Self-imagination can enhance memory in individuals with schizophrenia.

PubMed

Raffard, Stéphane; Bortolon, Catherine; Burca, Mariana; Novara, Caroline; Gely-Nargeot, Marie-Christine; Capdevielle, Delphine; Van der Linden, Martial

2016-01-01

Previous research has demonstrated that self-referential strategies can be applied to improve memory in various memory- impaired populations. However, little is known regarding the relative effectiveness of self-referential strategies in schizophrenia patients. The main aim of this study was to assess the effectiveness of a new self-referential strategy known as self- imagination (SI) on a free recall task. Twenty schizophrenia patients and 20 healthy controls intentionally encoded words under five instructions: superficial processing, semantic processing, semantic self-referential processing, episodic self-referential processing and semantic self- imagining. Other measures included depression, psychotic symptoms and cognitive measures. We found a SI effect in memory as self- imagining resulted in better performance in memory retrieval than semantic and superficial encoding in schizophrenia patients. The memory boost for self-referenced information in comparison to semantic processing was not found for other self-referential strategies. In addition no relationship between clinical variables and free recall performances was found. In controls, the SI condition did not result in better performance. The three self-referential strategies yielded better free recall than both superficial and semantic encoding. This study provides evidence of the clinical utility of self-imagining as a mnemonic strategy in schizophrenia patients.

Verbal learning and memory impairments in posttraumatic stress disorder: the role of encoding strategies.

PubMed

Johnsen, Grethe E; Asbjørnsen, Arve E

2009-01-30

The present study examined mechanisms underlying verbal memory impairments in patients with posttraumatic stress disorder (PTSD). Earlier studies have reported that the verbal learning and memory alterations in PTSD are related to impaired encoding, but the use of encoding and organizational strategies in patients with PTSD has not been fully explored. This study examined organizational strategies in 21 refugees/immigrants exposed to war and political violence who fulfilled DSM-IV criteria for chronic PTSD compared with a control sample of 21 refugees/immigrants with similar exposure, but without PTSD. The California Verbal Learning Test was administered to examine differences in organizational strategies and memory. The semantic clustering score was slightly reduced in both groups, but the serial cluster score was significantly impaired in the PTSD group and they also reported more items from the recency region of the list. In addition, intrusive errors were significantly increased in the PTSD group. The data support an assumption of changed memory strategies in patients with PTSD associated with a specific impairment in executive control. However, memory impairment and the use of ineffective learning strategies may not be related to PTSD symptomatology only, but also to self-reported symptoms of depression and general distress.

Can't control yourself? Monitor those bad habits.

PubMed

Quinn, Jeffrey M; Pascoe, Anthony; Wood, Wendy; Neal, David T

2010-04-01

What strategies can people use to control unwanted habits? Past work has focused on controlling other kinds of automatic impulses, especially temptations. The nature of habit cuing calls for certain self-control strategies. Because the slow-to-change memory trace of habits is not amenable to change or reinterpretation, successful habit control involves inhibiting the unwanted response when activated in memory. In support, two episode-sampling diary studies demonstrated that bad habits, unlike responses to temptations, were controlled most effectively through spontaneous use of vigilant monitoring (thinking "don't do it," watching carefully for slipups). No other strategy was useful in controlling strong habits, despite that stimulus control was effective at inhibiting responses to temptations. A subsequent experiment showed that vigilant monitoring aids habit control, not by changing the strength of the habit memory trace but by heightening inhibitory, cognitive control processes. The implications of these findings for behavior change interventions are discussed.

When is working memory important for arithmetic? The impact of strategy and age.

PubMed

Cragg, Lucy; Richardson, Sophie; Hubber, Paula J; Keeble, Sarah; Gilmore, Camilla

2017-01-01

Our ability to perform arithmetic relies heavily on working memory, the manipulation and maintenance of information in mind. Previous research has found that in adults, procedural strategies, particularly counting, rely on working memory to a greater extent than retrieval strategies. During childhood there are changes in the types of strategies employed, as well as an increase in the accuracy and efficiency of strategy execution. As such it seems likely that the role of working memory in arithmetic may also change, however children and adults have never been directly compared. This study used traditional dual-task methodology, with the addition of a control load condition, to investigate the extent to which working memory requirements for different arithmetic strategies change with age between 9-11 years, 12-14 years and young adulthood. We showed that both children and adults employ working memory when solving arithmetic problems, no matter what strategy they choose. This study highlights the importance of considering working memory in understanding the difficulties that some children and adults have with mathematics, as well as the need to include working memory in theoretical models of mathematical cognition.

Improving prospective memory in persons with Parkinson disease: A randomized controlled trial

PubMed Central

Foster, Erin R.; McDaniel, Mark A.; Rendell, Peter G.

2017-01-01

Background Prospective memory is essential for productive and independent living and necessary for compliance with prescribed health behaviors. Parkinson disease (PD) can cause prospective memory deficits that are associated with activity limitations and reduced quality of life. Forming implementation intentions is an encoding strategy that may improve prospective memory in this population. Objective To determine the effect of implementation intentions on prospective memory performance in PD. Methods This was a laboratory-based randomized controlled trial. Participants with mild to moderate PD without dementia (N = 62) performed a computerized prospective memory test (Virtual Week) under standard instructions. One week later they were randomly allocated to perform it again while using either implementation intentions or a rehearsal encoding strategy. Results Prospective memory performance was better with the use of both strategies relative to standard instructions. This effect was larger for tasks with event-based compared to time-based cues. In addition, implementation intentions resulted in a larger effect than rehearsal for the non-repeated tasks. Conclusions Strategies that support full encoding of prospective memory cues and actions can improve prospective memory performance among people with PD, particularly for tasks with cues that are readily available in the environment. Implementation intentions may be more effective than rehearsal for non-repeated tasks, but this finding warrants verification. Future work should address transfer of strategy use from the laboratory to everyday life. Targeted strategies to manage prospective memory impairment could improve function and quality of life and significantly impact clinical care for people with PD. (NCT01469741) PMID:28176547

Aging effects in sequential modulations of poorer-strategy effects during execution of memory strategies.

PubMed

Hinault, Thomas; Lemaire, Patrick; Touron, Dayna

2017-02-01

In this study, we asked young adults and older adults to encode pairs of words. For each item, they were told which strategy to use, interactive imagery or rote repetition. Data revealed poorer-strategy effects in both young adults and older adults: Participants obtained better performance when executing better strategies (i.e., interactive-imagery strategy to encode pairs of concrete words; rote-repetition strategy on pairs of abstract words) than with poorer strategies (i.e., interactive-imagery strategy on pairs of abstract words; rote-repetition strategy on pairs of concrete words). Crucially, we showed that sequential modulations of poorer-strategy effects (i.e., poorer-strategy effects being larger when previous items were encoded with better relative to poorer strategies), previously demonstrated in arithmetic, generalise to memory strategies. We also found reduced sequential modulations of poorer-strategy effects in older adults relative to young adults. Finally, sequential modulations of poorer-strategy effects correlated with measures of cognitive control processes, suggesting that these processes underlie efficient trial-to-trial modulations during strategy execution. Differences in correlations with cognitive control processes were also found between older adults and young adults. These findings have important implications regarding mechanisms underlying memory strategy execution and age differences in memory performance.

The influence of strategic encoding on false memory in patients with mild cognitive impairment and Alzheimer's disease dementia.

PubMed

Tat, Michelle J; Soonsawat, Anothai; Nagle, Corinne B; Deason, Rebecca G; O'Connor, Maureen K; Budson, Andrew E

2016-11-01

Patients with Alzheimer's disease (AD) dementia exhibit high rates of memory distortions in addition to their impairments in episodic memory. Several investigations have demonstrated that when healthy individuals (young and old) engaged in an encoding strategy that emphasized the uniqueness of study items (an item-specific encoding strategy), they were able to improve their discrimination between old items and unstudied critical lure items in a false memory task. In the present study we examined if patients with AD could also improve their memory discrimination when engaging in an item-specific encoding strategy. Healthy older adult controls, patients with mild cognitive impairment (MCI) due to AD, and patients with mild AD dementia were asked to study lists of categorized words. In the Item-Specific condition, participants were asked to provide a unique detail or personal experience with each study item. In the Relational condition, they were asked to determine how each item in the list was related to the others. To assess the influence of both strategies, recall and recognition memory tests were administered. Overall, both patient groups exhibited poorer memory in both recall and recognition tests compared to controls. In terms of recognition, healthy older controls and patients with MCI due to AD exhibited improved memory discrimination in the Item-Specific condition compared to the Relational condition, whereas patients with AD dementia did not. We speculate that patients with MCI due to AD use intact frontal networks to effectively engage in this strategy. Published by Elsevier Inc.

The influence of strategic encoding on false memory in patients with mild cognitive impairment and Alzheimer’s disease dementia

PubMed Central

Tat, Michelle J.; Soonsawat, Anothai; Nagle, Corinne B.; Deason, Rebecca G.; O’Connor, Maureen K.; Budson, Andrew E.

2018-01-01

Patients with Alzheimer’s disease (AD) dementia exhibit high rates of memory distortions in addition to their impairments in episodic memory. Several investigations have demonstrated that when healthy individuals (young and old) engaged in an encoding strategy that emphasized the uniqueness of study items (an item-specific encoding strategy), they were able to improve their discrimination between old items and unstudied critical lure items in a false memory task. In the present study we examined if patients with AD could also improve their memory discrimination when engaging in an item-specific encoding strategy. Healthy older adult controls, patients with mild cognitive impairment (MCI) due to AD, and patients with mild AD dementia were asked to study lists of categorized words. In the Item-Specific condition, participants were asked to provide a unique detail or personal experience with each study item. In the Relational condition, they were asked to determine how each item in the list was related to the others. To assess the influence of both strategies, recall and recognition memory tests were administered. Overall, both patient groups exhibited poorer memory in both recall and recognition tests compared to controls. In terms of recognition, healthy older controls and patients with MCI due to AD exhibited improved memory discrimination in the Item-Specific condition compared to the Relational condition, whereas patients with AD dementia did not. We speculate that patients with MCI due to AD use intact frontal networks to effectively engage in this strategy. PMID:27643951

Individual Differences in Working Memory Capacity Predicts Responsiveness to Memory Rehabilitation After Traumatic Brain Injury.

PubMed

Sandry, Joshua; Chiou, Kathy S; DeLuca, John; Chiaravalloti, Nancy D

2016-06-01

To explore how individual differences affect rehabilitation outcomes by specifically investigating whether working memory capacity (WMC) can be used as a cognitive marker to identify who will and will not improve from memory rehabilitation. Post hoc analysis of a randomized controlled clinical trial designed to treat learning and memory impairment after traumatic brain injury (TBI): 2 × 2 between-subjects quasiexperimental design (2 [group: treatment vs control] × 2 [WMC: high vs low]). Nonprofit medical rehabilitation research center. Participants (N=65) with moderate to severe TBI with pre- and posttreatment data. The treatment group completed 10 cognitive rehabilitation sessions in which subjects were taught a memory strategy focusing on learning to use context and imagery to remember information. The placebo control group engaged in active therapy sessions that did not involve learning the memory strategy. Long-term memory percent retention change scores for an unorganized list of words from the California Verbal Learning Test-II. Group and WMC interacted (P=.008, ηp(2)=.12). High WMC participants showed a benefit from treatment compared with low WMC participants. Individual differences in WMC accounted for 45% of the variance in whether participants with TBI in the treatment group benefited from applying the compensatory treatment strategy to learn unorganized information. Individuals with higher WMC showed a significantly greater rehabilitation benefit when applying the compensatory strategy to learn unorganized information. WMC is a useful cognitive marker for identifying participants with TBI who respond to memory rehabilitation with the modified Story Memory Technique. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Functional-anatomic correlates of individual differences in memory.

PubMed

Kirchhoff, Brenda A; Buckner, Randy L

2006-07-20

Memory abilities differ greatly across individuals. To explore a source of these differences, we characterized the varied strategies people adopt during unconstrained encoding. Participants intentionally encoded object pairs during functional MRI. Principal components analysis applied to a strategy questionnaire revealed that participants variably used four main strategies to aid learning. Individuals' use of verbal elaboration and visual inspection strategies independently correlated with their memory performance. Verbal elaboration correlated with activity in a network of regions that included prefrontal regions associated with controlled verbal processing, while visual inspection correlated with activity in a network of regions that included an extrastriate region associated with object processing. Activity in regions associated with use of these strategies was also correlated with memory performance. This study reveals functional-anatomic correlates of verbal and perceptual strategies that are variably used by individuals during encoding. These strategies engage distinct brain regions and may separately influence memory performance.

Distinct discrimination learning strategies and their relation with spatial memory and attentional control in 4- to 14-year-olds.

PubMed

Schmittmann, Verena D; van der Maas, Han L J; Raijmakers, Maartje E J

2012-04-01

Behavioral, psychophysiological, and neuropsychological studies have revealed large developmental differences in various learning paradigms where learning from positive and negative feedback is essential. The differences are possibly due to the use of distinct strategies that may be related to spatial working memory and attentional control. In this study, strategies in performing a discrimination learning task were distinguished in a cross-sectional sample of 302 children from 4 to 14 years of age. The trial-by-trial accuracy data were analyzed with mathematical learning models. The best-fitting model revealed three learning strategies: hypothesis testing, slow abrupt learning, and nonlearning. The proportion of hypothesis-testing children increased with age. Nonlearners were present only in the youngest age group. Feature preferences for the irrelevant dimension had a detrimental effect on performance in the youngest age group. The executive functions spatial working memory and attentional control significantly predicted posterior learning strategy probabilities after controlling for age. Copyright © 2011 Elsevier Inc. All rights reserved.

Central coherence, organizational strategy, and visuospatial memory in children and adolescents with anorexia nervosa.

PubMed

Rose, Mark; Frampton, Ian J; Lask, Bryan

2014-01-01

The vast majority of studies in anorexia nervosa that have investigated the domains of central coherence, organizational strategy, and visuospatial memory have focused on adult samples. In addition, studies investigating visuospatial memory have focused on free recall. No study to date has reported the association between recognition memory and central coherence or organizational strategy in younger people with this disorder, yet the capacity to recognize previously seen visual stimuli may contribute to overall visuospatial ability. Therefore, we investigate these domains in children and adolescents with anorexia nervosa compared to age- and gender-matched healthy controls. There were no significant group differences in immediate, delayed, or recognition memory, central coherence, or organization strategy. When compared with controls, patients with anorexia nervosa scored significantly higher on accuracy and took significantly longer when copying the Rey Complex Figure Task. Caution must be taken when interpreting these findings due to lower-than-expected scores in memory performance in the control group and because of a potential lack of sensitivity in the measures used when assessing this younger population. For neuropsychological functions where no normative data exist, we need a deeper, more thorough knowledge of the developmental trajectory and its assessment in young people in the general population before drawing conclusions in anorexia nervosa.

Prefrontal activity and impaired memory encoding strategies in schizophrenia.

PubMed

Guimond, Synthia; Hawco, Colin; Lepage, Martin

2017-08-01

Schizophrenia patients have significant memory difficulties that have far-reaching implications in their daily life. These impairments are partly attributed to an inability to self-initiate effective memory encoding strategies, but its core neurobiological correlates remain unknown. The current study addresses this critical gap in our knowledge of episodic memory impairments in schizophrenia. Schizophrenia patients (n = 35) and healthy controls (n = 23) underwent a Semantic Encoding Memory Task (SEMT) during an fMRI scan. Brain activity was examined for conditions where participants were a) prompted to use semantic encoding strategies, or b) not prompted but required to self-initiate such strategies. When prompted to use semantic encoding strategies, schizophrenia patients exhibited similar recognition performance and brain activity as healthy controls. However, when required to self-initiate these strategies, patients had significant reduced recognition performance and brain activity in the left dorsolateral prefrontal cortex, as well as in the left temporal gyrus, left superior parietal lobule, and cerebellum. When patients were divided based on performance on the SEMT, the subgroup with more severe deficits in self-initiation also showed greater reduction in left dorsolateral prefrontal activity. These results suggest that impaired self-initiation of elaborative encoding strategies is a driving feature of memory deficits in schizophrenia. We also identified the neural correlates of impaired self-initiation of semantic encoding strategies, in which a failure to activate the left dorsolateral prefrontal cortex plays a key role. These findings provide important new targets in the development of novel treatments aiming to improve memory and ultimately patients' outcome. Copyright © 2017. Published by Elsevier Ltd.

When is working memory important for arithmetic? The impact of strategy and age

PubMed Central

Richardson, Sophie; Hubber, Paula J.; Keeble, Sarah; Gilmore, Camilla

2017-01-01

Our ability to perform arithmetic relies heavily on working memory, the manipulation and maintenance of information in mind. Previous research has found that in adults, procedural strategies, particularly counting, rely on working memory to a greater extent than retrieval strategies. During childhood there are changes in the types of strategies employed, as well as an increase in the accuracy and efficiency of strategy execution. As such it seems likely that the role of working memory in arithmetic may also change, however children and adults have never been directly compared. This study used traditional dual-task methodology, with the addition of a control load condition, to investigate the extent to which working memory requirements for different arithmetic strategies change with age between 9–11 years, 12–14 years and young adulthood. We showed that both children and adults employ working memory when solving arithmetic problems, no matter what strategy they choose. This study highlights the importance of considering working memory in understanding the difficulties that some children and adults have with mathematics, as well as the need to include working memory in theoretical models of mathematical cognition. PMID:29228008

Regulation of Cognitive Processes through Perceived Self-Efficacy.

ERIC Educational Resources Information Center

Bandura, Albert

1989-01-01

Addresses issues concerning the extension of self-efficacy theory to memory functioning. Issues include perceived memory capabilities, memory self-appraisal, personal control over memory functioning, preservation of a favorable sense of memory self-efficacy, and strategies for generalizing the impact of training in memory skills. (RJC)

Short-Term Memory of Children with Mental Retardation: Structural Defects or Control Deficits.

ERIC Educational Resources Information Center

Katims, David S.

The short-term memory of 24 retarded and 24 nonretarded individuals, aged 10 to 14, under conditions of restricted cognitive strategy use was investigated. An attempt was made to determine whether short-term memory difficulties of persons with mental retardation are caused by deficits in voluntary cognitive strategies, such as the organization and…

A Pilot Classroom-Based Study of Attention and Working Memory Strategies for Primary-Aged Students

ERIC Educational Resources Information Center

Colmar, Susan; Davis, Nash; Sheldon, Linda

2016-01-01

An exploratory applied study, using a set of attention and working memory strategies specifically developed for students and named Memory Mates, was completed with normally developing students attending a primary school. Students in one classroom received the intervention, while the other classroom functioned as a control group. The study was…

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.

Organizational strategies mediate nonverbal memory impairment in obsessive-compulsive disorder.

PubMed

Savage, C R; Baer, L; Keuthen, N J; Brown, H D; Rauch, S L; Jenike, M A

1999-04-01

Previous neuropsychological studies of obsessive-compulsive disorder (OCD) have indicated impaired executive functioning and nonverbal memory. The extent to which impaired executive functioning impacts nonverbal memory has not been established. The current study investigated the mediating effects of organizational strategies used when copying a figure on subsequent nonverbal memory for that figure. We examined neuropsychological performance in 20 unmedicated subjects with OCD and 20 matched normal control subjects. Subjects were administered the Rey-Osterrieth Complex Figure Test (RCFT) and neuropsychological tests assessing various aspects of executive function. OCD subjects differed significantly from healthy control subjects in the organizational strategies used to copy the RCFT figure, and they recalled significantly less information on both immediate and delayed testing. Multiple regression analyses indicated that group differences in immediate percent recall were significantly mediated by copy organizational strategies. Further exploratory analyses indicated that organizational problems in OCD may be related to difficulties shifting mental and/or spatial set. Immediate nonverbal memory problems in OCD subjects were mediated by impaired organizational strategies used during the initial copy of the RCFT figure. Thus, the primary deficit was one affecting executive function, which then had a secondary effect on immediate memory. These findings are consistent with current theories proposing frontal-striatal system dysfunction in OCD.

Differential pattern of semantic memory organization between bipolar I and II disorders.

PubMed

Chang, Jae Seung; Choi, Sungwon; Ha, Kyooseob; Ha, Tae Hyon; Cho, Hyun Sang; Choi, Jung Eun; Cha, Boseok; Moon, Eunsoo

2011-06-01

Semantic cognition is one of the key factors in psychosocial functioning. The aim of this study was to explore the differences in pattern of semantic memory organization between euthymic patients with bipolar I and II disorders using the category fluency task. Study participants included 23 euthymic subjects with bipolar I disorder, 23 matched euthymic subjects with bipolar II disorder and 23 matched control subjects. All participants were assessed for verbal learning, recall, learning strategies, and fluency. The combined methods of hierarchical clustering and multidimensional scaling were used to compare the pattern of semantic memory organization among the three groups. Quantitative measures of verbal learning, recall, learning strategies, and fluency did not differ between the three groups. A two-cluster structure of semantic memory organization was identified for the three groups. Semantic structure was more disorganized in the bipolar I disorder group compared to the bipolar II disorder. In addition, patients with bipolar II disorder used less elaborate strategies of semantic memory organization than those of controls. Compared to healthy controls, strategies for categorization in semantic memory appear to be less knowledge-based in patients with bipolar disorders. A differential pattern of semantic memory organization between bipolar I and II disorders indicates a higher risk of cognitive abnormalities in patients with bipolar I disorder compared to patients with bipolar II disorder. Exploring qualitative nature of neuropsychological domains may provide an explanatory insight into the characteristic behaviors of patients with bipolar disorders. Copyright © 2011 Elsevier Inc. All rights reserved.

Mnemonic strategy training improves memory for object location associations in both healthy elderly and patients with amnestic mild cognitive impairment: a randomized, single-blind study

PubMed Central

Hampstead, Benjamin M.; Sathian, K.; Phillips, Pamela A.; Amaraneni, Akshay; Delaune, William R.; Stringer, Anthony Y.

2012-01-01

Objectives To evaluate the efficacy of mnemonic strategy training versus a matched-exposure control condition and also to examine the relationship between training-related gains, neuropsychological abilities, and medial temporal lobe volumetrics in patients with amnestic mild cognitive impairment (aMCI) and age-matched healthy controls. Methods Twenty-three of 45 screened healthy controls and 29 of 42 screened aMCI were randomized to mnemonic strategy or matched-exposure groups. Groups were run in parallel, with participants blind to the other intervention. All participants completed five sessions within two weeks. Memory testing for object-location associations was performed during sessions one and five and at a one-month follow-up. During sessions 2–4, participants received either mnemonic strategy training or a matched number of exposures with corrective feedback for a total of 45 object-location associations. Structural MRI was performed in most participants and medial temporal lobe volumetrics were acquired. Results Twenty-one healthy controls and 28 aMCI patients were included in data analysis. Mnemonic strategy training was significantly more beneficial than matched-exposure immediately after training, p =.006, pη2 = .16, and at one month, p<.001, pη2 = .35, regardless of diagnostic group (healthy controls or aMCI). Although aMCI patients demonstrated gains comparable to the healthy control groups, their overall performance generally remained reduced. Mnemonic strategy-related improvement was positively correlated with baseline memory and executive functioning and negatively with inferior lateral ventricle volume in aMCI patients; no significant relationships were evident in matched-exposure patients. Conclusions Mnemonic strategies effectively improve memory for specific content for at least one month in aMCI. PMID:22409311

Ventral striatum and the evaluation of memory retrieval strategies.

PubMed

Badre, David; Lebrecht, Sophie; Pagliaccio, David; Long, Nicole M; Scimeca, Jason M

2014-09-01

Adaptive memory retrieval requires mechanisms of cognitive control that facilitate the recovery of goal-relevant information. Frontoparietal systems are known to support control of memory retrieval. However, the mechanisms by which the brain acquires, evaluates, and adapts retrieval strategies remain unknown. Here, we provide evidence that ventral striatal activation tracks the success of a retrieval strategy and correlates with subsequent reliance on that strategy. Human participants were scanned with fMRI while performing a lexical decision task. A rule was provided that indicated the likely semantic category of a target word given the category of a preceding prime. Reliance on the rule improved decision-making, as estimated within a drift diffusion framework. Ventral striatal activation tracked the benefit that relying on the rule had on decision-making. Moreover, activation in ventral striatum correlated with a participant's subsequent reliance on the rule. Taken together, these results support a role for ventral striatum in learning and evaluating declarative retrieval strategies.

The Aging Well through Interaction and Scientific Education (AgeWISE) Program.

PubMed

O'Connor, Maureen K; Kraft, Malissa L; Daley, Ryan; Sugarman, Michael A; Clark, Erika L; Scoglio, Arielle A J; Shirk, Steven D

2017-12-08

We conducted a randomized controlled trial of the Aging Well through Interaction and Scientific Education (AgeWISE) program, a 12-week manualized cognitive rehabilitation program designed to provide psychoeducation to older adults about the aging brain, lifestyle factors associated with successful brain aging, and strategies to compensate for age related cognitive decline. Forty-nine cognitively intact participants ≥ 60 years old were randomly assigned to the AgeWISE program (n = 25) or a no-treatment control group (n = 24). Questionnaire data were collected prior to group assignment and post intervention. Two-factor repeated-measures analyses of covariance (ANCOVAs) were used to compare group outcomes. Upon completion, participants in the AgeWISE program reported increases in memory contentment and their sense of control in improving memory; no significant changes were observed in the control group. Surprisingly, participation in the group was not associated with significant changes in knowledge of memory aging, perception of memory ability, or greater use of strategies. The AgeWISE program was successfully implemented and increased participants' memory contentment and their sense of control in improving memory in advancing age. This study supports the use of AgeWISE to improve perspectives on healthy cognitive aging.

Energy-band engineering for tunable memory characteristics through controlled doping of reduced graphene oxide.

PubMed

Han, Su-Ting; Zhou, Ye; Yang, Qing Dan; Zhou, Li; Huang, Long-Biao; Yan, Yan; Lee, Chun-Sing; Roy, Vellaisamy A L

2014-02-25

Tunable memory characteristics are used in multioperational mode circuits where memory cells with various functionalities are needed in one combined device. It is always a challenge to obtain control over threshold voltage for multimode operation. On this regard, we use a strategy of shifting the work function of reduced graphene oxide (rGO) in a controlled manner through doping gold chloride (AuCl3) and obtained a gradient increase of rGO work function. By inserting doped rGO as floating gate, a controlled threshold voltage (Vth) shift has been achieved in both p- and n-type low voltage flexible memory devices with large memory window (up to 4 times for p-type and 8 times for n-type memory devices) in comparison with pristine rGO floating gate memory devices. By proper energy band engineering, we demonstrated a flexible floating gate memory device with larger memory window and controlled threshold voltage shifts.

Source Memory Rehabilitation: A Review Toward Recommendations for Setting Up a Strategy Training Aimed at the "What, Where, and When" of Episodic Retrieval.

PubMed

El Haj, Mohamad; Kessels, Roy P C; Allain, Philippe

2016-01-01

Source memory is a core component of episodic recall as it allows for the reconstruction of contextual details characterizing the acquisition of episodic events. Unlike episodic memory, little is known about source memory rehabilitation. Our review addresses this issue by emphasizing several strategies as useful tools in source memory rehabilitation programs. Four main strategies are likely to improve source recall in amnesic patients-namely, (a) contextual cueing, (b) unitization, (c) errorless learning, and (d) executive function programs. The rationale behind our suggestion is that: (a) reinstating contextual cues during retrieval can serve as retrieval cues and enhance source memory; (b) unitization as an encoding process allows for the integration of several pieces of contextual information into a new single entity; (c) errorless learning may prevent patients from making errors during source learning; and (d) as source memory deteriorations have been classically attributed to executive dysfunction, the rehabilitation of the latter ability is likely to maintain the former ability. Besides these four strategies, our review suggests several additional rehabilitation techniques such as the vanishing cues and spaced retrieval methods. Another additional strategy is the use of electronic devices. By gathering these strategies, our review provides a helpful guideline for clinicians dealing with source memory impairments. Our review further highlights the lack of randomized and controlled studies in the field of source memory rehabilitation.

Neural correlates of verbal associative memory and mnemonic strategy use following childhood traumatic brain injury

PubMed Central

Kramer, Megan E.; Chiu, C.-Y. Peter; Shear, Paula K.; Wade, Shari L.

2010-01-01

Children with traumatic brain injury (TBI) often experience memory deficits, although the nature, functional implication, and recovery trajectory of such difficulties are poorly understood. The present fMRI study examined the neural activation patterns in a group of young children who sustained moderate TBI in early childhood (n = 7), and a group of healthy control children (n = 13) during a verbal paired associate learning (PAL) task that promoted the use of two mnemonic strategies differing in efficacy. The children with TBI demonstrated intact memory performance and were able to successfully utilize the mnemonic strategies. However, the TBI group also demonstrated altered brain activation patterns during the task compared to the control children. These findings suggest early childhood TBI may alter activation within the network of brain regions supporting associative memory even in children who show good behavioral performance. PMID:21188286

Memory-Based Decision-Making with Heuristics: Evidence for a Controlled Activation of Memory Representations

ERIC Educational Resources Information Center

Khader, Patrick H.; Pachur, Thorsten; Meier, Stefanie; Bien, Siegfried; Jost, Kerstin; Rosler, Frank

2011-01-01

Many of our daily decisions are memory based, that is, the attribute information about the decision alternatives has to be recalled. Behavioral studies suggest that for such decisions we often use simple strategies (heuristics) that rely on controlled and limited information search. It is assumed that these heuristics simplify decision-making by…

Selective deficit in spatial memory strategies contrast to intact response strategies in patients with schizophrenia spectrum disorders tested in a virtual navigation task.

PubMed

Wilkins, Leanne K; Girard, Todd A; Konishi, Kyoko; King, Matthew; Herdman, Katherine A; King, Jelena; Christensen, Bruce; Bohbot, Veronique D

2013-11-01

Spatial memory is impaired among persons with schizophrenia (SCZ). However, different strategies may be used to solve most spatial memory and navigation tasks. This study investigated the hypothesis that participants with schizophrenia-spectrum disorders (SSD) would demonstrate differential impairment during acquisition and retrieval of target locations when using a hippocampal-dependent spatial strategy, but not a response strategy, which is more associated with caudate function. Healthy control (CON) and SSD participants were tested using the 4-on-8 virtual maze (4/8VM), a virtual navigation task designed to differentiate between participants' use of spatial and response strategies. Consistent with our predictions, SSD participants demonstrated a differential deficit such that those who navigated using a spatial strategy made more errors and took longer to locate targets. In contrast, SSD participants who spontaneously used a response strategy performed as well as CON participants. The differential pattern of spatial-memory impairment in SSD provides only indirect support for underlying hippocampal dysfunction. These findings emphasize the importance of considering individual strategies when investigating SSD-related memory and navigation performance. Future cognitive intervention protocols may harness SSD participants' intact ability to navigate using a response strategy and/or train the deficient ability to navigate using a spatial strategy to improve navigation and memory abilities in participants with SSD. Copyright © 2013 Wiley Periodicals, Inc.

Strategies for improving memory: a randomized trial of memory groups for older people, including those with mild cognitive impairment.

PubMed

Kinsella, Glynda J; Ames, David; Storey, Elsdon; Ong, Ben; Pike, Kerryn E; Saling, Michael M; Clare, Linda; Mullaly, Elizabeth; Rand, Elizabeth

2016-01-01

Governments are promoting the importance of maintaining cognitive health into older age to minimize risk of cognitive decline and dementia. Older people with amnestic mild cognitive impairment (aMCI) are particularly vulnerable to memory challenges in daily activities and are seeking ways to maintain independent living. To evaluate the effectiveness of memory groups for improving memory strategies and memory ability of older people, especially those with aMCI. 113 healthy older adults (HOA) and 106 adults with aMCI were randomized to a six-week memory group or a waitlist control condition. Outcome was evaluated through knowledge and use of memory strategies, memory ability (self-report and neuropsychological tests), and wellbeing. Assessments included a six-month follow-up. Using intention to treat analyses, there were intervention effects for HOA and aMCI groups in strategy knowledge (HOA: η2= 0.20; aMCI: η2= 0.06), strategy use (HOA: η2= 0.18; aMCI: η2= 0.08), and wellbeing (HOA: η2= 0.11; aMCI: η2= 0.05). There were also intervention effects in the HOA group, but not the aMCI group, in self-reported memory ability (η2= 0.06) and prospective memory tests (η2= 0.02). By six-month follow-up, gains were found on most HOA outcomes. In the aMCI group gains were found in strategy use, and by this stage, gains in prospective memory were also found. Memory groups can engage older people in techniques for maintaining cognitive health and improve memory performance, but more modest benefits are seen for older adults with aMCI.

Randomized controlled trial of a healthy brain ageing cognitive training program: effects on memory, mood, and sleep.

PubMed

Diamond, Keri; Mowszowski, Loren; Cockayne, Nicole; Norrie, Louisa; Paradise, Matthew; Hermens, Daniel F; Lewis, Simon J G; Hickie, Ian B; Naismith, Sharon L

2015-01-01

With the rise in the ageing population and absence of a cure for dementia, cost-effective prevention strategies for those 'at risk' of dementia including those with depression and/or mild cognitive impairment are urgently required. This study evaluated the efficacy of a multifaceted Healthy Brain Ageing Cognitive Training (HBA-CT) program for older adults 'at risk' of dementia. Using a single-blinded design, 64 participants (mean age = 66.5 years, SD = 8.6) were randomized to an immediate treatment (HBA-CT) or treatment-as-usual control arm. The HBA-CT intervention was conducted twice-weekly for seven weeks and comprised group-based psychoeducation about cognitive strategies and modifiable lifestyle factors pertaining to healthy brain ageing, and computerized cognitive training. In comparison to the treatment-as-usual control arm, the HBA-CT program was associated with improvements in verbal memory (p = 0.03), self-reported memory (p = 0.03), mood (p = 0.01), and sleep (p = 0.01). While the improvements in memory (p = 0.03) and sleep (p = 0.02) remained after controlling for improvements in mood, only a trend in verbal memory improvement was apparent after controlling for sleep. The HBA-CT program improves cognitive, mood, and sleep functions in older adults 'at risk' of dementia, and therefore offers promise as a secondary prevention strategy.

Temporal information processing in short- and long-term memory of patients with schizophrenia.

PubMed

Landgraf, Steffen; Steingen, Joerg; Eppert, Yvonne; Niedermeyer, Ulrich; van der Meer, Elke; Krueger, Frank

2011-01-01

Cognitive deficits of patients with schizophrenia have been largely recognized as core symptoms of the disorder. One neglected factor that contributes to these deficits is the comprehension of time. In the present study, we assessed temporal information processing and manipulation from short- and long-term memory in 34 patients with chronic schizophrenia and 34 matched healthy controls. On the short-term memory temporal-order reconstruction task, an incidental or intentional learning strategy was deployed. Patients showed worse overall performance than healthy controls. The intentional learning strategy led to dissociable performance improvement in both groups. Whereas healthy controls improved on a performance measure (serial organization), patients improved on an error measure (inappropriate semantic clustering) when using the intentional instead of the incidental learning strategy. On the long-term memory script-generation task, routine and non-routine events of everyday activities (e.g., buying groceries) had to be generated in either chronological or inverted temporal order. Patients were slower than controls at generating events in the chronological routine condition only. They also committed more sequencing and boundary errors in the inverted conditions. The number of irrelevant events was higher in patients in the chronological, non-routine condition. These results suggest that patients with schizophrenia imprecisely access temporal information from short- and long-term memory. In short-term memory, processing of temporal information led to a reduction in errors rather than, as was the case in healthy controls, to an improvement in temporal-order recall. When accessing temporal information from long-term memory, patients were slower and committed more sequencing, boundary, and intrusion errors. Together, these results suggest that time information can be accessed and processed only imprecisely by patients who provide evidence for impaired time comprehension. This could contribute to symptomatic cognitive deficits and strategic inefficiency in schizophrenia.

Variable Memory Strategy Use in Children's Adaptive Intratask Learning Behavior: Developmental Changes and Working Memory Influences in Free Recall

ERIC Educational Resources Information Center

Lehmann, Martin; Hasselhorn, Marcus

2007-01-01

Variability in strategy use within single trials in free recall was analyzed longitudinally from second to fourth grades (ages 8-10 years). To control for practice effects another sample of fourth graders was included (age 10 years). Video analyses revealed that children employed different strategies when preparing for free recall. A gradual shift…

Short-term memory and strategy use in children with insulin-dependent diabetes mellitus.

PubMed

Wolters, C A; Yu, S L; Hagen, J W; Kail, R

1996-12-01

The present study was designed to examine recall and rehearsal in short-term memory among children with insulin-dependent diabetes mellitus (IDDM). Children with onset of IDDM before age 5 years, children with onset after 5 years, and children without IDDM were administered a measure of short-term memory that provides information about rehearsal as well as level of recall. Children with later onset of diabetes and children without IDDM were expected to recall more words and use more effective rehearsal strategies than children with early onset of diabetes. Results indicate that children diagnosed with IDDM early in life used similar rehearsal strategies but recalled fewer words than children with later onset of diabetes and children without IDDM. In addition, results provide evidence that children who are in poor control of their diabetes did not use strategies designed to increase recall as often, or as well as, children in better control of their diabetes.

Organizational strategy influence on visual memory performance after stroke: cortical/subcortical and left/right hemisphere contrasts.

PubMed

Lange, G; Waked, W; Kirshblum, S; DeLuca, J

2000-01-01

To examine how organizational strategy at encoding influences visual memory performance in stroke patients. Case control study. Postacute rehabilitation hospital. Stroke patients with right hemisphere damage (n = 20) versus left hemisphere damage (n = 15), and stroke patients with cortical damage (n = 11) versus subcortical damage (n = 19). Organizational strategy scores, recall performance on the Rey-Osterrieth Complex Figure (ROCF). Results demonstrated significantly greater organizational impairment and less accurate copy performance (i.e., encoding of visuospatial information on the ROCF) in the right compared to the left hemisphere group, and in the cortical relative to the subcortical group. Organizational strategy and copy accuracy scores were significantly related to each other. The absolute amount of immediate and delayed recall was significantly associated with poor organizational strategy scores. However, relative to the amount of visual information originally encoded, memory performances did not differ between groups. These findings suggest that visual memory impairments after stroke may be caused by a lack of organizational strategy affecting information encoding, rather than an impairment in memory storage or retrieval.

Teachers' Memories of Disciplinary Control Strategies from Their Own School Days

ERIC Educational Resources Information Center

DePalma, Renee; Membiela, Pedro; Pazos, Mercedes Suarez

2011-01-01

This article provides a vision of school disciplinary strategies as provided by childhood school memories of practicing or unemployed teachers. This narrative approach allows us to understand the school and its daily routines and rituals from an insiders' point of view, drawing upon the double perspective teachers employ when reflecting on their…

Working memory in children and adolescents with Down syndrome: evidence from a colour memory experiment.

PubMed

Laws, Glynis

2002-03-01

This paper reports information on the visual and verbal short-term memory of individuals with Down syndrome. Colour memory in 16 children and adolescents with Down syndrome was compared with that of 16 typically developing children matched for receptive vocabulary. It was suggested that focal colours should be remembered more successfully than non-focal colours on the basis that the former could be remembered using a verbal recoding strategy. However, children with Down syndrome, for whom a deficit in verbal short-term memory makes the use of such a strategy unlikely, should remember focal and non-focal colours equally well. More importantly, if individuals with Down syndrome have more developed visual memory abilities than control children, they should outperform them in recognising non-focal colours. Although the group with Down syndrome demonstrated significantly better Corsi blocks performance than controls, and displayed similar levels of colour knowledge, no advantage for colour memory was found. Non-focal colours were remembered by individuals with Down syndrome as successfully as focal colours but there was no indication of a visual memory advantage over controls. Focal colours were remembered significantly more successfully than non-focal colours by the typically developing children. Their focal colour memory was significantly related to digit span, but only Corsi span was related to focal colour memory in the group with Down syndrome.

Ventral Striatum and the Evaluation of Memory Retrieval Strategies

PubMed Central

Badre, David; Lebrecht, Sophie; Pagliaccio, David; Long, Nicole M.; Scimeca, Jason M.

2015-01-01

Adaptive memory retrieval requires mechanisms of cognitive control that facilitate the recovery of goal-relevant information. Frontoparietal systems are known to support control of memory retrieval. However, the mechanisms by which the brain acquires, evaluates, and adapts retrieval strategies remain unknown. Here, we provide evidence that ventral striatal activation tracks the success of a retrieval strategy and correlates with subsequent reliance on that strategy. Human participants were scanned with fMRI while performing a lexical decision task. A rule was provided that indicated the likely semantic category of a target word given the category of a preceding prime. Reliance on the rule improved decision-making, as estimated within a drift diffusion framework. Ventral striatal activation tracked the benefit that relying on the rule had on decision-making. Moreover, activation in ventral striatum correlated with a participant’s subsequent reliance on the rule. Taken together, these results support a role for ventral striatum in learning and evaluating declarative retrieval strategies. PMID:24564466

Strategy in short-term memory for pictures in childhood: a near-infrared spectroscopy study.

PubMed

Sanefuji, Masafumi; Takada, Yui; Kimura, Naoko; Torisu, Hiroyuki; Kira, Ryutaro; Ishizaki, Yoshito; Hara, Toshiro

2011-02-01

In Baddeley's working memory model, verbalizable visual material such as pictures are recoded into a phonological form and then rehearsed, while auditory material is rehearsed directly. The recoding and rehearsal processes are mediated by articulatory control process in the left ventrolateral prefrontal cortex (VLPFC). Developmentally, the phonological strategy for serially-presented visual material emerges around 7 years of age, while that for auditory material is consistently present by 4 years of age. However, the strategy change may actually be correlated with memory ability as this usually increases with age. To investigate the relationship between the strategy for pictures and memory ability, we monitored the left VLPFC activation in 5 to 11 year-old children during free recall of visually- or auditorily-presented familiar objects using event-related near-infrared spectroscopy. We hypothesized that the phonological strategy of rehearsal and recoding for visual material would provoke greater activation than only rehearsal for auditory material in the left VLPFC. Therefore, we presumed that the activation difference for visual material compared with auditory material in the left VLPFC may represent the tendency to use a phonological strategy. We found that the activation difference in the left VLPFC showed a significant positive correlation with memory ability but not with age, suggesting that children with high memory ability make more use of phonological strategy for pictures. The present study provides functional evidence that the strategy in short-term memory for pictures shifts gradually from non-phonological to phonological as memory ability increases in childhood. Copyright © 2010 Elsevier Inc. All rights reserved.

Goal-Driven Autonomy and Robust Architecture for Long-Duration Missions (Year 1: 1 July 2013 - 31 July 2014)

DTIC Science & Technology

2014-09-30

Mental Domain = Ω Goal Management goal change goal input World =Ψ Memory Mission & Goals( ) World Model (-Ψ) Episodic Memory Semantic Memory ...Activations Trace Meta-Level Control Introspective Monitoring Memory Reasoning Trace ( ) Strategies Episodic Memory Metaknowledge Self Model...it is from incorrect or missing memory associations (i.e., indices). Similarly, correct information may exist in the input stream, but may not be

Do organizational strategies mediate nonverbal memory impairment in drug-naïve patients with obsessive-compulsive disorder?

PubMed

Shin, Na Young; Kang, Do-Hyung; Choi, Jung-Seok; Jung, Myung Hun; Jang, Joon Hwan; Kwon, Jun Soo

2010-07-01

The present study aimed to examine nonverbal memory and organizational skill functions in psychotropic-naïve patients with OCD. Forty-one drug-naïve, 41 medicated OCD patients and 41 healthy controls, all of whom were matched for gender, age, education and intelligence, were included in the study. The Rey-Osterrieth Complex Figure Test (RCFT) was administered to evaluate nonverbal memory ability and organizational skill. OCD patients demonstrated impaired nonverbal memory irrespective of medication status (F = 6.54, p < .01, eta(2)p = .098 for immediate recall; F = 7.76, p < .01, eta(2)p = .114 for delayed recall). Medicated patients showed deficits in organizational strategies (eta(2)p = .079), which mediated nonverbal memory impairment (Z = -2.20, p = .027). The difference of organizational skill between drug-naïve and control groups did not reach statistical significance (eta(2)p = .054) and the association between organization and nonverbal memory was weak in the drug-naïve sample (Z = -1.74, = .081). There was no significant difference between the patient groups in RCFT indices. Our findings suggest that the organizational strategies may not be an effective mediator of nonverbal memory impairment in OCD and indicate that the clinical characteristics may be important to be considered in future research. Further studies are needed to improve understanding of the nature of nonverbal memory dysfunction in OCD.

Cognitive rehabilitation for memory deficits following stroke.

PubMed

Majid, M J; Lincoln, N B; Weyman, N

2000-01-01

Memory problems occur following stroke. Cognitive rehabilitation programmes are provided to retrain memory function or to teach patients strategies to cope despite memory impairment. To determine the effects of cognitive rehabilitation for memory problems following stroke. We searched the Cochrane Stroke Group Trials Register, Medline, EMBASE, CINHAL and CLIN PSYCH databases and reference lists from relevant articles. Date of most recent searches: December 1998. Controlled trials of memory retraining in stroke. Studies with mixed aetiology groups were excluded unless they had more than 75% of stroke patients or separate data were available for the stroke patients. Two reviewers extracted trial data and assessed trial quality. Reviewers contacted investigators for further details of trials. One trial was identified with 12 participants. This showed memory strategy training had no significant effect on memory impairment or subjective memory complaints. There is insufficient evidence to support or refute the effectiveness of cognitive rehabilitation for memory problems after stroke.

Reading Time Allocation Strategies and Working Memory Using Rapid Serial Visual Presentation

ERIC Educational Resources Information Center

Busler, Jessica N.; Lazarte, Alejandro A.

2017-01-01

Rapid serial visual presentation (RSVP) is a useful method for controlling the timing of text presentations and studying how readers' characteristics, such as working memory (WM) and reading strategies for time allocation, influence text recall. In the current study, a modified version of RSVP (Moving Window RSVP [MW-RSVP]) was used to induce…

The Role of Memory in Early Literacy Acquisition.

ERIC Educational Resources Information Center

Stone, Sandra J.

Emerging literacy is a developmental process which is closely tied to the child's developing cognitive processes. The interaction of memory and emerging literacy can be discussed in the context of Marie Clay's Reading Recovery model. Memory types, encoding and retrieval, strategy use, and executive control/expectancies are components of cognitive…

Training working memory in older adults: Is there an advantage of using strategies?

PubMed

Borella, Erika; Carretti, Barbara; Sciore, Roberta; Capotosto, Emanuela; Taconnat, Laurence; Cornoldi, Cesare; De Beni, Rossana

2017-03-01

The purpose of the present study was to test the efficacy of a working memory (WM) training in elderly people, and to compare the effects of a WM training based on an adaptive procedure with one combining the same procedure with the use of a strategy, based on the construction of visual mental images. Eighteen older adults received training with a WM task (the WM group), another 18 received the same WM training and were also taught to use a visual imagery strategy (the WM + Strategy group), and another 18 served as active controls. Training-related gains in the WM (criterion) task and transfer effects on measures of verbal and visuospatial WM, short-term memory (STM), processing speed, and reasoning were considered. Training gains and transfer effects were also assessed after 6 months. After the training, both the trained groups performed better than the control group in the WM criterion task, and maintained these gains 6 months later; they also showed immediate transfer effects on processing speed. The two trained groups also outperformed the control group in the long term in the WM tasks, in one of the STM tasks (backward span task), and in the processing speed measure. Long-term large effect sizes were found for all the tasks involving memory processes in the WM + Strategy group, but only for the processing speed task in the WM group. Findings are discussed in terms of the benefits and limits of teaching older people a strategy in combination with an adaptive WM training. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Strategic memory in adults with anorexia nervosa: are there similarities to obsessive compulsive spectrum disorders?

PubMed

Sherman, Bonnie J; Savage, Cary R; Eddy, Kamryn T; Blais, Mark A; Deckersbach, Thilo; Jackson, Safia C; Franko, Debra L; Rauch, Scott L; Herzog, David B

2006-09-01

There is growing interest in the relationship between anorexia nervosa (AN) and obsessive-compulsive (OC) spectrum disorders (e.g., OCD, body dysmorphic disorder [BDD]). Previous neuropsychological investigations of OC spectrum disorders have identified problems with the efficient use of strategy on complex measures of learning and memory. This study evaluated nonverbal strategic memory in AN outpatients using an approach previously applied to OC spectrum disorders. Eighteen patients with AN and 19 healthy control participants completed the Rey-Osterrieth Complex Figure Test (RCFT), a widely used measure of nonverbal strategic planning, learning, and memory. Individuals with AN differed significantly from healthy controls in the organizational strategies used to copy the RCFT figure, and they recalled significantly less information on both immediate and delayed testing. Multiple regression analyses indicated that group differences in learning were mediated by copy organizational strategies. These results are identical to study findings in OCD and BDD, indicating important shared neuropsychological features among AN and these OC spectrum disorders. As in OCD and BDD, the essential cognitive deficit in AN was impaired use of organizational strategies, which may inform our understanding of the pathophysiology of AN and potentially offer treatment implications. Copyright (c) 2006 by Wiley Periodicals, Inc.

Free recall of word lists under total sleep deprivation and after recovery sleep.

PubMed

de Almeida Valverde Zanini, Gislaine; Tufik, Sérgio; Andersen, Monica Levy; da Silva, Raquel Cristina Martins; Bueno, Orlando Francisco Amodeo; Rodrigues, Camila Cruz; Pompéia, Sabine

2012-02-01

One task that has been used to assess memory effects of prior total sleep deprivation (TSD) is the immediate free recall of word lists; however, results have been mixed. A possible explanation for this is task impurity, since recall of words from different serial positions reflects use of distinct types of memory (last words: short-term memory; first and intermediate words: episodic memory). Here we studied the effects of 2 nights of TSD on immediate free recall of semantically unrelated word lists considering the serial position curve. Random allocation to a 2-night TSD protocol followed by one night of recovery sleep or to a control group. Study conducted under continuous behavioral monitoring. 24 young, healthy male volunteers. 2 nights of total sleep deprivation (TSD) and one night of recovery sleep. Participants were shown five 15 unrelated word-lists at baseline, after one and 2 nights of TSD, and after one night of recovery sleep. We also investigated the development of recall strategies (learning) and susceptibility to interference from previous lists. No free recall impairment occurred during TSD, irrespective of serial position. Interference was unchanged. Both groups developed recall strategies, but task learning occurred earlier in controls and was evident in the TSD group only after sleep recovery. Prior TSD spared episodic memory, short-term phonological memory, and interference, allowed the development of recall strategies, but may have decreased the advantage of using these strategies, which returned to normal after recovery sleep.

Variable memory strategy use in children's adaptive intratask learning behavior: developmental changes and working memory influences in free recall.

PubMed

Lehmann, Martin; Hasselhorn, Marcus

2007-01-01

Variability in strategy use within single trials in free recall was analyzed longitudinally from second to fourth grades (ages 8-10 years). To control for practice effects another sample of fourth graders was included (age 10 years). Video analyses revealed that children employed different strategies when preparing for free recall. A gradual shift from labeling to cumulative rehearsal was present both with increasing age and across different list positions. Whereas cumulative rehearsal was frequent at early list positions, labeling was dominant at later list portions. Working memory capacity predicted the extent of cumulative rehearsal usage, which became more efficient with increasing age. Results are discussed in the context of the adaptive strategy choice model.

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.

Can Training in a Real-Time Strategy Videogame Attenuate Cognitive Decline in Older Adults?

PubMed Central

Basak, Chandramallika; Boot, Walter R.; Voss, Michelle W.; Kramer, Arthur F.

2014-01-01

Declines in various cognitive abilities, particularly executive control functions, are observed in older adults. An important goal of cognitive training is to slow or reverse these age-related declines. However, opinion is divided in the literature regarding whether cognitive training can engender transfer to a variety of cognitive skills in older adults. Yet, recent research indicates that videogame training of young adults may engender broad transfer to skills of visual attention. In the current study, we used a real-time strategy videogame to attempt to train executive functions in older adults, such as working memory, task switching, short-term memory, inhibition, and reasoning. Older adults were either trained in a real-time strategy videogame for 23.5 hours (RON, n=20) or not (CONTROLS, n=20). A battery of cognitive tasks, including tasks of executive control and visuo-spatial skills, were assessed before, during, and after video game training. The trainees improved significantly in the measures of game performance. They also improved significantly more than the controls in a subset of the cognitive tasks, such as task switching, working memory, visual short term memory, and mental rotation. Trends in improvement were also observed, for the video game trainees, in inhibition and reasoning. Individual differences in changes in game performance were correlated with improvements in task-switching. The study has implications for the enhancement of executive control processes of older adults. PMID:19140648

Contribution of organizational strategy to verbal learning and memory in adults with attention-deficit/hyperactivity disorder.

PubMed

Roth, Robert M; Wishart, Heather A; Flashman, Laura A; Riordan, Henry J; Huey, Leighton; Saykin, Andrew J

2004-01-01

Statistical mediation modeling was used to test the hypothesis that poor use of a semantic organizational strategy contributes to verbal learning and memory deficits in adults with attention-deficit/hyperactivity disorder (ADHD). Comparison of 28 adults with ADHD and 34 healthy controls revealed lower performance by the ADHD group on tests of verbal learning and memory, sustained attention, and use of semantic organization during encoding. Mediation modeling indicated that state anxiety, but not semantic organization, significantly contributed to the prediction of both learning and delayed recall in the ADHD group. The pattern of findings suggests that decreased verbal learning and memory in adult ADHD is due in part to situational anxiety and not to poor use of organizational strategies during encoding. ((c) 2004 APA, all rights reserved)

Persistent non-verbal memory impairment in remitted major depression - caused by encoding deficits?

PubMed

Behnken, Andreas; Schöning, Sonja; Gerss, Joachim; Konrad, Carsten; de Jong-Meyer, Renate; Zwanzger, Peter; Arolt, Volker

2010-04-01

While neuropsychological impairments are well described in acute phases of major depressive disorders (MDD), little is known about the neuropsychological profile in remission. There is evidence for episodic memory impairments in both acute depressed and remitted patients with MDD. Learning and memory depend on individuals' ability to organize information during learning. This study investigates non-verbal memory functions in remitted MDD and whether nonverbal memory performance is mediated by organizational strategies whilst learning. 30 well-characterized fully remitted individuals with unipolar MDD and 30 healthy controls matching in age, sex and education were investigated. Non-verbal learning and memory were measured by the Rey-Osterrieth-Complex-Figure-Test (RCFT). The RCFT provides measures of planning, organizational skills, perceptual and non-verbal memory functions. For assessing the mediating effects of organizational strategies, we used the Savage Organizational Score. Compared to healthy controls, participants with remitted MDD showed more deficits in their non-verbal memory function. Moreover, participants with remitted MDD demonstrated difficulties in organizing non-verbal information appropriately during learning. In contrast, no impairments regarding visual-spatial functions in remitted MDD were observed. Except for one patient, all the others were taking psychopharmacological medication. The neuropsychological function was solely investigated in the remitted phase of MDD. Individuals with MDD in remission showed persistent non-verbal memory impairments, modulated by a deficient use of organizational strategies during encoding. Therefore, our results strongly argue for additional therapeutic interventions in order to improve these remaining deficits in cognitive function. Copyright 2009 Elsevier B.V. All rights reserved.

Cognitive strategy interventions improve word problem solving and working memory in children with math disabilities.

PubMed

Swanson, H Lee

2015-01-01

This study investigated the role of strategy instruction and working memory capacity (WMC) on problem solving solution accuracy in children with and without math disabilities (MD). Children in grade 3 (N = 204) with and without MD subdivided into high and low WMC were randomly assigned to 1 of 4 conditions: verbal strategies (e.g., underlining question sentence), visual strategies (e.g., correctly placing numbers in diagrams), verbal + visual strategies, and an untreated control. The dependent measures for training were problem solving accuracy and two working memory transfer measures (operation span and visual-spatial span). Three major findings emerged: (1) strategy instruction facilitated solution accuracy but the effects of strategy instruction were moderated by WMC, (2) some strategies yielded higher post-test scores than others, but these findings were qualified as to whether children were at risk for MD, and (3) strategy training on problem solving measures facilitated transfer to working memory measures. The main findings were that children with MD, but high WM spans, were more likely to benefit from strategy conditions on target and transfer measures than children with lower WMC. The results suggest that WMC moderates the influence of cognitive strategies on both the targeted and non-targeted measures.

Cognitive strategy interventions improve word problem solving and working memory in children with math disabilities

PubMed Central

Swanson, H. Lee

2015-01-01

This study investigated the role of strategy instruction and working memory capacity (WMC) on problem solving solution accuracy in children with and without math disabilities (MD). Children in grade 3 (N = 204) with and without MD subdivided into high and low WMC were randomly assigned to 1 of 4 conditions: verbal strategies (e.g., underlining question sentence), visual strategies (e.g., correctly placing numbers in diagrams), verbal + visual strategies, and an untreated control. The dependent measures for training were problem solving accuracy and two working memory transfer measures (operation span and visual-spatial span). Three major findings emerged: (1) strategy instruction facilitated solution accuracy but the effects of strategy instruction were moderated by WMC, (2) some strategies yielded higher post-test scores than others, but these findings were qualified as to whether children were at risk for MD, and (3) strategy training on problem solving measures facilitated transfer to working memory measures. The main findings were that children with MD, but high WM spans, were more likely to benefit from strategy conditions on target and transfer measures than children with lower WMC. The results suggest that WMC moderates the influence of cognitive strategies on both the targeted and non-targeted measures. PMID:26300803

A Connectionist/Control Architecture for Working Memory and Workload: Why Working Memory Is Not 7+ /-2

DTIC Science & Technology

1987-09-29

load on the centra and regional controllers. Strategy #S: Reduce message Chase. W.G., & Ericsson. K.A. ( 1082 ). Skill andInterference of concurrently...bypsycholocy Lf learning and motivation. Vol. Ia. strengthening region. to,.region connections on theNeYokAcdmcPs. innerlooip. Crowder, R.G. ( 1082

Feedforward hysteresis compensation in trajectory control of piezoelectrically-driven nanostagers

NASA Astrophysics Data System (ADS)

Bashash, Saeid; Jalili, Nader

2006-03-01

Complex structural nonlinearities of piezoelectric materials drastically degrade their performance in variety of micro- and nano-positioning applications. From the precision positioning and control perspective, the multi-path time-history dependent hysteresis phenomenon is the most concerned nonlinearity in piezoelectric actuators to be analyzed. To realize the underlying physics of this phenomenon and to develop an efficient compensation strategy, the intelligent properties of hysteresis with the effects of non-local memories are discussed. Through performing a set of experiments on a piezoelectrically-driven nanostager with high resolution capacitive position sensor, it is shown that for the precise prediction of hysteresis path, certain memory units are required to store the previous hysteresis trajectory data. Based on the experimental observations, a constitutive memory-based mathematical modeling framework is developed and trained for the precise prediction of hysteresis path for arbitrarily assigned input profiles. Using the inverse hysteresis model, a feedforward control strategy is then developed and implemented on the nanostager to compensate for the system everpresent nonlinearity. Experimental results demonstrate that the controller remarkably eliminates the nonlinear effect if memory units are sufficiently chosen for the inverse model.

Controlled encoding strategies in memory tests in lithium patients.

PubMed

Opgenoorth, E; Karlick-Bolten, E

1986-03-01

The "levels of processing" theory (Craik and Lockhart) and "dual coding" theory (Paivio) provide new aspects for clinical memory research work. Therefore, an incidental learning paradigm on the basis of these two theoretical approaches was chosen to test aspects of memory performances with lithium therapy. Results of two experiments, with controlled non-semantic processing (rating experiment "comparison of size") and additive semantic processing (rating "living--non-living") indicate a slight reduction in recall (Fig. 1) and recognition performance (Fig. 2) in lithium patients. Effects on encoding strategies are of equal quality in patients and healthy subjects (Tab. 1, 2) but performance differs between both groups: poorer systematic benefit from within code repetitions ("word-word" items, "picture-picture" items) and dual coding (repeated variable item presentation "picture-word") is obtained. The less efficient encoding strategies in the speeded task are discussed with respect to cognitive rigidity and slowing of performance by emotional states. This investigation of so-called "memory deficits" with lithium is an attempt to explore impairments at an early stage of processing; the characterization of the perceptual cognitive analysis seems useful for further clinical research work on this topic.

Verbal memory in drug-naive, newly diagnosed Parkinson's disease. The retrieval deficit hypothesis revisited.

PubMed

Brønnick, Kolbjørn; Alves, Guido; Aarsland, Dag; Tysnes, Ole-Bjørn; Larsen, Jan Petter

2011-01-01

The retrieval deficit hypothesis on memory impairment in patients with Parkinson's disease (PD) implies a selective impairment in recall of learned material with normal encoding, retention, and recognition. This hypothesis has been challenged by new data. We have therefore investigated verbal memory and learning in a large sample of newly diagnosed, drug naïve, non-demented patients with PD. From a sample of patients with PD from the Norwegian ParkWest study, 133 PD patients and 133 controls matched on sex, age, and education were included. The California Verbal Learning Test-2 (CVLT-2) was used to assess verbal memory. Patients performed significantly worse than controls on free and cued recall as well as on recognition memory. Patients used the semantic clustering learning strategy significantly less extensively than the controls and the learning slope of the PD patients was significantly less steep. There was no difference in retention when controlling for encoding. Patients did not perform better on the recognition measure or on cued recall (d-prime), as compared to free recall. Executive functions explained a substantial part of the memory deficits. This study suggests that memory impairment in drug naïve early PD to a large degree is a deficit of learning/ encoding and not of retention or retrieval. An implication is that the retrieval deficit hypothesis should be moderated in its general form. Executive deficits and less extensive use of the efficient semantic clustering learning strategy had a strong impact on learning and memory. (c) 2010 APA, all rights reserved.

Ezh2 phosphorylation state determines its capacity to maintain CD8+ T memory precursors for antitumor immunity.

PubMed

He, Shan; Liu, Yongnian; Meng, Lijun; Sun, Hongxing; Wang, Ying; Ji, Yun; Purushe, Janaki; Chen, Pan; Li, Changhong; Madzo, Jozef; Issa, Jean-Pierre; Soboloff, Jonathan; Reshef, Ran; Moore, Bethany; Gattinoni, Luca; Zhang, Yi

2017-12-14

Memory T cells sustain effector T-cell production while self-renewing in reaction to persistent antigen; yet, excessive expansion reduces memory potential and impairs antitumor immunity. Epigenetic mechanisms are thought to be important for balancing effector and memory differentiation; however, the epigenetic regulator(s) underpinning this process remains unknown. Herein, we show that the histone methyltransferase Ezh2 controls CD8 + T memory precursor formation and antitumor activity. Ezh2 activates Id3 while silencing Id2, Prdm1 and Eomes, promoting the expansion of memory precursor cells and their differentiation into functional memory cells. Akt activation phosphorylates Ezh2 and decreases its control of these transcriptional programs, causing enhanced effector differentiation at the expense of T memory precursors. Engineering T cells with an Akt-insensitive Ezh2 mutant markedly improves their memory potential and capability of controlling tumor growth compared to transiently inhibiting Akt. These findings establish Akt-mediated phosphorylation of Ezh2 as a critical target to potentiate antitumor immunotherapeutic strategies.

Strategies for memory-based decision making: Modeling behavioral and neural signatures within a cognitive architecture.

PubMed

Fechner, Hanna B; Pachur, Thorsten; Schooler, Lael J; Mehlhorn, Katja; Battal, Ceren; Volz, Kirsten G; Borst, Jelmer P

2016-12-01

How do people use memories to make inferences about real-world objects? We tested three strategies based on predicted patterns of response times and blood-oxygen-level-dependent (BOLD) responses: one strategy that relies solely on recognition memory, a second that retrieves additional knowledge, and a third, lexicographic (i.e., sequential) strategy, that considers knowledge conditionally on the evidence obtained from recognition memory. We implemented the strategies as computational models within the Adaptive Control of Thought-Rational (ACT-R) cognitive architecture, which allowed us to derive behavioral and neural predictions that we then compared to the results of a functional magnetic resonance imaging (fMRI) study in which participants inferred which of two cities is larger. Overall, versions of the lexicographic strategy, according to which knowledge about many but not all alternatives is searched, provided the best account of the joint patterns of response times and BOLD responses. These results provide insights into the interplay between recognition and additional knowledge in memory, hinting at an adaptive use of these two sources of information in decision making. The results highlight the usefulness of implementing models of decision making within a cognitive architecture to derive predictions on the behavioral and neural level. Copyright © 2016 Elsevier B.V. All rights reserved.

The Dorsolateral Prefrontal Cortex Plays a Role in Self-Initiated Elaborative Cognitive Processing during Episodic Memory Encoding: rTMS Evidence

PubMed Central

Hawco, Colin; Berlim, Marcelo T.; Lepage, Martin

2013-01-01

During episodic memory encoding, elaborative cognitive processing can improve later recall or recognition. While multiple studies examined the neural correlates of encoding strategies, few studies have explicitly focused on the self-initiation of elaborative encoding. Repetitive transcranial magnetic stimulation (rTMS), a method which can transiently disrupt neural activity, was administered during an associative encoding task. rTMS was either applied to the left dorsolateral prefrontal cortex (DLPFC) or to the vertex (a control region not involved in memory encoding) during presentation of pairs of words. Pairs could be semantically related or not related. Two encoding instructions were given, either cueing participants to analyze semantic relationships (cued condition), or to memorize the pair without any specific strategy cues (the self-initiated condition). Participants filled out a questionnaire regarding their use of memory strategies and performed a cued-recall task. We hypothesized that if the DLPFC plays a role in the self-initiation of elaborative encoding we would observe a reduction in memory performance in the self-initiated condition, particularly for related. We found a significant correlation between the effects of rTMS and strategy use, only in the self-initiated condition with related pairs. High strategy users showed reduced performance following DLPFC stimulation, while low strategy users tended to show increased recall following DLPFC stimulation during encoding. These results suggest the left DLPFC may be involved in the self-initiation of memory strategy use, and individuals may utilize different neural networks depending on their use of encoding strategies. PMID:24040072

Rule-Based Category Learning in Children: The Role of Age and Executive Functioning

PubMed Central

Rabi, Rahel; Minda, John Paul

2014-01-01

Rule-based category learning was examined in 4–11 year-olds and adults. Participants were asked to learn a set of novel perceptual categories in a classification learning task. Categorization performance improved with age, with younger children showing the strongest rule-based deficit relative to older children and adults. Model-based analyses provided insight regarding the type of strategy being used to solve the categorization task, demonstrating that the use of the task appropriate strategy increased with age. When children and adults who identified the correct categorization rule were compared, the performance deficit was no longer evident. Executive functions were also measured. While both working memory and inhibitory control were related to rule-based categorization and improved with age, working memory specifically was found to marginally mediate the age-related improvements in categorization. When analyses focused only on the sample of children, results showed that working memory ability and inhibitory control were associated with categorization performance and strategy use. The current findings track changes in categorization performance across childhood, demonstrating at which points performance begins to mature and resemble that of adults. Additionally, findings highlight the potential role that working memory and inhibitory control may play in rule-based category learning. PMID:24489658

The effects of velocity difference changes with memory on the dynamics characteristics and fuel economy of traffic flow

NASA Astrophysics Data System (ADS)

Yu, Shaowei; Zhao, Xiangmo; Xu, Zhigang; Zhang, Licheng

2016-11-01

To evaluate the effects of velocity difference changes with memory in the intelligent transportation environment on the dynamics and fuel consumptions of traffic flow, we first investigate the linkage between velocity difference changes with memory and car-following behaviors with the measured data in cities, and then propose an improved cooperative car-following model considering multiple velocity difference changes with memory in the cooperative adaptive cruise control strategy, finally carry out several numerical simulations under the periodic boundary condition and at signalized intersections to explore how velocity difference changes with memory affect car's velocity, velocity fluctuation, acceleration and fuel consumptions in the intelligent transportation environment. The results show that velocity difference changes with memory have obvious effects on car-following behaviors, that the improved cooperative car-following model can describe the phase transition of traffic flow and estimate the evolution of traffic congestion, that the stability and fuel economy of traffic flow simulated by the improved car-following model with velocity difference changes with memory is obviously superior to those without velocity difference changes, and that taking velocity difference changes with memory into account in designing the advanced adaptive cruise control strategy can significantly improve the stability and fuel economy of traffic flow.

