WorldWideScience

Sample records for memory mental computations

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-09-01

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

  3. Mental images in episodic memory

    OpenAIRE

    Han, KyungHun

    2009-01-01

    Episodic memory, i.e. memorization of information within a spatiotemporal environment, is affected by Alzheimer's disease (AD) but its loss may also occur in the normal aging process. The purpose of this study is to analyze and evaluate episodic memory in patients with AD by examining their cognitive skills in episodic memory through the introspection technique. A new method was used, wherein we assessed mental images of the subject's own past recalled in the mind like projected pictures and ...

  4. Media, Mental Imagery, and Memory.

    Science.gov (United States)

    Clark, Robert L.

    1978-01-01

    Thirty-two students at the University of Oregon were tested to determine the effects of media on mental imagery and memory. The model incorporates a dual coding hypothesis, and five single and multiple channel treatments were used. (Author/JEG)

  5. Memory updating and mental arithmetic

    Directory of Open Access Journals (Sweden)

    Cheng-Ching eHan

    2016-02-01

    Full Text Available Is domain-general memory updating ability predictive of calculation skills or are such skills better predicted by the capacity for updating specifically numerical information? Here, we used multidigit mental multiplication (MMM as a measure for calculating skill as this operation requires the accurate maintenance and updating of information in addition to skills needed for arithmetic more generally. In Experiment 1, we found that only individual differences with regard to a task updating numerical information following addition (MUcalc could predict the performance of MMM, perhaps owing to common elements between the task and MMM. In Experiment 2, new updating tasks were designed to clarify this: a spatial updating task with no numbers, a numerical task with no calculation, and a word task. The results showed that both MUcalc and the spatial task were able to predict the performance of MMM but only with the more difficult problems, while other updating tasks did not predict performance. It is concluded that relevant processes involved in updating the contents of working memory support mental arithmetic in adults.

  6. Mental Imagery and Visual Working Memory

    OpenAIRE

    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 ...

  7. A computational model for evaluating the effects of attention, memory, and mental models on situation assessment of nuclear power plant operators

    International Nuclear Information System (INIS)

    Lee, Hyun-Chul; Seong, Poong-Hyun

    2009-01-01

    Operators in nuclear power plants have to acquire information from human system interfaces (HSIs) and the environment in order to create, update, and confirm their understanding of a plant state, as failures of situation assessment may cause wrong decisions for process control and finally errors of commission in nuclear power plants. A few computational models that can be used to predict and quantify the situation awareness of operators have been suggested. However, these models do not sufficiently consider human characteristics for nuclear power plant operators. In this paper, we propose a computational model for situation assessment of nuclear power plant operators using a Bayesian network. This model incorporates human factors significantly affecting operators' situation assessment, such as attention, working memory decay, and mental model. As this proposed model provides quantitative results of situation assessment and diagnostic performance, we expect that this model can be used in the design and evaluation of human system interfaces as well as the prediction of situation awareness errors in the human reliability analysis.

  8. A computational model for evaluating the effects of attention, memory, and mental models on situation assessment of nuclear power plant operators

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun-Chul [Instrumentation and Control/Human Factors Division, Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)], E-mail: leehc@kaeri.re.kr; Seong, Poong-Hyun [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2009-11-15

    Operators in nuclear power plants have to acquire information from human system interfaces (HSIs) and the environment in order to create, update, and confirm their understanding of a plant state, as failures of situation assessment may cause wrong decisions for process control and finally errors of commission in nuclear power plants. A few computational models that can be used to predict and quantify the situation awareness of operators have been suggested. However, these models do not sufficiently consider human characteristics for nuclear power plant operators. In this paper, we propose a computational model for situation assessment of nuclear power plant operators using a Bayesian network. This model incorporates human factors significantly affecting operators' situation assessment, such as attention, working memory decay, and mental model. As this proposed model provides quantitative results of situation assessment and diagnostic performance, we expect that this model can be used in the design and evaluation of human system interfaces as well as the prediction of situation awareness errors in the human reliability analysis.

  9. Mental Imagery and Visual Working Memory

    Science.gov (United States)

    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

  10. Mental imagery and visual working memory.

    Directory of Open Access Journals (Sweden)

    Rebecca Keogh

    Full Text Available 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.

  11. Mental imagery and visual working memory.

    Science.gov (United States)

    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.

  12. Self-Testing Computer Memory

    Science.gov (United States)

    Chau, Savio, N.; Rennels, David A.

    1988-01-01

    Memory system for computer repeatedly tests itself during brief, regular interruptions of normal processing of data. Detects and corrects transient faults as single-event upsets (changes in bits due to ionizing radiation) within milliseconds after occuring. Self-testing concept surpasses conventional by actively flushing latent defects out of memory and attempting to correct before accumulating beyond capacity for self-correction or detection. Cost of improvement modest increase in complexity of circuitry and operating time.

  13. Distributed-memory matrix computations

    DEFF Research Database (Denmark)

    Balle, Susanne Mølleskov

    1995-01-01

    The main goal of this project is to investigate, develop, and implement algorithms for numerical linear algebra on parallel computers in order to acquire expertise in methods for parallel computations. An important motivation for analyzaing and investigating the potential for parallelism in these......The main goal of this project is to investigate, develop, and implement algorithms for numerical linear algebra on parallel computers in order to acquire expertise in methods for parallel computations. An important motivation for analyzaing and investigating the potential for parallelism...... in these algorithms is that many scientific applications rely heavily on the performance of the involved dense linear algebra building blocks. Even though we consider the distributed-memory as well as the shared-memory programming paradigm, the major part of the thesis is dedicated to distributed-memory architectures....... We emphasize distributed-memory massively parallel computers - such as the Connection Machines model CM-200 and model CM-5/CM-5E - available to us at UNI-C and at Thinking Machines Corporation. The CM-200 was at the time this project started one of the few existing massively parallel computers...

  14. Computational modelling of memory retention from synapse to behaviour

    Science.gov (United States)

    van Rossum, Mark C. W.; Shippi, Maria

    2013-03-01

    One of our most intriguing mental abilities is the capacity to store information and recall it from memory. Computational neuroscience has been influential in developing models and concepts of learning and memory. In this tutorial review we focus on the interplay between learning and forgetting. We discuss recent advances in the computational description of the learning and forgetting processes on synaptic, neuronal, and systems levels, as well as recent data that open up new challenges for statistical physicists.

  15. Computational modelling of memory retention from synapse to behaviour

    International Nuclear Information System (INIS)

    Van Rossum, Mark C W; Shippi, Maria

    2013-01-01

    One of our most intriguing mental abilities is the capacity to store information and recall it from memory. Computational neuroscience has been influential in developing models and concepts of learning and memory. In this tutorial review we focus on the interplay between learning and forgetting. We discuss recent advances in the computational description of the learning and forgetting processes on synaptic, neuronal, and systems levels, as well as recent data that open up new challenges for statistical physicists. (paper)

  16. Dynamic computing random access memory

    International Nuclear Information System (INIS)

    Traversa, F L; Bonani, F; Pershin, Y V; Di Ventra, M

    2014-01-01

    The present von Neumann computing paradigm involves a significant amount of information transfer between a central processing unit and memory, with concomitant limitations in the actual execution speed. However, it has been recently argued that a different form of computation, dubbed memcomputing (Di Ventra and Pershin 2013 Nat. Phys. 9 200–2) and inspired by the operation of our brain, can resolve the intrinsic limitations of present day architectures by allowing for computing and storing of information on the same physical platform. Here we show a simple and practical realization of memcomputing that utilizes easy-to-build memcapacitive systems. We name this architecture dynamic computing random access memory (DCRAM). We show that DCRAM provides massively-parallel and polymorphic digital logic, namely it allows for different logic operations with the same architecture, by varying only the control signals. In addition, by taking into account realistic parameters, its energy expenditures can be as low as a few fJ per operation. DCRAM is fully compatible with CMOS technology, can be realized with current fabrication facilities, and therefore can really serve as an alternative to the present computing technology. (paper)

  17. Cognitive engineering in mental health computing

    NARCIS (Netherlands)

    Brinkman, W.P.

    2011-01-01

    Computer applications in support of mental health care and rehabilitation are becoming more widely used. They include technologies such as virtual reality, electronic diaries, multimedia, brain computing and computer games. Research in this area is emerging, and focussing on a variety of issues,

  18. The computational nature of memory modification.

    Science.gov (United States)

    Gershman, Samuel J; Monfils, Marie-H; Norman, Kenneth A; Niv, Yael

    2017-03-15

    Retrieving a memory can modify its influence on subsequent behavior. We develop a computational theory of memory modification, according to which modification of a memory trace occurs through classical associative learning, but which memory trace is eligible for modification depends on a structure learning mechanism that discovers the units of association by segmenting the stream of experience into statistically distinct clusters (latent causes). New memories are formed when the structure learning mechanism infers that a new latent cause underlies current sensory observations. By the same token, old memories are modified when old and new sensory observations are inferred to have been generated by the same latent cause. We derive this framework from probabilistic principles, and present a computational implementation. Simulations demonstrate that our model can reproduce the major experimental findings from studies of memory modification in the Pavlovian conditioning literature.

  19. The computational nature of memory modification

    Science.gov (United States)

    Gershman, Samuel J; Monfils, Marie-H; Norman, Kenneth A; Niv, Yael

    2017-01-01

    Retrieving a memory can modify its influence on subsequent behavior. We develop a computational theory of memory modification, according to which modification of a memory trace occurs through classical associative learning, but which memory trace is eligible for modification depends on a structure learning mechanism that discovers the units of association by segmenting the stream of experience into statistically distinct clusters (latent causes). New memories are formed when the structure learning mechanism infers that a new latent cause underlies current sensory observations. By the same token, old memories are modified when old and new sensory observations are inferred to have been generated by the same latent cause. We derive this framework from probabilistic principles, and present a computational implementation. Simulations demonstrate that our model can reproduce the major experimental findings from studies of memory modification in the Pavlovian conditioning literature. DOI: http://dx.doi.org/10.7554/eLife.23763.001 PMID:28294944

  20. Mental Rotation Ability and Computer Game Experience

    Science.gov (United States)

    Gecu, Zeynep; Cagiltay, Kursat

    2015-01-01

    Computer games, which are currently very popular among students, can affect different cognitive abilities. The purpose of the present study is to examine undergraduate students' experiences and preferences in playing computer games as well as their mental rotation abilities. A total of 163 undergraduate students participated. The results showed a…

  1. Parallel structures in human and computer memory

    Science.gov (United States)

    Kanerva, Pentti

    1986-08-01

    If we think of our experiences as being recorded continuously on film, then human memory can be compared to a film library that is indexed by the contents of the film strips stored in it. Moreover, approximate retrieval cues suffice to retrieve information stored in this library: We recognize a familiar person in a fuzzy photograph or a familiar tune played on a strange instrument. This paper is about how to construct a computer memory that would allow a computer to recognize patterns and to recall sequences the way humans do. Such a memory is remarkably similar in structure to a conventional computer memory and also to the neural circuits in the cortex of the cerebellum of the human brain. The paper concludes that the frame problem of artificial intelligence could be solved by the use of such a memory if we were able to encode information about the world properly.

  2. Human Memory Organization for Computer Programs.

    Science.gov (United States)

    Norcio, A. F.; Kerst, Stephen M.

    1983-01-01

    Results of study investigating human memory organization in processing of computer programming languages indicate that algorithmic logic segments form a cognitive organizational structure in memory for programs. Statement indentation and internal program documentation did not enhance organizational process of recall of statements in five Fortran…

  3. Computing betweenness centrality in external memory

    DEFF Research Database (Denmark)

    Arge, Lars; Goodrich, Michael T.; Walderveen, Freek van

    2013-01-01

    Betweenness centrality is one of the most well-known measures of the importance of nodes in a social-network graph. In this paper we describe the first known external-memory and cache-oblivious algorithms for computing betweenness centrality. We present four different external-memory algorithms...

  4. Computer Icons and the Art of Memory.

    Science.gov (United States)

    McNair, John R.

    1996-01-01

    States that key aspects of "memoria," the ancient Art of Memory, especially its focus on vivid representational images set against distinct backgrounds, can be helpful in creating memorable, universal, and easily retrievable computer icons. (PA)

  5. Memory Reconsolidation and Computational Learning

    Science.gov (United States)

    2010-03-01

    Siegelmann-Danieli and H.T. Siegelmann, "Robust Artificial Life Via Artificial Programmed Death," Artificial Inteligence 172(6-7), April 2008: 884-898. F...STATEMENT Unrestricted 13. SUPPLEMENTARY NOTES 20100402019 14. ABSTRACT Memory models are central to Artificial Intelligence and Machine...beyond [1]. The advances cited are a significant step toward creating Artificial Intelligence via neural networks at the human level. Our network

  6. Explicit mentalizing mechanisms and their adaptive role in memory conformity.

    Directory of Open Access Journals (Sweden)

    Rebecca Wheeler

    Full Text Available Memory conformity occurs when an individual endorses what other individuals remember about past events. Research on memory conformity is currently dominated by a 'forensic' perspective, which views the phenomenon as inherently undesirable. This is because conformity not only distorts the accuracy of an individual's memory, but also produces false corroboration between individuals, effects that act to undermine criminal justice systems. There is growing awareness, however, that memory conformity may be interpreted more generally as an adaptive social behavior regulated by explicit mentalizing mechanisms. Here, we provide novel evidence in support of this emerging alternative theoretical perspective. We carried out a memory conformity experiment which revealed that explicit belief-simulation (i.e. using one's own beliefs to model what other people believe systematically biases conformity towards like-minded individuals, even when there is no objective evidence that they have a more accurate memory than dissimilar individuals. We suggest that this bias is functional, i.e. adaptive, to the extent that it fosters trust, and hence cooperation, between in-group versus out-group individuals. We conclude that memory conformity is, in more fundamental terms, a highly desirable product of explicit mentalizing mechanisms that promote adaptive forms of social learning and cooperation.

  7. Explicit mentalizing mechanisms and their adaptive role in memory conformity.

    Science.gov (United States)

    Wheeler, Rebecca; Allan, Kevin; Tsivilis, Dimitris; Martin, Douglas; Gabbert, Fiona

    2013-01-01

    Memory conformity occurs when an individual endorses what other individuals remember about past events. Research on memory conformity is currently dominated by a 'forensic' perspective, which views the phenomenon as inherently undesirable. This is because conformity not only distorts the accuracy of an individual's memory, but also produces false corroboration between individuals, effects that act to undermine criminal justice systems. There is growing awareness, however, that memory conformity may be interpreted more generally as an adaptive social behavior regulated by explicit mentalizing mechanisms. Here, we provide novel evidence in support of this emerging alternative theoretical perspective. We carried out a memory conformity experiment which revealed that explicit belief-simulation (i.e. using one's own beliefs to model what other people believe) systematically biases conformity towards like-minded individuals, even when there is no objective evidence that they have a more accurate memory than dissimilar individuals. We suggest that this bias is functional, i.e. adaptive, to the extent that it fosters trust, and hence cooperation, between in-group versus out-group individuals. We conclude that memory conformity is, in more fundamental terms, a highly desirable product of explicit mentalizing mechanisms that promote adaptive forms of social learning and cooperation.

  8. Resistive content addressable memory based in-memory computation architecture

    KAUST Repository

    Salama, Khaled N.; Zidan, Mohammed A.; Kurdahi, Fadi; Eltawil, Ahmed M.

    2016-01-01

    Various examples are provided examples related to resistive content addressable memory (RCAM) based in-memory computation architectures. In one example, a system includes a content addressable memory (CAM) including an array of cells having a memristor based crossbar and an interconnection switch matrix having a gateless memristor array, which is coupled to an output of the CAM. In another example, a method, includes comparing activated bit values stored a key register with corresponding bit values in a row of a CAM, setting a tag bit value to indicate that the activated bit values match the corresponding bit values, and writing masked key bit values to corresponding bit locations in the row of the CAM based on the tag bit value.

  9. Resistive content addressable memory based in-memory computation architecture

    KAUST Repository

    Salama, Khaled N.

    2016-12-08

    Various examples are provided examples related to resistive content addressable memory (RCAM) based in-memory computation architectures. In one example, a system includes a content addressable memory (CAM) including an array of cells having a memristor based crossbar and an interconnection switch matrix having a gateless memristor array, which is coupled to an output of the CAM. In another example, a method, includes comparing activated bit values stored a key register with corresponding bit values in a row of a CAM, setting a tag bit value to indicate that the activated bit values match the corresponding bit values, and writing masked key bit values to corresponding bit locations in the row of the CAM based on the tag bit value.

  10. The mental health consequences of student "Holocaust memorial journeys".

    Science.gov (United States)

    Mimouni-Bloch, Aviva; Walter, Garry; Ross, Sharon; Bloch, Yuval

    2013-08-01

    Our aim was to study the mental health consequences of Israeli adolescents' 8-day "Holocaust memorial journey" to Poland. A survey to ascertain the experience of Israeli child and adolescent psychiatrists and residents in the specialty was conducted. Participants were asked about referrals regarding the memorial journey, and to compare these cases with referrals for other potentially traumatic events, including school "sleep-out" trips. Fifty child and adolescent psychiatrists and residents participated. According to their collective experience, the adolescents' memorial journey triggered a variety of mental health problems, including psychosis, but only one case of post-traumatic stress disorder (PTSD). Judging by the number of referrals, there was a higher rate of mental health problems following the memorial journey than after the annual sleep-out school trip. Although it may seldom lead to PTSD, the Holocaust memorial journey can be a major stressor for some participating teenagers. Evaluating "high risk" adolescents prior to their planned exposure to likely stressors and conducting large, prospective studies that examine the impact of pre-planned stressors on the lives of adolescents are warranted. Providing support to all adolescents before, during and after exposure to anticipated stressors is important.

  11. Associative Memory Computing Power and Its Simulation

    CERN Document Server

    Volpi, G; The ATLAS collaboration

    2014-01-01

    The associative memory (AM) system is a computing device made of hundreds of AM ASICs chips designed to perform “pattern matching” at very high speed. Since each AM chip stores a data base of 130000 pre-calculated patterns and large numbers of chips can be easily assembled together, it is possible to produce huge AM banks. Speed and size of the system are crucial for real-time High Energy Physics applications, such as the ATLAS Fast TracKer (FTK) Processor. Using 80 million channels of the ATLAS tracker, FTK finds tracks within 100 micro seconds. The simulation of such a parallelized system is an extremely complex task if executed in commercial computers based on normal CPUs. The algorithm performance is limited, due to the lack of parallelism, and in addition the memory requirement is very large. In fact the AM chip uses a content addressable memory (CAM) architecture. Any data inquiry is broadcast to all memory elements simultaneously, thus data retrieval time is independent of the database size. The gr...

  12. Associative Memory computing power and its simulation

    CERN Document Server

    Ancu, L S; The ATLAS collaboration; Britzger, D; Giannetti, P; Howarth, J W; Luongo, C; Pandini, C; Schmitt, S; Volpi, G

    2014-01-01

    The associative memory (AM) system is a computing device made of hundreds of AM ASICs chips designed to perform “pattern matching” at very high speed. Since each AM chip stores a data base of 130000 pre-calculated patterns and large numbers of chips can be easily assembled together, it is possible to produce huge AM banks. Speed and size of the system are crucial for real-time High Energy Physics applications, such as the ATLAS Fast TracKer (FTK) Processor. Using 80 million channels of the ATLAS tracker, FTK finds tracks within 100 micro seconds. The simulation of such a parallelized system is an extremely complex task if executed in commercial computers based on normal CPUs. The algorithm performance is limited, due to the lack of parallelism, and in addition the memory requirement is very large. In fact the AM chip uses a content addressable memory (CAM) architecture. Any data inquiry is broadcast to all memory elements simultaneously, thus data retrieval time is independent of the database size. The gr...

  13. Mental Schemas Hamper Memory Storage of Goal-Irrelevant Information.

    Science.gov (United States)

    Sweegers, C C G; Coleman, G A; van Poppel, E A M; Cox, R; Talamini, L M

    2015-01-01

    Mental schemas exert top-down control on information processing, for instance by facilitating the storage of schema-related information. However, given capacity-limits and competition in neural network processing, schemas may additionally exert their effects by suppressing information with low momentary relevance. In particular, when existing schemas suffice to guide goal-directed behavior, this may actually reduce encoding of the redundant sensory input, in favor of gaining efficiency in task performance. The present experiment set out to test this schema-induced shallow encoding hypothesis. Our approach involved a memory task in which faces had to be coupled to homes. For half of the faces the responses could be guided by a pre-learned schema, for the other half of the faces such a schema was not available. Memory storage was compared between schema-congruent and schema-incongruent items. To characterize putative schema effects, memory was assessed both with regard to visual details and contextual aspects of each item. The depth of encoding was also assessed through an objective neural measure: the parietal old/new ERP effect. This ERP effect, observed between 500-800 ms post-stimulus onset, is thought to reflect the extent of recollection: the retrieval of a vivid memory, including various contextual details from the learning episode. We found that schema-congruency induced substantial impairments in item memory and even larger ones in context memory. Furthermore, the parietal old/new ERP effect indicated higher recollection for the schema-incongruent than the schema-congruent memories. The combined findings indicate that, when goals can be achieved using existing schemas, this can hinder the in-depth processing of novel input, impairing the formation of perceptually detailed and contextually rich memory traces. Taking into account both current and previous findings, we suggest that schemas can both positively and negatively bias the processing of sensory input

  14. Alternative conceptions, memory, & mental models in physics education

    Science.gov (United States)

    Lee, Gyoungho; Shin, Jongho; Park, Jiyeon; Song, Sangho; Kim, Yeounsoo; Bao, Lei

    2005-09-01

    There are two somewhat independent research traditions, which converge to suggest a form of students' knowledge: alternative conceptions and mental models. However we have little literature that explains what they are different from each other and from memory. This study tried to describe these issues with some thoughts about how cognitive psychology and science education approaches can be best synthesized in order to approach these questions.

