highlight the interactive nature of human episodic memory. Copyright © 2018 Elsevier Ltd. All rights reserved.

Did the popsicle melt? Preschoolers' performance in an episodic-like memory task.

PubMed

Martin-Ordas, Gema; Atance, Cristina M; Caza, Julian

2017-10-01

Episodic memory has been tested in non-human animals using depletion paradigms that assess recollection for the "what", "where" and "when" (i.e., how long ago). This paradigm has not been used with human children, yet doing so would provide another means to explore their episodic memory development. Using a depletion paradigm, preschool-aged children were presented in two trials with a preferred food that was only edible after a short interval and a less-preferred food that was edible after the short and long intervals. Younger (mean = 40 months) and older (mean = 65 months) children tended to choose their preferred food after the short intervals, but did not switch to selecting their less-preferred food after the long intervals. Importantly, their choices did not differ with age. Although older children better remembered "what", "where", and "what is where" than did younger children, neither age group successfully estimated "how long ago" an event occurred. Finally, both age groups spontaneously recalled information about Trial 1. We also analysed the relation between the different measures used in the study but no clear patterns emerged. Results are discussed with respect to the cognitive mechanisms necessary to succeed in depletion paradigms and the measurement of episodic memory more broadly.

Nonlinear correlations impair quantification of episodic memory by mesial temporal BOLD activity.

PubMed

Klamer, Silke; Zeltner, Lena; Erb, Michael; Klose, Uwe; Wagner, Kathrin; Frings, Lars; Groen, Georg; Veil, Cornelia; Rona, Sabine; Lerche, Holger; Milian, Monika

2013-07-01

Episodic memory processes can be investigated using different functional MRI (fMRI) paradigms. The purpose of the present study was to examine correlations between neuropsychological memory test scores and BOLD signal changes during fMRI scanning using three different memory tasks. Twenty-eight right-handed healthy subjects underwent three paradigms, (a) a word pair, (b) a space-labyrinth, and (c) a face-name association paradigm. These paradigms were compared for their value in memory quantification and lateralization by calculating correlations between the BOLD signals in the mesial temporal lobe and behavioral data derived from a neuropsychological test battery. As expected, group analysis showed left-sided activation for the verbal, a tendency to right-sided activation for the spatial, and bilateral activation for the face-name paradigm. No linear correlations were observed between neuropsychological data and activation in the temporo-mesial region. However, we found significant u-shaped correlations between behavioral memory performance and activation in both the verbal and the face-name paradigms, that is, BOLD signal changes were greater not only among participants who performed best on the neuropsychological tests, but also among the poorest performers. The figural learning task did not correlate with the activations in the space-labyrinth paradigm at all. We interpreted the u-shaped correlations to be due to compensatory hippocampal activations associated with low performance when people try unsuccessfully to remember presented items. Because activation levels did not linearly increase with memory performance, the latter cannot be quantified by fMRI alone, but only be used in conjunction with neuropsychological testing. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Dopamine modulates episodic memory persistence in old age

PubMed Central

Chowdhury, Rumana; Guitart-Masip, Marc; Bunzeck, Nico; Dolan, Raymond J; Düzel, Emrah

2013-01-01

Activation of the hippocampus is required in order to encode memories for new events (or episodes). Observations from animal studies suggest that for these memories to persist beyond 4 to 6 hours, a release of dopamine generated by strong hippocampal activation is needed. This predicts that dopaminergic enhancement should improve human episodic memory persistence also for events encoded with weak hippocampal activation. Here, using pharmacological fMRI in an elderly population where there is a loss of dopamine neurons as part of normal aging, we show this very effect. The dopamine precursor levodopa led to a dose-dependent (inverted U-shape) persistent episodic memory benefit for images of scenes when tested after 6 hours, independent of whether encoding-related hippocampal fMRI activity was weak or strong (U-shaped dose-response relationship). This lasting improvement even for weakly encoded events supports a role for dopamine in human episodic memory consolidation albeit operating within a narrow dose range. PMID:23055489