[An effect of priming task repetition on memory processes in an epileptic with amnesia].

PubMed

Murata, S; Chiba, T; Wada, M; Kitajima, S; Kanoh, M

1991-01-01

The purpose of this paper is to investigate memory processes in an epileptic with amnesia. Selective impairment of memory in organic amnesia has been reported in some clinical observations. They also demonstrated that organic amnesia can retain some aspects of learning experience, despite their inability to recollect them. We investigated an effect of priming task repetition on memory processes in a female with organic amnesia aged 28 (probable encephalitic patient) and eight control college students aged 20-26. In this paper, her memory processes were analyzed, using the same picture priming task, carried twelve times during the period of seven months. We used semantic priming paradigm. Three types of prime-target pair were used: identical, semantically related and unrelated. After a prime picture, a target picture appeared on the CRT display. She was asked to name each target as rapidly and accurately as possible. We analysed reaction time (RT) in naming the picture targets, error rate, and verbal reports of the priming task in the pre- and post-examination interview. In the first examination, priming effect was observed in her RT as in the controls'. This suggests that she retained some amount of semantic memory, and the structure of her semantic memory closely resembled that in the controls. Naming RT reduced and error rate decreased with repetition of the examination. This suggests that she acquired picture naming skill during early few examinations. However it was difficult for her to recognize and recollect the picture stimuli in this period. Further, she did not show any episodic memory of the examinations. There was dissociation between improved RT performance and poor verbal reports during early few examinations. When the same priming task was repeated in early few examinations, the priming effect became weaker in her RT. In the controls, on the contrary, the priming effect remained during the whole task repetition. Semantic strategy was apparently used in the controls, but not in the amnesic patient. She apparently used strategy of non-semantic association between the prime and target. In the last few examinations, her naming RT delayed and the priming effect was observed again as in the first examination. She seemed to use semantic strategy. In addition to this priming effect, she re-collected a few pictures and showed some episodic memory of the examination.(ABSTRACT TRUNCATED AT 400 WORDS)

Improving prospective memory performance with future event simulation in traumatic brain injury patients.

PubMed

Mioni, Giovanna; Bertucci, Erica; Rosato, Antonella; Terrett, Gill; Rendell, Peter G; Zamuner, Massimo; Stablum, Franca

2017-06-01

Previous studies have shown that traumatic brain injury (TBI) patients have difficulties with prospective memory (PM). Considering that PM is closely linked to independent living it is of primary interest to develop strategies that can improve PM performance in TBI patients. This study employed Virtual Week task as a measure of PM, and we included future event simulation to boost PM performance. Study 1 evaluated the efficacy of the strategy and investigated possible practice effects. Twenty-four healthy participants performed Virtual Week in a no strategy condition, and 24 healthy participants performed it in a mixed condition (no strategy - future event simulation). In Study 2, 18 TBI patients completed the mixed condition of Virtual Week and were compared with the 24 healthy controls who undertook the mixed condition of Virtual Week in Study 1. All participants also completed a neuropsychological evaluation to characterize the groups on level of cognitive functioning. Study 1 showed that participants in the future event simulation condition outperformed participants in the no strategy condition, and these results were not attributable to practice effects. Results of Study 2 showed that TBI patients performed PM tasks less accurately than controls, but that future event simulation can substantially reduce TBI-related deficits in PM performance. The future event simulation strategy also improved the controls' PM performance. These studies showed the value of future event simulation strategy in improving PM performance in healthy participants as well as in TBI patients. TBI patients performed PM tasks less accurately than controls, confirming prospective memory impairment in these patients. Participants in the future event simulation condition out-performed participants in the no strategy condition. Future event simulation can substantially reduce TBI-related deficits in PM performance. Future event simulation strategy also improved the controls' PM performance. © 2017 The British Psychological Society.

Memory Support Strategies and Bundles: A Pathway to Improving Cognitive Therapy for Depression?

PubMed Central

Dong, Lu; Lee, Jason Y.; Harvey, Allison G.

2017-01-01

Objective Therapist use of memory support (MS) alongside treatment-as-usual, with the goal of enhancing patient recall of treatment contents, has been of recent interest as a novel pathway to improve treatment outcome. The Memory Support Intervention involves treatment providers’ using eight specific MS strategies to promote patient memory for treatment. The present study examines to what extent therapist use of MS strategies and bundles improves patient recall of treatment contents and treatment outcome. Methods The data were drawn from a pilot randomized controlled trial reported elsewhere. Participants were 48 adults (mean age = 44.27 years, 29 females) with major depressive disorder (MDD), randomized to receive 14 sessions of either CT+Memory Support (n = 25) or CT-as-usual (n = 23). Therapist use of MS was coded using the Memory Support Rating Scale. Patient memory and treatment outcomes were assessed at baseline, mid-treatment (patient recall only), post-treatment, and 6-month follow-up. Results Participants in CT+Memory Support received significantly higher amount of MS relative to CT-as-usual. Though not reaching statistical significance, small-to-medium effects were observed between MS strategies and patient recall in the expected direction. Although MS variables were not significantly associated with changes in continuous depressive symptoms, MS was associated with better global functioning. MS also exhibited small to medium effects on treatment response and recurrence in the expected direction but not on remission, though these effects did not reach statistical significance. Conclusions These results provide initial empirical evidence supporting an active method for therapists to implement MS strategies. PMID:28221056

Self-imagining enhances recognition memory in memory-impaired individuals with neurological damage.

PubMed

Grilli, Matthew D; Glisky, Elizabeth L

2010-11-01

The ability to imagine an elaborative event from a personal perspective relies on several cognitive processes that may potentially enhance subsequent memory for the event, including visual imagery, semantic elaboration, emotional processing, and self-referential processing. In an effort to find a novel strategy for enhancing memory in memory-impaired individuals with neurological damage, we investigated the mnemonic benefit of a method we refer to as self-imagining-the imagining of an event from a realistic, personal perspective. Fourteen individuals with neurologically based memory deficits and 14 healthy control participants intentionally encoded neutral and emotional sentences under three instructions: structural-baseline processing, semantic processing, and self-imagining. Findings revealed a robust "self-imagination effect (SIE)," as self-imagination enhanced recognition memory relative to deep semantic elaboration in both memory-impaired individuals, F(1, 13) = 32.11, p < .001, η2 = .71; and healthy controls, F(1, 13) = 5.57, p < .05, η2 = .30. In addition, results indicated that mnemonic benefits of self-imagination were not limited by severity of the memory disorder nor were they related to self-reported vividness of visual imagery, semantic processing, or emotional content of the materials. The findings suggest that the SIE may depend on unique mnemonic mechanisms possibly related to self-referential processing and that imagining an event from a personal perspective makes that event particularly memorable even for those individuals with severe memory deficits. Self-imagining may thus provide an effective rehabilitation strategy for individuals with memory impairment.

Facilitating change in health-related behaviors and intentions: a randomized controlled trial of a multidimensional memory program for older adults.

PubMed

Wiegand, Melanie A; Troyer, Angela K; Gojmerac, Christina; Murphy, Kelly J

2013-01-01

Many older adults are concerned about memory changes with age and consequently seek ways to optimize their memory function. Memory programs are known to be variably effective in improving memory knowledge, other aspects of metamemory, and/or objective memory, but little is known about their impact on implementing and sustaining lifestyle and healthcare-seeking intentions and behaviors. We evaluated a multidimensional, evidence-based intervention, the Memory and Aging Program, that provides education about memory and memory change, training in the use of practical memory strategies, and support for implementation of healthy lifestyle behavior changes. In a randomized controlled trial, 42 healthy older adults participated in a program (n = 21) or a waitlist control (n = 21) group. Relative to the control group, participants in the program implemented more healthy lifestyle behaviors by the end of the program and maintained these changes 1 month later. Similarly, program participants reported a decreased intention to seek unnecessary medical attention for their memory immediately after the program and 1 month later. Findings support the use of multidimensional memory programs to promote healthy lifestyles and influence healthcare-seeking behaviors. Discussion focuses on implications of these changes for maximizing cognitive health and minimizing impact on healthcare resources.

Age-related impairments in active learning and strategic visual exploration.

PubMed

Brandstatt, Kelly L; Voss, Joel L

2014-01-01

Old age could impair memory by disrupting learning strategies used by younger individuals. We tested this possibility by manipulating the ability to use visual-exploration strategies during learning. Subjects controlled visual exploration during active learning, thus permitting the use of strategies, whereas strategies were limited during passive learning via predetermined exploration patterns. Performance on tests of object recognition and object-location recall was matched for younger and older subjects for objects studied passively, when learning strategies were restricted. Active learning improved object recognition similarly for younger and older subjects. However, active learning improved object-location recall for younger subjects, but not older subjects. Exploration patterns were used to identify a learning strategy involving repeat viewing. Older subjects used this strategy less frequently and it provided less memory benefit compared to younger subjects. In previous experiments, we linked hippocampal-prefrontal co-activation to improvements in object-location recall from active learning and to the exploration strategy. Collectively, these findings suggest that age-related memory problems result partly from impaired strategies during learning, potentially due to reduced hippocampal-prefrontal co-engagement.

Cognitive Strategies, Working Memory, and Growth in Word Problem Solving in Children With Math Difficulties.

PubMed

Swanson, H Lee; Lussier, Catherine M; Orosco, Michael J

2015-01-01

This study investigated the role of strategy instruction and working memory capacity (WMC) on word problem solving accuracy in children with (n = 100) and without (n = 92) math difficulties (MD). Within classrooms, children in Grades 2 and 3 were randomly assigned to one of four treatment conditions: verbal-only strategies (e.g., underlining question sentence), verbal + visual strategies, visual-only strategies (e.g., correctly placing numbers in diagrams), or untreated control. Strategy interventions included 20 sessions in both Year 1 and Year 2. The intent-to-treat as well as the "as-treated" analyses showed that treatment effects were significantly moderated by WMC. In general, treatment outcomes were higher when WMC was set to a high rather than low level. When set to a relatively high WMC level, children with MD performed significantly better under visual-only strategy conditions and children without MD performed better under verbal + visual conditions when compared to control conditions. © Hammill Institute on Disabilities 2013.

A Randomized Control Trial of Working Memory Training With and Without Strategy Instruction: Effects on Young Children’s Working Memory and Comprehension

PubMed Central

Peng, Peng

2015-01-01

Researchers are increasingly interested in working memory (WM) training. However, it is unclear whether it strengthens comprehension in young children who are at risk for learning difficulties. We conducted a modest study of whether the training of verbal WM would improve verbal WM and passage listening comprehension, and whether training effects differed between two approaches: training with and without strategy instruction. A total of 58 first-grade children were randomly assigned to 3 groups: WM training with a rehearsal strategy, WM training without strategy instruction, and controls. Every member of the 2 training groups received a one-to-one, 35-minute session of verbal WM training on each of 10 consecutive school days, totaling 5.8 hours. Both training groups improved on trained verbal WM tasks, with the rehearsal group making greater gains. Without correction for multiple group comparisons, the rehearsal group made reliable improvements over controls on an untrained verbal WM task and on passage listening comprehension and listening retell measures. The no-strategy- instruction group outperformed controls on passage listening comprehension. When corrected for multiple contrasts, these group differences disappeared, but were associated with moderate-to-large effect sizes. Findings suggest—however tentatively—that brief but intensive verbal WM training may strengthen the verbal WM and comprehension performance of young children at risk. Necessary caveats and possible implications for theory and future research are discussed. PMID:26156961

A Randomized Control Trial of Working Memory Training With and Without Strategy Instruction: Effects on Young Children's Working Memory and Comprehension.

PubMed

Peng, Peng; Fuchs, Douglas

2017-01-01

Researchers are increasingly interested in working memory (WM) training. However, it is unclear whether it strengthens comprehension in young children who are at risk for learning difficulties. We conducted a modest study of whether the training of verbal WM would improve verbal WM and passage listening comprehension and whether training effects differed between two approaches: training with and without strategy instruction. A total of 58 first-grade children were randomly assigned to three groups: WM training with a rehearsal strategy, WM training without strategy instruction, and controls. Each member of the two training groups received a one-to-one, 35-min session of verbal WM training on each of 10 consecutive school days, totaling 5.8 hr. Both training groups improved on trained verbal WM tasks, with the rehearsal group making greater gains. Without correction for multiple group comparisons, the rehearsal group made reliable improvements over controls on an untrained verbal WM task and on passage listening comprehension and listening retell measures. The no-strategy-instruction group outperformed controls on passage listening comprehension. When corrected for multiple contrasts, these group differences disappeared but were associated with moderate to large effect sizes. Findings suggest-however tentatively-that brief but intensive verbal WM training may strengthen the verbal WM and comprehension performance of young children at risk. Necessary caveats and possible implications for theory and future research are discussed. © Hammill Institute on Disabilities 2015.

Intelligence rules of hysteresis in the feedforward trajectory control of piezoelectrically-driven nanostagers

NASA Astrophysics Data System (ADS)

Bashash, Saeid; Jalili, Nader

2007-02-01

Piezoelectrically-driven nanostagers have limited performance in a variety of feedforward and feedback positioning applications because of their nonlinear hysteretic response to input voltage. The hysteresis phenomenon is well known for its complex and multi-path behavior. To realize the underlying physics of this phenomenon and to develop an efficient compensation strategy, the intelligence properties of hysteresis with the effects of non-local memories are discussed here. Through performing a set of experiments on a piezoelectrically-driven nanostager with a high resolution capacitive position sensor, it is shown that for the precise prediction of the hysteresis path, certain memory units are required to store the previous hysteresis trajectory data. Based on the experimental observations, a constitutive memory-based mathematical modeling framework is developed and trained for the precise prediction of the hysteresis path for arbitrarily assigned input profiles. Using the inverse hysteresis model, a feedforward control strategy is then developed and implemented on the nanostager to compensate for the ever-present nonlinearity. Experimental results demonstrate that the controller remarkably eliminates the nonlinear effect, if memory units are sufficiently chosen for the inverse model.

Contribution of Regional White Matter Integrity to Visuospatial Construction Accuracy, Organizational Strategy, and Memory for a Complex Figure in Abstinent Alcoholics.

PubMed

Rosenbloom, Margaret J; Sassoon, Stephanie A; Pfefferbaum, Adolf; Sullivan, Edith V

2009-12-01

Visuospatial construction ability as used in drawing complex figures is commonly impaired in chronic alcoholics, but memory for such information can be enhanced by use of a holistic drawing strategy during encoding. We administered the Rey-Osterrieth Complex Figure Test (ROCFT) to 41 alcoholic and 38 control men and women and assessed the contribution of diffusion tensor imaging (DTI) measures of integrity of selected white matter tracts to ROCFT copy accuracy, copy strategy, and recall accuracy. Although alcoholics copied the figure less accurately than controls, a more holistic strategy at copy was associated with better recall in both groups. Greater radial diffusivity, reflecting compromised myelin integrity, in occipital forceps and external capsule was associated with poorer copy accuracy in both groups. Lower FA, reflecting compromised fiber microstructure in the inferior cingulate bundle, which links frontal and medial temporal episodic memory systems, was associated with piecemeal copy strategy and poorer immediate recall in the alcoholics. The correlations were generally modest and should be considered exploratory. To the extent that the inferior cingulate was relatively spared in alcoholics, it may have provided an alternative pathway to the compromised frontal system for successful copy strategy and, by extension, aided recall.

Practice makes imperfect: Working memory training can harm recognition memory performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matzen, Laura E.; Trumbo, Michael C.; Haass, Michael J.

There is a great deal of debate concerning the benefits of working memory (WM) training and whether that training can transfer to other tasks. Although a consistent finding is that WM training programs elicit a short-term near-transfer effect (i.e., improvement in WM skills), results are inconsistent when considering persistence of such improvement and far transfer effects. In this study, we compared three groups of participants: a group that received WM training, a group that received training on how to use a mental imagery memory strategy, and a control group that received no training. Although the WM training group improved onmore » the trained task, their posttraining performance on nontrained WM tasks did not differ from that of the other two groups. In addition, although the imagery training group’s performance on a recognition memory task increased after training, the WM training group’s performance on the task decreased after training. Participants’ descriptions of the strategies they used to remember the studied items indicated that WM training may lead people to adopt memory strategies that are less effective for other types of memory tasks. Our results indicate that WM training may have unintended consequences for other types of memory performance.« less

Affect influences false memories at encoding: evidence from recognition data.

PubMed

Storbeck, Justin; Clore, Gerald L

2011-08-01

Memory is susceptible to illusions in the form of false memories. Prior research found, however, that sad moods reduce false memories. The current experiment had two goals: (1) to determine whether affect influences retrieval processes, and (2) to determine whether affect influences the strength and the persistence of false memories. Happy or sad moods were induced either before or after learning word lists designed to produce false memories. Control groups did not experience a mood induction. We found that sad moods reduced false memories only when induced before learning. Signal detection analyses confirmed that sad moods induced prior to learning reduced activation of nonpresented critical lures suggesting that they came to mind less often. Affective states, however, did not influence retrieval effects. We conclude that negative affective states promote item-specific processing, which reduces false memories in a similar way as using an explicitly guided cognitive control strategy. 2011 APA, all rights reserved

Affect Influences False Memories at Encoding: Evidence from Recognition Data

PubMed Central

Storbeck, Justin; Clore, Gerald L.

2014-01-01

Memory is susceptible to illusions in the form of false memories. Prior research found, however, that sad moods reduce false memories. The current experiment had two goals: (1) to determine whether affect influences retrieval processes, and (2) to determine whether affect influences the strength and the persistence of false memories. Happy or sad moods were induced either before or after learning word lists designed to produce false memories. Control groups did not experience a mood induction. We found that sad moods reduced false memories only when induced before learning. Signal detection analyses confirmed that sad moods induced prior to learning reduced activation of nonpresented critical lures suggesting that they came to mind less often. Affective states, however, did not influence retrieval effects. We conclude that negative affective states promote item-specific processing, which reduces false memories in a similar way as using an explicitly guided cognitive control strategy. PMID:21517165

Free Recall of Word Lists under Total Sleep Deprivation and after Recovery Sleep

PubMed Central

de Almeida Valverde Zanini, Gislaine; Tufik, Sérgio; Andersen, Monica Levy; da Silva, Raquel Cristina Martins; Bueno, Orlando Francisco Amodeo; Rodrigues, Camila Cruz; Pompéia, Sabine

2012-01-01

Study Objectives: One task that has been used to assess memory effects of prior total sleep deprivation (TSD) is the immediate free recall of word lists; however, results have been mixed. A possible explanation for this is task impurity, since recall of words from different serial positions reflects use of distinct types of memory (last words: short-term memory; first and intermediate words: episodic memory). Here we studied the effects of 2 nights of TSD on immediate free recall of semantically unrelated word lists considering the serial position curve. Design: Random allocation to a 2-night TSD protocol followed by one night of recovery sleep or to a control group. Setting: Study conducted under continuous behavioral monitoring. Participants: 24 young, healthy male volunteers. Intervention: 2 nights of total sleep deprivation (TSD) and one night of recovery sleep. Measurements and Results: Participants were shown five 15 unrelated word-lists at baseline, after one and 2 nights of TSD, and after one night of recovery sleep. We also investigated the development of recall strategies (learning) and susceptibility to interference from previous lists. No free recall impairment occurred during TSD, irrespective of serial position. Interference was unchanged. Both groups developed recall strategies, but task learning occurred earlier in controls and was evident in the TSD group only after sleep recovery. Conclusion: Prior TSD spared episodic memory, short-term phonological memory, and interference, allowed the development of recall strategies, but may have decreased the advantage of using these strategies, which returned to normal after recovery sleep. Citation: Zanini GAV; Tufik S; Andersen ML; da Silva RCM; Bueno OFA; Rodrigues CC; Pompéia S. Free recall of word lists under total sleep deprivation and after recovery sleep. SLEEP 2012;35(2):223-230. PMID:22294812

Right inferior frontal gyrus activation is associated with memory improvement in patients with left frontal low-grade glioma resection.

PubMed

Miotto, Eliane C; Balardin, Joana B; Vieira, Gilson; Sato, Joao R; Martin, Maria da Graça M; Scaff, Milberto; Teixeira, Manoel J; Junior, Edson Amaro

2014-01-01

Patients with low-grade glioma (LGG) have been studied as a model of functional brain reorganization due to their slow-growing nature. However, there is no information regarding which brain areas are involved during verbal memory encoding after extensive left frontal LGG resection. In addition, it remains unknown whether these patients can improve their memory performance after instructions to apply efficient strategies. The neural correlates of verbal memory encoding were investigated in patients who had undergone extensive left frontal lobe (LFL) LGG resections and healthy controls using fMRI both before and after directed instructions were given for semantic organizational strategies. Participants were scanned during the encoding of word lists under three different conditions before and after a brief period of practice. The conditions included semantically unrelated (UR), related-non-structured (RNS), and related-structured words (RS), allowing for different levels of semantic organization. All participants improved on memory recall and semantic strategy application after the instructions for the RNS condition. Healthy subjects showed increased activation in the left inferior frontal gyrus (IFG) and middle frontal gyrus (MFG) during encoding for the RNS condition after the instructions. Patients with LFL excisions demonstrated increased activation in the right IFG for the RNS condition after instructions were given for the semantic strategies. Despite extensive damage in relevant areas that support verbal memory encoding and semantic strategy applications, patients that had undergone resections for LFL tumor could recruit the right-sided contralateral homologous areas after instructions were given and semantic strategies were practiced. These results provide insights into changes in brain activation areas typically implicated in verbal memory encoding and semantic processing.

Influence of personality and neuropsychological ability on social functioning and self-management in bipolar disorder.

PubMed

Vierck, Esther; Joyce, Peter R

2015-10-30

A majority of bipolar patients (BD) show functional difficulties even in remission. In recent years cognitive functions and personality characteristics have been associated with occupational and psychosocial outcomes, but findings are not consistent. We assessed personality and cognitive functioning through a range of tests in BD and control participants. Three cognitive domains-verbal memory, facial-executive, and spatial memory-were extracted by principal component analysis. These factors and selected personality dimensions were included in hierarchical regression analysis to predict psychosocial functioning and the use of self-management strategies while controlling for mood status. The best determinants of good psychosocial functioning were good verbal memory and high self-directedness. The use of self-management techniques was associated with a low level of harm-avoidance. Our findings indicate that strategies to improve memory and self-directedness may be useful for increasing functioning in individuals with bipolar disorder. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The efficacy of a multifactorial memory training in older adults living in residential care settings.

PubMed

Vranić, Andrea; Španić, Ana Marija; Carretti, Barbara; Borella, Erika

2013-11-01

Several studies have shown an increase in memory performance after teaching mnemonic techniques to older participants. However, transfer effects to non-trained tasks are generally either very small, or not found. The present study investigates the efficacy of a multifactorial memory training program for older adults living in a residential care center. The program combines teaching of memory strategies with activities based on metacognitive (metamemory) and motivational aspects. Specific training-related gains in the Immediate list recall task (criterion task), as well as transfer effects on measures of short-term memory, long-term memory, working memory, motivational (need for cognition), and metacognitive aspects (subjective measure of one's memory) were examined. Maintenance of training benefits was assessed after seven months. Fifty-one older adults living in a residential care center, with no cognitive impairments, participated in the study. Participants were randomly assigned to two programs: the experimental group attended the training program, while the active control group was involved in a program in which different psychological issues were discussed. A benefit in the criterion task and substantial general transfer effects were found for the trained group, but not for the active control, and they were maintained at the seven months follow-up. Our results suggest that training procedures, which combine teaching of strategies with metacognitive-motivational aspects, can improve cognitive functioning and attitude toward cognitive activities in older adults.

Self-Imagining Enhances Recognition Memory in Memory-Impaired Individuals with Neurological Damage

PubMed Central

Grilli, Matthew D.; Glisky, Elizabeth L.

2010-01-01

Objective The ability to imagine an elaborative event from a personal perspective relies on a number of cognitive processes that may potentially enhance subsequent memory for the event, including visual imagery, semantic elaboration, emotional processing, and self-referential processing. In an effort to find a novel strategy for enhancing memory in memory-impaired individuals with neurological damage, the present study investigated the mnemonic benefit of a method we refer to as “self-imagining” – or the imagining of an event from a realistic, personal perspective. Method Fourteen individuals with neurologically-based memory deficits and fourteen healthy control participants intentionally encoded neutral and emotional sentences under three instructions: structural-baseline processing, semantic processing, and self-imagining. Results Findings revealed a robust “self-imagination effect” as self-imagination enhanced recognition memory relative to deep semantic elaboration in both memory-impaired individuals, F (1, 13) = 32.11, p < .001, η2 = .71, and healthy controls, F (1, 13) = 5.57, p < .05, η2 = .30. In addition, results indicated that mnemonic benefits of self-imagination were not limited by severity of the memory disorder nor were they related to self-reported vividness of visual imagery, semantic processing, or emotional content of the materials. Conclusions The findings suggest that the self-imagination effect may depend on unique mnemonic mechanisms possibly related to self-referential processing, and that imagining an event from a personal perspective makes that event particularly memorable even for those individuals with severe memory deficits. Self-imagining may thus provide an effective rehabilitation strategy for individuals with memory impairment. PMID:20873930

A Randomized Control Trial of Working Memory Training with and without Strategy Instruction: Effects on Young Children's Working Memory and Comprehension

ERIC Educational Resources Information Center

Peng, Peng; Fuchs, Douglas

2017-01-01

Researchers are increasingly interested in working memory (WM) training. However, it is unclear whether it strengthens comprehension in young children who are at risk for learning difficulties. We conducted a modest study of whether the training of verbal WM would improve verbal WM and passage listening comprehension and whether training effects…

The use of metacognitive strategies to decrease false memories in source monitoring in patients with mild cognitive impairment.

PubMed

Deason, Rebecca G; Nadkarni, Neil A; Tat, Michelle J; Flannery, Sean; Frustace, Bruno; Ally, Brandon A; Budson, Andrew E

2017-06-01

Patients with amnestic mild cognitive impairment (MCI) and Alzheimer's disease (AD) often demonstrate high rates of false memories, leading to stressful and frustrating situations for both patients and caregivers in everyday life. Sometimes these false memories are due to failures in monitoring the source of the information. In the current study, we examined interventions aimed to enhance the use of the metacognitive "recall-to-reject" memory strategy. Such interventions could improve source memory and decrease false memory in patients with MCI. Because the picture superiority effect (better memory for pictures compared to words) has been shown to be present in both patients with MCI and healthy older controls, we investigated whether pictures could help patients with MCI use a recall-to-reject strategy in a simulation of real-world source memory task. In this experiment, patients with MCI and healthy older adults were asked to simulate preparing for and then taking a trip to the market. Subjects first studied 30 pictures of items in their "cupboard," followed by a list of 30 words of items on their "shopping list." At test, participants saw 90 pictures (30 cupboard, 30 list, 30 new) organized as they would be if walking down the market aisles, and are provided with either standard or metacognitive instructions. With standard instructions, they were asked if they needed to buy the item. With the metacognitive instructions, they were asked a series of questions to help guide them through a recall-to-reject strategy to highlight the different sources of memories. Results showed that the metacognitive instructions did significantly reduce the false memory rates for patients with MCI. Further studies need to investigate how to best implement these practical strategies into the everyday lives of patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Episodic memory and organizational strategy in free recall in unipolar depression: the role of cognitive support and executive functions.

PubMed

Taconnat, Laurence; Baudouin, Alexia; Fay, Severine; Raz, Naftali; Bouazzaoui, Badiaa; El-Hage, Wissam; Isingrini, Michel; Ergis, Anne-Marie

2010-08-01

Executive functioning and memory impairment have been demonstrated in adults with depression. Executive functions and memory are related, mainly when the memory tasks require controlled processes (attentional resource demanding processes)--that is, when a low cognitive support (external aid) is provided. A cross-sectional study was carried out on 45 participants: 21 with depression, and 24 healthy controls matched for age, verbal ability, education level, and anxiety score. Cognitive support was manipulated by providing a categorized word list at encoding, presented either clustered (high cognitive support) or randomized (low cognitive support) to both depressed and healthy adults. The number of words recalled was calculated, and an index of clustering was computed to assess organizational strategies. Participants were also administered cognitive tests (executive functions, cognitive speed, and categorical fluency) to explore the mediators of organizational strategies. Depressed participants had greater difficulty recalling and organizing the words, but the differences between the two groups were reduced for both measures when high cognitive support was provided at encoding. Healthy adults performed better on all cognitive tests. Statistical analyses revealed that in the depressed group, executive functions were the only variable associated with clustering and only when low cognitive support was provided. These findings support the view that the decrement in executive function due to depression may lead to impairment in organization when this mnemonic strategy has to be self-initiated.

ADHD and math - The differential effect on calculation and estimation.

PubMed

Ganor-Stern, Dana; Steinhorn, Ofir

2018-05-31

Adults with ADHD were compared to controls when solving multiplication problems exactly and when estimating the results of multidigit multiplication problems relative to reference numbers. The ADHD participants were slower than controls in the exact calculation and in the estimation tasks, but not less accurate. The ADHD participants were similar to controls in showing enhanced accuracy and speed for smaller problem sizes, for trials in which the reference numbers were smaller (vs. larger) than the exact answers and for reference numbers that were far (vs. close) from the exact answer. The two groups similarly used the approximated calculation and the sense of magnitude strategies. They differed however in strategy execution, mainly of the approximated calculation strategy, which requires working memory resources. The increase in reaction time associated with using the approximated calculation strategy was larger for the ADHD compared to the control participants. Thus, ADHD seems to selectively impair calculation processes in estimation tasks that rely on working memory, but it does not hamper estimation skills that are based on sense of magnitude. The educational implications of these findings are discussed. Copyright © 2018. Published by Elsevier B.V.

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.

Spatial memory tasks in rodents: what do they model?

PubMed

Morellini, Fabio

2013-10-01

The analysis of spatial learning and memory in rodents is commonly used to investigate the mechanisms underlying certain forms of human cognition and to model their dysfunction in neuropsychiatric and neurodegenerative diseases. Proper interpretation of rodent behavior in terms of spatial memory and as a model of human cognitive functions is only possible if various navigation strategies and factors controlling the performance of the animal in a spatial task are taken into consideration. The aim of this review is to describe the experimental approaches that are being used for the study of spatial memory in rats and mice and the way that they can be interpreted in terms of general memory functions. After an introduction to the classification of memory into various categories and respective underlying neuroanatomical substrates, I explain the concept of spatial memory and its measurement in rats and mice by analysis of their navigation strategies. Subsequently, I describe the most common paradigms for spatial memory assessment with specific focus on methodological issues relevant for the correct interpretation of the results in terms of cognitive function. Finally, I present recent advances in the use of spatial memory tasks to investigate episodic-like memory in mice.

Age differences in perceptions of memory strategy effectiveness for recent and remote memory.

PubMed

Lineweaver, Tara T; Horhota, Michelle; Crumley, Jessica; Geanon, Catherine T; Juett, Jacqueline J

2018-03-01

We examined whether young and older adults hold different beliefs about the effectiveness of memory strategies for specific types of memory tasks and whether memory strategies are perceived to be differentially effective for young, middle-aged, and older targets. Participants rated the effectiveness of five memory strategies for 10 memory tasks at three target ages (20, 50, and 80 years old). Older adults did not strongly differentiate strategy effectiveness, viewing most strategies as similarly effective across memory tasks. Young adults held strategy-specific beliefs, endorsing external aids and physical health as more effective than a positive attitude or internal strategies, without substantial differentiation based on task. We also found differences in anticipated strategy effectiveness for targets of different ages. Older adults described cognitive and physical health strategies as more effective for older than middle-aged targets, whereas young adults expected these strategies to be equally effective for middle-aged and older target adults.

Hippocampal SSTR4 somatostatin receptors control the selection of memory strategies.

PubMed

Gastambide, François; Viollet, Cécile; Lepousez, Gabriel; Epelbaum, Jacques; Guillou, Jean-Louis

2009-01-01

Somatostatin (SS14) has been implicated in various cognitive disorders, and converging evidence from animal studies suggests that SS14 neurons differentially regulate hippocampal- and striatal-dependent memory formation. Four SS14 receptor subtypes (SSTR1-4) are expressed in the hippocampus, but their respective roles in memory processes remain to be determined. In the present study, effects of selective SSTR1-4 agonists on memory formation were assessed in a water-maze task which can engage either hippocampus-dependent "place" and/or striatum-dependent "cue" memory formation. Mice received an intrahippocampal injection of one of each of the selective agonists and were then trained to locate an escape platform based on either distal cues (place memory) or a visible proximal cue (cue memory). Retention was tested 24 h later on probe trials aimed at identifying which memory strategy was preferentially retained. Both SS14 and the SSTR4 agonist (L-803,087) dramatically impaired place memory formation in a dose-dependent manner, whereas SSTR1 (L-797,591), SSTR2 (L-779,976), or SSTR3 (L-796,778) agonists did not yield any behavioral effects. However, unlike SS14, the SSTR4 agonist also dose-dependently enhanced cue-based memory formation. This effect was confirmed in another striatal-dependent memory task, the bar-pressing task, where L-803,087 improved memory of the instrumental response, whereas SS14 was once again ineffective. These data suggest that hippocampal SSTR4 are selectively involved in the selection of memory strategies by switching from the use of hippocampus-based multiple associations to the use of simple dorsal striatum-based behavioral responses. Possible neural mechanisms and functional implications are discussed.

The Relative Success of a Self-Help and a Group-Based Memory Training Program for Older Adults

PubMed Central

Hastings, Erin C.; West, Robin L.

2011-01-01

This study evaluates self-help and group-based memory training programs to test for their differential impact on memory beliefs and performance. Self-help participants used a manual that presented strategies for name, story, and list recall and practice exercises. Matched content from that same manual was presented by the trainer in 2-hr weekly group sessions for the group-based trainees. Relative to a wait-list control group, most memory measures showed significant gains for both self-help and group-based training, with no significant training condition differences, and these gains were maintained at follow-up. Belief measures showed that locus of control was significantly higher for the self-help and group-based training than the control group; memory self-efficacy significantly declined for controls, increased for group-trained participants, and remained constant in the self-help group. Self-efficacy change in a self-help group may require more opportunities for interacting with peers and/or an instructor emphasizing one's potential for memory change. PMID:19739914

Deficits of organizational strategy and visual memory in obsessive-compulsive disorder.

PubMed

Shin, M S; Park, S J; Kim, M S; Lee, Y H; Ha, T H; Kwon, J S

2004-10-01

This study was conducted to investigate the deficits of organizational strategy and visual memory in obsessive-compulsive disorder (OCD). Thirty OCD patients and 30 healthy controls aged 20-35 years participated. The Maudsley Obsessive-Compulsive Inventory, Beck Anxiety Inventory, Wechsler Adult Intelligence Scale, and Rey-Osterrieth Complex Figure (ROCF) test were administered to participants. The authors scored ROCF performances using the Boston Qualitative Scoring System. The OCD patients showed poorer planning ability and higher fragmentation than did healthy controls when copying the ROCF, and they showed even poorer performances in the immediate and delayed recall conditions. The authors found that the Organization score in the copy condition mediated the difference between the OCD group and the healthy group in immediate recall. The direct effect of diagnosis (OCD or healthy) on the immediate recall condition of the ROCF was also significant. This study indicates that people with OCD have poor memory function and organizational deficits.

Operant conditioning of autobiographical memory retrieval.

PubMed

Debeer, Elise; Raes, Filip; Williams, J Mark G; Craeynest, Miet; Hermans, Dirk

2014-01-01

Functional avoidance is considered as one of the key mechanisms underlying overgeneral autobiographical memory (OGM). According to this view OGM is regarded as a learned cognitive avoidance strategy, based on principles of operant conditioning; i.e., individuals learn to avoid the emotionally painful consequences associated with the retrieval of specific negative memories. The aim of the present study was to test one of the basic assumptions of the functional avoidance account, namely that autobiographical memory retrieval can be brought under operant control. Here 41 students were instructed to retrieve personal memories in response to 60 emotional cue words. Depending on the condition, they were punished with an aversive sound for the retrieval of specific or nonspecific memories in an operant conditioning procedure. Analyzes showed that the course of memory specificity significantly differed between conditions. After the procedure participants punished for nonspecific memories retrieved significantly more specific memories compared to participants punished for specific memories. However, whereas memory specificity significantly increased in participants punished for specific memories, it did not significantly decrease in participants punished for nonspecific memories. Thus, while our findings indicate that autobiographical memory retrieval can be brought under operant control, they do not support a functional avoidance view on OGM.

Memory Functioning in Children and Adolescents With Autism

PubMed Central

Southwick, Jason S.; Bigler, Erin D.; Froehlich, Alyson; DuBray, Molly B.; Alexander, Andrew L.; Lange, Nicholas; Lainhart, Janet E.

2012-01-01

Objective Memory functioning in children and adolescents ages 5–19 with autism (n = 50) and typically developing controls (n = 36) was assessed using a clinical assessment battery, the Test of Memory and Learning (TOMAL). Method Participant groups were statistically comparable in age, nonverbal IQ, handedness, and head circumference, and were administered the TOMAL. Results Test performance on the TOMAL demonstrated broad differences in memory functioning in the autism group, across multiple task formats, including verbal and nonverbal, immediate and delayed, attention and concentration, sequential recall, free recall, associative recall, and multiple-trial learning memory. All index and nearly all subtest differences remained significant even after comparing a subset of the autism group (n = 36) and controls that were matched for verbal IQ ( p >.05). However, retention of previously remembered information after a delay was similar in autism and controls. Conclusions These findings indicate that performance on measures of episodic memory is broadly reduced in autism, and support the conclusion that information encoding and organization, possibly due to inefficient cognitive processing strategies, rather than storage and retrieval, are the primary factors that limit memory performance in autism. PMID:21843004

A Case Study on Neural Inspired Dynamic Memory Management Strategies for High Performance Computing.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vineyard, Craig Michael; Verzi, Stephen Joseph

As high performance computing architectures pursue more computational power there is a need for increased memory capacity and bandwidth as well. A multi-level memory (MLM) architecture addresses this need by combining multiple memory types with different characteristics as varying levels of the same architecture. How to efficiently utilize this memory infrastructure is an unknown challenge, and in this research we sought to investigate whether neural inspired approaches can meaningfully help with memory management. In particular we explored neurogenesis inspired re- source allocation, and were able to show a neural inspired mixed controller policy can beneficially impact how MLM architectures utilizemore » memory.« less

Working Memory in Children With Neurocognitive Effects From Sickle Cell Disease: Contributions of the Central Executive and Processing Speed

PubMed Central

Smith, Kelsey E.; Schatz, Jeffrey

2017-01-01

Children with sickle cell disease (SCD) are at risk for working memory deficits due to multiple disease processes. We assessed working memory abilities and related functions in 32 school-age children with SCD and 85 matched comparison children using Baddeley’s working memory model as a framework. Children with SCD performed worse than controls for working memory, central executive function, and processing/rehearsal speed. Central executive function was found to mediate the relationship between SCD status and working memory, but processing speed did not. Cognitive remediation strategies that focus on central executive processes may be important for remediating working memory deficits in SCD. PMID:27759435

Effect of episodic and working memory impairments on semantic and cognitive procedural learning at alcohol treatment entry.

PubMed

Pitel, Anne Lise; Witkowski, Thomas; Vabret, François; Guillery-Girard, Bérengère; Desgranges, Béatrice; Eustache, Francis; Beaunieux, Hélène

2007-02-01

Chronic alcoholism is known to impair the functioning of episodic and working memory, which may consequently reduce the ability to learn complex novel information. Nevertheless, semantic and cognitive procedural learning have not been properly explored at alcohol treatment entry, despite its potential clinical relevance. The goal of the present study was therefore to determine whether alcoholic patients, immediately after the weaning phase, are cognitively able to acquire complex new knowledge, given their episodic and working memory deficits. Twenty alcoholic inpatients with episodic memory and working memory deficits at alcohol treatment entry and a control group of 20 healthy subjects underwent a protocol of semantic acquisition and cognitive procedural learning. The semantic learning task consisted of the acquisition of 10 novel concepts, while subjects were administered the Tower of Toronto task to measure cognitive procedural learning. Analyses showed that although alcoholic subjects were able to acquire the category and features of the semantic concepts, albeit slowly, they presented impaired label learning. In the control group, executive functions and episodic memory predicted semantic learning in the first and second halves of the protocol, respectively. In addition to the cognitive processes involved in the learning strategies invoked by controls, alcoholic subjects seem to attempt to compensate for their impaired cognitive functions, invoking capacities of short-term passive storage. Regarding cognitive procedural learning, although the patients eventually achieved the same results as the controls, they failed to automate the procedure. Contrary to the control group, the alcoholic groups' learning performance was predicted by controlled cognitive functions throughout the protocol. At alcohol treatment entry, alcoholic patients with neuropsychological deficits have difficulty acquiring novel semantic and cognitive procedural knowledge. Compared with controls, they seem to use more costly learning strategies, which are nonetheless less efficient. These learning disabilities need to be considered when treatment requiring the acquisition of complex novel information is envisaged.

Verbal and Visual Memory Impairments in Bipolar I and II Disorder.

PubMed

Ha, Tae Hyon; Kim, Ji Sun; Chang, Jae Seung; Oh, Sung Hee; Her, Ju Young; Cho, Hyun Sang; Park, Tae Sung; Shin, Soon Young; Ha, Kyooseob

2012-12-01

To compare verbal and visual memory performances between patients with bipolar I disorder (BD I) and patients with bipolar II disorder (BD II) and to determine whether memory deficits were mediated by impaired organizational strategies. Performances on the Korean-California Verbal Learning Test (K-CVLT) and the Rey-Osterrieth Complex Figure Test (ROCF) in 37 patients with BD I, 46 patients with BD II and 42 healthy subjects were compared. Mediating effects of impaired organization strategies on poor delayed recall was tested by comparing direct and mediated models using multiple regression analysis. Both patients groups recalled fewer words and figure components and showed lower Semantic Clustering compared to controls. Verbal memory impairment was partly mediated by difficulties in Semantic Clustering in both subtypes, whereas the mediating effect of Organization deficit on the visual memory impairment was present only in BD I. In all mediated models, group differences in delayed recall remained significant. Our findings suggest that memory impairment may be one of the fundamental cognitive deficits in bipolar disorders and that executive dysfunctions can exert an additional influence on memory impairments.

A comparison of self-generated versus taught internal strategies for working memory.

PubMed

Dirette, Diane Powers

2015-01-01

Internal strategies are effective for improving working memory. These internal working memory strategies can be taught or self-generated. This study compares working memory performance using taught versus self-generated internal working memory strategies and explores the quantity, type and carry-over of the use of these strategies. An experimental cohort design with randomly assigned groups compared the performances among 120 participants on 5 memory tests given prior, immediately following and at 1 month post intervention. There were no significant differences in the number or type of internal memory strategies used by the groups with chunking, repetition and association used most commonly. The group that self-generated strategies performed significantly better on a contextual memory test and the group that was taught strategies performed better on a face/name recall test for which a specific strategy was taught. The group that was taught strategies performed significantly worse on contextual memory tests from pre-test to follow-up. Participants who generated their own strategies or used a specific strategy for a specific task did as well as participants who were taught myriad internal WM strategies. Teaching too many strategies may overwhelm participants or may distract them from using the context that is available in such tasks.

Choline acetyltransferase in the hippocampus is associated with learning strategy preference in adult male rats.

PubMed

Hawley, Wayne R; Witty, Christine F; Daniel, Jill M; Dohanich, Gary P

2015-08-01

One principle of the multiple memory systems hypothesis posits that the hippocampus-based and striatum-based memory systems compete for control over learning. Consistent with this notion, previous research indicates that the cholinergic system of the hippocampus plays a role in modulating the preference for a hippocampus-based place learning strategy over a striatum-based stimulus--response learning strategy. Interestingly, in the hippocampus, greater activity and higher protein levels of choline acetyltransferase (ChAT), the enzyme that synthesizes acetylcholine, are associated with better performance on hippocampus-based learning and memory tasks. With this in mind, the primary aim of the current study was to determine if higher levels of ChAT and the high-affinity choline uptake transporter (CHT) in the hippocampus were associated with a preference for a hippocampus-based place learning strategy on a task that also could be solved by relying on a striatum-based stimulus--response learning strategy. Results confirmed that levels of ChAT in the dorsal region of the hippocampus were associated with a preference for a place learning strategy on a water maze task that could also be solved by adopting a stimulus-response learning strategy. Consistent with previous studies, the current results support the hypothesis that the cholinergic system of the hippocampus plays a role in balancing competition between memory systems that modulate learning strategy preference. Copyright © 2015 Elsevier B.V. All rights reserved.

Using Maintenance Rehearsal to Explore Recognition Memory

ERIC Educational Resources Information Center

Humphreys, Michael S.; Maguire, Angela M.; McFarlane, Kimberley A.; Burt, Jennifer S.; Bolland, Scott W.; Murray, Krista L.; Dunn, Ryan

2010-01-01

We examined associative and item recognition using the maintenance rehearsal paradigm. Our intent was to control for mnemonic strategies; to produce a low, graded level of learning; and to provide evidence of the role of attention in long-term memory. An advantage for low-frequency words emerged in both associative and item recognition at very low…

Validity of the MicroDYN Approach: Complex Problem Solving Predicts School Grades beyond Working Memory Capacity

ERIC Educational Resources Information Center

Schweizer, Fabian; Wustenberg, Sascha; Greiff, Samuel

2013-01-01

This study examines the validity of the complex problem solving (CPS) test MicroDYN by investigating a) the relation between its dimensions--rule identification (exploration strategy), rule knowledge (acquired knowledge), rule application (control performance)--and working memory capacity (WMC), and b) whether CPS predicts school grades in…

INDIRECT INTELLIGENT SLIDING MODE CONTROL OF A SHAPE MEMORY ALLOY ACTUATED FLEXIBLE BEAM USING HYSTERETIC RECURRENT NEURAL NETWORKS.

PubMed

Hannen, Jennifer C; Crews, John H; Buckner, Gregory D

2012-08-01

This paper introduces an indirect intelligent sliding mode controller (IISMC) for shape memory alloy (SMA) actuators, specifically a flexible beam deflected by a single offset SMA tendon. The controller manipulates applied voltage, which alters SMA tendon temperature to track reference bending angles. A hysteretic recurrent neural network (HRNN) captures the nonlinear, hysteretic relationship between SMA temperature and bending angle. The variable structure control strategy provides robustness to model uncertainties and parameter variations, while effectively compensating for system nonlinearities, achieving superior tracking compared to an optimized PI controller.

The development of strategy use in elementary school children: working memory and individual differences.

PubMed

Imbo, Ineke; Vandierendonck, André

2007-04-01

The current study tested the development of working memory involvement in children's arithmetic strategy selection and strategy efficiency. To this end, an experiment in which the dual-task method and the choice/no-choice method were combined was administered to 10- to 12-year-olds. Working memory was needed in retrieval, transformation, and counting strategies, but the ratio between available working memory resources and arithmetic task demands changed across development. More frequent retrieval use, more efficient memory retrieval, and more efficient counting processes reduced the working memory requirements. Strategy efficiency and strategy selection were also modified by individual differences such as processing speed, arithmetic skill, gender, and math anxiety. Short-term memory capacity, in contrast, was not related to children's strategy selection or strategy efficiency.

Free recall test experience potentiates strategy-driven effects of value on memory.

PubMed

Cohen, Michael S; Rissman, Jesse; Hovhannisyan, Mariam; Castel, Alan D; Knowlton, Barbara J

2017-10-01

People tend to show better memory for information that is deemed valuable or important. By one mechanism, individuals selectively engage deeper, semantic encoding strategies for high value items (Cohen, Rissman, Suthana, Castel, & Knowlton, 2014). By another mechanism, information paired with value or reward is automatically strengthened in memory via dopaminergic projections from midbrain to hippocampus (Shohamy & Adcock, 2010). We hypothesized that the latter mechanism would primarily enhance recollection-based memory, while the former mechanism would strengthen both recollection and familiarity. We also hypothesized that providing interspersed tests during study is a key to encouraging selective engagement of strategies. To test these hypotheses, we presented participants with sets of words, and each word was associated with a high or low point value. In some experiments, free recall tests were given after each list. In all experiments, a recognition test was administered 5 minutes after the final word list. Process dissociation was accomplished via remember/know judgments at recognition, a recall test probing both item memory and memory for a contextual detail (word plurality), and a task dissociation combining a recognition test for plurality (intended to probe recollection) with a speeded item recognition test (to probe familiarity). When recall tests were administered after study lists, high value strengthened both recollection and familiarity. When memory was not tested after each study list, but rather only at the end, value increased recollection but not familiarity. These dual process dissociations suggest that interspersed recall tests guide learners' use of metacognitive control to selectively apply effective encoding strategies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Sex Differences in the Neural Correlates of Specific and General Autobiographical Memory

PubMed Central

Compère, Laurie; Sperduti, Marco; Gallarda, Thierry; Anssens, Adèle; Lion, Stéphanie; Delhommeau, Marion; Martinelli, Pénélope; Devauchelle, Anne-Dominique; Oppenheim, Catherine; Piolino, Pascale

2016-01-01

Autobiographical memory (AM) underlies the formation and temporal continuity over time of personal identity. The few studies on sex-related differences in AM suggest that men and women adopt different cognitive or emotional strategies when retrieving AMs. However, none of the previous works has taken into account the distinction between episodic autobiographical memory (EAM), consisting in the retrieval of specific events by means of mental time travel, and semantic autobiographical memory (SAM), which stores general personal events. Thus, it remains unclear whether differences in these strategies depend on the nature of the memory content to be retrieved. In the present study we employed functional MRI to examine brain activity underlying potential sex differences in EAM and SAM retrieval focusing on the differences in strategies related to the emotional aspects of memories while controlling for basic cognitive strategies. On the behavioral level, there was no significant sex difference in memory performances or subjective feature ratings of either type of AM. Activations common to men and women during AM retrieval were observed in a typical bilateral network comprising medial and lateral temporal regions, precuneus, occipital cortex as well as prefrontal cortex. Contrast analyses revealed that there was no difference between men and women in the EAM condition. In the SAM condition, women showed an increased activity, compared to men, in the dorsal anterior cingulate cortex, inferior parietal and precentral gyrus. Overall, these findings suggest that differential neural activations reflect sex-specific strategies related to emotional aspects of AMs, particularly regarding SAM. We propose that this pattern of activation during SAM retrieval reflects the cognitive cost linked to emotion regulation strategies recruited by women compared to men. These sex-related differences have interesting implications for understanding psychiatric disorders with differential sex prevalence and in which one of key features is overgenerality in AM. PMID:27378884

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

Memory and metamemory performance in Alzheimer's disease and healthy elderly: the Contextual Memory Test (CMT).

PubMed

Gil, N; Josman, N

2001-08-01

The purpose of the present study was to examine the ability of the Contextual Memory Test (CMT) to differentiate between elderly people suffering from Alzheimer's disease (AD) in comparison to healthy elderly people. Specifically, the objectives were to compare for differences between and within the groups on components of memory, including immediate and delayed recall as well as recognition. In addition, parameters of metamemory skills, such as general awareness, self-prediction of memory capacity, self-estimation, strategy use and use of contextual information, as well as the correlation between self-awareness and actual performance in both groups, were investigated. The sample consisted of 60 elderly participants, including 30 people diagnosed with AD who were assigned to the research group and 30 people matched for age, gender and educational level who were assigned to the control group. The results provide support for the hypothesis positing differences in memory performance between healthy elderly participants and those suffering from AD, particularly in immediate and delayed recall as well as in recognition. Moreover, findings indicate an improvement in memory performance under the cued condition (contextual), whereas improvement in the AD group proved to be significant only for immediate recall. The findings point to a distinct overestimation of memory ability predicted by both the AD and control groups. Following the memory task, however, the participants accurately estimated the number of items they remembered. In addition, significant correlations between the use of contextual and association strategies and the number of items remembered by both groups were obtained, in immediate as well as in delayed recall. Therefore, these findings support the CMT as a valuable memory and metamemory assessment tool for use with the AD population.

Competitive advantage for multiple-memory strategies in an artificial market

NASA Astrophysics Data System (ADS)

Mitman, Kurt E.; Choe, Sehyo C.; Johnson, Neil F.

2005-05-01

We consider a simple binary market model containing N competitive agents. The novel feature of our model is that it incorporates the tendency shown by traders to look for patterns in past price movements over multiple time scales, i.e. multiple memory-lengths. In the regime where these memory-lengths are all small, the average winnings per agent exceed those obtained for either (1) a pure population where all agents have equal memory-length, or (2) a mixed population comprising sub-populations of equal-memory agents with each sub-population having a different memory-length. Agents who consistently play strategies of a given memory-length, are found to win more on average -- switching between strategies with different memory lengths incurs an effective penalty, while switching between strategies of equal memory does not. Agents employing short-memory strategies can outperform agents using long-memory strategies, even in the regime where an equal-memory system would have favored the use of long-memory strategies. Using the many-body 'Crowd-Anticrowd' theory, we obtain analytic expressions which are in good agreement with the observed numerical results. In the context of financial markets, our results suggest that multiple-memory agents have a better chance of identifying price patterns of unknown length and hence will typically have higher winnings.

Self-guided strategy-adaption training for older adults: Transfer effects to everyday tasks.

PubMed

Bottiroli, Sara; Cavallini, Elena; Dunlosky, John; Vecchi, Tomaso; Hertzog, Christopher

2017-09-01

The goal of the present research was to examine the potential of a learner-oriented approach to improving older adults' performance in tasks that are similar to real-life situations that require strategic deployment of cognitive resources. A crucial element of this approach involves encouraging older adults to explicitly analyze tasks to consider how to adapt trained skills to a new task context. In an earlier study, a specialist-directed intervention produced training gains and transfer to some untrained memory tasks. In the present study, older adults received a manual instructing them about principles of task analysis, two memory strategies, and strategy adaptation. Self-guided strategy-adaption training involved practicing some memory tasks as well as instructions on how the trained skills could be applied to new tasks that were not practiced. The criterion tasks involved practice tasks, non-practiced tasks that were discussed in the manual, and transfer tasks that were never mentioned in the manual. Two of the tests were from the Everyday Cognition Battery (inductive reasoning and working memory). As compared to a waiting-list control group, older adults assigned to self-guided strategy-adaption training showed memory improvements on tasks that were practiced or discussed during training. Most important, the learner-oriented approach produced transfer to the everyday tasks. Our findings show the potential of instructing task appraisal processes as a basis for fostering transfer, including improving older adults' performance in simulated everyday tasks. Copyright © 2017 Elsevier B.V. All rights reserved.

The role of cognitive reserve and memory self-efficacy in compensatory strategy use: A structural equation approach.

PubMed

Simon, Christa; Schmitter-Edgecombe, Maureen

2016-08-01

The use of compensatory strategies plays an important role in the ability of older adults to adapt to late-life memory changes. Even with the benefits associated with compensatory strategy use, little research has explored specific mechanisms associated with memory performance and compensatory strategies. Rather than an individual's objective memory performance directly predicting their use of compensatory strategies, it is possible that some other variables are indirectly influencing that relationship. The purpose of this study was to: (a) examine the moderating effects of cognitive reserve (CR) and (b) evaluate the potential mediating effects of memory self-efficacy on the relationship between objective memory performance and compensatory strategy use. Two structural equation models (SEM) were used to evaluate CR (latent moderator model) and memory self-efficacy (mediator model) in a sample of 155 community-dwelling older adults over the age of 55. The latent variable moderator model indicated that CR was not substantiated as a moderator variable in this sample (p = .861). However, memory self-efficacy significantly mediated the association between objective memory performance and compensatory strategy use (β = .22, 95% confidence interval, CI [.002, .437]). More specifically, better objective memory was associated with lower compensatory strategy use because of its relation to higher memory self-efficacy. These findings provide initial support for an explanatory framework of the relation between objective memory and compensatory strategy use in a healthy older adult population by identifying the importance of an individual's memory perceptions.

Cognitive Symptom Management and Rehabilitation Therapy (CogSMART) for veterans with traumatic brain injury: pilot randomized controlled trial.

PubMed

Twamley, Elizabeth W; Jak, Amy J; Delis, Dean C; Bondi, Mark W; Lohr, James B

2014-01-01

Traumatic brain injury (TBI) can result in cognitive impairments and persistent postconcussive symptoms that limit functional recovery, including return to work. We evaluated a 12 wk compensatory cognitive training intervention (Cognitive Symptom Management and Rehabilitation Therapy [CogSMART]) in the context of supported employment for Veterans with mild to moderate TBI. Participants were randomly assigned to receive 12 wk of supported employment plus CogSMART or enhanced supported employment that controlled for therapist attention (control). CogSMART sessions were delivered by the employment specialist and included psychoeducation regarding TBI; strategies to improve sleep, fatigue, headaches, and tension; and compensatory cognitive strategies in the domains of prospective memory, attention, learning and memory, and executive functioning. Compared with controls, those assigned to supported employment plus CogSMART demonstrated significant reductions in postconcussive symptoms (Cohen d = 0.97) and improvements in prospective memory functioning (Cohen d = 0.72). Effect sizes favoring CogSMART for posttraumatic stress disorder symptom severity, depressive symptom severity, and attainment of competitive work within 14 wk were in the small to medium range (Cohen d = 0.35-0.49). Those who received CogSMART rated the intervention highly. Results suggest that adding CogSMART to supported employment may improve postconcussive symptoms and prospective memory. These effects, as well as smaller effects on psychiatric symptoms and ability to return to work, warrant replication in a larger trial.

Evaluation of a caregiver education program to support memory and communication in dementia: a controlled pretest-posttest study with nursing home staff.

PubMed

Broughton, Megan; Smith, Erin R; Baker, Rosemary; Angwin, Anthony J; Pachana, Nancy A; Copland, David A; Humphreys, Michael S; Gallois, Cindy; Byrne, Gerard J; Chenery, Helen J

2011-11-01

There is a need for simple multimedia training programs designed to upskill the dementia care workforce. A DVD-based training program entitled RECAPS and MESSAGE has been designed to provide caregivers with strategies to support memory and communication in people with dementia. The aims of this study were: (1) to evaluate the effects of the RECAPS and MESSAGE training on knowledge of support strategies, and caregiver satisfaction, in nursing home care staff, and (2) to evaluate staff opinion of the training. A multi-centre controlled pretest-posttest trial was conducted between June 2009 and January 2010, with baseline, immediately post-training and 3-month follow-up assessment. Four nursing homes in Queensland, Australia. All care staff were invited to participate. Of the 68 participants who entered the study, 52 (37 training participants and 15 controls) completed outcome measures at baseline and 3-month follow-up. 63.5% of participants were nursing assistants, 25% were qualified nurses and 11.5% were recreational/activities officers. The training and control groups were compared on the following outcomes: (1) knowledge of memory and communication support strategies, and (2) caregiver satisfaction. In the training group, the immediate effects of training on knowledge, and the effects of role (nurse, nursing assistant, recreational staff) on both outcome measures, were also examined. Staff opinion of the training was assessed immediately post-training and at 3-month follow-up. The training group showed a significant improvement in knowledge of support strategies from baseline to immediately post-training (p=0.001). Comparison of the training and control groups revealed a significant increase in knowledge for the training group (p=0.011), but not for the control group (p=0.33), between baseline and 3-month follow-up. Examination of caregiver satisfaction by care staff role in the training group revealed that only the qualified nurses showed higher levels of caregiver satisfaction at 3-month follow-up (p=0.013). Staff rated the training positively both for usefulness and applicability. The RECAPS and MESSAGE training improved nursing home care staff's knowledge of support strategies for memory and communication, and gains were maintained at 3-month follow-up. Moreover, the training was well received by staff. Copyright © 2011 Elsevier Ltd. All rights reserved.

Rehabilitation of memory following brain injury (ReMemBrIn): study protocol for a randomised controlled trial.

PubMed

das Nair, Roshan; Lincoln, Nadina B; Ftizsimmons, Deborah; Brain, Nicola; Montgomery, Alan; Bradshaw, Lucy; Drummond, Avril; Sackley, Catherine; Newby, Gavin; Thornton, Jim; Stapleton, Sandip; Pink, Anthony

2015-01-06

Impairments of memory are commonly reported by people with traumatic brain injuries (TBI). Such deficits are persistent, debilitating, and can severely impact quality of life. Currently, many do not routinely receive follow-up appointments for residual memory problems following discharge. This is a multi-centre, randomised controlled trial investigating the clinical and cost-effectiveness of a group-based memory rehabilitation programme. Three hundred and twelve people with a traumatic brain injury will be randomised from four centres. Participants will be eligible if they had a traumatic brain injury more than 3 months prior to recruitment, have memory problems, are 18 to 69 years of age, are able to travel to one of our centres and attend group sessions, and are able to give informed consent. Participants will be randomised in clusters of 4 to 6 to the group rehabilitation intervention or to usual care. Intervention groups will receive 10 weekly sessions of a manualised memory rehabilitation programme, which has been developed in previous pilot studies. The intervention will include restitution strategies to retrain impaired memory functions and compensation strategies to enable participants to cope with their memory problems. All participants will receive a follow-up postal questionnaire and an assessment by a research assistant at 6 and 12 months post-randomisation. The primary outcome is the Everyday Memory Questionnaire at 6 months. Secondary outcomes include the Rivermead Behavioural Memory Test-3, General Health Questionnaire-30, health related quality of life, cost-effectiveness analysis determined by the EQ-5D and a service use questionnaire, individual goal attainment, European Brain Injury Questionnaire (patient and relative versions), and the Everyday Memory Questionnaire-relative version. The primary analysis will be based on intention to treat. A mixed-model regression analysis of the Everyday Memory Questionnaire at 6 months will be used to estimate the effect of the group memory rehabilitation programme. The study will hopefully provide robust evidence regarding the clinical and cost-effectiveness of a group-based memory rehabilitation intervention for civilians and military personnel following TBI. We discuss our decision-making regarding choice of outcome measures and control group, and the unique challenges to recruiting people with memory problems to trials. ISRCTN65792154; Date: 18 October 2012.

Goals-feedback conditions and episodic memory: Mechanisms for memory gains in older and younger adults.

PubMed

West, Robin L; Dark-Freudeman, Alissa; Bagwell, Dana K

2009-02-01

Research has established that challenging memory goals always lead to score increases for younger adults, and can increase older adults' scores under supportive conditions. This study examined beliefs and on-task effort as potential mechanisms for these self-regulatory gains, in particular to learn whether episodic memory gains across multiple trials of shopping list recall are controlled by the same factors for young and old people. Goals with feedback led to higher recall and strategic categorisation than a control condition. Strategy usage was the strongest predictor of gains over trials for both age groups. Age, goal condition, and effort also predicted scores across the entire sample. Older adults' gains, but not younger adults' gains, were affected significantly by the interaction of self-efficacy beliefs and goal condition, and condition interacted with locus of control to predict younger adult gains. These results emphasise the importance of self-regulatory effort and positive beliefs for facilitating goal-related memory gains.

Super-Memorizers Are Not Super-Recognizers

PubMed Central

Ramon, Meike; Miellet, Sebastien; Dzieciol, Anna M.; Konrad, Boris Nikolai

2016-01-01

Humans have a natural expertise in recognizing faces. However, the nature of the interaction between this critical visual biological skill and memory is yet unclear. Here, we had the unique opportunity to test two individuals who have had exceptional success in the World Memory Championships, including several world records in face-name association memory. We designed a range of face processing tasks to determine whether superior/expert face memory skills are associated with distinctive perceptual strategies for processing faces. Superior memorizers excelled at tasks involving associative face-name learning. Nevertheless, they were as impaired as controls in tasks probing the efficiency of the face system: face inversion and the other-race effect. Super memorizers did not show increased hippocampal volumes, and exhibited optimal generic eye movement strategies when they performed complex multi-item face-name associations. Our data show that the visual computations of the face system are not malleable and are robust to acquired expertise involving extensive training of associative memory. PMID:27008627

Super-Memorizers Are Not Super-Recognizers.

PubMed

Ramon, Meike; Miellet, Sebastien; Dzieciol, Anna M; Konrad, Boris Nikolai; Dresler, Martin; Caldara, Roberto

2016-01-01

Humans have a natural expertise in recognizing faces. However, the nature of the interaction between this critical visual biological skill and memory is yet unclear. Here, we had the unique opportunity to test two individuals who have had exceptional success in the World Memory Championships, including several world records in face-name association memory. We designed a range of face processing tasks to determine whether superior/expert face memory skills are associated with distinctive perceptual strategies for processing faces. Superior memorizers excelled at tasks involving associative face-name learning. Nevertheless, they were as impaired as controls in tasks probing the efficiency of the face system: face inversion and the other-race effect. Super memorizers did not show increased hippocampal volumes, and exhibited optimal generic eye movement strategies when they performed complex multi-item face-name associations. Our data show that the visual computations of the face system are not malleable and are robust to acquired expertise involving extensive training of associative memory.

Self-Regulation and Recall: Growth Curve Modeling of Intervention Outcomes for Older Adults

PubMed Central

West, Robin L.; Hastings, Erin C.