  15. Distributed Memory Parallel Computing with SEAWAT

    Science.gov (United States)

    Verkaik, J.; Huizer, S.; van Engelen, J.; Oude Essink, G.; Ram, R.; Vuik, K.

    2017-12-01

    Fresh groundwater reserves in coastal aquifers are threatened by sea-level rise, extreme weather conditions, increasing urbanization and associated groundwater extraction rates. To counteract these threats, accurate high-resolution numerical models are required to optimize the management of these precious reserves. The major model drawbacks are long run times and large memory requirements, limiting the predictive power of these models. Distributed memory parallel computing is an efficient technique for reducing run times and memory requirements, where the problem is divided over multiple processor cores. A new Parallel Krylov Solver (PKS) for SEAWAT is presented. PKS has recently been applied to MODFLOW and includes Conjugate Gradient (CG) and Biconjugate Gradient Stabilized (BiCGSTAB) linear accelerators. Both accelerators are preconditioned by an overlapping additive Schwarz preconditioner in a way that: a) subdomains are partitioned using Recursive Coordinate Bisection (RCB) load balancing, b) each subdomain uses local memory only and communicates with other subdomains by Message Passing Interface (MPI) within the linear accelerator, c) it is fully integrated in SEAWAT. Within SEAWAT, the PKS-CG solver replaces the Preconditioned Conjugate Gradient (PCG) solver for solving the variable-density groundwater flow equation and the PKS-BiCGSTAB solver replaces the Generalized Conjugate Gradient (GCG) solver for solving the advection-diffusion equation. PKS supports the third-order Total Variation Diminishing (TVD) scheme for computing advection. Benchmarks were performed on the Dutch national supercomputer (https://userinfo.surfsara.nl/systems/cartesius) using up to 128 cores, for a synthetic 3D Henry model (100 million cells) and the real-life Sand Engine model ( 10 million cells). The Sand Engine model was used to investigate the potential effect of the long-term morphological evolution of a large sand replenishment and climate change on fresh groundwater resources

  16. Mental rotation and working memory in musicians' dystonia.

    Science.gov (United States)

    Erro, Roberto; Hirschbichler, Stephanie T; Ricciardi, Lucia; Ryterska, Agata; Antelmi, Elena; Ganos, Christos; Cordivari, Carla; Tinazzi, Michele; Edwards, Mark J; Bhatia, Kailash P

    2016-11-01

    Mental rotation of body parts engages cortical-subcortical areas that are actually involved in the execution of a movement. Musicians' dystonia is a type of focal hand dystonia that is grouped together with writer's cramp under the rubric of "occupational dystonia", but it is unclear to which extent these two disorders share common pathophysiological mechanisms. Previous research has demonstrated patients with writer's cramp to have deficits in mental rotation of body parts. It is unknown whether patients with musicians' dystonia would display similar deficits, reinforcing the concept of shared pathophysiology. Eight patients with musicians' dystonia and eight healthy musicians matched for age, gender and musical education, performed a number of tasks assessing mental rotation of body parts and objects as well as verbal and spatial working memories abilities. There were no differences between patients and healthy musicians as to accuracy and reaction times in any of the tasks. Patients with musicians' dystonia have intact abilities in mentally rotating body parts, suggesting that this disorder relies on a highly selective disruption of movement planning and execution that manifests only upon playing a specific instrument. We further demonstrated that mental rotation of body parts and objects engages, at least partially, different cognitive networks. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Mental Time Travel, Memory and the Social Learning Strategies Tournament

    Science.gov (United States)

    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…

  18. The role of the hippocampus in memory and mental construction.

    Science.gov (United States)

    Sheldon, Signy; Levine, Brian

    2016-04-01

    Much has been learned about the processes that support the remembrance of past autobiographical episodes and their importance for a number of cognitive tasks. This work has focused on hippocampal contributions to constructing coherent mental representations of scenarios for these tasks, which has opened up new questions about the underlying hippocampal mechanisms. We propose a new framework to answer these questions, which incorporates task demands that prompt hippocampal contributions to mental construction, the online formation of such mental representations, and how these demands relate to the functional organization of the hippocampus. Synthesizing findings from autobiographical memory research, our framework suggests that the interaction of two task characteristics influences the recruitment of the hippocampus: (1) the degree of task open-endedness (quantified by the presence/absence of a retrieval framework) and (2) the degree to which the integration of perceptual details is required. These characteristics inform the relative weighting of anterior and posterior hippocampal involvement, following an organizational model in which the anterior and posterior hippocampus support constructions on the basis of conceptual and perceptual representations, respectively. The anticipated outcome of our framework is a refined understanding of hippocampal contributions to memory and to the host of related cognitive functions. © 2016 New York Academy of Sciences.

  19. Interference from mere thinking: mental rehearsal temporarily disrupts recall of motor memory.

    Science.gov (United States)

    Yin, Cong; Wei, Kunlin

    2014-08-01

    Interference between successively learned tasks is widely investigated to study motor memory. However, how simultaneously learned motor memories interact with each other has been rarely studied despite its prevalence in daily life. Assuming that motor memory shares common neural mechanisms with declarative memory system, we made unintuitive predictions that mental rehearsal, as opposed to further practice, of one motor memory will temporarily impair the recall of another simultaneously learned memory. Subjects simultaneously learned two sensorimotor tasks, i.e., visuomotor rotation and gain. They retrieved one memory by either practice or mental rehearsal and then had their memory evaluated. We found that mental rehearsal, instead of execution, impaired the recall of unretrieved memory. This impairment was content-independent, i.e., retrieving either gain or rotation impaired the other memory. Hence, conscious recollection of one motor memory interferes with the recall of another memory. This is analogous to retrieval-induced forgetting in declarative memory, suggesting a common neural process across memory systems. Our findings indicate that motor imagery is sufficient to induce interference between motor memories. Mental rehearsal, currently widely regarded as beneficial for motor performance, negatively affects memory recall when it is exercised for a subset of memorized items. Copyright © 2014 the American Physiological Society.

  20. Paging memory from random access memory to backing storage in a parallel computer

    Science.gov (United States)

    Archer, Charles J; Blocksome, Michael A; Inglett, Todd A; Ratterman, Joseph D; Smith, Brian E

    2013-05-21

    Paging memory from random access memory (`RAM`) to backing storage in a parallel computer that includes a plurality of compute nodes, including: executing a data processing application on a virtual machine operating system in a virtual machine on a first compute node; providing, by a second compute node, backing storage for the contents of RAM on the first compute node; and swapping, by the virtual machine operating system in the virtual machine on the first compute node, a page of memory from RAM on the first compute node to the backing storage on the second compute node.

  1. Process optimization mental capacity and memory in schoolchildren

    Directory of Open Access Journals (Sweden)

    Kaminska T.M.

    2016-03-01

    Full Text Available Purpose — increase the processes of mental capacity, antioxidant and detoxication effects in the schoolchildren of different regions of residence the use of succinic acid. Patients and methods. Studies conducted in 3 groups of 30 children 7–10 years who took the drug succinic acid for 1 month 1 — villages Irpen region; 2 — industrial city; 3 — c. Kyiv. Results. Prior preparation course that includes succinic acid, the number of missed days at school on acute and recurrent respiratory infections during the month rehabilitation was: in group 1 — 7.4±1.5 days; in group 2 — 8.8±1.9 days; in group 3 — 5.6±0.7 days. After taking the drug significantly decreased frequency of morbidity and amounted to: in group 1 (1.4±0.2 days; in group 2 — 1.8±0.2 days; 3 group — 1.2±0.1 days. The drug was well tolerated by children, side effects were not observed. There was a rapid improvement in visual memory and RAM memory content in all groups of children. Under the influence of the drug significantly reduced glutathione system performance decreases level of superoxide dismutase, increases antioxidant activity, detected reduction of level glutathione-S-transferase in serum indicates increasing detoxification function of the liver. Conclusions. Severe detoxification effect of succinic acid and its ability to activate the functional processes and mental efficiency allows to recommen the reception of preparation by annually improvement of progress at school, memory and disability rates.

  2. Mental Capacity and Working Memory in Chemistry: Algorithmic "versus" Open-Ended Problem Solving

    Science.gov (United States)

    St Clair-Thompson, Helen; Overton, Tina; Bugler, Myfanwy

    2012-01-01

    Previous research has revealed that problem solving and attainment in chemistry are constrained by mental capacity and working memory. However, the terms mental capacity and working memory come from different theories of cognitive resources, and are assessed using different tasks. The current study examined the relationships between mental…

  3. Memory systems, computation, and the second law of thermodynamics

    International Nuclear Information System (INIS)

    Wolpert, D.H.

    1992-01-01

    A memory is a physical system for transferring information form one moment in time to another, where that information concerns something external to the system itself. This paper argues on information-theoretic and statistical mechanical grounds that useful memories must be of one of two types, exemplified by memory in abstract computer programs and by memory in photographs. Photograph-type memories work by exploring a collapse of state space flow to an attractor state. (This attractor state is the open-quotes initializedclose quotes state of the memory.) The central assumption of the theory of reversible computation tells us that in any such collapsing, regardless of whether the collapsing must increase in entropy of the system. In concert with the second law, this establishes the logical necessity of the empirical observation that photograph-type memories are temporally asymmetric (they can tell us about the past but not about the future). Under the assumption that human memory is a photograph-type memory, this result also explains why we humans can remember only our past and not our future. In contrast to photo-graph-type memories, computer-type memories do not require any initialization, and therefore are not directly affected by the second law. As a result, computer memories can be of the future as easily as of the past, even if the program running on the computer is logically irreversible. This is entirely in accord with the well-known temporal reversibility of the process of computation. This paper ends by arguing that the asymmetry of the psychological arrow of time is a direct consequence of the asymmetry of human memory. With the rest of this paper, this explains, explicitly and rigorously, why the psychological and thermodynamic arrows of time are correlated with one another. 24 refs

  4. Amorphous Semiconductors: From Photocatalyst to Computer Memory

    Science.gov (United States)

    Sundararajan, Mayur

    encouraging but inconclusive. Then the method was successfully demonstrated on mesoporous TiO2SiO 2 by showing a shift in its optical bandgap. One of the special class of amorphous semiconductors is chalcogenide glasses, which exhibit high ionic conductivity even at room temperature. When metal doped chalcogenide glasses are under an electric field, they become electronically conductive. These properties are exploited in the computer memory storage application of Conductive Bridging Random Access Memory (CBRAM). CBRAM is a non-volatile memory that is a strong contender to replace conventional volatile RAMs such as DRAM, SRAM, etc. This technology has already been commercialized, but the working mechanism is still not clearly understood especially the nature of the conductive bridge filament. In this project, the CBRAM memory cells are fabricated by thermal evaporation method with Agx(GeSe 2)1-x as the solid electrolyte layer, Ag as the active electrode and Au as the inert electrode. By careful use of cyclic voltammetry, the conductive filaments were grown on the surface and the bulk of the solid electrolyte. The comparison between the two filaments revealed major differences leading to contradiction with the existing working mechanism. After compiling all the results, a modified working mechanism is proposed. SAXS is a powerful tool to characterize nanostructure of glasses. The analysis of the SAXS data to get useful information are usually performed by different programs. In this project, Irena and GIFT programs were compared by performing the analysis of the SAXS data of glass and glass ceramics samples. Irena was shown to be not suitable for the analysis of SAXS data that has a significant contribution from interparticle interactions. GIFT was demonstrated to be better suited for such analysis. Additionally, the results obtained by programs for samples with low interparticle interactions were shown to be consistent.

  5. Large scale particle simulations in a virtual memory computer

    International Nuclear Information System (INIS)

    Gray, P.C.; Million, R.; Wagner, J.S.; Tajima, T.

    1983-01-01

    Virtual memory computers are capable of executing large-scale particle simulations even when the memory requirements exceeds the computer core size. The required address space is automatically mapped onto slow disc memory the the operating system. When the simulation size is very large, frequent random accesses to slow memory occur during the charge accumulation and particle pushing processes. Assesses to slow memory significantly reduce the excecution rate of the simulation. We demonstrate in this paper that with the proper choice of sorting algorithm, a nominal amount of sorting to keep physically adjacent particles near particles with neighboring array indices can reduce random access to slow memory, increase the efficiency of the I/O system, and hence, reduce the required computing time. (orig.)

  6. A simplified computational memory model from information processing

    Science.gov (United States)

    Zhang, Lanhua; Zhang, Dongsheng; Deng, Yuqin; Ding, Xiaoqian; Wang, Yan; Tang, Yiyuan; Sun, Baoliang

    2016-01-01

    This paper is intended to propose a computational model for memory from the view of information processing. The model, called simplified memory information retrieval network (SMIRN), is a bi-modular hierarchical functional memory network by abstracting memory function and simulating memory information processing. At first meta-memory is defined to express the neuron or brain cortices based on the biology and graph theories, and we develop an intra-modular network with the modeling algorithm by mapping the node and edge, and then the bi-modular network is delineated with intra-modular and inter-modular. At last a polynomial retrieval algorithm is introduced. In this paper we simulate the memory phenomena and functions of memorization and strengthening by information processing algorithms. The theoretical analysis and the simulation results show that the model is in accordance with the memory phenomena from information processing view. PMID:27876847

  7. A simplified computational memory model from information processing.

    Science.gov (United States)

    Zhang, Lanhua; Zhang, Dongsheng; Deng, Yuqin; Ding, Xiaoqian; Wang, Yan; Tang, Yiyuan; Sun, Baoliang

    2016-11-23

    This paper is intended to propose a computational model for memory from the view of information processing. The model, called simplified memory information retrieval network (SMIRN), is a bi-modular hierarchical functional memory network by abstracting memory function and simulating memory information processing. At first meta-memory is defined to express the neuron or brain cortices based on the biology and graph theories, and we develop an intra-modular network with the modeling algorithm by mapping the node and edge, and then the bi-modular network is delineated with intra-modular and inter-modular. At last a polynomial retrieval algorithm is introduced. In this paper we simulate the memory phenomena and functions of memorization and strengthening by information processing algorithms. The theoretical analysis and the simulation results show that the model is in accordance with the memory phenomena from information processing view.

  8. Influences of multiple memory systems on auditory mental image acuity.

    Science.gov (United States)

    Navarro Cebrian, Ana; Janata, Petr

    2010-05-01

    The influence of different memory systems and associated attentional processes on the acuity of auditory images, formed for the purpose of making intonation judgments, was examined across three experiments using three different task types (cued-attention, imagery, and two-tone discrimination). In experiment 1 the influence of implicit long-term memory for musical scale structure was manipulated by varying the scale degree (leading tone versus tonic) of the probe note about which a judgment had to be made. In experiments 2 and 3 the ability of short-term absolute pitch knowledge to develop was manipulated by presenting blocks of trials in the same key or in seven different keys. The acuity of auditory images depended on all of these manipulations. Within individual listeners, thresholds in the two-tone discrimination and cued-attention conditions were closely related. In many listeners, cued-attention thresholds were similar to thresholds in the imagery condition, and depended on the amount of training individual listeners had in playing a musical instrument. The results indicate that mental images formed at a sensory/cognitive interface for the purpose of making perceptual decisions are highly malleable.

  9. Computer Needs of Severely Mentally Retarded Persons.

    Science.gov (United States)

    Flanagan, Kelly

    1982-01-01

    The article reviews technology applicable for use by severely mentally retarded learners. Descriptions are given of assistive devices (including communication aids), controls and interfaces (such as single switch access to standard software), and software (including games to teach cause and effect and simple matching and counting). (CL)

  10. The Spacetime Memory of Geometric Phases and Quantum Computing

    CERN Document Server

    Binder, B

    2002-01-01

    Spacetime memory is defined with a holonomic approach to information processing, where multi-state stability is introduced by a non-linear phase-locked loop. Geometric phases serve as the carrier of physical information and geometric memory (of orientation) given by a path integral measure of curvature that is periodically refreshed. Regarding the resulting spin-orbit coupling and gauge field, the geometric nature of spacetime memory suggests to assign intrinsic computational properties to the electromagnetic field.

  11. Evaluation of Auditory Sensory Memory of Mentally Retarded and Nonretarded Persons.

    Science.gov (United States)

    Campbell, Edward M.; Meyer, Philip A.

    1981-01-01

    Performance of mildly mentally retarded and nonretarded persons was compared in two experiments designed to identify processes of auditory sensory memory. A theoretical model was proposed to incorporate the current pattern of results. (Author)

  12. Static Memory Deduplication for Performance Optimization in Cloud Computing

    Directory of Open Access Journals (Sweden)

    Gangyong Jia

    2017-04-01

    Full Text Available In a cloud computing environment, the number of virtual machines (VMs on a single physical server and the number of applications running on each VM are continuously growing. This has led to an enormous increase in the demand of memory capacity and subsequent increase in the energy consumption in the cloud. Lack of enough memory has become a major bottleneck for scalability and performance of virtualization interfaces in cloud computing. To address this problem, memory deduplication techniques which reduce memory demand through page sharing are being adopted. However, such techniques suffer from overheads in terms of number of online comparisons required for the memory deduplication. In this paper, we propose a static memory deduplication (SMD technique which can reduce memory capacity requirement and provide performance optimization in cloud computing. The main innovation of SMD is that the process of page detection is performed offline, thus potentially reducing the performance cost, especially in terms of response time. In SMD, page comparisons are restricted to the code segment, which has the highest shared content. Our experimental results show that SMD efficiently reduces memory capacity requirement and improves performance. We demonstrate that, compared to other approaches, the cost in terms of the response time is negligible.

  13. Static Memory Deduplication for Performance Optimization in Cloud Computing.

    Science.gov (United States)

    Jia, Gangyong; Han, Guangjie; Wang, Hao; Yang, Xuan

    2017-04-27

    In a cloud computing environment, the number of virtual machines (VMs) on a single physical server and the number of applications running on each VM are continuously growing. This has led to an enormous increase in the demand of memory capacity and subsequent increase in the energy consumption in the cloud. Lack of enough memory has become a major bottleneck for scalability and performance of virtualization interfaces in cloud computing. To address this problem, memory deduplication techniques which reduce memory demand through page sharing are being adopted. However, such techniques suffer from overheads in terms of number of online comparisons required for the memory deduplication. In this paper, we propose a static memory deduplication (SMD) technique which can reduce memory capacity requirement and provide performance optimization in cloud computing. The main innovation of SMD is that the process of page detection is performed offline, thus potentially reducing the performance cost, especially in terms of response time. In SMD, page comparisons are restricted to the code segment, which has the highest shared content. Our experimental results show that SMD efficiently reduces memory capacity requirement and improves performance. We demonstrate that, compared to other approaches, the cost in terms of the response time is negligible.

  14. Mental model construction, not just memory, is a central component of cognitive change in psychotherapy.

    Science.gov (United States)

    von Hecker, Ulrich; McIntosh, Daniel N; Sedek, Grzegorz

    2015-01-01

    We challenge the idea that a cognitive perspective on therapeutic change concerns only memory processes. We argue that inclusion of impairments in more generative cognitive processes is necessary for complete understanding of cases such as depression. In such cases what is identified in the target article as an "integrative memory structure" is crucially supported by processes of mental model construction.

  15. Veridical and False Pictorial Memory in Individuals with and without Mental Retardation

    Science.gov (United States)

    Carlin, Michael T.; Toglia, Michael P.; Wakeford, Yvonne; Jakway, Allison; Sullivan, Kate; Hasel, Lisa

    2008-01-01

    Veridical and false pictorial recognition were assessed in individuals with mental retardation; groups were matched for MA and CA. Pictures were viewed in either a generative or static format at acquisition. The individuals with mental retardation and those in the MA-matched group had higher rates of false memories for critical items and lower hit…

  16. Deficits in episodic memory and mental time travel in patients with post-traumatic stress disorder.

    Science.gov (United States)

    Zlomuzica, Armin; Woud, Marcella L; Machulska, Alla; Kleimt, Katharina; Dietrich, Lisa; Wolf, Oliver T; Assion, Hans-Joerg; Huston, Joseph P; De Souza Silva, Maria A; Dere, Ekrem; Margraf, Jürgen

    2018-04-20

    Post-traumatic stress disorder (PTSD) is characterized by impairments in mnestic functions, especially in the domain of episodic memory. These alterations might affect different aspects of episodic memory functioning. Here we tested PTSD patients and healthy controls (matched for age, sex and education) in a newly developed virtual reality episodic memory test (VR-EMT), a test for mental time travel, episodic future thinking, and prospective memory (M3xT). In a cross-validation experiment, their performance was further evaluated in the Rivermead Behavioral Memory Test (RBMT). PTSD patients demonstrated impairments in episodic memory formation and mental time travel and showed difficulties in utilizing information from episodic memory to solve problems. Diminished attention and concentration in PTSD did not account for performance deficits in these tasks but higher levels of negative arousal were found in PTSD patients. Furthermore, performance in the VR-EMT and RBMT in PTSD patients correlated negatively with self-reported measures of stress and depression. Our results suggest that deficits in episodic memory formation and mental time travel in PTSD lead to difficulties in utilizing the content of episodic memories for solving problems in the present or to plan future behavior. Clinical implications of these findings and suggestions for cognitive-behavioral treatment of PTSD are discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Mental representation and mental practice: experimental investigation on the functional links between motor memory and motor imagery.

    Directory of Open Access Journals (Sweden)

    Cornelia Frank

    Full Text Available Recent research on mental representation of complex action has revealed distinct differences in the structure of representational frameworks between experts and novices. More recently, research on the development of mental representation structure has elicited functional changes in novices' representations as a result of practice. However, research investigating if and how mental practice adds to this adaptation process is lacking. In the present study, we examined the influence of mental practice (i.e., motor imagery rehearsal on both putting performance and the development of one's representation of the golf putt during early skill acquisition. Novice golfers (N = 52 practiced the task of golf putting under one of four different practice conditions: mental, physical, mental-physical combined, and no practice. Participants were tested prior to and after a practice phase, as well as after a three day retention interval. Mental representation structures of the putt were measured, using the structural dimensional analysis of mental representation. This method provides psychometric data on the distances and groupings of basic action concepts in long-term memory. Additionally, putting accuracy and putting consistency were measured using two-dimensional error scores of each putt. Findings revealed significant performance improvements over the course of practice together with functional adaptations in mental representation structure. Interestingly, after three days of practice, the mental representations of participants who incorporated mental practice into their practice regime displayed representation structures that were more similar to a functional structure than did participants who did not incorporate mental practice. The findings of the present study suggest that mental practice promotes the cognitive adaptation process during motor learning, leading to more elaborate representations than physical practice only.