2013-01-01

Memory training has often been supported as a potential means to improve performance for older adults. Less often studied are the characteristics of trainees that benefit most from training. Using a self-regulatory perspective, the current project examined a latent growth curve model to predict training-related gains for middle-aged and older adult trainees from individual differences (e.g., education), information processing skills (strategy use) and self-regulatory factors such as self-efficacy, control, and active engagement in training. For name recall, a model including strategy usage and strategy change as predictors of memory gain, along with self-efficacy and self-efficacy change, showed comparable fit to a more parsimonious model including only self-efficacy variables as predictors. The best fit to the text recall data was a model focusing on self-efficacy change as the main predictor of memory change, and that model showed significantly better fit than a model also including strategy usage variables as predictors. In these models, overall performance was significantly predicted by age and memory self-efficacy, and subsequent training-related gains in performance were best predicted directly by change in self-efficacy (text recall), or indirectly through the impact of active engagement and self-efficacy on gains (name recall). These results underscore the benefits of targeting self-regulatory factors in intervention programs designed to improve memory skills. PMID:21604891

Self-regulation and recall: growth curve modeling of intervention outcomes for older adults.

PubMed

West, Robin L; Hastings, Erin C

2011-12-01

Memory training has often been supported as a potential means to improve performance for older adults. Less often studied are the characteristics of trainees that benefit most from training. Using a self-regulatory perspective, the current project examined a latent growth curve model to predict training-related gains for middle-aged and older adult trainees from individual differences (e.g., education), information processing skills (strategy use) and self-regulatory factors such as self-efficacy, control, and active engagement in training. For name recall, a model including strategy usage and strategy change as predictors of memory gain, along with self-efficacy and self-efficacy change, showed comparable fit to a more parsimonious model including only self-efficacy variables as predictors. The best fit to the text recall data was a model focusing on self-efficacy change as the main predictor of memory change, and that model showed significantly better fit than a model also including strategy usage variables as predictors. In these models, overall performance was significantly predicted by age and memory self-efficacy, and subsequent training-related gains in performance were best predicted directly by change in self-efficacy (text recall), or indirectly through the impact of active engagement and self-efficacy on gains (name recall). These results underscore the benefits of targeting self-regulatory factors in intervention programs designed to improve memory skills.

Through the Immune Looking Glass: A Model for Brain Memory Strategies

PubMed Central

Sánchez-Ramón, Silvia; Faure, Florence

2016-01-01

The immune system (IS) and the central nervous system (CNS) are complex cognitive networks involved in defining the identity (self) of the individual through recognition and memory processes that enable one to anticipate responses to stimuli. Brain memory has traditionally been classified as either implicit or explicit on psychological and anatomical grounds, with reminiscences of the evolutionarily-based innate-adaptive IS responses. Beyond the multineuronal networks of the CNS, we propose a theoretical model of brain memory integrating the CNS as a whole. This is achieved by analogical reasoning between the operational rules of recognition and memory processes in both systems, coupled to an evolutionary analysis. In this new model, the hippocampus is no longer specifically ascribed to explicit memory but rather it both becomes part of the innate (implicit) memory system and tightly controls the explicit memory system. Alike the antigen presenting cells for the IS, the hippocampus would integrate transient and pseudo-specific (i.e., danger-fear) memories and would drive the formation of long-term and highly specific or explicit memories (i.e., the taste of the Proust’s madeleine cake) by the more complex and recent, evolutionarily speaking, neocortex. Experimental and clinical evidence is provided to support the model. We believe that the singularity of this model’s approximation could help to gain a better understanding of the mechanisms operating in brain memory strategies from a large-scale network perspective. PMID:26869886

How to Study: The Neglected Basic.

ERIC Educational Resources Information Center

Wilcox, Wayne C.; Wilson, Brent G.

This paper examines knowledge of studying--knowing how and when to apply study strategies. Study strategies may be classified into three categories: memory strategies, comprehension strategies, and problem-solving strategies. Memory-study strategies help students remember what they study. Five attributes often characterize memory strategies:…

Cognitive retraining for organizational impairment in obsessive-compulsive disorder.

PubMed

Buhlmann, Ulrike; Deckersbach, Thilo; Engelhard, Iris; Cook, Laura M; Rauch, Scott L; Kathmann, Norbert; Wilhelm, Sabine; Savage, Cary R

2006-11-15

Individuals with obsessive-compulsive disorder (OCD) have difficulties in organizing information during encoding associated with subsequent memory impairments. This study was designed to investigate whether impairments in organization in individuals with OCD can be alleviated with cognitive training. Thirty-five OCD subjects and 36 controls copied and recalled the Rey-Osterrieth Complex Figure Test (RCFT) [Osterrieth, P.A., 1944. Le test de copie d'une figure complexe: Contribution a l'étude de la perception et de la memoire (The test of copying a complex figure: A contribution to the study of perception and memory). Archive de Psychologie 30, 286-350.] before being randomly assigned to a training or non-training condition. The training condition was designed to improve the ability to organize complex visuospatial information in a meaningful way. The intervention phase was followed by another copy and recall trial of the RCFT. Both OCD and control subjects who underwent training improved more in organization and memory than subjects who did not receive organizational training, providing evidence that the training procedure was effective. OCD subjects improved more in organizational during encoding than control subjects, irrespective of whether or not they had received training. This suggests that organization impairment in OCD affects primarily the ability to spontaneously utilize strategies when faced with complex, ambiguous information but that the ability to implement such strategies when provided with additional trials is preserved. These findings support a distinction in OCD between failure to utilize a strategy and incapacity to implement a strategy.

Coordination of size-control, reproduction and generational memory in freshwater planarians

NASA Astrophysics Data System (ADS)

Yang, Xingbo; Kaj, Kelson; Schwab, David; Collins, Eva-Maria

Uncovering the mechanisms that control size, growth, and division rates of systems reproducing through binary division means understanding basic principles of their life cycle. Recent work has focused on how division rates are regulated in bacteria and yeast, but this question has not yet been addressed in more complex, multicellular organisms. We have acquired a unique large-scale data set on the growth and asexual reproduction of two freshwater planarian species, Dugesia japonica and Dugesia tigrina, which reproduce by transverse fission and succeeding regeneration of head and tail pieces into new worms. We developed a new additive theoretical model that mixes multiple size control strategies based on worm size, growth, and waiting time. Our model quantifies the proportions of each strategy in the mixed dynamics, revealing the ability of the two planarian species to utilize different strategies in a coordinated manner for size control. Additionally, we found that head and tail offspring of both species employ different mechanisms to monitor and trigger their reproduction cycles. Finally, we show that generation-dependent memory effects in planarians need to be taken into account to accurately capture the experimental data.

Spatial working memory function in twins with schizophrenia and bipolar disorder.

PubMed

Pirkola, Tiia; Tuulio-Henriksson, Annamari; Glahn, David; Kieseppä, Tuula; Haukka, Jari; Kaprio, Jaakko; Lönnqvist, Jouko; Cannon, Tyrone D

2005-12-15

Family studies are in conflict as to whether schizophrenia and bipolar disorder have independent genetic etiologies. Given the relatively low prevalence (approximately 1%) of these disorders, the use of quantitative endophenotypic markers of genetic liability might provide a more sensitive strategy for evaluating their genetic overlap. We have previously demonstrated that spatial working memory deficits increase in a dose-dependent fashion with increasing genetic proximity to a proband among the unaffected co-twins of schizophrenic patients. Here, we evaluated whether such deficits might also mark genetic susceptibility to bipolar disorder. The Wechsler Memory Scale-Revised Visual Memory Span and Digit Span subtests were administered to 46 schizophrenic patients, 32 of their unaffected co-twins, 22 bipolar patients, 16 of their unaffected co-twins, and 100 control twins, representing unselectively nationwide twin samples. Schizophrenic patients and their unaffected co-twins performed significantly worse than control subjects on the spatial working memory task, whereas only the schizophrenic patients performed significantly below the control subjects on the verbal working memory task. Neither bipolar patients nor their unaffected co-twins differed from control subjects on these measures. Our findings support the hypothesis that impairment in spatial working memory might effectively reflect an expression of genetic liability to schizophrenia but less clearly to bipolar disorder.

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.

Is short-term memory involved in decision making? Evidence from a short-term memory patient.

PubMed

Gozzi, Marta; Papagno, Costanza

2007-03-01

It is reasonable to suggest that working memory (WM; Baddeley & Hitch, 1974) is involved in decision making, as decision making is dependent on the ability to remember and update past choices and outcomes. However, contradictory results have been reported in the literature concerning the role of two of its components, namely the central executive and the phonological loop. In order to investigate the role of these components in the decision-making process, we tested a patient with intact central executive but impaired phonological loop on a laboratory decision-making task involving hypothetical gambles (gambling task, GT). When tested in a no-load condition (simple keypress task), her performance was not significantly different from that of matched controls. We also verified whether her performance would be affected differently by memory-load when compared with control subjects. The memory task (holding a string of letters in memory) loaded WM without incurring number-number interference. When the memory-load was imposed during the GT, both the patient and the controls showed a decline in performance, but the strategy they adopted differed. Possible explanations are discussed. In conclusion, our results suggest that the phonological loop is not directly involved in decision making.

Cognitive Rehabilitation for Attention and Memory in people with Multiple Sclerosis: study protocol for a randomised controlled trial (CRAMMS).

PubMed

Lincoln, Nadina B; das Nair, Roshan; Bradshaw, Lucy; Constantinescu, Cris S; Drummond, Avril E R; Erven, Alexandra; Evans, Amy L; Fitzsimmons, Deborah; Montgomery, Alan A; Morgan, Miriam

2015-12-08

People with multiple sclerosis have problems with memory and attention. Cognitive rehabilitation is a structured set of therapeutic activities designed to retrain an individual's memory and other cognitive functions. Cognitive rehabilitation may be provided to teach people strategies to cope with these problems, in order to reduce the impact on everyday life. The effectiveness of cognitive rehabilitation for people with multiple sclerosis has not been established. This is a multi-centre, randomised controlled trial investigating the clinical and cost-effectiveness of a group-based cognitive rehabilitation programme for attention and memory problems for people with multiple sclerosis. Four hundred people with multiple sclerosis will be randomised from at least four centres. Participants will be eligible if they have memory problems, are 18 to 69 years of age, are able to travel to attend group sessions and give informed consent. Participants will be randomised in a ratio of 6:5 to the group rehabilitation intervention plus usual care or usual care alone. Intervention groups will receive 10 weekly sessions of a manualised cognitive rehabilitation programme. The intervention will include both restitution strategies to retrain impaired attention and memory functions and compensation strategies to enable participants to cope with their cognitive problems. All participants will receive a follow-up questionnaire and an assessment by a research assistant at 6 and 12 months after randomisation. The primary outcome is the Multiple Sclerosis Impact Scale (MSIS) Psychological subscale at 12 months. Secondary outcomes include the Everyday Memory Questionnaire, General Health Questionnaire-30, EQ-5D and a service use questionnaire from participants, and the Everyday Memory Questionnaire-relative version and Carer Strain Index from a relative or friend. The primary analysis will be based on intention to treat. A mixed-model regression analysis of the MSIS Psychological subscale at 12 months will be used to estimate the effect of the group cognitive rehabilitation programme. The study will provide evidence regarding the clinical and cost-effectiveness of a group-based cognitive rehabilitation programme for attention and memory problems in people with multiple sclerosis. ISRCTN09697576 . Registered 14 August 2014.

Evaluation of the Implications of Nanoscale Architectures on Contextual Knowledge Discovery and Memory: Self-Assembled Architectures and Memory

DTIC Science & Technology

2008-05-01

patterns. Our strategy to nucleate Ag nanoparticles has been to use a templating protein (e.g., streptavidin) that has been chemically pre- charged with...assembly is used to direct the formation of switching devices and wires to create logic circuitry, memory, and I/O interfaces . We can control the reaction...determines the formation of structures (through complementarity ). Sequence design is important because it determines many aspects of the target DNA

Selective inhibition of phosphodiesterase 5 enhances glutamatergic synaptic plasticity and memory in mice.

PubMed

Uthayathas, Subramaniam; Parameshwaran, Kodeeswaran; Karuppagounder, Senthilkumar S; Ahuja, Manuj; Dhanasekaran, Muralikrishnan; Suppiramaniam, Vishnu

2013-11-01

Phosphodiesterases (PDEs) belong to a family of proteins that control metabolism of cyclic nucleotides. Targeting PDE5, for enhancing cellular function, is one of the therapeutic strategies for male erectile dysfunction. We have investigated whether in vivo inhibition of PDE5, which is expressed in several brain regions, will enhance memory and synaptic transmission in the hippocampus of healthy mice. We have found that acute administration of sildenafil, a specific PDE5 inhibitor, enhanced hippocampus-dependent memory tasks. To elucidate the underlying mechanism in the memory enhancement, effects of sildenafil on long-term potentiation (LTP) were measured. The level of LTP was significantly elevated, with concomitant increases in basal synaptic transmission, in mice treated with sildenafil (1 mg/kg/day) for 15 days compared to control mice. These results suggest that moderate PDE5 inhibition enhances memory by increasing synaptic plasticity and transmission in the hippocampus. Copyright © 2013 Wiley Periodicals, Inc.

Cognitive and memory training in adults at risk of dementia: A Systematic Review

PubMed Central

2011-01-01

Background Effective non-pharmacological cognitive interventions to prevent Alzheimer's dementia or slow its progression are an urgent international priority. The aim of this review was to evaluate cognitive training trials in individuals with mild cognitive impairment (MCI), and evaluate the efficacy of training in memory strategies or cognitive exercises to determine if cognitive training could benefit individuals at risk of developing dementia. Methods A systematic review of eligible trials was undertaken, followed by effect size analysis. Cognitive training was differentiated from other cognitive interventions not meeting generally accepted definitions, and included both cognitive exercises and memory strategies. Results Ten studies enrolling a total of 305 subjects met criteria for cognitive training in MCI. Only five of the studies were randomized controlled trials. Meta-analysis was not considered appropriate due to the heterogeneity of interventions. Moderate effects on memory outcomes were identified in seven trials. Cognitive exercises (relative effect sizes ranged from .10 to 1.21) may lead to greater benefits than memory strategies (.88 to -1.18) on memory. Conclusions Previous conclusions of a lack of efficacy for cognitive training in MCI may have been influenced by not clearly defining the intervention. Our systematic review found that cognitive exercises can produce moderate-to-large beneficial effects on memory-related outcomes. However, the number of high quality RCTs remains low, and so further trials must be a priority. Several suggestions for the better design of cognitive training trials are provided. PMID:21942932

A New Strategy to Prepare Polymer-based Shape Memory Elastomers.

PubMed

Song, Shijie; Feng, Jiachun; Wu, Peiyi

2011-10-04

A new strategy that utilizes the microphase separation of block copolymer and phase transition of small molecules for preparing polymer-based shape memory elastomer has been proposed. According to this strategy, a novel kind of shape memory elastomer comprising styrene-b-(ethylene-co-butylene)-b-styrene (SEBS) and paraffin has been prepared. Because paraffins are midblock-selective molecules for SEBS, they will preferentially enter and swell EB blocks supporting paraffins as an excellent switch phase for shape memory effect. Microstructures of SEBS/paraffin composites have been characterized by transmission electron microscopy, polarized light microscopy, and differential scanning calorimetry. The composites demonstrate various phase morphologies with regard to different paraffin loading. It has been found that under low paraffin loading, all the paraffins precisely embed in and swell EB-rich domains. While under higher loading, part of the paraffins become free and a larger-scaled phase separation has been observed. However, within wide paraffin loadings, all composites show good shape fixing, shape recovery performances, and improved tensile properties. Compared to the reported methods for shape memory elastomers preparation, this method not only simplifies the fabrication procedure from raw materials to processing but also offers a controllable approach for the optimization of shape memory properties as well as balancing the rigidity and softness of the material. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Working Memory Capacity and Reading Skill Moderate the Effectiveness of Strategy Training in Learning from Hypertext

ERIC Educational Resources Information Center

Naumann, Johannes; Richter, Tobias; Christmann, Ursula; Groeben, Norbert

2008-01-01

Cognitive and metacognitive strategies are particularly important for learning with hypertext. The effectiveness of strategy training, however, depends on available working memory resources. Thus, especially learners high on working memory capacity can profit from strategy training, while learners low on working memory capacity might easily be…

Would transcranial direct current stimulation (tDCS) enhance the effects of working memory training in older adults with mild neurocognitive disorder due to Alzheimer's disease: study protocol for a randomized controlled trial.

PubMed

Cheng, Calvin P W; Chan, Sandra S M; Mak, Arthur D P; Chan, Wai Chi; Cheng, Sheung Tak; Shi, Lin; Wang, Defeng; Lam, Linda Chiu-Wa

2015-10-24

There has been longstanding interesting in cognitive training for older adults with cognitive impairment. In this study, we will investigate the effects of working memory training, and explore augmentation strategies that could possibly consolidate the effects in older adults with mild neurocognitive disorder. Transcranial direct current stimulation (tDCS) has been demonstrated to affect the neuronal excitability and reported to enhance memory performance. As tDCS may also modulate cognitive function through changes in neuroplastic response, it would be adopted as an augmentation strategy for working memory training in the present study. This is a 4-week intervention double-blind randomized controlled trial (RCT) of tDCS. Chinese older adults (aged 60 to 90 years) with mild neurocognitive disorder due to Alzheimer's disease (DSM-5 criteria) would be randomized into a 4-week intervention of either tDCS-working memory (DCS-WM), tDCS-control cognitive training (DCS-CC), and sham tDCS-working memory (WM-CD) groups. The primary outcome would be working memory test - the n-back task performance and the Chinese version of the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog). Secondary outcomes would be test performance of specific cognitive domains and mood. Intention-to-treat analysis would be carried out. Changes of efficacy indicators with time and intervention would be tested with mixed effect models. This study adopts the theory of neuroplasticity to evaluate the potential cognitive benefits of non-invasive electrical brain stimulation, working memory training and dual stimulation in older adults at risk of cognitive decline. It would also examine the tolerability, program adherence and adverse effects of this novel intervention. Information would be helpful for further research of dementia prevention studies. ChiCTR-TRC- 14005036 Date of registration: 31 July 2014.

[Subjective memory complaints, perceived stress and coping strategies in young adults].

PubMed

Molina-Rodriguez, Sergio; Pellicer-Porcar, Olga; Mirete-Fructuoso, Marcos; Martinez-Amoros, Estefanía

2016-04-16

Subjective memory complaints are becoming more and more frequent among young adults. There are currently no studies in the literature that analyse the relation among memory complaints, perceived stress and coping strategies as a whole in young adults. To determine the contribution made by perceived stress and different coping strategies on subjective memory complaints in healthy young adults. The sample consisted of 299 university students, of whom 71.6% were women, with a mean age of 22.54 ± 4.73 years. The variable 'memory complaints' was measured with the memory failures questionnaire; the variable 'perceived stress' was measured with the perceived stress scale, and the variables referring to coping strategies were measured using the coping strategies inventory. The variables that made a higher contribution to the variance of the memory complaints are, first, perceived stress and positive problem-focused coping strategies, and, second, negative coping strategies focused on the emotion and on the problem. The positive emotion-focused coping strategies do not make any contribution. Again we find evidence of the influence of stress on memory processes. The use of positive problem-focused coping strategies, such as cognitive restructuring and problem-solving, can be beneficial to lessen the presence of memory complaints. Further research on this matter is warranted.

The effect of encoding strategy on the neural correlates of memory for faces.

PubMed

Bernstein, Lori J; Beig, Sania; Siegenthaler, Amy L; Grady, Cheryl L

2002-01-01

Encoding and recognition of unfamiliar faces in young adults were examined using positron emission tomography to determine whether different encoding strategies would lead to encoding/retrieval differences in brain activity. Three types of encoding were compared: a 'deep' task (judging pleasantness/unpleasantness), a 'shallow' task (judging right/left orientation), and an intentional learning task in which subjects were instructed to learn the faces for a subsequent memory test but were not provided with a specific strategy. Memory for all faces was tested with an old/new recognition test. A modest behavioral effect was obtained, with deeply-encoded faces being recognized more accurately than shallowly-encoded or intentionally-learned faces. Regardless of encoding strategy, encoding activated a primarily ventral system including bilateral temporal and fusiform regions and left prefrontal cortices, whereas recognition activated a primarily dorsal set of regions including right prefrontal and parietal areas. Within encoding, the type of strategy produced different brain activity patterns, with deep encoding being characterized by left amygdala and left anterior cingulate activation. There was no effect of encoding strategy on brain activity during the recognition conditions. Posterior fusiform gyrus activation was related to better recognition accuracy in those conditions encouraging perceptual strategies, whereas activity in left frontal and temporal areas correlated with better performance during the 'deep' condition. Results highlight three important aspects of face memory: (1) the effect of encoding strategy was seen only at encoding and not at recognition; (2) left inferior prefrontal cortex was engaged during encoding of faces regardless of strategy; and (3) differential activity in fusiform gyrus was found, suggesting that activity in this area is not only a result of automatic face processing but is modulated by controlled processes.

Effect of organizational strategy on visual memory in patients with schizophrenia.

PubMed

Kim, Myung-Sun; Namgoong, Yoon; Youn, Tak

2008-08-01

The aim of the present study was to examine how copy organization mediated immediate recall among patients with schizophrenia using the Rey-Osterrieth Complex Figure Test (ROCF). The Boston Qualitative Scoring System (BQSS) was applied for qualitative and quantitative analyses of ROCF performances. Subjects included 20 patients with schizophrenia and 20 age- and gender-matched healthy controls. During the copy condition, the schizophrenia group and the control group differed in fragmentation; during the immediate recall condition, the two groups differed in configural presence and planning; and during the delayed recall condition, they differed in several qualitative measurements, including configural presence, cluster presence/placement, detail presence/placement, fragmentation, planning, and neatness. The two groups also differed in several quantitative measurements, including immediate presence and accuracy, immediate retention, delayed retention, and organization. Although organizational strategies used during the copy condition mediated the difference between the two groups during the immediate recall condition, group also had a significant direct effect on immediate recall. Schizophrenia patients are deficient in visual memory, and a piecemeal approach to the figure and organizational deficit seem to be related to the visual memory deficit. But schizophrenia patients also appeared to have some memory problems, including retention and/or retrieval deficits.

The relation between navigation strategy and associative memory: An individual differences approach.

PubMed

Ngo, Chi T; Weisberg, Steven M; Newcombe, Nora S; Olson, Ingrid R

2016-04-01

Although the hippocampus is implicated in both spatial navigation and associative memory, very little is known about whether individual differences in the 2 domains covary. People who prefer to navigate using a hippocampal-dependent place strategy may show better performance on associative memory tasks than those who prefer a caudate-dependent response strategy (Bohbot, Gupta, Banner, & Dahmani, 2011), but not all studies suggest such an effect (Woollett & Maguire, 2009, 2012). Here we tested nonexpert young adults and found that preference for a place strategy positively correlated with spatial (object-location) associative memory performance but did not correlate with nonspatial (face-name) associative memory performance. Importantly, these correlations differed from each other, indicating that the relation between navigation strategy and associative memory is specific to the spatial domain. In addition, the 2 associative memory tasks significantly correlated, suggesting that object-location memory taps into processes relevant to both hippocampal-dependent navigation and nonspatial associative memory. Our findings also suggest that individual differences in spatial associative memory may account for some of the variance in navigation strategies. (c) 2016 APA, all rights reserved).

Memory strategy training in children with cerebral infarcts related to sickle cell disease.

PubMed

Yerys, Benjamin E; White, Desirée A; Salorio, Cynthia F; McKinstry, Robert; Moinuddin, Asif; DeBaun, Michael

2003-06-01

Cerebral infarcts occur in approximately 30% of children with sickle cell disease (SCD), but little information exists regarding remediation of associated cognitive deficits. The authors examined the benefits of training children with infarcts to use memory strategies. Six children with SCD-related infarcts received academic tutoring; three of these children received additional training in memory strategies (silent rehearsal to facilitate short-term memory and semantic organization to facilitate long-term memory). The performance of children receiving strategy training appeared to improve more than that of children receiving only tutoring. Memory in children with SCD-related infarcts may be enhanced through strategy training.

Enhancement of Speed Margins for 16× Digital Versatile Disc-Random Access Memory

NASA Astrophysics Data System (ADS)

Watanabe, Koichi; Minemura, Hiroyuki; Miyamoto, Makoto; Iimura, Makoto

2006-02-01

We have evaluated the speed margins of write/read 16× digital versatile disc-random access memory (DVD-RAM) test discs using write strategies for 6--16× constant angular velocity (CAV) control. Our approach is to determine the writing parameters for the middle zones by interpolating the zone numbers. Using this interpolation strategy, we successfully obtained overwrite jitter values of less than 8% and bit error rates of less than 10-5 in 6--16× DVD-RAM. Moreover, we confirmed that the speed margins were ± 20% for a 6--16× CAV.

The Relationship between Learning Style Preferences and Memory Strategy use in Adults.

PubMed

Dirette, Diane Powers; Anderson, Michele A

2016-07-01

Deficits in working memory are pervasive, resistant to remediation and significantly impact a persons ability to perform activities of daily living. Internal strategies are effective for improving working memory. Learning style preferences may influence the use of various internal working memory strategies. This study compares the use of internal working memory strategies among four different learning style preferences; converger, diverger, assimilator and accommodator. A non-experimental group design was used to compare the use of internal working memory strategies and learning style preferences among 110 adults. There were some significant differences in the types of strategies used according to learning style preferences. Knowing the learning style preference of clients may help occupational therapists better tailor cognitive rehabilitation treatments to meet the client's needs.

Multifaceted Prospective Memory Intervention to Improve Medication Adherence.

PubMed

Insel, Kathie C; Einstein, Gilles O; Morrow, Daniel G; Koerner, Kari M; Hepworth, Joseph T

2016-03-01

To test whether a multifaceted prospective memory intervention improved adherence to antihypertensive medications and to assess whether executive function and working memory processes moderated the intervention effects. Two-group longitudinal randomized control trial. Community. Individuals aged 65 and older without signs of dementia or symptoms of severe depression who were self-managing prescribed medication. After 4 weeks of initial adherence monitoring using a medication event monitoring system, individuals with 90% or less adherence were randomly assigned to groups. The prospective memory intervention was designed to provide strategies that switch older adults from relying on executive function and working memory processes (that show effects of cognitive aging) to mostly automatic associative processes (that are relatively spared with normal aging) for remembering to take medications. Strategies included establishing a routine, establishing cues strongly associated with medication taking actions, performing the action immediately upon thinking about it, using a medication organizer, and imagining medication taking to enhance encoding and improve cuing. There was significant improvement in adherence in the intervention group (57% at baseline to 78% after the intervention), but most of these gains were lost after 5 months. The control condition started at 68% and was stable during the intervention, but dropped to 62%. Executive function and working memory moderated the intervention effect, with the intervention producing greater benefit for those with lower executive function and working memory. The intervention improved adherence, but the benefits were not sustained. Further research is needed to determine how to sustain the substantial initial benefits. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

Autobiographical memory of the recent past following frontal cortex or temporal lobe excisions.

PubMed

Thaiss, Laila; Petrides, Michael

2008-08-01

Previous research has raised questions regarding the necessity of the frontal cortex in autobiographical memory and the role that it plays in actively retrieving contextual information associated with personally relevant events. Autobiographical memory was studied in patients with unilateral excisions restricted to the frontal cortex or temporal lobe involving the amygdalo-hippocampal region and in normal controls using an event-sampling method. We examined accuracy of free recall, use of strategies during retrieval and memory for specific aspects of the autobiographical events, including temporal order. Patients with temporal lobe excisions were impaired in autobiographical recall. By contrast, patients with frontal cortical excisions exhibited normal autobiographical recall but were less likely to use temporal order spontaneously to organize event retrieval. Instruction to organize retrieval by temporal order failed to improve recall in temporal lobe patients and increased the incidence of plausible intrusion errors in left temporal patients. In contrast, patients with frontal cortical excisions now surpassed control subjects in recall of autobiographical events. Furthermore, the retrieval accuracy for the temporal order of diary events was not impaired in these patients. In a subsequent cued recall test, temporal lobe patients were impaired in their memory for the details of the diary events and their context. In conclusion, a basic impairment in autobiographical memory (including memory for temporal context) results from damage to the temporal lobe and not the frontal cortex. Patients with frontal excisions fail to use organizational strategies spontaneously to aid retrieval but can use these effectively if instructed to do so.

Cognitive niches: an ecological model of strategy selection.

PubMed

Marewski, Julian N; Schooler, Lael J

2011-07-01

How do people select among different strategies to accomplish a given task? Across disciplines, the strategy selection problem represents a major challenge. We propose a quantitative model that predicts how selection emerges through the interplay among strategies, cognitive capacities, and the environment. This interplay carves out for each strategy a cognitive niche, that is, a limited number of situations in which the strategy can be applied, simplifying strategy selection. To illustrate our proposal, we consider selection in the context of 2 theories: the simple heuristics framework and the ACT-R (adaptive control of thought-rational) architecture of cognition. From the heuristics framework, we adopt the thesis that people make decisions by selecting from a repertoire of simple decision strategies that exploit regularities in the environment and draw on cognitive capacities, such as memory and time perception. ACT-R provides a quantitative theory of how these capacities adapt to the environment. In 14 simulations and 10 experiments, we consider the choice between strategies that operate on the accessibility of memories and those that depend on elaborate knowledge about the world. Based on Internet statistics, our model quantitatively predicts people's familiarity with and knowledge of real-world objects, the distributional characteristics of the associated speed of memory retrieval, and the cognitive niches of classic decision strategies, including those of the fluency, recognition, integration, lexicographic, and sequential-sampling heuristics. In doing so, the model specifies when people will be able to apply different strategies and how accurate, fast, and effortless people's decisions will be.

Early programming and late-acting checkpoints governing the development of CD4 T cell memory.

PubMed

Dhume, Kunal; McKinstry, K Kai

2018-04-27

CD4 T cells contribute to protection against pathogens through numerous mechanisms. Incorporating the goal of memory CD4 T cell generation into vaccine strategies thus offers a powerful approach to improve their efficacy, especially in situations where humoral responses alone cannot confer long-term immunity. These threats include viruses such as influenza that mutate coat proteins to avoid neutralizing antibodies, but that are targeted by T cells that recognize more conserved protein epitopes shared by different strains. A major barrier in the design of such vaccines is that the mechanisms controlling the efficiency with which memory cells form remain incompletely understood. Here, we discuss recent insights into fate decisions controlling memory generation. We focus on the importance of three general cues: interleukin-2, antigen, and costimulatory interactions. It is increasingly clear that these signals have a powerful influence on the capacity of CD4 T cells to form memory during two distinct phases of the immune response. First, through 'programming' that occurs during initial priming, and second, through 'checkpoints' that operate later during the effector stage. These findings indicate that novel vaccine strategies must seek to optimize cognate interactions, during which interleukin-2-, antigen, and costimulation-dependent signals are tightly linked, well beyond initial antigen encounter to induce robust memory CD4 T cells. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Categories, diversity, and relevance of memory strategies reported by community-dwelling seniors.

PubMed

Haché, Marie-Michèle; Lussier, Maxime; Parisien, Manon; Langlois, Francis; Bier, Nathalie

2018-01-01

Memory strategies help seniors remember information that is essential for the performance of their daily activities and contribute to their independence in the context of declining memory skills. This study aimed to analyze the categories, the diversity, and relevance of memory strategies known by seniors, and to identify individual characteristics that correlated with these variables. The sample consisted of 294 participants aged 60 and over who decided to take part in a cognitive vitality promotion program. An adapted version of the memory situation questionnaire (Troyer, 2001) was administered to identify the memory strategies that seniors would use in five daily life situations. A scoring grid, also adapted from the questionnaire's original version (Troyer, 2001), was used to quantify the relevance of the strategies that were reported by participants. All participants mentioned at least once that they would use a strategy from the physical category of memory strategies. Out of a possible range of 26 strategies, participants answered an average of 6.14 (SD = 1.7) different answers across the five situations. Based on expert consensus, 67.7% of the mentioned memory strategies were relevant. Diversity and relevance were significantly higher when trying to remember appointments, things to bring or phone numbers (p ≤ 0.05). The level of education, cognitive skills, and participation in leisure activities were related to diversity and relevance of reported strategies. Seniors know various and relevant memory strategies to perform daily activities. The advantages of integrating strategies that they already know in cognitive health promotion programs should be considered in further studies.

The effects of emotion regulation on explicit memory depend on strategy and testing method.

PubMed

Knight, Marisa; Ponzio, Allison

2013-12-01

Although previous work has shown that emotion regulation strategies can influence memory, the mechanisms through which different strategies produce different memory outcomes are not well understood. We examined how two cognitive reappraisal strategies with similar elaboration demands but diverging effects on visual attention and emotional arousal influenced explicit memory for emotional stimuli and for the strategies used to evaluate the stimuli. At encoding, participants used reappraisal to increase and decrease the personal relevance of neutral and emotional pictures. In two experiments, recall accuracy was highest for emotional pictures featured on increase trials, intermediate for emotional pictures featured on look (respond naturally) trials, and lowest for emotional pictures featured on decrease trials. This recall pattern emerged after a short delay (15 min) and persisted over a longer delay (48 hr). Memory accuracy for the strategies used to evaluate the pictures showed a different pattern: Strategy memory was better for emotional pictures featured on decrease and increase trials than for pictures featured on look trials. Our findings show that the effects of emotion regulation on memory depend both on the particular strategy engaged and the particular aspect of memory being tested.

Contributions of Feature Binding During Encoding and Functional Connectivity of the Medial Temporal Lobe Structures to Episodic Memory Deficits Across the Prodromal and First-Episode Phases of Schizophrenia

PubMed Central

Haut, Kristen M.; van Erp, Theo G. M.; Knowlton, Barbara; Bearden, Carrie E.; Subotnik, Kenneth; Ventura, Joseph; Nuechterlein, Keith H.; Cannon, Tyrone D.

2014-01-01

Patients with and at risk for psychosis may have difficulty using associative strategies to facilitate episodic memory encoding and recall. In parallel studies, patients with first-episode schizophrenia (n = 27) and high psychosis risk (n = 28) compared with control participants (n = 22 and n = 20, respectively) underwent functional MRI during a remember-know memory task. Psychophysiological interaction analyses, using medial temporal lobe (MTL) structures as regions of interest, were conducted to measure functional connectivity patterns supporting successful episodic memory. During encoding, patients with first-episode schizophrenia demonstrated reduced functional coupling between MTL regions and regions involved in stimulus representations, stimulus selection, and cognitive control. Relative to control participants and patients with high psychosis risk who did not convert to psychosis, patients with high psychosis risk who later converted to psychosis also demonstrated reduced connectivity between MTL regions and auditory-verbal and visual-association regions. These results suggest that episodic memory deficits in schizophrenia are related to inefficient recruitment of cortical connections involved in associative memory formation; such deficits precede the onset of psychosis among those individuals at high clinical risk. PMID:25750836

Contributions of Feature Binding During Encoding and Functional Connectivity of the Medial Temporal Lobe Structures to Episodic Memory Deficits Across the Prodromal and First-Episode Phases of Schizophrenia.

PubMed

Haut, Kristen M; van Erp, Theo G M; Knowlton, Barbara; Bearden, Carrie E; Subotnik, Kenneth; Ventura, Joseph; Nuechterlein, Keith H; Cannon, Tyrone D

2015-03-01

Patients with and at risk for psychosis may have difficulty using associative strategies to facilitate episodic memory encoding and recall. In parallel studies, patients with first-episode schizophrenia ( n = 27) and high psychosis risk ( n = 28) compared with control participants ( n = 22 and n = 20, respectively) underwent functional MRI during a remember-know memory task. Psychophysiological interaction analyses, using medial temporal lobe (MTL) structures as regions of interest, were conducted to measure functional connectivity patterns supporting successful episodic memory. During encoding, patients with first-episode schizophrenia demonstrated reduced functional coupling between MTL regions and regions involved in stimulus representations, stimulus selection, and cognitive control. Relative to control participants and patients with high psychosis risk who did not convert to psychosis, patients with high psychosis risk who later converted to psychosis also demonstrated reduced connectivity between MTL regions and auditory-verbal and visual-association regions. These results suggest that episodic memory deficits in schizophrenia are related to inefficient recruitment of cortical connections involved in associative memory formation; such deficits precede the onset of psychosis among those individuals at high clinical risk.

Use of memory strategies among younger and older adults: Results from objective and subjective measures.

PubMed

Fabricio, Aline Teixeira; Yassuda, Mônica Sanches

2011-01-01

Memory plays a fundamental role in the identity of people and in human life, as it enables us to interpret our surroundings and make decisions. It is known that the aging process can be accompanied by cognitive decline in some memory sub systems. However, the use of memory strategies can help encoding and retrieval of new information. The aim of this study was to identify and compare, using objective and subjective measures, which recall strategies are used spontaneously by young and older adults. Twenty-six first-year college students, and thirty-three seniors enrolled at the Third Age University of the same campus, completed a visual memory test including 18 black and white pictures, memorized a short story, and completed an open question about memory strategies, a memory check list to indicate strategies used, and a memory self-efficacy scale. The Bousfield categorization measure was also calculated from the recall protocol. Young adults demonstrated better performance than the older adults on the memory tasks, and were also more confident. Both groups reported using similar strategies. Young and older adults seem to tackle memory tasks in similar ways but young adults outperform seniors.

Aerobic fitness and executive control of relational memory in preadolescent children.

PubMed

Chaddock, Laura; Hillman, Charles H; Buck, Sarah M; Cohen, Neal J

2011-02-01

the neurocognitive benefits of an active lifestyle in childhood have public health and educational implications, especially as children in today's technological society are becoming increasingly overweight, unhealthy, and unfit. Human and animal studies show that aerobic exercise affects both prefrontal executive control and hippocampal function. This investigation attempts to bridge these research threads by using a cognitive task to examine the relationship between aerobic fitness and executive control of relational memory in preadolescent 9- and 10-yr-old children. higher-fit and lower-fit children studied faces and houses under individual item (i.e., nonrelational) and relational encoding conditions, and the children were subsequently tested with recognition memory trials consisting of previously studied pairs and pairs of completely new items. With each subject participating in both item and relational encoding conditions, and with recognition test trials amenable to the use of both item and relational memory cues, this task afforded a challenge to the flexible use of memory, specifically in the use of appropriate encoding and retrieval strategies. Hence, the task provided a test of both executive control and memory processes. lower-fit children showed poorer recognition memory performance than higher-fit children, selectively in the relational encoding condition. No association between aerobic fitness and recognition performance was found for faces and houses studied as individual items (i.e., nonrelationally). the findings implicate childhood aerobic fitness as a factor in the ability to use effective encoding and retrieval executive control processes for relational memory material and, possibly, in the strategic engagement of prefrontal- and hippocampal-dependent systems.

That's not funny! - But it should be: effects of humorous emotion regulation on emotional experience and memory.

PubMed

Kugler, Lisa; Kuhbandner, Christof

2015-01-01

Previous research has shown that humorous reappraisal can reduce elicited negative emotions, suggesting that humor may be a functional strategy to cope with emotionally negative situations. However, the effect of humorous reappraisal on later memory about the emotion-eliciting situation is currently unknown, although this is crucial for more adaptive responding in future situations. To address this issue, we examined the effects of humorous reappraisal on both emotional experience and memory, compared to non-humorous rational reappraisal and a non-reappraisal control condition. Replicating previous findings, humorous reappraisal reduced evoked negative valence and arousal levels very effectively, and the down-regulation of experienced negative emotions was even more pronounced after humorous compared to rational reappraisal. Regarding later memory for emotion-eliciting stimuli, both humorous and rational reappraisal reduced free recall, but recognition memory was unaffected, with memory strength being stronger after humorous than after rational reappraisal. These results indicate that humor seems to be indeed an optimal strategy to cope with negative situations because humor can help us to feel better when confronted with negative stimuli, but still allows us to retrieve stimulus information later when afforded to do so by the presence of appropriate contextual features.

Do older adults use the Method of Loci? Results from the ACTIVE Study

PubMed Central

Gross, Alden L.; Brandt, Jason; Bandeen-Roche, Karen; Carlson, Michelle C.; Stuart, Elizabeth A.; Marsiske, Michael; Rebok, George W.

2013-01-01

Background The method of loci (MoL) is a complex visuospatial mnemonic strategy. Previous research suggests older adults could potentially benefit from using the MoL, but that it is too attentionally demanding for them to use in practice. We evaluated the hypotheses that training can increase the use of MoL, and that MoL use is associated with better memory. Methods We analyzed skip patterns on response forms for the Auditory Verbal Learning Test (AVLT) in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE, n=1,401) trial using 5 years of longitudinal follow-up. Results At baseline, 2% of participants skipped spaces. Fewer than 2% of control participants skipped spaces at any visit across 5 years, but 25% of memory-trained participants, taught the MoL, did so. Participants who skipped spaces used more serial clustering, a hallmark of the MoL (p<0.001). Trained participants who skipped spaces showed greater memory improvement after training than memory-trained participants who did not skip spaces (Cohen's d=0.84, P=0.007), and did not differ in the subsequent rate of long-term memory decline through up to 5 years of follow-up. Conclusion Despite being attentionally demanding, this study suggests that after training, the MoL is used by up to 25% of older adults, and that its use is associated with immediate memory improvement that was sustained through the course of follow-up. Findings are consistent with the notion that older adults balance complexity with novelty in strategy selection, and that changes in strategies used following memory training result in observable qualitative and quantitative differences in memory performance. PMID:24625044

Strategies To Enhance Memory Based on Brain-Research.

ERIC Educational Resources Information Center

Banikowski, Alison K.; Mehring, Teresa A.

1999-01-01

This article reviews the literature on three aspects of memory: (1) an information processing model of memory (including the sensory register, attention, short-term memory, and long-term memory); (2) instructional strategies designed to enhance memory (which stress gaining students' attention and active involvement); and (3) reasons why…

Influence of emotional expression on memory recognition bias in schizophrenia as revealed by fMRI.

PubMed

Sergerie, Karine; Armony, Jorge L; Menear, Matthew; Sutton, Hazel; Lepage, Martin

2010-07-01

We recently showed that, in healthy individuals, emotional expression influences memory for faces both in terms of accuracy and, critically, in memory response bias (tendency to classify stimuli as previously seen or not, regardless of whether this was the case). Although schizophrenia has been shown to be associated with deficit in episodic memory and emotional processing, the relation between these processes in this population remains unclear. Here, we used our previously validated paradigm to directly investigate the modulation of emotion on memory recognition. Twenty patients with schizophrenia and matched healthy controls completed functional magnetic resonance imaging (fMRI) study of recognition memory of happy, sad, and neutral faces. Brain activity associated with the response bias was obtained by correlating this measure with the contrast subjective old (ie, hits and false alarms) minus subjective new (misses and correct rejections) for sad and happy expressions. Although patients exhibited an overall lower memory performance than controls, they showed the same effects of emotion on memory, both in terms of accuracy and bias. For sad faces, the similar behavioral pattern between groups was mirrored by a largely overlapping neural network, mostly involved in familiarity-based judgments (eg, parahippocampal gyrus). In contrast, controls activated a much larger set of regions for happy faces, including areas thought to underlie recollection-based memory retrieval (eg, superior frontal gyrus and hippocampus) and in novelty detection (eg, amygdala). This study demonstrates that, despite an overall lower memory accuracy, emotional memory is intact in schizophrenia, although emotion-specific differences in brain activation exist, possibly reflecting different strategies.

Control strategy based on SPWM switching patterns for grid connected photovoltaic inverter

NASA Astrophysics Data System (ADS)

Hassaine, L.; Mraoui, A.

2017-02-01

Generally, for lower installation of photovoltaic systems connected to the grid, pulse width modulation (PWM) is a widely used technique for controlling the voltage source inverters injects currents into the grid. The current injected must be sinusoidal with reduced harmonic distortion. In this paper, a digital implementation of a control strategy based on PWM switching patterns for an inverter for photovoltaic system connected to the grid is presented. This strategy synchronize a sinusoidal inverter output current with a grid voltage The digital implementation of the proposed PWM switching pattern when is compared with the conventional one exhibit the advantage: Simplicity, reduction of the memory requirements and power calculation for the control

Children's Memory for Words Under Self-Reported and Induced Imagery Strategies.

ERIC Educational Resources Information Center

Filan, Gary L.; Sullivan, Howard J.

The effectiveness of the use of self-reported imagery strategies on children's subsequent memory performance was studied, and the coding redundancy hypothesis that memory is facilitated by using an encoding procedure in both words and images was tested. The two levels of reported memory strategy (imagize, verbalize) were crossed with "think…

The Effects of Feedback on Memory Strategies of Younger and Older Adults

PubMed Central

Zhang, Fan; Zhang, Xin; Luo, Meng; Geng, Haiyan

2016-01-01

Existing literature suggests that feedback could effectively reduce false memories in younger adults. However, it is unclear whether memory performance in older adults also might be affected by feedback. The current study tested the hypothesis that older adults can use immediate feedback to adjust their memory strategy, similar to younger adults, but after feedback is removed, older adults may not be able to maintain using the memory strategy. Older adults will display more false memories than younger adults due to a reduction in attentional resources. In Study 1, both younger and older adults adjusted gist processing and item-specific processing biases based on the feedback given (i.e., biased and objective feedback). In Study 2 after the feedback was removed, only younger adults with full attention were able to maintain the feedback-shaped memory strategy; whereas, both younger adults with divided attention and older adults had increased false memories after feedback was removed. The findings suggest that environmental support helps older adults as well as younger adults to adopt a memory strategy that demands high attentional resources, but when the support is removed, older adults can no longer maintain such a strategy. PMID:28033327

The Effects of Feedback on Memory Strategies of Younger and Older Adults.

PubMed

Zhang, Fan; Zhang, Xin; Luo, Meng; Geng, Haiyan

2016-01-01

Existing literature suggests that feedback could effectively reduce false memories in younger adults. However, it is unclear whether memory performance in older adults also might be affected by feedback. The current study tested the hypothesis that older adults can use immediate feedback to adjust their memory strategy, similar to younger adults, but after feedback is removed, older adults may not be able to maintain using the memory strategy. Older adults will display more false memories than younger adults due to a reduction in attentional resources. In Study 1, both younger and older adults adjusted gist processing and item-specific processing biases based on the feedback given (i.e., biased and objective feedback). In Study 2 after the feedback was removed, only younger adults with full attention were able to maintain the feedback-shaped memory strategy; whereas, both younger adults with divided attention and older adults had increased false memories after feedback was removed. The findings suggest that environmental support helps older adults as well as younger adults to adopt a memory strategy that demands high attentional resources, but when the support is removed, older adults can no longer maintain such a strategy.

Strategy use fully mediates the relationship between working memory capacity and performance on Raven's matrices.

PubMed

Gonthier, Corentin; Thomassin, Noémylle

2015-10-01

Working memory capacity consistently correlates with fluid intelligence. It has been suggested that this relationship is partly attributable to strategy use: Participants with high working memory capacity would use more effective strategies, in turn leading to higher performance on fluid intelligence tasks. However, this idea has never been directly investigated. In 2 experiments, we tested this hypothesis by directly manipulating strategy use in a combined experimental-correlational approach (Experiment 1; N = 250) and by measuring strategy use with a self-report questionnaire (Experiment 2; N = 93). Inducing all participants to use an effective strategy in Raven's matrices decreased the correlation between working memory capacity and performance; the strategy use measure fully mediated the relationship between working memory capacity and performance on the matrices task. These findings indicate that individual differences in strategic behavior drive the predictive utility of working memory. We interpret the results within a theoretical framework integrating the multiple mediators of the relationship between working memory capacity and high-level cognition. (c) 2015 APA, all rights reserved).

Evidence-Based Practice for the Use of Internal Strategies as a Memory Compensation Technique After Brain Injury: A Systematic Review.

PubMed

OʼNeil-Pirozzi, Therese M; Kennedy, Mary R T; Sohlberg, McKay M

2016-01-01

To complete a systematic review of internal memory strategy use with people who have brain injury and provide practitioners with information that will impact their clinical work. A systematic literature search to identify published intervention studies that evaluated an internal memory strategy or technique to improve memory function of individuals with brain injury. Relevant data from reviewed articles were coded using 4 clinical questions targeting participants, interventions, research methods, and outcomes. A comprehensive search identified 130 study citations and abstracts. Forty-six met inclusion/exclusion criteria and were systematically reviewed. Visual imagery was most frequently studied, in isolation or in combination with other internal strategies. Despite significant variability in research methods and outcomes across studies, the evidence provides impetus for use of internal memory strategies with individuals following brain injury. Individuals with traumatic brain injury may benefit from internal memory strategy use, and clinicians should consider internal memory strategy instruction as part of intervention plans. Further research needs to better delineate influences on intervention candidacy and outcomes.

Short-Term and Working Memory Impairments in Early-Implanted, Long-Term Cochlear Implant Users Are Independent of Audibility and Speech Production

PubMed Central

AuBuchon, Angela M.; Pisoni, David B.; Kronenberger, William G.

2015-01-01

OBJECTIVES Determine if early-implanted, long-term cochlear implant (CI) users display delays in verbal short-term and working memory capacity when processes related to audibility and speech production are eliminated. DESIGN Twenty-three long-term CI users and 23 normal-hearing controls each completed forward and backward digit span tasks under testing conditions which differed in presentation modality (auditory or visual) and response output (spoken recall or manual pointing). RESULTS Normal-hearing controls reproduced more lists of digits than the CI users, even when the test items were presented visually and the responses were made manually via touchscreen response. CONCLUSIONS Short-term and working memory delays observed in CI users are not due to greater demands from peripheral sensory processes such as audibility or from overt speech-motor planning and response output organization. Instead, CI users are less efficient at encoding and maintaining phonological representations in verbal short-term memory utilizing phonological and linguistic strategies during memory tasks. PMID:26496666

Short-Term and Working Memory Impairments in Early-Implanted, Long-Term Cochlear Implant Users Are Independent of Audibility and Speech Production.

PubMed

AuBuchon, Angela M; Pisoni, David B; Kronenberger, William G

2015-01-01

To determine whether early-implanted, long-term cochlear implant (CI) users display delays in verbal short-term and working memory capacity when processes related to audibility and speech production are eliminated. Twenty-three long-term CI users and 23 normal-hearing controls each completed forward and backward digit span tasks under testing conditions that differed in presentation modality (auditory or visual) and response output (spoken recall or manual pointing). Normal-hearing controls reproduced more lists of digits than the CI users, even when the test items were presented visually and the responses were made manually via touchscreen response. Short-term and working memory delays observed in CI users are not due to greater demands from peripheral sensory processes such as audibility or from overt speech-motor planning and response output organization. Instead, CI users are less efficient at encoding and maintaining phonological representations in verbal short-term memory using phonological and linguistic strategies during memory tasks.

Low effective organizational strategies in visual memory performance of unmedicated alcoholics during early abstinence.

PubMed

Daig, Isolde; Mahlberg, Richard; Schroeder, Franziska; Gudlowski, Yehonala; Wrase, Jana; Wertenauer, Florian; Bschor, Tom; Esser, Guenter; Heinz, Andreas; Kienast, Thorsten

2010-12-14

Alcohol-dependent patients in early abstinence show an impairment of cognitive functions which can be seen in poor implementation of newly learned skills for avoiding relapse. Executive dysfunction may persist during abstinence in alcohol-dependent persons, thus mitigating long-term abstinence. This study assessed visual memory function and choice of organizational strategies in alcoholics, as these are major factors necessary to implement ongoing behavior changes which are required for maintaining abstinence. We investigated 25 severely alcohol-dependent male patients between days 7 to 10 of abstinence, immediately after clinical withdrawal symptoms have ceased, compared to 15 healthy age, sex, and education matched controls. Pharmacological therapy had been terminated at least four half-lifes before inclusion into the study. Visual perceptual learning and organizational strategies were assessed with the Rey-Osterrieth Complex Figure Test (R-OCF). There were no group differences in copying or recalling the figure, but time differences occurred. Alcoholics and healthy controls performed worse in recalling than in copying. But, alcoholics used less effective organizational strategies. There was a deficit in choice of organizational strategy in newly abstinent and unmedicated alcohol-dependent patients. Due to the imperfect organizational strategies, alcoholics might need auxiliary therapeutic care to strengthen their cognitive ability.

The effects of non-contingent extrinsic and intrinsic rewards on memory consolidation.

PubMed

Nielson, Kristy A; Bryant, Ted

2005-07-01

Emotional and arousing treatments given shortly after learning enhance delayed memory retrieval in animal and human studies. Positive affect and reward induced prior to a variety of cognitive tasks enhance performance, but their ability to affect memory consolidation has not been investigated before. Therefore, we investigated the effects of a small, non-contingent, intrinsic or extrinsic reward on delayed memory retrieval. Participants (n=108) studied and recalled a list of 30 affectively neutral, imageable nouns. Experimental groups were then given either an intrinsic reward (e.g., praise) or an extrinsic reward (e.g., US 1 dollar). After a one-week delay, participants' retrieval performance for the word list was significantly better in the extrinsic reward groups, whether the reward was expected or not, than in controls. Those who received the intrinsic reward performed somewhat better than controls, but the difference was not significant. Thus, at least some forms of arousal and reward, even when semantically unrelated to the learned material, can effectively modulate memory consolidation. These types of treatments might be useful for the development of new memory intervention strategies.

Neuroenhancement of Memory for Children with Autism by a Mind–Body Exercise

PubMed Central

Chan, Agnes S.; Han, Yvonne M. Y.; Sze, Sophia L.; Lau, Eliza M.

2015-01-01

The memory deficits found in individuals with autism spectrum disorder (ASD) may be caused by the lack of an effective strategy to aid memory. The executive control of memory processing is mediated largely by the timely coupling between frontal and posterior brain regions. The present study aimed to explore the potential effect of a Chinese mind–body exercise, namely Nei Gong, for enhancing learning and memory in children with ASD, and the possible neural basis of the improvement. Sixty-six children with ASD were randomly assigned to groups receiving Nei Gong training (NGT), progressive muscle relaxation (PMR) training, or no training for 1 month. Before and after training, the participants were tested individually on a computerized visual memory task while EEG signals were acquired during the memory encoding phase. Children in the NGT group demonstrated significantly enhanced memory performance and more effective use of a memory strategy, which was not observed in the other two groups. Furthermore, the improved memory after NGT was consistent with findings of elevated EEG theta coherence between frontal and posterior brain regions, a measure of functional coupling. The scalp EEG signals were localized by the standardized low resolution brain electromagnetic tomography method and found to originate from a neural network that promotes effective memory processing, including the prefrontal cortex, the parietal cortex, and the medial and inferior temporal cortex. This alteration in neural processing was not found in children receiving PMR or in those who received no training. The present findings suggest that the mind–body exercise program may have the potential effect on modulating neural functional connectivity underlying memory processing and hence enhance memory functions in individuals with autism. PMID:26696946

Neuroenhancement of Memory for Children with Autism by a Mind-Body Exercise.

PubMed

Chan, Agnes S; Han, Yvonne M Y; Sze, Sophia L; Lau, Eliza M

2015-01-01

The memory deficits found in individuals with autism spectrum disorder (ASD) may be caused by the lack of an effective strategy to aid memory. The executive control of memory processing is mediated largely by the timely coupling between frontal and posterior brain regions. The present study aimed to explore the potential effect of a Chinese mind-body exercise, namely Nei Gong, for enhancing learning and memory in children with ASD, and the possible neural basis of the improvement. Sixty-six children with ASD were randomly assigned to groups receiving Nei Gong training (NGT), progressive muscle relaxation (PMR) training, or no training for 1 month. Before and after training, the participants were tested individually on a computerized visual memory task while EEG signals were acquired during the memory encoding phase. Children in the NGT group demonstrated significantly enhanced memory performance and more effective use of a memory strategy, which was not observed in the other two groups. Furthermore, the improved memory after NGT was consistent with findings of elevated EEG theta coherence between frontal and posterior brain regions, a measure of functional coupling. The scalp EEG signals were localized by the standardized low resolution brain electromagnetic tomography method and found to originate from a neural network that promotes effective memory processing, including the prefrontal cortex, the parietal cortex, and the medial and inferior temporal cortex. This alteration in neural processing was not found in children receiving PMR or in those who received no training. The present findings suggest that the mind-body exercise program may have the potential effect on modulating neural functional connectivity underlying memory processing and hence enhance memory functions in individuals with autism.

The Source for Learning & Memory Strategies.

ERIC Educational Resources Information Center

Richards, Regina G.

This book is a comprehensive guide to learning and memory strategies for all students and especially those with learning problems. Chapter 1, on memory and the brain, explains brain cells, the cortex, function of the cerebral lobes, and other brain structures. Chapter 2 examines the memory process and discusses sensory memory, short-term memory,…

The Role of Cognitive Load in Intentional Forgetting Using the Think/No-Think Task.

PubMed

Noreen, Saima; de Fockert, Jan W

2017-01-01

We investigated the role of cognitive control in intentional forgetting by manipulating working memory load during the think/no-think task. In two experiments, participants learned a series of cue-target word pairs and were asked to recall the target words associated with some cues or to avoid thinking about the target associated with other cues. In addition to this, participants also performed a modified version of the n-back task which required them to respond to the identity of a single target letter present in the currently presented cue word (n = 0 condition, low working memory load), and in either the previous cue word (n = 1 condition, high working memory load, Experiment 1) or the cue word presented two trials previously (n = 2 condition, high working memory load, Experiment 2). Participants' memory for the target words was subsequently tested using same and novel independent probes. In both experiments it was found that although participants were successful at forgetting on both the same and independent-probe tests in the low working memory load condition, they were only successful at forgetting on the same-probe test in the high working memory load condition. We argue that our findings suggest that the high load working memory task diverted attention from direct suppression and acted as an interference-based strategy. Thus, when cognitive resources are limited participants can switch between the strategies they use to prevent unwanted memories from coming to mind.

The path to memory is guided by strategy: distinct networks are engaged in associative encoding under visual and verbal strategy and influence memory performance in healthy and impaired individuals

PubMed Central

Hales, J. B.; Brewer, J. B.

2018-01-01

Given the diversity of stimuli encountered in daily life, a variety of strategies must be used for learning new information. Relating and encoding visual and verbal stimuli into memory has been probed using various tasks and stimulus-types. Engagement of specific subsequent memory and cortical processing regions depends on the stimulus modality of studied material; however, it remains unclear whether different encoding strategies similarly influence regional activity when stimulus-type is held constant. In this study, subjects encoded object pairs using a visual or verbal associative strategy during functional magnetic resonance imaging (fMRI), and subsequent memory was assessed for pairs encoded under each strategy. Each strategy elicited distinct regional processing and subsequent memory effects: middle / superior frontal, lateral parietal, and lateral occipital for visually-associated pairs and inferior frontal, medial frontal, and medial occipital for verbally-associated pairs. This regional selectivity mimics the effects of stimulus modality, suggesting that cortical involvement in associative encoding is driven by strategy, and not simply by stimulus-type. The clinical relevance of these findings, probed in two patients with recent aphasic strokes, suggest that training with strategies utilizing unaffected cortical regions might improve memory ability in patients with brain damage. PMID:22390467

[Use of nondeclarative and automatic memory processes in motor learning: how to mitigate the effects of aging].

PubMed

Chauvel, Guillaume; Maquestiaux, François; Didierjean, André; Joubert, Sven; Dieudonné, Bénédicte; Verny, Marc

2011-12-01

Does normal aging inexorably lead to diminished motor learning abilities? This article provides an overview of the literature on the question, with particular emphasis on the functional dissociation between two sets of memory processes: declarative, effortful processes, and non-declarative, automatic processes. There is abundant evidence suggesting that aging does impair learning when past memories of former actions are required (episodic memory) and recollected through controlled processing (working memory). However, other studies have shown that aging does not impair learning when motor actions are performed non verbally and automatically (tapping procedural memory). These findings led us to hypothesize that one can minimize the impact of aging on the ability to learn new motor actions by favouring procedural learning. Recent data validating this hypothesis are presented. Our findings underline the importance of developing new motor learning strategies, which "bypass" declarative, effortful memory processes.

Intelligence moderates the benefits of strategy instructions on memory performance: an adult-lifespan examination.

PubMed

Frankenmolen, Nikita L; Altgassen, Mareike; Kessels, Renée; de Waal, Marleen M; Hindriksen, Julie-Anne; Verhoeven, Barbara; Fasotti, Luciano; Scheres, Anouk; Kessels, Roy P C; Oosterman, Joukje M

2017-01-01

Whether older adults can compensate for their associative memory deficit by using memory strategies efficiently might depend on their general cognitive abilities. This study examined the moderating role of an IQ estimate on the beneficial effects of strategy instructions. A total of 142 participants (aged 18-85 years) received either intentional learning or strategy ("sentence generation") instructions during encoding of word pairs. Whereas young adults with a lower IQ benefited from strategy instructions, those with a higher IQ did not, presumably because they already use strategies spontaneously. Older adults showed the opposite effect: following strategy instructions, older adults with a higher IQ showed a strong increase in memory performance (approximately achieving the level of younger adults), whereas older adults with a lower IQ did not, suggesting that they have difficulties implementing the provided strategies. These results highlight the importance of the role of IQ in compensating for the aging-related memory decline.

Cortical regions recruited for complex active-learning strategies and action planning exhibit rapid reactivation during memory retrieval.

PubMed

Voss, Joel L; Galvan, Ashley; Gonsalves, Brian D

2011-12-01

Memory retrieval can involve activity in the same sensory cortical regions involved in perception of the original event, and this neural "reactivation" has been suggested as an important mechanism of memory retrieval. However, it is still unclear if fragments of experience other than sensory information are retained and later reactivated during retrieval. For example, learning in non-laboratory settings generally involves active exploration of memoranda, thus requiring the generation of action plans for behavior and the use of strategies deployed to improve subsequent memory performance. Is information pertaining to action planning and strategic processing retained and reactivated during retrieval? To address this question, we compared ERP correlates of memory retrieval for objects that had been studied in an active manner involving action planning and strategic processing to those for objects that had been studied passively. Memory performance was superior for actively studied objects, and unique ERP retrieval correlates for these objects were identified when subjects remembered the specific spatial locations at which objects were studied. Early-onset frontal shifts in ERP correlates of retrieval were noted for these objects, which parallel the recruitment of frontal cortex during learning object locations previously identified using fMRI with the same paradigm. Notably, ERPs during recall for items studied with a specific viewing strategy localized to the same supplementary motor cortex region previously identified with fMRI when this strategy was implemented during study, suggesting rapid reactivation of regions directly involved in strategic action planning. Collectively, these results implicate neural populations involved in learning in important retrieval functions, even for those populations involved in strategic control and action planning. Notably, these episodic features are not generally reported during recollective experiences, suggesting that reactivation is a more general property of memory retrieval that extends beyond those fragments of perceptual information that might be needed to re-live the past. Copyright © 2011 Elsevier Ltd. All rights reserved.

Verbal Rehearsal and Memory in Children with Closed Head Injury: A Quantitative and Qualitative Analysis.

ERIC Educational Resources Information Center

Harris, Jessica R.

1996-01-01

Nine closed head injured (CHI) children (mean age 11 years) with post-onset intervals of 7 months to 8 years were given an overt free recall task. Quantitative analysis suggested inefficient passive rehearsal strategy by severely injured subjects. Qualitative analysis revealed differences between CHI children and controls in rehearsal strategies,…

Spatial Working Memory Ability in Individuals at Ultra High Risk for Psychosis

PubMed Central

Goghari, Vina M.; Brett, Caroline; Tabraham, Paul; Johns, Louise; Valmaggia, Lucia; Broome, Matthew; Woolley, James; Bramon, Elvira; Howes, Oliver

2014-01-01

The goal of this investigation was to clarify the nature of spatial working memory difficulties in individuals at ultra high risk (UHR) for psychosis. We evaluated spatial working memory and intelligence in 96 individuals at UHR for psychosis, 28 patients with first episode psychosis (FEP), and 23 healthy controls. Fourteen UHR individuals developed a psychotic disorder during follow-up. Compared to controls, the UHR group was impaired in both the short-term maintenance of material and in the effective use of strategy, but not more immediate memory. These impairments were not as severe as those in the FEP group, as the UHR group performed better than the FEP group. A similar pattern of results was found for the intelligence measures. Discriminant function analyses demonstrated short-term maintenance of material significantly differentiated the UHR and healthy control groups even when accounting for full scale intelligence quotient (IQ); whereas full scale IQ significantly differentiated the UHR and FEP groups and FEP and control groups. Notably, within the UHR group, impaired spatial working memory performance was associated with lower global functioning, but not full scale IQ. The subgroup of UHR individuals who later developed psychosis was not significantly more impaired on any aspect of working memory performance than the group of UHR individuals who did not develop psychosis. Given, the relationship between spatial working memory deficits and functional outcome, these results indicate that cognitive remediation could be useful in individuals at UHR for psychosis to potentially improve functioning. PMID:24398256

Can training in a real-time strategy video game attenuate cognitive decline in older adults?

PubMed

Basak, Chandramallika; Boot, Walter R; Voss, Michelle W; Kramer, Arthur F

2008-12-01

Declines in various cognitive abilities, particularly executive control functions, are observed in older adults. An important goal of cognitive training is to slow or reverse these age-related declines. However, opinion is divided in the literature regarding whether cognitive training can engender transfer to a variety of cognitive skills in older adults. In the current study, the authors trained older adults in a real-time strategy video game for 23.5 hr in an effort to improve their executive functions. A battery of cognitive tasks, including tasks of executive control and visuospatial skills, were assessed before, during, and after video-game training. The trainees improved significantly in the measures of game performance. They also improved significantly more than the control participants in executive control functions, such as task switching, working memory, visual short-term memory, and reasoning. Individual differences in changes in game performance were correlated with improvements in task switching. The study has implications for the enhancement of executive control processes of older adults. Copyright (c) 2009 APA, all rights reserved.

Interference from retrieval cues in Parkinson's disease.

PubMed

Crescentini, Cristiano; Marin, Dario; Del Missier, Fabio; Biasutti, Emanuele; Shallice, Tim

2011-11-01

Existing studies on memory interference in Parkinson's disease (PD) patients have provided mixed results and it is unknown whether PD patients have problems in overcoming interference from retrieval cues. We investigated this issue by using a part-list cuing paradigm. In this paradigm, after the study of a list of items, the presentation of some of these items as retrieval cues hinders the recall of the remaining ones. We tested PD patients' (n = 19) and control participants' (n = 16) episodic memory in the presence and absence of part-list cues, using initial-letter probes, and following either weak or strong serial associative encoding of list items. Both PD patients and control participants showed a comparable and significant part-list cuing effect after weak associative encoding (13% vs. 12% decrease in retrieval in part-list cuing vs. no part-list cuing -control- conditions in PD patients and control participants, respectively), denoting a similar effect of cue-driven interference in the two populations when a serial retrieval strategy is hard to develop. However, only PD patients showed a significant part-list cuing effect after strong associative encoding (20% vs. 5% decrease in retrieval in patients and controls, respectively). When encoding promotes the development of an effective serial retrieval strategy, the presentation of part-list cues has a specifically disruptive effect in PD patients. This indicates problems in strategic retrieval, probably related to PD patients' increased tendency to rely on external cues. Findings in control conditions suggest that less effective encoding may have contributed to PD patients' memory performance.

Coordination of size-control, reproduction and generational memory in freshwater planarians

NASA Astrophysics Data System (ADS)

Yang, Xingbo; Kaj, Kelson J.; Schwab, David J.; Collins, Eva-Maria S.

2017-06-01

Uncovering the mechanisms that control size, growth, and division rates of organisms reproducing through binary division means understanding basic principles of their life cycle. Recent work has focused on how division rates are regulated in bacteria and yeast, but this question has not yet been addressed in more complex, multicellular organisms. We have, over the course of several years, assembled a unique large-scale data set on the growth and asexual reproduction of two freshwater planarian species, Dugesia japonica and Girardia tigrina, which reproduce by transverse fission and succeeding regeneration of head and tail pieces into new planarians. We show that generation-dependent memory effects in planarian reproduction need to be taken into account to accurately capture the experimental data. To achieve this, we developed a new additive model that mixes multiple size control strategies based on planarian size, growth, and time between divisions. Our model quantifies the proportions of each strategy in the mixed dynamics, revealing the ability of the two planarian species to utilize different strategies in a coordinated manner for size control. Additionally, we found that head and tail offspring of both species employ different mechanisms to monitor and trigger their reproduction cycles. Thus, we find a diversity of strategies not only between species but between heads and tails within species. Our additive model provides two advantages over existing 2D models that fit a multivariable splitting rate function to the data for size control: firstly, it can be fit to relatively small data sets and can thus be applied to systems where available data is limited. Secondly, it enables new biological insights because it explicitly shows the contributions of different size control strategies for each offspring type.

Coordination of size-control, reproduction and generational memory in freshwater planarians.

PubMed

Yang, Xingbo; Kaj, Kelson J; Schwab, David J; Collins, Eva-Maria S

2017-05-23

Uncovering the mechanisms that control size, growth, and division rates of organisms reproducing through binary division means understanding basic principles of their life cycle. Recent work has focused on how division rates are regulated in bacteria and yeast, but this question has not yet been addressed in more complex, multicellular organisms. We have, over the course of several years, assembled a unique large-scale data set on the growth and asexual reproduction of two freshwater planarian species, Dugesia japonica and Girardia tigrina, which reproduce by transverse fission and succeeding regeneration of head and tail pieces into new planarians. We show that generation-dependent memory effects in planarian reproduction need to be taken into account to accurately capture the experimental data. To achieve this, we developed a new additive model that mixes multiple size control strategies based on planarian size, growth, and time between divisions. Our model quantifies the proportions of each strategy in the mixed dynamics, revealing the ability of the two planarian species to utilize different strategies in a coordinated manner for size control. Additionally, we found that head and tail offspring of both species employ different mechanisms to monitor and trigger their reproduction cycles. Thus, we find a diversity of strategies not only between species but between heads and tails within species. Our additive model provides two advantages over existing 2D models that fit a multivariable splitting rate function to the data for size control: firstly, it can be fit to relatively small data sets and can thus be applied to systems where available data is limited. Secondly, it enables new biological insights because it explicitly shows the contributions of different size control strategies for each offspring type.

Autobiographical memory specificity in dissociative identity disorder.

PubMed

Huntjens, Rafaële J C; Wessel, Ineke; Hermans, Dirk; van Minnen, Agnes

2014-05-01

A lack of adequate access to autobiographical knowledge has been related to psychopathology. More specifically, patients suffering from depression or a history of trauma have been found to be characterized by overgeneral memory, in other words, they show a relative difficulty in retrieving a specific event from memory located in time and place. Previous studies of overgeneral memory have not included patients with dissociative disorders. These patients are interesting to consider, as they are hypothesized to have the ability to selectively compartmentalize information linked to negative emotions. This study examined avoidance and overgeneral memory in patients with dissociative identity disorder (DID; n = 12). The patients completed the autobiographical memory test (AMT). Their performance was compared with control groups of posttraumatic stress disorder (PTSD) patients (n = 26), healthy controls (n = 29), and DID simulators (n = 26). Specifically, we compared the performance of separate identity states in DID hypothesized to diverge in the use of avoidance as a coping strategy to deal with negative affect. No significant differences in memory specificity were found between the separate identities in DID. Irrespective of identity state, DID patients were characterized by a lack of memory specificity, which was similar to the lack of memory specificity found in PTSD patients. The converging results for DID and PTSD patients add empirical evidence for the role of overgeneral memory involved in the maintenance of posttraumatic psychopathology.

[Effects of Ginkgo biloba extract in improving episodic memory of patients with mild cognitive impairment: a randomized controlled trial].

PubMed

Zhao, Ming-xing; Dong, Zhen-hua; Yu, Zhong-hai; Xiao, Shi-yuan; Li, Ya-ming

2012-06-01

Mild cognitive impairment is a transitional stage between normal aging and dementia. It is important in terms of recognizing memory loss in older people as well as identifying a group of individuals at high risk of developing dementia and who may benefit from preventive strategies. Ginkgo biloba extract has been shown to possess polyvalent properties, such as anti-oxidation, anti-apoptosis and anti-inflammation. Ginkgo biloba extract appears to have a neuroprotective effect against neurodegenerative diseases. To observe the efficacy of Ginkgo biloba leaf tablet in improving episodic memory of mild cognitive impairment. This is a multicenter, randomized, controlled trial. The authors enrolled generally healthy, ambulatory or ambulatory-aided amnestic subjects with MCI, 60 to 85 years old, who expressed a memory complaint from Huadong Hospital, seven Community Health Centers in Shanghai, and Shanghai First Welfare Institution. A total of 120 MCI patients were randomly assigned to the Ginkgo biloba leaf tablet group (treatment group, 60 cases) and control group (60 cases). The patients in the treatment group took Ginkgo biloba leaf tablets 3 times a day, 19.2 mg each dose. The control group did not receive any intelligence-promoting or vasodilator reflex treatment except some health care. The patients were tested with nonsense picture recognition of the clinical memory scale and the logical memory test based on the Wechsler memory scale before and after treatment. After 6 months of treatment, the scores of the logical memory test and nonsense picture recognition were increased significantly in the treatment group (P<0.01, P<0.05), while the scores of the two tests from the control group had no statistically significant difference (P>0.05). After treatment, the positive rate of nonsense picture recognition was 55.17% in the treatment group, which was significantly higher than that of the control group at 32.73% (P<0.05). The efficacy rate of logical memory was 58.62% in the treatment group, also higher than 38.18% in the control group (P<0.05). Ginkgo biloba leaf tablet showed good efficacy in promoting episodic memory function in MCI patients.

Improving the effectiveness of an interruption lag by inducing a memory-based strategy.

PubMed

Morgan, Phillip L; Patrick, John; Tiley, Leyanne

2013-01-01

The memory for goals model (Altmann & Trafton, 2002) posits the importance of a short delay (the 'interruption lag') before an interrupting task to encode suspended goals for retrieval post-interruption. Two experiments used the theory of soft constraints (Gray, Simms, Fu & Schoelles, 2006) to investigate whether the efficacy of an interruption lag could be improved by increasing goal-state access cost to induce a more memory-based encoding strategy. Both experiments used a copying task with three access cost conditions (Low, Medium, and High) and a 5-s interruption lag with a no lag control condition. Experiment 1 found that the participants in the High access cost condition resumed more interrupted trials and executed more actions correctly from memory when coupled with an interruption lag. Experiment 2 used a prospective memory test post-interruption and an eyetracker recorded gaze activity during the interruption lag. The participants in the High access cost condition with an interruption lag were best at encoding target information during the interruption lag, evidenced by higher scores on the prospective memory measure and more gaze activity on the goal-state during the interruption lag. Theoretical and practical issues regarding the use of goal-state access cost and an interruption lag are discussed. Copyright © 2012. Published by Elsevier B.V.

That’s not funny! – But it should be: effects of humorous emotion regulation on emotional experience and memory

PubMed Central

Kugler, Lisa; Kuhbandner, Christof

2015-01-01

Previous research has shown that humorous reappraisal can reduce elicited negative emotions, suggesting that humor may be a functional strategy to cope with emotionally negative situations. However, the effect of humorous reappraisal on later memory about the emotion-eliciting situation is currently unknown, although this is crucial for more adaptive responding in future situations. To address this issue, we examined the effects of humorous reappraisal on both emotional experience and memory, compared to non-humorous rational reappraisal and a non-reappraisal control condition. Replicating previous findings, humorous reappraisal reduced evoked negative valence and arousal levels very effectively, and the down-regulation of experienced negative emotions was even more pronounced after humorous compared to rational reappraisal. Regarding later memory for emotion-eliciting stimuli, both humorous and rational reappraisal reduced free recall, but recognition memory was unaffected, with memory strength being stronger after humorous than after rational reappraisal. These results indicate that humor seems to be indeed an optimal strategy to cope with negative situations because humor can help us to feel better when confronted with negative stimuli, but still allows us to retrieve stimulus information later when afforded to do so by the presence of appropriate contextual features. PMID:26379608

Learning and memory in disease vector insects

PubMed Central

Vinauger, Clément; Lahondère, Chloé; Cohuet, Anna; Lazzari, Claudio R.; Riffell, Jeffrey A.

2016-01-01

Learning and memory plays an important role in host preference and parasite transmission by disease vector insects. Historically there has been a dearth of standardized protocols that permit testing their learning abilities, thus limiting discussion on the potential epidemiological consequences of learning and memory to a largely speculative extent. However, with increasing evidence that individual experience and associative learning can affect processes such as oviposition site selection and host preference, it is timely to review the recently acquired knowledge, identify research gaps and discuss the implication of learning in disease vector insects in perspective with control strategies. PMID:27450224

Working Memory Maturation: Can We Get at the Essence of Cognitive Growth?

PubMed

Cowan, Nelson

2016-03-01

The theoretical and practical understanding of cognitive development depends on working memory, the limited information temporarily accessible for such daily activities as language processing and problem solving. In this article, I assess many possible reasons that working memory performance improves with development. A first glance at the literature leads to the weird impression that working memory capacity reaches adult levels during infancy but then regresses during childhood. In place of that unlikely explanation, I consider how infant studies may lead to overestimates of capacity if one neglects supports that the tasks provide, compared with adult-level tasks. Further development of working memory during the school years is also considered. Many investigators have come to suspect that working memory capacity may be constant after infancy because of various factors such as developmental increases in knowledge, filtering out of irrelevant distractions, encoding and rehearsal strategies, and pattern formation. With each of these factors controlled, though, working memory still improves during the school years. Suggestions are made for research to bridge the gap between infant and child developmental research, to understand the focus and control of attention in working memory and how these skills develop, and to pinpoint the nature of capacity and its development from infancy forward. © The Author(s) 2016.

Working Memory Maturation: Can We Get At the Essence of Cognitive Growth?

PubMed Central

Cowan, Nelson

2015-01-01

Our theoretical and practical understanding of cognitive development depends on working memory, the limited information temporarily accessible for such daily activities as language processing and problem-solving. Here I assess many possible reasons why working memory performance improves with development. A first glance at the literature leads to the weird impression that working memory capacity reaches adult-like levels during infancy but then regresses during childhood. In place of that unlikely surmise, I consider how infant studies may lead to overestimates of capacity if one neglects supports that the tasks provide, compared to adult-like tasks. Further development of working memory during the school years is also considered. Various confounding factors have led many investigators to suspect that working memory capacity may be constant after infancy; the factors include developmental increases in knowledge, filtering out of irrelevant distractions, encoding and rehearsal strategies, and pattern formation. With each of these factors controlled, though, working memory still improves during the school years. Suggestions are made for research to bridge the gap between infant and child developmental research, to understand the focus and control of attention in working memory and how they develop, and to pinpoint the nature of capacity and its development from infancy on. PMID:26993277

The Development of Young Children's Memory Strategies: First Findings from the Wurzburg Longitudinal Memory Study

ERIC Educational Resources Information Center

Schneider, Wolfgang; Kron, Veronika; Hunnerkopf, Michael; Krajewski, Kristin

2004-01-01

This article reports the first findings of the Wurzburg Longitudinal Memory Study, which focuses on children's verbal memory development, particularly the acquisition of memory strategies. At the beginning of the study, 100 kindergarten children (mean age 6-and-1/2 years) were tested on various memory measures, including sort--recall, text recall,…

Prospective memory impairments in heavy social drinkers are partially overcome by future event simulation.

PubMed

Platt, Bradley; Kamboj, Sunjeev K; Italiano, Tommaso; Rendell, Peter G; Curran, H Valerie

2016-02-01

Recent research suggests that alcohol acutely impairs prospective memory (PM), and this impairment can be overcome using a strategy called 'future event simulation' (FES). Impairment in event-based PM found in detoxifying alcohol-dependent participants is reversed through FES. However, the impact of the most common problematic drinking patterns that do not involve alcohol dependence on PM remains unclear. Here, we examine the impact of frequent heavy drinking on PM and the degree to which any impairments can be reversed through FES. PM was assessed in 19 heavy drinkers (AUDIT scores ≥ 15) and 18 matched control participants (AUDIT scores ≤ 7) using the 'Virtual Week' task both at baseline and again following FES. Heavy drinkers performed significantly worse than controls on regular and irregular time-based PM tasks. FES improved the performance of controls but not of heavy drinkers on time-based tasks. In contrast, FES improved heavy drinkers' performance on event-based PM tasks. These findings suggest that heavy drinkers experience deficits in strategic monitoring processing associated with time-based PM tasks which do not abate after FES. That the same strategy improves their event-based PM suggests that FES may be helpful for individuals with problematic drinking patterns in improving their prospective memory.

A robust preference for cheap-and-easy strategies over reliable strategies when verifying personal memories.

PubMed

Nash, Robert A; Wade, Kimberley A; Garry, Maryanne; Adelman, James S

2017-08-01

People depend on various sources of information when trying to verify their autobiographical memories. Yet recent research shows that people prefer to use cheap-and-easy verification strategies, even when these strategies are not reliable. We examined the robustness of this cheap strategy bias, with scenarios designed to encourage greater emphasis on source reliability. In three experiments, subjects described real (Experiments 1 and 2) or hypothetical (Experiment 3) autobiographical events, and proposed strategies they might use to verify their memories of those events. Subjects also rated the reliability, cost, and the likelihood that they would use each strategy. In line with previous work, we found that the preference for cheap information held when people described how they would verify childhood or recent memories (Experiment 1), personally important or trivial memories (Experiment 2), and even when the consequences of relying on incorrect information could be significant (Experiment 3). Taken together, our findings fit with an account of source monitoring in which the tendency to trust one's own autobiographical memories can discourage people from systematically testing or accepting strong disconfirmatory evidence.

Is evaluative conditioning really uncontrollable? A comparative test of three emotion-focused strategies to prevent the acquisition of conditioned preferences.

PubMed

Gawronski, Bertram; Mitchell, Derek G V; Balas, Robert

2015-10-01

Evaluative conditioning (EC) is defined as the change in the evaluation of a conditioned stimulus (CS) because of its pairing with a valenced unconditioned stimulus (US). Counter to views that EC is the product of automatic learning processes, recent research has revealed various characteristics of nonautomatic processing in EC. The current research investigated the controllability of EC by testing the effectiveness of 3 emotion-focused strategies in preventing the acquisition of conditioned preferences: (a) suppression of emotional reactions to the US, (b) reappraisal of the valence of the US, and (c) facial blocking of emotional responses. Although all 3 strategies reduced EC effects on self-reported evaluations by impairing recollective memory for CS-US pairings, they were ineffective in reducing EC effects on an evaluative priming measure. Regardless of the measure, effective control did not depend on the level of arousal elicited by the US. The results suggest that the 3 strategies can influence deliberate CS evaluations through memory-related processes, but they are ineffective in reducing EC effects on spontaneous evaluative responses. Implications for mental process theories of EC are discussed. (c) 2015 APA, all rights reserved).

Cognitive Strategies and Physical Activity in Older Adults: A Discriminant Analysis

PubMed Central

Ferrand, Claude; Audiffren, Michel

2018-01-01

Background Although a number of studies have examined sociodemographic, psychosocial, and environmental determinants of the level of physical activity (PA) for older people, little attention has been paid to the predictive power of cognitive strategies for independently living older adults. However, cognitive strategies have recently been considered to be critical in the management of day-to-day living. Methods Data were collected from 243 men and women aged 55 years and older living in France using face-to-face interviews between 2011 and 2013. Results A stepwise discriminant analysis selected five predictor variables (age, perceived health status, barriers' self-efficacy, internal memory, and attentional control strategies) of the level of PA. The function showed that the rate of correct prediction was 73% for the level of PA. The calculated discriminant function based on the five predictor variables is useful for detecting individuals at high risk of lapses once engaged in regular PA. Conclusions This study highlighted the need to consider cognitive functions as a determinant of the level of PA and, more specifically, those cognitive functions related to executive functions (internal memory and attentional control), to facilitate the maintenance of regular PA. These results are discussed in relation to successful aging. PMID:29850247

Cognitive Strategies and Physical Activity in Older Adults: A Discriminant Analysis.

PubMed

André, Nathalie; Ferrand, Claude; Albinet, Cédric; Audiffren, Michel

2018-01-01

Although a number of studies have examined sociodemographic, psychosocial, and environmental determinants of the level of physical activity (PA) for older people, little attention has been paid to the predictive power of cognitive strategies for independently living older adults. However, cognitive strategies have recently been considered to be critical in the management of day-to-day living. Data were collected from 243 men and women aged 55 years and older living in France using face-to-face interviews between 2011 and 2013. A stepwise discriminant analysis selected five predictor variables (age, perceived health status, barriers' self-efficacy, internal memory, and attentional control strategies) of the level of PA. The function showed that the rate of correct prediction was 73% for the level of PA. The calculated discriminant function based on the five predictor variables is useful for detecting individuals at high risk of lapses once engaged in regular PA. This study highlighted the need to consider cognitive functions as a determinant of the level of PA and, more specifically, those cognitive functions related to executive functions (internal memory and attentional control), to facilitate the maintenance of regular PA. These results are discussed in relation to successful aging.

Making Memories Matter

PubMed Central

Gold, Paul E.; Korol, Donna L.

2012-01-01

This article reviews some of the neuroendocrine bases by which emotional events regulate brain mechanisms of learning and memory. In laboratory rodents, there is extensive evidence that epinephrine influences memory processing through an inverted-U relationship, at which moderate levels enhance and high levels impair memory. These effects are, in large part, mediated by increases in blood glucose levels subsequent to epinephrine release, which then provide support for the brain processes engaged by learning and memory. These brain processes include augmentation of neurotransmitter release and of energy metabolism, the latter apparently including a key role for astrocytic glycogen. In addition to up- and down-regulation of learning and memory in general, physiological concomitants of emotion and arousal can also switch the neural system that controls learning at a particular time, at once improving some attributes of learning and impairing others in a manner that results in a change in the strategy used to solve a problem. PMID:23264764

An improved car-following model considering headway changes with memory

NASA Astrophysics Data System (ADS)

Yu, Shaowei; Shi, Zhongke

2015-03-01

To describe car-following behaviors in complex situations better, increase roadway traffic mobility and minimize cars' fuel consumptions, the linkage between headway changes with memory and car-following behaviors was explored with the field car-following data by using the gray correlation analysis method, and then an improved car-following model considering headway changes with memory on a single lane was proposed based on the full velocity difference model. Some numerical simulations were carried out by employing the improved car-following model to explore how headway changes with memory affected each car's velocity, acceleration, headway and fuel consumptions. The research results show that headway changes with memory have significant effects on car-following behaviors and fuel consumptions and that considering headway changes with memory in designing the adaptive cruise control strategy can improve the traffic flow stability and minimize cars' fuel consumptions.

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

Retrieval practice as an effective memory strategy in children and adolescents with traumatic brain injury.

PubMed

Coyne, Julia H; Borg, Jacquelyn M; DeLuca, John; Glass, Leslie; Sumowski, James F

2015-04-01

To investigate whether retrieval practice (RP) is a more effective memory strategy than restudy in children and adolescents with traumatic brain injury (TBI). Three × two within-subjects experiment: 3 (learning condition: massed restudy [MR], spaced restudy [SR], retrieval practice [RP]) × 2 (stimulus type: verbal paired associates [VPAs] and face-name pairs [FNPs]). The dependent measure was delayed recall of VPAs and FNPs. Subacute pediatric neurorehabilitation center. Pediatric survivors of TBI (N=15) aged 8 to 16 years with below-average memory. During RP, participants were quizzed on to-be-learned information (VPAs and FNPs) shortly after it was presented, such that they practiced retrieval during the learning phase. MR consisted of repeated restudy (tantamount to cramming). SR consisted of restudy trials separated in time (ie, distributed learning). Delayed recall of 24 VPAs and 24 FNPs after a 25-minute delay. VPAs and FNPs were equally divided across 3 learning conditions (16 per condition). There was a large main effect of learning condition on delayed recall (P<.001; ηp(2)=.84), with better mean recall of VPAs and FNPs studied through RP (6.23±1.39) relative to MR (3.60±1.53; P<.001) and SR (4.77±1.39; P<.001). Moreover, RP was the single best learning strategy for every participant. Memory problems and related academic learning difficulties are common after pediatric TBI. Herein, we identify RP as a promising and simple strategy to support learning and improve memory in children and adolescents with TBI. Our experimental findings were quite robust and set the stage for subsequent randomized controlled trials of RP in pediatric TBI. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Mnemonic strategies in older people: a comparison of errorless and errorful learning.

PubMed

Kessels, Roy P C; de Haan, Edward H F

2003-09-01

To compare the efficacy of errorless and errorful learning on memory performance in older people and young adults. Face-name association learning was examined in 18 older people and 16 young controls. Subjects were either prompted to guess the correct name during the presentation of photographs of unknown faces (errorful learning) or were instructed to study the face without guessing (errorless learning). The correct name was given after the presentation of each face in both task conditions. Uncued testing followed immediately after the two study phases and after a 10-minute delay. Older subjects had an overall lower memory performance and flatter learning curves compared to the young adults, regardless of task conditions. Also, errorless learning resulted in a higher accuracy than errorful learning, to an equal amount in both groups. Older people have difficulty in the encoding stages of face-name association learning, whereas retrieval is relatively unaffected. In addition, the prevention of errors occurring during learning results in a better memory performance, and is perhaps an effective strategy for coping with age-related memory decrement.

The influence of an auditory-memory attention-demanding task on postural control in blind persons.

PubMed

Melzer, Itshak; Damry, Elad; Landau, Anat; Yagev, Ronit

2011-05-01

In order to evaluate the effect of an auditory-memory attention-demanding task on balance control, nine blind adults were compared to nine age-gender-matched sighted controls. This issue is particularly relevant for the blind population in which functional assessment of postural control has to be revealed through "real life" motor and cognitive function. The study aimed to explore whether an auditory-memory attention-demanding cognitive task would influence postural control in blind persons and compare this with blindfolded sighted persons. Subjects were instructed to minimize body sway during narrow base upright standing on a single force platform under two conditions: 1) standing still (single task); 2) as in 1) while performing an auditory-memory attention-demanding cognitive task (dual task). Subjects in both groups were required to stand blindfolded with their eyes closed. Center of Pressure displacement data were collected and analyzed using summary statistics and stabilogram-diffusion analysis. Blind and sighted subjects had similar postural sway in eyes closed condition. However, for dual compared to single task, sighted subjects show significant decrease in postural sway while blind subjects did not. The auditory-memory attention-demanding cognitive task had no interference effect on balance control on blind subjects. It seems that sighted individuals used auditory cues to compensate for momentary loss of vision, whereas blind subjects did not. This may suggest that blind and sighted people use different sensorimotor strategies to achieve stability. Copyright © 2010 Elsevier Ltd. All rights reserved.

Predictive Coding Strategies for Invariant Object Recognition and Volitional Motion Control in Neuromorphic Agents

DTIC Science & Technology

2015-09-02

human behavior. In this project, we hypothesized that visual memory of past motion trajectories may be used for selecting future behavior. In other...34Decoding sequence of actions using fMRI ", Society for Neuroscience Annual Meeting, San Diego, CA, USA, Nov 9-13 2013 (only abstract) 3. Hansol Choi, Dae...Shik Kim, "Planning as inference in a Hierarchical Predictive Memory ", Proceedings of International Conference on Neural Information Processing

Dissociating the effects of semantic grouping and rehearsal strategies on event-related brain potentials.

PubMed

Schleepen, T M J; Markus, C R; Jonkman, L M

2014-12-01

The application of elaborative encoding strategies during learning, such as grouping items on similar semantic categories, increases the likelihood of later recall. Previous studies have suggested that stimuli that encourage semantic grouping strategies had modulating effects on specific ERP components. However, these studies did not differentiate between ERP activation patterns evoked by elaborative working memory strategies like semantic grouping and more simple strategies like rote rehearsal. Identification of neurocognitive correlates underlying successful use of elaborative strategies is important to understand better why certain populations, like children or elderly people, have problems applying such strategies. To compare ERP activation during the application of elaborative versus more simple strategies subjects had to encode either four semantically related or unrelated pictures by respectively applying a semantic category grouping or a simple rehearsal strategy. Another goal was to investigate if maintenance of semantically grouped vs. ungrouped pictures modulated ERP-slow waves differently. At the behavioral level there was only a semantic grouping benefit in terms of faster responding on correct rejections (i.e. when the memory probe stimulus was not part of the memory set). At the neural level, during encoding semantic grouping only had a modest specific modulatory effect on a fronto-central Late Positive Component (LPC), emerging around 650 ms. Other ERP components (i.e. P200, N400 and a second Late Positive Component) that had been earlier related to semantic grouping encoding processes now showed stronger modulation by rehearsal than by semantic grouping. During maintenance semantic grouping had specific modulatory effects on left and right frontal slow wave activity. These results stress the importance of careful control of strategy use when investigating the neural correlates of elaborative encoding. Copyright © 2014 Elsevier B.V. All rights reserved.

Extracellular matrix controls neuronal features that mediate the persistence of fear.

PubMed

Pignataro, Annabella; Pagano, Roberto; Guarneri, Giorgia; Middei, Silvia; Ammassari-Teule, Martine

2017-12-01

Degradation of the chondroitin sulfate proteoglycans of the extracellular matrix (ECM) by injections of the bacterial enzyme chondroitinase ABC (ChABC) in the basolateral amygdala (BLA) does not impair fear memory formation but accelerates its extinction and disrupts its reactivation. These observations suggest that the treatment might selectively interfere with the post-extinction features of neurons that mediate the reinstatement of fear. Here, we report that ChABC mice show regular fear memory and memory-driven c-fos activation and dendritic spine formation in the BLA. These mice then rapidly extinguish their fear response and exhibit a post-extinction concurrent reduction in c-fos activation and large dendritic spines that extends to the anterior cingulate cortex 7 days later. At this remote time point, fear renewal and fear retrieval are impaired. These findings show that a non-cellular component of the brain tissue controls post-extinction levels of neuronal activity and spine enlargement in the regions sequentially remodelled during the formation of recent and remote fear memory. By preventing BLA and aCC neurons to retain neuronal features that serve to reactivate an extinguished fear memory, ECM digestion might offer a therapeutic strategy for durable attenuation of traumatic memories.

Brownmillerite thin films as fast ion conductors for ultimate-performance resistance switching memory.

PubMed

Acharya, Susant Kumar; Jo, Janghyun; Raveendra, Nallagatlla Venkata; Dash, Umasankar; Kim, Miyoung; Baik, Hionsuck; Lee, Sangik; Park, Bae Ho; Lee, Jae Sung; Chae, Seung Chul; Hwang, Cheol Seong; Jung, Chang Uk

2017-07-27

An oxide-based resistance memory is a leading candidate to replace Si-based flash memory as it meets the emerging specifications for future memory devices. The non-uniformity in the key switching parameters and low endurance in conventional resistance memory devices are preventing its practical application. Here, a novel strategy to overcome the aforementioned challenges has been unveiled by tuning the growth direction of epitaxial brownmillerite SrFeO 2.5 thin films along the SrTiO 3 [111] direction so that the oxygen vacancy channels can connect both the top and bottom electrodes rather directly. The controlled oxygen vacancy channels help reduce the randomness of the conducting filament (CF). The resulting device displayed high endurance over 10 6 cycles, and a short switching time of ∼10 ns. In addition, the device showed very high uniformity in the key switching parameters for device-to-device and within a device. This work demonstrates a feasible example for improving the nanoscale device performance by controlling the atomic structure of a functional oxide layer.

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.

What–where–when memory and encoding strategies in healthy aging

PubMed Central

2016-01-01

Older adults exhibit disproportionate impairments in memory for item-associations. These impairments may stem from an inability to self-initiate deep encoding strategies. The present study investigates this using the “treasure-hunt task”; a what–where–when style episodic memory test that requires individuals to “hide” items around complex scenes. This task separately assesses memory for item, location, and temporal order, as well as bound what–where–when information. The results suggest that older adults are able to ameliorate integration memory deficits by using self-initiated encoding strategies when these are externally located and therefore place reduced demands on working memory and attentional resources. PMID:26884230

Theta oscillations during holeboard training in rats: different learning strategies entail different context-dependent modulations in the hippocampus.

PubMed

Woldeit, M L; Korz, V

2010-02-03

A functional connection between theta rhythms, information processing, learning and memory formation is well documented by studies focusing on the impact of theta waves on motor activity, global context or phase coding in spatial learning. In the present study we analyzed theta oscillations during a spatial learning task and assessed which specific behavioral contexts were connected to changes in theta power and to the formation of memory. Therefore, we measured hippocampal dentate gyrus theta modulations in male rats that were allowed to establish a long-term spatial reference memory in a holeboard (fixed pattern of baited holes) in comparison to rats that underwent similar training conditions but could not form a reference memory (randomly baited holes). The first group established a pattern specific learning strategy, while the second developed an arbitrary search strategy, visiting increasingly more holes during training. Theta power was equally influenced during the training course in both groups, but was significantly higher when compared to untrained controls. A detailed behavioral analysis, however, revealed behavior- and context-specific differences within the experimental groups. In spatially trained animals theta power correlated with the amounts of reference memory errors in the context of the inspection of unbaited holes and exploration in which, as suggested by time frequency analyses, also slow wave (delta) power was increased. In contrast, in randomly trained animals positive correlations with working memory errors were found in the context of rearing behavior. These findings indicate a contribution of theta/delta to long-lasting memory formation in spatially trained animals, whereas in pseudo trained animals theta seems to be related to attention in order to establish trial specific short-term working memory. Implications for differences in neuronal plasticity found in earlier studies are discussed. Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Small groups and long memories promote cooperation.

PubMed

Stewart, Alexander J; Plotkin, Joshua B

2016-06-01

Complex social behaviors lie at the heart of many of the challenges facing evolutionary biology, sociology, economics, and beyond. For evolutionary biologists the question is often how group behaviors such as collective action, or decision making that accounts for memories of past experience, can emerge and persist in an evolving system. Evolutionary game theory provides a framework for formalizing these questions and admitting them to rigorous study. Here we develop such a framework to study the evolution of sustained collective action in multi-player public-goods games, in which players have arbitrarily long memories of prior rounds of play and can react to their experience in an arbitrary way. We construct a coordinate system for memory-m strategies in iterated n-player games that permits us to characterize all cooperative strategies that resist invasion by any mutant strategy, and stabilize cooperative behavior. We show that, especially when groups are small, longer-memory strategies make cooperation easier to evolve, by increasing the number of ways to stabilize cooperation. We also explore the co-evolution of behavior and memory. We find that even when memory has a cost, longer-memory strategies often evolve, which in turn drives the evolution of cooperation, even when the benefits for cooperation are low.

Executive Functions Are Employed to Process Episodic and Relational Memories in Children With Autism Spectrum Disorders

PubMed Central

2013-01-01

Objective: Long-term memory functioning in autism spectrum disorders (ASDs) is marked by a characteristic pattern of impairments and strengths. Individuals with ASD show impairment in memory tasks that require the processing of relational and contextual information, but spared performance on tasks requiring more item-based, acontextual processing. Two experiments investigated the cognitive mechanisms underlying this memory profile. Method: A sample of 14 children with a diagnosis of high-functioning ASD (age: M = 12.2 years), and a matched control group of 14 typically developing (TD) children (age: M = 12.1 years), participated in a range of behavioral memory tasks in which we measured both relational and item-based memory abilities. They also completed a battery of executive function measures. Results: The ASD group showed specific deficits in relational memory, but spared or superior performance in item-based memory, across all tasks. Importantly, for ASD children, executive ability was significantly correlated with relational memory but not with item-based memory. No such relationship was present in the control group. This suggests that children with ASD atypically employed effortful, executive strategies to retrieve relational (but not item-specific) information, whereas TD children appeared to use more automatic processes. Conclusions: The relational memory impairment in ASD may result from a specific impairment in automatic associative retrieval processes with an increased reliance on effortful and strategic retrieval processes. Our findings allow specific neural predictions to be made regarding the interactive functioning of the hippocampus, prefrontal cortex, and posterior parietal cortex in ASD as a neural network supporting relational memory processing. PMID:24245930

Developmental Change in Working Memory Strategies: From Passive Maintenance to Active Refreshing

ERIC Educational Resources Information Center

Camos, Valerie; Barrouillet, Pierre

2011-01-01

Change in strategies is often mentioned as a source of memory development. However, though performance in working memory tasks steadily improves during childhood, theories differ in linking this development to strategy changes. Whereas some theories, such as the time-based resource-sharing model, invoke the age-related increase in use and…

Impaired decision making and delayed memory are related with anxiety and depressive symptoms in acromegaly.

PubMed

Crespo, Iris; Santos, Alicia; Valassi, Elena; Pires, Patricia; Webb, Susan M; Resmini, Eugenia

2015-12-01

Evaluation of cognitive function in acromegaly has revealed contradictory findings; some studies report normal cognition in patients with long-term cured acromegaly, while others show attention and memory deficits. Moreover, the presence of affective disorders in these patients is common. Our aim was to evaluate memory and decision making in acromegalic patients and explore their relationship with affective disorders like anxiety and depressive symptoms. Thirty-one patients with acromegaly (mean age 49.5 ± 8.5 years, 14 females and 17 males) and thirty-one healthy controls participated in this study. The Iowa Gambling Task (IGT), Rey Auditory Verbal Learning Test, State-Trait Anxiety Inventory, and Beck Depression Inventory-II (BDI-II) were used to evaluate decision making, verbal memory, anxiety, and depressive symptoms, respectively. Acromegalic patients showed impairments in delayed verbal memory (p < 0.05) and more anxiety and depressive symptoms (p < 0.05) than controls. In the IGT, acromegalic patients presented an altered decision-making strategy compared to controls, choosing a lower number of the safer cards (p < 0.05) and higher number of the riskier cards (p < 0.05). Moreover, multiple correlations between anxiety and depressive symptoms and performance in memory and decision making were found. Impaired delayed memory and decision making observed in acromegalic patients are related to anxiety and depressive symptoms. Providing emotional support to the patients could improve their cognitive function. A key clinical application of this research is the finding that depressive symptoms and anxiety are essentially modifiable factors.

Impact of metacognition and motivation on the efficacy of strategic memory training in older adults: analysis of specific, transfer and maintenance effects.

PubMed

Carretti, Barbara; Borella, Erika; Zavagnin, Michela; De Beni, Rossana

2011-01-01

The current study examines the contribution of a number of metacognitive and motivational variables in explaining specific, transfer and maintenance effects of a strategic memory training program, based on the use of mental imagery, in older adults. Participants were assessed before and after the training (immediately post-test, and at 3- and 6-month follow-up) on list recall (criterion) and working memory (transfer) tasks. At the pre-test, metacognition (use of strategies, belief about memory, control on memory) and motivational measures (cognitive engagement, self-efficacy) were also collected. The training produced a benefit in both the criterion and transfer tasks, which was maintained at follow-up. Some of the metacognitive and motivational measures, over and above the level of performance obtained at pre-test, predicted the gains in the objective memory measures. The findings confirmed the importance of considering the role of metacognitive attitudes of older adults in memory training activities. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Factors affecting graded and ungraded memory loss following hippocampal lesions.

PubMed

Winocur, Gordon; Moscovitch, Morris; Sekeres, Melanie J

2013-11-01

This review evaluates three current theories--Standard Consolidation (Squire & Wixted, 2011), Overshadowing (Sutherland, Sparks, & Lehmann, 2010), and Multiple Trace-Transformation (Winocur, Moscovitch, & Bontempi, 2010)--in terms of their ability to account for the role of the hippocampus in recent and remote memory in animals. Evidence, based on consistent findings from tests of spatial memory and memory for acquired food preferences, favours the transformation account, but this conclusion is undermined by inconsistent results from studies that measured contextual fear memory, probably the most commonly used test of hippocampal involvement in anterograde and retrograde memory. Resolution of this issue may depend on exercising greater control over critical factors (e.g., contextual environment, amount of pre-exposure to the conditioning chamber, the number and distribution of foot-shocks) that can affect the representation of the memory shortly after learning and over the long-term. Research strategies aimed at characterizing the neural basis of long-term consolidation/transformation, as well as other outstanding issues are discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

Question structure impacts efficiency and performance in an interactive guessing game: implications for strategy engagement and executive functioning.

PubMed

Longenecker, Julia; Liu, Kristy; Chen, Eric Y H

2012-12-30

In an interactive guessing game, controls had higher performance and efficiency than patients with schizophrenia in correct trials. Patients' difficulties generating efficient questions suggest an increased taxation of working memory and an inability to engage an appropriate strategy, leading to impulsive behavior and reduced success. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Memory Self-Efficacy and Strategy Use in Successful Elders.

ERIC Educational Resources Information Center

McDougall, Graham J.

1995-01-01

The Metamemory in Adulthood Questionnaire, Memory Self-Efficacy Questionnaire, and measures of depression and health status were completed by 169 adults over 55 in Texas and Louisiana. External memory strategies (lists, notes) were used more often than internal (elaboration, rehearsal). Memory efficacy decreased significantly with age, and anxiety…

Stress Modulates the Use of Spatial versus Stimulus-Response Learning Strategies in Humans

ERIC Educational Resources Information Center

Philippsen, Christine; Richter, Steffen; Bohringer, Andreas; Wippich, Werner; Schachinger, Hartmut; Schwabe, Lars; Oitzl, Melly S.

2007-01-01

Animal studies provided evidence that stress modulates multiple memory systems, favoring caudate nucleus-based "habit" memory over hippocampus-based "cognitive" memory. However, effects of stress on learning strategy and memory consolidation were not differentiated. We specifically address the effects of psychosocial stress on the applied learning…

Memory and Study Strategies for Optimal Learning.

ERIC Educational Resources Information Center

Hamachek, Alice L.

Study strategies are those specific reading skills that increase understanding, memory storage, and retrieval. Memory techniques are crucial to effective studying, and to subsequent performance in class and on written examinations. A major function of memory is to process information. Stimuli are picked up by sensory receptors and transferred to…

Adaptive online inverse control of a shape memory alloy wire actuator using a dynamic neural network

NASA Astrophysics Data System (ADS)

Mai, Huanhuan; Song, Gangbing; Liao, Xiaofeng

2013-01-01

Shape memory alloy (SMA) actuators exhibit severe hysteresis, a nonlinear behavior, which complicates control strategies and limits their applications. This paper presents a new approach to controlling an SMA actuator through an adaptive inverse model based controller that consists of a dynamic neural network (DNN) identifier, a copy dynamic neural network (CDNN) feedforward term and a proportional (P) feedback action. Unlike fixed hysteresis models used in most inverse controllers, the proposed one uses a DNN to identify online the relationship between the applied voltage to the actuator and the displacement (the inverse model). Even without a priori knowledge of the SMA hysteresis and without pre-training, the proposed controller can precisely control the SMA wire actuator in various tracking tasks by identifying online the inverse model of the SMA actuator. Experiments were conducted, and experimental results demonstrated real-time modeling capabilities of DNN and the performance of the adaptive inverse controller.

Memory-based decision-making with heuristics: evidence for a controlled activation of memory representations.

PubMed

Khader, Patrick H; Pachur, Thorsten; Meier, Stefanie; Bien, Siegfried; Jost, Kerstin; Rösler, Frank

2011-11-01

Many of our daily decisions are memory based, that is, the attribute information about the decision alternatives has to be recalled. Behavioral studies suggest that for such decisions we often use simple strategies (heuristics) that rely on controlled and limited information search. It is assumed that these heuristics simplify decision-making by activating long-term memory representations of only those attributes that are necessary for the decision. However, from behavioral studies alone, it is unclear whether using heuristics is indeed associated with limited memory search. The present study tested this assumption by monitoring the activation of specific long-term-memory representations with fMRI while participants made memory-based decisions using the "take-the-best" heuristic. For different decision trials, different numbers and types of information had to be retrieved and processed. The attributes consisted of visual information known to be represented in different parts of the posterior cortex. We found that the amount of information required for a decision was mirrored by a parametric activation of the dorsolateral PFC. Such a parametric pattern was also observed in all posterior areas, suggesting that activation was not limited to those attributes required for a decision. However, the posterior increases were systematically modulated by the relative importance of the information for making a decision. These findings suggest that memory-based decision-making is mediated by the dorsolateral PFC, which selectively controls posterior storage areas. In addition, the systematic modulations of the posterior activations indicate a selective boosting of activation of decision-relevant attributes.

Self-regulation and the specificity of autobiographical memory in offenders.

PubMed

Neves, Daniela; Pinho, Maria S

Certain clinical populations exhibit an Overgeneral Autobiographical Memory (OAM), characterized by difficulty remembering specific events. One study has observed OAM for positive events in a group of offenders. This study analyzed the stability of the valence effect in the OAM of offenders, the executive control impairments facilitating OAM in offenders, and the relationship of self-esteem and social desirability with AM specificity. The specificity (Autobiographical Memory Test) and emotional properties of the AMs of 59 prisoners (30 men, 29 women) and a control group (29 men, 30 women) were compared. Social desirability, depression symptoms, self-esteem and executive functions (Mazes, Stroop, Verbal Fluency) were assessed. The offenders recalled fewer specific positive AMs than controls, and did not perceive the emotional intensity of their negative AMs to decrease over time, unlike the controls. The offenders' recall of specific negative AMs seemed to influence negatively their performance in the subsequent executive control tasks. Dysfunctional coping strategies in offenders were related to OAM, but not social desirability or self-esteem. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of gender and executive function on visuospatial working memory in adult obsessive-compulsive disorder.

PubMed

Martoni, Riccardo Maria; Salgari, Giulia; Galimberti, Elisa; Cavallini, Maria Cristina; O'Neill, Joseph

2015-12-01

Visuospatial working memory (VSWM) is the ability of the brain to transiently store and manipulate visual information. VSWM deficiencies have been reported in obsessive-compulsive disorder (OCD), but not consistently, perhaps due to variability in task design and clinical patient factors. To explore this variability, this study assessed effects of the design factors task difficulty and executive organizational strategy and of the clinical factors gender, OCD symptom dimension, and duration of illness on VSWM in OCD. The CANTAB spatial working memory, spatial recognition memory, delayed matching to sample, and stop signal tasks were administered to 42 adult OCD patients and 42 age- and sex-matched healthy controls. Aims were to detect a possible VSWM deficit in the OCD sample, to evaluate influences of the above task and patient factors, to determine the specificity of the deficit to the visuospatial subdomain, and to examine effects of sustained attention as potential neurocognitive confound. We confirmed previous findings of a VSWM deficit in OCD that was more severe for greater memory load (task difficulty) and that was affected by task strategy (executive function). We failed to demonstrate significant deficits in neighboring or confounding neurocognitive subdomains (visual object recognition or visual object short-term memory, sustained attention). Notably, the VSWM deficit was only significant for female patients, adding to evidence for sexual dimorphism in OCD. Again as in prior work, more severe OCD symptoms in the symmetry dimension (but no other dimension) significantly negatively impacted VSWM. Duration of illness had no significant effect on VSWM. VSWM deficits in OCD appear more severe with higher task load and may be mediated through poor task strategy. Such deficits may present mainly in female patients and in (male and female) patients with symmetry symptoms.

Chemoprophylaxis with sporozoite immunization in P. knowlesi rhesus monkeys confers protection and elicits sporozoite-specific memory T cells in the liver

PubMed Central

Spring, Michele D.; Yongvanitchit, Kosol; Kum-Arb, Utaiwan; Limsalakpetch, Amporn; Im-Erbsin, Rawiwan; Ubalee, Ratawan; Vanachayangkul, Pattaraporn; Remarque, Edmond J.; Angov, Evelina; Smith, Philip L.; Saunders, David L.

2017-01-01

Whole malaria sporozoite vaccine regimens are promising new strategies, and some candidates have demonstrated high rates of durable clinical protection associated with memory T cell responses. Little is known about the anatomical distribution of memory T cells following whole sporozoite vaccines, and immunization of nonhuman primates can be used as a relevant model for humans. We conducted a chemoprophylaxis with sporozoite (CPS) immunization in P. knowlesi rhesus monkeys and challenged via mosquito bites. Half of CPS immunized animals developed complete protection, with a marked delay in parasitemia demonstrated in the other half. Antibody responses to whole sporozoites, CSP, and AMA1, but not CelTOS were detected. Peripheral blood T cell responses to whole sporozoites, but not CSP and AMA1 peptides were observed. Unlike peripheral blood, there was a high frequency of sporozoite-specific memory T cells observed in the liver and bone marrow. Interestingly, sporozoite-specific CD4+ and CD8+ memory T cells in the liver highly expressed chemokine receptors CCR5 and CXCR6, both of which are known for liver sinusoid homing. The majority of liver sporozoite-specific memory T cells expressed CD69, a phenotypic marker of tissue-resident memory (TRM) cells, which are well positioned to rapidly control liver-stage infection. Vaccine strategies that aim to elicit large number of liver TRM cells may efficiently increase the efficacy and durability of response against pre-erythrocytic parasites. PMID:28182750

Compiler-directed cache management in multiprocessors

NASA Technical Reports Server (NTRS)

Cheong, Hoichi; Veidenbaum, Alexander V.

1990-01-01

The necessity of finding alternatives to hardware-based cache coherence strategies for large-scale multiprocessor systems is discussed. Three different software-based strategies sharing the same goals and general approach are presented. They consist of a simple invalidation approach, a fast selective invalidation scheme, and a version control scheme. The strategies are suitable for shared-memory multiprocessor systems with interconnection networks and a large number of processors. Results of trace-driven simulations conducted on numerical benchmark routines to compare the performance of the three schemes are presented.

Prospective memory rehabilitation using smartphones in patients with TBI: What do participants report?

PubMed

Evald, Lars

2015-01-01

Use of assistive devices has been shown to be beneficial as a compensatory memory strategy among brain injury survivors, but little is known about possible advantages and disadvantages of the technology. As part of an intervention study participants were interviewed about their experiences with the use of low-cost, off-the-shelf, unmodified smartphones combined with Internet calendars as a compensatory memory strategy. Thirteen community-dwelling patients with traumatic brain injury (TBI) received a 6-week group-based instruction in the systematic use of a smartphone as a memory compensatory aid followed by a brief structured open-ended interview regarding satisfaction with and advantages and disadvantages of the compensatory strategy. Ten of 13 participants continued to use a smartphone as their primary compensatory strategy. Audible and visual reminders were the most frequently mentioned advantages of the smartphone, and, second, the capability as an all-in-one memory device. In contrast, battery life was the most often mentioned disadvantage, followed by concerns about loss or failure of the device. Use of a smartphone seems to be a satisfactory compensatory memory strategy to many patients with TBI and smartphones come with features that are advantageous to other compensatory strategies. However, some benefits come hand-in-hand with drawbacks, such as the feeling of dependency. These aspects should be taken into account when choosing assistive technology as a memory compensatory strategy.

A finite-state, finite-memory minimum principle, part 2

NASA Technical Reports Server (NTRS)

Sandell, N. R., Jr.; Athans, M.

1975-01-01

In part 1 of this paper, a minimum principle was found for the finite-state, finite-memory (FSFM) stochastic control problem. In part 2, conditions for the sufficiency of the minimum principle are stated in terms of the informational properties of the problem. This is accomplished by introducing the notion of a signaling strategy. Then a min-H algorithm based on the FSFM minimum principle is presented. This algorithm converges, after a finite number of steps, to a person - by - person extremal solution.

Strategies for concurrent processing of complex algorithms in data driven architectures

NASA Technical Reports Server (NTRS)

Stoughton, John W.; Mielke, Roland R.

1988-01-01

The purpose is to document research to develop strategies for concurrent processing of complex algorithms in data driven architectures. The problem domain consists of decision-free algorithms having large-grained, computationally complex primitive operations. Such are often found in signal processing and control applications. The anticipated multiprocessor environment is a data flow architecture containing between two and twenty computing elements. Each computing element is a processor having local program memory, and which communicates with a common global data memory. A new graph theoretic model called ATAMM which establishes rules for relating a decomposed algorithm to its execution in a data flow architecture is presented. The ATAMM model is used to determine strategies to achieve optimum time performance and to develop a system diagnostic software tool. In addition, preliminary work on a new multiprocessor operating system based on the ATAMM specifications is described.

Central Executive Dysfunction and Deferred Prefrontal Processing in Veterans with Gulf War Illness.

PubMed

Hubbard, Nicholas A; Hutchison, Joanna L; Motes, Michael A; Shokri-Kojori, Ehsan; Bennett, Ilana J; Brigante, Ryan M; Haley, Robert W; Rypma, Bart

2014-05-01

Gulf War Illness is associated with toxic exposure to cholinergic disruptive chemicals. The cholinergic system has been shown to mediate the central executive of working memory (WM). The current work proposes that impairment of the cholinergic system in Gulf War Illness patients (GWIPs) leads to behavioral and neural deficits of the central executive of WM. A large sample of GWIPs and matched controls (MCs) underwent functional magnetic resonance imaging during a varied-load working memory task. Compared to MCs, GWIPs showed a greater decline in performance as WM-demand increased. Functional imaging suggested that GWIPs evinced separate processing strategies, deferring prefrontal cortex activity from encoding to retrieval for high demand conditions. Greater activity during high-demand encoding predicted greater WM performance. Behavioral data suggest that WM executive strategies are impaired in GWIPs. Functional data further support this hypothesis and suggest that GWIPs utilize less effective strategies during high-demand WM.

Central Executive Dysfunction and Deferred Prefrontal Processing in Veterans with Gulf War Illness

PubMed Central

Hubbard, Nicholas A.; Hutchison, Joanna L.; Motes, Michael A.; Shokri-Kojori, Ehsan; Bennett, Ilana J.; Brigante, Ryan M.; Haley, Robert W.; Rypma, Bart

2015-01-01

Gulf War Illness is associated with toxic exposure to cholinergic disruptive chemicals. The cholinergic system has been shown to mediate the central executive of working memory (WM). The current work proposes that impairment of the cholinergic system in Gulf War Illness patients (GWIPs) leads to behavioral and neural deficits of the central executive of WM. A large sample of GWIPs and matched controls (MCs) underwent functional magnetic resonance imaging during a varied-load working memory task. Compared to MCs, GWIPs showed a greater decline in performance as WM-demand increased. Functional imaging suggested that GWIPs evinced separate processing strategies, deferring prefrontal cortex activity from encoding to retrieval for high demand conditions. Greater activity during high-demand encoding predicted greater WM performance. Behavioral data suggest that WM executive strategies are impaired in GWIPs. Functional data further support this hypothesis and suggest that GWIPs utilize less effective strategies during high-demand WM. PMID:25767746

The Development of Strategy Use in Elementary School Children: Working Memory and Individual Differences

ERIC Educational Resources Information Center

Imbo, Ineke; Vandierendonck, Andre

2007-01-01

The current study tested the development of working memory involvement in children's arithmetic strategy selection and strategy efficiency. To this end, an experiment in which the dual-task method and the choice/no-choice method were combined was administered to 10- to 12-year-olds. Working memory was needed in retrieval, transformation, and…

Comparative Effect of Memory and Cognitive Strategies Training on EFL Intermediate Learners' Vocabulary Learning

ERIC Educational Resources Information Center

Banisaeid, Maryam

2013-01-01

The present study was conducted to compare the effect of memory and cognitive strategies training on vocabulary learning of intermediate proficiency group of Iranian learners of English as a foreign language. It is to check how memory and cognitive strategies training affect word learning of EFL intermediate learners (N = 60) who were homogenized…

Increasing relational memory in childhood with unitization strategies.

PubMed

Robey, Alison; Riggins, Tracy

2018-01-01

Young children often experience relational memory failures, which are thought to result from immaturity of the recollection processes presumed to be required for these tasks. However, research in adults has suggested that relational memory tasks can be accomplished using familiarity, a process thought to be mature by the end of early childhood. The goal of the present study was to determine whether relational memory performance could be improved in childhood by teaching young children memory strategies that have been shown to increase the contribution of familiarity in adults (i.e., unitization). Groups of 6- and 8-year-old children were taught to use visualization strategies that either unitized or did not unitize pictures and colored borders. Estimates of familiarity and recollection were extracted by fitting receiver operator characteristic curves (Yonelinas, Journal of Experimental Psychology: Learning, Memory, and Cognition 20, 1341-1354, 1994, Yonelinas, Memory & Cognition 25, 747-763, 1997) based on dual-process models of recognition. Bayesian analysis revealed that strategies involving unitization improved memory performance and increased the contribution of familiarity in both age groups.

Local digital control of power electronic converters in a dc microgrid based on a-priori derivation of switching surfaces

NASA Astrophysics Data System (ADS)

Banerjee, Bibaswan

In power electronic basedmicrogrids, the computational requirements needed to implement an optimized online control strategy can be prohibitive. The work presented in this dissertation proposes a generalized method of derivation of geometric manifolds in a dc microgrid that is based on the a-priori computation of the optimal reactions and trajectories for classes of events in a dc microgrid. The proposed states are the stored energies in all the energy storage elements of the dc microgrid and power flowing into them. It is anticipated that calculating a large enough set of dissimilar transient scenarios will also span many scenarios not specifically used to develop the surface. These geometric manifolds will then be used as reference surfaces in any type of controller, such as a sliding mode hysteretic controller. The presence of switched power converters in microgrids involve different control actions for different system events. The control of the switch states of the converters is essential for steady state and transient operations. A digital memory look-up based controller that uses a hysteretic sliding mode control strategy is an effective technique to generate the proper switch states for the converters. An example dcmicrogrid with three dc-dc boost converters and resistive loads is considered for this work. The geometric manifolds are successfully generated for transient events, such as step changes in the loads and the sources. The surfaces corresponding to a specific case of step change in the loads are then used as reference surfaces in an EEPROM for experimentally validating the control strategy. The required switch states corresponding to this specific transient scenario are programmed in the EEPROM as a memory table. This controls the switching of the dc-dc boost converters and drives the system states to the reference manifold. In this work, it is shown that this strategy effectively controls the system for a transient condition such as step changes in the loads for the example case.

Memory-Scalable GPU Spatial Hierarchy Construction.

PubMed

Qiming Hou; Xin Sun; Kun Zhou; Lauterbach, C; Manocha, D

2011-04-01

Recent GPU algorithms for constructing spatial hierarchies have achieved promising performance for moderately complex models by using the breadth-first search (BFS) construction order. While being able to exploit the massive parallelism on the GPU, the BFS order also consumes excessive GPU memory, which becomes a serious issue for interactive applications involving very complex models with more than a few million triangles. In this paper, we propose to use the partial breadth-first search (PBFS) construction order to control memory consumption while maximizing performance. We apply the PBFS order to two hierarchy construction algorithms. The first algorithm is for kd-trees that automatically balances between the level of parallelism and intermediate memory usage. With PBFS, peak memory consumption during construction can be efficiently controlled without costly CPU-GPU data transfer. We also develop memory allocation strategies to effectively limit memory fragmentation. The resulting algorithm scales well with GPU memory and constructs kd-trees of models with millions of triangles at interactive rates on GPUs with 1 GB memory. Compared with existing algorithms, our algorithm is an order of magnitude more scalable for a given GPU memory bound. The second algorithm is for out-of-core bounding volume hierarchy (BVH) construction for very large scenes based on the PBFS construction order. At each iteration, all constructed nodes are dumped to the CPU memory, and the GPU memory is freed for the next iteration's use. In this way, the algorithm is able to build trees that are too large to be stored in the GPU memory. Experiments show that our algorithm can construct BVHs for scenes with up to 20 M triangles, several times larger than previous GPU algorithms.

Cholinergic blockade under working memory demands encountered by increased rehearsal strategies: evidence from fMRI in healthy subjects.

PubMed

Voss, Bianca; Thienel, Renate; Reske, Martina; Kellermann, Thilo; Sheldrick, Abigail J; Halfter, Sarah; Radenbach, Katrin; Shah, Nadim J; Habel, Ute; Kircher, Tilo T J

2012-06-01

The connection between cholinergic transmission and cognitive performance has been established in behavioural studies. The specific contribution of the muscarinic receptor system on cognitive performance and brain activation, however, has not been evaluated satisfyingly. To investigate the specific contribution of the muscarinic transmission on neural correlates of working memory, we examined the effects of scopolamine, an antagonist of the muscarinic receptors, using functional magnetic resonance imaging (fMRI). Fifteen healthy male, non-smoking subjects performed a fMRI scanning session following the application of scopolamine (0.4 mg, i.v.) or saline in a placebo-controlled, repeated measure, pseudo-randomized, single-blind design. Working memory was probed using an n-back task. Compared to placebo, challenging the cholinergic transmission with scopolamine resulted in hypoactivations in parietal, occipital and cerebellar areas and hyperactivations in frontal and prefrontal areas. These alterations are interpreted as compensatory strategies used to account for downregulation due to muscarinic acetylcholine blockade in parietal and cerebral storage systems by increased activation in frontal and prefrontal areas related to working memory rehearsal. Our results further underline the importance of cholinergic transmission to working memory performance and determine the specific contribution of muscarinic transmission on cerebral activation associated with executive functioning.

Intrinsic spontaneous brain activity predicts individual variability in associative memory in older adults.

PubMed

Zheng, Zhiwei; Li, Rui; Xiao, Fengqiu; He, Rongqiao; Zhang, Shouzi; Li, Juan

2018-06-01

Older adults demonstrate notable individual differences in associative memory. Here, resting-state functional magnetic resonance imaging (rsfMRI) was used to investigate whether intrinsic brain activity at rest could predict individual differences in associative memory among cognitively healthy older adults. Regional amplitude of low-frequency fluctuations (ALFF) analysis and a correlation-based resting-state functional connectivity (RSFC) approach were used to analyze data acquired from 102 cognitively normal elderly who completed the paired-associative learning test (PALT) and underwent fMRI scans. Participants were divided into two groups based on the retrospective self-reports on whether or not they utilized encoding strategies during the PALT. The behavioral results revealed better associative memory performance in the participants who reported utilizing memory strategies compared with participants who reported not doing so. The fMRI results showed that higher associative memory performance was associated with greater functional connectivity between the right superior frontal gyrus and the right posterior cerebellum lobe in the strategy group. The regional ALFF values in the right superior frontal gyrus were linked to associative memory performance in the no-strategy group. These findings suggest that the regional spontaneous fluctuations and functional connectivity during rest may subserve the individual differences in the associative memory in older adults, and that this is modulated by self-initiated memory strategy use. © 2018 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Working-memory capacity protects model-based learning from stress.

PubMed

Otto, A Ross; Raio, Candace M; Chiang, Alice; Phelps, Elizabeth A; Daw, Nathaniel D

2013-12-24

Accounts of decision-making have long posited the operation of separate, competing valuation systems in the control of choice behavior. Recent theoretical and experimental advances suggest that this classic distinction between habitual and goal-directed (or more generally, automatic and controlled) choice may arise from two computational strategies for reinforcement learning, called model-free and model-based learning. Popular neurocomputational accounts of reward processing emphasize the involvement of the dopaminergic system in model-free learning and prefrontal, central executive-dependent control systems in model-based choice. Here we hypothesized that the hypothalamic-pituitary-adrenal (HPA) axis stress response--believed to have detrimental effects on prefrontal cortex function--should selectively attenuate model-based contributions to behavior. To test this, we paired an acute stressor with a sequential decision-making task that affords distinguishing the relative contributions of the two learning strategies. We assessed baseline working-memory (WM) capacity and used salivary cortisol levels to measure HPA axis stress response. We found that stress response attenuates the contribution of model-based, but not model-free, contributions to behavior. Moreover, stress-induced behavioral changes were modulated by individual WM capacity, such that low-WM-capacity individuals were more susceptible to detrimental stress effects than high-WM-capacity individuals. These results enrich existing accounts of the interplay between acute stress, working memory, and prefrontal function and suggest that executive function may be protective against the deleterious effects of acute stress.

Working-memory capacity protects model-based learning from stress

PubMed Central

Otto, A. Ross; Raio, Candace M.; Chiang, Alice; Phelps, Elizabeth A.; Daw, Nathaniel D.

2013-01-01

Accounts of decision-making have long posited the operation of separate, competing valuation systems in the control of choice behavior. Recent theoretical and experimental advances suggest that this classic distinction between habitual and goal-directed (or more generally, automatic and controlled) choice may arise from two computational strategies for reinforcement learning, called model-free and model-based learning. Popular neurocomputational accounts of reward processing emphasize the involvement of the dopaminergic system in model-free learning and prefrontal, central executive–dependent control systems in model-based choice. Here we hypothesized that the hypothalamic-pituitary-adrenal (HPA) axis stress response—believed to have detrimental effects on prefrontal cortex function—should selectively attenuate model-based contributions to behavior. To test this, we paired an acute stressor with a sequential decision-making task that affords distinguishing the relative contributions of the two learning strategies. We assessed baseline working-memory (WM) capacity and used salivary cortisol levels to measure HPA axis stress response. We found that stress response attenuates the contribution of model-based, but not model-free, contributions to behavior. Moreover, stress-induced behavioral changes were modulated by individual WM capacity, such that low-WM-capacity individuals were more susceptible to detrimental stress effects than high-WM-capacity individuals. These results enrich existing accounts of the interplay between acute stress, working memory, and prefrontal function and suggest that executive function may be protective against the deleterious effects of acute stress. PMID:24324166

Working Memory, Strategy Knowledge, and Strategy Instruction in Children with Reading Disabilities

ERIC Educational Resources Information Center

Swanson, H. Lee; Kehler, Pam; Jerman, Olga

2010-01-01

Two experiments investigated the effects of strategy knowledge and strategy training on the working memory (WM) performance in children (ages 10-11) with and without reading disabilities (RD). Experiment 1 examined the relationship between strategy knowledge (stability of strategy choices) and WM performance as a function of initial, gain (cued),…

Efficacy of memory rehabilitation therapy: a meta-analysis of TBI and stroke cognitive rehabilitation literature.

PubMed

Elliott, Madison; Parente, Frederick

2014-01-01

To examine the efficacy of cognitive rehabilitation strategies specifically designed to improve memory after traumatic brain injury (TBI) and stroke vs. memory improvement with the passage of time. A meta-analysis was performed on 26 studies of memory retraining and recovery that were published between the years of 1985 and 2013. Effect sizes (ESs) from each study were calculated and converted to Pearson's r and then analysed to assess the overall effect size and the relationship among the ESs, patient demographics and treatment interventions. RESULTS indicated a significant average ES (r = 0.51) in the treatment intervention conditions, as well as a significant average ES (r = 0.31) in the control conditions, in which participants did not receive any treatment. The largest ESs occurred in studies of stroke patients and studies concerning working memory rehabilitation. RESULTS showed that memory rehabilitation was an effective therapeutic intervention, especially for stroke patients and for working memory as a treatment domain. However, the results also indicated that significant memory improvement occurred spontaneously over time.

Enhancing memory self-efficacy during menopause through a group memory strategies program.

PubMed

Unkenstein, Anne E; Bei, Bei; Bryant, Christina A

2017-05-01

Anxiety about memory during menopause can affect quality of life. We aimed to improve memory self-efficacy during menopause using a group memory strategies program. The program was run five times for a total of 32 peri- and postmenopausal women, age between 47 and 60 years, recruited from hospital menopause and gynecology clinics. The 4-week intervention consisted of weekly 2-hour sessions, and covered how memory works, memory changes related to ageing, health and lifestyle factors, and specific memory strategies. Memory contentment (CT), reported frequency of forgetting (FF), use of memory strategies, psychological distress, and attitude toward menopause were measured. A double-baseline design was applied, with outcomes measured on two baseline occasions (1-month prior [T1] and in the first session [T2]), immediately postintervention (T3), and 3-month postintervention (T4). To describe changes in each variable between time points paired sample t tests were conducted. Mixed-effects models comparing the means of random slopes from T2 to T3 with those from T1 to T2 were conducted for each variable to test for treatment effects. Examination of the naturalistic changes in outcome measures from T1 to T2 revealed no significant changes (all Ps > 0.05). CT, reported FF, and use of memory strategies improved significantly more from T2 to T3, than from T1 to T2 (all Ps < 0.05). Neither attitude toward menopause nor psychological distress improved significantly more postintervention than during the double-baseline (all Ps > 0.05). Improvements in reported CT and FF were maintained after 3 months. The use of group interventions to improve memory self-efficacy during menopause warrants continued evaluation.

Strategic search from long-term memory: an examination of semantic and autobiographical recall.

PubMed

Unsworth, Nash; Brewer, Gene A; Spillers, Gregory J

2014-01-01

Searching long-term memory is theoretically driven by both directed (search strategies) and random components. In the current study we conducted four experiments evaluating strategic search in semantic and autobiographical memory. Participants were required to generate either exemplars from the category of animals or the names of their friends for several minutes. Self-reported strategies suggested that participants typically relied on visualization strategies for both tasks and were less likely to rely on ordered strategies (e.g., alphabetic search). When participants were instructed to use particular strategies, the visualization strategy resulted in the highest levels of performance and the most efficient search, whereas ordered strategies resulted in the lowest levels of performance and fairly inefficient search. These results are consistent with the notion that retrieval from long-term memory is driven, in part, by search strategies employed by the individual, and that one particularly efficient strategy is to visualize various situational contexts that one has experienced in the past in order to constrain the search and generate the desired information.

Do Improved Patient Recall and the Provision of Memory Support Enhance Treatment Adherence?

PubMed Central

Dong, Lu; Lee, Jason Y.; Harvey, Allison G.

2017-01-01

Background and Objectives Patient adherence to psychosocial treatment is an important but understudied topic. The aim of this study was to examine whether better patient recall of treatment contents and therapist use of memory support (MS) were associated with better treatment adherence. Methods Data were drawn from a pilot randomized controlled trial. Participants were 48 individuals (mean age = 44.27 years, 29 females) with Major Depressive Disorder randomized to receive either Cognitive Therapy (CT) with an adjunctive Memory Support Intervention (CT+Memory Support) or CT-as-usual. Therapist and patient ratings of treatment adherence were collected during each treatment session. Patient recall was assessed at mid-treatment. Therapist use of MS was manually coded for a random selection of sessions. Results Patient recall was significantly associated with better therapist and patient ratings of adherence. Therapist use of Application, a specific MS strategy, predicted higher therapist ratings of adherence. Attention Recruitment, another specific MS strategy, appeared to attenuate the positive impact of session number on patient ratings of adherence. Treatment groups, MS summary scores and other specific MS strategies were not significantly associated with adherence. Limitations The measure for treatment adherence is in the process of being formally validated. Results were based on small sample. Conclusions These results support the importance of patient recall in treatment adherence. Although collectively the effects of MS on treatment adherence were not significant, the results support the use of certain specific MS strategy (i.e., application) as a potential pathway to improve treatment adherence. Larger-scale studies are needed to further examine these constructs. PMID:27614662

Do improved patient recall and the provision of memory support enhance treatment adherence?