  18. Associative Memory computing power and its simulation.

    CERN Document Server

    Volpi, G; The ATLAS collaboration

    2014-01-01

    The associative memory (AM) chip is ASIC device specifically designed to perform ``pattern matching'' at very high speed and with parallel access to memory locations. The most extensive use for such device will be the ATLAS Fast Tracker (FTK) processor, where more than 8000 chips will be installed in 128 VME boards, specifically designed for high throughput in order to exploit the chip's features. Each AM chip will store a database of about 130000 pre-calculated patterns, allowing FTK to use about 1 billion patterns for the whole system, with any data inquiry broadcast to all memory elements simultaneously within the same clock cycle (10 ns), thus data retrieval time is independent of the database size. Speed and size of the system are crucial for real-time High Energy Physics applications, such as the ATLAS FTK processor. Using 80 million channels of the ATLAS tracker, FTK finds tracks within 100 $\\mathrm{\\mu s}$. The simulation of such a parallelized system is an extremely complex task when executed in comm...

  19. Computing visibility on terrains in external memory

    NARCIS (Netherlands)

    Haverkort, H.J.; Toma, L.; Zhuang, Yi

    2007-01-01

    We describe a novel application of the distribution sweeping technique to computing visibility on terrains. Given an arbitrary viewpoint v, the basic problem we address is computing the visibility map or viewshed of v, which is the set of points in the terrain that are visible from v. We give the

  20. An Intervention Study on Mental Computation for Second Graders in Taiwan

    Science.gov (United States)

    Yang, Der-Ching; Huang, Ke-Lun

    2014-01-01

    The authors compared the mental computation performance and mental strategies used by an experimental Grade 2 class and a control Grade 2 class before and after instructional intervention. Results indicate that students in the experimental group had better performance on mental computation. The use of mental strategies (counting, separation,…

  1. Fellow travellers: Working memory and mental time travel in rodents.

    Science.gov (United States)

    Dere, Ekrem; Dere, Dorothea; de Souza Silva, Maria Angelica; Huston, Joseph P; Zlomuzica, Armin

    2017-03-19

    The impairment of mental time travel is a severe cognitive symptom in patients with brain lesions and a number of neuropsychiatric disorders. Whether animals are also able to mentally travel in time both forward and backward is still a matter of debate. In this regard, we have proposed a continuum of mental time travel abilities across different animal species, with humans being the species with the ability to perform most sophisticated forms of mental time travel. In this review and perspective article, we delineate a novel approach to understand the evolution, characteristics and function of human and animal mental time travel. Furthermore, we propose a novel approach to measure mental time travel in rodents in a comprehensive manner using a test battery composed of well-validated and easy applicable tests. Copyright © 2017. Published by Elsevier B.V.

  2. Computed tomography in patients with senile mental disorders

    International Nuclear Information System (INIS)

    Sugai, Yuuichi; Nakayama, Hirosi; Tatemichi, Nobuhiro

    1987-01-01

    Computed tomography (CT) was employed to follow up 28 patients with senile mental disorders (52 to 84 years of age) over a period of one to six and a half years after the first presentation. The first CT scans showed ventricular enlargement in many instances, which made it difficult to distinguish functional from degenerative diseases. The yearly rate of ventricular enlargement was, therefore, obtained on sequential CT scannings. The yearly rate of ventricular enlargement was high, which was associated with progression of the disease in the group with Alzheimer's disease. In the group with functional diseases, however, ventricular enlargement and progression were independent of each other. Both the yearly rate of ventricular enlargement and mental function significantly correlated with decreased adaptation of daily life. Periodical CT scanning and clinical observation over a certain period may offer useful information on the differential diagnosis and prognosis of senile mental disorders. (Namekawa, K.)

  3. Computational Psychiatry: towards a mathematically informed understanding of mental illness

    Science.gov (United States)

    Huys, Quentin J M; Roiser, Jonathan P

    2016-01-01

    Computational Psychiatry aims to describe the relationship between the brain's neurobiology, its environment and mental symptoms in computational terms. In so doing, it may improve psychiatric classification and the diagnosis and treatment of mental illness. It can unite many levels of description in a mechanistic and rigorous fashion, while avoiding biological reductionism and artificial categorisation. We describe how computational models of cognition can infer the current state of the environment and weigh up future actions, and how these models provide new perspectives on two example disorders, depression and schizophrenia. Reinforcement learning describes how the brain can choose and value courses of actions according to their long-term future value. Some depressive symptoms may result from aberrant valuations, which could arise from prior beliefs about the loss of agency (‘helplessness’), or from an inability to inhibit the mental exploration of aversive events. Predictive coding explains how the brain might perform Bayesian inference about the state of its environment by combining sensory data with prior beliefs, each weighted according to their certainty (or precision). Several cortical abnormalities in schizophrenia might reduce precision at higher levels of the inferential hierarchy, biasing inference towards sensory data and away from prior beliefs. We discuss whether striatal hyperdopaminergia might have an adaptive function in this context, and also how reinforcement learning and incentive salience models may shed light on the disorder. Finally, we review some of Computational Psychiatry's applications to neurological disorders, such as Parkinson's disease, and some pitfalls to avoid when applying its methods. PMID:26157034

  4. Hybrid computing using a neural network with dynamic external memory.

    Science.gov (United States)

    Graves, Alex; Wayne, Greg; Reynolds, Malcolm; Harley, Tim; Danihelka, Ivo; Grabska-Barwińska, Agnieszka; Colmenarejo, Sergio Gómez; Grefenstette, Edward; Ramalho, Tiago; Agapiou, John; Badia, Adrià Puigdomènech; Hermann, Karl Moritz; Zwols, Yori; Ostrovski, Georg; Cain, Adam; King, Helen; Summerfield, Christopher; Blunsom, Phil; Kavukcuoglu, Koray; Hassabis, Demis

    2016-10-27

    Artificial neural networks are remarkably adept at sensory processing, sequence learning and reinforcement learning, but are limited in their ability to represent variables and data structures and to store data over long timescales, owing to the lack of an external memory. Here we introduce a machine learning model called a differentiable neural computer (DNC), which consists of a neural network that can read from and write to an external memory matrix, analogous to the random-access memory in a conventional computer. Like a conventional computer, it can use its memory to represent and manipulate complex data structures, but, like a neural network, it can learn to do so from data. When trained with supervised learning, we demonstrate that a DNC can successfully answer synthetic questions designed to emulate reasoning and inference problems in natural language. We show that it can learn tasks such as finding the shortest path between specified points and inferring the missing links in randomly generated graphs, and then generalize these tasks to specific graphs such as transport networks and family trees. When trained with reinforcement learning, a DNC can complete a moving blocks puzzle in which changing goals are specified by sequences of symbols. Taken together, our results demonstrate that DNCs have the capacity to solve complex, structured tasks that are inaccessible to neural networks without external read-write memory.

  5. Mental workload during brain-computer interface training.

    Science.gov (United States)

    Felton, Elizabeth A; Williams, Justin C; Vanderheiden, Gregg C; Radwin, Robert G

    2012-01-01

    It is not well understood how people perceive the difficulty of performing brain-computer interface (BCI) tasks, which specific aspects of mental workload contribute the most, and whether there is a difference in perceived workload between participants who are able-bodied and disabled. This study evaluated mental workload using the NASA Task Load Index (TLX), a multi-dimensional rating procedure with six subscales: Mental Demands, Physical Demands, Temporal Demands, Performance, Effort, and Frustration. Able-bodied and motor disabled participants completed the survey after performing EEG-based BCI Fitts' law target acquisition and phrase spelling tasks. The NASA-TLX scores were similar for able-bodied and disabled participants. For example, overall workload scores (range 0-100) for 1D horizontal tasks were 48.5 (SD = 17.7) and 46.6 (SD 10.3), respectively. The TLX can be used to inform the design of BCIs that will have greater usability by evaluating subjective workload between BCI tasks, participant groups, and control modalities. Mental workload of brain-computer interfaces (BCI) can be evaluated with the NASA Task Load Index (TLX). The TLX is an effective tool for comparing subjective workload between BCI tasks, participant groups (able-bodied and disabled), and control modalities. The data can inform the design of BCIs that will have greater usability.

  6. Computing with memory for energy-efficient robust systems

    CERN Document Server

    Paul, Somnath

    2013-01-01

    This book analyzes energy and reliability as major challenges faced by designers of computing frameworks in the nanometer technology regime.  The authors describe the existing solutions to address these challenges and then reveal a new reconfigurable computing platform, which leverages high-density nanoscale memory for both data storage and computation to maximize the energy-efficiency and reliability. The energy and reliability benefits of this new paradigm are illustrated and the design challenges are discussed. Various hardware and software aspects of this exciting computing paradigm are de

  7. Toward Impactful Collaborations on Computing and Mental Health.

    Science.gov (United States)

    Calvo, Rafael Alejandro; Dinakar, Karthik; Picard, Rosalind; Christensen, Helen; Torous, John

    2018-02-09

    We describe an initiative to bring mental health researchers, computer scientists, human-computer interaction researchers, and other communities together to address the challenges of the global mental ill health epidemic. Two face-to-face events and one special issue of the Journal of Medical Internet Research were organized. The works presented in these events and publication reflect key state-of-the-art research in this interdisciplinary collaboration. We summarize the special issue articles and contextualize them to present a picture of the most recent research. In addition, we describe a series of collaborative activities held during the second symposium and where the community identified 5 challenges and their possible solutions. ©Rafael Alejandro Calvo, Karthik Dinakar, Rosalind Picard, Helen Christensen, John Torous. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 09.02.2018.

  8. Multiple-User, Multitasking, Virtual-Memory Computer System

    Science.gov (United States)

    Generazio, Edward R.; Roth, Don J.; Stang, David B.

    1993-01-01

    Computer system designed and programmed to serve multiple users in research laboratory. Provides for computer control and monitoring of laboratory instruments, acquisition and anlaysis of data from those instruments, and interaction with users via remote terminals. System provides fast access to shared central processing units and associated large (from megabytes to gigabytes) memories. Underlying concept of system also applicable to monitoring and control of industrial processes.

  9. Graphical Visualization on Computational Simulation Using Shared Memory

    International Nuclear Information System (INIS)

    Lima, A B; Correa, Eberth

    2014-01-01

    The Shared Memory technique is a powerful tool for parallelizing computer codes. In particular it can be used to visualize the results ''on the fly'' without stop running the simulation. In this presentation we discuss and show how to use the technique conjugated with a visualization code using openGL

  10. Persistent Memory in Single Node Delay-Coupled Reservoir Computing.

    Directory of Open Access Journals (Sweden)

    André David Kovac

    Full Text Available Delays are ubiquitous in biological systems, ranging from genetic regulatory networks and synaptic conductances, to predator/pray population interactions. The evidence is mounting, not only to the presence of delays as physical constraints in signal propagation speed, but also to their functional role in providing dynamical diversity to the systems that comprise them. The latter observation in biological systems inspired the recent development of a computational architecture that harnesses this dynamical diversity, by delay-coupling a single nonlinear element to itself. This architecture is a particular realization of Reservoir Computing, where stimuli are injected into the system in time rather than in space as is the case with classical recurrent neural network realizations. This architecture also exhibits an internal memory which fades in time, an important prerequisite to the functioning of any reservoir computing device. However, fading memory is also a limitation to any computation that requires persistent storage. In order to overcome this limitation, the current work introduces an extended version to the single node Delay-Coupled Reservoir, that is based on trained linear feedback. We show by numerical simulations that adding task-specific linear feedback to the single node Delay-Coupled Reservoir extends the class of solvable tasks to those that require nonfading memory. We demonstrate, through several case studies, the ability of the extended system to carry out complex nonlinear computations that depend on past information, whereas the computational power of the system with fading memory alone quickly deteriorates. Our findings provide the theoretical basis for future physical realizations of a biologically-inspired ultrafast computing device with extended functionality.

  11. Persistent Memory in Single Node Delay-Coupled Reservoir Computing.

    Science.gov (United States)

    Kovac, André David; Koall, Maximilian; Pipa, Gordon; Toutounji, Hazem

    2016-01-01

    Delays are ubiquitous in biological systems, ranging from genetic regulatory networks and synaptic conductances, to predator/pray population interactions. The evidence is mounting, not only to the presence of delays as physical constraints in signal propagation speed, but also to their functional role in providing dynamical diversity to the systems that comprise them. The latter observation in biological systems inspired the recent development of a computational architecture that harnesses this dynamical diversity, by delay-coupling a single nonlinear element to itself. This architecture is a particular realization of Reservoir Computing, where stimuli are injected into the system in time rather than in space as is the case with classical recurrent neural network realizations. This architecture also exhibits an internal memory which fades in time, an important prerequisite to the functioning of any reservoir computing device. However, fading memory is also a limitation to any computation that requires persistent storage. In order to overcome this limitation, the current work introduces an extended version to the single node Delay-Coupled Reservoir, that is based on trained linear feedback. We show by numerical simulations that adding task-specific linear feedback to the single node Delay-Coupled Reservoir extends the class of solvable tasks to those that require nonfading memory. We demonstrate, through several case studies, the ability of the extended system to carry out complex nonlinear computations that depend on past information, whereas the computational power of the system with fading memory alone quickly deteriorates. Our findings provide the theoretical basis for future physical realizations of a biologically-inspired ultrafast computing device with extended functionality.

  12. [Prospective memory - concepts, methods of assessment, neuroanatomical bases and its deficits in mental disorders].

    Science.gov (United States)

    Wiłkość, Monika; Izdebski, Paweł; Zajac-Lamparska, Ludmiła

    2013-01-01

    In the last two decades of the last century there has been a shift in the studies on memory. In psychology of memory the criticism of the laboratory approach resulted in development of the ecological approach. One of the effects of this change was to initiate researches on memory that includes plans for the future, which has resulted in the distinction of the concept of prospective memory. Prospective memory is used in many aspects of everyday life. It deals with remembering intentions and plans, it is connected with remembering about specific task or activity in the future. There are three types of PM: event-based prospective memory, time-based prospective memory and activity-based prospective memory. Current research in this field have already established its own paradigm and tools measuring PM and there is still increasing scientific interest in this issue. Prospective memory assessment may be carried out in various ways. Among them, the most frequently used are: a) questionnaires, b) psychological tests, c) experimental procedures. Within the latter, the additional distinction can be introduced for: the experiments conducted under natural conditions and the laboratory procedures. In Polish literature, there are only a few articles on PM. The aim of this work is to review studies on assessment methods of PM. Its neuroanatomical bases and its functioning in different mental disorders are analyzed. The work is aimed to focus clinicians attention on prospective memory as an area which is important for complex diagnosis of cognitive processes.

  13. Social influence and mental routes to the production of authentic false memories and inauthentic false memories.

    Science.gov (United States)

    Wagner, Michael F; Skowronski, John J

    2017-05-01

    Two studies assessed the extent to which people incorporated false facts provided by bogus others into their own recognition memory reports, and how these false memory reports were affected by: (a) truth of the information in others' summaries supporting the false facts, (b) motivation to process stories and summaries, (c) source credibility, and (d) ease of remembering original facts. False memory report frequency increased when false facts in a summary were supported by true information and varied inversely with the ease with which original facts could be remembered. Results from a measure probing participants' memory perceptions suggest that some false memories are authentic: People sometimes lack awareness of both the incorporation of false facts into their memory reports and where the false facts came from. However, many false memories are inauthentic: Despite reporting a false memory, people sometimes retain knowledge of the original stimulus and/or the origin of false facts. Copyright © 2017. Published by Elsevier Inc.

  14. Optical computing, optical memory, and SBIRs at Foster-Miller

    Science.gov (United States)

    Domash, Lawrence H.

    1994-03-01

    A desktop design and manufacturing system for binary diffractive elements, MacBEEP, was developed with the optical researcher in mind. Optical processing systems for specialized tasks such as cellular automation computation and fractal measurement were constructed. A new family of switchable holograms has enabled several applications for control of laser beams in optical memories. New spatial light modulators and optical logic elements have been demonstrated based on a more manufacturable semiconductor technology. Novel synthetic and polymeric nonlinear materials for optical storage are under development in an integrated memory architecture. SBIR programs enable creative contributions from smaller companies, both product oriented and technology oriented, and support advances that might not otherwise be developed.

  15. Prospective memory, level of disability, and return to work in severe mental illness.

    Science.gov (United States)

    Burton, Cynthia Z; Vella, Lea; Twamley, Elizabeth W

    2018-02-25

    Prospective memory (the ability to remember to do things) has clear implications for everyday functioning, including employment, in people with severe mental illnesses (SMI). This study aimed to evaluate prospective memory performance and its relationship to real-world functional variables in an employment-seeking sample of people with SMI (Clinical Trial registration number NCT00895258). 153 individuals with DSM-IV diagnosis of depression (n = 58), bipolar disorder (n = 37), or schizophrenia (n = 58) who were receiving outpatient psychiatric care at a university clinic enrolled in a trial of supported employment and completed a baseline assessment. Prospective memory was measured with the Memory for Intentions Test (MIST); real-world functional status included work history variables, clinical history variables, baseline functional capacity (UCSD Performance-based Skills Assessment-Brief), and work outcomes (weeks worked and wages earned during two years of supported employment). Participants with schizophrenia performed worse on the MIST than did those with affective disorders. Independent of diagnosis, education, and estimated intellectual functioning, prospective memory significantly predicted variance in measures of disability and illness burden (disability benefits, hospitalization history, current functional capacity), and work outcomes over two years of supported employment (weeks worked). Worse prospective memory appears to be associated with greater illness burden and functional disability in SMI. Mental health clinicians and employment specialists may counsel clients to use compensatory prospective memory strategies to improve work performance and decrease functional disability associated with SMI.

  16. The Power of Iconic Memory: Iconoclasm as a Mental Marker

    Directory of Open Access Journals (Sweden)

    Koenraad Jonckheere

    2016-03-01

    Full Text Available Iconoclasm has a particular effect in that it creates an image that is even more powerful than the image it has destroyed. While many physical images might have disappeared due to the iconoclasm, the mental image of all who witnessed this dramatic moment in history was indelible. This article argues that artists made conscious use of the emotional and cognitive power of such mental images to give their work meaning. De kracht van iconisch geheugen. Iconoclasme als een mentale markeringIconoclasme heeft het bijzondere effect dat het een beeld creëert dat nog sterker is dan het beeld dat het vernielt. De vele fysieke beelden mogen dan al verdwenen zijn door de Beeldenstorm, het mentale beeld werd een onuitwisbare herinnering aan een ingrijpend moment in de geschiedenis voor iedereen die er getuige van was. In dit artikel wordt beargumenteerd dat kunstenaars bewust gebruik maakten van de emotionele en cognitieve kracht van dit mentale beeld om hun werk betekenis te geven.

  17. Body image, visual working memory and visual mental imagery

    Directory of Open Access Journals (Sweden)

    Stephen Darling

    2015-02-01

    Full Text Available Body dissatisfaction (BD is a highly prevalent feature amongst females in society, with the majority of individuals regarding themselves to be overweight compared to their personal ideal, and very few self-describing as underweight. To date, explanations of this dramatic pattern have centred on extrinsic social and media factors, or intrinsic factors connected to individuals’ knowledge and belief structures regarding eating and body shape, with little research examining links between BD and basic cognitive mechanisms. This paper reports a correlational study in which visual and executive cognitive processes that could potentially impact on BD were assessed. Visual memory span and self-rated visual imagery were found to be predictive of BD, alongside a measure of inhibition derived from the Stroop task. In contrast, spatial memory and global precedence were not related to BD. Results are interpreted with reference to the influential multi-component model of working memory.

  18. Short-Term Memory for Pictures and Words by Mentally Retarded and Nonretarded Persons.

    Science.gov (United States)

    Ellis, Norman R.; Wooldridge, Peter W.

    1985-01-01

    Twelve mentally retarded and 12 nonretarded adults were compared in a Brown-Peterson short-term memory task for the retention of words and pictures over intervals up to 30 seconds. The retarded subjects forgot more rapidly over the initial 10 seconds. They also retained pictures better than they did words. (Author/DB)

  19. Parietal and early visual cortices encode working memory content across mental transformations.

    Science.gov (United States)

    Christophel, Thomas B; Cichy, Radoslaw M; Hebart, Martin N; Haynes, John-Dylan

    2015-02-01

    Active and flexible manipulations of memory contents "in the mind's eye" are believed to occur in a dedicated neural workspace, frequently referred to as visual working memory. Such a neural workspace should have two important properties: The ability to store sensory information across delay periods and the ability to flexibly transform sensory information. Here we used a combination of functional MRI and multivariate decoding to indentify such neural representations. Subjects were required to memorize a complex artificial pattern for an extended delay, then rotate the mental image as instructed by a cue and memorize this transformed pattern. We found that patterns of brain activity already in early visual areas and posterior parietal cortex encode not only the initially remembered image, but also the transformed contents after mental rotation. Our results thus suggest that the flexible and general neural workspace supporting visual working memory can be realized within posterior brain regions. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Mental schemas hamper memory storage of goal-irrelevant information

    NARCIS (Netherlands)

    Sweegers, C.C.G.; Coleman, G.A.; van Poppel, E.A.M.; Cox, R.; Talamini, L.M.