PubMed

Dong, Lu; Lee, Jason Y; Harvey, Allison G

2017-03-01

Patient adherence to psychosocial treatment is an important but understudied topic. The aim of this study was to examine whether better patient recall of treatment contents and therapist use of memory support (MS) were associated with better treatment adherence. Data were drawn from a pilot randomized controlled trial. Participants were 48 individuals (mean age = 44.27 years, 29 females) with Major Depressive Disorder randomized to receive either Cognitive Therapy (CT) with an adjunctive Memory Support Intervention (CT + Memory Support) or CT-as-usual. Therapist and patient ratings of treatment adherence were collected during each treatment session. Patient recall was assessed at mid-treatment. Therapist use of MS was manually coded for a random selection of sessions. Patient recall was significantly associated with better therapist and patient ratings of adherence. Therapist use of Application, a specific MS strategy, predicted higher therapist ratings of adherence. Attention Recruitment, another specific MS strategy, appeared to attenuate the positive impact of session number on patient ratings of adherence. Treatment groups, MS summary scores and other specific MS strategies were not significantly associated with adherence. The measure for treatment adherence is in the process of being formally validated. Results were based on small sample. These results support the importance of patient recall in treatment adherence. Although collectively the effects of MS on treatment adherence were not significant, the results support the use of certain specific MS strategy (i.e., application) as a potential pathway to improve treatment adherence. Larger-scale studies are needed to further examine these constructs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Developmental and Individual Differences in Young Children's Use and Maintenance of a Selective Memory Strategy

ERIC Educational Resources Information Center

Schwenck, Christina; Bjorklund, David F.; Schneider, Wolfgang

2009-01-01

Children who were 4 to 8 years of age were asked to perform a sort-recall task where only half of the items had to be studied and remembered. Following a baseline trial, children were assigned to 1 of 3 groups and were prompted to use either a sorting or a clustering strategy (experimental groups) or were not prompted at all (control group).…

Dorsolateral prefrontal lesions do not impair tests of scene learning and decision-making that require frontal–temporal interaction

PubMed Central

Baxter, Mark G; Gaffan, David; Kyriazis, Diana A; Mitchell, Anna S

2008-01-01

Theories of dorsolateral prefrontal cortex (DLPFC) involvement in cognitive function variously emphasize its involvement in rule implementation, cognitive control, or working and/or spatial memory. These theories predict broad effects of DLPFC lesions on tests of visual learning and memory. We evaluated the effects of DLPFC lesions (including both banks of the principal sulcus) in rhesus monkeys on tests of scene learning and strategy implementation that are severely impaired following crossed unilateral lesions of frontal cortex and inferotemporal cortex. Dorsolateral lesions had no effect on learning of new scene problems postoperatively, or on the implementation of preoperatively acquired strategies. They were also without effect on the ability to adjust choice behaviour in response to a change in reinforcer value, a capacity that requires interaction between the amygdala and frontal lobe. These intact abilities following DLPFC damage support specialization of function within the prefrontal cortex, and suggest that many aspects of memory and strategic and goal-directed behaviour can survive ablation of this structure. PMID:18702721

Design and feasibility of a memory intervention with focus on self-management for cognitive impairment in epilepsy.

PubMed

Caller, Tracie A; Secore, Karen L; Ferguson, Robert J; Roth, Robert M; Alexandre, Faith P; Henegan, Patricia L; Harrington, Jessica J; Jobst, Barbara C

2015-03-01

The aim of this study was to assess the feasibility of a self-management intervention targeting cognitive dysfunction to improve quality of life and reduce memory-related disability in adults with epilepsy. The intervention incorporates (1) education on cognitive function in epilepsy, (2) self-awareness training, (3) compensatory strategies, and (4) application of these strategies in day-to-day life using problem-solving therapy. In addition to the behavioral modification, formal working memory training was conducted by utilizing a commercially available program in a subgroup of patients. Our findings suggest that a self-management intervention targeting cognitive dysfunction was feasible for delivery to a rural population with epilepsy, with 13 of 16 enrolled participants completing the 8-session program. Qualitative data indicate high satisfaction and subjective improvement in cognitive functioning in day-to-day life. These findings provide support for further evaluation of the efficacy of this intervention through a randomized controlled trial. Copyright © 2015 Elsevier Inc. All rights reserved.

A Preliminary Investigation of Temperature Dependency of a Shape Memory Actuator with Time-Based Control in Aircraft Interiors

NASA Astrophysics Data System (ADS)

Otibar, Dennis; Weirich, Antonia; Kortenjann, Marcus; Kuhlenkötter, Bernd

2017-06-01

Shape memory alloys (SMA) possess an array of unique functional properties which are influenced by a complex interaction of different factors. Due to thermal sensitivity, slight changes in the environmental temperature may cause the properties to change significantly. This poses a huge challenge especially for the use of SMAs as actuators. The most common and elementary activation strategy of SMA actuators is based on the duration of activation and cooling with constant activation parameters. However, changing environmental influences cause the necessity to modify these parameters. This circumstance needs to be especially considered in the design process of actuator controls. This paper focuses on investigating the influence of environmental temperature changes on time-based activated SMA actuators. The results of the described experiments form the base for designing reactive control strategies for SMA actuators used in alternating environments. An example for application fields with changing environments and particularly changing temperatures are aircraft related implementations. This area also stands to benefit from the actuators’ advantages in ecological efficiency.

Working Memory and Strategy Use Contribute to Gender Differences in Spatial Ability

ERIC Educational Resources Information Center

Wang, Lu; Carr, Martha

2014-01-01

In this review, a new model that is grounded in information-processing theory is proposed to account for gender differences in spatial ability. The proposed model assumes that the relative strength of working memory, as expressed by the ratio of visuospatial working memory to verbal working memory, influences the type of strategies used on spatial…

Search and the Aging Mind: The Promise and Limits of the Cognitive Control Hypothesis of Age Differences in Search.

PubMed

Mata, Rui; von Helversen, Bettina

2015-07-01

Search is a prerequisite for successful performance in a broad range of tasks ranging from making decisions between consumer goods to memory retrieval. How does aging impact search processes in such disparate situations? Aging is associated with structural and neuromodulatory brain changes that underlie cognitive control processes, which in turn have been proposed as a domain-general mechanism controlling search in external environments as well as memory. We review the aging literature to evaluate the cognitive control hypothesis that suggests that age-related change in cognitive control underlies age differences in both external and internal search. We also consider the limits of the cognitive control hypothesis and propose additional mechanisms such as changes in strategy use and affect that may be necessary to understand how aging affects search. Copyright © 2015 Cognitive Science Society, Inc.

Ameliorative effect of rosmarinic acid on scopolamine-induced memory impairment in rats.

PubMed

Hasanein, Parisa; Mahtaj, Azam Kazemian

2015-01-12

Rosmarinic acid (RA) is a natural phenol that exerts different biological activities, such as antioxidant activity and neuroprotective effects. In this study, we hypothesized that administration of RA (8, 16, and 32 mg/kg, p.o.) for 7 days would effect on scopolamine-induced cognitive dysfunction as an extensively used model of cognitive impairment. The rats were divided into 10 groups. The acquisition trial was done 1h after the last administration of RA. Animals were divided into control, RA (8, 16, and 32 mg/kg) and donepezil (2 mg/kg) treated controls, scopolamine, RA (8, 16, and 32 mg/kg), and donepezil (2 mg/kg) treated scopolamine groups. Memory impairment was induced by scopolamine treatment (1 mg/kg, i.p.) 30 min after the administration of RA, donepezil, or saline. Scopolamine administration caused cognition deficits in the PAL and memory paradigm. While orally RA administration (16 and 32 mg/kg) improved learning and memory in control rats, it reversed learning and memory deficits of scopolamine received groups. Administration of RA at the dose of 8 mg/kg did not alter cognitive function in control and scopolamine treated groups. The combination of anticholinesterase, neuroprotective, and antioxidant properties of RA may all be responsible for the observed effects. These results indicate the beneficial effects of subchronic RA administration in passive avoidance learning and memory in control rats as well as in a pharmacological model of cholinergic deficit which continue to expand the knowledge base in creating new treatment strategies for cognition deficits and dementia. Of course, further studies are warranted for clinical use of RA in the management of demented subjects. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Memory and communication support strategies in dementia: effect of a training program for informal caregivers.

PubMed

Liddle, Jacki; Smith-Conway, Erin R; Baker, Rosemary; Angwin, Anthony J; Gallois, Cindy; Copland, David A; Pachana, Nancy A; Humphreys, Michael S; Byrne, Gerard J; Chenery, Helen J

2012-12-01

People with dementia have a range of needs that are met by informal caregivers. A DVD-based training program was developed using research-based strategies for memory and communication in dementia. The effectiveness of the training on the caregiver experience and the well-being of the person with dementia was evaluated. A pre-test/post-test controlled trial was undertaken with caregiver-care-recipient dyads living in the community. Measures of the carers' knowledge of memory and communication strategies, burden, positive perceptions of caregiving, and perceptions of problem behaviors were taken pre- and three months post-intervention. The depression and well-being of the person with dementia were also evaluated. Satisfaction with the training and feedback were measured. Twenty-nine dyads (13 training group, 16 control group) participated. Bonferroni's correction was made to adjust for multiple comparisons, setting α at 0.00385. A significant improvement was found in caregivers' knowledge for the training group compared to the control group (p = 0.0011). The training group caregivers reported a reduction in the frequency of care recipient disruptive behaviors (p = 0.028) and increased perceptions of positive aspects of caregiving (p = 0.039), both at a level approaching significance. The training group care recipients had increased frequency of verbally communicated depressive behaviors at a level approaching significance (p = 0.0126). The frequency of observed depressive behaviors was not significantly different between groups. This approach to training for caregivers of people with dementia appears promising for its impact on knowledge and the caregiving experience. Further research could monitor the impact of the training on broader measures of depression and well-being, with a larger sample.

Slowing down after a mild traumatic brain injury: a strategy to improve cognitive task performance?

PubMed

Ozen, Lana J; Fernandes, Myra A

2012-01-01

Long-term persistent attention and memory difficulties following a mild traumatic brain injury (TBI) often go undetected on standard neuropsychological tests, despite complaints by mild TBI individuals. We conducted a visual Repetition Detection working memory task to digits, in which we manipulated task difficulty by increasing cognitive load, to identify subtle deficits long after a mild TBI. Twenty-six undergraduate students with a self-report of one mild TBI, which occurred at least 6 months prior, and 31 non-head-injured controls took part in the study. Participants were not informed until study completion that the study's purpose was to examine cognitive changes following a mild TBI, to reduce the influence of "diagnosis threat" on performance. Neuropsychological tasks did not differentiate the groups, though mild TBI participants reported higher state anxiety levels. On our working memory task, the mild TBI group took significantly longer to accurately detect repeated targets on our task, suggesting that slowed information processing is a long-term consequence of mild TBI. Accuracy was comparable in the low-load condition and, unexpectedly, mild TBI performance surpassed that of controls in the high-load condition. Temporal analysis of target identification suggested a strategy difference between groups: mild TBI participants made a significantly greater number of accurate responses following the target's offset, and significantly fewer erroneous distracter responses prior to target onset, compared with controls. Results suggest that long after a mild TBI, high-functioning young adults invoke a strategy of delaying their identification of targets in order to maintain, and facilitate, accuracy on cognitively demanding tasks. © The Author 2011. Published by Oxford University Press. All rights reserved.

Collective input/output under memory constraints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Yin; Chen, Yong; Zhuang, Yu

2014-12-18

Compared with current high-performance computing (HPC) systems, exascale systems are expected to have much less memory per node, which can significantly reduce necessary collective input/output (I/O) performance. In this study, we introduce a memory-conscious collective I/O strategy that takes into account memory capacity and bandwidth constraints. The new strategy restricts aggregation data traffic within disjointed subgroups, coordinates I/O accesses in intranode and internode layers, and determines I/O aggregators at run time considering memory consumption among processes. We have prototyped the design and evaluated it with commonly used benchmarks to verify its potential. The evaluation results demonstrate that this strategy holdsmore » promise in mitigating the memory pressure, alleviating the contention for memory bandwidth, and improving the I/O performance for projected extreme-scale systems. Given the importance of supporting increasingly data-intensive workloads and projected memory constraints on increasingly larger scale HPC systems, this new memory-conscious collective I/O can have a significant positive impact on scientific discovery productivity.« less

Memory and communication support in dementia: research-based strategies for caregivers.

PubMed

Smith, Erin R; Broughton, Megan; Baker, Rosemary; Pachana, Nancy A; Angwin, Anthony J; Humphreys, Michael S; Mitchell, Leander; Byrne, Gerard J; Copland, David A; Gallois, Cindy; Hegney, Desley; Chenery, Helen J

2011-03-01

Difficulties with memory and communication are prominent and distressing features of dementia which impact on the person with dementia and contribute to caregiver stress and burden. There is a need to provide caregivers with strategies to support and maximize memory and communication abilities in people with dementia. In this project, a team of clinicians, researchers and educators in neuropsychology, psychogeriatrics, nursing and speech pathology translated research-based knowledge from these fields into a program of practical strategies for everyday use by family and professional caregivers. From the available research evidence, the project team identified compensatory or facilitative strategies to assist with common areas of difficulty, and structured these under the mnemonics RECAPS (for memory) and MESSAGE (for communication). This information was adapted for presentation in a DVD-based education program in accordance with known characteristics of effective caregiver education. The resultant DVD comprises (1) information on the nature and importance of memory and communication in everyday life; (2) explanations of common patterns of difficulty and preserved ability in memory and communication across the stages of dementia; (3) acted vignettes demonstrating the strategies, based on authentic samples of speech in dementia; and (4) scenarios to prompt the viewer to consider the benefits of using the strategies. Using a knowledge-translation framework, information and strategies can be provided to family and professional caregivers to help them optimize residual memory and communication in people with dementia. Future development of the materials, incorporating consumer feedback, will focus on methods for enabling wider dissemination.

Age-related changes in strategic variations during arithmetic problem solving: The role of executive control.

PubMed

Hinault, T; Lemaire, P

2016-01-01

In this review, we provide an overview of how age-related changes in executive control influence aging effects in arithmetic processing. More specifically, we consider the role of executive control in strategic variations with age during arithmetic problem solving. Previous studies found that age-related differences in arithmetic performance are associated with strategic variations. That is, when they accomplish arithmetic problem-solving tasks, older adults use fewer strategies than young adults, use strategies in different proportions, and select and execute strategies less efficiently. Here, we review recent evidence, suggesting that age-related changes in inhibition, cognitive flexibility, and working memory processes underlie age-related changes in strategic variations during arithmetic problem solving. We discuss both behavioral and neural mechanisms underlying age-related changes in these executive control processes. © 2016 Elsevier B.V. All rights reserved.

Effects of cognitive control training on the dynamics of (mal)adaptive emotion regulation in daily life.

PubMed

Hoorelbeke, Kristof; Koster, Ernst H W; Demeyer, Ineke; Loeys, Tom; Vanderhasselt, Marie-Anne

2016-10-01

Cognitive control plays a key role in both adaptive emotion regulation, such as positive reappraisal, and maladaptive emotion regulation, such as rumination, with both strategies playing a major role in resilience and well-being. As a result, cognitive control training (CCT) targeting working memory functioning may have the potential to reduce maladaptive emotion regulation and increase adaptive emotion regulation. The current study explored the effects of CCT on positive reappraisal ability in a lab context, and deployment and efficacy of positive appraisal and rumination in daily life. A sample of undergraduates (n = 83) was allocated to CCT or an active control condition, performing 10 online training sessions over a period of 14 days. Effects on regulation of affective states in daily life were assessed using experience sampling over a 7-day posttraining period. Results revealed a positive association between baseline cognitive control and self-reported use of adaptive emotion regulation strategies, whereas maladaptive emotion regulation strategies showed a negative association. CCT showed transfer to working memory functioning on the dual n-back task. Overall, effects of CCT on emotion regulation were limited to reducing deployment of rumination in low positive affective states. However, we did not find beneficial effects on indicators of adaptive emotion regulation. These findings are in line with previous studies targeting maladaptive emotion regulation but suggest limited use in enhancing adaptive emotion regulation in a healthy sample. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Working memory dependence of spatial contextual cueing for visual search.

PubMed

Pollmann, Stefan

2018-05-10

When spatial stimulus configurations repeat in visual search, a search facilitation, resulting in shorter search times, can be observed that is due to incidental learning. This contextual cueing effect appears to be rather implicit, uncorrelated with observers' explicit memory of display configurations. Nevertheless, as I review here, this search facilitation due to contextual cueing depends on visuospatial working memory resources, and it disappears when visuospatial working memory is loaded by a concurrent delayed match to sample task. However, the search facilitation immediately recovers for displays learnt under visuospatial working memory load when this load is removed in a subsequent test phase. Thus, latent learning of visuospatial configurations does not depend on visuospatial working memory, but the expression of learning, as memory-guided search in repeated displays, does. This working memory dependence has also consequences for visual search with foveal vision loss, where top-down controlled visual exploration strategies pose high demands on visuospatial working memory, in this way interfering with memory-guided search in repeated displays. Converging evidence for the contribution of working memory to contextual cueing comes from neuroimaging data demonstrating that distinct cortical areas along the intraparietal sulcus as well as more ventral parieto-occipital cortex are jointly activated by visual working memory and contextual cueing. © 2018 The British Psychological Society.

What success can teach us about failure: the plasma metabolome of older adults with superior memory and lessons for Alzheimer's disease.

PubMed

Mapstone, Mark; Lin, Feng; Nalls, Mike A; Cheema, Amrita K; Singleton, Andrew B; Fiandaca, Massimo S; Federoff, Howard J

2017-03-01

As the world population ages, primary prevention of age-related cognitive decline and disability will become increasingly important. Prevention strategies are often developed from an understanding of disease pathobiology, but models of biological success may provide additional useful insights. Here, we studied 224 older adults, some with superior memory performance (n = 41), some with normal memory performance (n = 109), and some with mild cognitive impairment or Alzheimer's disease (AD; n = 74) to understand metabolomic differences which might inform future interventions to promote cognitive health. Plasma metabolomics revealed significant differential abundance of 12 metabolites in those with superior memory relative to controls (receiver operating characteristic area under the curve [AUC] = 0.89) and the inverse abundance pattern in the mild cognitive impairment, AD (AUC = 1.0) and even preclinical AD groups relative to controls (AUC = 0.97). The 12 metabolites are components of key metabolic pathways regulating oxidative stress, inflammation, and nitric oxide bioavailability. These findings from opposite ends of the cognitive continuum highlight the role of these pathways in superior memory abilities and whose failure may contribute to age-related memory impairment. These pathways may be targeted to promote successful cognitive aging. Copyright © 2016 Elsevier Inc. All rights reserved.

Direct Laser Writing-Based Programmable Transfer Printing via Bioinspired Shape Memory Reversible Adhesive.

PubMed

Huang, Yin; Zheng, Ning; Cheng, Zhiqiang; Chen, Ying; Lu, Bingwei; Xie, Tao; Feng, Xue

2016-12-28

Flexible and stretchable electronics offer a wide range of unprecedented opportunities beyond conventional rigid electronics. Despite their vast promise, a significant bottleneck lies in the availability of a transfer printing technique to manufacture such devices in a highly controllable and scalable manner. Current technologies usually rely on manual stick-and-place and do not offer feasible mechanisms for precise and quantitative process control, especially when scalability is taken into account. Here, we demonstrate a spatioselective and programmable transfer strategy to print electronic microelements onto a soft substrate. The method takes advantage of automated direct laser writing to trigger localized heating of a micropatterned shape memory polymer adhesive stamp, allowing highly controlled and spatioselective switching of the interfacial adhesion. This, coupled to the proper tuning of the stamp properties, enables printing with perfect yield. The wide range adhesion switchability further allows printing of hybrid electronic elements, which is otherwise challenging given the complex interfacial manipulation involved. Our temperature-controlled transfer printing technique shows its critical importance and obvious advantages in the potential scale-up of device manufacturing. Our strategy opens a route to manufacturing flexible electronics with exceptional versatility and potential scalability.

Deficits of long-term memory in ecstasy users are related to cognitive complexity of the task.

PubMed

Brown, John; McKone, Elinor; Ward, Jeff

2010-03-01

Despite animal evidence that methylenedioxymethamphetamine (ecstasy) causes lasting damage in brain regions related to long-term memory, results regarding human memory performance have been variable. This variability may reflect the cognitive complexity of the memory tasks. However, previous studies have tested only a limited range of cognitive complexity. Furthermore, comparisons across different studies are made difficult by regional variations in ecstasy composition and patterns of use. The objective of this study is to evaluate ecstasy-related deficits in human verbal memory over a wide range of cognitive complexity using subjects drawn from a single geographical population. Ecstasy users were compared to non-drug using controls on verbal tasks with low cognitive complexity (stem completion), moderate cognitive complexity (stem-cued recall and word list learning) and high cognitive complexity (California Verbal Learning Test, Verbal Paired Associates and a novel Verbal Triplet Associates test). Where significant differences were found, both groups were also compared to cannabis users. More cognitively complex memory tasks were associated with clearer ecstasy-related deficits than low complexity tasks. In the most cognitively demanding task, ecstasy-related deficits remained even after multiple learning opportunities, whereas the performance of cannabis users approached that of non-drug using controls. Ecstasy users also had weaker deliberate strategy use than both non-drug and cannabis controls. Results were consistent with the proposal that ecstasy-related memory deficits are more reliable on tasks with greater cognitive complexity. This could arise either because such tasks require a greater contribution from the frontal lobe or because they require greater interaction between multiple brain regions.

Effects of Video Game Training on Measures of Selective Attention and Working Memory in Older Adults: Results from a Randomized Controlled Trial.

PubMed

Ballesteros, Soledad; Mayas, Julia; Prieto, Antonio; Ruiz-Marquez, Eloísa; Toril, Pilar; Reales, José M

2017-01-01

Video game training with older adults potentially enhances aspects of cognition that decline with aging and could therefore offer a promising training approach. Although, previous published studies suggest that training can produce transfer, many of them have certain shortcomings. This randomized controlled trial (RCT; Clinicaltrials.gov ID: NCT02796508) tried to overcome some of these limitations by incorporating an active control group and the assessment of motivation and expectations. Seventy-five older volunteers were randomly assigned to the experimental group trained for 16 sessions with non-action video games from Lumosity , a commercial platform (http://www.lumosity.com/) or to an active control group trained for the same number of sessions with simulation strategy games. The final sample included 55 older adults (30 in the experimental group and 25 in the active control group). Participants were tested individually before and after training to assess working memory (WM) and selective attention and also reported their perceived improvement, motivation and engagement. The results showed improved performance across the training sessions. The main results were: (1) the experimental group did not show greater improvements in measures of selective attention and working memory than the active control group (the opposite occurred in the oddball task); (2) a marginal training effect was observed for the N -back task, but not for the Stroop task while both groups improved in the Corsi Blocks task. Based on these results, one can conclude that training with non-action games provide modest benefits for untrained tasks. The effect is not specific for that kind of training as a similar effect was observed for strategy video games. Groups did not differ in motivation, engagement or expectations.

Effects of Video Game Training on Measures of Selective Attention and Working Memory in Older Adults: Results from a Randomized Controlled Trial

PubMed Central

Ballesteros, Soledad; Mayas, Julia; Prieto, Antonio; Ruiz-Marquez, Eloísa; Toril, Pilar; Reales, José M.

2017-01-01

Video game training with older adults potentially enhances aspects of cognition that decline with aging and could therefore offer a promising training approach. Although, previous published studies suggest that training can produce transfer, many of them have certain shortcomings. This randomized controlled trial (RCT; Clinicaltrials.gov ID: NCT02796508) tried to overcome some of these limitations by incorporating an active control group and the assessment of motivation and expectations. Seventy-five older volunteers were randomly assigned to the experimental group trained for 16 sessions with non-action video games from Lumosity, a commercial platform (http://www.lumosity.com/) or to an active control group trained for the same number of sessions with simulation strategy games. The final sample included 55 older adults (30 in the experimental group and 25 in the active control group). Participants were tested individually before and after training to assess working memory (WM) and selective attention and also reported their perceived improvement, motivation and engagement. The results showed improved performance across the training sessions. The main results were: (1) the experimental group did not show greater improvements in measures of selective attention and working memory than the active control group (the opposite occurred in the oddball task); (2) a marginal training effect was observed for the N-back task, but not for the Stroop task while both groups improved in the Corsi Blocks task. Based on these results, one can conclude that training with non-action games provide modest benefits for untrained tasks. The effect is not specific for that kind of training as a similar effect was observed for strategy video games. Groups did not differ in motivation, engagement or expectations. PMID:29163136

The art of war: beyond memory-one strategies in population games.

PubMed

Lee, Christopher; Harper, Marc; Fryer, Dashiell

2015-01-01

We show that the history of play in a population game contains exploitable information that can be successfully used by sophisticated strategies to defeat memory-one opponents, including zero determinant strategies. The history allows a player to label opponents by their strategies, enabling a player to determine the population distribution and to act differentially based on the opponent's strategy in each pairwise interaction. For the Prisoner's Dilemma, these advantages lead to the natural formation of cooperative coalitions among similarly behaving players and eventually to unilateral defection against opposing player types. We show analytically and empirically that optimal play in population games depends strongly on the population distribution. For example, the optimal strategy for a minority player type against a resident TFT population is ALLC, while for a majority player type the optimal strategy versus TFT players is ALLD. Such behaviors are not accessible to memory-one strategies. Drawing inspiration from Sun Tzu's the Art of War, we implemented a non-memory-one strategy for population games based on techniques from machine learning and statistical inference that can exploit the history of play in this manner. Via simulation we find that this strategy is essentially uninvadable and can successfully invade (significantly more likely than a neutral mutant) essentially all known memory-one strategies for the Prisoner's Dilemma, including ALLC (always cooperate), ALLD (always defect), tit-for-tat (TFT), win-stay-lose-shift (WSLS), and zero determinant (ZD) strategies, including extortionate and generous strategies.

The Effect of Teaching Memory Strategies on Iranian EFL Learner's Vocabulary Retention in Terms of Learners' Multiple Intelligences

ERIC Educational Resources Information Center

Abbassi, Adele; Hassaskhah, Jaleh; Tahriri, Abdorreza

2018-01-01

This study targeted to explore the effect of memory strategy on EFL learners' vocabulary retention with a consideration of learners' multiple intelligences. In this study, the memory strategy consisted of three parts of grouping, acronym and images. The participants of this study were 80 male and female EFL learners of intermediate level who…

Free recall in Williams syndrome: is there a dissociation between short- and long-term memory?

PubMed

Brock, Jon; Brown, Gordon D A; Boucher, Jill

2006-04-01

Two experiments used the free recall paradigm to investigate verbal memory abilities in Williams syndrome (WS)--a rare genetic disorder. In an earlier free recall study, Vicari et al. (1996a) reported that, unlike TD controls, children with WS showed a recency effect but failed to show a primacy effect. These authors interpreted their findings as evidence for a dissociation between relatively strong verbal short-term memory and relatively impaired verbal long-term memory. In Experiment 1 of the current study, children with WS and TD controls showed comparable improvements in performance with repeated testing of the same material, indicating similar long-term learning of the test items. Neither group showed evidence of primacy effects. However, the extent of primacy effects in free recall is known to depend on the rehearsal strategy that participants adopt. In Experiment 2, therefore, participants were encouraged to engage in overt cumulative rehearsal. This manipulation resulted in significant and comparable primacy effects in both groups, although neither group demonstrated a significant change in overall performance. There was therefore no evidence from either experiment for a dissociation between short- and long-term verbal memory in WS.

What Causes a Memory Strategy Utilization Deficiency?

ERIC Educational Resources Information Center

Miller, Patricia H.; And Others

1994-01-01

In memory strategy utilization deficiency, a child spontaneously produces an appropriate strategy but receives little or no benefit from it for recall. Three studies suggest two causes: children's failure to relate the task situation to their event knowledge, or to link the strategy to a second strategy, in this case linking a selective attention…

On the Evolutionary Origins of Executive Functions

ERIC Educational Resources Information Center

Ardila, Alfredo

2008-01-01

In this paper it is proposed that the prefrontal lobe participates in two closely related but different executive function abilities: (1) "metacognitive executive functions": problem solving, planning, concept formation, strategy development and implementation, controlling attention, working memory, and the like; that is, executive functions as…

Age-related Associative Memory Deficits in Value-based Remembering: The Contribution of Agenda-based Regulation and Strategy Use

PubMed Central

Ariel, Robert; Price, Jodi; Hertzog, Christopher

2015-01-01

Value-based remembering in free recall tasks may be spared from the typical age-related cognitive decline observed for episodic memory. However, it is unclear whether value-based remembering for associative information is also spared from age-related cognitive decline. The current experiments evaluated the contribution of agenda-based based regulation and strategy use during study to age differences and similarities in value-based remembering of associative information. Participants studied word pairs (Experiments 1-2) or single words (Experiment 2) slated with different point values by moving a mouse controlled cursor to different spatial locations to reveal either items for study or the point value associated with remembering each item. Some participants also provided strategy reports for each item. Younger and older adults allocated greater time to studying high than low valued information, reported using normatively effective encoding strategies to learn high-valued pairs, and avoided study of low-valued pairs. As a consequence, both age groups selectively remembered more high than low-valued items. Despite nearly identical regulatory behavior, an associative memory deficit for older adults was present for high valued pairs. Age differences in value-based remembering did not occur when the materials were word lists. Fluid intelligence also moderated the effectiveness of older adults’ strategy use for high valued pairs (Experiment 2). These results suggest that age differences in associative value-based remembering may be due to some older adults’ gleaning less benefit from using normatively effective encoding strategies rather than age differences in metacognitive self-regulation per se. PMID:26523692

Organizational Learning Strategies and Verbal Memory Deficits in Bipolar Disorder.

PubMed

Nitzburg, George C; Cuesta-Diaz, Armando; Ospina, Luz H; Russo, Manuela; Shanahan, Megan; Perez-Rodriguez, Mercedes; Larsen, Emmett; Mulaimovic, Sandra; Burdick, Katherine E

2017-04-01

Verbal memory (VM) impairment is prominent in bipolar disorder (BD) and is linked to functional outcomes. However, the intricacies of VM impairment have not yet been studied in a large sample of BD patients. Moreover, some have proposed VM deficits that may be mediated by organizational strategies, such as semantic or serial clustering. Thus, the exact nature of VM break-down in BD patients is not well understood, limiting remediation efforts. We investigated the intricacies of VM deficits in BD patients versus healthy controls (HCs) and examined whether verbal learning differences were mediated by use of clustering strategies. The California Verbal Learning Test (CVLT) was administered to 113 affectively stable BD patients and 106 HCs. We compared diagnostic groups on all CVLT indices and investigated whether group differences in verbal learning were mediated by clustering strategies. Although BD patients showed significantly poorer attention, learning, and memory, these indices were only mildly impaired. However, BD patients evidenced poorer use of effective learning strategies and lower recall consistency, with these indices falling in the moderately impaired range. Moreover, relative reliance on semantic clustering fully mediated the relationship between diagnostic category and verbal learning, while reliance on serial clustering partially mediated this relationship. VM deficits in affectively stable bipolar patients were widespread but were generally mildly impaired. However, patients displayed inadequate use of organizational strategies with clear separation from HCs on semantic and serial clustering. Remediation efforts may benefit from education about mnemonic devices or "chunking" techniques to attenuate VM deficits in BD. (JINS, 2017, 23, 358-366).

The suppression effect in visuospatial and verbal working memory span tasks in patients with Alzheimer's disease: a 2-year follow-up study.

PubMed

Elosúa, M Rosa; Peinado, Matías; Contreras, María José; Reales, J Manuel; Montoro, Pedro R

2016-10-01

This study adapted a new task to assess visuospatial and verbal working memory impairments in patients with Alzheimer Disease (AD), including an executive strategy of information suppression. The aim was to examine the visuospatial and verbal difficulties, and additionally to explore the average sex differences, during a 2-year follow-up study. The results indicated that patients with AD showed a significantly lower performance, compared with healthy elderly controls, especially with the suppression of information required in this new task. However, suppression did not lead to a significantly greater decline in the performance of patients when compared with the control group.

Increased numbers of preexisting memory CD8 T cells and decreased T-bet expression can restrain terminal differentiation of secondary effector and memory CD8 T cells.

PubMed

Joshi, Nikhil S; Cui, Weiguo; Dominguez, Claudia X; Chen, Jonathan H; Hand, Timothy W; Kaech, Susan M

2011-10-15

Memory CD8 T cells acquire effector memory cell properties after reinfection and may reach terminally differentiated, senescent states ("Hayflick limit") after multiple infections. The signals controlling this process are not well understood, but we found that the degree of secondary effector and memory CD8 T cell differentiation was intimately linked to the amount of T-bet expressed upon reactivation and preexisting memory CD8 T cell number (i.e., primary memory CD8 T cell precursor frequency) present during secondary infection. Compared with naive cells, memory CD8 T cells were predisposed toward terminal effector (TE) cell differentiation because they could immediately respond to IL-12 and induce T-bet, even in the absence of Ag. TE cell formation after secondary (2°) or tertiary infections was dependent on increased T-bet expression because T-bet(+/-) cells were resistant to these phenotypic changes. Larger numbers of preexisting memory CD8 T cells limited the duration of 2° infection and the amount of IL-12 produced, and consequently, this reduced T-bet expression and the proportion of 2° TE CD8 T cells that formed. Together, these data show that over repeated infections, memory CD8 T cell quality and proliferative fitness is not strictly determined by the number of serial encounters with Ag or cell divisions, but is a function of the CD8 T cell differentiation state, which is genetically controlled in a T-bet-dependent manner. This differentiation state can be modulated by preexisting memory CD8 T cell number and the intensity of inflammation during reinfection. These results have important implications for vaccinations involving prime-boost strategies.

Cognitive training to improve memory in individuals undergoing electroconvulsive therapy: Negative findings.

PubMed

Choi, Jimmy; Wang, Yuanjia; Feng, Tianshu; Prudic, Joan

2017-09-01

Although electroconvulsive therapy (ECT) remains the most effective treatment for severe depression, some patients report persistent memory problems following ECT that impact their quality of life and their willingness to consent to further ECT. While cognitive training has been shown to improve memory performance in various conditions, this approach has never been applied to help patients regain their memory after ECT. In a double-blind study, we tested the efficacy of a new cognitive training program called Memory Training for ECT (Mem-ECT), specifically designed to target anterograde and retrograde memory that can be compromised following ECT. Fifty-nine patients with treatment-resistant depression scheduled to undergo ultra-brief right unilateral ECT were randomly assigned to either: (a) Mem-ECT, (b) active control comprised of nonspecific mental stimulation, or (c) treatment as usual. Participants were evaluated within one week prior to the start of ECT and then again within 2 weeks following the last ECT session. All three groups improved in global function, quality of life, depression, and self-reported memory abilities without significant group differences. While there was a decline in verbal delayed recall and mental status, there was no decline in general retrograde memory or autobiographical memory in any of the groups, with no significant memory or clinical benefit for the Mem-ECT or active control conditions compared to treatment as usual. While we report negative findings, these results continue to promote the much needed discussion on developing effective strategies to minimize the adverse memory side effects of ECT, in hopes it will make ECT a better and more easily tolerated treatment for patients with severe depression who need this therapeutic option. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pharmacological evidence is consistent with a prominent role of spatial memory in complex navigation

PubMed Central

2016-01-01

The ability to learn about the spatial environment plays an important role in navigation, migration, dispersal, and foraging. However, our understanding of both the role of cognition in the development of navigation strategies and the mechanisms underlying these strategies is limited. We tested the hypothesis that complex navigation is facilitated by spatial memory in a population of Chrysemys picta that navigate with extreme precision (±3.5 m) using specific routes that must be learned prior to age three. We used scopolamine, a muscarinic acetylcholine receptor antagonist, to manipulate the cognitive spatial abilities of free-living turtles during naturally occurring overland movements. Experienced adults treated with scopolamine diverted markedly from their precise navigation routes. Naive juveniles lacking experience (and memory) were not affected by scopolamine, and thereby served as controls for perceptual or non-spatial cognitive processes associated with navigation. Further, neither adult nor juvenile movement was affected by methylscopolamine, a form of scopolamine that does not cross the blood–brain barrier, a control for the peripheral effects of scopolamine. Together, these results are consistent with a role of spatial cognition in complex navigation and highlight a cellular mechanism that might underlie spatial cognition. Overall, our findings expand our understanding of the development of complex cognitive abilities of vertebrates and the neurological mechanisms of navigation. PMID:26865305

The Doors and People Test: The Effect of Frontal Lobe Lesions on Recall and Recognition Memory Performance

PubMed Central

2016-01-01

Objective: Memory deficits in patients with frontal lobe lesions are most apparent on free recall tasks that require the selection, initiation, and implementation of retrieval strategies. The effect of frontal lesions on recognition memory performance is less clear with some studies reporting recognition memory impairments but others not. The majority of these studies do not directly compare recall and recognition within the same group of frontal patients, assessing only recall or recognition memory performance. Other studies that do compare recall and recognition in the same frontal group do not consider recall or recognition tests that are comparable for difficulty. Recognition memory impairments may not be reported because recognition memory tasks are less demanding. Method: This study aimed to investigate recall and recognition impairments in the same group of 47 frontal patients and 78 healthy controls. The Doors and People Test was administered as a neuropsychological test of memory as it assesses both verbal and visual recall and recognition using subtests that are matched for difficulty. Results: Significant verbal and visual recall and recognition impairments were found in the frontal patients. Conclusion: These results demonstrate that when frontal patients are assessed on recall and recognition memory tests of comparable difficulty, memory impairments are found on both types of episodic memory test. PMID:26752123

The Doors and People Test: The effect of frontal lobe lesions on recall and recognition memory performance.

PubMed

MacPherson, Sarah E; Turner, Martha S; Bozzali, Marco; Cipolotti, Lisa; Shallice, Tim

2016-03-01

Memory deficits in patients with frontal lobe lesions are most apparent on free recall tasks that require the selection, initiation, and implementation of retrieval strategies. The effect of frontal lesions on recognition memory performance is less clear with some studies reporting recognition memory impairments but others not. The majority of these studies do not directly compare recall and recognition within the same group of frontal patients, assessing only recall or recognition memory performance. Other studies that do compare recall and recognition in the same frontal group do not consider recall or recognition tests that are comparable for difficulty. Recognition memory impairments may not be reported because recognition memory tasks are less demanding. This study aimed to investigate recall and recognition impairments in the same group of 47 frontal patients and 78 healthy controls. The Doors and People Test was administered as a neuropsychological test of memory as it assesses both verbal and visual recall and recognition using subtests that are matched for difficulty. Significant verbal and visual recall and recognition impairments were found in the frontal patients. These results demonstrate that when frontal patients are assessed on recall and recognition memory tests of comparable difficulty, memory impairments are found on both types of episodic memory test. (c) 2016 APA, all rights reserved).

Re-thinking the role of the dorsal striatum in egocentric/response strategy.

PubMed

Botreau, Fanny; Gisquet-Verrier, Pascale

2010-01-01

Rats trained in a dual-solution cross-maze task, which can be solved by place and response strategies, predominantly used a response strategy after extensive training. This paper examines the involvement of the medial and lateral dorsal striatum (mDS and lDS) in the choice of these strategies after partial and extensive training. Our results show that rats with lDS and mDS lesions used mainly a response strategy from the early phase of training. We replicated these unexpected data in rats with lDS lesions and confirmed their tendency to use the response strategy in a modified cross-maze task. When trained in a dual-solution water-maze task, however, control and lesioned rats consistently used a place strategy, demonstrating that lDS and mDS lesioned rats can use a place strategy and that the shift towards a response strategy did not systematically result from extensive training. The present data did not show any clear dissociation between the mDS and lDS in dual solution tasks. They further indicate that the dorsal striatum seems to determine the strategies adopted in a particular context but cannot be considered as a neural support for the response memory system. Accordingly, the role of the lateral and medial part of the dorsal striatum in egocentric/response memory should be reconsidered.

The hard fall effect: high working memory capacity leads to a higher, but less robust short-term memory performance.

PubMed

Thomassin, Noémylle; Gonthier, Corentin; Guerraz, Michel; Roulin, Jean-Luc

2015-01-01

Participants with a high working memory span tend to perform better than low spans in a variety of tasks. However, their performance is paradoxically more impaired when they have to perform two tasks at once, a phenomenon that could be labeled the "hard fall effect." The present study tested whether this effect exists in a short-term memory task, and investigated the proposal that the effect is due to high spans using efficient facilitative strategies under simple task conditions. Ninety-eight participants performed a spatial short-term memory task under simple and dual task conditions; stimuli presentation times either allowed for the use of complex facilitative strategies or not. High spans outperformed low spans only under simple task conditions when presentation times allowed for the use of facilitative strategies. These results indicate that the hard fall effect exists on a short-term memory task and may be caused by individual differences in strategy use.

The relationships between trait anxiety, place recognition memory, and learning strategy.

PubMed

Hawley, Wayne R; Grissom, Elin M; Dohanich, Gary P

2011-01-20

Rodents learn to navigate mazes using various strategies that are governed by specific regions of the brain. The type of strategy used when learning to navigate a spatial environment is moderated by a number of factors including emotional states. Heightened anxiety states, induced by exposure to stressors or administration of anxiogenic agents, have been found to bias male rats toward the use of a striatum-based stimulus-response strategy rather than a hippocampus-based place strategy. However, no study has yet examined the relationship between natural anxiety levels, or trait anxiety, and the type of learning strategy used by rats on a dual-solution task. In the current experiment, levels of inherent anxiety were measured in an open field and compared to performance on two separate cognitive tasks, a Y-maze task that assessed place recognition memory, and a visible platform water maze task that assessed learning strategy. Results indicated that place recognition memory on the Y-maze correlated with the use of place learning strategy on the water maze. Furthermore, lower levels of trait anxiety correlated positively with better place recognition memory and with the preferred use of place learning strategy. Therefore, competency in place memory and bias in place strategy are linked to the levels of inherent anxiety in male rats. Copyright © 2010 Elsevier B.V. All rights reserved.

Short-term memory coding in children with intellectual disabilities.

PubMed

Henry, Lucy

2008-05-01

To examine visual and verbal coding strategies, I asked children with intellectual disabilities and peers matched for MA and CA to perform picture memory span tasks with phonologically similar, visually similar, long, or nonsimilar named items. The CA group showed effects consistent with advanced verbal memory coding (phonological similarity and word length effects). Neither the intellectual disabilities nor MA groups showed evidence for memory coding strategies. However, children in these groups with MAs above 6 years showed significant visual similarity and word length effects, broadly consistent with an intermediate stage of dual visual and verbal coding. These results suggest that developmental progressions in memory coding strategies are independent of intellectual disabilities status and consistent with MA.

Playing the computer game Tetris prior to viewing traumatic film material and subsequent intrusive memories: Examining proactive interference.

PubMed

James, Ella L; Lau-Zhu, Alex; Tickle, Hannah; Horsch, Antje; Holmes, Emily A

2016-12-01

Visuospatial working memory (WM) tasks performed concurrently or after an experimental trauma (traumatic film viewing) have been shown to reduce subsequent intrusive memories (concurrent or retroactive interference, respectively). This effect is thought to arise because, during the time window of memory consolidation, the film memory is labile and vulnerable to interference by the WM task. However, it is not known whether tasks before an experimental trauma (i.e. proactive interference) would also be effective. Therefore, we tested if a visuospatial WM task given before a traumatic film reduced intrusions. Findings are relevant to the development of preventative strategies to reduce intrusive memories of trauma for groups who are routinely exposed to trauma (e.g. emergency services personnel) and for whom tasks prior to trauma exposure might be beneficial. Participants were randomly assigned to 1 of 2 conditions. In the Tetris condition (n = 28), participants engaged in the computer game for 11 min immediately before viewing a 12-min traumatic film, whereas those in the Control condition (n = 28) had no task during this period. Intrusive memory frequency was assessed using an intrusion diary over 1-week and an Intrusion Provocation Task at 1-week follow-up. Recognition memory for the film was also assessed at 1-week. Compared to the Control condition, participants in the Tetris condition did not report statistically significant difference in intrusive memories of the trauma film on either measure. There was also no statistically significant difference in recognition memory scores between conditions. The study used an experimental trauma paradigm and findings may not be generalizable to a clinical population. Compared to control, playing Tetris before viewing a trauma film did not lead to a statistically significant reduction in the frequency of later intrusive memories of the film. It is unlikely that proactive interference, at least with this task, effectively influences intrusive memory development. WM tasks administered during or after trauma stimuli, rather than proactively, may be a better focus for intrusive memory amelioration. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Strategy combination during execution of memory strategies in young and older adults.

PubMed

Hinault, Thomas; Lemaire, Patrick; Touron, Dayna

2017-05-01

The present study investigated whether people can combine two memory strategies to encode pairs of words more efficiently than with a single strategy, and age-related differences in such strategy combination. Young and older adults were asked to encode pairs of words (e.g., satellite-tunnel). For each item, participants were told to use either the interactive-imagery strategy (e.g., mentally visualising the two words and making them interact), the sentence-generation strategy (i.e., generate a sentence linking the two words), or with strategy combination (i.e., generating a sentence while mentally visualising it). Participants obtained better recall performance on items encoded with strategy combination than on items encoded with interactive-imagery or sentence-generation strategies. Moreover, we found age-related decline in such strategy combination. These findings have important implications to further our understanding of execution of memory strategies, and suggest that strategy combination occurs in a variety of cognitive domains.

Spontaneous strategy use protects against visual working memory deficits in older adults infected with HIV.

PubMed

Woods, Steven Paul; Weber, Erica; Cameron, Marizela V; Dawson, Matthew S; Delano-Wood, Lisa; Bondi, Mark W; Grant, Igor

2010-12-01

Recent studies suggest that older human immunodeficiency virus (HIV)-infected adults are at particular risk for HIV-associated neurocognitive disorders (HAND), including dementia. Deficits in attention/working memory are posited to play a central role in the development of HAND among older adults. The aim of the present study was to examine the possible protective benefits of spontaneous strategy use during a visual working memory task in 46 older and 42 younger adults infected with HIV. Results revealed a significant interaction between age and strategy use, with older adults who used a meta-cognitive strategy demonstrating superior working memory performance versus non-strategy users. This effect was not observed in the younger HIV-infected sample and was not better explained by possible confounding factors, such as education, comorbid medical conditions, or HIV disease severity. Within the older group, strategy use was associated with better executive functions and higher estimated verbal intelligence. Findings from this study suggest that working memory declines in older HIV-infected adults are moderated by the use of higher-level mnemonic strategies and may inform cognitive neurorehabilitation efforts to improve cognitive and everyday functioning outcomes in older persons living with HIV infection.

Age-Related Differences in Recognition Memory for Items and Associations: Contribution of Individual Differences in Working Memory and Metamemory

PubMed Central

Bender, Andrew R.; Raz, Naftali

2012-01-01

Ability to form new associations between unrelated items is particularly sensitive to aging, but the reasons for such differential vulnerability are unclear. In this study, we examined the role of objective and subjective factors (working memory and beliefs about memory strategies) on differential relations of age with recognition of items and associations. Healthy adults (N = 100, age 21 to 79) studied word pairs, completed item and association recognition tests, and rated the effectiveness of shallow (e.g., repetition) and deep (e.g., imagery or sentence generation) encoding strategies. Advanced age was associated with reduced working memory (WM) capacity and poorer associative recognition. In addition, reduced WM capacity, beliefs in the utility of ineffective encoding strategies, and lack of endorsement of effective ones were independently associated with impaired associative memory. Thus, maladaptive beliefs about memory in conjunction with reduced cognitive resources account in part for differences in associative memory commonly attributed to aging. PMID:22251381

How Is Knowledge Generated about Memory Encoding Strategy Effectiveness?

ERIC Educational Resources Information Center

Hertzog, Christopher; Price, Jodi; Dunlosky, John

2008-01-01

This study evaluated how people learn about encoding strategy effectiveness in an associative memory task. Individuals studied two lists of paired associates under instructions to use either a normatively effective strategy (interactive imagery) or a normatively ineffective strategy (rote repetition) for each pair. Questionnaire ratings of imagery…

The Relations between Number Property Strategies, Working Memory, and Multiplication in Elementary Students

ERIC Educational Resources Information Center

Liu, Ru-De; Ding, Yi; Gao, Bing-Cheng; Zhang, Dake

2015-01-01

This study aimed to examine the relations among property strategies, working memory, and multiplication tasks with 101 Chinese fourth-grade students. Two multiplication property strategies (associative and distributive) were compared with no strategy and demonstrated differentiated effects on students' accuracy and reaction time. Associative…

Effects of Induced Memory Strategies on Children's Memory for Pictures and Words.

ERIC Educational Resources Information Center

Filan, Gary; Sullivan, Howard

In this study of children's memory, two types of presentation modes (pictures or words) were crossed with two levels of memory strategy ("make a picture in your mind" or "think of the word") to comprise four treatments: see picture/think picture, see picture/think word, see word/think picture, see word/think word. The study was conducted with 144…

Working Memory Capacity and Recall from Long-Term Memory: Examining the Influences of Encoding Strategies, Study Time Allocation, Search Efficiency, and Monitoring Abilities

ERIC Educational Resources Information Center

Unsworth, Nash

2016-01-01

The relation between working memory capacity (WMC) and recall from long-term memory (LTM) was examined in the current study. Participants performed multiple measures of delayed free recall varying in presentation duration and self-reported their strategy usage after each task. Participants also performed multiple measures of WMC. The results…

Mnemonic Strategies: Creating Schemata for Learning Enhancement

ERIC Educational Resources Information Center

Goll, Paulette S.

2004-01-01

This article investigates the process of remembering and presents techniques to improve memory retention. Examples of association, clustering, imagery, location, mnemonic devices and visualization illustrate strategies that can be used to encode and recall information from the long-term memory. Several memory games offer the opportunity to test…

A kilobyte rewritable atomic memory

NASA Astrophysics Data System (ADS)

Kalff, F. E.; Rebergen, M. P.; Fahrenfort, E.; Girovsky, J.; Toskovic, R.; Lado, J. L.; Fernández-Rossier, J.; Otte, A. F.

2016-11-01

The advent of devices based on single dopants, such as the single-atom transistor, the single-spin magnetometer and the single-atom memory, has motivated the quest for strategies that permit the control of matter with atomic precision. Manipulation of individual atoms by low-temperature scanning tunnelling microscopy provides ways to store data in atoms, encoded either into their charge state, magnetization state or lattice position. A clear challenge now is the controlled integration of these individual functional atoms into extended, scalable atomic circuits. Here, we present a robust digital atomic-scale memory of up to 1 kilobyte (8,000 bits) using an array of individual surface vacancies in a chlorine-terminated Cu(100) surface. The memory can be read and rewritten automatically by means of atomic-scale markers and offers an areal density of 502 terabits per square inch, outperforming state-of-the-art hard disk drives by three orders of magnitude. Furthermore, the chlorine vacancies are found to be stable at temperatures up to 77 K, offering the potential for expanding large-scale atomic assembly towards ambient conditions.

The Effects of Cognitive Reappraisal and Expressive Suppression on Memory of Emotional Pictures.

PubMed

Wang, Yan Mei; Chen, Jie; Han, Ben Yue

2017-01-01

In the field of emotion research, the influence of emotion regulation strategies on memory with emotional materials has been widely discussed in recent years. However, existing studies have focused exclusively on regulating negative emotion but not positive emotion. Therefore, in the present study, we investigated the influence of emotion regulation strategies for positive emotion on memory. One hundred and twenty college students were selected as participants. Emotional pictures (positive, negative and neutral) were selected from Chinese Affective Picture System (CAPS) as experimental materials. We employed a mixed, 4 (emotion regulation strategies: cognitive up-regulation, cognitive down-regulation, expressive suppression, passive viewing) × 3 (emotional pictures: positive, neutral, negative) experimental design. We investigated the influences of different emotion regulation strategies on memory performance, using free recall and recognition tasks with pictures varying in emotional content. The results showed that recognition and free recall memory performance of the cognitive reappraisal groups (up-regulation and down-regulation) were both better than that of the passive viewing group for all emotional pictures. No significant differences were reported in the two kinds of memory scores between the expressive suppression and passive viewing groups. The results also showed that the memory performance with the emotional pictures differed according to the form of memory test. For the recognition test, participants performed better with positive images than with neutral images. Free recall scores with negative images were higher than those with neutral images. These results suggest that both cognitive reappraisal regulation strategies (up-regulation and down-regulation) promoted explicit memories of the emotional content of stimuli, and the form of memory test influenced performance with emotional pictures.

Experimental evolution of insect immune memory versus pathogen resistance.

PubMed

Khan, Imroze; Prakash, Arun; Agashe, Deepa

2017-12-20

Under strong pathogen pressure, insects often evolve resistance to infection. Many insects are also protected via immune memory (immune priming), whereby sublethal exposure to a pathogen enhances survival after secondary infection. Theory predicts that immune memory should evolve when the pathogen is highly virulent, or when pathogen exposure is relatively rare. However, there are no empirical tests of these hypotheses, and the adaptive benefits of immune memory relative to direct resistance against a pathogen are poorly understood. To determine the selective pressures and ecological conditions that shape immune evolution, we imposed strong pathogen selection on flour beetle ( Tribolium castaneum ) populations, infecting them with Bacillus thuringiensis (Bt) for 11 generations. Populations injected first with heat-killed and then live Bt evolved high basal resistance against multiple Bt strains. By contrast, populations injected only with a high dose of live Bt evolved a less effective but strain-specific priming response. Control populations injected with heat-killed Bt did not evolve priming; and in the ancestor, priming was effective only against a low Bt dose. Intriguingly, one replicate population first evolved priming and subsequently evolved basal resistance, suggesting the potential for dynamic evolution of different immune strategies. Our work is the first report showing that pathogens can select for rapid modulation of insect priming ability, allowing hosts to evolve divergent immune strategies (generalized resistance versus specific immune memory) with potentially distinct mechanisms. © 2017 The Author(s).

Verification of immune response optimality through cybernetic modeling.

PubMed

Batt, B C; Kompala, D S

1990-02-09

An immune response cascade that is T cell independent begins with the stimulation of virgin lymphocytes by antigen to differentiate into large lymphocytes. These immune cells can either replicate themselves or differentiate into plasma cells or memory cells. Plasma cells produce antibody at a specific rate up to two orders of magnitude greater than large lymphocytes. However, plasma cells have short life-spans and cannot replicate. Memory cells produce only surface antibody, but in the event of a subsequent infection by the same antigen, memory cells revert rapidly to large lymphocytes. Immunologic memory is maintained throughout the organism's lifetime. Many immunologists believe that the optimal response strategy calls for large lymphocytes to replicate first, then differentiate into plasma cells and when the antigen has been nearly eliminated, they form memory cells. A mathematical model incorporating the concept of cybernetics has been developed to study the optimality of the immune response. Derived from the matching law of microeconomics, cybernetic variables control the allocation of large lymphocytes to maximize the instantaneous antibody production rate at any time during the response in order to most efficiently inactivate the antigen. A mouse is selected as the model organism and bacteria as the replicating antigen. In addition to verifying the optimal switching strategy, results showing how the immune response is affected by antigen growth rate, initial antigen concentration, and the number of antibodies required to eliminate an antigen are included.

Semantic strategy training increases memory performance and brain activity in patients with prefrontal cortex lesions.

PubMed

Miotto, Eliane C; Savage, Cary R; Evans, Jonathan J; Wilson, Barbara A; Martin, Maria G M; Balardin, Joana B; Barros, Fabio G; Garrido, Griselda; Teixeira, Manoel J; Amaro Junior, Edson

2013-03-01

Memory deficit is a frequent cognitive disorder following acquired prefrontal cortex lesions. In the present study, we investigated the brain correlates of a short semantic strategy training and memory performance of patients with distinct prefrontal cortex lesions using fMRI and cognitive tests. Twenty-one adult patients with post-acute prefrontal cortex (PFC) lesions, twelve with left dorsolateral PFC (LPFC) and nine with bilateral orbitofrontal cortex (BOFC) were assessed before and after a short cognitive semantic training using a verbal memory encoding paradigm during scanning and neuropsychological tests outside the scanner. After the semantic strategy training both groups of patients showed significant behavioral improvement in verbal memory recall and use of semantic strategies. In the LPFC group, greater activity in left inferior and medial frontal gyrus, precentral gyrus and insula was found after training. For the BOFC group, a greater activation was found in the left parietal cortex, right cingulated and precuneus after training. The activation of these specific areas in the memory and executive networks following cognitive training was associated to compensatory brain mechanisms and application of the semantic strategy. Copyright © 2012 Elsevier B.V. All rights reserved.

Mood repair via attention refocusing or recall of positive autobiographical memories by adolescents with pediatric-onset major depression.

PubMed

Kovacs, Maria; Yaroslavsky, Ilya; Rottenberg, Jonathan; George, Charles J; Baji, Ildikó; Benák, István; Dochnal, Roberta; Halas, Kitti; Kiss, Enikő; Vetró, Ágnes; Kapornai, Krisztina

2015-10-01

Impaired emotion regulation is increasingly recognized as a core feature of depressive disorders. Indeed, currently and previously depressed adults both report greater problems in attenuating sadness (mood repair) in daily life than healthy controls. In contrast, studies of various strategies to attenuate sad affect have mostly found that currently or previously depressed adults and controls were similarly successful at mood repair in the laboratory. But few studies have examined mood repair among depression-prone youths or the effects of trait characteristics on mood repair outcomes in the laboratory. Adolescents, whose first episode of major depressive disorder (MDD) had onset at age 9, on average (probands), and were either in remission or depressed, and control peers, watched a sad film clip. Then, they were instructed to engage in refocusing attention (distraction) or recalling happy memories. Using affect ratings provided by the youths, we tested two developmentally informed hypotheses about whether the subject groups would be similarly able to attenuate sadness via the two mood repair strategies. We also explored if self-reported habitual (trait) mood repair influenced laboratory performance. Contrary to expectations, attention refocusing and recall of happy memories led to comparable mood benefits across subjects. Control adolescents reported significantly greater reductions in sadness than did depressed (Cohen's d = .48) or remitted (Cohen's d = .32) probands, regardless of mood repair strategy, while currently depressed probands remained the saddest after mood repair. Habitual mood repair styles moderated the effects of instructed (state) mood repair in the laboratory. Whether depressed or in remission, adolescents with MDD histories are not as efficient at mood repair in the laboratory as controls. But proband-control group differences in mood repair outcomes were modest in scope, suggesting that the abilities that subserve affect regulation have been preserved in probands to some degree. Further information about the nature of mood repair problems among youths with depression histories would help to better understand the clinical course of MDD and to design personalized interventions for depression. © 2015 Association for Child and Adolescent Mental Health.

Mood repair via attention refocusing or recall of positive autobiographical memories by adolescents with pediatric onset major depression

PubMed Central

Kovacs, Maria; Yaroslavsky, Ilya; Rottenberg, Jonathan; George, Charles J.; Baji, Ildikó; Benák, István; Dochnal, Roberta; Halas, Kitti; Kiss, Enikő; Vetró, Ágnes; Kapornai, Krisztina

2014-01-01

Background Impaired emotion regulation is increasingly recognized as a core feature of depressive disorders. Indeed, currently and previously depressed adults both report greater problems in attenuating sadness (mood repair) in daily life than healthy controls. In contrast, studies of various strategies to attenuate sad affect have mostly found that currently or previously depressed adults and controls were similarly successful at mood repair in the laboratory. But few studies have examined mood repair among depression-prone youths or the effects of trait characteristics on mood repair outcomes in the laboratory. Methods Adolescents, whose first episode of major depressive disorder (MDD) had onset at age 9, on average (probands), and were either in remission or depressed, and control peers, watched a sad film clip. Then, they were instructed to engage in re-focusing attention (distraction) or recalling happy memories. Using affect ratings provided by the youths, we tested two developmentally informed hypotheses about whether the subject groups would be similarly able to attenuate sadness via the two mood repair strategies. We also explored if self-reported habitual (trait) mood repair influenced laboratory performance. Results Contrary to expectations, attention re-focusing and recall of happy memories led to comparable mood benefits across subjects. Control adolescents reported significantly greater reductions in sadness than did depressed (Cohen’s d=.48) or remitted (Cohen’s d=.32) probands, regardless of mood repair strategy, while currently depressed probands remained the saddest after mood repair. Habitual mood repair styles moderated the effects of instructed (state) mood repair in the laboratory. Conclusions Whether depressed or in remission, adolescents with MDD histories are not as efficient at mood repair in the laboratory as controls. But proband-control group differences in mood repair outcomes were modest in scope, suggesting that the abilities that subserve affect regulation have been preserved in probands to some degree. Further information about the nature of mood repair problems among youths with depression histories would help to better understand the clinical course of MDD and to design personalized interventions for depression. PMID:25557229

The Effect of Teachers’ Memory-Relevant Language on Children’s Strategy Use and Knowledge

PubMed Central

Grammer, Jennie; Coffman, Jennifer L.; Ornstein, Peter

2014-01-01

Building on longitudinal findings of linkages between aspects of teachers’ language during instruction and children’s use of mnemonic strategies, this investigation was designed to examine experimentally the impact of instruction on memory development. First and second graders (N=54, mean age=7 years) were randomly assigned to a science unit that varied only in teachers’ use of memory-relevant language. Pretest, posttest, and 1-month follow-up assessments revealed that although all participating children learned new information as a result of instruction, those exposed to memory-rich teaching exhibited greater levels of strategic knowledge and engaged in more sophisticated strategy use in a memory task involving instructional content than did students exposed to low-memory instruction. The findings provide support for a causal linkage between teachers’ language and children’s strategic efforts. PMID:23574097

Optimal Foraging in Semantic Memory

ERIC Educational Resources Information Center

Hills, Thomas T.; Jones, Michael N.; Todd, Peter M.

2012-01-01

Do humans search in memory using dynamic local-to-global search strategies similar to those that animals use to forage between patches in space? If so, do their dynamic memory search policies correspond to optimal foraging strategies seen for spatial foraging? Results from a number of fields suggest these possibilities, including the shared…

Effects of Serial Rehearsal Training on Memory Search

ERIC Educational Resources Information Center

McCauley, Charley; And Others

1976-01-01

Half the subjects were trained to use a serial rehearsal strategy during target set storage and half were given no strategy training. The results indicate that the rate of memory search is IQ-related, and that serial rehearsal training facilitates memory search when rehearsal is covert. (Author/BW)

Path Analysis Tests of Theoretical Models of Children's Memory Performance

ERIC Educational Resources Information Center

DeMarie, Darlene; Miller, Patricia H.; Ferron, John; Cunningham, Walter R.

2004-01-01

Path analysis was used to test theoretical models of relations among variables known to predict differences in children's memory--strategies, capacity, and metamemory. Children in kindergarten to fourth grade (chronological ages 5 to 11) performed different memory tasks. Several strategies (i.e., sorting, clustering, rehearsal, and self-testing)…

Changing Conception of Sources of Memory Development. 1985/23.

ERIC Educational Resources Information Center

Chi, Michelene T. H.

1985-01-01

Explanations for memory development have tended to focus on acquistion of general strategies and metaknowledge. Recently, emphasis has been given to the knowledge base as a whole, including general world-knowledge and domain-specific knowledge and procedures. Evidence is presented from the memory development literature showing why strategies and…

What-Where-When Memory and Encoding Strategies in Healthy Aging

ERIC Educational Resources Information Center

Cheke, Lucy G.

2016-01-01

Older adults exhibit disproportionate impairments in memory for item-associations. These impairments may stem from an inability to self-initiate deep encoding strategies. The present study investigates this using the "treasure-hunt task"; a what-where-when style episodic memory test that requires individuals to "hide" items…

Training, transfer, and retention of three-dimensional spatial memory in virtual environments

NASA Technical Reports Server (NTRS)

Richards, Jason T.; Oman, Charles M.; Shebilske, Wayne L.; Beall, Andrew C.; Liu, Andrew; Natapoff, Alan

2002-01-01

Human orientation requires one to remember and visualize spatial arrangements of landmarks from different perspectives. Astronauts have reported difficulties remembering relationships between environmental landmarks when imagined in arbitrary 3D orientations. The present study investigated the effects of strategy training on humans' 1) ability to infer their orientation from landmarks presented ahead and below, 2) performance when subsequently learning a different array, and 3) retention of configurational knowledge over time. On the first experiment day, 24 subjects were tested in a virtual cubic chamber in which a picture of an animal was drawn on each wall. Through trial-by-trial exposures, they had to memorize the spatial relationships among the six pictures around them and learn to predict the direction to a specific picture when facing any view direction, and in any roll orientation. Half of the subjects ("strategy group") were taught methods for remembering picture groupings, while the remainder received no such training ("control group"). After learning one picture array, the procedure was repeated in a second. Accuracy (% correct) and response time learning curves were measured. Performance for the second array and configurational memory of both arrays were also retested 1, 7, and 30 days later. Results showed that subjects "learned how to learn" this generic 3D spatial memory task regardless of their relative orientation to the environment, that ability and configurational knowledge was retained for at least a month, that figure rotation ability and field independence correlate with performance, and that teaching subjects specific strategies in advance significantly improves performance. Training astronauts to perform a similar generic 3D spatial memory task, and suggesting strategies in advance, may help them orient in three dimensions.

Examining the benefits of combining two learning strategies on recall of functional information in persons with multiple sclerosis.

PubMed

Goverover, Yael; Basso, Michael; Wood, Hali; Chiaravalloti, Nancy; DeLuca, John

2011-12-01

Forgetfulness occurs commonly in people with multiple sclerosis (MS), but few treatments alleviate this problem. This study examined the combined effect of two cognitive rehabilitation strategies to improve learning and memory in MS: self-generation and spaced learning. The hypothesis was that the combination of spaced learning and self-generation would yield better learning and memory recall performance than spaced learning alone. Using a within groups design, 20 participants with MS and 18 healthy controls (HC) were presented with three tasks (learning names, appointment, and object location), each in three learning conditions (Massed, Spaced Learning, and combination of spaced and generated information). Participants were required to recall the information they learned in each of these conditions immediately and 30 min following the initial presentation. The combination of spaced learning and self-generation yielded better recall than did spaced learning alone. In turn, spaced learning resulted in better recall than the massed rehearsal condition. These findings reveal that the combination of these two learning strategies may possess utility as a cognitive rehabilitation strategy.

False memory in aging resulting from self-referential processing.

PubMed

Rosa, Nicole M; Gutchess, Angela H

2013-11-01

Referencing the self is known to enhance accurate memory, but less is known about how the strategy affects false memory, particularly for highly self-relevant information. Because older adults are more prone to false memories, we tested whether self-referencing increased false memories with age. In 2 studies, older and younger adults rated adjectives for self-descriptiveness and later completed a surprise recognition test comprised of words rated previously for self-descriptiveness and novel lure words. Lure words were subsequently rated for self-descriptiveness in order to assess the impact of self-relevance on false memory. Study 2 introduced commonness judgments as a control condition, such that participants completed a recognition test on adjectives rated for commonness in addition to adjectives in the self-descriptiveness condition. Across both studies, findings indicate an increased response bias to self-referencing that increased hit rates for both older and younger adults but also increased false alarms as information became more self-descriptive, particularly for older adults. Although the present study supports previous literature showing a boost in memory for self-referenced information, the increase in false alarms, especially in older adults, highlights the potential for memory errors, particularly for information that is strongly related to the self.

Enhanced old-new recognition and source memory for faces of cooperators and defectors in a social-dilemma game.

PubMed

Bell, Raoul; Buchner, Axel; Musch, Jochen

2010-12-01

A popular assumption in evolutionary psychology is that the human mind comprises specialized cognitive modules for social exchange, including a module that serves to enhance memory for faces of cheaters. In the present study, participants played a trust game with computerized opponents, who either defected or cooperated. In a control condition, no interaction took place. In a surprise memory test, old-new recognition for faces and source memory for the associated cooperative or non-cooperative behavior were assessed. A multinomial model was used to measure old-new discrimination, source memory, and guessing biases separately. Inconsistent with the assumption of a memory mechanism that focuses exclusively on cheating, the present study showed enhanced old-new discrimination and source memory for both cooperators and defectors. Rarity of the behavior strategies within the experiment modulated source memory, but only when the differences in base rates were extreme. The findings can be attributed to a mechanism that focuses on exchange-relevant information and flexibly adapts to take into account the relative significance of this information in the encoding context, which may be more beneficial than focusing exclusively on cheaters. Copyright © 2010 Elsevier B.V. All rights reserved.

Prospective memory training in older adults and its relevance for successful aging.

PubMed

Hering, Alexandra; Rendell, Peter G; Rose, Nathan S; Schnitzspahn, Katharina M; Kliegel, Matthias

2014-11-01

In research on cognitive plasticity, two training approaches have been established: (1) training of strategies to improve performance in a given task (e.g., encoding strategies to improve episodic memory performance) and (2) training of basic cognitive processes (e.g., working memory, inhibition) that underlie a range of more complex cognitive tasks (e.g., planning) to improve both the training target and the complex transfer tasks. Strategy training aims to compensate or circumvent limitations in underlying processes, while process training attempts to augment or to restore these processes. Although research on both approaches has produced some promising findings, results are still heterogeneous and the impact of most training regimes for everyday life is unknown. We, therefore, discuss recent proposals of training regimes aiming to improve prospective memory (i.e., forming and realizing delayed intentions) as this type of complex cognition is highly relevant for independent living. Furthermore, prospective memory is associated with working memory and executive functions and age-related decline is widely reported. We review initial evidence suggesting that both training regimes (i.e., strategy and/or process training) can successfully be applied to improve prospective memory. Conceptual and methodological implications of the findings for research on age-related prospective memory and for training research in general are discussed.

Efficient Machine Learning Approach for Optimizing Scientific Computing Applications on Emerging HPC Architectures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arumugam, Kamesh

Efficient parallel implementations of scientific applications on multi-core CPUs with accelerators such as GPUs and Xeon Phis is challenging. This requires - exploiting the data parallel architecture of the accelerator along with the vector pipelines of modern x86 CPU architectures, load balancing, and efficient memory transfer between different devices. It is relatively easy to meet these requirements for highly structured scientific applications. In contrast, a number of scientific and engineering applications are unstructured. Getting performance on accelerators for these applications is extremely challenging because many of these applications employ irregular algorithms which exhibit data-dependent control-ow and irregular memory accesses. Furthermore,more » these applications are often iterative with dependency between steps, and thus making it hard to parallelize across steps. As a result, parallelism in these applications is often limited to a single step. Numerical simulation of charged particles beam dynamics is one such application where the distribution of work and memory access pattern at each time step is irregular. Applications with these properties tend to present significant branch and memory divergence, load imbalance between different processor cores, and poor compute and memory utilization. Prior research on parallelizing such irregular applications have been focused around optimizing the irregular, data-dependent memory accesses and control-ow during a single step of the application independent of the other steps, with the assumption that these patterns are completely unpredictable. We observed that the structure of computation leading to control-ow divergence and irregular memory accesses in one step is similar to that in the next step. It is possible to predict this structure in the current step by observing the computation structure of previous steps. In this dissertation, we present novel machine learning based optimization techniques to address the parallel implementation challenges of such irregular applications on different HPC architectures. In particular, we use supervised learning to predict the computation structure and use it to address the control-ow and memory access irregularities in the parallel implementation of such applications on GPUs, Xeon Phis, and heterogeneous architectures composed of multi-core CPUs with GPUs or Xeon Phis. We use numerical simulation of charged particles beam dynamics simulation as a motivating example throughout the dissertation to present our new approach, though they should be equally applicable to a wide range of irregular applications. The machine learning approach presented here use predictive analytics and forecasting techniques to adaptively model and track the irregular memory access pattern at each time step of the simulation to anticipate the future memory access pattern. Access pattern forecasts can then be used to formulate optimization decisions during application execution which improves the performance of the application at a future time step based on the observations from earlier time steps. In heterogeneous architectures, forecasts can also be used to improve the memory performance and resource utilization of all the processing units to deliver a good aggregate performance. We used these optimization techniques and anticipation strategy to design a cache-aware, memory efficient parallel algorithm to address the irregularities in the parallel implementation of charged particles beam dynamics simulation on different HPC architectures. Experimental result using a diverse mix of HPC architectures shows that our approach in using anticipation strategy is effective in maximizing data reuse, ensuring workload balance, minimizing branch and memory divergence, and in improving resource utilization.« less

That's a good one! Belief in efficacy of mnemonic strategies contributes to age-related increase in associative memory.

PubMed

Daugherty, Ana M; Ofen, Noa

2015-08-01

The development of associative memory during childhood may be influenced by metacognitive factors. Here, one aspect of metamemory function--belief in strategy efficacy-was tested for a role in the effective use of encoding strategies. A sample of 61 children and adults (8-25 years of age) completed an associative recognition memory test and were assessed on belief in the efficacy of encoding strategies. Independent of age, belief ratings identified two factors: "deep" and "shallow" encoding strategies. Although the strategy factor structure was stable across age, adolescents and adults were more likely to prefer using a deep encoding strategy, whereas children were equally likely to prefer a shallow strategy. Belief ratings of deep encoding strategies increased with age and, critically, accounted for better associative recognition. Copyright © 2015 Elsevier Inc. All rights reserved.

Developmental Improvement in Strategies to Maintain Verbal Information in Working Memory

ERIC Educational Resources Information Center

Oftinger, Anne-Laure; Camos, Valérie

2018-01-01

Although it has been proposed that maintenance of verbal information in adults' working memory relies on two strategies, articulatory rehearsal and attentional refreshing, little is known about the interplay of these strategies in children. To examine strategy changes around the age of seven, children were asked to maintain digits during a…

Search strategy selection in the Morris water maze indicates allocentric map formation during learning that underpins spatial memory formation.

PubMed

Rogers, Jake; Churilov, Leonid; Hannan, Anthony J; Renoir, Thibault

2017-03-01

Using a Matlab classification algorithm, we demonstrate that a highly salient distal cue array is required for significantly increased likelihoods of spatial search strategy selection during Morris water maze spatial learning. We hypothesized that increased spatial search strategy selection during spatial learning would be the key measure demonstrating the formation of an allocentric map to the escape location. Spatial memory, as indicated by quadrant preference for the area of the pool formally containing the hidden platform, was assessed as the main measure that this allocentric map had formed during spatial learning. Our C57BL/6J wild-type (WT) mice exhibit quadrant preference in the highly salient cue paradigm but not the low, corresponding with a 120% increase in the odds of a spatial search strategy selection during learning. In contrast, quadrant preference remains absent in serotonin 1A receptor (5-HT 1A R) knockout (KO) mice, who exhibit impaired search strategy selection during spatial learning. Additionally, we also aimed to assess the impact of the quality of the distal cue array on the spatial learning curves of both latency to platform and path length using mixed-effect regression models and found no significant associations or interactions. In contrast, we demonstrated that the spatial learning curve for search strategy selection was absent during training in the low saliency paradigm. Therefore, we propose that allocentric search strategy selection during spatial learning is the learning parameter in mice that robustly indicates the formation of a cognitive map for the escape goal location. These results also suggest that both latency to platform and path length spatial learning curves do not discriminate between allocentric and egocentric spatial learning and do not reliably predict spatial memory formation. We also show that spatial memory, as indicated by the absolute time in the quadrant formerly containing the hidden platform alone (without reference to the other areas of the pool), was not sensitive to cue saliency or impaired in 5-HT 1A R KO mice. Importantly, in the absence of a search strategy analysis, this suggests that to establish that the Morris water maze has worked (i.e. control mice have formed an allocentric map to the escape goal location), a measure of quadrant preference needs to be reported to establish spatial memory formation. This has implications for studies that claim hippocampal functioning is impaired using latency to platform or path length differences within the existing Morris water maze literature. Copyright © 2016 Elsevier Inc. All rights reserved.

Distinct hippocampal versus frontoparietal-network contributions to retrieval and memory-guided exploration

PubMed Central

Bridge, Donna J.; Cohen, Neal J.; Voss, Joel L.

2017-01-01

Memory can profoundly influence new learning, presumably because memory optimizes exploration of to-be-learned material. Although hippocampus and frontoparietal networks have been implicated in memory-guided exploration, their specific and interactive roles have not been identified. We examined eye movements during fMRI scanning to identify neural correlates of the influences of memory retrieval on exploration and learning. Following retrieval of one object in a multi-object array, viewing was strategically directed away from the retrieved object toward non-retrieved objects, such that exploration was directed towards to-be-learned content. Retrieved objects later served as optimal reminder cues, indicating that exploration caused memory to become structured around the retrieved content. Hippocampal activity was associated with memory retrieval whereas frontoparietal activity varied with strategic viewing patterns deployed following retrieval, thus providing spatiotemporal dissociation of memory retrieval from memory-guided learning strategies. Time-lagged fMRI connectivity analyses indicated that hippocampal activity predicted frontoparietal activity to a greater extent for a condition in which retrieval guided exploration than for a passive control condition in which exploration was not influenced by retrieval. This demonstrates network-level interaction effects specific to influences of memory on strategic exploration. These findings show how memory guides behavior during learning and demonstrate distinct yet interactive hippocampal-frontoparietal roles in implementing strategic exploration behaviors that determine the fate of evolving memory representations. PMID:28471729

Distinct Hippocampal versus Frontoparietal Network Contributions to Retrieval and Memory-guided Exploration.

PubMed

Bridge, Donna J; Cohen, Neal J; Voss, Joel L

2017-08-01

Memory can profoundly influence new learning, presumably because memory optimizes exploration of to-be-learned material. Although hippocampus and frontoparietal networks have been implicated in memory-guided exploration, their specific and interactive roles have not been identified. We examined eye movements during fMRI scanning to identify neural correlates of the influences of memory retrieval on exploration and learning. After retrieval of one object in a multiobject array, viewing was strategically directed away from the retrieved object toward nonretrieved objects, such that exploration was directed toward to-be-learned content. Retrieved objects later served as optimal reminder cues, indicating that exploration caused memory to become structured around the retrieved content. Hippocampal activity was associated with memory retrieval, whereas frontoparietal activity varied with strategic viewing patterns deployed after retrieval, thus providing spatiotemporal dissociation of memory retrieval from memory-guided learning strategies. Time-lagged fMRI connectivity analyses indicated that hippocampal activity predicted frontoparietal activity to a greater extent for a condition in which retrieval guided exploration occurred than for a passive control condition in which exploration was not influenced by retrieval. This demonstrates network-level interaction effects specific to influences of memory on strategic exploration. These findings show how memory guides behavior during learning and demonstrate distinct yet interactive hippocampal-frontoparietal roles in implementing strategic exploration behaviors that determine the fate of evolving memory representations.

Tracking Control of a Magnetic Shape Memory Actuator Using an Inverse Preisach Model with Modified Fuzzy Sliding Mode Control.

PubMed

Lin, Jhih-Hong; Chiang, Mao-Hsiung

2016-08-25

Magnetic shape memory (MSM) alloys are a new class of smart materials with extraordinary strains up to 12% and frequencies in the range of 1 to 2 kHz. The MSM actuator is a potential device which can achieve high performance electromagnetic actuation by using the properties of MSM alloys. However, significant non-linear hysteresis behavior is a significant barrier to control the MSM actuator. In this paper, the Preisach model was used, by capturing experiments from different input signals and output responses, to model the hysteresis of MSM actuator, and the inverse Preisach model, as a feedforward control, provided compensational signals to the MSM actuator to linearize the hysteresis non-linearity. The control strategy for path tracking combined the hysteresis compensator and the modified fuzzy sliding mode control (MFSMC) which served as a path controller. Based on the experimental results, it was verified that a tracking error in the order of micrometers was achieved.

Tracking Control of a Magnetic Shape Memory Actuator Using an Inverse Preisach Model with Modified Fuzzy Sliding Mode Control

PubMed Central

Lin, Jhih-Hong; Chiang, Mao-Hsiung

2016-01-01

Magnetic shape memory (MSM) alloys are a new class of smart materials with extraordinary strains up to 12% and frequencies in the range of 1 to 2 kHz. The MSM actuator is a potential device which can achieve high performance electromagnetic actuation by using the properties of MSM alloys. However, significant non-linear hysteresis behavior is a significant barrier to control the MSM actuator. In this paper, the Preisach model was used, by capturing experiments from different input signals and output responses, to model the hysteresis of MSM actuator, and the inverse Preisach model, as a feedforward control, provided compensational signals to the MSM actuator to linearize the hysteresis non-linearity. The control strategy for path tracking combined the hysteresis compensator and the modified fuzzy sliding mode control (MFSMC) which served as a path controller. Based on the experimental results, it was verified that a tracking error in the order of micrometers was achieved. PMID:27571081

Multipulse addressing of a Raman quantum memory: configurable beam splitting and efficient readout.

PubMed

Reim, K F; Nunn, J; Jin, X-M; Michelberger, P S; Champion, T F M; England, D G; Lee, K C; Kolthammer, W S; Langford, N K; Walmsley, I A

2012-06-29

Quantum memories are vital to the scalability of photonic quantum information processing (PQIP), since the storage of photons enables repeat-until-success strategies. On the other hand, the key element of all PQIP architectures is the beam splitter, which allows us to coherently couple optical modes. Here, we show how to combine these crucial functionalities by addressing a Raman quantum memory with multiple control pulses. The result is a coherent optical storage device with an extremely large time bandwidth product, that functions as an array of dynamically configurable beam splitters, and that can be read out with arbitrarily high efficiency. Networks of such devices would allow fully scalable PQIP, with applications in quantum computation, long distance quantum communications and quantum metrology.

Orbital prefrontal cortex is required for object-in-place scene memory but not performance of a strategy implementation task.

PubMed

Baxter, Mark G; Gaffan, David; Kyriazis, Diana A; Mitchell, Anna S

2007-10-17

The orbital prefrontal cortex is thought to be involved in behavioral flexibility in primates, and human neuroimaging studies have identified orbital prefrontal activation during episodic memory encoding. The goal of the present study was to ascertain whether deficits in strategy implementation and episodic memory that occur after ablation of the entire prefrontal cortex can be ascribed to damage to the orbital prefrontal cortex. Rhesus monkeys were preoperatively trained on two behavioral tasks, the performance of both of which is severely impaired by the disconnection of frontal cortex from inferotemporal cortex. In the strategy implementation task, monkeys were required to learn about two categories of objects, each associated with a different strategy that had to be performed to obtain food reward. The different strategies had to be applied flexibly to optimize the rate of reward delivery. In the scene memory task, monkeys learned 20 new object-in-place discrimination problems in each session. Monkeys were tested on both tasks before and after bilateral ablation of orbital prefrontal cortex. These lesions impaired new scene learning but had no effect on strategy implementation. This finding supports a role for the orbital prefrontal cortex in memory but places limits on the involvement of orbital prefrontal cortex in the representation and implementation of behavioral goals and strategies.

The Relation between Navigation Strategy and Associative Memory: An Individual Differences Approach

ERIC Educational Resources Information Center

Ngo, Chi T.; Weisberg, Steven M.; Newcombe, Nora S.; Olson, Ingrid R.

2016-01-01

Although the hippocampus is implicated in both spatial navigation and associative memory, very little is known about whether individual differences in the 2 domains covary. People who prefer to navigate using a hippocampal-dependent place strategy may show better performance on associative memory tasks than those who prefer a caudate-dependent…

External Memory Aid Preferences of Individuals with Mild Memory Impairments.

PubMed

Lanzi, Alyssa; Wallace, Sarah E; Bourgeois, Michelle S

2018-07-01

Individuals with mild memory impairments often rely on external memory aids (EMAs) to compensate for impaired cognitive abilities and to support independent completion of activities of daily living. These strategies are evidence based; however, professionals have limited knowledge regarding individual preferences and guidance on how to incorporate a person-centered approach into the EMA development phase. The purpose of the current study was to qualitatively investigate individuals' preferences and experiences as they relate to EMAs. Data analysis included (1) evaluation of a posttreatment questionnaire to explore individual strategy preferences following intervention and (2) evaluation of group intervention videos using thematic coding to investigate individuals' experiences with strategies during intervention. Results suggest that older adults with mild memory impairments have unique preferences and experiences, despite limited variability in demographic characteristics. Some themes that emerged included memory ability awareness and attitudes toward technology. Within a person-centered approach, skilled professionals must consider individuals' unique needs, preferences, and experiences when developing strategies throughout the continuum of care to promote sustained EMA use within everyday settings. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Catching the engram: strategies to examine the memory trace.

PubMed

Sakaguchi, Masanori; Hayashi, Yasunori

2012-09-21

Memories are stored within neuronal ensembles in the brain. Modern genetic techniques can be used to not only visualize specific neuronal ensembles that encode memories (e.g., fear, craving) but also to selectively manipulate those neurons. These techniques are now being expanded for the study of various types of memory. In this review, we will summarize the genetic methods used to visualize and manipulate neurons involved in the representation of memory engrams. The methods will help clarify how memory is encoded, stored and processed in the brain. Furthermore, these approaches may contribute to our understanding of the pathological mechanisms associated with human memory disorders and, ultimately, may aid the development of therapeutic strategies to ameliorate these diseases.

Restoring primacy in amnesic free recall: evidence for the recency theory of primacy.

PubMed

Dewar, Michaela; Brown, Gordon D A; Della Sala, Sergio

2011-09-01

Primacy and recency effects at immediate recall are thought to reflect the independent functioning of a long-term memory store (primacy) and a short-term memory store (recency). Key evidence for this theory comes from amnesic patients who show severe long-term memory storage deficits, coupled with profoundly attenuated primacy. Here we challenge this dominant dual-store theory of immediate recall by demonstrating that attenuated primacy in amnesic patients can reflect abnormal working memory rehearsal processes. D.A., a patient with severe amnesia, presented with profoundly attenuated primacy when using her preferred atypical noncumulative rehearsal strategy. In contrast, despite her severe amnesia, she showed normal primacy when her rehearsal was matched with that of controls via an externalized cumulative rehearsal schedule. Our data are in keeping with the "recency theory of primacy" and suggest that primacy at immediate recall is dependent upon medial temporal lobe involvement in cumulative rehearsal rather than long-term memory storage.

Oscillatory dynamics and place field maps reflect hippocampal ensemble processing of sequence and place memory under NMDA receptor control.

PubMed

Cabral, Henrique O; Vinck, Martin; Fouquet, Celine; Pennartz, Cyriel M A; Rondi-Reig, Laure; Battaglia, Francesco P

2014-01-22

Place coding in the hippocampus requires flexible combination of sensory inputs (e.g., environmental and self-motion information) with memory of past events. We show that mouse CA1 hippocampal spatial representations may either be anchored to external landmarks (place memory) or reflect memorized sequences of cell assemblies depending on the behavioral strategy spontaneously selected. These computational modalities correspond to different CA1 dynamical states, as expressed by theta and low- and high-frequency gamma oscillations, when switching from place to sequence memory-based processing. These changes are consistent with a shift from entorhinal to CA3 input dominance on CA1. In mice with a deletion of forebrain NMDA receptors, the ability of place cells to maintain a map based on sequence memory is selectively impaired and oscillatory dynamics are correspondingly altered, suggesting that oscillations contribute to selecting behaviorally appropriate computations in the hippocampus and that NMDA receptors are crucial for this function. Copyright © 2014 Elsevier Inc. All rights reserved.

Targeting latent function: Encouraging effective encoding for successful memory training and transfer

PubMed Central

Lustig, Cindy; Flegal, Kristin E.

2009-01-01

Cognitive training programs for older adults often result in improvements at the group level. However, there are typically large age and individual differences in the size of training benefits. These differences may be related to the degree to which participants implement the processes targeted by the training program. To test this possibility, we tested older adults in a memory-training procedure either under specific strategy instructions designed to encourage semantic, integrative encoding, or in a condition that encouraged time and attention to encoding but allowed participants to choose their own strategy. Both conditions improved the performance of old-old adults relative to an earlier study (Bissig & Lustig, 2007) and reduced self-reports of everyday memory errors. Performance in the strategy-instruction group was related to pre-existing ability, performance in the strategy-choice group was not. The strategy-choice group performed better on a laboratory transfer test of recognition memory, and training performance was correlated with reduced everyday memory errors. Training programs that target latent but inefficiently-used abilities while allowing flexibility in bringing those abilities to bear may best promote effective training and transfer. PMID:19140647

Interfacial interactions and their impact on redox-based resistive switching memories (ReRAMs)

NASA Astrophysics Data System (ADS)

Valov, Ilia

2017-09-01

Redox-based resistive switching memories are nowadays one of the most studied systems in both academia and industrial communities. These devices are scalable down to an almost atomic level and are supposed to be applicable not only for next-generation nonvolatile memories, but also for neuromorphic computing, alternative logic operations and selector devices. The main characteristic feature of these cells is their nano- to sub-nano dimension. This makes the control and especially prediction of their properties very challenging. One of the ways to achieve better understanding and to improve the control of these systems is to study and modify their interfaces. In this review, first the fundamentals will be discussed, as these are essential for understanding which factors control the nanoscale interface properties. Further, different types of interactions at the electrode/solid electrolyte interface reported for ECM- and VCM-type cells will be exemplarily shown. Finally, the strategies and different solutions used to modify the interfaces and overcome the existing problems on the way to more stable and reliable devices will be highlighted.

Reduced prefrontal activation in pediatric patients with obsessive-compulsive disorder during verbal episodic memory encoding.

PubMed

Batistuzzo, Marcelo Camargo; Balardin, Joana Bisol; Martin, Maria da Graça Morais; Hoexter, Marcelo Queiroz; Bernardes, Elisa Teixeira; Borcato, Sonia; Souza, Marina de Marco E; Querido, Cicero Nardini; Morais, Rosa Magaly; de Alvarenga, Pedro Gomes; Lopes, Antonio Carlos; Shavitt, Roseli Gedanke; Savage, Cary R; Amaro, Edson; Miguel, Euripedes C; Polanczyk, Guilherme V; Miotto, Eliane C

2015-10-01

Patients with obsessive-compulsive disorder (OCD) often present with deficits in episodic memory, and there is evidence that these difficulties may be secondary to executive dysfunction, that is, impaired selection and/or application of memory-encoding strategies (mediation hypothesis). Semantic clustering is an effective strategy to enhance encoding of verbal episodic memory (VEM) when word lists are semantically related. Self-initiated mobilization of this strategy has been associated with increased activity in the prefrontal cortex, particularly the orbitofrontal cortex, a key region in the pathophysiology of OCD. We therefore studied children and adolescents with OCD during uncued semantic clustering strategy application in a VEM functional magnetic resonance imaging (fMRI)-encoding paradigm. A total of 25 pediatric patients with OCD (aged 8.1-17.5 years) and 25 healthy controls (HC, aged 8.1-16.9) matched for age, gender, handedness, and IQ were evaluated using a block design VEM paradigm that manipulated semantically related and unrelated words. The semantic clustering strategy score (SCS) predicted VEM performance in HC (p < .001, R(2) = 0.635), but not in patients (p = .099). Children with OCD also presented hypoactivation in the dorsomedial prefrontal cortex (cluster-corrected p < .001). Within-group analysis revealed a negative correlation between Yale-Brown Obsessive Compulsive Scale scores and activation of orbitofrontal cortex in the group with OCD. Finally, a positive correlation between age and SCS was found in HC (p = .001, r = 0.635), but not in patients with OCD (p = .936, r = 0.017). Children with OCD presented altered brain activation during the VEM paradigm and absence of expected correlation between SCS and age, and between SCS and total words recalled. These results suggest that different neural mechanisms underlie self-initiated semantic clustering in OCD. Copyright © 2015 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

The mere exposure effect and recognition depend on the way you look!

PubMed

Willems, Sylvie; Dedonder, Jonathan; Van der Linden, Martial

2010-01-01

In line with Whittlesea and Price (2001), we investigated whether the memory effect measured with an implicit memory paradigm (mere exposure effect) and an explicit recognition task depended on perceptual processing strategies, regardless of whether the task required intentional retrieval. We found that manipulation intended to prompt functional implicit-explicit dissociation no longer had a differential effect when we induced similar perceptual strategies in both tasks. Indeed, the results showed that prompting a nonanalytic strategy ensured performance above chance on both tasks. Conversely, inducing an analytic strategy drastically decreased both explicit and implicit performance. Furthermore, we noted that the nonanalytic strategy involved less extensive gaze scanning than the analytic strategy and that memory effects under this processing strategy were largely independent of gaze movement.

Same task, different strategies: How brain networks can be influenced by memory strategy

PubMed Central

Sanfratello, Lori; Caprihan, Arvind; Stephen, Julia M.; Knoefel, Janice E.; Adair, John C.; Qualls, Clifford; Lundy, S. Laura; Aine, Cheryl J.

2015-01-01

Previous functional neuroimaging studies demonstrated that different neural networks underlie different types of cognitive processing by engaging participants in particular tasks, such as verbal or spatial working memory (WM) tasks. However, we report here that even when a working memory task is defined as verbal or spatial, different types of memory strategies may be employed to complete it, with concomitant variations in brain activity. We developed a questionnaire to characterize the type of strategy used by individual members in a group of 28 young healthy participants (18–25 years) during a spatial WM task. A cluster analysis was performed to differentiate groups. We acquired functional magnetoencephalography (MEG) and structural diffusion tensor imaging (DTI) measures to characterize the brain networks associated with the use of different strategies. We found two types of strategies were utilized during the spatial WM task, a visuospatial and a verbal strategy, and brain regions and timecourses of activation differed between participants who used each. Task performance also varied by type of strategy used, with verbal strategies showing an advantage. In addition, performance on neuropsychological tests (indices from WAIS-IV, REY-D Complex Figure) correlated significantly with fractional anisotropy (FA) measures for the visuospatial strategy group in white matter tracts implicated in other WM/attention studies. We conclude that differences in memory strategy can have a pronounced effect on the locations and timing of brain activation, and that these differences need further investigation as a possible confounding factor for studies using group averaging as a means for summarizing results. PMID:24931401

A finite state, finite memory minimum principle, part 2. [a discussion of game theory, signaling, stochastic processes, and control theory

NASA Technical Reports Server (NTRS)

Sandell, N. R., Jr.; Athans, M.

1975-01-01

The development of the theory of the finite - state, finite - memory (FSFM) stochastic control problem is discussed. The sufficiency of the FSFM minimum principle (which is in general only a necessary condition) was investigated. By introducing the notion of a signaling strategy as defined in the literature on games, conditions under which the FSFM minimum principle is sufficient were determined. This result explicitly interconnects the information structure of the FSFM problem with its optimality conditions. The min-H algorithm for the FSFM problem was studied. It is demonstrated that a version of the algorithm always converges to a particular type of local minimum termed a person - by - person extremal.

Effectiveness and Retention of Teaching Memory Strategy Use to Children with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Bebko, James M.; Rhee, Thomas; Ncube, Busisiwe L.; Dahary, Hadas

2017-01-01

Although low levels of memory strategy use have been found in children with autism spectrum disorders (ASDs), few studies have explored the effectiveness of interventions for improving strategy use with this population. In two studies, we examined the short- and longer term effectiveness of rehearsal strategy training. In Study 1, children with…

Mental Time Travel, Memory and the Social Learning Strategies Tournament

ERIC Educational Resources Information Center

Fogarty, L.; Rendell, L.; Laland, K. N.

2012-01-01

The social learning strategies tournament was an open computer-based tournament investigating the best way to learn in a changing environment. Here we present an analysis of the impact of memory on the ability of strategies entered into the social learning strategies tournament (Rendell, Boyd, et al., 2010) to modify their own behavior to suit a…

From Poor Performance to Success under Stress: Working Memory, Strategy Selection, and Mathematical Problem Solving under Pressure

ERIC Educational Resources Information Center

Beilock, Sian L.; DeCaro, Marci S.

2007-01-01

Two experiments demonstrate how individual differences in working memory (WM) impact the strategies used to solve complex math problems and how consequential testing situations alter strategy use. In Experiment 1, individuals performed multistep math problems under low- or high-pressure conditions and reported their problem-solving strategies.…

Destination memory accuracy and confidence in younger and older adults.

PubMed

Johnson, Tara L; Jefferson, Susan C

2018-01-01

Background/Study Context: Nascent research on destination memory-remembering to whom we tell particular information-suggested that older adults have deficits in destination memory and are more confident on inaccurate responses than younger adults. This study assessed the effects of age, attentional resources, and mental imagery on destination memory accuracy and confidence in younger and older adults. Using computer format, participants told facts to pictures of famous people in one of four conditions (control, self-focus, refocus, imagery). Older adults had lower destination memory accuracy than younger adults, driven by a higher level of false alarms. Whereas younger adults were more confident in accurate answers, older adults were more confident in inaccurate answers. Accuracy across participants was lowest when attention was directed internally but significantly improved when mental imagery was used. Importantly, the age-related differences in false alarms and high-confidence inaccurate answers disappeared when imagery was used. Older adults are more likely than younger adults to commit destination memory errors and are less accurate in related confidence judgments. Furthermore, the use of associative memory strategies may help improve destination memory across age groups, improve the accuracy of confidence judgments in older adults, and decrease age-related destination memory impairment, particularly in young-old adults.

Memory-built-in quantum cloning in a hybrid solid-state spin register

NASA Astrophysics Data System (ADS)

Wang, Weibin; Zu, Chong; He, Li; Zhang, Wengang; Duan, Luming

2015-05-01

As a way to circumvent the quantum no-cloning theorem, approximate quantum cloning protocols have received wide attention with remarkable applications. Copying of quantum states to memory qubits provides an important strategy for eavesdropping in quantum cryptography. We report an experiment that realizes cloning of quantum states from an electron spin to a nuclear spin in a hybrid solid-state spin register with near-optimal fidelity. The nuclear spin provides an ideal memory qubit at room temperature, which stores the cloned quantum states for a millisecond under ambient conditions, exceeding the lifetime of the original quantum state carried by the electron spin by orders of magnitude, and making it an ideal memory qubit. Our experiment is based on control of an individual nitrogen vacancy (NV) center in the diamond, which is a diamond defect that attracts strong interest in recent years with great potential for implementation of quantum information protocols.

Molecular regulation of effector and memory T cell differentiation

PubMed Central

Chang, John T; Wherry, E John; Goldrath, Ananda W

2015-01-01

Immunological memory is a cardinal feature of adaptive immunity and an important goal of vaccination strategies. Here we highlight advances in the understanding of the diverse T lymphocyte subsets that provide acute and long-term protection from infection. These include new insights into the transcription factors, and the upstream ‘pioneering’ factors that regulate their accessibility to key sites of gene regulation, as well as metabolic regulators that contribute to the differentiation of effector and memory subsets; ontogeny and defining characteristics of tissue-resident memory lymphocytes; and origins of the remarkable heterogeneity exhibited by activated T cells. Collectively, these findings underscore progress in delineating the underlying pathways that control diversification in T cell responses but also reveal gaps in the knowledge, as well as the challenges that arise in the application of this knowledge to rationally elicit desired T cell responses through vaccination and immunotherapy. PMID:25396352

How does running memory span work?

PubMed

Bunting, Michael; Cowan, Nelson; Saults, J Scott

2006-10-01

In running memory span, a list ends unpredictably, and the last few items are to be recalled. This task is of increasing importance in recent research. We argue that there are two very different strategies for performing running span tasks: a low-effort strategy in which items are passively held until the list ends, when retrieval into a capacity-limited store takes place; and a higher-effort strategy in which working memory is continually updated using rehearsal processes during the list presentation. In two experiments, we examine the roles of these two strategies and the consequences of two types of interference.

Automatic humidification system to support the assessment of food drying processes

NASA Astrophysics Data System (ADS)

Ortiz Hernández, B. D.; Carreño Olejua, A. R.; Castellanos Olarte, J. M.

2016-07-01

This work shows the main features of an automatic humidification system to provide drying air that match environmental conditions of different climate zones. This conditioned air is then used to assess the drying process of different agro-industrial products at the Automation and Control for Agro-industrial Processes Laboratory of the Pontifical Bolivarian University of Bucaramanga, Colombia. The automatic system allows creating and improving control strategies to supply drying air under specified conditions of temperature and humidity. The development of automatic routines to control and acquire real time data was made possible by the use of robust control systems and suitable instrumentation. The signals are read and directed to a controller memory where they are scaled and transferred to a memory unit. Using the IP address is possible to access data to perform supervision tasks. One important characteristic of this automatic system is the Dynamic Data Exchange Server (DDE) to allow direct communication between the control unit and the computer used to build experimental curves.

Examining the Efficacy of the Modified Story Memory Technique (mSMT) in Persons With TBI Using Functional Magnetic Resonance Imaging (fMRI): The TBI-MEM Trial.

PubMed

Chiaravalloti, Nancy D; Dobryakova, Ekaterina; Wylie, Glenn R; DeLuca, John

2015-01-01

New learning and memory deficits are common following traumatic brain injury (TBI). Yet few studies have examined the efficacy of memory retraining in TBI through the most methodologically vigorous randomized clinical trial. Our previous research has demonstrated that the modified Story Memory Technique (mSMT) significantly improves new learning and memory in multiple sclerosis. The present double-blind, placebo-controlled, randomized clinical trial examined changes in cerebral activation on functional magnetic resonance imaging following mSMT treatment in persons with TBI. Eighteen individuals with TBI were randomly assigned to treatment (n = 9) or placebo (n = 9) groups. Baseline and follow-up functional magnetic resonance imaging was collected during a list-learning task. Significant differences in cerebral activation from before to after treatment were noted in regions belonging to the default mode network and executive control network in the treatment group only. Results are interpreted in light of these networks. Activation differences between the groups likely reflect increased use of strategies taught during treatment. This study demonstrates a significant change in cerebral activation resulting from the mSMT in a TBI sample. Findings are consistent with previous work in multiple sclerosis. Behavioral interventions can show significant changes in the brain, validating clinical utility.

Ecological Relevance Determines Task Priority in Older Adults' Multitasking.

PubMed

Doumas, Michail; Krampe, Ralf Th

2015-05-01

Multitasking is a challenging aspect of human behavior, especially if the concurrently performed tasks are different in nature. Several studies demonstrated pronounced performance decrements (dual-task costs) in older adults for combinations of cognitive and motor tasks. However, patterns of costs among component tasks differed across studies and reasons for participants' resource allocation strategies remained elusive. We investigated young and older adults' multitasking of a working memory task and two sensorimotor tasks, one with low (finger force control) and one with high ecological relevance (postural control). The tasks were performed in single-, dual-, and triple-task contexts. Working memory accuracy was reduced in dual-task contexts with either sensorimotor task and deteriorated further under triple-task conditions. Postural and force performance deteriorated with age and task difficulty in dual-task contexts. However, in the triple-task context with its maximum resource demands, older adults prioritized postural control over both force control and memory. Our results identify ecological relevance as the key factor in older adults' multitasking. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Verbal Processing Speed and Executive Functioning in Long-Term Cochlear Implant Users

PubMed Central

Pisoni, David B.; Kronenberger, William G.

2015-01-01

Purpose The purpose of this study was to report how verbal rehearsal speed (VRS), a form of covert speech used to maintain verbal information in working memory, and another verbal processing speed measure, perceptual encoding speed, are related to 3 domains of executive function (EF) at risk in cochlear implant (CI) users: verbal working memory, fluency-speed, and inhibition-concentration. Method EF, speech perception, and language outcome measures were obtained from 55 prelingually deaf, long-term CI users and matched controls with normal hearing (NH controls). Correlational analyses were used to assess relations between VRS (articulation rate), perceptual encoding speed (digit and color naming), and the outcomes in each sample. Results CI users displayed slower verbal processing speeds than NH controls. Verbal rehearsal speed was related to 2 EF domains in the NH sample but was unrelated to EF outcomes in CI users. Perceptual encoding speed was related to all EF domains in both groups. Conclusions Verbal rehearsal speed may be less influential for EF quality in CI users than for NH controls, whereas rapid automatized labeling skills and EF are closely related in both groups. CI users may develop processing strategies in EF tasks that differ from the covert speech strategies routinely employed by NH individuals. PMID:25320961

Metamemory and aging: Psychometric properties of the Brazilian version of the Multifactorial Memory Questionnaire for elderly

PubMed Central

Simon, Sharon Sanz; Ávila, Renata Thomas; Vieira, Gilson; Bottino, Cássio Machado de Campos

2016-01-01

ABSTRACT Metamemory measures provide subjective memory information and are relevant to investigate memory ability in aging. However, there is a lack of metamemory instruments available in Brazil. Objective: The aim of this study was to examine the psychometric properties of the Brazilian version of the Multifactorial Memory Questionnaire (MMQ), which evaluates different dimensions of subjective memory functioning, such as Feelings, Abilities and Strategies used in everyday life. Methods: The MMQ was translated into Portuguese and administered to 30 Brazilian elderly subjects. The participants underwent cognitive tests, mood scales and metamemory instruments. Results: Analyses revealed good internal consistency (Cronbach's a coefficient ranged from 0.75 to 0.89) and test-retest validity for each MMQ dimensions (positive correlations between two applications ranged from 0.75 to 0.8). Convergent validity evidence for the MMQ was confirmed by significant positive correlations (0.47 to 0.68) with dimensions of the Metamemory in Adulthood scale (MIA) (i.e., the Ability, Control, Self-efficacy and Strategy dimensions). Discriminant validity revealed no associations between the MMQ and cognitive performance, suggesting a weak metamemory-objective memory correspondence. Moreover, there was a negative correlation between MMQ-Ability subscale scores and mood symptoms (-0.63 for anxious symptoms, and -0.54 for depressive symptoms); and the Brazilian MMQ was comparable with MMQ translations to other languages. Conclusion: The Brazilian MMQ exhibits good psychometric properties and appears promising for clinical and research purposes. Additional studies are needed to further examine the psychometric properties of the Brazilian MMQ in a larger sample. PMID:29213442

Phenomenological characterization of memory complaints in preclinical and prodromal Alzheimer's disease.

PubMed

Buckley, Rachel F; Ellis, Kathryn A; Ames, David; Rowe, Christopher C; Lautenschlager, Nicola T; Maruff, Paul; Villemagne, Victor L; Macaulay, S Lance; Szoeke, Cassandra; Martins, Ralph N; Masters, Colin L; Savage, Greg; Rainey-Smith, Stephanie R; Rembach, Alan; Saling, Michael M

2015-07-01

To explore the subjective experience of memory change in groups at risk of dementia (those with mild cognitive impairment MCI or high β-amyloid (Aβ+) burden) to determine the existence of potential phenomenological typologies. We recruited 123 healthy controls (HC) and individuals with MCI from the Australian Imaging, Biomarker and Lifestyle (AIBL) study. Sixty-7 (HC = 47,MCI = 20) had Aβ scans available for analysis. Semistructured interviews were administered, transcribed, and meaningful phrases extracted from transcripts. Twelve themes were defined and compared across diagnostic status and Aβ status. MCI endorsed more complaints of burdensome coping strategies, increasing frequency, sense of predomination, poor contextualization, progression, dependency, impact on affect, and dismissive attitudes. HCAβ+ acknowledged a progressive memory decline compared to HCAβ-, while MCIAβ+ expressed more burdensome coping strategies, dismissive attitudes, and dependency comparative to either healthy group. Depression was more likely to be related to complaint themes in HCs, while complaint themes were associated with poorer list-learning performance in individuals with MCI. Complaint themes in those with MCI align with the MCI symptom complex, particularly when accompanied with high Aβ load. Healthy Aβ+ individuals acknowledged progressive memory change, suggesting they are aware of memory changes not yet detectable via neuropsychological measures. Depressive symptomatology associated with HC complaints, suggesting certain themes are affect-driven, while complaints in MCI are associated with organically driven functional impairment. Qualitative analysis of SMCs can inform the earliest clinical manifestations of Alzheimer's disease. Our findings can inform diagnostic approaches to the clinical evaluation of memory complaints in the nondemented elderly. (c) 2015 APA, all rights reserved).

Memory support strategies and bundles: A pathway to improving cognitive therapy for depression?

PubMed

Dong, Lu; Lee, Jason Y; Harvey, Allison G

2017-03-01

Therapist use of memory support (MS) alongside treatment-as-usual, with the goal of enhancing patient recall of treatment contents, has been of recent interest as a novel pathway to improve treatment outcome. The memory support intervention (MSI) involves treatment providers' using 8 specific MS strategies to promote patient memory for treatment. The present study examines to what extent therapist use of MS strategies and bundles improves patient recall of treatment contents and treatment outcome. The data were drawn from a pilot RCT reported elsewhere. Participants were 48 adults (mean age = 44.27 years, 29 females) with major depressive disorder (MDD), randomized to receive 14 sessions of either CT + Memory Support (n = 25) or CT-as-usual (n = 23). Therapist use of MS was coded using the Memory Support Rating Scale. Patient memory and treatment outcomes were assessed at baseline, midtreatment (patient recall only), posttreatment, and 6-month follow-up. Participants in CT + Memory Support received significantly higher amount of MS relative to CT-as-usual. Although not reaching statistical significance, small-to-medium effects were observed between MS strategies and patient recall in the expected direction. Although MS variables were not significantly associated with changes in continuous depressive symptoms, MS was associated with better global functioning. MS also exhibited small to medium effects on treatment response and recurrence in the expected direction but not on remission, though these effects did not reach statistical significance. These results provide initial empirical evidence supporting an active method for therapists to implement MS strategies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Understanding women's experience of memory over the menopausal transition: subjective and objective memory in pre-, peri-, and postmenopausal women.

PubMed

Unkenstein, Anne E; Bryant, Christina A; Judd, Fiona K; Ong, Ben; Kinsella, Glynda J

2016-12-01

Many women complain of forgetfulness during the menopausal transition. This study aimed to examine women's subjective perception of memory and their objective memory performance across the menopausal transition. One hundred thirty women, aged 40 to 60 years were recruited from outpatient Menopause and Gynaecological clinics at the Royal Women's Hospital, Melbourne. Women were divided into menopausal stage groups according to the Stages of Reproductive Aging Workshop criteria based on menstrual patterns. All women completed self-report measures of depressive, anxiety, vasomotor, and sleep symptoms; attitude to menopause; and various aspects of memory, including memory contentment, frequency of forgetting, sense of control over memory, and use of memory strategies. Women also completed a comprehensive neuropsychological evaluation assessing memory and executive function. Comprehensive neuropsychological assessment showed no difference between premenopausal (n = 36), perimenopausal (n = 54), and postmenopausal (n = 40) groups in performance on memory and executive tasks. Perimenopausal women, however, reported significantly more frequent forgetting (η = 0.09, P < 0.01) and less contentment with their memory (η = 0.08, P < 0.01) than pre- and postmenopausal women. Although no impairment was observed in neuropsychological performance, when compared with pre- and postmenopausal women, perimenopausal women were more likely to be dissatisfied with their memory. During the menopausal transition women with a more negative attitude to menopause and more intense depressive, anxiety, vasomotor, and sleep symptoms are more vulnerable to feeling less content with their memory.

Effects of cacheing on multitasking efficiency and programming strategy on an ELXSI 6400

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montry, G.R.; Benner, R.E.

1985-12-01

The impact of a cache/shared memory architecture, and, in particular, the cache coherency problem, upon concurrent algorithm and program development is discussed. In this context, a simple set of programming strategies are proposed which streamline code development and improve code performance when multitasking in a cache/shared memory or distributed memory environment.

The Use of Organizational Strategies to Improve Memory for Prose Passages.

ERIC Educational Resources Information Center

Byrd, Mark

1986-01-01

Examined effects of enforced organizational strategies on the memory of older adults for textual material. Young and old adults sorted scrambled sentences of a prose passage into the correct order. When older adults were required to make an in-depth analysis to sort material, their incidental memory for textual information was approximately equal…

Effects of the Knowledge Base on Children's Rehearsal and Organizational Strategies.

ERIC Educational Resources Information Center

Ornstein, Peter A.; Naus, Mary J.

In addition to the important role of memory strategies in mediating age changes in recall performance, it is clear that the permanent memory system (or information available in the knowledge base) exerts a significant influence on the acquisition and retention of information. Age changes in memory performance will be fully understood only through…

Comparing reactive and memory-one strategies of direct reciprocity

NASA Astrophysics Data System (ADS)

Baek, Seung Ki; Jeong, Hyeong-Chai; Hilbe, Christian; Nowak, Martin A.

2016-05-01

Direct reciprocity is a mechanism for the evolution of cooperation based on repeated interactions. When individuals meet repeatedly, they can use conditional strategies to enforce cooperative outcomes that would not be feasible in one-shot social dilemmas. Direct reciprocity requires that individuals keep track of their past interactions and find the right response. However, there are natural bounds on strategic complexity: Humans find it difficult to remember past interactions accurately, especially over long timespans. Given these limitations, it is natural to ask how complex strategies need to be for cooperation to evolve. Here, we study stochastic evolutionary game dynamics in finite populations to systematically compare the evolutionary performance of reactive strategies, which only respond to the co-player’s previous move, and memory-one strategies, which take into account the own and the co-player’s previous move. In both cases, we compare deterministic strategy and stochastic strategy spaces. For reactive strategies and small costs, we find that stochasticity benefits cooperation, because it allows for generous-tit-for-tat. For memory one strategies and small costs, we find that stochasticity does not increase the propensity for cooperation, because the deterministic rule of win-stay, lose-shift works best. For memory one strategies and large costs, however, stochasticity can augment cooperation.

Comparing reactive and memory-one strategies of direct reciprocity

PubMed Central

Baek, Seung Ki; Jeong, Hyeong-Chai; Hilbe, Christian; Nowak, Martin A.

2016-01-01

Direct reciprocity is a mechanism for the evolution of cooperation based on repeated interactions. When individuals meet repeatedly, they can use conditional strategies to enforce cooperative outcomes that would not be feasible in one-shot social dilemmas. Direct reciprocity requires that individuals keep track of their past interactions and find the right response. However, there are natural bounds on strategic complexity: Humans find it difficult to remember past interactions accurately, especially over long timespans. Given these limitations, it is natural to ask how complex strategies need to be for cooperation to evolve. Here, we study stochastic evolutionary game dynamics in finite populations to systematically compare the evolutionary performance of reactive strategies, which only respond to the co-player’s previous move, and memory-one strategies, which take into account the own and the co-player’s previous move. In both cases, we compare deterministic strategy and stochastic strategy spaces. For reactive strategies and small costs, we find that stochasticity benefits cooperation, because it allows for generous-tit-for-tat. For memory one strategies and small costs, we find that stochasticity does not increase the propensity for cooperation, because the deterministic rule of win-stay, lose-shift works best. For memory one strategies and large costs, however, stochasticity can augment cooperation. PMID:27161141

How Metastrategic Considerations Influence the Selection of Frequency Estimation Strategies

ERIC Educational Resources Information Center

Brown, Norman R.

2008-01-01

Prior research indicates that enumeration-based frequency estimation strategies become increasingly common as memory for relevant event instances improves and that moderate levels of context memory are associated with moderate rates of enumeration [Brown, N. R. (1995). Estimation strategies and the judgment of event frequency. Journal of…

Relate it! Objective and subjective evaluation of mediator-based strategies for improving source memory in younger and older adults.

PubMed

Kuhlmann, Beatrice G; Touron, Dayna R

2017-06-01

The present study examined younger and older adults' ability to improve their source memory for different types of sources through imaginal and verbal (sentence) mediators. Younger (18-29 years) and older (60-75 years) adults' strategy use and source memory for either text-type (bold vs italic) or person (woman vs man) sources was assessed; strategy use was either spontaneous or the generation of imaginal mediators was instructed before encoding. Younger and older adults did not differ in spontaneous use of mediator-based strategies; however, older adults generated more images but fewer verbal mediators than younger adults. Participants were able to increase mediator generation when instructed to, resulting in substantial increases in both item and source memory for the instructed conditions in both age groups. Use of verbal mediators was more likely for the more concrete person sources for which source memory was generally better. Importantly, these objective benefits of mediator-based strategies translated into subjective benefits for both younger and older adults: Increased use of either mediator type was correlated with lower experienced task difficulty; the instructions to use imaginal mediators resulted in a significant decrease in difficulty ratings on the group level. Participants were generally able to monitor mediator benefits to both item and source memory and accurately judged mediator strategies (especially imagery) as more effective than repetition; older adults, however, rated all strategies as less effective than younger adults. Implications of these findings, especially for neuropsychological studies on source monitoring, are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Does Cognitive Strategy Training on Word Problems Compensate for Working Memory Capacity in Children with Math Difficulties?

ERIC Educational Resources Information Center

Swanson, H. Lee

2014-01-01

Cognitive strategies are important tools for children with math difficulties (MD) in learning to solve word problems. The effectiveness of strategy training, however, depends on working memory capacity (WMC). Thus, children with MD but with relatively higher WMC are more likely to benefit from strategy training, whereas children with lower WMC may…

Catching the engram: strategies to examine the memory trace

PubMed Central

2012-01-01

Memories are stored within neuronal ensembles in the brain. Modern genetic techniques can be used to not only visualize specific neuronal ensembles that encode memories (e.g., fear, craving) but also to selectively manipulate those neurons. These techniques are now being expanded for the study of various types of memory. In this review, we will summarize the genetic methods used to visualize and manipulate neurons involved in the representation of memory engrams. The methods will help clarify how memory is encoded, stored and processed in the brain. Furthermore, these approaches may contribute to our understanding of the pathological mechanisms associated with human memory disorders and, ultimately, may aid the development of therapeutic strategies to ameliorate these diseases. PMID:22999350

Task-selective memory effects for successfully implemented encoding strategies.

PubMed

Leshikar, Eric D; Duarte, Audrey; Hertzog, Christopher

2012-01-01

Previous behavioral evidence suggests that instructed strategy use benefits associative memory formation in paired associate tasks. Two such effective encoding strategies--visual imagery and sentence generation--facilitate memory through the production of different types of mediators (e.g., mental images and sentences). Neuroimaging evidence suggests that regions of the brain support memory reflecting the mental operations engaged at the time of study. That work, however, has not taken into account self-reported encoding task success (i.e., whether participants successfully generated a mediator). It is unknown, therefore, whether task-selective memory effects specific to each strategy might be found when encoding strategies are successfully implemented. In this experiment, participants studied pairs of abstract nouns under either visual imagery or sentence generation encoding instructions. At the time of study, participants reported their success at generating a mediator. Outside of the scanner, participants further reported the quality of the generated mediator (e.g., images, sentences) for each word pair. We observed task-selective memory effects for visual imagery in the left middle occipital gyrus, the left precuneus, and the lingual gyrus. No such task-selective effects were observed for sentence generation. Intriguingly, activity at the time of study in the left precuneus was modulated by the self-reported quality (vividness) of the generated mental images with greater activity for trials given higher ratings of quality. These data suggest that regions of the brain support memory in accord with the encoding operations engaged at the time of study.

On Rejecting Emotional Lures Created by Phonological Neighborhood Activation

ERIC Educational Resources Information Center

Starns, Jeffrey J.; Cook, Gabriel I.; Hicks, Jason L.; Marsh, Richard L.

2006-01-01

The authors conducted 2 experiments to assess how phonologically related lures are rejected in a false memory paradigm. Some phonological lures were emotional (i.e., taboo) words, and others were not. The authors manipulated the presence of taboo items on the study list and reduced the ability to use controlled rejection strategies by dividing…

Metacognitive Control of the Spacing of Study Repetitions

ERIC Educational Resources Information Center

Benjamin, Aaron S.; Bird, Randy D.

2006-01-01

Rememberers play an active role in learning, not only by committing material more or less faithfully to memory, but also by selecting judicious study strategies (or not). In three experiments, subjects chose whether to mass or space the second presentation of to-be-learned paired-associate terms that were either normatively difficult or easy to…

Rule-Based Categorization Deficits in Focal Basal Ganglia Lesion and Parkinson’s Disease Patients

PubMed Central

Ell, Shawn W.; Weinstein, Andrea; Ivry, Richard B.

2010-01-01

Patients with basal ganglia (BG) pathology are consistently found to be impaired on rule-based category learning tasks in which learning is thought to depend upon the use of an explicit, hypothesis-guided strategy. The factors that influence this impairment remain unclear. Moreover, it remains unknown if the impairments observed in patients with degenerative disorders such as Parkinson's disease (PD) are also observed in those with focal BG lesions. In the present study, we tested patients with either focal BG lesions or PD on two categorization tasks that varied in terms of their demands on selective attention and working memory. Individuals with focal BG lesions were impaired on the task in which working-memory demand was high and performed similarly to healthy controls on the task in which selective-attention demand was high. In contrast, individuals with PD were impaired on both tasks, and accuracy rates did not differ between on- and off-medication states for a subset of patients who were also tested after abstaining from dopaminergic medication. Quantitative, model-based analyses attributed the performance deficit for both groups in the task with high working-memory demand to the utilization of suboptimal strategies, whereas the PD-specific impairment on the task with high selective-attention demand was driven by the inconsistent use of an optimal strategy. These data suggest that the demands on selective attention and working memory affect the presence of impairment in patients with focal BG lesions and the nature of the impairment in patients with PD. PMID:20600196

Increasing Memory Self-Efficacy and Strategy Use in Hispanic Elders.

PubMed

McDougall, Graham J

1998-01-01

This study tested the effects of a 4-week, nine-session group intervention taught in Spanish to Hispanic older adults entitled "Quieres Mejorar Tu Memoria" (Do you wish to improve your memory?). The program was based on Bandura's self-efficacy theory and was designed to increase memory self-efficacy and strategy use. A total of 33 older adults attending a senior center (mean--age = 69 years; education = 5 years; MMSE = 25) participated in the study. A booster session and a post-test were given at 3 months to the intervention group (n=22). At posttest the intervention reported greater confidence in preventing decline in their memories, and in particular greater use of the internal strategy of elaboration (2.99 vs. 3.41), and the external strategies of list (2.55 vs. 3.38) and note (3.27 vs. 3.75).

Network structures between strategies in iterated prisoners' dilemma games

NASA Astrophysics Data System (ADS)

Kim, Young Jin; Roh, Myungkyoon; Son, Seung-Woo

2014-02-01

We use replicator dynamics to study an iterated prisoners' dilemma game with memory. In this study, we investigate the characteristics of all 32 possible strategies with a single-step memory by observing the results when each strategy encounters another one. Based on these results, we define similarity measures between the 32 strategies and perform a network analysis of the relationship between the strategies by constructing a strategies network. Interestingly, we find that a win-lose circulation, like rock-paper-scissors, exists between strategies and that the circulation results from one unusual strategy.

Hydrogen gas attenuates sevoflurane neurotoxicity through inhibiting nuclear factor κ-light-chain-enhancer of activated B cells signaling and proinflammatory cytokine release in neonatal rats.

PubMed

Shi, Yiwei; Wang, Gang; Li, Jinyuan; Yu, Wenli

2017-12-06

Anesthesia neurotoxicity in developing brain has gained increasing attention. However, knowledge regarding its mitigating strategies remains scant. Sevoflurane, a commonly used anesthetic, is responsible for learning and memory deficits in neonates. Molecular hydrogen is reported to be a potential neuroprotective agent because of its antioxidative and anti-inflammatory activities. This study aimed to investigate the effect of hydrogen gas on sevoflurane neurotoxicity. The newborn rats were treated with sevoflurane and/or hydrogen gas for 2 h. Spatial recognition memory and fear memory were determined by Y-maze and fear conditioning tests at 10 weeks of age. Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and proinflammatory cytokine levels were detected using western blot analysis. The data showed that the spatial recognition memory and fear memory of the rats treated with sevoflurane decreased compared with the control, and the cognitive function of the rats treated with sevoflurane and hydrogen gas significantly increased in comparison with treatment with sevoflurane alone. Moreover, hydrogen gas suppressed NF-κB phosphorylation and nuclear translocation and reduced the production of interleukin-1β, interleukin-6, and tumor necrosis factor-α following sevoflurane administration. Thus, the results proposed that hydrogen gas might protect against sevoflurane neurotoxicity by inhibiting NF-κB activation and proinflammatory cytokine release, providing a novel therapeutic strategy for anesthesia neurotoxicity.

Event-related brain potentials in memory: correlates of episodic, semantic and implicit memory.

PubMed

Wieser, Stephan; Wieser, Heinz Gregor

2003-06-01

To study cognitive evoked potentials, recorded from scalp EEG and foramen ovale electrodes, during activation of explicit and implicit memory. The subgroups of explicit memory, episodic and semantic memory, are looked at separately. A word-learning task was used, which has been shown to activate hippocampus in H(2)(15)O positron emission tomography studies. Subjects had to study and remember word pairs using different learning strategies: (i) associative word learning (AWL), which activates the episodic memory, (ii) deep single word encoding (DSWE), which activates the semantic memory, and (iii) shallow single word encoding (SSWE), which activates the implicit memory and serves as a baseline. The test included the 'remember/know' paradigm as a behavioural learning control. During the task condition, a 10-20 scalp EEG with additional electrodes in both temporal lobes regions was recorded from 11 healthy volunteers. In one patient with mesiotemporal lobe epilepsy, the EEG was recorded from bilateral foramen ovale electrodes directly from mesial temporal lobe structures. Event-related potentials (ERPs) were calculated off-line and visual and statistical analyses were made. Associative learning strategy produced the best memory performance and the best noetic awareness experience, whereas shallow single word encoding produced the worst performance and the smallest noetic awareness. Deep single word encoding performance was in between. ERPs differed according to the test condition, during both encoding and retrieval, from both the scalp EEG and the foramen ovale electrode recordings. Encoding showed significant differences between the shallow single word encoding (SSWE), which is mainly a function of graphical characteristics, and the other two strategies, deep single word (DSWE) and associative learning (AWL), in which there is a semantic processing of the meaning. ERPs generated by these two categories, which are both functions of explicit memory, differed as well, indicating the presence or the absence of associative binding. Retrieval showed a significant test effect between the word pairs learned by association (AWL) and the ones learned by encoding the words in isolation of each other (DSWE and SSWE). The comparison of the ERPs generated by autonoetic awareness ('remember') and noetic awareness ('know') exhibited a significant test effect as well. The results of behavioural data, in particular that of the 'remember/know' procedure, are evidence that the task paradigm was efficient in activating different kinds of memory. Associative word learning generated a high degree of autonoetic awareness, which is a result of the episodic memory, whereas both kinds of single word learning generated less. AWL, DSWE and SSWE resulted in different electrophysiological correlates, both for encoding as well as retrieval, indicating that different brain structures were activated in different temporal sequence.

Contextual Information Drives the Reconsolidation-Dependent Updating of Retrieved Fear Memories

PubMed Central

Jarome, Timothy J; Ferrara, Nicole C; Kwapis, Janine L; Helmstetter, Fred J

2015-01-01

Stored memories enter a temporary state of vulnerability following retrieval known as ‘reconsolidation', a process that can allow memories to be modified to incorporate new information. Although reconsolidation has become an attractive target for treatment of memories related to traumatic past experiences, we still do not know what new information triggers the updating of retrieved memories. Here, we used biochemical markers of synaptic plasticity in combination with a novel behavioral procedure to determine what was learned during memory reconsolidation under normal retrieval conditions. We eliminated new information during retrieval by manipulating animals' training experience and measured changes in proteasome activity and GluR2 expression in the amygdala, two established markers of fear memory lability and reconsolidation. We found that eliminating new contextual information during the retrieval of memories for predictable and unpredictable fear associations prevented changes in proteasome activity and glutamate receptor expression in the amygdala, indicating that this new information drives the reconsolidation of both predictable and unpredictable fear associations on retrieval. Consistent with this, eliminating new contextual information prior to retrieval prevented the memory-impairing effects of protein synthesis inhibitors following retrieval. These results indicate that under normal conditions, reconsolidation updates memories by incorporating new contextual information into the memory trace. Collectively, these results suggest that controlling contextual information present during retrieval may be a useful strategy for improving reconsolidation-based treatments of traumatic memories associated with anxiety disorders such as post-traumatic stress disorder. PMID:26062788

A novel cognitive intervention for compulsive checking: Targeting maladaptive beliefs about memory.

PubMed

Alcolado, Gillian M; Radomsky, Adam S

2016-12-01

Compulsive checking is one of the most common symptoms of obsessive-compulsive disorder (OCD). Recently it has been proposed that those who check compulsively may believe their memory is poor, rather than having an actual memory impairment. The current study sought to develop and assess a brief cognitive intervention focused on improving maladaptive beliefs about memory, as they pertain to both checking symptoms and memory performance. Participants (N = 24) with a diagnosis of OCD and clinical levels of checking symptomatology were randomly assigned either to receive two weekly 1-hour therapy sessions or to self-monitor during a similar waitlist period. Time spent checking, checking symptoms, maladaptive beliefs about memory, and visuospatial memory were assessed both pre- and post-treatment/waitlist. Results showed that compared to the waitlist condition, individuals in the treatment condition displayed significant decreases in their maladaptive beliefs about memory and checking symptoms from pre- to post-intervention. They also exhibited increased recall performance on a measure of visuospatial memory. Changes in beliefs about memory were predictors of reduced post-intervention checking, but were not predictive of increased post-intervention memory scores. The lack of long term follow-up data and use of a waitlist control leave questions about the stability and specificity of the intervention. Findings provide preliminary evidence that strategies targeting beliefs about memory may be worthy of inclusion in cognitive-behavioural approaches to treating compulsive checking. Copyright © 2015 Elsevier Ltd. All rights reserved.

Coping style and memory specificity in adolescents and adults with histories of child sexual abuse.

PubMed

Harris, Latonya S; Block, Stephanie D; Ogle, Christin M; Goodman, Gail S; Augusti, Else-Marie; Larson, Rakel P; Culver, Michelle A; Pineda, Annarheen R; Timmer, Susan G; Urquiza, Anthony

2016-09-01

Individuals with histories of childhood trauma may adopt a nonspecific memory retrieval strategy to avoid unpleasant and intrusive memories. In a sample of 93 adolescents and adults with or without histories of child sexual abuse (CSA), we tested the hypothesis that nonspecific memory retrieval is related to an individual's general tendency to use avoidant (i.e., distancing) coping as a personal problem-solving or coping strategy, especially in victims of CSA. We also examined age differences and other individual differences (e.g., trauma-related psychopathology) as predictors of nonspecific memories. Distancing coping was significantly associated with less specific autobiographical memory. Younger age, lower vocabulary scores, and non-CSA childhood maltreatment (i.e., physical and emotional abuse) also uniquely predicted less autobiographical memory specificity, whereas trauma-related psychopathology was associated with more specific memory. Implications for the development of autobiographical memory retrieval in the context of coping with childhood maltreatment are discussed.

Children's Use of Semantic Organizational Strategies Is Mediated by Working Memory Capacity

ERIC Educational Resources Information Center

Schleepen, Tamara M. J.; Jonkman, Lisa M.

2012-01-01

In adults, the ability to apply semantic grouping strategies has been found to depend on working memory. To investigate this relation in children, two sort-recall tasks (one without and one with a grouping instruction) were administered to 6-12-year-olds. The role of working memory was examined by means of mediation analyses and by assessing…

Free recall memory performance after aneurysmal subarachnoid hemorrhage.

PubMed

Sheldon, Signy; Macdonald, R Loch; Schweizer, Tom A

2012-03-01

Memory deficits for survivors of aneurysmal subarachnoid hemorrhage (SAH) are common, however, the nature of these deficits is not well understood. In this study, 24 patients with SAH and matched control participants were asked to study six lists containing words from four different categories. For half the lists, the categories were presented together (organized lists). For the remaining lists, the related words were presented randomly to maximize the use of executive processes such as strategy and organization (unorganized lists). Across adjoining lists, there was overlap in the types of categories given, done to promote intrusions. Compared to control participants, SAH patients recalled a similar number of words for the organized lists, but significantly fewer words for the unorganized lists. SAH patients also reported more intrusions than their matched counterparts. Separating patients into anterior communicating artery ruptures (ACoA) and ruptures in other regions, there was a recall deficit only for the unorganized list for those with ACoA ruptures and deficits across both list types for other rupture locations. These results suggest that memory impairment following SAH is likely driven by impairment in the executive components of memory, particularly for those with ACoA ruptures. Such findings may help direct future cognitive-therapeutic programs.