    2015-01-01

    Mental schemas exert top-down control on information processing, for instance by facilitating the storage of schema-related information. However, given capacity-limits and competition in neural network processing, schemas may additionally exert their effects by suppressing information with low

  1. Iconic Memory Deficit of Mildly Mentally Retarded Individuals.

    Science.gov (United States)

    Hornstein, Henry A.; Mosley, James L.

    1987-01-01

    Ten mildly retarded young adult males and nonretarded subjects matched for chronological age or mental age were required to recognize both verbal and nonverbal stimuli presented tachistoscopically. Results of a backward visual masking paradigm varying stimulus onset asynchrony (SOA) indicated the retarded subjects performed poorer at the longest…

  2. emMAW: computing minimal absent words in external memory.

    Science.gov (United States)

    Héliou, Alice; Pissis, Solon P; Puglisi, Simon J

    2017-09-01

    The biological significance of minimal absent words has been investigated in genomes of organisms from all domains of life. For instance, three minimal absent words of the human genome were found in Ebola virus genomes. There exists an O(n) -time and O(n) -space algorithm for computing all minimal absent words of a sequence of length n on a fixed-sized alphabet based on suffix arrays. A standard implementation of this algorithm, when applied to a large sequence of length n , requires more than 20 n  bytes of RAM. Such memory requirements are a significant hurdle to the computation of minimal absent words in large datasets. We present emMAW, the first external-memory algorithm for computing minimal absent words. A free open-source implementation of our algorithm is made available. This allows for computation of minimal absent words on far bigger data sets than was previously possible. Our implementation requires less than 3 h on a standard workstation to process the full human genome when as little as 1 GB of RAM is made available. We stress that our implementation, despite making use of external memory, is fast; indeed, even on relatively smaller datasets when enough RAM is available to hold all necessary data structures, it is less than two times slower than state-of-the-art internal-memory implementations. https://github.com/solonas13/maw (free software under the terms of the GNU GPL). alice.heliou@lix.polytechnique.fr or solon.pissis@kcl.ac.uk. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  3. Visual memory and visual mental imagery recruit common control and sensory regions of the brain.

    Science.gov (United States)

    Slotnick, Scott D; Thompson, William L; Kosslyn, Stephen M

    2012-01-01

    Separate lines of research have shown that visual memory and visual mental imagery are mediated by frontal-parietal control regions and can rely on occipital-temporal sensory regions of the brain. We used fMRI to assess the degree to which visual memory and visual mental imagery rely on the same neural substrates. During the familiarization/study phase, participants studied drawings of objects. During the test phase, words corresponding to old and new objects were presented. In the memory test, participants responded "remember," "know," or "new." In the imagery test, participants responded "high vividness," "moderate vividness," or "low vividness." Visual memory (old-remember) and visual imagery (old-high vividness) were commonly associated with activity in frontal-parietal control regions and occipital-temporal sensory regions. In addition, visual memory produced greater activity than visual imagery in parietal and occipital-temporal regions. The present results suggest that visual memory and visual imagery rely on highly similar--but not identical--cognitive processes.

  4. A compositional reservoir simulator on distributed memory parallel computers

    International Nuclear Information System (INIS)

    Rame, M.; Delshad, M.

    1995-01-01

    This paper presents the application of distributed memory parallel computes to field scale reservoir simulations using a parallel version of UTCHEM, The University of Texas Chemical Flooding Simulator. The model is a general purpose highly vectorized chemical compositional simulator that can simulate a wide range of displacement processes at both field and laboratory scales. The original simulator was modified to run on both distributed memory parallel machines (Intel iPSC/960 and Delta, Connection Machine 5, Kendall Square 1 and 2, and CRAY T3D) and a cluster of workstations. A domain decomposition approach has been taken towards parallelization of the code. A portion of the discrete reservoir model is assigned to each processor by a set-up routine that attempts a data layout as even as possible from the load-balance standpoint. Each of these subdomains is extended so that data can be shared between adjacent processors for stencil computation. The added routines that make parallel execution possible are written in a modular fashion that makes the porting to new parallel platforms straight forward. Results of the distributed memory computing performance of Parallel simulator are presented for field scale applications such as tracer flood and polymer flood. A comparison of the wall-clock times for same problems on a vector supercomputer is also presented

  5. Injecting Artificial Memory Errors Into a Running Computer Program

    Science.gov (United States)

    Bornstein, Benjamin J.; Granat, Robert A.; Wagstaff, Kiri L.

    2008-01-01

    Single-event upsets (SEUs) or bitflips are computer memory errors caused by radiation. BITFLIPS (Basic Instrumentation Tool for Fault Localized Injection of Probabilistic SEUs) is a computer program that deliberately injects SEUs into another computer program, while the latter is running, for the purpose of evaluating the fault tolerance of that program. BITFLIPS was written as a plug-in extension of the open-source Valgrind debugging and profiling software. BITFLIPS can inject SEUs into any program that can be run on the Linux operating system, without needing to modify the program s source code. Further, if access to the original program source code is available, BITFLIPS offers fine-grained control over exactly when and which areas of memory (as specified via program variables) will be subjected to SEUs. The rate of injection of SEUs is controlled by specifying either a fault probability or a fault rate based on memory size and radiation exposure time, in units of SEUs per byte per second. BITFLIPS can also log each SEU that it injects and, if program source code is available, report the magnitude of effect of the SEU on a floating-point value or other program variable.

  6. MENTAL SHIFT TOWARDS SYSTEMS THINKING SKILLS IN COMPUTER SCIENCE

    Directory of Open Access Journals (Sweden)

    MILDEOVÁ, Stanislava

    2012-03-01

    Full Text Available When seeking solutions to current problems in the field of computer science – and other fields – we encounter situations where traditional approaches no longer bring the desired results. Our cognitive skills also limit the implementation of reliable mental simulation within the basic set of relations. The world around us is becoming more complex and mutually interdependent, and this is reflected in the demands on computer support. Thus, in today’s education and science in the field of computer science and all other disciplines and areas of life need to address the issue of the paradigm shift, which is generally accepted by experts. The goal of the paper is to present the systems thinking that facilitates and extends the understanding of the world through relations and linkages. Moreover, the paper introduces the essence of systems thinking and the possibilities to achieve mental a shift toward systems thinking skills. At the same time, the link between systems thinking and functional literacy is presented. We adopted the “Bathtub Test” from the variety of systems thinking tests that allow people to assess the understanding of basic systemic concepts, in order to assess the level of systems thinking. University students (potential information managers were the examined subjects of the examination of systems thinking that was conducted over a longer time period and whose aim was to determine the status of systems thinking. . The paper demonstrates that some pedagogical concepts and activities, in our case the subject of System Dynamics that leads to the appropriate integration of systems thinking in education. There is some evidence that basic knowledge of system dynamics and systems thinking principles will affect students, and their thinking will contribute to an improved approach to solving problems of computer science both in theory and practice.

  7. Interdisciplinary Approach to the Mental Lexicon: Neural Network and Text Extraction From Long-term Memory

    Directory of Open Access Journals (Sweden)

    Vardan G. Arutyunyan

    2013-01-01

    Full Text Available The paper touches upon the principles of mental lexicon organization in the light of recent research in psycho- and neurolinguistics. As a focal point of discussion two main approaches to mental lexicon functioning are considered: modular or dual-system approach, developed within generativism and opposite single-system approach, representatives of which are the connectionists and supporters of network models. The paper is an endeavor towards advocating the viewpoint that mental lexicon is complex psychological organization based upon specific composition of neural network. In this regard, the paper further elaborates on the matter of storing text in human mental space and introduces a model of text extraction from long-term memory. Based upon data available, the author develops a methodology of modeling structures of knowledge representation in the systems of artificial intelligence.

  8. Reprogrammable logic in memristive crossbar for in-memory computing

    Science.gov (United States)

    Cheng, Long; Zhang, Mei-Yun; Li, Yi; Zhou, Ya-Xiong; Wang, Zhuo-Rui; Hu, Si-Yu; Long, Shi-Bing; Liu, Ming; Miao, Xiang-Shui

    2017-12-01

    Memristive stateful logic has emerged as a promising next-generation in-memory computing paradigm to address escalating computing-performance pressures in traditional von Neumann architecture. Here, we present a nonvolatile reprogrammable logic method that can process data between different rows and columns in a memristive crossbar array based on material implication (IMP) logic. Arbitrary Boolean logic can be executed with a reprogrammable cell containing four memristors in a crossbar array. In the fabricated Ti/HfO2/W memristive array, some fundamental functions, such as universal NAND logic and data transfer, were experimentally implemented. Moreover, using eight memristors in a 2  ×  4 array, a one-bit full adder was theoretically designed and verified by simulation to exhibit the feasibility of our method to accomplish complex computing tasks. In addition, some critical logic-related performances were further discussed, such as the flexibility of data processing, cascading problem and bit error rate. Such a method could be a step forward in developing IMP-based memristive nonvolatile logic for large-scale in-memory computing architecture.

  9. Strategy Ranges: Describing Change in Prospective Elementary Teachers' Approaches to Mental Computation of Sums and Differences

    Science.gov (United States)

    Whitacre, Ian

    2015-01-01

    This study investigated the sets of mental computation strategies used by prospective elementary teachers to compute sums and differences of whole numbers. In the context of an intervention designed to improve the number sense of prospective elementary teachers, participants were interviewed pre/post, and their mental computation strategies were…

  10. Avalanches and generalized memory associativity in a network model for conscious and unconscious mental functioning

    Science.gov (United States)

    Siddiqui, Maheen; Wedemann, Roseli S.; Jensen, Henrik Jeldtoft

    2018-01-01

    We explore statistical characteristics of avalanches associated with the dynamics of a complex-network model, where two modules corresponding to sensorial and symbolic memories interact, representing unconscious and conscious mental processes. The model illustrates Freud's ideas regarding the neuroses and that consciousness is related with symbolic and linguistic memory activity in the brain. It incorporates the Stariolo-Tsallis generalization of the Boltzmann Machine in order to model memory retrieval and associativity. In the present work, we define and measure avalanche size distributions during memory retrieval, in order to gain insight regarding basic aspects of the functioning of these complex networks. The avalanche sizes defined for our model should be related to the time consumed and also to the size of the neuronal region which is activated, during memory retrieval. This allows the qualitative comparison of the behaviour of the distribution of cluster sizes, obtained during fMRI measurements of the propagation of signals in the brain, with the distribution of avalanche sizes obtained in our simulation experiments. This comparison corroborates the indication that the Nonextensive Statistical Mechanics formalism may indeed be more well suited to model the complex networks which constitute brain and mental structure.

  11. Towards Modeling False Memory With Computational Knowledge Bases.

    Science.gov (United States)

    Li, Justin; Kohanyi, Emma

    2017-01-01

    One challenge to creating realistic cognitive models of memory is the inability to account for the vast common-sense knowledge of human participants. Large computational knowledge bases such as WordNet and DBpedia may offer a solution to this problem but may pose other challenges. This paper explores some of these difficulties through a semantic network spreading activation model of the Deese-Roediger-McDermott false memory task. In three experiments, we show that these knowledge bases only capture a subset of human associations, while irrelevant information introduces noise and makes efficient modeling difficult. We conclude that the contents of these knowledge bases must be augmented and, more important, that the algorithms must be refined and optimized, before large knowledge bases can be widely used for cognitive modeling. Copyright © 2016 Cognitive Science Society, Inc.

  12. Translation Memory and Computer Assisted Translation Tool for Medieval Texts

    Directory of Open Access Journals (Sweden)

    Törcsvári Attila

    2013-05-01

    Full Text Available Translation memories (TMs, as part of Computer Assisted Translation (CAT tools, support translators reusing portions of formerly translated text. Fencing books are good candidates for using TMs due to the high number of repeated terms. Medieval texts suffer a number of drawbacks that make hard even “simple” rewording to the modern version of the same language. The analyzed difficulties are: lack of systematic spelling, unusual word orders and typos in the original. A hypothesis is made and verified that even simple modernization increases legibility and it is feasible, also it is worthwhile to apply translation memories due to the numerous and even extremely long repeated terms. Therefore, methods and algorithms are presented 1. for automated transcription of medieval texts (when a limited training set is available, and 2. collection of repeated patterns. The efficiency of the algorithms is analyzed for recall and precision.

  13. An Alternative Algorithm for Computing Watersheds on Shared Memory Parallel Computers

    NARCIS (Netherlands)

    Meijster, A.; Roerdink, J.B.T.M.

    1995-01-01

    In this paper a parallel implementation of a watershed algorithm is proposed. The algorithm can easily be implemented on shared memory parallel computers. The watershed transform is generally considered to be inherently sequential since the discrete watershed of an image is defined using recursion.

  14. A memory-array architecture for computer vision

    Energy Technology Data Exchange (ETDEWEB)

    Balsara, P.T.

    1989-01-01

    With the fast advances in the area of computer vision and robotics there is a growing need for machines that can understand images at a very high speed. A conventional von Neumann computer is not suited for this purpose because it takes a tremendous amount of time to solve most typical image processing problems. Exploiting the inherent parallelism present in various vision tasks can significantly reduce the processing time. Fortunately, parallelism is increasingly affordable as hardware gets cheaper. Thus it is now imperative to study computer vision in a parallel processing framework. The author should first design a computational structure which is well suited for a wide range of vision tasks and then develop parallel algorithms which can run efficiently on this structure. Recent advances in VLSI technology have led to several proposals for parallel architectures for computer vision. In this thesis he demonstrates that a memory array architecture with efficient local and global communication capabilities can be used for high speed execution of a wide range of computer vision tasks. This architecture, called the Access Constrained Memory Array Architecture (ACMAA), is efficient for VLSI implementation because of its modular structure, simple interconnect and limited global control. Several parallel vision algorithms have been designed for this architecture. The choice of vision problems demonstrates the versatility of ACMAA for a wide range of vision tasks. These algorithms were simulated on a high level ACMAA simulator running on the Intel iPSC/2 hypercube, a parallel architecture. The results of this simulation are compared with those of sequential algorithms running on a single hypercube node. Details of the ACMAA processor architecture are also presented.

  15. In between mental evolution and unconscious memory: Lamarckism, Darwinism, and professionalism in late Victorian Britain.

    Science.gov (United States)

    Turbil, Cristiano

    2017-09-01

    In 1884 Samuel Butler published a collection of essays entitled Remarks on George Romanes' Mental Evolution, where he attempted to show how Romanes' idea of mental evolution presented similarities with his theory of unconscious memory. By looking at Romanes' work through Butler's writing, this article will reevaluate some aspects of their works regarding the complex debate about memory, heredity, and instinct. This paper will explore the main differences and similarities between Romanes' science and Butler's writing on science both in terms of their ideas and contents. It will then look into their different professional relationships with Darwin and how this determined the professional and public reception of their theories. © 2017 Wiley Periodicals, Inc.

  16. Retrieval and organizational strategies in conceptual memory a computer model

    CERN Document Server

    Kolodner, Janet L

    2014-01-01

    'Someday we expect that computers will be able to keep us informed about the news. People have imagined being able to ask their home computers questions such as "What's going on in the world?"…'. Originally published in 1984, this book is a fascinating look at the world of memory and computers before the internet became the mainstream phenomenon it is today. It looks at the early development of a computer system that could keep us informed in a way that we now take for granted. Presenting a theory of remembering, based on human information processing, it begins to address many of the hard problems implicated in the quest to make computers remember. The book had two purposes in presenting this theory of remembering. First, to be used in implementing intelligent computer systems, including fact retrieval systems and intelligent systems in general. Any intelligent program needs to use and store and use a great deal of knowledge. The strategies and structures in the book were designed to be used for that purpos...

  17. Robust dynamical decoupling for quantum computing and quantum memory.

    Science.gov (United States)

    Souza, Alexandre M; Alvarez, Gonzalo A; Suter, Dieter

    2011-06-17

    Dynamical decoupling (DD) is a popular technique for protecting qubits from the environment. However, unless special care is taken, experimental errors in the control pulses used in this technique can destroy the quantum information instead of preserving it. Here, we investigate techniques for making DD sequences robust against different types of experimental errors while retaining good decoupling efficiency in a fluctuating environment. We present experimental data from solid-state nuclear spin qubits and introduce a new DD sequence that is suitable for quantum computing and quantum memory.

  18. Computational performance of a smoothed particle hydrodynamics simulation for shared-memory parallel computing

    Science.gov (United States)

    Nishiura, Daisuke; Furuichi, Mikito; Sakaguchi, Hide

    2015-09-01

    The computational performance of a smoothed particle hydrodynamics (SPH) simulation is investigated for three types of current shared-memory parallel computer devices: many integrated core (MIC) processors, graphics processing units (GPUs), and multi-core CPUs. We are especially interested in efficient shared-memory allocation methods for each chipset, because the efficient data access patterns differ between compute unified device architecture (CUDA) programming for GPUs and OpenMP programming for MIC processors and multi-core CPUs. We first introduce several parallel implementation techniques for the SPH code, and then examine these on our target computer architectures to determine the most effective algorithms for each processor unit. In addition, we evaluate the effective computing performance and power efficiency of the SPH simulation on each architecture, as these are critical metrics for overall performance in a multi-device environment. In our benchmark test, the GPU is found to produce the best arithmetic performance as a standalone device unit, and gives the most efficient power consumption. The multi-core CPU obtains the most effective computing performance. The computational speed of the MIC processor on Xeon Phi approached that of two Xeon CPUs. This indicates that using MICs is an attractive choice for existing SPH codes on multi-core CPUs parallelized by OpenMP, as it gains computational acceleration without the need for significant changes to the source code.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vineyard, Craig Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Verzi, Stephen Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    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 utilize memory.

  20. Mental health, citizenship, and the memory of World War II in the Netherlands (1945-85).

    Science.gov (United States)

    Oosterhuis, Harry

    2014-03-01

    After World War II, Dutch psychiatrists and other mental health care professionals articulated ideals of democratic citizenship. Framed in terms of self-development, citizenship took on a broad meaning, not just in terms of political rights and obligations, but also in the context of material, social, psychological and moral conditions that individuals should meet in order to develop themselves and be able to act according to those rights and obligations in a responsible way. In the post-war period of reconstruction (1945-65), as well as between 1965 and 1985, the link between mental health and ideals of citizenship was coloured by the public memory of World War II and the German occupation, albeit in completely different, even opposite ways. The memory of the war, and especially the public consideration of its victims, changed drastically in the mid-1960s, and the mental health sector played a crucial role in bringing this change about. The widespread attention to the mental effects of the war that surfaced in the late 1960s after a period of 20 years of public silence should be seen against the backdrop of the combination of democratization and the emancipation of emotions.

  1. Semantic and Phonological Loop Effects on Verbal Working Memory in Middle-Age Adults with Mental Retardation

    Science.gov (United States)

    Kittler, Phyllis; Krinsky-McHale, Sharon J.; Devenny, Darlynne A.

    2004-01-01

    Semantic and phonological loop effects on verbal working memory were examined among middle-age adults with Down syndrome and those with unspecified mental retardation in the context of Baddeley's working memory model. Recall was poorer for phonologically similar, semantically similar, and long words compared to recall of dissimilar short words.…

  2. Rapid mental computation system as a tool for algorithmic thinking of elementary school students development

    OpenAIRE

    Ziatdinov, Rushan; Musa, Sajid

    2013-01-01

    In this paper, we describe the possibilities of using a rapid mental computation system in elementary education. The system consists of a number of readily memorized operations that allow one to perform arithmetic computations very quickly. These operations are actually simple algorithms which can develop or improve the algorithmic thinking of pupils. Using a rapid mental computation system allows forming the basis for the study of computer science in secondary school.

  3. A Developmental Scale of Mental Computation with Part-Whole Numbers

    Science.gov (United States)

    Callingham, Rosemary; Watson, Jane

    2004-01-01

    In this article, data from a study of the mental computation competence of students in grades 3 to 10 are presented. Students responded to mental computation items, presented orally, that included operations applied to fractions, decimals and percents. The data were analysed using Rasch modelling techniques, and a six-level hierarchy of part-whole…

  4. Mental Computation or Standard Algorithm? Children's Strategy Choices on Multi-Digit Subtractions

    Science.gov (United States)

    Torbeyns, Joke; Verschaffel, Lieven

    2016-01-01

    This study analyzed children's use of mental computation strategies and the standard algorithm on multi-digit subtractions. Fifty-eight Flemish 4th graders of varying mathematical achievement level were individually offered subtractions that either stimulated the use of mental computation strategies or the standard algorithm in one choice and two…

  5. Perspective: Memcomputing: Leveraging memory and physics to compute efficiently

    Science.gov (United States)

    Di Ventra, Massimiliano; Traversa, Fabio L.