False Memory in Aging Resulting From Self-Referential Processing

PubMed Central

2013-01-01

Objectives. Referencing the self is known to enhance accurate memory, but less is known about how the strategy affects false memory, particularly for highly self-relevant information. Because older adults are more prone to false memories, we tested whether self-referencing increased false memories with age. Method. In 2 studies, older and younger adults rated adjectives for self-descriptiveness and later completed a surprise recognition test comprised of words rated previously for self-descriptiveness and novel lure words. Lure words were subsequently rated for self-descriptiveness in order to assess the impact of self-relevance on false memory. Study 2 introduced commonness judgments as a control condition, such that participants completed a recognition test on adjectives rated for commonness in addition to adjectives in the self-descriptiveness condition. Results. Across both studies, findings indicate an increased response bias to self-referencing that increased hit rates for both older and younger adults but also increased false alarms as information became more self-descriptive, particularly for older adults. Discussion. Although the present study supports previous literature showing a boost in memory for self-referenced information, the increase in false alarms, especially in older adults, highlights the potential for memory errors, particularly for information that is strongly related to the self. PMID:23576449

Effects of Higher-Order Cognitive Strategy Training on Gist-Reasoning and Fact-Learning in Adolescents

PubMed Central

Gamino, Jacquelyn F.; Chapman, Sandra B.; Hull, Elizabeth L.; Lyon, G. Reid

2010-01-01

Improving the reasoning skills of adolescents across the United States has become a major concern for educators and scientists who are dedicated to identifying evidence-based protocols to improve student outcome. This small sample randomized, control pilot study sought to determine the efficacy of higher-order cognitive training on gist-reasoning and fact-learning in an inner-city public middle school. The study compared gist-reasoning and fact-learning performances after training in a smaller sample when tested in Spanish, many of the students’ native language, versus English. The 54 eighth grade students who participated in this pilot study were enroled in an urban middle school, predominantly from lower socio-economic status families, and were primarily of minority descent. The students were randomized into one of three groups, one that learned cognitive strategies promoting abstraction of meaning, a group that learned rote memory strategies, or a control group to ascertain the impact of each program on gist-reasoning and fact-learning from text-based information. We found that the students who had cognitive strategy instruction that entailed abstraction of meaning significantly improved their gist-reasoning and fact-learning ability. The students who learned rote memory strategies significantly improved their fact-learning scores from a text but not gist-reasoning ability. The control group showed no significant change in either gist-reasoning or fact-learning ability. A trend toward significant improvement in overall reading scores for the group that learned to abstract meaning as well as a significant correlation between gist-reasoning ability and the critical thinking on a state-mandated standardized reading test was also found. There were no significant differences between English and Spanish performance of gist-reasoning and fact-learning. Our findings suggest that teaching higher-order cognitive strategies facilitates gist-reasoning ability and student learning. PMID:21833248

Targeting latent function: encouraging effective encoding for successful memory training and transfer.

PubMed

Lustig, Cindy; Flegal, Kristin E

2008-12-01

Cognitive training programs for older adults often result in improvements at the group level. However, there are typically large age and individual differences in the size of training benefits. These differences may be related to the degree to which participants implement the processes targeted by the training program. To test this possibility, we tested older adults in a memory-training procedure either under specific strategy instructions designed to encourage semantic, integrative encoding, or in a condition that encouraged time and attention to encoding but allowed participants to choose their own strategy. Both conditions improved the performance of old-old adults relative to an earlier study (D. Bissig & C. Lustig, 2007) and reduced self-reports of everyday memory errors. Performance in the strategy-instruction group was related to preexisting ability; performance in the strategy?choice group was not. The strategy-choice group performed better on a laboratory transfer test of recognition memory, and training performance was correlated with reduced everyday memory errors. Training programs that target participants' latent but inefficiently used abilities while allowing flexibility in bringing those abilities to bear may best promote effective training and transfer. Copyright (c) 2009 APA, all rights reserved.

Roles of Working Memory Performance and Instructional Strategy in Complex Cognitive Task Performance

ERIC Educational Resources Information Center

Cevik, V.; Altun, A.

2016-01-01

This study aims to investigate how working memory (WM) performances and instructional strategy choices affect learners' complex cognitive task performance in online environments. Three different e-learning environments were designed based on Merrill's (2006a) model of instructional strategies. The lack of experimental research on his framework is…

Working memory capacity and recall from long-term memory: Examining the influences of encoding strategies, study time allocation, search efficiency, and monitoring abilities.

PubMed

Unsworth, Nash

2016-01-01

The relation between working memory capacity (WMC) and recall from long-term memory (LTM) was examined in the current study. Participants performed multiple measures of delayed free recall varying in presentation duration and self-reported their strategy usage after each task. Participants also performed multiple measures of WMC. The results suggested that WMC and LTM recall were related, and part of this relation was due to effective strategy use. However, adaptive changes in strategy use and study time allocation were not related to WMC. Examining multiple variables with structural equation modeling suggested that the relation between WMC and LTM recall was due to variation in effective strategy use, search efficiency, and monitoring abilities. Furthermore, all variables were shown to account for individual differences in LTM recall. These results suggest that the relation between WMC and recall from LTM is due to multiple strategic factors operating at both encoding and retrieval. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Does Strategy Training Reduce Age-Related Deficits in Working Memory?

PubMed Central

Bailey, Heather R.; Dunlosky, John; Hertzog, Christopher

2014-01-01

Background Older adults typically perform worse on measures of working memory (WM) than do young adults; however, age-related differences in WM performance might be reduced if older adults use effective encoding strategies (Bailey, Dunlosky, & Hertzog, 2009). Objective The purpose of the current experiment was to evaluate WM performance after training individuals to use effective encoding strategies. Methods Participants in the training group (older adults: n = 39; young adults: n = 41) were taught about various verbal encoding strategies and their differential effectiveness and were trained to use interactive imagery and sentence generation on a list-learning task. Participants in the control group (older: n=37; young: n=38) completed an equally engaging filler task. All participants completed a pre-training and post-training reading span task, which included self-reported strategy use, as well as two transfer tasks that differed in the affordance to use the trained strategies – a paired-associate recall task and the self-ordered pointing task. Results Both young and older adults were able to use the target strategies on the WM task and showed gains in WM performance after training. The age-related WM deficit was not greatly affected, however, and the training gains did not transfer to the other cognitive tasks. In fact, participants attempted to adapt the trained strategies for a paired-associate recall task, but the increased strategy use did not benefit their performance. Conclusions Strategy training can boost WM performance, and its benefits appear to arise from strategy-specific effects and not from domain-general gains in cognitive ability. PMID:24577079

Evaluating the relationship between white matter integrity, cognition, and varieties of video game learning.

PubMed

Ray, Nicholas R; O'Connell, Margaret A; Nashiro, Kaoru; Smith, Evan T; Qin, Shuo; Basak, Chandramallika

2017-01-01

Many studies are currently researching the effects of video games, particularly in the domain of cognitive training. Great variability exists among video games however, and few studies have attempted to compare different types of video games. Little is known, for instance, about the cognitive processes or brain structures that underlie learning of different genres of video games. To examine the cognitive and neural underpinnings of two different types of game learning in order to evaluate their common and separate correlates, with the hopes of informing future intervention research. Participants (31 younger adults and 31 older adults) completed an extensive cognitive battery and played two different genres of video games, one action game and one strategy game, for 1.5 hours each. DTI scans were acquired for each participant, and regional fractional anisotropy (FA) values were extracted using the JHU atlas. Behavioral results indicated that better performance on tasks of working memory and perceptual discrimination was related to enhanced learning in both games, even after controlling for age, whereas better performance on a perceptual speed task was uniquely related with enhanced learning of the strategy game. DTI results indicated that white matter FA in the right fornix/stria terminalis was correlated with action game learning, whereas white matter FA in the left cingulum/hippocampus was correlated with strategy game learning, even after controlling for age. Although cognition, to a large extent, was a common predictor of both types of game learning, regional white matter FA could separately predict action and strategy game learning. Given the neural and cognitive correlates of strategy game learning, strategy games may provide a more beneficial training tool for adults suffering from memory-related disorders or declines in processing speed, particularly older adults.

Partners or rivals? Strategies for the iterated prisoner's dilemma☆

PubMed Central

Hilbe, Christian; Traulsen, Arne; Sigmund, Karl

2015-01-01

Within the class of memory-one strategies for the iterated Prisoner's Dilemma, we characterize partner strategies, competitive strategies and zero-determinant strategies. If a player uses a partner strategy, both players can fairly share the social optimum; but a co-player preferring an unfair solution will be penalized by obtaining a reduced payoff. A player using a competitive strategy never obtains less than the co-player. A player using a zero-determinant strategy unilaterally enforces a linear relation between the two players' payoffs. These properties hold for every strategy used by the co-player, whether memory-one or not. PMID:26339123

Head west or left, east or right: interactions between memory systems in neurocognitive aging

PubMed Central

Pereira, Inês Tomás; Gallagher, Michela; Rapp, Peter R.

2018-01-01

Cognitive aging is accompanied by decline in multiple domains of memory. Here, we developed a T-maze task that required rats to learn competing hippocampal, and striatal navigation strategies in succession, across days. A final session increased demands on cognitive flexibility and required within-day switching between strategies, emphasizing capacities that engage the prefrontal cortex. Background characterization in young and aged rats used a water maze protocol optimized for individual differences in hippocampal integrity. Consistent with earlier work, young adults acquired place strategies in the T-maze faster than response, whereas the opposite was observed in aged rats with impaired spatial memory. The novel result was that aged animals with preserved spatial memory displayed a qualitatively distinct pattern, acquiring place and response strategies equally rapidly, without disruption when switching between them. Subsequent in situ hybridization for the plasticity-related immediate-early gene Arc revealed that while increasing demands on cognitive flexibility and within-day strategy switching potently engaged the prefrontal cortex in young adult and aged-impaired rats, Arc expression was insensitive in aged rats with normal spatial memory and superior switching abilities. Together, the results indicate that cognitive aging is an emergent property of the interactions between memory systems, and that successful cognitive outcomes reflect a distinct neuroadaptive process rather than a slower rate of aging. PMID:26281759

Combined mnemonic strategy training and high-definition transcranial direct current stimulation for memory deficits in mild cognitive impairment.

PubMed

Hampstead, Benjamin M; Sathian, Krishnankutty; Bikson, Marom; Stringer, Anthony Y

2017-09-01

Memory deficits characterize Alzheimer's dementia and the clinical precursor stage known as mild cognitive impairment. Nonpharmacologic interventions hold promise for enhancing functioning in these patients, potentially delaying functional impairment that denotes transition to dementia. Previous findings revealed that mnemonic strategy training (MST) enhances long-term retention of trained stimuli and is accompanied by increased blood oxygen level-dependent signal in the lateral frontal and parietal cortices as well as in the hippocampus. The present study was designed to enhance MST generalization, and the range of patients who benefit, via concurrent delivery of transcranial direct current stimulation (tDCS). This protocol describes a prospective, randomized controlled, four-arm, double-blind study targeting memory deficits in those with mild cognitive impairment. Once randomized, participants complete five consecutive daily sessions in which they receive either active or sham high definition tDCS over the left lateral prefrontal cortex, a region known to be important for successful memory encoding and that has been engaged by MST. High definition tDCS (active or sham) will be combined with either MST or autobiographical memory recall (comparable to reminiscence therapy). Participants undergo memory testing using ecologically relevant measures and functional magnetic resonance imaging before and after these treatment sessions as well as at a 3-month follow-up. Primary outcome measures include face-name and object-location association tasks. Secondary outcome measures include self-report of memory abilities as well as a spatial navigation task (near transfer) and prose memory (medication instructions; far transfer). Changes in functional magnetic resonance imaging will be evaluated during both task performance and the resting-state using activation and connectivity analyses. The results will provide important information about the efficacy of cognitive and neuromodulatory techniques as well as the synergistic interaction between these promising approaches. Exploratory results will examine patient characteristics that affect treatment efficacy, thereby identifying those most appropriate for intervention.

Recall of vegetable eating affects future predicted enjoyment and choice of vegetables in British University undergraduate students.

PubMed

Robinson, Eric; Blissett, Jackie; Higgs, Suzanne

2011-10-01

Predictions about enjoyment of future experiences are influenced by recalling similar past experiences. However, little is known about the relationship between hedonic memories of past eating episodes and future eating behavior. We investigated recall of previous experiences of eating vegetables and the effect of recall on future predicted liking for and consumption of vegetables. British University undergraduate students were asked to retrieve memories of previous occasions when they ate vegetables and were asked to rate how enjoyable those experiences were (Study 1, n=54). The effect of different types of memory recall (including vegetable eating recall) and visualization of someone else eating vegetables (to control for priming effects) on predicted likelihood of choosing vegetables and predicted enjoyment of eating vegetables was examined (Study 2, n=95). Finally, the effect of recalling vegetable eating memories on actual food choice from a buffet was assessed (Study 3, n=63). It is reported that people recall positive memories of past vegetable consumption (P<0.05) and that reminding people of these experiences results in higher predicted future liking for vegetables (P<0.05) and choice of a larger portion size of vegetables (P<0.05) compared with recall of a personal nonfood memory, a nonvegetable food memory, or visualization of someone else enjoying eating vegetables (increase of approximately 70% in vegetable portion size compared to controls). The results suggest that recall of previous eating experiences could be a potential strategy for altering food choices. Copyright © 2011 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

Evolutionary fate of memory-one strategies in repeated prisoner's dilemma game in structured populations

NASA Astrophysics Data System (ADS)

Liu, Xu-Sheng; Wu, Zhi-Xi; Chen, Michael Z. Q.; Guan, Jian-Yue

2017-07-01

We study evolutionary spatial prisoner's dilemma game involving a one-step memory mechanism of the individuals whenever making strategy updating. In particular, during the process of strategy updating, each individual keeps in mind all the outcome of the action pairs adopted by himself and each of his neighbors in the last interaction, and according to which the individuals decide what actions they will take in the next round. Computer simulation results imply that win-stay-lose-shift like strategy win out of the memory-one strategy set in the stationary state. This result is robust in a large range of the payoff parameter, and does not depend on the initial state of the system. Furthermore, theoretical analysis with mean field and quasi-static approximation predict the same result. Thus, our studies suggest that win-stay-lose-shift like strategy is a stable dominant strategy in repeated prisoner's dilemma game in homogeneous structured populations.

Nanoelectronics from the bottom up.

PubMed

Lu, Wei; Lieber, Charles M

2007-11-01

Electronics obtained through the bottom-up approach of molecular-level control of material composition and structure may lead to devices and fabrication strategies not possible with top-down methods. This review presents a brief summary of bottom-up and hybrid bottom-up/top-down strategies for nanoelectronics with an emphasis on memories based on the crossbar motif. First, we will discuss representative electromechanical and resistance-change memory devices based on carbon nanotube and core-shell nanowire structures, respectively. These device structures show robust switching, promising performance metrics and the potential for terabit-scale density. Second, we will review architectures being developed for circuit-level integration, hybrid crossbar/CMOS circuits and array-based systems, including experimental demonstrations of key concepts such lithography-independent, chemically coded stochastic demultipluxers. Finally, bottom-up fabrication approaches, including the opportunity for assembly of three-dimensional, vertically integrated multifunctional circuits, will be critically discussed.

Ironic effects of emotion suppression when recounting distressing memories.

PubMed

Dalgleish, Tim; Yiend, Jenny; Schweizer, Susanne; Dunn, Barnaby D

2009-10-01

Theories of ironic mental control posit that under conditions in which effortful control is compromised, for example, in laboratory manipulations of mental load or in those suffering from clinical levels of negative affect, attempts to suppress negative emotions can lead to a paradoxical increase in such feelings, relative to conditions in which no suppression is attempted. In line with this, we showed that high negative affect participants, when asked to suppress (downregulate) their negative feelings while writing about a distressing personal memory, exhibited an ironically greater increase in negative emotions compared with a no-instruction condition, in contrast to low negative affect controls who were able to suppress their emotions. Comparable ironic effects were not associated with instructions to experience emotions. This first demonstration of ironic effects of emotion suppression in response to personal material in those with emotional problems sheds light into how certain emotion regulation strategies may maintain and exacerbate such conditions.

The distinctiveness heuristic in false recognition and false recall.

PubMed

McCabe, David P; Smith, Anderson D

2006-07-01

The effects of generative processing on false recognition and recall were examined in four experiments using the Deese-Roediger-McDermott false memory paradigm (Deese, 1959; Roediger & McDermott, 1995). In each experiment, a Generate condition in which subjects generated studied words from audio anagrams was compared to a Control condition in which subjects simply listened to studied words presented normally. Rates of false recognition and false recall were lower for critical lures associated with generated lists, than for critical lures associated with control lists, but only in between-subjects designs. False recall and recognition did not differ when generate and control conditions were manipulated within-subjects. This pattern of results is consistent with the distinctiveness heuristic (Schacter, Israel, & Racine, 1999), a metamemorial decision-based strategy whereby global changes in decision criteria lead to reductions of false memories. This retrieval-based monitoring mechanism appears to operate in a similar fashion in reducing false recognition and false recall.

Variation in Strategy Use Across Measures of Verbal Working Memory

PubMed Central

Morrison, Alexandra B; Rosenbaum, Gail M.; Fair, Damien; Chein, Jason M.

2016-01-01

The working memory (WM) literature contains a number of tasks that vary on dimensions such as when or how memory items are reported. In addition to the ways in which WM tasks are designed to differ, tasks may also diverge according to the strategies participants use during task performance. The present study included seven tasks from the WM literature, each requiring short-term retention of verbal items. Following completion of a small number of trials from each task, individuals completed a self-report questionnaire to identify their primary strategy. Results indicated substantial variation across individuals for a given task, and within the same individual across tasks. Moreover, while direct comparisons between tasks showed that some tasks evinced similar patterns of strategy use despite differing task demands, others showed markedly different patterns of self-reported strategy use. A community detection algorithm aimed at identifying groups of individuals based on their profile of strategic choices revealed unique communities of individuals who are dependent on specific strategies under varying demands. Together, the findings suggest that researchers using common working memory paradigms should very carefully consider the implications of variation in strategy use when interpreting their findings. PMID:27038310

Perirhinal cortical inactivation impairs object-in-place memory and disrupts task-dependent firing in hippocampal CA1, but not in CA3.

PubMed

Lee, Inah; Park, Seong-Beom

2013-01-01

Objects and their locations can associatively define an event and a conjoint representation of object-place can form an event memory. Remembering how to respond to a certain object in a spatial context is dependent on both hippocampus and perirhinal cortex (PER). However, the relative functional contributions of the two regions are largely unknown in object-place associative memory. We investigated the PER influence on hippocampal firing in a goal-directed object-place memory task by comparing the firing patterns of CA1 and CA3 of the dorsal hippocampus between conditions of PER muscimol inactivation and vehicle control infusions. Rats were required to choose one of the two objects in a specific spatial context (regardless of the object positions in the context), which was shown to be dependent on both hippocampus and PER. Inactivation of PER with muscimol (MUS) severely disrupted performance of well-trained rats, resulting in response bias (i.e., choosing any object on a particular side). MUS did not significantly alter the baseline firing rates of hippocampal neurons. We measured the similarity in firing patterns between two trial conditions in which the same target objects were chosen on opposite sides within the same arm [object-in-place (O-P) strategy] and compared the results with the similarity in firing between two trial conditions in which the rat chose any object encountered on a particular side [response-in-place (R-P) strategy]. We found that the similarity in firing patterns for O-P trials was significantly reduced with MUS compared to control conditions (CTs). Importantly, this was largely because MUS injections affected the O-P firing patterns in CA1 neurons, but not in CA3. The results suggest that PER is critical for goal-directed organization of object-place associative memory in the hippocampus presumably by influencing how object information is associated with spatial information in CA1 according to task demand.

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.

Energy-aware Thread and Data Management in Heterogeneous Multi-core, Multi-memory Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Chun-Yi

By 2004, microprocessor design focused on multicore scaling—increasing the number of cores per die in each generation—as the primary strategy for improving performance. These multicore processors typically equip multiple memory subsystems to improve data throughput. In addition, these systems employ heterogeneous processors such as GPUs and heterogeneous memories like non-volatile memory to improve performance, capacity, and energy efficiency. With the increasing volume of hardware resources and system complexity caused by heterogeneity, future systems will require intelligent ways to manage hardware resources. Early research to improve performance and energy efficiency on heterogeneous, multi-core, multi-memory systems focused on tuning a single primitivemore » or at best a few primitives in the systems. The key limitation of past efforts is their lack of a holistic approach to resource management that balances the tradeoff between performance and energy consumption. In addition, the shift from simple, homogeneous systems to these heterogeneous, multicore, multi-memory systems requires in-depth understanding of efficient resource management for scalable execution, including new models that capture the interchange between performance and energy, smarter resource management strategies, and novel low-level performance/energy tuning primitives and runtime systems. Tuning an application to control available resources efficiently has become a daunting challenge; managing resources in automation is still a dark art since the tradeoffs among programming, energy, and performance remain insufficiently understood. In this dissertation, I have developed theories, models, and resource management techniques to enable energy-efficient execution of parallel applications through thread and data management in these heterogeneous multi-core, multi-memory systems. I study the effect of dynamic concurrent throttling on the performance and energy of multi-core, non-uniform memory access (NUMA) systems. I use critical path analysis to quantify memory contention in the NUMA memory system and determine thread mappings. In addition, I implement a runtime system that combines concurrent throttling and a novel thread mapping algorithm to manage thread resources and improve energy efficient execution in multi-core, NUMA systems.« less

Electrical high frequency stimulation in the dorsal striatum: Effects on response learning and on GABA levels in rats.

PubMed

Schumacher, Anett; de Vasconcelos, Anne Pereira; Lecourtier, Lucas; Moser, Andreas; Cassel, Jean-Christophe

2011-09-23

Electrical high frequency stimulation (HFS) has been used to treat various neurological and psychiatric diseases. The striatal area contributes to response learning and procedural memory. Therefore, we investigated the effect of striatal HFS application on procedural/declarative-like memory in rats. All rats were trained in a flooded Double-H maze for three days (4 trials/day) to swim to an escape platform hidden at a constant location. The starting place was the same for all trials. After each training session, HFS of the left dorsal striatum was performed over 4h in alternating 20 min periods (during rest time, 10a.m. to 3p.m.). Nineteen hours after the last HFS and right after a probe trial assessing the rats' strategy (procedural vs. declarative-like memory-based choice), animals were sacrificed and the dorsal striatum was quickly removed. Neurotransmitter levels were measured by HPLC. Stimulated rats did not differ from sham-operated and control rats in acquisition performance, but exhibited altered behavior during the probe trial (procedural memory responses being less frequent than in controls). In stimulated rats, GABA levels were significantly increased in the dorsal striatum on both sides. We suggest that HFS of the dorsal striatum does not alter learning behavior in rats but influences the strategy by which the rats solve the task. Given that the HFS-induced increase of GABA levels was found 19 h after stimulation, it can be assumed that HFS has consequences lasting for several hours and which are functionally significant at a behavioral level, at least under our stimulation (frequency, timing, location, side and strength of stimulation) and testing conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

Independent Contributions of the Central Executive, Intelligence, and In-Class Attentive Behavior to Developmental Change in the Strategies Used to Solve Addition Problems

PubMed Central

Geary, David C.; Hoard, Mary K.; Nugent, Lara

2012-01-01

Children’s (n = 275) use of retrieval, decomposition (e.g., 7 = 4+3, and thus 6+7=6+4+3), and counting to solve additional problems was longitudinally assessed from first to fourth grade, and intelligence, working memory, and in-class attentive behavior was assessed in one or several grades. The goal was to assess the relation between capacity of the central executive component of working memory, controlling for intelligence and in-class attentive behavior, and grade-related changes in children’s use of these strategies. The predictor on intercept effects from multilevel models revealed that children with higher central executive capacity correctly retrieved more facts and used the most sophisticated counting procedure more frequently and accurately than did their lower capacity peers at the beginning of first grade, but the predictor on slope effects indicated that this advantage disappeared (retrieval) or declined in importance (counting) from first to fourth grade. The predictor on slope effects also revealed that from first through fourth grade, children with higher capacity adopted the decomposition strategy more quickly than did other children. The results remained robust with controls for children’s sex, race, school site, speed of encoding Arabic numerals and articulating number words, and mathematics achievement in kindergarten. The results also revealed that intelligence and in-class attentive behavior independently contributed to children’s strategy development. PMID:22698947

Independent contributions of the central executive, intelligence, and in-class attentive behavior to developmental change in the strategies used to solve addition problems.

PubMed

Geary, David C; Hoard, Mary K; Nugent, Lara

2012-09-01

Children's (N=275) use of retrieval, decomposition (e.g., 7=4+3 and thus 6+7=6+4+3), and counting to solve additional problems was longitudinally assessed from first grade to fourth grade, and intelligence, working memory, and in-class attentive behavior was assessed in one or several grades. The goal was to assess the relation between capacity of the central executive component of working memory, controlling for intelligence and in-class attentive behavior, and grade-related changes in children's use of these strategies. The predictor on intercept effects from multilevel models revealed that children with higher central executive capacity correctly retrieved more facts and used the most sophisticated counting procedure more frequently and accurately than their lower capacity peers at the beginning of first grade, but the predictor on slope effects indicated that this advantage disappeared (retrieval) or declined in importance (counting) from first grade to fourth grade. The predictor on slope effects also revealed that from first grade to fourth grade, children with higher capacity adopted the decomposition strategy more quickly than other children. The results remained robust with controls for children's sex, race, school site, speed of encoding Arabic numerals and articulating number words, and mathematics achievement in kindergarten. The results also revealed that intelligence and in-class attentive behavior independently contributed to children's strategy development. Copyright © 2012 Elsevier Inc. All rights reserved.

Category Learning Strategies in Younger and Older Adults: Rule Abstraction and Memorization

PubMed Central

Wahlheim, Christopher N.; McDaniel, Mark A.; Little, Jeri L.

2016-01-01

Despite the fundamental role of category learning in cognition, few studies have examined how this ability differs between younger and older adults. The present experiment examined possible age differences in category learning strategies and their effects on learning. Participants were trained on a category determined by a disjunctive rule applied to relational features. The utilization of rule- and exemplar-based strategies was indexed by self-reports and transfer performance. Based on self-reported strategies, both age groups had comparable frequencies of rule- and exemplar-based learners, but older adults had a higher frequency of intermediate learners (i.e., learners not identifying with a reliance on either rule- or exemplar-based strategies). Training performance was higher for younger than older adults regardless of the strategy utilized, showing that older adults were impaired in their ability to learn the correct rule or to remember exemplar-label associations. Transfer performance converged with strategy reports in showing higher fidelity category representations for younger adults. Younger adults with high working memory capacity were more likely to use an exemplar-based strategy, and older adults with high working memory capacity showed better training performance. Age groups did not differ in their self-reported memory beliefs, and these beliefs did not predict training strategies or performance. Overall, the present results contradict earlier findings that older adults prefer rule- to exemplar-based learning strategies, presumably to compensate for memory deficits. PMID:26950225

Coordinated prefrontal-hippocampal activity and navigation strategy-related prefrontal firing during spatial memory formation.

PubMed

Negrón-Oyarzo, Ignacio; Espinosa, Nelson; Aguilar, Marcelo; Fuenzalida, Marco; Aboitiz, Francisco; Fuentealba, Pablo

2018-06-18

Learning the location of relevant places in the environment is crucial for survival. Such capacity is supported by a distributed network comprising the prefrontal cortex and hippocampus, yet it is not fully understood how these structures cooperate during spatial reference memory formation. Hence, we examined neural activity in the prefrontal-hippocampal circuit in mice during acquisition of spatial reference memory. We found that interregional oscillatory coupling increased with learning, specifically in the slow-gamma frequency (20 to 40 Hz) band during spatial navigation. In addition, mice used both spatial and nonspatial strategies to navigate and solve the task, yet prefrontal neuronal spiking and oscillatory phase coupling were selectively enhanced in the spatial navigation strategy. Lastly, a representation of the behavioral goal emerged in prefrontal spiking patterns exclusively in the spatial navigation strategy. These results suggest that reference memory formation is supported by enhanced cortical connectivity and evolving prefrontal spiking representations of behavioral goals.

Increasing Memory Self-Efficacy and Strategy Use in Hispanic Elders

PubMed Central

McDougall, Graham J.

2008-01-01

This study tested the effects of a 4-week, nine-session group intervention taught in Spanish to Hispanic older adults entitled “Quieres Mejorar Tu Memoria” (Do you wish to improve your memory?). The program was based on Bandura’s self-efficacy theory and was designed to increase memory self-efficacy and strategy use. A total of 33 older adults attending a senior center (mean--age = 69 years; education = 5 years; MMSE = 25) participated in the study. A booster session and a post-test were given at 3 months to the intervention group (n=22). At posttest the intervention reported greater confidence in preventing decline in their memories, and in particular greater use of the internal strategy of elaboration (2.99 vs. 3.41), and the external strategies of list (2.55 vs. 3.38) and note (3.27 vs. 3.75). PMID:18802497

Semantic processes leading to true and false memory formation in schizophrenia.

PubMed

Paz-Alonso, Pedro M; Ghetti, Simona; Ramsay, Ian; Solomon, Marjorie; Yoon, Jong; Carter, Cameron S; Ragland, J Daniel

2013-07-01

Encoding semantic relationships between items on word lists (semantic processing) enhances true memories, but also increases memory distortions. Episodic memory impairments in schizophrenia (SZ) are strongly driven by failures to process semantic relations, but the exact nature of these relational semantic processing deficits is not well understood. Here, we used a false memory paradigm to investigate the impact of implicit and explicit semantic processing manipulations on episodic memory in SZ. Thirty SZ and 30 demographically matched healthy controls (HC) studied Deese/Roediger-McDermott (DRM) lists of semantically associated words. Half of the lists had strong implicit semantic associations and the remainder had low strength associations. Similarly, half of the lists were presented under "standard" instructions and the other half under explicit "relational processing" instructions. After study, participants performed recall and old/new recognition tests composed of targets, critical lures, and unrelated lures. HC exhibited higher true memories and better discriminability between true and false memory compared to SZ. High, versus low, associative strength increased false memory rates in both groups. However, explicit "relational processing" instructions positively improved true memory rates only in HC. Finally, true and false memory rates were associated with severity of disorganized and negative symptoms in SZ. These results suggest that reduced processing of semantic relationships during encoding in SZ may stem from an inability to implement explicit relational processing strategies rather than a fundamental deficit in the implicit activation and retrieval of word meanings from patients' semantic lexicon. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of Flood Control Strategies on Flood Resilience Under Sociohydrological Disturbances

NASA Astrophysics Data System (ADS)

Sung, Kyungmin; Jeong, Hanseok; Sangwan, Nikhil; Yu, David J.

2018-04-01

A community capacity to cope with flood hazards, or community flood resilience, emerges from the interplay of hydrological and social processes. This interplay can be significantly influenced by the flood control strategy adopted by a society, i.e., how a society sets its desired flood protection level and strives to achieve this goal. And this interplay can be further complicated by rising land-sea level differences, seasonal water level fluctuations, and economic change. But not much research has been done on how various forms of flood control strategies affect human-flood interactions under these disturbances and therefore flood resilience in the long run. The current study is an effort to address these issues by developing a conceptual model of human-flood interaction mediated by flood control strategies. Our model extends the existing model of Yu et al. (2017), who investigated the flood resilience of a community-based flood protection system in coastal Bangladesh. The major extensions made in this study are inclusions of various forms of flood control strategies (both adaptive and nonadaptive ones), the challenge of rising land-sea level differences, and various high tide level scenarios generated from modifying the statistical variances and averages. Our results show that adaptive forms of flood control strategies tend to outperform nonadaptive ones for maintaining the model community's flood protection system. Adaptive strategies that dynamically adjust target flood protection levels through close monitoring of flood damages and social memories of flood risk can help the model community deal with various disturbances.

Self-Regulatory Strategies in Daily Life: Selection, Optimization, and Compensation and Everyday Memory Problems

PubMed Central

Stephanie, Robinson; Margie, Lachman; Elizabeth, Rickenbach

2015-01-01

The effective use of self-regulatory strategies, such as selection, optimization, and compensation (SOC) requires resources. However, it is theorized that SOC use is most advantageous for those experiencing losses and diminishing resources. The present study explored this seeming paradox within the context of limitations or constraints due to aging, low cognitive resources, and daily stress in relation to everyday memory problems. We examined whether SOC usage varied by age and level of constraints, and if the relationship between resources and memory problems was mitigated by SOC usage. A daily diary paradigm was used to explore day-to-day fluctuations in these relationships. Participants (n=145, ages 22 to 94) completed a baseline interview and a daily diary for seven consecutive days. Multilevel models examined between- and within-person relationships between daily SOC use, daily stressors, cognitive resources, and everyday memory problems. Middle-aged adults had the highest SOC usage, although older adults also showed high SOC use if they had high cognitive resources. More SOC strategies were used on high stress compared to low stress days. Moreover, the relationship between daily stress and memory problems was buffered by daily SOC use, such that on high-stress days, those who used more SOC strategies reported fewer memory problems than participants who used fewer SOC strategies. The paradox of resources and SOC use can be qualified by the type of resource-limitation. Deficits in global resources were not tied to SOC usage or benefits. Conversely, under daily constraints tied to stress, the use of SOC increased and led to fewer memory problems. PMID:26997686

Cognitive Function in a Randomized Trial of Evolocumab.

PubMed

Giugliano, Robert P; Mach, François; Zavitz, Kenton; Kurtz, Christopher; Im, Kyungah; Kanevsky, Estella; Schneider, Jingjing; Wang, Huei; Keech, Anthony; Pedersen, Terje R; Sabatine, Marc S; Sever, Peter S; Robinson, Jennifer G; Honarpour, Narimon; Wasserman, Scott M; Ott, Brian R

2017-08-17

Background Findings from clinical trials of proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors have led to concern that these drugs or the low levels of low-density lipoprotein (LDL) cholesterol that result from their use are associated with cognitive deficits. Methods In a subgroup of patients from a randomized, placebo-controlled trial of evolocumab added to statin therapy, we prospectively assessed cognitive function using the Cambridge Neuropsychological Test Automated Battery. The primary end point was the score on the spatial working memory strategy index of executive function (scores range from 4 to 28, with lower scores indicating a more efficient use of strategy and planning). Secondary end points were the scores for working memory (scores range from 0 to 279, with lower scores indicating fewer errors), episodic memory (scores range from 0 to 70, with lower scores indicating fewer errors), and psychomotor speed (scores range from 100 to 5100 msec, with faster times representing better performance). Assessments of cognitive function were performed at baseline, week 24, yearly, and at the end of the trial. The primary analysis was a noninferiority comparison of the mean change from baseline in the score on the spatial working memory strategy index of executive function between the patients who received evolocumab and those who received placebo; the noninferiority margin was set at 20% of the standard deviation of the score in the placebo group. Results A total of 1204 patients were followed for a median of 19 months; the mean (±SD) change from baseline over time in the raw score for the spatial working memory strategy index of executive function (primary end point) was -0.21±2.62 in the evolocumab group and -0.29±2.81 in the placebo group (P<0.001 for noninferiority; P=0.85 for superiority). There were no significant between-group differences in the secondary end points of scores for working memory (change in raw score, -0.52 in the evolocumab group and -0.93 in the placebo group), episodic memory (change in raw score, -1.53 and -1.53, respectively), or psychomotor speed (change in raw score, 5.2 msec and 0.9 msec, respectively). In an exploratory analysis, there were no associations between LDL cholesterol levels and cognitive changes. Conclusions In a randomized trial involving patients who received either evolocumab or placebo in addition to statin therapy, no significant between-group difference in cognitive function was observed over a median of 19 months. (Funded by Amgen; EBBINGHAUS ClinicalTrials.gov number, NCT02207634 .).

Genetic Dissection of Learning and Memory in Mice

PubMed Central

Mineur, Yann S.; Crusio, Wim E.; Sluyter, Frans

2004-01-01

In this minireview, we discuss different strategies to dissect genetically the keystones of learning and memory. First, we broadly sketch the neurogenetic analysis of complex traits in mice. We then discuss two general strategies to find genes affecting learning and memory: candidate gene studies and whole genome searches. Next, we briefly review more recently developed techniques, such as microarrays and RNA interference. In addition, we focus on gene-environment interactions and endophenotypes. All sections are illustrated with examples from the learning and memory field, including a table summarizing the latest information about genes that have been shown to have effects on learning and memory. PMID:15656270

A Feedback Control Model of Comprehensive Therapy for Treating Immunogenic Tumours

NASA Astrophysics Data System (ADS)

Tang, Biao; Xiao, Yanni; Tang, Sanyi; Cheke, Robert A.

Surgery is the traditional method for treating cancers, but it often fails to cure patients for complex reasons so new therapeutic approaches that include both surgery and immunotherapy have recently been proposed. These have been shown to be effective, clinically, in inhibiting cancer cells while allowing retention of immunologic memory. This comprehensive strategy is guided by whether a population of tumour cells has or has not exceeded a threshold density. Conditions for successful control of tumours in an immune tumour system were modeled and the related dynamics were addressed. A mathematical model with state-dependent impulsive interventions is formulated to describe combinations of surgery with immunotherapy. By analyzing the properties of the Poincaré map, we examine the global dynamics of the immune tumour system with state-dependent feedback control, including the existence and stability of the semi-trivial order-1 periodic solution and the positive order-k periodic solution. The main results showed that surgery alone can only control the tumour size below a certain level while there is no immunologic memory. If comprehensive therapy involving combining surgery with immunotherapy is considered, then not only can the cancers be controlled below a certain level, but the immune system can also retain its activity. The existence of positive order-k periodic solutions implies that periodical therapy is needed to control the cancers. However, choosing the treatment frequency and the strength of the therapy remains challenging, and hence a strategy of individual-based therapy is suggested.

[Cognitive aging mechanism of signaling effects on the memory for procedural sentences].

PubMed

Yamamoto, Hiroki; Shimada, Hideaki

2006-08-01

The aim of this study was to clarify the cognitive aging mechanism of signaling effects on the memory for procedural sentences. Participants were 60 younger adults (college students) and 60 older adults. Both age groups were assigned into two groups; half of each group was presented with procedural sentences with signals that highlighted their top-level structure and the other half with procedural sentences without them. Both groups were requested to perform the sentence arrangement task and the reconstruction task. Each task was composed of procedural sentences with or without signals. Results indicated that signaling supported changes in strategy utilization during the successive organizational processes and that changes in strategy utilization resulting from signaling improved the memory for procedural sentences. Moreover, age-related factors interfered with these signaling effects. This study clarified the cognitive aging mechanism of signaling effects in which signaling supports changes in the strategy utilization during organizational processes at encoding and this mediation promotes memory for procedural sentences, though disuse of the strategy utilization due to aging restrains their memory for procedural sentences.

MPEG-1 low-cost encoder solution

NASA Astrophysics Data System (ADS)

Grueger, Klaus; Schirrmeister, Frank; Filor, Lutz; von Reventlow, Christian; Schneider, Ulrich; Mueller, Gerriet; Sefzik, Nicolai; Fiedrich, Sven

1995-02-01

A solution for real-time compression of digital YCRCB video data to an MPEG-1 video data stream has been developed. As an additional option, motion JPEG and video telephone streams (H.261) can be generated. For MPEG-1, up to two bidirectional predicted images are supported. The required computational power for motion estimation and DCT/IDCT, memory size and memory bandwidth have been the main challenges. The design uses fast-page-mode memory accesses and requires only one single 80 ns EDO-DRAM with 256 X 16 organization for video encoding. This can be achieved only by using adequate access and coding strategies. The architecture consists of an input processing and filter unit, a memory interface, a motion estimation unit, a motion compensation unit, a DCT unit, a quantization control, a VLC unit and a bus interface. For using the available memory bandwidth by the processing tasks, a fixed schedule for memory accesses has been applied, that can be interrupted for asynchronous events. The motion estimation unit implements a highly sophisticated hierarchical search strategy based on block matching. The DCT unit uses a separated fast-DCT flowgraph realized by a switchable hardware unit for both DCT and IDCT operation. By appropriate multiplexing, only one multiplier is required for: DCT, quantization, inverse quantization, and IDCT. The VLC unit generates the video-stream up to the video sequence layer and is directly coupled with an intelligent bus-interface. Thus, the assembly of video, audio and system data can easily be performed by the host computer. Having a relatively low complexity and only small requirements for DRAM circuits, the developed solution can be applied to low-cost encoding products for consumer electronics.

Cognitive costs of decision-making strategies: A resource demand decomposition analysis with a cognitive architecture.

PubMed

Fechner, Hanna B; Schooler, Lael J; Pachur, Thorsten

2018-01-01

Several theories of cognition distinguish between strategies that differ in the mental effort that their use requires. But how can the effort-or cognitive costs-associated with a strategy be conceptualized and measured? We propose an approach that decomposes the effort a strategy requires into the time costs associated with the demands for using specific cognitive resources. We refer to this approach as resource demand decomposition analysis (RDDA) and instantiate it in the cognitive architecture Adaptive Control of Thought-Rational (ACT-R). ACT-R provides the means to develop computer simulations of the strategies. These simulations take into account how strategies interact with quantitative implementations of cognitive resources and incorporate the possibility of parallel processing. Using this approach, we quantified, decomposed, and compared the time costs of two prominent strategies for decision making, take-the-best and tallying. Because take-the-best often ignores information and foregoes information integration, it has been considered simpler than strategies like tallying. However, in both ACT-R simulations and an empirical study we found that under increasing cognitive demands the response times (i.e., time costs) of take-the-best sometimes exceeded those of tallying. The RDDA suggested that this pattern is driven by greater requirements for working memory updates, memory retrievals, and the coordination of mental actions when using take-the-best compared to tallying. The results illustrate that assessing the relative simplicity of strategies requires consideration of the overall cognitive system in which the strategies are embedded. Copyright © 2017 Elsevier B.V. All rights reserved.

The sensitivity of a virtual reality task to planning and prospective memory impairments: group differences and the efficacy of periodic alerts on performance.

PubMed

Sweeney, Siobhan; Kersel, Denyse; Morris, Robin G; Manly, Tom; Evans, Jonathan J

2010-04-01

Executive functions have been argued to be the most vulnerable to brain injury. In providing an analogue of everyday situations amenable to control and management virtual reality (VR) may offer better insights into planning deficits consequent upon brain injury. Here 17 participants with a non-progressive brain injury and reported executive difficulties in everyday life were asked to perform a VR task (working in a furniture storage unit) that emphasised planning, rule following and prospective memory tasks. When compared with an age and IQ-matched control group, the patients were significantly poorer in terms of their strategy, their time-based prospective memory, the overall time required and their propensity to break rules. An examination of sensitivity and specificity of the VR task to group membership (brain-injured or control) showed that, with specificity set at maximum, sensitivity was only modest (at just over 50%). A second component to the study investigated whether the patients' performance could be improved by periodic auditory alerts. Previous studies have demonstrated that such cues can improve performance on laboratory tests, executive tests and everyday prospective memory tasks. Here, no significant changes in performance were detected. Potential reasons for this finding are discussed, including symptom severity and differences in the tasks employed in previous studies.

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

Memory and Cognitive Strategies of High Ability Students in a Rural Secondary School

ERIC Educational Resources Information Center

Ali, Fuziana; Yunus, Melor Md

2013-01-01

This study was conducted to examine language learning strategies employed by the high ability students in a rural secondary school. Memory and cognitive strategies employed by the high ability students were the main focus in this study. A survey design was used and data was collected using Oxford's questionnaires. Findings reveal that the high…

The Impact of Strategy Instruction and Timing of Estimates on Low and High Working-Memory Capacity Readers' Absolute Monitoring Accuracy

ERIC Educational Resources Information Center

Linderholm, Tracy; Zhao, Qin

2008-01-01

Working-memory capacity, strategy instruction, and timing of estimates were investigated for their effects on absolute monitoring accuracy, which is the difference between estimated and actual reading comprehension test performance. Participants read two expository texts under one of two randomly assigned reading strategy instruction conditions…

Increased numbers of pre-existing memory CD8 T cells and decreased T-bet expression can restrain terminal differentiation of secondary effector and memory CD8 T cells1

PubMed Central

Joshi, Nikhil S.; Cui, Weiguo; Dominguez, Claudia; Chen, Jonathan H.; Hand, Timothy W.; Kaech, Susan M.

2011-01-01

Memory CD8 T cells acquire TEM properties following reinfection, and may reach terminally differentiated, senescent states (“Hayflick limit”) after multiple infections. The signals controlling this process are not well understood, but we found that the degree of 2o effector and memory CD8 T cell differentiation was intimately linked to the amount of T-bet expressed upon reactivation and pre-existing memory CD8 T cell number (i.e., 1o memory CD8 T cell precursor frequency) present during secondary infection. Compared to naïve cells, memory CD8 T cells were predisposed towards terminal effector (TE) cell differentiation because they could immediately respond to IL-12 and induce T-bet, even in the absence of antigen. TE cell formation following 2o or 3o infections was dependent on increased T-bet expression because T-bet+/− cells were resistant to these phenotypic changes. Larger numbers of pre-existing memory CD8 T cells limited the duration of 2o infection and the amount of IL-12 produced, and consequently, this reduced T-bet expression and the proportion of 2o TE CD8 T cells that formed. Together, these data show that, over repeated infections, memory CD8 T cell quality and proliferative fitness is not strictly determined by the number of serial encounters with antigen or cell divisions, but is a function of the CD8 T cell differentiation state, which is genetically controlled in a T-bet-dependent manner. This differentiation state can be modulated by pre-existing memory CD8 T cell number and the intensity of inflammation during reinfection. These results have important implications for vaccinations involving prime-boost strategies. PMID:21930973

Natural selection of memory-one strategies for the iterated prisoner's dilemma.

PubMed

Kraines, D P; Kraines, V Y

2000-04-21

In the iterated Prisoner's Dilemma, mutually cooperative behavior can become established through Darwinian natural selection. In simulated interactions of stochastic memory-one strategies for the Iterated Prisoner's Dilemma, Nowak and Sigmund discovered that cooperative agents using a Pavlov (Win-Stay Lose-Switch) type strategy eventually dominate a random population. This emergence follows more directly from a deterministic dynamical system based on differential reproductive success or natural selection. When restricted to an environment of memory-one agents interacting in iterated Prisoner's Dilemma games with a 1% noise level, the Pavlov agent is the only cooperative strategy and one of very few others that cannot be invaded by a similar strategy. Pavlov agents are trusting but no suckers. They will exploit weakness but repent if punished for cheating. Copyright 2000 Academic Press.

Solid State Spin-Wave Quantum Memory for Time-Bin Qubits.

PubMed

Gündoğan, Mustafa; Ledingham, Patrick M; Kutluer, Kutlu; Mazzera, Margherita; de Riedmatten, Hugues

2015-06-12

We demonstrate the first solid-state spin-wave optical quantum memory with on-demand read-out. Using the full atomic frequency comb scheme in a Pr(3+):Y2SiO5 crystal, we store weak coherent pulses at the single-photon level with a signal-to-noise ratio >10. Narrow-band spectral filtering based on spectral hole burning in a second Pr(3+):Y2SiO5 crystal is used to filter out the excess noise created by control pulses to reach an unconditional noise level of (2.0±0.3)×10(-3) photons per pulse. We also report spin-wave storage of photonic time-bin qubits with conditional fidelities higher than achievable by a measure and prepare strategy, demonstrating that the spin-wave memory operates in the quantum regime. This makes our device the first demonstration of a quantum memory for time-bin qubits, with on-demand read-out of the stored quantum information. These results represent an important step for the use of solid-state quantum memories in scalable quantum networks.

Memory Enhancement by Targeting Cdk5 Regulation of NR2B

PubMed Central

Plattner, Florian; Hernandéz, Adan; Kistler, Tara M.; Pozo, Karine; Zhong, Ping; Yuen, Eunice Y.; Tan, Chunfeng; Hawasli, Ammar H.; Cooke, Sam F.; Nishi, Akinori; Guo, Ailan; Wiederhold, Thorsten; Yan, Zhen; Bibb, James A.

2014-01-01

SUMMARY Many psychiatric and neurological disorders are characterized by learning and memory deficits, for which cognitive enhancement is considered a valid treatment strategy. The N-methyl-D-aspartate receptor (NMDAR) is a prime target for the development of cognitive enhancers due to its fundamental role in learning and memory. In particular, the NMDAR subunit NR2B improves synaptic plasticity and memory when over-expressed in neurons. However, NR2B regulation is not well understood and no therapies potentiating NMDAR function have been developed. Here, we show that serine 1116 of NR2B is phosphorylated by cyclin-dependent kinase 5 (Cdk5). Cdk5-dependent NR2B phosphorylation is regulated by neuronal activity and controls the receptor’s cell surface expression. Disrupting NR2B-Cdk5 interaction using a small interfering peptide (siP) increases NR2B surface levels, facilitates synaptic transmission, and improves memory formation in vivo. Our results reveal a novel regulatory mechanism critical to NR2B function that can be targeted for the development of cognitive enhancers. PMID:24607229

VOP memory management in MPEG-4

NASA Astrophysics Data System (ADS)

Vaithianathan, Karthikeyan; Panchanathan, Sethuraman

2001-03-01

MPEG-4 is a multimedia standard that requires Video Object Planes (VOPs). Generation of VOPs for any kind of video sequence is still a challenging problem that largely remains unsolved. Nevertheless, if this problem is treated by imposing certain constraints, solutions for specific application domains can be found. MPEG-4 applications in mobile devices is one such domain where the opposite goals namely low power and high throughput are required to be met. Efficient memory management plays a major role in reducing the power consumption. Specifically, efficient memory management for VOPs is difficult because the lifetimes of these objects vary and these life times may be overlapping. Varying life times of the objects requires dynamic memory management where memory fragmentation is a key problem that needs to be addressed. In general, memory management systems address this problem by following a combination of strategy, policy and mechanism. For MPEG4 based mobile devices that lack instruction processors, a hardware based memory management solution is necessary. In MPEG4 based mobile devices that have a RISC processor, using a Real time operating system (RTOS) for this memory management task is not expected to be efficient because the strategies and policies used by the ROTS is often tuned for handling memory segments of smaller sizes compared to object sizes. Hence, a memory management scheme specifically tuned for VOPs is important. In this paper, different strategies, policies and mechanisms for memory management are considered and an efficient combination is proposed for the case of VOP memory management along with a hardware architecture, which can handle the proposed combination.

Prospective memory, everyday cognitive failure and central executive function in recreational users of Ecstasy.

PubMed

Heffernan, T. M.; Jarvis, H.; Rodgers, J.; Scholey, A. B.; Ling, J.

2001-12-01

Chronic use of MDMA (3,4-methylenedioxymethamphetamine), or Ecstasy, is believed to lead to impaired psychological performance, including well-documented decrements in laboratory and field tests of retrospective memory. Less is known about the impact of Ecstasy on aspects of 'everyday' memory, despite obvious concerns about such effects. The three studies reported here focused on the impact of chronic Ecstasy use on prospective memory (PM), associated central executive function and other aspects of day-to-day cognition. In study 1 46 regular Ecstasy users were compared with 46 Ecstasy-free controls using the Prospective Memory Questionnaire (PMQ). Ecstasy users reported significantly more errors in PM (remembering to do something in the future); these findings persisted after controlling for other drug use and the number of strategies used to aid memory. No difference was found between representative subgroups on the Lies Scale of the Eysenck Personality Questionnaire. In study 2 a different group of 30 regular Ecstasy users and 37 Ecstasy-free controls was assessed on the PMQ and on a central executive task comprising verbal fluency measures. The results confirmed the significant impairments in long- and short-term PM and revealed corresponding impairments in verbal fluency. In study 3 15 Ecstasy users, 15 cannabis users and 15 non-drug users were assessed using the Cognitive Failures Questionnaire, which requires participants to provide ratings of the frequency of various day-to-day cognitive slips. The results indicate that the Ecstasy users did not perceive their general cognitive performance to be worse than that of controls. Taken together, these results suggest that Ecstasy users have impaired PM that cannot be explained by an increased propensity to exaggerate cognitive failures. These may be attributable, in part, to central executive deficits that are due to frontal lobe damage associated with Ecstasy use. Copyright 2001 John Wiley & Sons, Ltd.

Levels-of-processing effects in first-degree relatives of individuals with schizophrenia.

PubMed

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

2007-05-15

First-degree relatives of individuals with schizophrenia show cognitive impairments that are similar to but less severe than their ill relatives. We have shown that memory impairments can be improved and prefrontal cortical (PFC) activity increased in individuals with schizophrenia by providing beneficial encoding strategies. The current study used a similar paradigm to determine whether siblings of individuals with schizophrenia (SIBs) also show increases in brain activity when presented with beneficial encoding strategies. Twenty-one SIBs and 38 siblings of healthy comparison subjects underwent functional magnetic resonance imaging scans while engaged in deep (abstract/concrete judgments) and shallow (orthographic judgments) encoding. Subjects were then given a recognition memory test. The groups did not differ on encoding or recognition accuracy, and the SIBs benefited from deep encoding to a similar degree as control subjects. The SIBs showed deep encoding-related activity in a number of PFC regions typically activated during semantic processing. However, SIBs showed more activity than control subjects in three subregions of PFC (left BA 44 & BA 47 bilaterally). Siblings of individuals with schizophrenia benefit from supportive verbal encoding conditions. Like individuals with schizophrenia, SIBs also show increased task-related activity in a larger number of PFC subregions than control subjects during deep verbal encoding.

Screening for Alzheimer's Disease: Cognitive Impairment in Self-Referred and Memory Clinic-Referred Patients.

PubMed

Kirsebom, Bjørn-Eivind; Espenes, Ragna; Waterloo, Knut; Hessen, Erik; Johnsen, Stein Harald; Bråthen, Geir; Aarsland, Dag; Fladby, Tormod

2017-01-01

Cognitive assessment is essential in tracking disease progression in AD. Presently, cohorts including preclinical at-risk participants are recruited by different means, which may bias cognitive and clinical features. We compared recruitment strategies to levels of cognitive functioning. We investigate recruitment source biases in self-referred and memory clinic-referred patient cohorts to reveal potential differences in cognitive performance and demographics among at-risk participants. We included 431 participants 40-80 years old. Participants were classified as controls (n = 132) or symptom group (n = 299). The symptom group comprised of subjective cognitive decline (SCD, n = 163) and mild cognitive impairment (MCI, n = 136). We compared cognitive performance and demographics in memory clinic-referrals (n = 86) to self-referred participants responding to advertisements and news bulletins (n = 179). Participants recruited by other means were excluded from analysis (n = 34). At symptom group level, we found significant reductions in cognitive performance in memory clinic-referrals compared to self-referrals. However, here reductions were only found within the MCI group. We found no differences in cognitive performance due to recruitment within the SCD group. The MCI group was significantly impaired compared to controls on all measures. Significant reductions in learning, and executive functions were also found for the SCD group. Regardless of recruitment method, both the SCD and MCI groups showed reductions in cognitive performance compared to controls. We found differences in cognitive impairment for memory clinic-referrals compared to self-referrals only within the MCI group, SCD-cases being equally affected irrespective of referral type.

Molecular implementation of molecular shift register memories

NASA Technical Reports Server (NTRS)

Beratan, David N. (Inventor); Onuchic, Jose N. (Inventor)

1991-01-01

An electronic shift register memory (20) at the molecular level is described. The memory elements are based on a chain of electron transfer molecules (22) and the information is shifted by photoinduced (26) electron transfer reactions. Thus, multi-step sequences of charge transfer reactions are used to move charge with high efficiency down a molecular chain. The device integrates compositions of the invention onto a VLSI substrate (36), providing an example of a molecular electronic device which may be fabricated. Three energy level schemes, molecular implementation of these schemes, optical excitation strategies, charge amplification strategies, and error correction strategies are described.

Brain substrates of implicit and explicit memory: the importance of concurrently acquired neural signals of both memory types.

PubMed

Voss, Joel L; Paller, Ken A

2008-11-01

A comprehensive understanding of human memory requires cognitive and neural descriptions of memory processes along with a conception of how memory processing drives behavioral responses and subjective experiences. One serious challenge to this endeavor is that an individual memory process is typically operative within a mix of other contemporaneous memory processes. This challenge is particularly disquieting in the context of implicit memory, which, unlike explicit memory, transpires without the subject necessarily being aware of memory retrieval. Neural correlates of implicit memory and neural correlates of explicit memory are often investigated in different experiments using very different memory tests and procedures. This strategy poses difficulties for elucidating the interactions between the two types of memory process that may result in explicit remembering, and for determining the extent to which certain neural processing events uniquely contribute to only one type of memory. We review recent studies that have succeeded in separately assessing neural correlates of both implicit memory and explicit memory within the same paradigm using event-related brain potentials (ERPs) and functional magnetic resonance imaging (fMRI), with an emphasis on studies from our laboratory. The strategies we describe provide a methodological framework for achieving valid assessments of memory processing, and the findings support an emerging conceptualization of the distinct neurocognitive events responsible for implicit and explicit memory.

Topographical memory for newly-learned maps is differentially affected by route-based versus landmark-based learning: a functional MRI study.

PubMed

Beatty, Erin L; Muller-Gass, Alexandra; Wojtarowicz, Dorothy; Jobidon, Marie-Eve; Smith, Ingrid; Lam, Quan; Vartanian, Oshin

2018-04-11

Humans rely on topographical memory to encode information about spatial aspects of environments. However, even though people adopt different strategies when learning new maps, little is known about the impact of those strategies on topographical memory, and their neural correlates. To examine that issue, we presented participants with 40 unfamiliar maps, each of which displayed one major route and three landmarks. Half were instructed to memorize the maps by focusing on the route, whereas the other half memorized the maps by focusing on the landmarks. One day later, the participants were tested on their ability to distinguish previously studied 'old' maps from completely unfamiliar 'new' maps under conditions of high and low working memory load in the functional MRI scanner. Viewing old versus new maps was associated with relatively greater activation in a distributed set of regions including bilateral inferior temporal gyrus - an important region for recognizing visual objects. Critically, whereas the performance of participants who had followed a route-based strategy dropped to chance level under high working memory load, participants who had followed a landmark-based strategy performed at above chance levels under both high and low working memory load - reflected by relatively greater activation in the left inferior parietal lobule (i.e. rostral part of the supramarginal gyrus known as area PFt). Our findings suggest that landmark-based learning may buffer against the effects of working memory load during recognition, and that this effect is represented by the greater involvement of a brain region implicated in both topographical and working memory.

Using maintenance rehearsal to explore recognition memory.

PubMed

Humphreys, Michael S; Maguire, Angela M; McFarlane, Kimberley A; Burt, Jennifer S; Bolland, Scott W; Murray, Krista L; Dunn, Ryan

2010-01-01

We examined associative and item recognition using the maintenance rehearsal paradigm. Our intent was to control for mnemonic strategies; to produce a low, graded level of learning; and to provide evidence of the role of attention in long-term memory. An advantage for low-frequency words emerged in both associative and item recognition at very low levels of learning. This early emergence casts doubt on explanations based on the traditional concept of recollection. A comparison of false alarms supports a role for item information or the joint use of cues but not familiarity in producing associative false alarms. We may also have found a way to measure the amount of attention being paid to a to-be-learned item or pair, independently of memory performance on the attended item. This result may be an important step in determining whether coherent theories about the role of attention in long- and short-term memory can be created. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

The Development and Use of Memory Strategies by Deaf Children and Adults.

ERIC Educational Resources Information Center

Liben, Lynn S.

The availability and application of particular memory strategies by deaf children and adults was examined. In the first study, 20 younger (mean age, 6 years, 3 months) and 20 older (8 years, 8 months) children's use of rehearsal strategies was examined with a serial probe task. All four types of stimuli (animals, nonsense shapes, hands, print)…

The Influence of Personality Traits on the Use of Memory English Language Learning Strategies

ERIC Educational Resources Information Center

Fazeli, Seyed Hossein

2012-01-01

The present study aims to find out the influence of personality traits on the choice and use of Memory English Language Learning Strategies (MELLSs) for learners of English as a foreign language, and the role of personality traits in the prediction of use of such Strategies. Four instruments were used, which were Adapted Inventory for Memory…

Children's use of decomposition strategies mediates the visuospatial memory and arithmetic accuracy relation.

PubMed

Foley, Alana E; Vasilyeva, Marina; Laski, Elida V

2017-06-01

This study examined the mediating role of children's use of decomposition strategies in the relation between visuospatial memory (VSM) and arithmetic accuracy. Children (N = 78; Age M = 9.36) completed assessments of VSM, arithmetic strategies, and arithmetic accuracy. Consistent with previous findings, VSM predicted arithmetic accuracy in children. Extending previous findings, the current study showed that the relation between VSM and arithmetic performance was mediated by the frequency of children's use of decomposition strategies. Identifying the role of arithmetic strategies in this relation has implications for increasing the math performance of children with lower VSM. Statement of contribution What is already known on this subject? The link between children's visuospatial working memory and arithmetic accuracy is well documented. Frequency of decomposition strategy use is positively related to children's arithmetic accuracy. Children's spatial skill positively predicts the frequency with which they use decomposition. What does this study add? Short-term visuospatial memory (VSM) positively relates to the frequency of children's decomposition use. Decomposition use mediates the relation between short-term VSM and arithmetic accuracy. Children with limited short-term VSM may struggle to use decomposition, decreasing accuracy. © 2016 The British Psychological Society.

Application of the dual-component model of working memory to ADHD:Greater secondary memory deficit despite confounded cognitive differences.

PubMed

Gibson, Bradley S; Gondoli, Dawn M; Ralph, Kathryn J; Sztybel, Pedro

2018-01-01

The dual-component model postulates that working memory capacity consists of two dissociable components: maintenance in primary memory (PM) and retrieval from secondary memory (SM). Recent application of this model to attention-deficit/hyperactivity disorder (ADHD) has revealed that the SM component is more deficient than the PM component across both verbal and spatial modalities. The present study attempts to strengthen this conclusion by addressing two weaknesses in the previous study. First, the present study shows that the SM component continues to be more deficient than the PM component across both modalities under conditions in which (1) all participants were instructed to use the same recall strategy (resulting in the exclusion of fewer participants); and, (2) individual differences in this strategy were controlled. Second, the present study also documents a group difference in word reading efficiency that is confounded with diagnostic status and that might have influenced estimates of PM and SM capacities in the verbal modality. However, although the SM component is more deficient than the PM component in the ADHD group, the magnitude of this interaction does not vary as a function task modality. These findings are interpreted to suggest that the pattern of WM deficiencies observed are part of a causal pathway that can lead to the symptoms of ADHD, as well as to impairments in reading (and intelligence) due to overlapping cue-dependent retrieval mechanisms. These findings provide additional support for the notion that the SM component of WM is an important and neglected target for treatment.

Dissociation of spatial memory systems in Williams syndrome.

PubMed

Bostelmann, Mathilde; Fragnière, Emilie; Costanzo, Floriana; Di Vara, Silvia; Menghini, Deny; Vicari, Stefano; Lavenex, Pierre; Lavenex, Pamela Banta

2017-11-01

Williams syndrome (WS), a genetic deletion syndrome, is characterized by severe visuospatial deficits affecting performance on both tabletop spatial tasks and on tasks which assess orientation and navigation. Nevertheless, previous studies of WS spatial capacities have ignored the fact that two different spatial memory systems are believed to contribute parallel spatial representations supporting navigation. The place learning system depends on the hippocampal formation and creates flexible relational representations of the environment, also known as cognitive maps. The spatial response learning system depends on the striatum and creates fixed stimulus-response representations, also known as habits. Indeed, no study assessing WS spatial competence has used tasks which selectively target these two spatial memory systems. Here, we report that individuals with WS exhibit a dissociation in their spatial abilities subserved by these two memory systems. As compared to typically developing (TD) children in the same mental age range, place learning performance was impaired in individuals with WS. In contrast, their spatial response learning performance was facilitated. Our findings in individuals with WS and TD children suggest that place learning and response learning interact competitively to control the behavioral strategies normally used to support human spatial navigation. Our findings further suggest that the neural pathways supporting place learning may be affected by the genetic deletion that characterizes WS, whereas those supporting response learning may be relatively preserved. The dissociation observed between these two spatial memory systems provides a coherent theoretical framework to characterize the spatial abilities of individuals with WS, and may lead to the development of new learning strategies based on their facilitated response learning abilities. © 2017 Wiley Periodicals, Inc.

Reasoning and dyslexia: is visual memory a compensatory resource?

PubMed

Bacon, Alison M; Handley, Simon J

2014-11-01

Effective reasoning is fundamental to problem solving and achievement in education and employment. Protocol studies have previously suggested that people with dyslexia use reasoning strategies based on visual mental representations, whereas non-dyslexics use abstract verbal strategies. This research presents converging evidence from experimental and individual differences perspectives. In Experiment 1, dyslexic and non-dyslexic participants were similarly accurate on reasoning problems, but scores on a measure of visual memory ability only predicted reasoning accuracy for dyslexics. In Experiment 2, a secondary task loaded visual memory resources during concurrent reasoning. Dyslexics were significantly less accurate when reasoning under conditions of high memory load and showed reduced ability to subsequently recall the visual stimuli, suggesting that the memory and reasoning tasks were competing for the same visual cognitive resource. The results are consistent with an explanation based on limitations in the verbal and executive components of working memory in dyslexia and the use of compensatory visual strategies for reasoning. There are implications for cognitive activities that do not readily support visual thinking, whether in education, employment or less formal everyday settings. Copyright © 2014 John Wiley & Sons, Ltd.

Preferential selection based on strategy persistence and memory promotes cooperation in evolutionary prisoner's dilemma games

NASA Astrophysics Data System (ADS)

Liu, Yuanming; Huang, Changwei; Dai, Qionglin

2018-06-01

Strategy imitation plays a crucial role in evolutionary dynamics when we investigate the spontaneous emergence of cooperation under the framework of evolutionary game theory. Generally, when an individual updates his strategy, he needs to choose a role model whom he will learn from. In previous studies, individuals choose role models randomly from their neighbors. In recent works, researchers have considered that individuals choose role models according to neighbors' attractiveness characterized by the present network topology or historical payoffs. Here, we associate an individual's attractiveness with the strategy persistence, which characterizes how frequently he changes his strategy. We introduce a preferential parameter α to describe the nonlinear correlation between the selection probability and the strategy persistence and the memory length of individuals M into the evolutionary games. We investigate the effects of α and M on cooperation. Our results show that cooperation could be promoted when α > 0 and at the same time M > 1, which corresponds to the situation that individuals are inclined to select their neighbors with relatively higher persistence levels during the evolution. Moreover, we find that the cooperation level could reach the maximum at an optimal memory length when α > 0. Our work sheds light on how to promote cooperation through preferential selection based on strategy persistence and a limited memory length.

Task-Selective Memory Effects for Successfully Implemented Encoding Strategies

PubMed Central

Leshikar, Eric D.; Duarte, Audrey; Hertzog, Christopher

2012-01-01

Previous behavioral evidence suggests that instructed strategy use benefits associative memory formation in paired associate tasks. Two such effective encoding strategies–visual imagery and sentence generation–facilitate memory through the production of different types of mediators (e.g., mental images and sentences). Neuroimaging evidence suggests that regions of the brain support memory reflecting the mental operations engaged at the time of study. That work, however, has not taken into account self-reported encoding task success (i.e., whether participants successfully generated a mediator). It is unknown, therefore, whether task-selective memory effects specific to each strategy might be found when encoding strategies are successfully implemented. In this experiment, participants studied pairs of abstract nouns under either visual imagery or sentence generation encoding instructions. At the time of study, participants reported their success at generating a mediator. Outside of the scanner, participants further reported the quality of the generated mediator (e.g., images, sentences) for each word pair. We observed task-selective memory effects for visual imagery in the left middle occipital gyrus, the left precuneus, and the lingual gyrus. No such task-selective effects were observed for sentence generation. Intriguingly, activity at the time of study in the left precuneus was modulated by the self-reported quality (vividness) of the generated mental images with greater activity for trials given higher ratings of quality. These data suggest that regions of the brain support memory in accord with the encoding operations engaged at the time of study. PMID:22693593

Understanding individual differences in representational abstraction: The role of working memory capacity.

PubMed

Stukken, Loes; Van Rensbergen, Bram; Vanpaemel, Wolf; Storms, Gert

2016-10-01

Several studies have reported differences in categorization strategies among participants: some learn a category by making abstraction across the category members while others use a memorization strategy. Despite the prevalence of these differences, little attention has been paid to investigating what influences some to use an abstraction strategy and others a memorization strategy. The current study had two goals: in a first experiment we investigated whether these differences were stable across time, using the parallel form method often used in psychometric research, and in a second experiment we investigated whether the individual differences in categorization strategy were related to working memory capacity. We used a modelling strategy, in which we not only focused on full abstraction and memorization strategies, but also on intermediate strategies in which some category members are abstracted and others are not. The first study revealed that the individual abstraction strategy of individual participants in two different experiments, performed at different times, correlate significantly, and second study showed that these individual differences were related to the working memory capacity of the participants. Copyright © 2016 Elsevier B.V. All rights reserved.

The role of metacognition in prospective memory: anticipated task demands influence attention allocation strategies.

PubMed

Rummel, Jan; Meiser, Thorsten

2013-09-01

The present study investigates how individuals distribute their attentional resources between a prospective memory task and an ongoing task. Therefore, metacognitive expectations about the attentional demands of the prospective-memory task were manipulated while the factual demands were held constant. In Experiments 1a and 1b, we found attentional costs from a prospective-memory task with low factual demands to be significantly reduced when information about the low to-be-expected demands were provided, while prospective-memory performance remained largely unaffected. In Experiment 2, attentional monitoring in a more demanding prospective-memory task also varied with information about the to-be-expected demands (high vs. low) and again there were no equivalent changes in prospective-memory performance. These findings suggest that attention-allocation strategies of prospective memory rely on metacognitive expectations about prospective-memory task demands. Furthermore, the results suggest that attentional monitoring is only functional for prospective memory to the extent to which anticipated task demands reflect objective task demands. Copyright © 2013 Elsevier Inc. All rights reserved.

Mental Imagery and Visual Working Memory

PubMed Central

Keogh, Rebecca; Pearson, Joel

2011-01-01

Visual working memory provides an essential link between past and future events. Despite recent efforts, capacity limits, their genesis and the underlying neural structures of visual working memory remain unclear. Here we show that performance in visual working memory - but not iconic visual memory - can be predicted by the strength of mental imagery as assessed with binocular rivalry in a given individual. In addition, for individuals with strong imagery, modulating the background luminance diminished performance on visual working memory and imagery tasks, but not working memory for number strings. This suggests that luminance signals were disrupting sensory-based imagery mechanisms and not a general working memory system. Individuals with poor imagery still performed above chance in the visual working memory task, but their performance was not affected by the background luminance, suggesting a dichotomy in strategies for visual working memory: individuals with strong mental imagery rely on sensory-based imagery to support mnemonic performance, while those with poor imagery rely on different strategies. These findings could help reconcile current controversy regarding the mechanism and location of visual mnemonic storage. PMID:22195024

Mental imagery and visual working memory.

PubMed

Keogh, Rebecca; Pearson, Joel

2011-01-01

Visual working memory provides an essential link between past and future events. Despite recent efforts, capacity limits, their genesis and the underlying neural structures of visual working memory remain unclear. Here we show that performance in visual working memory--but not iconic visual memory--can be predicted by the strength of mental imagery as assessed with binocular rivalry in a given individual. In addition, for individuals with strong imagery, modulating the background luminance diminished performance on visual working memory and imagery tasks, but not working memory for number strings. This suggests that luminance signals were disrupting sensory-based imagery mechanisms and not a general working memory system. Individuals with poor imagery still performed above chance in the visual working memory task, but their performance was not affected by the background luminance, suggesting a dichotomy in strategies for visual working memory: individuals with strong mental imagery rely on sensory-based imagery to support mnemonic performance, while those with poor imagery rely on different strategies. These findings could help reconcile current controversy regarding the mechanism and location of visual mnemonic storage.

Analysis of antigen-specific B-cell memory directly ex vivo.

PubMed

McHeyzer-Williams, Louise J; McHeyzer-Williams, Michael G

2004-01-01

Helper T-cell-regulated B-cell memory develops in response to initial antigen priming as a cellular product of the germinal center (GC) reaction. On antigen recall, memory response precursors expand rapidly with exaggerated differentiation into plasma cells to produce the high-titer, high-affinity antibody(Ab) that typifies the memory B-cell response in vivo. We have devised a high-resolution flow cytometric strategy to quantify the emergence and maintenance of antigen-specific memory B cells directly ex vivo. Extended cell surface phenotype establishes a level of cellular diversity not previously appreciated for the memory B-cell compartment. Using an "exclusion transfer" strategy, we ascertain the capacity of two distinct memory B-cell populations to transfer antigen-specific memory into naive adoptive hosts. Finally, we sequence expressed messenger ribonucleic acid (mRNA) from single cells within the population to estimate the level of somatic hypermutation as the best molecular indicator of B-cell memory. In this chapter, we describe the methods used in each of these four sections that serve to provide high-resolution quantification of antigen-specific B-cell memory responses directly ex vivo.

Rhesus monkeys employ a procedural strategy to reduce working memory load in a self-ordered spatial search task

PubMed Central

Taffe, Michael A.; Taffe, William J.

2011-01-01

Several nonhuman primate species have been reported to employ a distance-minimizing, traveling salesman-like, strategy during foraging as well as in experimental spatial search tasks involving lesser amounts of locomotion. Spatial sequencing may optimize performance by reducing reference or episodic memory loads, locomotor costs, competition or other demands. A computerized self-ordered spatial search (SOSS) memory task has been adapted from a human neuropsychological testing battery (CANTAB, Cambridge Cognition, Ltd) for use in monkeys. Accurate completion of a trial requires sequential responses to colored boxes in two or more spatial locations without repetition of a previous location. Marmosets have been reported to employ a circling pattern of search, suggesting spontaneous adoption of a strategy to reduce working memory load. In this study the SOSS performance of rhesus monkeys was assessed to determine if the use of a distance-minimizing search path enhances accuracy. A novel strategy score, independent of the trial difficulty and arrangement of boxes, has been devised. Analysis of the performance of 21 monkeys trained on SOSS over two years shows that a distance-minimizing search strategy is associated with improved accuracy. This effect is observed within individuals as they improve over many cumulative sessions of training on the task and across individuals at any given level of training. Erroneous trials were associated with a failure to deploy the strategy. It is concluded that the effect of utilizing the strategy on this locomotion-free, laboratory task is to enhance accuracy by reducing demands on spatial working memory resources. PMID:21840507

More memory under evolutionary learning may lead to chaos

NASA Astrophysics Data System (ADS)

Diks, Cees; Hommes, Cars; Zeppini, Paolo

2013-02-01

We show that an increase of memory of past strategy performance in a simple agent-based innovation model, with agents switching between costly innovation and cheap imitation, can be quantitatively stabilising while at the same time qualitatively destabilising. As memory in the fitness measure increases, the amplitude of price fluctuations decreases, but at the same time a bifurcation route to chaos may arise. The core mechanism leading to the chaotic behaviour in this model with strategy switching is that the map obtained for the system with memory is a convex combination of an increasing linear function and a decreasing non-linear function.

Level of Formal Thought and Organizational Memory Strategies.

ERIC Educational Resources Information Center

Wyatt, Kathryn B.; Geis, Mary Fulcher

1978-01-01

Early and late formal-operational adolescents having similar ages and IQs were presented tasks to assess their use of organizational memory strategies: multitrial free recall of unrelated and categorized words and a sorting task followed by free recall of the sorted words. (Author/SS)

Everyday memory strategies for medication adherence.

PubMed

Boron, Julie Blaskewicz; Rogers, Wendy A; Fisk, Arthur D

2013-01-01

The need to manage chronic diseases and multiple medications increases for many older adults. Older adults are aware of memory declines and incorporate compensatory techniques. Everyday memory strategies used to support medication adherence were investigated. A survey distributed to 2000 households in the Atlanta metropolitan area yielded a 19.9% response rate including 354 older adults, aged 60-80 years. Older adults reported forgetting to take their medications, more so as their activity deviated from normal routines, such as unexpected activities. The majority of older adults endorsed at least two compensatory strategies, which they perceived to be more helpful in normal routines. Compensatory strategies were associated with higher education, more medications, having concern, and self-efficacy to take medications. As memory changes, older adults rely on multiple cues, and perceive reliance on multiple cues to be helpful. These data have implications for the design and successful implementation of medication reminder systems and interventions. Copyright © 2013 Mosby, Inc. All rights reserved.

Working memory: a developmental study of phonological recoding.

PubMed

Palmer, S

2000-05-01

A cross-sectional study using children aged 3 to 7 years and a cross-sequential study using children aged between 5 and 8 years showed that the development of phonological recoding in working memory was more complex than the simple dichotomous picture portrayed in the current literature. It appears that initially children use no strategy in recall, which is proposed to represent the level of automatic activation of representations in long-term memory and the storage capacity of the central executive. This is followed by a period in which a visual strategy prevails, followed by a period of dual visual-verbal coding before the adult-like strategy of verbal coding finally emerges. The results are discussed in terms of three working memory models (Baddeley, 1990; Engle, 1996; Logie, 1996) where strategy use is seen as the development of attentional processes and phonological recoding as the development of inhibitory mechanisms in the central executive to suppress the habitual response set of visual coding.

Regional Differences in Brain Volume Predict the Acquisition of Skill in a Complex Real-Time Strategy Videogame

ERIC Educational Resources Information Center

Basak, Chandramallika; Voss, Michelle W.; Erickson, Kirk I.; Boot, Walter R.; Kramer, Arthur F.

2011-01-01

Previous studies have found that differences in brain volume among older adults predict performance in laboratory tasks of executive control, memory, and motor learning. In the present study we asked whether regional differences in brain volume as assessed by the application of a voxel-based morphometry technique on high resolution MRI would also…

Training working memory updating in young adults.

PubMed

Linares, Rocío; Borella, Erika; Lechuga, M Teresa; Carretti, Barbara; Pelegrina, Santiago

2018-05-01

Working memory updating (WMU) is a core mechanism in the human mental architecture and a good predictor of a wide range of cognitive processes. This study analyzed the benefits of two different WMU training procedures, near transfer effects on a working memory measure, and far transfer effects on nonverbal reasoning. Maintenance of any benefits a month later was also assessed. Participants were randomly assigned to: an adaptive training group that performed two numerical WMU tasks during four sessions; a non-adaptive training group that performed the same tasks but on a constant and less demanding level of difficulty; or an active control group that performed other tasks unrelated with working memory. After the training, all three groups showed improvements in most of the tasks, and these benefits were maintained a month later. The gain in one of the two WMU measures was larger for the adaptive and non-adaptive groups than for the control group. This specific gain in a task similar to the one trained would indicate the use of a better strategy for performing the task. Besides this nearest transfer effect, no other transfer effects were found. The adaptability of the training procedure did not produce greater improvements. These results are discussed in terms of the training procedure and the feasibility of training WMU.

Same task, different strategies: how brain networks can be influenced by memory strategy.

PubMed

Sanfratello, Lori; Caprihan, Arvind; Stephen, Julia M; Knoefel, Janice E; Adair, John C; Qualls, Clifford; Lundy, S Laura; Aine, Cheryl J

2014-10-01

Previous functional neuroimaging studies demonstrated that different neural networks underlie different types of cognitive processing by engaging participants in particular tasks, such as verbal or spatial working memory (WM) tasks. However, we report here that even when a WM task is defined as verbal or spatial, different types of memory strategies may be used to complete it, with concomitant variations in brain activity. We developed a questionnaire to characterize the type of strategy used by individual members in a group of 28 young healthy participants (18-25 years) during a spatial WM task. A cluster analysis was performed to differentiate groups. We acquired functional magnetoencephalography and structural diffusion tensor imaging measures to characterize the brain networks associated with the use of different strategies. We found two types of strategies were used during the spatial WM task, a visuospatial and a verbal strategy, and brain regions and time courses of activation differed between participants who used each. Task performance also varied by type of strategy used with verbal strategies showing an advantage. In addition, performance on neuropsychological tests (indices from Wechsler Adult Intelligence Scale-IV, Rey Complex Figure Test) correlated significantly with fractional anisotropy measures for the visuospatial strategy group in white matter tracts implicated in other WM and attention studies. We conclude that differences in memory strategy can have a pronounced effect on the locations and timing of brain activation and that these differences need further investigation as a possible confounding factor for studies using group averaging as a means for summarizing results. Copyright © 2014 Wiley Periodicals, Inc.

Motor transfer from map ocular exploration to locomotion during spatial navigation from memory.

PubMed

Demichelis, Alixia; Olivier, Gérard; Berthoz, Alain

2013-02-01

Spatial navigation from memory can rely on two different strategies: a mental simulation of a kinesthetic spatial navigation (egocentric route strategy) or visual-spatial memory using a mental map (allocentric survey strategy). We hypothesized that a previously performed "oculomotor navigation" on a map could be used by the brain to perform a locomotor memory task. Participants were instructed to (1) learn a path on a map through a sequence of vertical and horizontal eyes movements and (2) walk on the slabs of a "magic carpet" to recall this path. The main results showed that the anisotropy of ocular movements (horizontal ones being more efficient than vertical ones) influenced performances of participants when they change direction on the central slab of the magic carpet. These data suggest that, to find their way through locomotor space, subjects mentally repeated their past ocular exploration of the map, and this visuo-motor memory was used as a template for the locomotor performance.

Frontal and Parietal Cortices Show Different Spatiotemporal Dynamics across Problem-solving Stages.

PubMed

Tschentscher, Nadja; Hauk, Olaf

2016-08-01

Arithmetic problem-solving can be conceptualized as a multistage process ranging from task encoding over rule and strategy selection to step-wise task execution. Previous fMRI research suggested a frontal-parietal network involved in the execution of complex numerical and nonnumerical tasks, but evidence is lacking on the particular contributions of frontal and parietal cortices across time. In an arithmetic task paradigm, we evaluated individual participants' "retrieval" and "multistep procedural" strategies on a trial-by-trial basis and contrasted those in time-resolved analyses using combined EEG and MEG. Retrieval strategies relied on direct retrieval of arithmetic facts (e.g., 2 + 3 = 5). Procedural strategies required multiple solution steps (e.g., 12 + 23 = 12 + 20 + 3 or 23 + 10 + 2). Evoked source analyses revealed independent activation dynamics within the first second of problem-solving in brain areas previously described as one network, such as the frontal-parietal cognitive control network: The right frontal cortex showed earliest effects of strategy selection for multistep procedural strategies around 300 msec, before parietal cortex activated around 700 msec. In time-frequency source power analyses, memory retrieval and multistep procedural strategies were differentially reflected in theta, alpha, and beta frequencies: Stronger beta and alpha desynchronizations emerged for procedural strategies in right frontal, parietal, and temporal regions as function of executive demands. Arithmetic fact retrieval was reflected in right prefrontal increases in theta power. Our results demonstrate differential brain dynamics within frontal-parietal networks across the time course of a problem-solving process, and analyses of different frequency bands allowed us to disentangle cortical regions supporting the underlying memory and executive functions.

Levels-of-processing effect on internal source monitoring in schizophrenia

PubMed Central

RAGLAND, J. DANIEL; McCARTHY, ERIN; BILKER, WARREN B.; RENSINGER, COLLEEN M. B; VALDEZ, JEFFREY; KOHLER, CHRISTIAN; GUR, RAQUEL E.; GUR, RUBEN C.

2015-01-01

Background Recognition can be normalized in schizophrenia by providing patients with semantic organizational strategies through a levels-of-processing (LOP) framework. However, patients may rely primarily on familiarity effects, making recognition less sensitive than source monitoring to the strength of the episodic memory trace. The current study investigates whether providing semantic organizational strategies can also normalize patients’ internal source-monitoring performance. Method Sixteen clinically stable medicated patients with schizophrenia and 15 demographically matched healthy controls were asked to identify the source of remembered words following an LOP-encoding paradigm in which they alternated between processing words on a ‘shallow’ perceptual versus a ‘deep’ semantic level. A multinomial analysis provided orthogonal measures of item recognition and source discrimination, and bootstrapping generated variance to allow for parametric analyses. LOP and group effects were tested by contrasting recognition and source-monitoring parameters for words that had been encoded during deep versus shallow processing conditions. Results As in a previous study there were no group differences in LOP effects on recognition performance, with patients and controls benefiting equally from deep versus shallow processing. Although there were no group differences in internal source monitoring, only controls had significantly better performance for words processed during the deep encoding condition. Patient performance did not correlate with clinical symptoms or medication dose. Conclusions Providing a deep processing semantic encoding strategy significantly improved patients’ recognition performance only. The lack of a significant LOP effect on internal source monitoring in patients may reffect subtle problems in the relational binding of semantic information that are independent of strategic memory processes. PMID:16608558

Levels-of-processing effect on internal source monitoring in schizophrenia.

PubMed

Ragland, J Daniel; McCarthy, Erin; Bilker, Warren B; Brensinger, Colleen M; Valdez, Jeffrey; Kohler, Christian; Gur, Raquel E; Gur, Ruben C

2006-05-01

Recognition can be normalized in schizophrenia by providing patients with semantic organizational strategies through a levels-of-processing (LOP) framework. However, patients may rely primarily on familiarity effects, making recognition less sensitive than source monitoring to the strength of the episodic memory trace. The current study investigates whether providing semantic organizational strategies can also normalize patients' internal source-monitoring performance. Sixteen clinically stable medicated patients with schizophrenia and 15 demographically matched healthy controls were asked to identify the source of remembered words following an LOP-encoding paradigm in which they alternated between processing words on a 'shallow' perceptual versus a 'deep' semantic level. A multinomial analysis provided orthogonal measures of item recognition and source discrimination, and bootstrapping generated variance to allow for parametric analyses. LOP and group effects were tested by contrasting recognition and source-monitoring parameters for words that had been encoded during deep versus shallow processing conditions. As in a previous study there were no group differences in LOP effects on recognition performance, with patients and controls benefiting equally from deep versus shallow processing. Although there were no group differences in internal source monitoring, only controls had significantly better performance for words processed during the deep encoding condition. Patient performance did not correlate with clinical symptoms or medication dose. Providing a deep processing semantic encoding strategy significantly improved patients' recognition performance only. The lack of a significant LOP effect on internal source monitoring in patients may reflect subtle problems in the relational binding of semantic information that are independent of strategic memory processes.

Memory Is Not Only about Storage.

ERIC Educational Resources Information Center

Huber, Kay L.

1993-01-01

The Atkinson-Shiffrin model of memory has three components: sensory, short term, and long term. Each memory process (such as encoding, storage, and retrieval) can be linked to specific teaching and learning strategies. (SK)

Clinical Holistic Medicine: How to Recover Memory Without “Implanting” Memories in Your Patient

PubMed Central

Ventegodt, Søren; Kandel, Isack; Merrick, Joav

2007-01-01

Every therapeutic strategy and system teach us the philosophy of the treatment system to the patient, but often this teaching is subliminal and the philosophical impact must be seen as “implanted philosophy”, which gives distorted interpretations of past events called “implanted memories”. Based on the understanding of the connection between “implanted memory” and “implanted philosophy” we have developed a strategy for avoiding implanting memories arising from one of the seven most common causes of implanted memories in psychodynamic therapy: 1) Satisfying own expectancies, 2) pleasing the therapist, 3) transferences and counter transferences, 4) as source of mental and emotional order, 5) as emotional defence, 6) as symbol and 7) from implanted philosophy. Freud taught us that child sexuality is “polymorphously perverted”, meaning that all kinds of sexuality is present at least potentially with the little child; and in dreams consciousness often go back to the earlier stages of development, potentially causing all kinds of sexual dreams and fantasies, which can come up in therapy and look like real memories. The therapist working with psychodynamic psychotherapy, clinical holistic medicine, psychiatry, and emotionally oriented bodywork, should be aware of the danger of implanting philosophy and memories. Implanted memories and implanted philosophy must be carefully handled and de-learned before ending the therapy. In conclusion “clinical holistic medicine” has developed a strategy for avoiding implanting memories. PMID:17891319

[Individual differences in strategy use in the Japanese reading span test].

PubMed

Endo, Kaori; Osaka, Mariko

2012-02-01

Working memory is a system for processing and storing information. The Reading Span Test (RST), developed by Daneman and Carpenter (1980), is well-known for assessing individual difference in working memory. In the present investigation, we used the Japanese version of the RST (Osaka, 2002) and analyzed individual differences in strategy use from the viewpoint of strategy type (rehearsal, chaining, word-image, scene-image, and initial letter) and frequency of use (used in almost all trials, in half the trials, or not used). Data from the participants (N = 132) were assigned to groups according to the scores, for the total number of words correctly recalled and the proportion correct. The results showed that the frequency of word-image strategy use differed significantly between high-scoring subjects (HSS) and low-scoring subjects (LSS). HSS mainly used word-image and chaining strategies, while LSS used rehearsal and chaining strategies. This indicates that HSS used both verbal and visual strategies, whereas LSS relied only on verbal strategies. The use of the word-image is important for effective retention of words in memory.

Attentional control activation relates to working memory in attention-deficit/hyperactivity disorder.

PubMed

Burgess, Gregory C; Depue, Brendan E; Ruzic, Luka; Willcutt, Erik G; Du, Yiping P; Banich, Marie T

2010-04-01

Attentional control difficulties in individuals with attention-deficit/hyperactivity disorder (ADHD) might reflect poor working memory (WM) ability, especially because WM ability and attentional control rely on similar brain regions. The current study examined whether WM ability might explain group differences in brain activation between adults with ADHD and normal control subjects during attentional demand. Participants were 20 adults with ADHD combined subtype with no comorbid psychiatric or learning disorders and 23 control subjects similar in age, IQ, and gender. The WM measures were obtained from the Wechsler Adult Intelligence Scale-III and Wechsler Memory Scale-Revised. Brain activation was assessed with functional magnetic resonance imaging (fMRI) while performing a Color-Word Stroop task. Group differences in WM ability explained a portion of the activation in left dorsolateral prefrontal cortex (DLPFC), which has been related to the creation and maintenance of an attentional set for task-relevant information. In addition, greater WM ability predicted increased activation of brain regions related to stimulus-driven attention and response selection processes in the ADHD group but not in the control group. The inability to maintain an appropriate task set in young adults with combined type ADHD, associated with decreased activity in left DLPFC, might in part be due to poor WM ability. Furthermore, in individuals with ADHD, higher WM ability might relate to increased recruitment of stimulus-driven attention and response selection processes, perhaps as a compensatory strategy. Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Metacognitive awareness of learning strategies in undergraduates.

PubMed

McCabe, Jennifer

2011-04-01

Two studies examined undergraduates' metacognitive awareness of six empirically-supported learning strategies. Study 1 results overall suggested an inability to predict the learning outcomes of educational scenarios describing the strategies of dual-coding, static-media presentations, low-interest extraneous details, testing, and spacing; there was, however, weak endorsement of the strategy of generating one's own study materials. In addition, an independent measure of metacognitive self-regulation was correlated with scenario performance. Study 2 demonstrated higher prediction accuracy for students who had received targeted instruction on applied memory topics in their psychology courses, and the best performance for those students directly exposed to the original empirical studies from which the scenarios were derived. In sum, this research suggests that undergraduates are largely unaware of several specific strategies that could benefit memory for course information; further, training in applied learning and memory topics has the potential to improve metacognitive judgments in these domains.

Effects of strategy on visual working memory capacity

PubMed Central

Bengson, Jesse J.; Luck, Steven J.

2015-01-01

Substantial evidence suggests that individual differences in estimates of working memory capacity reflect differences in how effectively people use their intrinsic storage capacity. This suggests that estimated capacity could be increased by instructions that encourage more effective encoding strategies. The present study tested this by giving different participants explicit strategy instructions in a change detection task. Compared to a condition in which participants were simply told to do their best, we found that estimated capacity was increased for participants who were instructed to remember the entire visual display, even at set sizes beyond their capacity. However, no increase in estimated capacity was found for a group that was told to focus on a subset of the items in supracapacity arrays. This finding confirms the hypothesis that encoding strategies may influence visual working memory performance, and it is contrary to the hypothesis that the optimal strategy is to filter out any items beyond the storage capacity. PMID:26139356

Effects of strategy on visual working memory capacity.

PubMed

Bengson, Jesse J; Luck, Steven J

2016-02-01

Substantial evidence suggests that individual differences in estimates of working memory capacity reflect differences in how effectively people use their intrinsic storage capacity. This suggests that estimated capacity could be increased by instructions that encourage more effective encoding strategies. The present study tested this by giving different participants explicit strategy instructions in a change detection task. Compared to a condition in which participants were simply told to do their best, we found that estimated capacity was increased for participants who were instructed to remember the entire visual display, even at set sizes beyond their capacity. However, no increase in estimated capacity was found for a group that was told to focus on a subset of the items in supracapacity arrays. This finding confirms the hypothesis that encoding strategies may influence visual working memory performance, and it is contrary to the hypothesis that the optimal strategy is to filter out any items beyond the storage capacity.

Response strategies in list learning by orangutans (Pongo pygmaeus x P. abelii).

PubMed

Swartz, Karyl B; Himmanen, Sharon A; Shumaker, Robert W

2007-08-01

Rhesus monkeys (Macaca mulatta) develop strategies to acquire and execute serial lists (K. B. Swartz & S. A. Himmanen, 2001). Serial probe recognition studies of list memory have demonstrated similarities across monkeys and humans (S. F. Sands & A. A. Wright, 1980). The present study extended the investigation of list learning and memory to determine whether orangutans (Pongo pygmaeus x P. abelii) would show evidence of subjective organization of photographic lists in a manner similar to that shown by humans learning a list of unrelated words (E. Tulving, 1962). No evidence for the effective use of a subjective organization strategy was found, but the orangutans developed a right-to-left spatial response strategy, which emerged during the acquisition of 5-item lists. This strategy was an effective way to reduce the load on working memory when presented with a complex array of items.

Postnatal treadmill exercise alleviates short-term memory impairment by enhancing cell proliferation and suppressing apoptosis in the hippocampus of rat pups born to diabetic rats.

PubMed

Kim, Young Hoon; Sung, Yun-Hee; Lee, Hee-Hyuk; Ko, Il-Gyu; Kim, Sung-Eun; Shin, Mal-Soon; Kim, Bo-Kyun

2014-08-01

During pregnancy, diabetes mellitus exerts detrimental effects on the development of the fetus, especially the central nervous system. In the current study, we evaluated the effects of postnatal treadmill exercise on short-term memory in relation with cell proliferation and apoptosis in the hippocampus of rat pups born to streptozotocin (STZ)-induced diabetic maternal rats. Adult female rats were mated with male rats for 24 h. Two weeks after mating, the pregnant female rats were divided into two groups: control group and STZ injection group. The pregnant rats in the STZ injection group were administered 40 mg/kg of STZ intraperitoneally. After birth, the rat pups were divided into the following four groups: control group, control with postnatal exercise group, maternal STZ-injection group, and maternal STZ-injection with postnatal exercise group. The rat pups in the postnatal exercise groups were made to run on a treadmill for 30 min once a day, 5 times per week for 2 weeks beginning 4 weeks after birth. The rat pups born to diabetic rats were shown to have short-term memory impairment with suppressed cell proliferation and increased apoptosis in the hippocampal dentate gyrus. Postnatal treadmill exercise alleviated short-term memory impairment by increased cell proliferation and suppressed apoptosis in the rat pups born to diabetic rats. These findings indicate that postnatal treadmill exercise may be used as a valuable strategy to ameliorate neurodevelopmental problems in children born to diabetics.

Category learning strategies in younger and older adults: Rule abstraction and memorization.

PubMed

Wahlheim, Christopher N; McDaniel, Mark A; Little, Jeri L

2016-06-01

Despite the fundamental role of category learning in cognition, few studies have examined how this ability differs between younger and older adults. The present experiment examined possible age differences in category learning strategies and their effects on learning. Participants were trained on a category determined by a disjunctive rule applied to relational features. The utilization of rule- and exemplar-based strategies was indexed by self-reports and transfer performance. Based on self-reported strategies, the frequencies of rule- and exemplar-based learners were not significantly different between age groups, but there was a significantly higher frequency of intermediate learners (i.e., learners not identifying with a reliance on either rule- or exemplar-based strategies) in the older than younger adult group. Training performance was higher for younger than older adults regardless of the strategy utilized, showing that older adults were impaired in their ability to learn the correct rule or to remember exemplar-label associations. Transfer performance converged with strategy reports in showing higher fidelity category representations for younger adults. Younger adults with high working memory capacity were more likely to use an exemplar-based strategy, and older adults with high working memory capacity showed better training performance. Age groups did not differ in their self-reported memory beliefs, and these beliefs did not predict training strategies or performance. Overall, the present results contradict earlier findings that older adults prefer rule- to exemplar-based learning strategies, presumably to compensate for memory deficits. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Cognitive deficits are a matter of emotional context: inflexible strategy use mediates context-specific learning impairments in OCD.

PubMed

Zetsche, Ulrike; Rief, Winfried; Westermann, Stefan; Exner, Cornelia

2015-01-01

The present study examines the interplay between cognitive deficits and emotional context in obsessive-compulsive disorder (OCD) and social phobia (SP). Specifically, this study examines whether the inflexible use of efficient learning strategies in an emotional context underlies impairments in probabilistic classification learning (PCL) in OCD, and whether PCL impairments are specific to OCD. Twenty-three participants with OCD, 30 participants with SP and 30 healthy controls completed a neutral and an OCD-specific PCL task. OCD participants failed to adopt efficient learning strategies and showed fewer beneficial strategy switches than controls only in an OCD-specific context, but not in a neutral context. Additionally, OCD participants did not show any explicit memory impairments. Number of beneficial strategy switches in the OCD-specific task mediated the difference in PCL performance between OCD and control participants. Individuals with SP were impaired in both PCL tasks. In contrast to neuropsychological models postulating general cognitive impairments in OCD, the present findings suggest that it is the interaction between cognition and emotion that is impaired in OCD. Specifically, activated disorder-specific fears may impair the flexible adoption of efficient learning strategies and compromise otherwise unimpaired PCL. Impairments in PCL are not specific to OCD.

Working Memory Strategies during Rational Number Magnitude Processing

ERIC Educational Resources Information Center

Hurst, Michelle; Cordes, Sara

2017-01-01

Rational number understanding is a critical building block for success in more advanced mathematics; however, how rational number magnitudes are conceptualized is not fully understood. In the current study, we used a dual-task working memory (WM) interference paradigm to investigate the dominant type of strategy (i.e., requiring verbal WM…

Free Recall Test Experience Potentiates Strategy-Driven Effects of Value on Memory

ERIC Educational Resources Information Center

Cohen, Michael S.; Rissman, Jesse; Hovhannisyan, Mariam; Castel, Alan D.; Knowlton, Barbara J.

2017-01-01

People tend to show better memory for information that is deemed valuable or important. By one mechanism, individuals selectively engage deeper, semantic encoding strategies for high value items (Cohen, Rissman, Suthana, Castel, & Knowlton, 2014). By another mechanism, information paired with value or reward is automatically strengthened in…

Functional neuroimaging of sex differences in autobiographical memory recall in depression.

PubMed

Young, K D; Bodurka, J; Drevets, W C

2017-11-01

Females are more likely than males to develop major depressive disorder (MDD). The current study used fMRI to compare the neural correlates of autobiographical memory (AM) recall between males and females diagnosed with MDD. AM overgenerality is a persistent cognitive deficit in MDD, the magnitude of which is correlated with depressive severity only in females. Delineating the neurobiological correlates of this deficit may elucidate the nature of sex-differences in the diathesis for developing MDD. Participants included unmedicated males and females diagnosed with MDD (n = 20/group), and an age and sex matched healthy control group. AM recall in response to positive, negative, and neutral cue words was compared with a semantic memory task. The behavioral properties of AMs did not differ between MDD males and females. In contrast, main effects of sex on cerebral hemodynamic activity were observed in left dorsolateral prefrontal cortex and parahippocampal gyrus during recall of positive specific memories, and middle prefrontal cortex (mPFC), and precuneus during recall of negative specific memories. Moreover, main effects of diagnosis on regional hemodynamic activity were observed in left ventrolateral prefrontal cortex and mPFC during positive specific memory recall, and dorsal anterior cingulate cortex during negative specific memory recall. Sex × diagnosis interactions were evident in the dorsomedial prefrontal cortex, caudate, and precuneus during positive memory recall, and in the posterior cingulate cortex, insula, precuneus and thalamus during negative specific memory recall. The differential hemodynamic changes conceivably may reflect sex-specific cognitive strategies during recall of AMs irrespective of the phenomenological properties of those memories.

Aerobic exercise for Alzheimer's disease: A randomized controlled pilot trial

PubMed Central

Van Sciver, Angela; Mahnken, Jonathan D.; Honea, Robyn A.; Brooks, William M.; Billinger, Sandra A.; Swerdlow, Russell H.; Burns, Jeffrey M.

2017-01-01

Background There is increasing interest in the role of physical exercise as a therapeutic strategy for individuals with Alzheimer’s disease (AD). We assessed the effect of 26 weeks (6 months) of a supervised aerobic exercise program on memory, executive function, functional ability and depression in early AD. Methods and findings This study was a 26-week randomized controlled trial comparing the effects of 150 minutes per week of aerobic exercise vs. non-aerobic stretching and toning control intervention in individuals with early AD. A total of 76 well-characterized older adults with probable AD (mean age 72.9 [7.7]) were enrolled and 68 participants completed the study. Exercise was conducted with supervision and monitoring by trained exercise specialists. Neuropsychological tests and surveys were conducted at baseline,13, and 26 weeks to assess memory and executive function composite scores, functional ability (Disability Assessment for Dementia), and depressive symptoms (Cornell Scale for Depression in Dementia). Cardiorespiratory fitness testing and brain MRI was performed at baseline and 26 weeks. Aerobic exercise was associated with a modest gain in functional ability (Disability Assessment for Dementia) compared to individuals in the ST group (X2 = 8.2, p = 0.02). There was no clear effect of intervention on other primary outcome measures of Memory, Executive Function, or depressive symptoms. However, secondary analyses revealed that change in cardiorespiratory fitness was positively correlated with change in memory performance and bilateral hippocampal volume. Conclusions Aerobic exercise in early AD is associated with benefits in functional ability. Exercise-related gains in cardiorespiratory fitness were associated with improved memory performance and reduced hippocampal atrophy, suggesting cardiorespiratory fitness gains may be important in driving brain benefits. Trial registration ClinicalTrials.gov NCT01128361 PMID:28187125

Aerobic exercise for Alzheimer's disease: A randomized controlled pilot trial.

PubMed

Morris, Jill K; Vidoni, Eric D; Johnson, David K; Van Sciver, Angela; Mahnken, Jonathan D; Honea, Robyn A; Wilkins, Heather M; Brooks, William M; Billinger, Sandra A; Swerdlow, Russell H; Burns, Jeffrey M

2017-01-01

There is increasing interest in the role of physical exercise as a therapeutic strategy for individuals with Alzheimer's disease (AD). We assessed the effect of 26 weeks (6 months) of a supervised aerobic exercise program on memory, executive function, functional ability and depression in early AD. This study was a 26-week randomized controlled trial comparing the effects of 150 minutes per week of aerobic exercise vs. non-aerobic stretching and toning control intervention in individuals with early AD. A total of 76 well-characterized older adults with probable AD (mean age 72.9 [7.7]) were enrolled and 68 participants completed the study. Exercise was conducted with supervision and monitoring by trained exercise specialists. Neuropsychological tests and surveys were conducted at baseline,13, and 26 weeks to assess memory and executive function composite scores, functional ability (Disability Assessment for Dementia), and depressive symptoms (Cornell Scale for Depression in Dementia). Cardiorespiratory fitness testing and brain MRI was performed at baseline and 26 weeks. Aerobic exercise was associated with a modest gain in functional ability (Disability Assessment for Dementia) compared to individuals in the ST group (X2 = 8.2, p = 0.02). There was no clear effect of intervention on other primary outcome measures of Memory, Executive Function, or depressive symptoms. However, secondary analyses revealed that change in cardiorespiratory fitness was positively correlated with change in memory performance and bilateral hippocampal volume. Aerobic exercise in early AD is associated with benefits in functional ability. Exercise-related gains in cardiorespiratory fitness were associated with improved memory performance and reduced hippocampal atrophy, suggesting cardiorespiratory fitness gains may be important in driving brain benefits. ClinicalTrials.gov NCT01128361.

Information-integration category learning and the human uncertainty response.

PubMed

Paul, Erick J; Boomer, Joseph; Smith, J David; Ashby, F Gregory

2011-04-01

The human response to uncertainty has been well studied in tasks requiring attention and declarative memory systems. However, uncertainty monitoring and control have not been studied in multi-dimensional, information-integration categorization tasks that rely on non-declarative procedural memory. Three experiments are described that investigated the human uncertainty response in such tasks. Experiment 1 showed that following standard categorization training, uncertainty responding was similar in information-integration tasks and rule-based tasks requiring declarative memory. In Experiment 2, however, uncertainty responding in untrained information-integration tasks impaired the ability of many participants to master those tasks. Finally, Experiment 3 showed that the deficit observed in Experiment 2 was not because of the uncertainty response option per se, but rather because the uncertainty response provided participants a mechanism via which to eliminate stimuli that were inconsistent with a simple declarative response strategy. These results are considered in the light of recent models of category learning and metacognition.

Reducing the stochasticity of crystal nucleation to enable subnanosecond memory writing

NASA Astrophysics Data System (ADS)

Rao, Feng; Ding, Keyuan; Zhou, Yuxing; Zheng, Yonghui; Xia, Mengjiao; Lv, Shilong; Song, Zhitang; Feng, Songlin; Ronneberger, Ider; Mazzarello, Riccardo; Zhang, Wei; Ma, Evan

2017-12-01

Operation speed is a key challenge in phase-change random-access memory (PCRAM) technology, especially for achieving subnanosecond high-speed cache memory. Commercialized PCRAM products are limited by the tens of nanoseconds writing speed, originating from the stochastic crystal nucleation during the crystallization of amorphous germanium antimony telluride (Ge2Sb2Te5). Here, we demonstrate an alloying strategy to speed up the crystallization kinetics. The scandium antimony telluride (Sc0.2Sb2Te3) compound that we designed allows a writing speed of only 700 picoseconds without preprogramming in a large conventional PCRAM device. This ultrafast crystallization stems from the reduced stochasticity of nucleation through geometrically matched and robust scandium telluride (ScTe) chemical bonds that stabilize crystal precursors in the amorphous state. Controlling nucleation through alloy design paves the way for the development of cache-type PCRAM technology to boost the working efficiency of computing systems.

Reciprocity phase in various 2×2 games by agents equipped with two-memory length strategy encouraged by grouping for interaction and adaptation.

PubMed

Wakiyama, Motoya; Tanimoto, Jun

2011-01-01

This paper numerically investigates 2×2 games involving the Prisoner's Dilemma, Chicken, Hero, Leader, Stag Hunt, and Trivial Games in which agents have a strategy expressed by five-bit, two-memory length. Our motivation is to explore how grouping for game interaction and strategy adaptation influence ST reciprocity and R reciprocity (Tanimoto and Sagara, 2007a [Tanimoto, J., Sagara, H., 2007a. A study on emergence of coordinated alternating reciprocity in a 2×2 game with 2-memory length strategy. Biosystems 90(3), 728-737]. Enhanced R reciprocity is observed with the stronger grouping for game interaction when a relatively stronger grouping for strategy adaptation is assumed. On the other hand, enhanced ST reciprocity emerged with the stronger grouping for strategy adaptation when the relatively weaker grouping for game interaction is imposed. Our numerical experiment deals with those two groupings independently and dependently. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Improving Children's Working Memory and Classroom Performance

ERIC Educational Resources Information Center

St Clair-Thompson, Helen; Stevens, Ruth; Hunt, Alexandra; Bolder, Emma

2010-01-01

Previous research has demonstrated close relationships between working memory and children's scholastic attainment. The aim of the present study was to explore a method of improving working memory, using memory strategy training. Two hundred and fifty-four children aged five to eight years were tested on measures of the phonological loop,…

Memory compensation in older adults: the role of health, emotion regulation, and trait mindfulness.

PubMed

de Frias, Cindy M

2014-09-01

The current study examined associations between everyday memory compensation and 3 person-level resource domains (i.e., health, emotion regulation, and trait mindfulness) in older adults. In this cross-sectional study, 89 healthy, community-dwelling older adults (ages 51-85 years) completed the multidimensional Memory Compensation Questionnaire, along with measures of self-reported health status, emotion regulation strategies, and trait mindfulness. Hierarchical regressions (covarying for age, gender, and education) showed that poorer mental health (especially for older adults) and physical health functioning were related to using compensatory strategies (e.g., reliance on others and investment of time and effort) more frequently. Cognitive reappraisers reported using more internal mnemonic strategies. Conversely, having a more mindful predisposition was associated with less frequent use of compensatory strategies, especially for middle-aged adults. The results suggest that health-related quality of life, adaptive strategies to regulate emotions, and trait mindfulness are additional contexts that determine the degree of engagement in everyday memory compensation and ultimately to successful aging. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The relationship among unawareness of memory impairment, depression, and dementia in older adults with memory impairment in Singapore.

PubMed

Liu, Jianlin; Abdin, Edimansyah; Vaingankar, Janhavi A; Shafie, Saleha B; Jeyagurunathan, Anitha; Shahwan, Shazana; Magadi, Harish; Ng, Li Ling; Chong, Siow Ann; Subramaniam, Mythily

2017-11-01

Previous research has studied the relationships among unawareness of memory impairment, depression, and dementia in older adults with severe dementia, but it has not considered the associations and clinical implications at earlier stages of memory impairment. This study therefore sought to examine the relationship among unawareness of memory impairment, depression, and dementia in older adults with memory impairment in Singapore. The participants were 751 older adults with memory impairment in Singapore. They were assessed for objective and subjective memory loss, depression, and dementia severity. Participants' subjective memory loss was determined based on a self-appraisal question on memory, and their objective memory loss was calculated based on their performance on three cognitive tasks. Unawareness was assessed based on the contrast between subjective and objective memory loss. Descriptive statistics revealed a high prevalence of unawareness (80.4%). Logistic regression analysis revealed that gender and marital status were significantly associated with unawareness. Men (odds ratio (OR) = 2.5) and those who were divorced or separated (OR = 23.0) were more likely to be unaware than women and those who were married, respectively. After chronic conditions and demographic characteristics were controlled for, multivariate logistic regression analyses revealed that older adults with depression were less likely (OR = 0.2) to be unaware than those without depression. Unawareness was also related with dementia severity; older adults with questionable (OR = 0.3) and mild dementia (OR = 0.4) were less likely to be unaware than someone without dementia. Unawareness of memory impairment was common among older adults with memory impairment. However, unawareness may be the result of denial as a strategy for coping with memory loss of which the older adult is aware. Psychological care should be integrated into the overall treatment management of dementia to mitigate the possible risk of depression while increasing individual awareness of memory loss. © 2017 Japanese Psychogeriatric Society.

Peripheral CD4+ naïve/memory ratio is an independent predictor of survival in non-small cell lung cancer

PubMed Central

Yang, Peng; Ma, Junhong; Yang, Xin; Li, Wei

2017-01-01

Background To investigate the clinical significance of naïve T cells, memory T cells, CD45RA+CD45RO+ T cells, and naïve/memory ratio in non-small cell lung cancer (NSCLC) patients. Methods Pretreatment peripheral blood samples from 76 NSCLC patients and 28 age- and sex-matched healthy volunteers were collected and tested for immune cells by flow cytometry. We compared the expression of these immune cells between patients and healthy controls and evaluated their predictive roles for survival in NSCLC by cox proportional hazards model. Results Decreased naïve CD4+ T cells, naïve CD8+ T cells, CD4+ naïve/memory ratios and CD4+CD45RA+CD45RO+ T cells, and increased memory CD4+ T cells, were observed in 76 NSCLC patients compared to healthy volunteers. Univariate analysis revealed that elevated CD4+ naïve/memory ratio correlated with prolonged progression-free survival (P=0.013). Multivariate analysis confirmed its predictive role with a hazard ratio of 0.35 (95% confidence interval, 0.19-0.75, P=0.012). Conclusions Peripheral CD4+ naïve/memory ratio can be used as a predictive biomarker in NSCLC patients and used to optimize personalized treatment strategies. PMID:29137371

Reading time allocation strategies and working memory using rapid serial visual presentation.

PubMed

Busler, Jessica N; Lazarte, Alejandro A

2017-09-01

Rapid serial visual presentation (RSVP) is a useful method for controlling the timing of text presentations and studying how readers' characteristics, such as working memory (WM) and reading strategies for time allocation, influence text recall. In the current study, a modified version of RSVP (Moving Window RSVP [MW-RSVP]) was used to induce longer pauses at the ends of clauses and ends of sentences when reading texts with multiple embedded clauses. We studied if WM relates to allocation of time at end of clauses or sentences in a self-paced reading task and in 2 MW-RSVP reading conditions (Constant MW-RSVP and Paused MW-RSVP) in which the reading rate was kept constant or pauses were induced. Higher WM span readers were more affected by the restriction of time allocation in the MW-RSVP conditions. In addition, the recall of both higher and lower WM-span readers benefited from the paused MW-RSVP presentation. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Future thinking improves prospective memory performance and plan enactment in older adults.

PubMed

Altgassen, Mareike; Rendell, Peter G; Bernhard, Anka; Henry, Julie D; Bailey, Phoebe E; Phillips, Louise H; Kliegel, Matthias

2015-01-01

Efficient intention formation might improve prospective memory by reducing the need for resource-demanding strategic processes during the delayed performance interval. The present study set out to test this assumption and provides the first empirical assessment of whether imagining a future action improves prospective memory performance equivalently at different stages of the adult lifespan. Thus, younger (n = 40) and older (n = 40) adults were asked to complete the Dresden Breakfast Task, which required them to prepare breakfast in accordance with a set of rules and time restrictions. All participants began by generating a plan for later enactment; however, after making this plan, half of the participants were required to imagine themselves completing the task in the future (future thinking condition), while the other half received standard instructions (control condition). As expected, overall younger adults outperformed older adults. Moreover, both older and younger adults benefited equally from future thinking instructions, as reflected in a higher proportion of prospective memory responses and more accurate plan execution. Thus, for both younger and older adults, imagining the specific visual-spatial context in which an intention will later be executed may serve as an easy-to-implement strategy that enhances prospective memory function in everyday life.

The influence of training and experience on memory strategy.

PubMed

Patrick, John; Morgan, Phillip L; Smy, Victoria; Tiley, Leyanne; Seeby, Helen; Patrick, Tanya; Evans, Jonathan

2015-07-01

This paper investigates whether, and if so how much, prior training and experience overwrite the influence of the constraints of the task environment on strategy deployment. This evidence is relevant to the theory of soft constraints that focuses on the role of constraints in the task environment (Gray, Simms, Fu, & Schoelles, Psychological Review, 113: 461-482, 2006). The theory explains how an increase in the cost of accessing information induces a more memory-based strategy involving more encoding and planning. Experiments 1 and 3 adopt a traditional training and transfer design using the Blocks World Task in which participants were exposed to training trials involving a 2.5-s delay in accessing goal-state information before encountering transfer trials in which there was no access delay. The effect of prior training was assessed by the degree of memory-based strategy adopted in the transfer trials. Training with an access delay had a substantial carry-over effect and increased the subsequent degree of memory-based strategy adopted in the transfer environment. However, such effects do not necessarily occur if goal-state access cost in training is less costly than in transfer trials (Experiment 2). Experiment 4 used a fine-grained intra-trial design to examine the effect of experiencing access cost on one, two, or three occasions within the same trial and found that such experience on two consecutive occasions was sufficient to induce a more memory-based strategy. This paper establishes some effects of training that are relevant to the soft constraints theory and also discusses practical implications.

Generation of switched memory B cells in response to vaccination in Down syndrome children and their siblings.

PubMed

Valentini, Diletta; Marcellini, Valentina; Bianchi, Simona; Villani, Alberto; Facchini, Marzia; Donatelli, Isabella; Castrucci, Maria Rita; Marasco, Emiliano; Farroni, Chiara; Carsetti, Rita

2015-11-27

Immunodeficiency is an integral aspect of Down syndrome, as demonstrated by the increased susceptibility to infection of affected. Mortality is still higher than in general population, with respiratory infections among the major causes of death. As more people with Down syndrome are living today than ever before, it is indispensable to develop strategies to prevent and cure the associated disorders. Vaccination is the most successful instrument of preventive medicine. Special seasonal influenza and pneumococcal vaccination strategies have been designed for individuals with risk conditions of all ages. Down syndrome individuals are not included in the high-risk categories. We enrolled in our study 15 children with Down syndrome and their siblings, vaccinated for the first time with seasonal influenza vaccine and receiving a booster dose of a glyco-conjugated pneumococcal vaccine. We compared the immunological features and response to vaccination measuring serum antibody titers and frequency of specific memory B cells. We confirm that a severe reduction of switched memory B cells is always associated to Down syndrome. After primary vaccination Down syndrome children generate significantly less specific switched memory B cells than their siblings. The response to a booster dose of vaccine is instead comparable in both groups. The production of specific antibodies was equally effective in Down syndrome and controls both after primary and secondary immunization. Down syndrome individuals should be considered a high risk group, because of their increased susceptibility to infection and reduced number of switched memory B cells. Tailored vaccination protocols are needed in order to reduce their burden of infections throughout life. Copyright © 2015. Published by Elsevier Ltd.

An Event Related Potentials Study of Semantic Coherence Effect during Episodic Encoding in Schizophrenia Patients

PubMed Central

Blanchet, Alain; Lockman, Hazlin

2018-01-01

The objective of this electrophysiological study was to investigate the processing of semantic coherence during encoding in relation to episodic memory processes promoted at test, in schizophrenia patients, by using the N400 paradigm. Eighteen schizophrenia patients and 15 healthy participants undertook a recognition memory task. The stimuli consisted of pairs of words either semantically related or unrelated to a given category name (context). During encoding, both groups exhibited an N400 external semantic coherence effect. Healthy controls also showed an N400 internal semantic coherence effect, but this effect was not present in patients. At test, related stimuli were accompanied by an FN400 old/new effect in both groups and by a parietal old/new effect in the control group alone. In the patient group, external semantic coherence effect was associated with FN400, while, in the control group, it was correlated to the parietal old/new effect. Our results indicate that schizophrenia patients can process the contextual information at encoding to enhance familiarity process for related stimuli at test. Therefore, cognitive rehabilitation therapies targeting the implementation of semantic encoding strategies can mobilize familiarity which in turn can overcome the recollection deficit, promoting successful episodic memory performance in schizophrenia patients. PMID:29535872

The effects of working memory load and attention refocusing on delay discounting rates in alcohol use disorder with comorbid antisocial personality disorder.

PubMed

Gunn, Rachel L; Gerst, Kyle R; Lake, Allison J; Finn, Peter R

2018-02-01

Executive working memory capacity (eWMC) is central to adaptive decision-making. Research has revealed reduced eWMC and higher rates of impulsive decision making in individuals with alcohol use disorders (AUDs: DSM-IV Alcohol Dependence of Alcohol Abuse) and antisocial psychopathology (AP). Recent work has shown that placing a load on working memory (WM) further increases impulsive decision making on the delay discounting (DD) task in those with AUDs and AP. The current study examined the effects of an attention refocusing manipulation to offset the effects of this WM-load on DD rates in control subjects, those with AUDs without AP, and AUDs with AP (AUD-AP). Results revealed that 1) the AUD-AP group had higher DD rates (i.e., more impulsive decision-making) than the AUD group, followed by controls, and 2) attention refocusing after a load is placed on WM was associated with lower DD rates compared to the load without refocusing in both AUD groups, but not controls. Results suggest that refocusing attention after a cognitive load may be an effective cognitive strategy for reducing the impulsivity-enhancing effects of cognitive load on decision making in individuals with AUDs and AP. Copyright © 2017 Elsevier Inc. All rights reserved.

Benefits from an autobiographical memory facilitation programme in relapsing-remitting multiple sclerosis patients: a clinical and neuroimaging study.

PubMed

Ernst, Alexandra; Sourty, Marion; Roquet, Daniel; Noblet, Vincent; Gounot, Daniel; Blanc, Frédéric; de Seze, Jérôme; Manning, Liliann

2016-10-09

While the efficacy of mental visual imagery (MVI) to alleviate autobiographical memory (AM) impairment in multiple sclerosis (MS) patients has been documented, nothing is known about the brain changes sustaining that improvement. To explore this issue, 20 relapsing-remitting MS patients showing AM impairment were randomly assigned to two groups, experimental (n = 10), who underwent the MVI programme, and control (n = 10), who followed a sham verbal programme. Besides the stringent AM assessment, the patients underwent structural and functional MRI sessions, consisting in retrieving personal memories, within a pre-/post-facilitation study design. Only the experimental group showed a significant AM improvement in post-facilitation, accompanied by changes in brain activation (medial and lateral frontal regions), functional connectivity (posterior brain regions), and grey matter volume (parahippocampal gyrus). Minor activations and functional connectivity changes were observed in the control group. The MVI programme improved AM in MS patients leading to functional and structural changes reflecting (1) an increase reliance on brain regions sustaining a self-referential process; (2) a decrease of those reflecting an effortful research process; and (3) better use of neural resources in brain regions sustaining MVI. Functional changes reported in the control group likely reflected ineffective attempts to use the sham strategy in AM.

Parallel computing for probabilistic fatigue analysis

NASA Technical Reports Server (NTRS)

Sues, Robert H.; Lua, Yuan J.; Smith, Mark D.

1993-01-01

This paper presents the results of Phase I research to investigate the most effective parallel processing software strategies and hardware configurations for probabilistic structural analysis. We investigate the efficiency of both shared and distributed-memory architectures via a probabilistic fatigue life analysis problem. We also present a parallel programming approach, the virtual shared-memory paradigm, that is applicable across both types of hardware. Using this approach, problems can be solved on a variety of parallel configurations, including networks of single or multiprocessor workstations. We conclude that it is possible to effectively parallelize probabilistic fatigue analysis codes; however, special strategies will be needed to achieve large-scale parallelism to keep large number of processors busy and to treat problems with the large memory requirements encountered in practice. We also conclude that distributed-memory architecture is preferable to shared-memory for achieving large scale parallelism; however, in the future, the currently emerging hybrid-memory architectures will likely be optimal.

Airport Noise Control Strategies,

DTIC Science & Technology

1986-05-01

MONICA SMX SANTA MARIA PUBLIC, SANTA MARIA SNA JOHN WAYNE/ORANGE COUNTY, SANTA ANA SOL LAN CARLOS, SAN CARLOS CTS SONOMA COUNTY , SANTA ROSA SZP SANTA...RUNWAY SYSTEM TOTAL OPERATIONS 174827 CONTACT. NA STS SONOMA COUNTY SANTA ROSA, CA PREFERENTIAL RUNWAY SYSTEM INFORMAL FLIGHT OPERATION RESTRICTION...STS SONOMA COUNTY SANTA ROSA. CA SUN FRIEDMAN MEMORIAL HAILEY, ID SWF STEWART NEWBURGH, NY TED TETERBORO TETERBORO, NJ TLH TALLAHASSEE MUNICIPAL

Prenatal stress changes learning strategies in adulthood.

PubMed

Schwabe, Lars; Bohbot, Veronique D; Wolf, Oliver T

2012-11-01

It is well known that stressful experiences may shape hippocampus-dependent learning and memory processes. However, although most studies focused on the impact of stress at the time of learning or memory testing, very little is known about how stress during critical periods of brain development affects learning and memory later in life. In this study, we asked whether prenatal stress exposure may influence the engagement of hippocampus-dependent spatial learning strategies and caudate nucleus-dependent response learning strategies in later life. To this end, we tested healthy participants whose mothers had experienced major negative life events during their pregnancy in a virtual navigation task that can be solved by spatial and response strategies. We found that young adults with prenatal stress used rigid response learning strategies more often than flexible spatial learning strategies compared with participants whose mothers did not experience major negative life events during pregnancy. Individual differences in acute or chronic stress do not account for these findings. Our data suggest that the engagement of hippocampal and nonhippocampal learning strategies may be influenced by stress very early in life. Copyright © 2012 Wiley Periodicals, Inc.

Embedding Number-Combinations Practice Within Word-Problem Tutoring

PubMed Central

Powell, Sarah R.; Fuchs, Lynn S.; Fuchs, Douglas

2012-01-01

Two aspects of mathematics with which students with mathematics learning difficulty (MLD) often struggle are word problems and number-combination skills. This article describes a math program in which students receive instruction on using algebraic equations to represent the underlying problem structure for three word-problem types. Students also learn counting strategies for answering number combinations that they cannot retrieve from memory. Results from randomized-control trials indicated that embedding the counting strategies for number combinations produces superior word-problem and number-combination outcomes for students with MLD beyond tutoring programs that focus exclusively on number combinations or word problems. PMID:22661880

Embedding Number-Combinations Practice Within Word-Problem Tutoring.

PubMed

Powell, Sarah R; Fuchs, Lynn S; Fuchs, Douglas

2010-09-01

Two aspects of mathematics with which students with mathematics learning difficulty (MLD) often struggle are word problems and number-combination skills. This article describes a math program in which students receive instruction on using algebraic equations to represent the underlying problem structure for three word-problem types. Students also learn counting strategies for answering number combinations that they cannot retrieve from memory. Results from randomized-control trials indicated that embedding the counting strategies for number combinations produces superior word-problem and number-combination outcomes for students with MLD beyond tutoring programs that focus exclusively on number combinations or word problems.

Arity Raising in Manticore

NASA Astrophysics Data System (ADS)

Bergstrom, Lars; Reppy, John

Compilers for polymorphic languages are required to treat values in programs in an abstract and generic way at the source level. The challenges of optimizing the boxing of raw values, flattening of argument tuples, and raising the arity of functions that handle complex structures to reduce memory usage are old ones, but take on newfound import with processors that have twice as many registers. We present a novel strategy that uses both control-flow and type information to provide an arity raising implementation addressing these problems. This strategy is conservative - no matter the execution path, the transformed program will not perform extra operations.

Spatial working memory capacity predicts bias in estimates of location.

PubMed

Crawford, L Elizabeth; Landy, David; Salthouse, Timothy A

2016-09-01

Spatial memory research has attributed systematic bias in location estimates to a combination of a noisy memory trace with a prior structure that people impose on the space. Little is known about intraindividual stability and interindividual variation in these patterns of bias. In the current work, we align recent empirical and theoretical work on working memory capacity limits and spatial memory bias to generate the prediction that those with lower working memory capacity will show greater bias in memory of the location of a single item. Reanalyzing data from a large study of cognitive aging, we find support for this prediction. Fitting separate models to individuals' data revealed a surprising variety of strategies. Some were consistent with Bayesian models of spatial category use, however roughly half of participants biased estimates outward in a way not predicted by current models and others seemed to combine these strategies. These analyses highlight the importance of studying individuals when developing general models of cognition. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Spatial Working Memory Capacity Predicts Bias in Estimates of Location

PubMed Central

Crawford, L. Elizabeth; Landy, David H.; Salthouse, Timothy A.

2016-01-01

Spatial memory research has attributed systematic bias in location estimates to a combination of a noisy memory trace with a prior structure that people impose on the space. Little is known about intra-individual stability and inter-individual variation in these patterns of bias. In the current work we align recent empirical and theoretical work on working memory capacity limits and spatial memory bias to generate the prediction that those with lower working memory capacity will show greater bias in memory of the location of a single item. Reanalyzing data from a large study of cognitive aging, we find support for this prediction. Fitting separate models to individuals’ data revealed a surprising variety of strategies. Some were consistent with Bayesian models of spatial category use, however roughly half of participants biased estimates outward in a way not predicted by current models and others seemed to combine these strategies. These analyses highlight the importance of studying individuals when developing general models of cognition. PMID:26900708

At the intersection of attention and memory: the mechanistic role of the posterior parietal lobe in working memory

PubMed Central

Berryhill, Marian E.; Chein, Jason; Olson, Ingrid R.

2011-01-01

Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The pure storage hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the internal attention hypothesis proposes that the PPC functions as an attention-based storage and refreshing mechanism deployable as an alternative to material-specific rehearsal. These models were tested in patients with bilateral PPC lesions. Our findings discount the pure storage hypothesis because variables indexing storage capacity and longevity were not disproportionately affected by PPC damage. Instead, our data support the internal attention account by showing that (a) normal participants tend to use a rehearsal-based WM maintenance strategy for recall tasks but not for recognition tasks; (b) patients with PPC lesions performed normally on WM tasks that relied on material-specific rehearsal strategies but poorly on WM tasks that relied on attention-based maintenance strategies and patient strategy usage could be shifted by task or instructions; (c) patients’ memory deficits extended into the long-term domain. These findings suggest that the PPC maintains or shifts internal attention among the representations of items in WM. PMID:21345344

At the intersection of attention and memory: the mechanistic role of the posterior parietal lobe in working memory.

PubMed

Berryhill, Marian E; Chein, Jason; Olson, Ingrid R

2011-04-01

Portions of the posterior parietal cortex (PPC) play a role in working memory (WM) yet the precise mechanistic function of this region remains poorly understood. The pure storage hypothesis proposes that this region functions as a short-lived modality-specific memory store. Alternatively, the internal attention hypothesis proposes that the PPC functions as an attention-based storage and refreshing mechanism deployable as an alternative to material-specific rehearsal. These models were tested in patients with bilateral PPC lesions. Our findings discount the pure storage hypothesis because variables indexing storage capacity and longevity were not disproportionately affected by PPC damage. Instead, our data support the internal attention account by showing that (a) normal participants tend to use a rehearsal-based WM maintenance strategy for recall tasks but not for recognition tasks; (b) patients with PPC lesions performed normally on WM tasks that relied on material-specific rehearsal strategies but poorly on WM tasks that relied on attention-based maintenance strategies and patient strategy usage could be shifted by task or instructions; (c) patients' memory deficits extended into the long-term domain. These findings suggest that the PPC maintains or shifts internal attention among the representations of items in WM. Copyright © 2011 Elsevier Ltd. All rights reserved.

Crew Interface Analysis: Selected Articles on Space Human Factors Research, 1987 - 1991

DTIC Science & Technology

1993-07-01

recognitions to that distractor ) suggest that the perceptual type of the graph has a strong representation in memory . We found that both training with... processing strategy. If my goal were to compare the value of variables or (possibly) to compare a trend, I would select a perceptual strategy. If...be needed to determine specific processing models for different questions using the perceptual strategy. In addition, predictions about the memory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sancho Pitarch, Jose Carlos; Kerbyson, Darren; Lang, Mike

Increasing the core-count on current and future processors is posing critical challenges to the memory subsystem to efficiently handle concurrent memory requests. The current trend to cope with this challenge is to increase the number of memory channels available to the processor's memory controller. In this paper we investigate the effectiveness of this approach on the performance of parallel scientific applications. Specifically, we explore the trade-off between employing multiple memory channels per memory controller and the use of multiple memory controllers. Experiments conducted on two current state-of-the-art multicore processors, a 6-core AMD Istanbul and a 4-core Intel Nehalem-EP, for amore » wide range of production applications shows that there is a diminishing return when increasing the number of memory channels per memory controller. In addition, we show that this performance degradation can be efficiently addressed by increasing the ratio of memory controllers to channels while keeping the number of memory channels constant. Significant performance improvements can be achieved in this scheme, up to 28%, in the case of using two memory controllers with each with one channel compared with one controller with two memory channels.« less

The effects of aging on ERP correlates of source memory retrieval for self-referential information.

PubMed

Dulas, Michael R; Newsome, Rachel N; Duarte, Audrey

2011-03-04

Numerous behavioral studies have suggested that normal aging negatively affects source memory accuracy for various kinds of associations. Neuroimaging evidence suggests that less efficient retrieval processing (temporally delayed and attenuated) may contribute to these impairments. Previous aging studies have not compared source memory accuracy and corresponding neural activity for different kinds of source details; namely, those that have been encoded via a more or less effective strategy. Thus, it is not yet known whether encoding source details in a self-referential manner, a strategy suggested to promote successful memory in the young and old, may enhance source memory accuracy and reduce the commonly observed age-related changes in neural activity associated with source memory retrieval. Here, we investigated these issues by using event-related potentials (ERPs) to measure the effects of aging on the neural correlates of successful source memory retrieval ("old-new effects") for objects encoded either self-referentially or self-externally. Behavioral results showed that both young and older adults demonstrated better source memory accuracy for objects encoded self-referentially. ERP results showed that old-new effects onsetted earlier for self-referentially encoded items in both groups and that age-related differences in the onset latency of these effects were reduced for self-referentially, compared to self-externally, encoded items. These results suggest that the implementation of an effective encoding strategy, like self-referential processing, may lead to more efficient retrieval, which in turn may improve source memory accuracy in both young and older adults. Published by Elsevier B.V.

Memory and Energy Optimization Strategies for Multithreaded Operating System on the Resource-Constrained Wireless Sensor Node

PubMed Central

Liu, Xing; Hou, Kun Mean; de Vaulx, Christophe; Xu, Jun; Yang, Jianfeng; Zhou, Haiying; Shi, Hongling; Zhou, Peng

2015-01-01

Memory and energy optimization strategies are essential for the resource-constrained wireless sensor network (WSN) nodes. In this article, a new memory-optimized and energy-optimized multithreaded WSN operating system (OS) LiveOS is designed and implemented. Memory cost of LiveOS is optimized by using the stack-shifting hybrid scheduling approach. Different from the traditional multithreaded OS in which thread stacks are allocated statically by the pre-reservation, thread stacks in LiveOS are allocated dynamically by using the stack-shifting technique. As a result, memory waste problems caused by the static pre-reservation can be avoided. In addition to the stack-shifting dynamic allocation approach, the hybrid scheduling mechanism which can decrease both the thread scheduling overhead and the thread stack number is also implemented in LiveOS. With these mechanisms, the stack memory cost of LiveOS can be reduced more than 50% if compared to that of a traditional multithreaded OS. Not is memory cost optimized, but also the energy cost is optimized in LiveOS, and this is achieved by using the multi-core “context aware” and multi-core “power-off/wakeup” energy conservation approaches. By using these approaches, energy cost of LiveOS can be reduced more than 30% when compared to the single-core WSN system. Memory and energy optimization strategies in LiveOS not only prolong the lifetime of WSN nodes, but also make the multithreaded OS feasible to run on the memory-constrained WSN nodes. PMID:25545264