    2018-05-01

    It is well known that physical phenomena may be of great help in computing some difficult problems efficiently. A typical example is prime factorization that may be solved in polynomial time by exploiting quantum entanglement on a quantum computer. There are, however, other types of (non-quantum) physical properties that one may leverage to compute efficiently a wide range of hard problems. In this perspective, we discuss how to employ one such property, memory (time non-locality), in a novel physics-based approach to computation: Memcomputing. In particular, we focus on digital memcomputing machines (DMMs) that are scalable. DMMs can be realized with non-linear dynamical systems with memory. The latter property allows the realization of a new type of Boolean logic, one that is self-organizing. Self-organizing logic gates are "terminal-agnostic," namely, they do not distinguish between the input and output terminals. When appropriately assembled to represent a given combinatorial/optimization problem, the corresponding self-organizing circuit converges to the equilibrium points that express the solutions of the problem at hand. In doing so, DMMs take advantage of the long-range order that develops during the transient dynamics. This collective dynamical behavior, reminiscent of a phase transition, or even the "edge of chaos," is mediated by families of classical trajectories (instantons) that connect critical points of increasing stability in the system's phase space. The topological character of the solution search renders DMMs robust against noise and structural disorder. Since DMMs are non-quantum systems described by ordinary differential equations, not only can they be built in hardware with the available technology, they can also be simulated efficiently on modern classical computers. As an example, we will show the polynomial-time solution of the subset-sum problem for the worst cases, and point to other types of hard problems where simulations of DMMs

  6. Mental Imagery and Posttraumatic Stress Disorder: a neuroimaging and experimental psychopathology approach to intrusive memories of trauma

    Directory of Open Access Journals (Sweden)

    Ian A Clark

    2015-07-01

    Full Text Available This hypothesis and theory paper presents a pragmatic framework to help bridge the clinical presentation and neuroscience of intrusive memories following psychological trauma. Intrusive memories are a hallmark symptom of Posttraumatic Stress Disorder. However, key questions, including those involving aetiology remain. In particular, we know little about the brain mechanisms involved in why only some moments of the trauma return as intrusive memories while others do not. We first present an overview of the patient experience of intrusive memories and the neuroimaging studies that have investigated intrusive memories in PTSD patients. Next, one mechanism of how to model intrusive memories in the laboratory, the trauma film paradigm, is examined. In particular, we focus on studies combining the trauma film paradigm with neuroimaging. Stemming from the clinical presentation and our current understanding of the processes involved in intrusive memories, we propose a framework in which an intrusive memory comprises five component parts; autobiographical (trauma memory, involuntary recall, negative emotions, attention hijacking and mental imagery. Each component part is considered in turn, both behaviourally and from a brain imaging perspective. A mapping of these five components onto our understanding of the brain is described. Unanswered questions that exist in our understanding of intrusive memories are considered using the proposed framework. Overall, we suggest that mental imagery is key to bridging the experience, memory and intrusive recollection of the traumatic event. Further, we suggest that by considering the brain mechanisms involved in the component parts of an intrusive memory, in particular mental imagery, we may be able to aid the development of a firmer bridge between patients’ experiences of intrusive memories and the clinical neuroscience behind them.

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

    Science.gov (United States)

    Sato, Naoyuki; Yamaguchi, Yoko

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

  8. Computer Use and Its Effect on the Memory Process in Young and Adults

    Science.gov (United States)

    Alliprandini, Paula Mariza Zedu; Straub, Sandra Luzia Wrobel; Brugnera, Elisangela; de Oliveira, Tânia Pitombo; Souza, Isabela Augusta Andrade

    2013-01-01

    This work investigates the effect of computer use in the memory process in young and adults under the Perceptual and Memory experimental conditions. The memory condition involved the phases acquisition of information and recovery, on time intervals (2 min, 24 hours and 1 week) on situations of pre and post-test (before and after the participants…

  9. High-performers use the phonological loop less to process mental arithmetic during working memory tasks.

    Science.gov (United States)

    Otsuka, Yuki; Osaka, Naoyuki

    2015-01-01

    This study investigated the effects of three working memory components-the central executive, phonological loop, and visuospatial sketchpad-on performance differences in complex mental arithmetic between individuals. Using the dual-task method, we examined how performance during two-digit addition was affected by load on the central executive (random tapping condition), phonological loop (articulatory suppression condition), and visuospatial sketchpad (spatial tapping condition) compared to that under no load (control condition) in high- and low-performers of complex mental arithmetic in Experiment 1. Low-performers showed an increase in errors under the random tapping and articulatory suppression conditions, whereas high-performers showed an increase of errors only under the random tapping condition. In Experiment 2, we conducted similar experiments on only the high-performers but used a shorter presentation time of each number. We found the same pattern for performing complex mental arithmetic as seen in Experiment 1. These results indicate that high-performers might reduce their dependence on the phonological loop, because the central executive enables them to choose a strategy in which they use less working memory capacity.

  10. Energy-aware memory management for embedded multimedia systems a computer-aided design approach

    CERN Document Server

    Balasa, Florin

    2011-01-01

    Energy-Aware Memory Management for Embedded Multimedia Systems: A Computer-Aided Design Approach presents recent computer-aided design (CAD) ideas that address memory management tasks, particularly the optimization of energy consumption in the memory subsystem. It explains how to efficiently implement CAD solutions, including theoretical methods and novel algorithms. The book covers various energy-aware design techniques, including data-dependence analysis techniques, memory size estimation methods, extensions of mapping approaches, and memory banking approaches. It shows how these techniques

  11. Providing for organizational memory in computer supported meetings

    OpenAIRE

    Schwabe, Gerhard

    1994-01-01

    Meeting memory features are poorly integrated into current group support systems (GSS). In this article, I discuss how to introduce meeting memory functionality into a GSS. The article first introduces the benefits of effective meetings and organizational memory to an organization. Then, the following challenges to design are discussed: How to store semantically rich output, how to build up the meeting memory with a minimum of additional effort, how to integrate meeting memory into organizati...

  12. All-spin logic operations: Memory device and reconfigurable computing

    Science.gov (United States)

    Patra, Moumita; Maiti, Santanu K.

    2018-02-01

    Exploiting spin degree of freedom of electron a new proposal is given to characterize spin-based logical operations using a quantum interferometer that can be utilized as a programmable spin logic device (PSLD). The ON and OFF states of both inputs and outputs are described by spin state only, circumventing spin-to-charge conversion at every stage as often used in conventional devices with the inclusion of extra hardware that can eventually diminish the efficiency. All possible logic functions can be engineered from a single device without redesigning the circuit which certainly offers the opportunities of designing new generation spintronic devices. Moreover, we also discuss the utilization of the present model as a memory device and suitable computing operations with proposed experimental setups.

  13. Irrelevant sensory stimuli interfere with working memory storage: evidence from a computational model of prefrontal neurons.

    Science.gov (United States)

    Bancroft, Tyler D; Hockley, William E; Servos, Philip

    2013-03-01

    The encoding of irrelevant stimuli into the memory store has previously been suggested as a mechanism of interference in working memory (e.g., Lange & Oberauer, Memory, 13, 333-339, 2005; Nairne, Memory & Cognition, 18, 251-269, 1990). Recently, Bancroft and Servos (Experimental Brain Research, 208, 529-532, 2011) used a tactile working memory task to provide experimental evidence that irrelevant stimuli were, in fact, encoded into working memory. In the present study, we replicated Bancroft and Servos's experimental findings using a biologically based computational model of prefrontal neurons, providing a neurocomputational model of overwriting in working memory. Furthermore, our modeling results show that inhibition acts to protect the contents of working memory, and they suggest a need for further experimental research into the capacity of vibrotactile working memory.

  14. EEG correlates of task engagement and mental workload in vigilance, learning, and memory tasks.

    Science.gov (United States)

    Berka, Chris; Levendowski, Daniel J; Lumicao, Michelle N; Yau, Alan; Davis, Gene; Zivkovic, Vladimir T; Olmstead, Richard E; Tremoulet, Patrice D; Craven, Patrick L

    2007-05-01

    The ability to continuously and unobtrusively monitor levels of task engagement and mental workload in an operational environment could be useful in identifying more accurate and efficient methods for humans to interact with technology. This information could also be used to optimize the design of safer, more efficient work environments that increase motivation and productivity. The present study explored the feasibility of monitoring electroencephalo-graphic (EEG) indices of engagement and workload acquired unobtrusively and quantified during performance of cognitive tests. EEG was acquired from 80 healthy participants with a wireless sensor headset (F3-F4,C3-C4,Cz-POz,F3-Cz,Fz-C3,Fz-POz) during tasks including: multi-level forward/backward-digit-span, grid-recall, trails, mental-addition, 20-min 3-Choice Vigilance, and image-learning and memory tests. EEG metrics for engagement and workload were calculated for each 1 -s of EEG. Across participants, engagement but not workload decreased over the 20-min vigilance test. Engagement and workload were significantly increased during the encoding period of verbal and image-learning and memory tests when compared with the recognition/ recall period. Workload but not engagement increased linearly as level of difficulty increased in forward and backward-digit-span, grid-recall, and mental-addition tests. EEG measures correlated with both subjective and objective performance metrics. These data in combination with previous studies suggest that EEG engagement reflects information-gathering, visual processing, and allocation of attention. EEG workload increases with increasing working memory load and during problem solving, integration of information, analytical reasoning, and may be more reflective of executive functions. Inspection of EEG on a second-by-second timescale revealed associations between workload and engagement levels when aligned with specific task events providing preliminary evidence that second

  15. Evaluation of auditory sensory memory of mentally retarded and nonretarded persons.

    Science.gov (United States)

    Campbell, E M; Meyer, P A

    1981-07-01

    Performance of mentally retarded and nonretarded persons was compared in two experiments designed to identify processes of auditory sensory memory. In one study backward masking of pure tones occurred for a group of retarded adolescents; however, no differences in masking functions were obtained for the retarded group and control groups of equal CA and MA. In the second study a gap-detection task was used as an apparent index of echoic trace durability. Since retarded persons were hypothesized to have a less durable echoic trace, the unique prediction was made that they would outperform control subjects on the task. The retarded group was significantly more accurate and exhibited a lower threshold than did the nonretarded, CA-matched control group. The applicability of these tasks for investigations of mental development was noted, and suggestions were made concerning improvements and extensions of the present research. A theoretical model was proposed to incorporate te current pattern of results.

  16. Computational and empirical simulations of selective memory impairments: Converging evidence for a single-system account of memory dissociations.

    Science.gov (United States)

    Curtis, Evan T; Jamieson, Randall K

    2018-04-01

    Current theory has divided memory into multiple systems, resulting in a fractionated account of human behaviour. By an alternative perspective, memory is a single system. However, debate over the details of different single-system theories has overshadowed the converging agreement among them, slowing the reunification of memory. Evidence in favour of dividing memory often takes the form of dissociations observed in amnesia, where amnesic patients are impaired on some memory tasks but not others. The dissociations are taken as evidence for separate explicit and implicit memory systems. We argue against this perspective. We simulate two key dissociations between classification and recognition in a computational model of memory, A Theory of Nonanalytic Association. We assume that amnesia reflects a quantitative difference in the quality of encoding. We also present empirical evidence that replicates the dissociations in healthy participants, simulating amnesic behaviour by reducing study time. In both analyses, we successfully reproduce the dissociations. We integrate our computational and empirical successes with the success of alternative models and manipulations and argue that our demonstrations, taken in concert with similar demonstrations with similar models, provide converging evidence for a more general set of single-system analyses that support the conclusion that a wide variety of memory phenomena can be explained by a unified and coherent set of principles.

  17. Spin-transfer torque magnetoresistive random-access memory technologies for normally off computing (invited)

    International Nuclear Information System (INIS)

    Ando, K.; Yuasa, S.; Fujita, S.; Ito, J.; Yoda, H.; Suzuki, Y.; Nakatani, Y.; Miyazaki, T.

    2014-01-01

    Most parts of present computer systems are made of volatile devices, and the power to supply them to avoid information loss causes huge energy losses. We can eliminate this meaningless energy loss by utilizing the non-volatile function of advanced spin-transfer torque magnetoresistive random-access memory (STT-MRAM) technology and create a new type of computer, i.e., normally off computers. Critical tasks to achieve normally off computers are implementations of STT-MRAM technologies in the main memory and low-level cache memories. STT-MRAM technology for applications to the main memory has been successfully developed by using perpendicular STT-MRAMs, and faster STT-MRAM technologies for applications to the cache memory are now being developed. The present status of STT-MRAMs and challenges that remain for normally off computers are discussed

  18. Programs for Testing Processor-in-Memory Computing Systems

    Science.gov (United States)

    Katz, Daniel S.

    2006-01-01

    The Multithreaded Microbenchmarks for Processor-In-Memory (PIM) Compilers, Simulators, and Hardware are computer programs arranged in a series for use in testing the performances of PIM computing systems, including compilers, simulators, and hardware. The programs at the beginning of the series test basic functionality; the programs at subsequent positions in the series test increasingly complex functionality. The programs are intended to be used while designing a PIM system, and can be used to verify that compilers, simulators, and hardware work correctly. The programs can also be used to enable designers of these system components to examine tradeoffs in implementation. Finally, these programs can be run on non-PIM hardware (either single-threaded or multithreaded) using the POSIX pthreads standard to verify that the benchmarks themselves operate correctly. [POSIX (Portable Operating System Interface for UNIX) is a set of standards that define how programs and operating systems interact with each other. pthreads is a library of pre-emptive thread routines that comply with one of the POSIX standards.

  19. Large-scale particle simulations in a virtual-memory computer

    International Nuclear Information System (INIS)

    Gray, P.C.; Wagner, J.S.; Tajima, T.; Million, R.

    1982-08-01

    Virtual memory computers are capable of executing large-scale particle simulations even when the memory requirements exceed the computer core size. The required address space is automatically mapped onto slow disc memory by the operating system. When the simulation size is very large, frequent random accesses to slow memory occur during the charge accumulation and particle pushing processes. Accesses to slow memory significantly reduce the execution rate of the simulation. We demonstrate in this paper that with the proper choice of sorting algorithm, a nominal amount of sorting to keep physically adjacent particles near particles with neighboring array indices can reduce random access to slow memory, increase the efficiency of the I/O system, and hence, reduce the required computing time

  20. Working Memory Interventions with Children: Classrooms or Computers?

    Science.gov (United States)

    Colmar, Susan; Double, Kit

    2017-01-01

    The importance of working memory to classroom functioning and academic outcomes has led to the development of many interventions designed to enhance students' working memory. In this article we briefly review the evidence for the relative effectiveness of classroom and computerised working memory interventions in bringing about measurable and…

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sophie Elizabeth Lind

    2014-12-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  4. Using Mental Imagery Processes for Teaching and Research in Mathematics and Computer Science

    Science.gov (United States)

    Arnoux, Pierre; Finkel, Alain

    2010-01-01

    The role of mental representations in mathematics and computer science (for teaching or research) is often downplayed or even completely ignored. Using an ongoing work on the subject, we argue for a more systematic study and use of mental representations, to get an intuition of mathematical concepts, and also to understand and build proofs. We…

  5. Paying attention to working memory: Similarities in the spatial distribution of attention in mental and physical space.

    Science.gov (United States)

    Sahan, Muhammet Ikbal; Verguts, Tom; Boehler, Carsten Nicolas; Pourtois, Gilles; Fias, Wim

    2016-08-01

    Selective attention is not limited to information that is physically present in the external world, but can also operate on mental representations in the internal world. However, it is not known whether the mechanisms of attentional selection operate in similar fashions in physical and mental space. We studied the spatial distributions of attention for items in physical and mental space by comparing how successfully distractors were rejected at varying distances from the attended location. The results indicated very similar distribution characteristics of spatial attention in physical and mental space. Specifically, we found that performance monotonically improved with increasing distractor distance relative to the attended location, suggesting that distractor confusability is particularly pronounced for nearby distractors, relative to distractors farther away. The present findings suggest that mental representations preserve their spatial configuration in working memory, and that similar mechanistic principles underlie selective attention in physical and in mental space.

  6. Studies on the Mental Processes in Translation Memory-assisted Translation – the State of the Art

    DEFF Research Database (Denmark)

    Christensen, Tina Paulsen

    2011-01-01

    This article reviews research on the mental translation processes involved in translation memory-assisted translation. First, based on recent developments in cognitive science the article provides a working definition of mental TM research. Next the article analyses a selection of mental TM studies...... with a view to discovering their aims, data, methods and results. In doing so, the paper attempts to find out what we know by now about the mental aspects of translation memory-assisted translation. The analysis suggests fruitful avenues for future research and concludes that particularly more research...... is needed which takes into account the recent developments within TM technology and looks into both internal and external translation processes....

  7. Evaluation of External Memory Access Performance on a High-End FPGA Hybrid Computer

    Directory of Open Access Journals (Sweden)

    Konstantinos Kalaitzis

    2016-10-01

    Full Text Available The motivation of this research was to evaluate the main memory performance of a hybrid super computer such as the Convey HC-x, and ascertain how the controller performs in several access scenarios, vis-à-vis hand-coded memory prefetches. Such memory patterns are very useful in stencil computations. The theoretical bandwidth of the memory of the Convey is compared with the results of our measurements. The accurate study of the memory subsystem is particularly useful for users when they are developing their application-specific personality. Experiments were performed to measure the bandwidth between the coprocessor and the memory subsystem. The experiments aimed mainly at measuring the reading access speed of the memory from Application Engines (FPGAs. Different ways of accessing data were used in order to find the most efficient way to access memory. This way was proposed for future work in the Convey HC-x. When performing a series of accesses to memory, non-uniform latencies occur. The Memory Controller of the Convey HC-x in the coprocessor attempts to cover this latency. We measure memory efficiency as a ratio of the number of memory accesses and the number of execution cycles. The result of this measurement converges to one in most cases. In addition, we performed experiments with hand-coded memory accesses. The analysis of the experimental results shows how the memory subsystem and Memory Controllers work. From this work we conclude that the memory controllers do an excellent job, largely because (transparently to the user they seem to cache large amounts of data, and hence hand-coding is not needed in most situations.

  8. Continuous-variable quantum computing in optical time-frequency modes using quantum memories.

    Science.gov (United States)

    Humphreys, Peter C; Kolthammer, W Steven; Nunn, Joshua; Barbieri, Marco; Datta, Animesh; Walmsley, Ian A

    2014-09-26

    We develop a scheme for time-frequency encoded continuous-variable cluster-state quantum computing using quantum memories. In particular, we propose a method to produce, manipulate, and measure two-dimensional cluster states in a single spatial mode by exploiting the intrinsic time-frequency selectivity of Raman quantum memories. Time-frequency encoding enables the scheme to be extremely compact, requiring a number of memories that are a linear function of only the number of different frequencies in which the computational state is encoded, independent of its temporal duration. We therefore show that quantum memories can be a powerful component for scalable photonic quantum information processing architectures.

  9. A 32-bit computer for large memory applications on the FASTBUS

    International Nuclear Information System (INIS)

    Kellner, R.; Blossom, J.M.; Hung, J.P.

    1985-01-01

    A FASTBUS based 32-bit computer is being built at Los Alamos National Laboratory for use in systems requiring large fast memory in the FASTBUS environment. A separate local execution bus allows data reduction to proceed concurrently with other FASTBUS operations. The computer, which can operate in either master or slave mode, includes the National Semiconductor NS32032 chip set with demand paged memory management, floating point slave processor, interrupt control unit, timers, and time-of-day clock. The 16.0 megabytes of random access memory are interleaved to allow windowed direct memory access on and off the FASTBUS at 80 megabytes per second

  10. Reflecting on imagery: a clinical perspective and overview of the special issue of memory on mental imagery and memory in psychopathology.

    Science.gov (United States)

    Hackmann, Ann; Holmes, Emily A

    2004-07-01

    The authors provide an overview of the papers in the special issue of Memory on mental imagery and memory in psychopathology. The papers address emotional, intrusive mental imagery across a range of psychological disorders including post-traumatic stress disorder (PTSD), agoraphobia, body dysmorphic disorder, mood disorders, and psychosis. They include work on information processing issues including modelling cravings, conditioning, and aversions, as well as imagery qualities such as vividness and emotionality. The overview aims to place the articles in a broader context and draw out some exciting implications of this novel work. It provides a clinical context to the recent growth in this area from a cognitive behavioural therapy (CBT) perspective. We begin with PTSD, and consider links to imagery in other disorders. The clinical implications stemming from this empirical work and from autobiographical memory theory are discussed. These include consideration of a variety of techniques for eliminating troublesome imagery, and creating healthy, realistic alternatives.

  11. Adaptive Dynamic Process Scheduling on Distributed Memory Parallel Computers

    Directory of Open Access Journals (Sweden)

    Wei Shu

    1994-01-01

    Full Text Available One of the challenges in programming distributed memory parallel machines is deciding how to allocate work to processors. This problem is particularly important for computations with unpredictable dynamic behaviors or irregular structures. We present a scheme for dynamic scheduling of medium-grained processes that is useful in this context. The adaptive contracting within neighborhood (ACWN is a dynamic, distributed, load-dependent, and scalable scheme. It deals with dynamic and unpredictable creation of processes and adapts to different systems. The scheme is described and contrasted with two other schemes that have been proposed in this context, namely the randomized allocation and the gradient model. The performance of the three schemes on an Intel iPSC/2 hypercube is presented and analyzed. The experimental results show that even though the ACWN algorithm incurs somewhat larger overhead than the randomized allocation, it achieves better performance in most cases due to its adaptiveness. Its feature of quickly spreading the work helps it outperform the gradient model in performance and scalability.

  12. Wearable Intrinsically Soft, Stretchable, Flexible Devices for Memories and Computing.

    Science.gov (United States)

    Rajan, Krishna; Garofalo, Erik; Chiolerio, Alessandro

    2018-01-27

    A recent trend in the development of high mass consumption electron devices is towards electronic textiles (e-textiles), smart wearable devices, smart clothes, and flexible or printable electronics. Intrinsically soft, stretchable, flexible, Wearable Memories and Computing devices (WMCs) bring us closer to sci-fi scenarios, where future electronic systems are totally integrated in our everyday outfits and help us in achieving a higher comfort level, interacting for us with other digital devices such as smartphones and domotics, or with analog devices, such as our brain/peripheral nervous system. WMC will enable each of us to contribute to open and big data systems as individual nodes, providing real-time information about physical and environmental parameters (including air pollution monitoring, sound and light pollution, chemical or radioactive fallout alert, network availability, and so on). Furthermore, WMC could be directly connected to human brain and enable extremely fast operation and unprecedented interface complexity, directly mapping the continuous states available to biological systems. This review focuses on recent advances in nanotechnology and materials science and pays particular attention to any result and promising technology to enable intrinsically soft, stretchable, flexible WMC.

  13. Cone-Beam Computed Tomography Evaluation of Mental Foramen Variations: A Preliminary Study

    International Nuclear Information System (INIS)

    Sheikhi, Mahnaz; Karbasi Kheir, Mitra; Hekmatian, Ehsan

    2015-01-01

    Background. Mental foramen is important in surgical operations of premolars because it transfers the mental nerves and vessels. This study evaluated the variations of mental foramen by cone-beam computed tomography among a selected Iranian population. Materials and Methods. A total number of 180 cone-beam computed tomography projections were analyzed in terms of shape, size, direction, and horizontal and vertical positions of mental foramen in the right and left sides. Results. The most common shape was oval, opening direction was posterior-superior, horizontal position was in line with second premolar, and vertical position was apical to the adjacent dental root. The mean of foremen diameter was 3.59 mm. Conclusion. In addition to the most common types of mental foramen, other variations exist, too. Hence, it reflects the significance of preoperative radiographic examinations, especially 3-dimensional images to prevent nerve damage

  14. Ring interconnection for distributed memory automation and computing system

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradov, V I [Inst. for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation)

    1996-12-31

    Problems of development of measurement, acquisition and central systems based on a distributed memory and a ring interface are discussed. It has been found that the RAM LINK-type protocol can be used for ringlet links in non-symmetrical distributed memory architecture multiprocessor system interaction. 5 refs.

  15. The Sensitivity of Memory Consolidation and Reconsolidation to Inhibitors of Protein Synthesis and Kinases: Computational Analysis

    Science.gov (United States)

    Zhang, Yili; Smolen, Paul; Baxter, Douglas A.; Byrne, John H.

    2010-01-01

    Memory consolidation and reconsolidation require kinase activation and protein synthesis. Blocking either process during or shortly after training or recall disrupts memory stabilization, which suggests the existence of a critical time window during which these processes are necessary. Using a computational model of kinase synthesis and…

  16. Effects of Target Probability and Memory Demands on the Vigilance of Adults with and without Mental Retardation.

    Science.gov (United States)

    Tomporowski, Phillip D.; Tinsley, Veronica

    1994-01-01

    The vigilance of young adults with and without mild mental retardation (MR) was compared, with subjects performing two memory demanding, cognitively based tests. The vigilance decrement of MR adults declined more rapidly than did the vigilance of non-MR adults, due to an interaction between target detectability and response bias, and poor target…

  17. Computational cost of isogeometric multi-frontal solvers on parallel distributed memory machines

    KAUST Repository

    Woźniak, Maciej; Paszyński, Maciej R.; Pardo, D.; Dalcin, Lisandro; Calo, Victor M.

    2015-01-01

    This paper derives theoretical estimates of the computational cost for isogeometric multi-frontal direct solver executed on parallel distributed memory machines. We show theoretically that for the Cp-1 global continuity of the isogeometric solution

  18. Modulation of visual cortical excitability by working memory: effect of luminance contrast of mental imagery

    Directory of Open Access Journals (Sweden)

    Zaira eCattaneo

    2011-02-01

    Full Text Available Although much is known about the impact of stimulus properties such as luminance contrast, spatial frequency and orientation on visually evoked neural activity, much less is known about how they modulate neural activity when they are properties of a mental image held in working memory (WM. Here we addressed this question by investigating how a parametric manipulation of an imagined stimulus attribute affects neuronal excitability in the early visual cortex. We manipulated luminance contrast, a stimulus property known to strongly affect the magnitude of neuronal responses in early visual areas. Luminance contrast modulated neuronal excitability, as assessed by the frequency of phosphenes induced by transcranial magnetic stimulation (TMS with the exact nature of this modulation depending on TMS intensity. These results point to a strong overlap in the neuronal processes underlying visual perception and mental imagery: not only does WM maintenance selectively engage neurons which are tuned to the maintained attribute (as has previously been shown, but the extent to which those neurons are activated depends on the luminance contrast (as is the case with visually-evoked responses. From a methodological viewpoint, these results suggest that assessment of visual cortical excitability using TMS is affected by the TMS intensity used to probe the neuronal population.

  19. Accessory mental foramen: A rare anatomical variation detected by cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Marianna Guanaes Gomes; De Faro Valverde, Ludmila; Vidal, Manuela Torres Andion; Crusoe-Rebello, Ieda Margarida [Dept. of Oral Radiology, School of Dentistry, Federal University of Bahia, Salvador (Brazil)

    2015-03-15

    The mental foramen is a bilateral opening in the vestibular portion of the mandible through which nerve endings, such as the mental nerve, emerge. In general, the mental foramen is located between the lower premolars. This region is a common area for the placement of dental implants. It is very important to identify anatomical variations in presurgical imaging exams since damage to neurovascular bundles may have a direct influence on treatment success. In the hemimandible, the mental foramen normally appears as a single structure, but there are some rare reports on the presence and number of anatomical variations; these variations may include accessory foramina. The present report describes the presence of accessory mental foramina in the right mandible, as detected by cone-beam computed tomography before dental implant placement.

  20. Efficient Numeric and Geometric Computations using Heterogeneous Shared Memory Architectures

    Science.gov (United States)

    2017-10-04

    to the memory architectures of CPUs and GPUs to obtain good performance and result in good memory performance using cache management. These methods ...Accomplishments: The PI and students has developed new methods for path and ray tracing and their Report Date: 14-Oct-2017 INVESTIGATOR(S): Phone...The efficiency of our method makes it a good candidate for forming hybrid schemes with wave-based models. One possibility is to couple the ray curve

  1. Projection multiplex recording of computer-synthesised one-dimensional Fourier holograms for holographic memory systems: mathematical and experimental modelling

    Energy Technology Data Exchange (ETDEWEB)

    Betin, A Yu; Bobrinev, V I; Verenikina, N M; Donchenko, S S; Odinokov, S B [Research Institute ' Radiotronics and Laser Engineering' , Bauman Moscow State Technical University, Moscow (Russian Federation); Evtikhiev, N N; Zlokazov, E Yu; Starikov, S N; Starikov, R S [National Reseach Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2015-08-31

    A multiplex method of recording computer-synthesised one-dimensional Fourier holograms intended for holographic memory devices is proposed. The method potentially allows increasing the recording density in the previously proposed holographic memory system based on the computer synthesis and projection recording of data page holograms. (holographic memory)

  2. Computer Game Play Reduces Intrusive Memories of Experimental Trauma via Reconsolidation-Update Mechanisms.

    Science.gov (United States)

    James, Ella L; Bonsall, Michael B; Hoppitt, Laura; Tunbridge, Elizabeth M; Geddes, John R; Milton, Amy L; Holmes, Emily A

    2015-08-01

    Memory of a traumatic event becomes consolidated within hours. Intrusive memories can then flash back repeatedly into the mind's eye and cause distress. We investigated whether reconsolidation-the process during which memories become malleable when recalled-can be blocked using a cognitive task and whether such an approach can reduce these unbidden intrusions. We predicted that reconsolidation of a reactivated visual memory of experimental trauma could be disrupted by engaging in a visuospatial task that would compete for visual working memory resources. We showed that intrusive memories were virtually abolished by playing the computer game Tetris following a memory-reactivation task 24 hr after initial exposure to experimental trauma. Furthermore, both memory reactivation and playing Tetris were required to reduce subsequent intrusions (Experiment 2), consistent with reconsolidation-update mechanisms. A simple, noninvasive cognitive-task procedure administered after emotional memory has already consolidated (i.e., > 24 hours after exposure to experimental trauma) may prevent the recurrence of intrusive memories of those emotional events. © The Author(s) 2015.

  3. Electro-encephalogram based brain-computer interface: improved performance by mental practice and concentration skills.

    Science.gov (United States)

    Mahmoudi, Babak; Erfanian, Abbas

    2006-11-01

    Mental imagination is the essential part of the most EEG-based communication systems. Thus, the quality of mental rehearsal, the degree of imagined effort, and mind controllability should have a major effect on the performance of electro-encephalogram (EEG) based brain-computer interface (BCI). It is now well established that mental practice using motor imagery improves motor skills. The effects of mental practice on motor skill learning are the result of practice on central motor programming. According to this view, it seems logical that mental practice should modify the neuronal activity in the primary sensorimotor areas and consequently change the performance of EEG-based BCI. For developing a practical BCI system, recognizing the resting state with eyes opened and the imagined voluntary movement is important. For this purpose, the mind should be able to focus on a single goal for a period of time, without deviation to another context. In this work, we are going to examine the role of mental practice and concentration skills on the EEG control during imaginative hand movements. The results show that the mental practice and concentration can generally improve the classification accuracy of the EEG patterns. It is found that mental training has a significant effect on the classification accuracy over the primary motor cortex and frontal area.

  4. Gesturing during mental problem solving reduces eye movements, especially for individuals with lower visual working memory capacity.

    Science.gov (United States)

    Pouw, Wim T J L; Mavilidi, Myrto-Foteini; van Gog, Tamara; Paas, Fred

    2016-08-01

    Non-communicative hand gestures have been found to benefit problem-solving performance. These gestures seem to compensate for limited internal cognitive capacities, such as visual working memory capacity. Yet, it is not clear how gestures might perform this cognitive function. One hypothesis is that gesturing is a means to spatially index mental simulations, thereby reducing the need for visually projecting the mental simulation onto the visual presentation of the task. If that hypothesis is correct, less eye movements should be made when participants gesture during problem solving than when they do not gesture. We therefore used mobile eye tracking to investigate the effect of co-thought gesturing and visual working memory capacity on eye movements during mental solving of the Tower of Hanoi problem. Results revealed that gesturing indeed reduced the number of eye movements (lower saccade counts), especially for participants with a relatively lower visual working memory capacity. Subsequent problem-solving performance was not affected by having (not) gestured during the mental solving phase. The current findings suggest that our understanding of gestures in problem solving could be improved by taking into account eye movements during gesturing.

  5. Method of computer generation and projection recording of microholograms for holographic memory systems: mathematical modelling and experimental implementation

    International Nuclear Information System (INIS)

    Betin, A Yu; Bobrinev, V I; Evtikhiev, N N; Zherdev, A Yu; Zlokazov, E Yu; Lushnikov, D S; Markin, V V; Odinokov, S B; Starikov, S N; Starikov, R S

    2013-01-01

    A method of computer generation and projection recording of microholograms for holographic memory systems is presented; the results of mathematical modelling and experimental implementation of the method are demonstrated. (holographic memory)

  6. Computer-Presented Organizational/Memory Aids as Instruction for Solving Pico-Fomi Problems.

    Science.gov (United States)

    Steinberg, Esther R.; And Others

    1985-01-01

    Describes investigation of effectiveness of computer-presented organizational/memory aids (matrix and verbal charts controlled by computer or learner) as instructional technique for solving Pico-Fomi problems, and the acquisition of deductive inference rules when such aids are present. Results indicate chart use control should be adapted to…

  7. Single-Chip Computers With Microelectromechanical Systems-Based Magnetic Memory

    NARCIS (Netherlands)

    Carley, L. Richard; Bain, James A.; Fedder, Gary K.; Greve, David W.; Guillou, David F.; Lu, Michael S.C.; Mukherjee, Tamal; Santhanam, Suresh; Abelmann, Leon; Min, Seungook

    This article describes an approach for implementing a complete computer system (CPU, RAM, I/O, and nonvolatile mass memory) on a single integrated-circuit substrate (a chip)—hence, the name "single-chip computer." The approach presented combines advances in the field of microelectromechanical

  8. Computer ethics and cyber laws to mental health professionals.

    Science.gov (United States)

    Raveesh, B N; Pande, Sanjay

    2004-04-01

    The explosive growth of computer and communications technology raises new legal and ethical challenges that reflect tensions between individual rights and societal needs. For instance, should cracking into a computer system be viewed as a petty prank, as trespassing, as theft, or as espionage? Should placing copyrighted material onto a public file server be treated as freedom of expression or as theft? Should ordinary communications be encrypted using codes that make it impossible for law-enforcement agencies to perform wiretaps? As we develop shared understandings and norms of behaviour, we are setting standards that will govern the information society for decades to come.

  9. Memory Space / Time Lived in Representation to Mental Maps: The Case of School Project "our neighborhood, our place"

    Directory of Open Access Journals (Sweden)

    Lucinei Pereira da Silva

    2012-12-01

    Full Text Available The representations and memory of living space are essential to developing mental maps and cartographic documents. In this regard this investigation as a primary objective to understand how mind maps can contribute pedagogically classes in Geography and History as well, breaking the dichotomy space / time. From the point of view of theoretical and methodological the research relied on the analysis of the school project “Our Neighborhood, Our Place” developed at the Municipal School “Vereador Hamilton Teodoro” in Governador Valadares (MG, along with a group of 7th grades from elementary school and the articulation of authors who discuss the concepts of representation, memory, space and place.

  10. Visuospatial memory computations during whole-body rotations in roll

    NARCIS (Netherlands)

    Pelt, S. van; Gisbergen, J.A.M. van; Medendorp, W.P.

    2005-01-01

    We used a memory-saccade task to test whether the location of a target, briefly presented before a whole-body rotation in roll, is stored in egocentric or in allocentric coordinates. To make this distinction, we exploited the fact that subjects, when tilted sideways in darkness, make systematic

  11. Attention-deficit/hyperactivity disorder: the impact of methylphenidate on working memory, inhibition capacity and mental flexibility.

    Science.gov (United States)

    Bolfer, Cristiana; Pacheco, Sandra Pasquali; Tsunemi, Miriam Harumi; Carreira, Walter Souza; Casella, Beatriz Borba; Casella, Erasmo Barbante

    2017-04-01

    To compare children with attention-deficit/hyperactivity disorder (ADHD), before and after the use of methylphenidate, and a control group, using tests of working memory, inhibition capacity and mental flexibility. Neuropsychological tests were administrated to 53 boys, 9-12 years old: the WISC-III digit span backward, and arithmetic; Stroop Color; and Trail Making Tests. The case group included 23 boys with ADHD, who were combined type, treatment-naive, and with normal intelligence without comorbidities. The control group (n = 30) were age and gender matched. After three months on methylphenidate, the ADHD children were retested. The control group was also retested after three months. Before treatment, ADHD children had lower scores than the control group on the tests (p ≤ 0.001) and after methylphenidate had fewer test errors than before (p ≤ 0.001). Methylphenidate treatment improves the working memory, inhibitory control and mental flexibility of ADHD boys.

  12. Information-Processing Correlates of Computer-Assisted Word Learning by Mentally Retarded Students.

    Science.gov (United States)

    Conners, Frances A.; Detterman, Douglas K.

    1987-01-01

    Nineteen moderately/severely retarded students (ages 9-22) completed ten 15-minute computer-assisted instruction sessions and seven basic cognitive tasks measuring simple learning, choice reaction time, relearning, probed recall, stimulus discrimination, tachictoscopic threshold, and recognition memory. Stimulus discrimination, probed recall, and…

  13. Detecting Mental States by Machine Learning Techniques: The Berlin Brain-Computer Interface

    Science.gov (United States)

    Blankertz, Benjamin; Tangermann, Michael; Vidaurre, Carmen; Dickhaus, Thorsten; Sannelli, Claudia; Popescu, Florin; Fazli, Siamac; Danóczy, Márton; Curio, Gabriel; Müller, Klaus-Robert

    The Berlin Brain-Computer Interface Brain-Computer Interface (BBCI) uses a machine learning approach to extract user-specific patterns from high-dimensional EEG-features optimized for revealing the user's mental state. Classical BCI applications are brain actuated tools for patients such as prostheses (see Section 4.1) or mental text entry systems ([1] and see [2-5] for an overview on BCI). In these applications, the BBCI uses natural motor skills of the users and specifically tailored pattern recognition algorithms for detecting the user's intent. But beyond rehabilitation, there is a wide range of possible applications in which BCI technology is used to monitor other mental states, often even covert ones (see also [6] in the fMRI realm). While this field is still largely unexplored, two examples from our studies are exemplified in Sections 4.3 and 4.4.

  14. Coping with the Stigma of Mental Illness: Empirically-Grounded Hypotheses from Computer Simulations

    Science.gov (United States)

    Kroska, Amy; Har, Sarah K.

    2011-01-01

    This research demonstrates how affect control theory and its computer program, "Interact", can be used to develop empirically-grounded hypotheses regarding the connection between cultural labels and behaviors. Our demonstration focuses on propositions in the modified labeling theory of mental illness. According to the MLT, negative societal…

  15. Attention and visual memory in visualization and computer graphics.

    Science.gov (United States)

    Healey, Christopher G; Enns, James T

    2012-07-01

    A fundamental goal of visualization is to produce images of data that support visual analysis, exploration, and discovery of novel insights. An important consideration during visualization design is the role of human visual perception. How we "see" details in an image can directly impact a viewer's efficiency and effectiveness. This paper surveys research on attention and visual perception, with a specific focus on results that have direct relevance to visualization and visual analytics. We discuss theories of low-level visual perception, then show how these findings form a foundation for more recent work on visual memory and visual attention. We conclude with a brief overview of how knowledge of visual attention and visual memory is being applied in visualization and graphics. We also discuss how challenges in visualization are motivating research in psychophysics.

  16. The Modified Telephone Interview for Cognitive Status is More Predictive of Memory Abilities Than the Mini-Mental State Examination.

    Science.gov (United States)

    Duff, Kevin; Tometich, Danielle; Dennett, Kathryn

    2015-09-01

    Although not as popular as the Mini-Mental State Examination (MMSE), the modified Telephone Interview for Cognitive Status (mTICS) has some distinct advantages when screening cognitive functioning in older adults. The current study compared these 2 cognitive screening measures in their ability to predict performance on a memory composite (ie, delayed recall of verbal and visual information) in a cohort of 121 community-dwelling older adults, both at baseline and after 1 year. Both the MMSE and the mTICS significantly correlated with the memory composite at baseline (r's of .41 and .62, respectively) and at 1 year (r's of .36 and .50, respectively). At baseline, stepwise linear regression indicated that the mTICS and gender best predicted the memory composite score (R (2) = .45, P similar. Despite its lesser popularity, the mTICS may be a more attractive option when screening for cognitive abilities in this age range. © The Author(s) 2015.

  17. Beyond Screening: Can the Mini-Mental State Examination be Used as an Exclusion Tool in a Memory Clinic?

    Science.gov (United States)

    Xu, Xin; Chong, Eddie; Hilal, Saima; Ikram, Mohammad Kamran; Venketasubramanian, Narayanaswamy; Chen, Christopher

    2015-11-04

    This study explores whether the Mini-Mental State Examination (MMSE) could reliably exclude definite dementia and dementia-free cases from requiring more extensive neuropsychological investigations in memory clinic settings in Singapore. Patients with memory complaints referred for possible dementia underwent the MMSE, followed by standardized neuropsychological and clinical assessments which led to a consensus diagnosis. MMSE cut-off points were derived stratified for education (less and equal/above primary level). Results show that after education stratification, using an optimal Positive Likelihood Ratio (PLR) and optimal Negative Likelihood Ratio (NLR), a higher percentage of patients were correctly identified as having dementia or dementia-free, with minimal misclassification rate. The finding suggests the MMSE can be used to exclude patients not requiring full neuropsychological assessments in a memory clinic.

  18. Forms of memory: Investigating the computational basis of semantic-episodic memory interactions

    NARCIS (Netherlands)

    Neville, D.A.

    2015-01-01

    The present thesis investigated how the memory systems related to the processing of semantic and episodic information combine to generate behavioural performance as measured in standard laboratory tasks. Across a series of behavioural experiment I looked at different types of interactions between

  19. A homotopy method for solving Riccati equations on a shared memory parallel computer

    International Nuclear Information System (INIS)

    Zigic, D.; Watson, L.T.; Collins, E.G. Jr.; Davis, L.D.

    1993-01-01

    Although there are numerous algorithms for solving Riccati equations, there still remains a need for algorithms which can operate efficiently on large problems and on parallel machines. This paper gives a new homotopy-based algorithm for solving Riccati equations on a shared memory parallel computer. The central part of the algorithm is the computation of the kernel of the Jacobian matrix, which is essential for the corrector iterations along the homotopy zero curve. Using a Schur decomposition the tensor product structure of various matrices can be efficiently exploited. The algorithm allows for efficient parallelization on shared memory machines

  20. Memory

    Science.gov (United States)

    ... it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few ...

  1. Distributed Cognition (DCOG): Foundations for a Computational Associative Memory Model

    National Research Council Canada - National Science Library

    Eggleston, Robert G; McCreight, Katherine L

    2006-01-01

    .... In this report, we describe the foundations of a different type of computational architecture; one that we believe will be less susceptible to cognitive brittleness and can better scale to complex and ill-structured work domains...

  2. [Short-and long-term effects of cannabinoids on memory, cognition and mental illness].

    Science.gov (United States)

    Sagie, Shira; Eliasi, Yehuda; Livneh, Ido; Bart, Yosi; Monovich, Einat

    2013-12-01

    Marijuana is considered the most commonly used drug in the world, with estimated millions of users. There is dissent in the medical world about the positive and negative effects of marijuana, and recently, a large research effort has been directed to that domain. The main influencing drug ingredient is THC, which acts on the cannabinoid system and binds to the CB1 receptor. The discovery of the receptor led to the finding of an endogenous ligand, anandamide, and another receptor-CB2. The researchers also discovered that cannabinoids have extensive biological activity, and its short and long-term effects may cause cognitive and emotional deficiencies. Findings show that the short-term effects, such as shortterm memory and verbal Learning, are reversible. However, despite the accumulation of evidence about long-term cognitive damage due to cannabis use, it is difficult to find unequivocal results, arising from the existence of many variables such as large differences between cannabis users, frequency of use, dosage and endogenous brain compensation. Apart from cognitive damage, current studies investigate how marijuana affects mental illness: a high correlation between cannabis use and schizophrenia was found and a high risk to undergo a psychotic attack. Furthermore, patients with schizophrenia who used cannabis showed a selective neuro-psychological disruption, and similar cognitive deficiencies and brain morphological changes were found among healthy cannabis users and schizophrenia patients. In contrast to the negative effects of marijuana including addiction, there are the medical uses: reducing pain, anxiety and nausea, increasing appetite and an anti-inflammatory activity. Medicalization of marijuana encourages frequent use, which may elevate depression.

  3. Memory intensive functional architecture for distributed computer control systems

    International Nuclear Information System (INIS)

    Dimmler, D.G.

    1983-10-01

    A memory-intensive functional architectue for distributed data-acquisition, monitoring, and control systems with large numbers of nodes has been conceptually developed and applied in several large-scale and some smaller systems. This discussion concentrates on: (1) the basic architecture; (2) recent expansions of the architecture which now become feasible in view of the rapidly developing component technologies in microprocessors and functional large-scale integration circuits; and (3) implementation of some key hardware and software structures and one system implementation which is a system for performing control and data acquisition of a neutron spectrometer at the Brookhaven High Flux Beam Reactor. The spectrometer is equipped with a large-area position-sensitive neutron detector

  4. AN ANALYSIS OF NUMBER SENSE AND MENTAL COMPUTATION IN THE LEARNING OF MATHEMATICS

    Directory of Open Access Journals (Sweden)

    Parmit Singh Aperapar

    2011-04-01

    Full Text Available The purpose of this research was to assess students’ understanding of number sense and mental computation among Form One, Form Two, Form Three and Form Four students. A total of 1756 students, ages ranging from 12 to 17 years, from thirteen schools in Selangor participated in this study. A majority (74.9% of these students obtained an A grade for their respective year-end school examinations. The design for this study was quantitative in nature where the data on student’s sense of numbers was collected using two instruments, namely, Number Sense Test and Mental Computation Test. Each of these instruments consisted of 50 and 45 items respectively. The results from this study indicate that students were not able to cope to the Number Sense Test as compared to the Mental Computation Test. The former unveils a low percentage of 37.3% to 47.7% as compared to the latter of 79% to 88.6% across the levels. In the number Sense Test, surprisingly, there was no significant difference in the results between Form 1 students and Form 2 students and also between Form 3 students and Form 4 students. This seems to indicate that as the number of years in schools increase, there is an increasing reliance on algorithm and procedures. Although in the literature it has been argued that including mental computation in a mathematics curriculum promotes number sense (McIntosh et. al., 1997; Reys, Reys, Nohda, & Emori, 2005, this was not the case in this study. It seems that an over reliance on paper and pencil computation at the expense of intuitive understanding of numbers is taking place among these students.

  5. Parallel grid generation algorithm for distributed memory computers

    Science.gov (United States)

    Moitra, Stuti; Moitra, Anutosh

    1994-01-01

    A parallel grid-generation algorithm and its implementation on the Intel iPSC/860 computer are described. The grid-generation scheme is based on an algebraic formulation of homotopic relations. Methods for utilizing the inherent parallelism of the grid-generation scheme are described, and implementation of multiple levELs of parallelism on multiple instruction multiple data machines are indicated. The algorithm is capable of providing near orthogonality and spacing control at solid boundaries while requiring minimal interprocessor communications. Results obtained on the Intel hypercube for a blended wing-body configuration are used to demonstrate the effectiveness of the algorithm. Fortran implementations bAsed on the native programming model of the iPSC/860 computer and the Express system of software tools are reported. Computational gains in execution time speed-up ratios are given.

  6. Effects of Violent and Non-Violent Computer Game Content on Memory Performance in Adolescents

    Science.gov (United States)

    Maass, Asja; Kollhorster, Kirsten; Riediger, Annemarie; MacDonald, Vanessa; Lohaus, Arnold

    2011-01-01

    The present study focuses on the short-term effects of electronic entertainment media on memory and learning processes. It compares the effects of violent versus non-violent computer game content in a condition of playing and in another condition of watching the same game. The participants consisted of 83 female and 94 male adolescents with a mean…

  7. Computer Simulations of Developmental Change: The Contributions of Working Memory Capacity and Long-Term Knowledge

    Science.gov (United States)

    Jones, Gary; Gobet, Fernand; Pine, Julian M.

    2008-01-01

    Increasing working memory (WM) capacity is often cited as a major influence on children's development and yet WM capacity is difficult to examine independently of long-term knowledge. A computational model of children's nonword repetition (NWR) performance is presented that independently manipulates long-term knowledge and WM capacity to determine…

  8. The Effects of 3D Computer Simulation on Biology Students' Achievement and Memory Retention

    Science.gov (United States)

    Elangovan, Tavasuria; Ismail, Zurida

    2014-01-01

    A quasi experimental study was conducted for six weeks to determine the effectiveness of two different 3D computer simulation based teaching methods, that is, realistic simulation and non-realistic simulation on Form Four Biology students' achievement and memory retention in Perak, Malaysia. A sample of 136 Form Four Biology students in Perak,…

  9. Explicit time integration of finite element models on a vectorized, concurrent computer with shared memory

    Science.gov (United States)

    Gilbertsen, Noreen D.; Belytschko, Ted

    1990-01-01

    The implementation of a nonlinear explicit program on a vectorized, concurrent computer with shared memory is described and studied. The conflict between vectorization and concurrency is described and some guidelines are given for optimal block sizes. Several example problems are summarized to illustrate the types of speed-ups which can be achieved by reprogramming as compared to compiler optimization.

  10. Effect of Computer-Presented Organizational/Memory Aids on Problem Solving Behavior.

    Science.gov (United States)

    Steinberg, Esther R.; And Others

    This research studied the effects of computer-presented organizational/memory aids on problem solving behavior. The aids were either matrix or verbal charts shown on the display screen next to the problem. The 104 college student subjects were randomly assigned to one of the four conditions: type of chart (matrix or verbal chart) and use of charts…

  11. From shoebox to performative agent: the computer as personal memory machine

    NARCIS (Netherlands)

    van Dijck, J.

    2005-01-01

    Digital technologies offer new opportunities in the everyday lives of people: with still expanding memory capacities, the computer is rapidly becoming a giant storage and processing facility for recording and retrieving ‘bits of life’. Software engineers and companies promise not only to expand the

  12. Effect of aging on performance, muscle activation and perceived stress during mentally demanding computer tasks

    DEFF Research Database (Denmark)

    Alkjaer, Tine; Pilegaard, Marianne; Bakke, Merete

    2005-01-01

    OBJECTIVES: This study examined the effects of age on performance, muscle activation, and perceived stress during computer tasks with different levels of mental demand. METHODS: Fifteen young and thirteen elderly women performed two computer tasks [color word test and reference task] with different...... levels of mental demand but similar physical demands. The performance (clicking frequency, percentage of correct answers, and response time for correct answers) and electromyography from the forearm, shoulder, and neck muscles were recorded. Visual analogue scales were used to measure the participants......' perception of the stress and difficulty related to the tasks. RESULTS: Performance decreased significantly in both groups during the color word test in comparison with performance on the reference task. However, the performance reduction was more pronounced in the elderly group than in the young group...

  13. Use of computers and Internet among people with severe mental illnesses at peer support centers.

    Science.gov (United States)

    Brunette, Mary F; Aschbrenner, Kelly A; Ferron, Joelle C; Ustinich, Lee; Kelly, Michael; Grinley, Thomas

    2017-12-01

    Peer support centers are an ideal setting where people with severe mental illnesses can access the Internet via computers for online health education, peer support, and behavioral treatments. The purpose of this study was to assess computer use and Internet access in peer support agencies. A peer-assisted survey assessed the frequency with which consumers in all 13 New Hampshire peer support centers (n = 702) used computers to access Internet resources. During the 30-day survey period, 200 of the 702 peer support consumers (28%) responded to the survey. More than 3 quarters (78.5%) of respondents had gone online to seek information in the past year. About half (49%) of respondents were interested in learning about online forums that would provide information and peer support for mental health issues. Peer support centers may be a useful venue for Web-based approaches to education, peer support, and intervention. Future research should assess facilitators and barriers to use of Web-based resources among people with severe mental illness in peer support centers. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. Memory allocation and computations for Laplace’s equation of 3-D arbitrary boundary problems

    Directory of Open Access Journals (Sweden)

    Tsay Tswn-Syau

    2017-01-01

    Full Text Available Computation iteration schemes and memory allocation technique for finite difference method were presented in this paper. The transformed form of a groundwater flow problem in the generalized curvilinear coordinates was taken to be the illustrating example and a 3-dimensional second order accurate 19-point scheme was presented. Traditional element-by-element methods (e.g. SOR are preferred since it is simple and memory efficient but time consuming in computation. For efficient memory allocation, an index method was presented to store the sparse non-symmetric matrix of the problem. For computations, conjugate-gradient-like methods were reported to be computationally efficient. Among them, using incomplete Choleski decomposition as preconditioner was reported to be good method for iteration convergence. In general, the developed index method in this paper has the following advantages: (1 adaptable to various governing and boundary conditions, (2 flexible for higher order approximation, (3 independence of problem dimension, (4 efficient for complex problems when global matrix is not symmetric, (5 convenience for general sparse matrices, (6 computationally efficient in the most time consuming procedure of matrix multiplication, and (7 applicable to any developed matrix solver.

  15. Investigating the validity and usability of an interactive computer programme for assessing competence in telephone-based mental health triage.

    Science.gov (United States)

    Sands, Natisha; Elsom, Stephen; Keppich-Arnold, Sandra; Henderson, Kathryn; King, Peter; Bourke-Finn, Karen; Brunning, Debra

    2016-02-01

    Telephone-based mental health triage services are frontline health-care providers that operate 24/7 to facilitate access to psychiatric assessment and intervention for people requiring assistance with a mental health problem. The mental health triage clinical role is complex, and the populations triage serves are typically high risk; yet to date, no evidence-based methods have been available to assess clinician competence to practice telephone-based mental health triage. The present study reports the findings of a study that investigated the validity and usability of the Mental Health Triage Competency Assessment Tool, an evidence-based, interactive computer programme designed to assist clinicians in developing and assessing competence to practice telephone-based mental health triage. © 2015 Australian College of Mental Health Nurses Inc.

  16. Fencing direct memory access data transfers in a parallel active messaging interface of a parallel computer

    Science.gov (United States)

    Blocksome, Michael A.; Mamidala, Amith R.

    2013-09-03

    Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to segments of shared random access memory through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and a segment of shared memory; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

  17. Memory Functioning and Mental Verbs Acquisition in Children with Specific Language Impairment

    Science.gov (United States)

    Spanoudis, George C.; Natsopoulos, Demetrios

    2011-01-01

    Memory and language operate in synergy. Recent literature stresses the importance of memory functioning in interpreting language deficits. Two groups of 50 children each, ages 8-12 were studied. The first group included children with specific language impairment, while the participants in the second group were typically developing children. The…

  18. Association between playing computer games and mental and social health among male adolescents in Iran in 2014

    OpenAIRE

    Mehrnoosh Mohammadi; Abdollah RezaeiDehaghani; Tayebeh Mehrabi; Ali RezaeiDehaghani

    2016-01-01

    Background: As adolescents spend much time on playing computer games, their mental and social effects should be considered. The present study aimed to investigate the association between playing computer games and the mental and social health among male adolescents in Iran in 2014. Materials and Methods: This is a cross-sectional study conducted on 210 adolescents selected by multi-stage random sampling. Data were collected by Goldberg and Hillier general health (28 items) and Kiez socia...

  19. Sex Differences in Mental Arithmetic, Digit Span, and "g" Defined as Working Memory Capacity

    Science.gov (United States)

    Lynn, Richard; Irwing, Paul

    2008-01-01

    Meta-analyses are presented of sex differences in (1) the (mental) arithmetic subtest of the Wechsler intelligence tests for children and adolescents (the WISC and WPPSI tests), showing that boys obtained a mean advantage of 0.11d; (2) the (mental) arithmetic subtest of the Wechsler intelligence tests for adults (the WAIS tests) showing a mean…

  20. Virtual memory support for distributed computing environments using a shared data object model

    Science.gov (United States)

    Huang, F.; Bacon, J.; Mapp, G.

    1995-12-01

    Conventional storage management systems provide one interface for accessing memory segments and another for accessing secondary storage objects. This hinders application programming and affects overall system performance due to mandatory data copying and user/kernel boundary crossings, which in the microkernel case may involve context switches. Memory-mapping techniques may be used to provide programmers with a unified view of the storage system. This paper extends such techniques to support a shared data object model for distributed computing environments in which good support for coherence and synchronization is essential. The approach is based on a microkernel, typed memory objects, and integrated coherence control. A microkernel architecture is used to support multiple coherence protocols and the addition of new protocols. Memory objects are typed and applications can choose the most suitable protocols for different types of object to avoid protocol mismatch. Low-level coherence control is integrated with high-level concurrency control so that the number of messages required to maintain memory coherence is reduced and system-wide synchronization is realized without severely impacting the system performance. These features together contribute a novel approach to the support for flexible coherence under application control.

  1. Computational cost estimates for parallel shared memory isogeometric multi-frontal solvers

    KAUST Repository

    Woźniak, Maciej

    2014-06-01

    In this paper we present computational cost estimates for parallel shared memory isogeometric multi-frontal solvers. The estimates show that the ideal isogeometric shared memory parallel direct solver scales as O( p2log(N/p)) for one dimensional problems, O(Np2) for two dimensional problems, and O(N4/3p2) for three dimensional problems, where N is the number of degrees of freedom, and p is the polynomial order of approximation. The computational costs of the shared memory parallel isogeometric direct solver are compared with those corresponding to the sequential isogeometric direct solver, being the latest equal to O(N p2) for the one dimensional case, O(N1.5p3) for the two dimensional case, and O(N2p3) for the three dimensional case. The shared memory version significantly reduces both the scalability in terms of N and p. Theoretical estimates are compared with numerical experiments performed with linear, quadratic, cubic, quartic, and quintic B-splines, in one and two spatial dimensions. © 2014 Elsevier Ltd. All rights reserved.

  2. Computational cost estimates for parallel shared memory isogeometric multi-frontal solvers

    KAUST Repository

    Woźniak, Maciej; Kuźnik, Krzysztof M.; Paszyński, Maciej R.; Calo, Victor M.; Pardo, D.

    2014-01-01

    In this paper we present computational cost estimates for parallel shared memory isogeometric multi-frontal solvers. The estimates show that the ideal isogeometric shared memory parallel direct solver scales as O( p2log(N/p)) for one dimensional problems, O(Np2) for two dimensional problems, and O(N4/3p2) for three dimensional problems, where N is the number of degrees of freedom, and p is the polynomial order of approximation. The computational costs of the shared memory parallel isogeometric direct solver are compared with those corresponding to the sequential isogeometric direct solver, being the latest equal to O(N p2) for the one dimensional case, O(N1.5p3) for the two dimensional case, and O(N2p3) for the three dimensional case. The shared memory version significantly reduces both the scalability in terms of N and p. Theoretical estimates are compared with numerical experiments performed with linear, quadratic, cubic, quartic, and quintic B-splines, in one and two spatial dimensions. © 2014 Elsevier Ltd. All rights reserved.

  3. NATO Advanced Research Workshop on Exploiting Mental Imagery with Computers in Mathematics Education

    CERN Document Server

    Mason, John

    1995-01-01

    The advent of fast and sophisticated computer graphics has brought dynamic and interactive images under the control of professional mathematicians and mathematics teachers. This volume in the NATO Special Programme on Advanced Educational Technology takes a comprehensive and critical look at how the computer can support the use of visual images in mathematical problem solving. The contributions are written by researchers and teachers from a variety of disciplines including computer science, mathematics, mathematics education, psychology, and design. Some focus on the use of external visual images and others on the development of individual mental imagery. The book is the first collected volume in a research area that is developing rapidly, and the authors pose some challenging new questions.

  4. Exploiting short-term memory in soft body dynamics as a computational resource.

    Science.gov (United States)

    Nakajima, K; Li, T; Hauser, H; Pfeifer, R

    2014-11-06

    Soft materials are not only highly deformable, but they also possess rich and diverse body dynamics. Soft body dynamics exhibit a variety of properties, including nonlinearity, elasticity and potentially infinitely many degrees of freedom. Here, we demonstrate that such soft body dynamics can be employed to conduct certain types of computation. Using body dynamics generated from a soft silicone arm, we show that they can be exploited to emulate functions that require memory and to embed robust closed-loop control into the arm. Our results suggest that soft body dynamics have a short-term memory and can serve as a computational resource. This finding paves the way towards exploiting passive body dynamics for control of a large class of underactuated systems. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  5. Cognitive cooperation groups mediated by computers and internet present significant improvement of cognitive status in older adults with memory complaints: a controlled prospective study

    Directory of Open Access Journals (Sweden)

    Rodrigo de Rosso Krug

    Full Text Available ABSTRACT Objective To estimate the effect of participating in cognitive cooperation groups, mediated by computers and the internet, on the Mini-Mental State Examination (MMSE percent variation of outpatients with memory complaints attending two memory clinics. Methods A prospective controlled intervention study carried out from 2006 to 2013 with 293 elders. The intervention group (n = 160 attended a cognitive cooperation group (20 sessions of 1.5 hours each. The control group (n = 133 received routine medical care. Outcome was the percent variation in the MMSE. Control variables included gender, age, marital status, schooling, hypertension, diabetes, dyslipidaemia, hypothyroidism, depression, vascular diseases, polymedication, use of benzodiazepines, exposure to tobacco, sedentary lifestyle, obesity and functional capacity. The final model was obtained by multivariate linear regression. Results The intervention group obtained an independent positive variation of 24.39% (CI 95% = 14.86/33.91 in the MMSE compared to the control group. Conclusion The results suggested that cognitive cooperation groups, mediated by computers and the internet, are associated with cognitive status improvement of older adults in memory clinics.

  6. Novel spintronics devices for memory and logic: prospects and challenges for room temperature all spin computing

    Science.gov (United States)

    Wang, Jian-Ping

    An energy efficient memory and logic device for the post-CMOS era has been the goal of a variety of research fields. The limits of scaling, which we expect to reach by the year 2025, demand that future advances in computational power will not be realized from ever-shrinking device sizes, but rather by innovative designs and new materials and physics. Magnetoresistive based devices have been a promising candidate for future integrated magnetic computation because of its unique non-volatility and functionalities. The application of perpendicular magnetic anisotropy for potential STT-RAM application was demonstrated and later has been intensively investigated by both academia and industry groups, but there is no clear path way how scaling will eventually work for both memory and logic applications. One of main reasons is that there is no demonstrated material stack candidate that could lead to a scaling scheme down to sub 10 nm. Another challenge for the usage of magnetoresistive based devices for logic application is its available switching speed and writing energy. Although a good progress has been made to demonstrate the fast switching of a thermally stable magnetic tunnel junction (MTJ) down to 165 ps, it is still several times slower than its CMOS counterpart. In this talk, I will review the recent progress by my research group and my C-SPIN colleagues, then discuss the opportunities, challenges and some potential path ways for magnetoresitive based devices for memory and logic applications and their integration for room temperature all spin computing system.

  7. PREFACE: Special section on Computational Fluid Dynamics—in memory of Professor Kunio Kuwahara Special section on Computational Fluid Dynamics—in memory of Professor Kunio Kuwahara

    Science.gov (United States)

    Ishii, Katsuya

    2011-08-01

    This issue includes a special section on computational fluid dynamics (CFD) in memory of the late Professor Kunio Kuwahara, who passed away on 15 September 2008, at the age of 66. In this special section, five articles are included that are based on the lectures and discussions at `The 7th International Nobeyama Workshop on CFD: To the Memory of Professor Kuwahara' held in Tokyo on 23 and 24 September 2009. Professor Kuwahara started his research in fluid dynamics under Professor Imai at the University of Tokyo. His first paper was published in 1969 with the title 'Steady Viscous Flow within Circular Boundary', with Professor Imai. In this paper, he combined theoretical and numerical methods in fluid dynamics. Since that time, he made significant and seminal contributions to computational fluid dynamics. He undertook pioneering numerical studies on the vortex method in 1970s. From then to the early nineties, he developed numerical analyses on a variety of three-dimensional unsteady phenomena of incompressible and compressible fluid flows and/or complex fluid flows using his own supercomputers with academic and industrial co-workers and members of his private research institute, ICFD in Tokyo. In addition, a number of senior and young researchers of fluid mechanics around the world were invited to ICFD and the Nobeyama workshops, which were held near his villa, and they intensively discussed new frontier problems of fluid physics and fluid engineering at Professor Kuwahara's kind hospitality. At the memorial Nobeyama workshop held in 2009, 24 overseas speakers presented their papers, including the talks of Dr J P Boris (Naval Research Laboratory), Dr E S Oran (Naval Research Laboratory), Professor Z J Wang (Iowa State University), Dr M Meinke (RWTH Aachen), Professor K Ghia (University of Cincinnati), Professor U Ghia (University of Cincinnati), Professor F Hussain (University of Houston), Professor M Farge (École Normale Superieure), Professor J Y Yong (National

  8. System of common usage on the base of external memory devices and the SM-3 computer

    International Nuclear Information System (INIS)

    Baluka, G.; Vasin, A.Yu.; Ermakov, V.A.; Zhukov, G.P.; Zimin, G.N.; Namsraj, Yu.; Ostrovnoj, A.I.; Savvateev, A.S.; Salamatin, I.M.; Yanovskij, G.Ya.

    1980-01-01

    An easily modified system of common usage on the base of external memories and a SM-3 minicomputer replacing some pulse analysers is described. The system has merits of PA and is more advantageous with regard to effectiveness of equipment using, the possibility of changing configuration and functions, the data protection against losses due to user errors and some failures, price of one registration channel, place occupied. The system of common usage is intended for the IBR-2 pulse reactor computing centre. It is designed using the SANPO system means for SM-3 computer [ru

  9. A learnable parallel processing architecture towards unity of memory and computing.

    Science.gov (United States)

    Li, H; Gao, B; Chen, Z; Zhao, Y; Huang, P; Ye, H; Liu, L; Liu, X; Kang, J

    2015-08-14

    Developing energy-efficient parallel information processing systems beyond von Neumann architecture is a long-standing goal of modern information technologies. The widely used von Neumann computer architecture separates memory and computing units, which leads to energy-hungry data movement when computers work. In order to meet the need of efficient information processing for the data-driven applications such as big data and Internet of Things, an energy-efficient processing architecture beyond von Neumann is critical for the information society. Here we show a non-von Neumann architecture built of resistive switching (RS) devices named "iMemComp", where memory and logic are unified with single-type devices. Leveraging nonvolatile nature and structural parallelism of crossbar RS arrays, we have equipped "iMemComp" with capabilities of computing in parallel and learning user-defined logic functions for large-scale information processing tasks. Such architecture eliminates the energy-hungry data movement in von Neumann computers. Compared with contemporary silicon technology, adder circuits based on "iMemComp" can improve the speed by 76.8% and the power dissipation by 60.3%, together with a 700 times aggressive reduction in the circuit area.

  10. A learnable parallel processing architecture towards unity of memory and computing

    Science.gov (United States)

    Li, H.; Gao, B.; Chen, Z.; Zhao, Y.; Huang, P.; Ye, H.; Liu, L.; Liu, X.; Kang, J.

    2015-08-01

    Developing energy-efficient parallel information processing systems beyond von Neumann architecture is a long-standing goal of modern information technologies. The widely used von Neumann computer architecture separates memory and computing units, which leads to energy-hungry data movement when computers work. In order to meet the need of efficient information processing for the data-driven applications such as big data and Internet of Things, an energy-efficient processing architecture beyond von Neumann is critical for the information society. Here we show a non-von Neumann architecture built of resistive switching (RS) devices named “iMemComp”, where memory and logic are unified with single-type devices. Leveraging nonvolatile nature and structural parallelism of crossbar RS arrays, we have equipped “iMemComp” with capabilities of computing in parallel and learning user-defined logic functions for large-scale information processing tasks. Such architecture eliminates the energy-hungry data movement in von Neumann computers. Compared with contemporary silicon technology, adder circuits based on “iMemComp” can improve the speed by 76.8% and the power dissipation by 60.3%, together with a 700 times aggressive reduction in the circuit area.

  11. The role of working memory on measuring mental models of physical systems

    Directory of Open Access Journals (Sweden)

    José F. Quesada

    2001-01-01

    Full Text Available Hasta ahora no ha existido un acuerdo sobre la definición correcta de Modelo Mental de un sistema físico y sobre la forma como podemos inferir el Modelo Mental que una persona tiene del sistema con el que está interactuando. En este artículo se describe una investigación encaminada a solucionar estos problemas con la propuesta de una definición según la cual un Modelos Mental es una representación dinámica creada en la Memoria Operativa, combinando la información almacenada en la Memoria a Largo Plazo y las características extraídas del ambiente. Las hipótesis derivadas de esta propuesta se prueban en tres experimentos y se discuten las implicaciones que sus resultados tienen para la investigación futura sobre Modelos Mentales.

  12. Age-related brain atrophy and mental deterioration - a study with computed tomography

    International Nuclear Information System (INIS)

    Ito, M.; Hatazawa, J.; Yamaura, H.; Matsuzawa, T.

    1981-01-01

    The relation of brain atrophy measured with computed tomography (CT) to mental deterioration on living people was studied. A newly improved technique for quantitative measurement of brain atrophy was developed. The pixels inside the head slices were divided into three parts; brain skull, and cerebrospinal fluid according to their CT number. The volume of brain, CSF, and cranial cavity were calculated by counting the number of pixels of each tissue. Results from 130 normal brains showed that the CSF volume was constant at about 16 ml through 20-39 years old. After 40 years the mean CSF volume increased drastically and reached 71 ml in the seventies. The volume of the brain was standardized for comparison between different-sized heads (brain volume index: BVI). The mean BVI decreased with statistical significance after 40 years of age. Mental function of these persons were evaluated using Hasegawa's dementia rating scale for the elderly. Progression of brain atrophy accompanied loss of mental activities (p<0.01). (author)

  13. Mental Objects in Working Memory: Development of Basic Capacity or of Cognitive Completion?

    Science.gov (United States)

    Cowan, Nelson

    2018-01-01

    Working memory is the small amount of information that we hold in mind and use to carry out cognitive processes such as language comprehension and production, problem-solving, and decision-making. In order to understand cognitive development, it would be helpful to know whether working memory increases in capacity with development and, if so, how and why. I will focus on two major stumbling blocks toward understanding working memory development, namely that (1) many potentially relevant aspects of the mind change in parallel during development, obscuring the role of any one change; and (2) one cannot use the same test procedure from infancy to adulthood, complicating comparisons across age groups. With regard to the first stumbling block, the parallel development of different aspects of the mind, we discuss research in which attempts were made to hold constant some factors (knowledge, strategies, direction of attention) to investigate whether developmental differences remain. With regard to the second stumbling block, procedural differences in tests at different age groups, I suggest ways in which the results might be reconciled across procedures. I highlight the value of pursuing research that could distinguish between two different key hypotheses that emerge: that there is a developmental increase in the number of working memory slots (or in a basic resource that holds items in working memory), and that there is a developmental increase in the amount of detail that each of these slots can hold. PMID:28215289

  14. Mental Objects in Working Memory: Development of Basic Capacity or of Cognitive Completion?

    Science.gov (United States)

    Cowan, N

    2017-01-01

    Working memory is the small amount of information that we hold in mind and use to carry out cognitive processes such as language comprehension and production, problem solving, and decision making. In order to understand cognitive development, it would be helpful to know whether working memory increases in capacity with development and, if so, how and why. I will focus on two major stumbling blocks toward understanding working memory development, namely that (1) many potentially relevant aspects of the mind change in parallel during development, obscuring the role of any one change; and (2) one cannot use the same test procedure from infancy to adulthood, complicating comparisons across age groups. With regard to the first stumbling block, the parallel development of different aspects of the mind, we discuss research in which attempts were made to hold constant some factors (knowledge, strategies, direction of attention) to investigate whether developmental differences remain. With regard to the second stumbling block, procedural differences in tests for different age groups, I suggest ways in which the results might be reconciled across procedures. I highlight the value of pursuing research that could distinguish between two different key hypotheses that emerge: that there is a developmental increase in the number of working memory slots (or in a basic resource that holds items in working memory), and that there is a developmental increase in the amount of detail that each of these slots can hold. © 2017 Elsevier Inc. All rights reserved.

  15. Metal oxide resistive random access memory based synaptic devices for brain-inspired computing

    Science.gov (United States)

    Gao, Bin; Kang, Jinfeng; Zhou, Zheng; Chen, Zhe; Huang, Peng; Liu, Lifeng; Liu, Xiaoyan

    2016-04-01

    The traditional Boolean computing paradigm based on the von Neumann architecture is facing great challenges for future information technology applications such as big data, the Internet of Things (IoT), and wearable devices, due to the limited processing capability issues such as binary data storage and computing, non-parallel data processing, and the buses requirement between memory units and logic units. The brain-inspired neuromorphic computing paradigm is believed to be one of the promising solutions for realizing more complex functions with a lower cost. To perform such brain-inspired computing with a low cost and low power consumption, novel devices for use as electronic synapses are needed. Metal oxide resistive random access memory (ReRAM) devices have emerged as the leading candidate for electronic synapses. This paper comprehensively addresses the recent work on the design and optimization of metal oxide ReRAM-based synaptic devices. A performance enhancement methodology and optimized operation scheme to achieve analog resistive switching and low-energy training behavior are provided. A three-dimensional vertical synapse network architecture is proposed for high-density integration and low-cost fabrication. The impacts of the ReRAM synaptic device features on the performances of neuromorphic systems are also discussed on the basis of a constructed neuromorphic visual system with a pattern recognition function. Possible solutions to achieve the high recognition accuracy and efficiency of neuromorphic systems are presented.

  16. Energy Scaling Advantages of Resistive Memory Crossbar Based Computation and its Application to Sparse Coding

    Directory of Open Access Journals (Sweden)

    Sapan eAgarwal

    2016-01-01

    Full Text Available The exponential increase in data over the last decade presents a significant challenge to analytics efforts that seek to process and interpret such data for various applications. Neural-inspired computing approaches are being developed in order to leverage the computational advantages of the analog, low-power data processing observed in biological systems. Analog resistive memory crossbars can perform a parallel read or a vector-matrix multiplication as well as a parallel write or a rank-1 update with high computational efficiency. For an NxN crossbar, these two kernels are at a minimum O(N more energy efficient than a digital memory-based architecture. If the read operation is noise limited, the energy to read a column can be independent of the crossbar size (O(1. These two kernels form the basis of many neuromorphic algorithms such as image, text, and speech recognition. For instance, these kernels can be applied to a neural sparse coding algorithm to give an O(N reduction in energy for the entire algorithm. Sparse coding is a rich problem with a host of applications including computer vision, object tracking, and more generally unsupervised learning.

  17. The role of working memory on measuring mental models of physical systems

    Directory of Open Access Journals (Sweden)

    José F. Quesada

    2001-01-01

    Full Text Available El papel de la Memoria Operativa en la medición de los modelos mentales de los sistemas físicos. Hasta ahora no ha existido un acuerdo sobre la definición correcta de Modelo Mental de un sistema físico y sobre la forma como podemos inferir el Modelo Mental que una persona tiene del sistema con el que está interactuando. En este artículo se describe una investigación encaminada a solucionar estos problemas con la propuesta de una definición según la cual un Modelos Mental es una representación dinámica creada en la Memoria Operativa, combinando la información almacenada en la Memoria a Largo Plazo y las características extraídas del ambiente. Las hipótesis derivadas de esta propuesta se prueban en tres experimentos y se discuten las implicaciones que sus resultados tienen para la investigación futura sobre Modelos Mentales.

  18. Soft-error tolerance and energy consumption evaluation of embedded computer with magnetic random access memory in practical systems using computer simulations

    Science.gov (United States)

    Nebashi, Ryusuke; Sakimura, Noboru; Sugibayashi, Tadahiko

    2017-08-01

    We evaluated the soft-error tolerance and energy consumption of an embedded computer with magnetic random access memory (MRAM) using two computer simulators. One is a central processing unit (CPU) simulator of a typical embedded computer system. We simulated the radiation-induced single-event-upset (SEU) probability in a spin-transfer-torque MRAM cell and also the failure rate of a typical embedded computer due to its main memory SEU error. The other is a delay tolerant network (DTN) system simulator. It simulates the power dissipation of wireless sensor network nodes of the system using a revised CPU simulator and a network simulator. We demonstrated that the SEU effect on the embedded computer with 1 Gbit MRAM-based working memory is less than 1 failure in time (FIT). We also demonstrated that the energy consumption of the DTN sensor node with MRAM-based working memory can be reduced to 1/11. These results indicate that MRAM-based working memory enhances the disaster tolerance of embedded computers.

  19. Logic computation in phase change materials by threshold and memory switching.

    Science.gov (United States)

    Cassinerio, M; Ciocchini, N; Ielmini, D

    2013-11-06

    Memristors, namely hysteretic devices capable of changing their resistance in response to applied electrical stimuli, may provide new opportunities for future memory and computation, thanks to their scalable size, low switching energy and nonvolatile nature. We have developed a functionally complete set of logic functions including NOR, NAND and NOT gates, each utilizing a single phase-change memristor (PCM) where resistance switching is due to the phase transformation of an active chalcogenide material. The logic operations are enabled by the high functionality of nanoscale phase change, featuring voltage comparison, additive crystallization and pulse-induced amorphization. The nonvolatile nature of memristive states provides the basis for developing reconfigurable hybrid logic/memory circuits featuring low-power and high-speed switching. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Studies of electron collisions with polyatomic molecules using distributed-memory parallel computers

    International Nuclear Information System (INIS)

    Winstead, C.; Hipes, P.G.; Lima, M.A.P.; McKoy, V.

    1991-01-01

    Elastic electron scattering cross sections from 5--30 eV are reported for the molecules C 2 H 4 , C 2 H 6 , C 3 H 8 , Si 2 H 6 , and GeH 4 , obtained using an implementation of the Schwinger multichannel method for distributed-memory parallel computer architectures. These results, obtained within the static-exchange approximation, are in generally good agreement with the available experimental data. These calculations demonstrate the potential of highly parallel computation in the study of collisions between low-energy electrons and polyatomic gases. The computational methodology discussed is also directly applicable to the calculation of elastic cross sections at higher levels of approximation (target polarization) and of electronic excitation cross sections

  1. Computational cost of isogeometric multi-frontal solvers on parallel distributed memory machines

    KAUST Repository

    Woźniak, Maciej

    2015-02-01

    This paper derives theoretical estimates of the computational cost for isogeometric multi-frontal direct solver executed on parallel distributed memory machines. We show theoretically that for the Cp-1 global continuity of the isogeometric solution, both the computational cost and the communication cost of a direct solver are of order O(log(N)p2) for the one dimensional (1D) case, O(Np2) for the two dimensional (2D) case, and O(N4/3p2) for the three dimensional (3D) case, where N is the number of degrees of freedom and p is the polynomial order of the B-spline basis functions. The theoretical estimates are verified by numerical experiments performed with three parallel multi-frontal direct solvers: MUMPS, PaStiX and SuperLU, available through PETIGA toolkit built on top of PETSc. Numerical results confirm these theoretical estimates both in terms of p and N. For a given problem size, the strong efficiency rapidly decreases as the number of processors increases, becoming about 20% for 256 processors for a 3D example with 1283 unknowns and linear B-splines with C0 global continuity, and 15% for a 3D example with 643 unknowns and quartic B-splines with C3 global continuity. At the same time, one cannot arbitrarily increase the problem size, since the memory required by higher order continuity spaces is large, quickly consuming all the available memory resources even in the parallel distributed memory version. Numerical results also suggest that the use of distributed parallel machines is highly beneficial when solving higher order continuity spaces, although the number of processors that one can efficiently employ is somehow limited.

  2. Recent onmiddellijk geheugenonderzoek bij zwakzinnigen [Investigation of short term memory in mentally retarded subjects

    NARCIS (Netherlands)

    Bunt, A.A.

    1975-01-01

    The aim of this literature review is to get a preliminary answer to the problem of the type of information processing deficit of undifferentiated retardates (with an IQ of about 70). Taking the topic of verbal short-term memory as a framework, it appears that children or adults of a subnormal

  3. Short-Term Memory for Movement Duration in Mentally Retarded and Nonretarded Adults.

    Science.gov (United States)

    Elliott, Digby; Grundy, Stephen B.

    1984-01-01

    Both retarded and nonretarded adults (N=26) failed to benefit from opportunities to mentally rehearse their criterion movement over the retention interval, suggesting that strategic differences between the groups cannot explain the poorer performances of the retarded Ss. The retarded Ss appeared to have problems remembering the sensory…

  4. Adolescent over-general memory, life events and mental health outcomes: Findings from a UK cohort study.

    Science.gov (United States)

    Crane, Catherine; Heron, Jon; Gunnell, David; Lewis, Glyn; Evans, Jonathan; Williams, J Mark G

    2016-01-01

    Previous research suggesting that over-general memory (OGM) may moderate the effect of life events on depressive symptoms and suicidality has sampled older adolescents or adults, or younger adolescents in high-risk populations, and has been conducted over relatively short follow-up periods. The authors examined the relationship between OGM at age 13 and life events and mental health outcomes (depression, self-harm, suicidal ideation and planning) at age 16 years within a sample of 5792 adolescents participating in the Avon Longitudinal Study of Parents and Children (ALSPAC), approximately 3800 of whom had also provided data on depression and self-harm. There was no clear evidence of either direct or interactive effects of OGM at age 13 on levels of depression at age 16. Similarly there was no clear evidence of either direct or interactive effects of OGM on suicidal ideation and self-harm. Although there was some evidence that over-general autobiographical memory was associated with reduced risk of suicidal planning and increased risk of self-harm, these associations were absent when confounding variables were taken into account. The findings imply that although OGM is a marker of vulnerability to depression and related psychopathology in high-risk groups, this cannot be assumed to generalise to whole populations.

  5. The role of visual and spatial working memory in forming mental models derived from survey and route descriptions.

    Science.gov (United States)

    Meneghetti, Chiara; Labate, Enia; Pazzaglia, Francesca; Hamilton, Colin; Gyselinck, Valérie

    2017-05-01

    This study examines the involvement of spatial and visual working memory (WM) in the construction of flexible spatial models derived from survey and route descriptions. Sixty young adults listened to environment descriptions, 30 from a survey perspective and the other 30 from a route perspective, while they performed spatial (spatial tapping [ST]) and visual (dynamic visual noise [DVN]) secondary tasks - believed to overload the spatial and visual working memory (WM) components, respectively - or no secondary task (control, C). Their mental representations of the environment were tested by free recall and a verification test with both route and survey statements. Results showed that, for both recall tasks, accuracy was worse in the ST than in the C or DVN conditions. In the verification test, the effect of both ST and DVN was a decreasing accuracy for sentences testing spatial relations from the opposite perspective to the one learnt than if the perspective was the same; only ST had a stronger interference effect than the C condition for sentences from the opposite perspective from the one learnt. Overall, these findings indicate that both visual and spatial WM, and especially the latter, are involved in the construction of perspective-flexible spatial models. © 2016 The British Psychological Society.

  6. Iterative schemes for parallel Sn algorithms in a shared-memory computing environment

    International Nuclear Information System (INIS)

    Haghighat, A.; Hunter, M.A.; Mattis, R.E.

    1995-01-01

    Several two-dimensional spatial domain partitioning S n transport theory algorithms are developed on the basis of different iterative schemes. These algorithms are incorporated into TWOTRAN-II and tested on the shared-memory CRAY Y-MP C90 computer. For a series of fixed-source r-z geometry homogeneous problems, it is demonstrated that the concurrent red-black algorithms may result in large parallel efficiencies (>60%) on C90. It is also demonstrated that for a realistic shielding problem, the use of the negative flux fixup causes high load imbalance, which results in a significant loss of parallel efficiency

  7. Disentangling the Relationship Between the Adoption of In-Memory Computing and Firm Performance

    DEFF Research Database (Denmark)

    Fay, Marua; Müller, Oliver; vom Brocke, Jan

    2016-01-01

    Recent growth in data volume, variety, and velocity led to an increased demand for high-performance data processing and analytics solutions. In-memory computing (IMC) enables organizations to boost their information processing capacity, and is widely acknowledged to be one of the leading strategic...... at explaining the relationship between the adoption of IMC solutions and firm performance. In this research-in-progress paper we discuss the theoretical background of our work, describe the proposed research design, and develop five hypotheses for later testing. Our work aims at contributing to the research...

  8. Memory

    OpenAIRE

    Wager, Nadia

    2017-01-01

    This chapter will explore a response to traumatic victimisation which has divided the opinions of psychologists at an exponential rate. We will be examining amnesia for memories of childhood sexual abuse and the potential to recover these memories in adulthood. Whilst this phenomenon is generally accepted in clinical circles, it is seen as highly contentious amongst research psychologists, particularly experimental cognitive psychologists. The chapter will begin with a real case study of a wo...

  9. Accessing the mental space - Spatial working memory processes for language and vision overlap in precuneus

    DEFF Research Database (Denmark)

    Wallentin, Mikkel; Weed, Ethan; Østergaard, Leif

    2008-01-01

    , strikingly overlapping a network previously shown to be involved in recall of spatial aspects of images depicting similar scenarios. This supports a neurocognitive model of language function, where sentences establish meaning by interacting with the perceptual and working memory networks of the brain.......Abstract: The ‘‘overlapping systems'' theory of language function argues that linguistic meaning construction crucially relies on contextual information provided by ‘‘nonlinguistic'' cognitive systems, such as perception and memory. This study examines whether linguistic processing of spatial.......g., ‘‘Was he turned towards her?'') and equally concrete nonspatial content (e.g., ‘‘Was he older than her?''). We found that recall of the spatial content relative to the nonspatial content resulted in higher BOLD response in a dorsoposterior network of brain regions, most significantly in precuneus...

  10. Mental hoop diaries: emotional memories of a college basketball game in rival fans.

    Science.gov (United States)

    Botzung, Anne; Rubin, David C; Miles, Amanda; Cabeza, Roberto; Labar, Kevin S

    2010-02-10

    The rivalry between the men's basketball teams of Duke University and the University of North Carolina-Chapel Hill (UNC) is one of the most storied traditions in college sports. A subculture of students at each university form social bonds with fellow fans, develop expertise in college basketball rules, team statistics, and individual players, and self-identify as a member of a fan group. The present study capitalized on the high personal investment of these fans and the strong affective tenor of a Duke-UNC basketball game to examine the neural correlates of emotional memory retrieval for a complex sporting event. Male fans watched a competitive, archived game in a social setting. During a subsequent functional magnetic resonance imaging session, participants viewed video clips depicting individual plays of the game that ended with the ball being released toward the basket. For each play, participants recalled whether or not the shot went into the basket. Hemodynamic signal changes time locked to correct memory decisions were analyzed as a function of emotional intensity and valence, according to the fan's perspective. Results showed intensity-modulated retrieval activity in midline cortical structures, sensorimotor cortex, the striatum, and the medial temporal lobe, including the amygdala. Positively valent memories specifically recruited processing in dorsal frontoparietal regions, and additional activity in the insula and medial temporal lobe for positively valent shots recalled with high confidence. This novel paradigm reveals how brain regions implicated in emotion, memory retrieval, visuomotor imagery, and social cognition contribute to the recollection of specific plays in the mind of a sports fan.

  11. SiGe epitaxial memory for neuromorphic computing with reproducible high performance based on engineered dislocations

    Science.gov (United States)

    Choi, Shinhyun; Tan, Scott H.; Li, Zefan; Kim, Yunjo; Choi, Chanyeol; Chen, Pai-Yu; Yeon, Hanwool; Yu, Shimeng; Kim, Jeehwan

    2018-01-01

    Although several types of architecture combining memory cells and transistors have been used to demonstrate artificial synaptic arrays, they usually present limited scalability and high power consumption. Transistor-free analog switching devices may overcome these limitations, yet the typical switching process they rely on—formation of filaments in an amorphous medium—is not easily controlled and hence hampers the spatial and temporal reproducibility of the performance. Here, we demonstrate analog resistive switching devices that possess desired characteristics for neuromorphic computing networks with minimal performance variations using a single-crystalline SiGe layer epitaxially grown on Si as a switching medium. Such epitaxial random access memories utilize threading dislocations in SiGe to confine metal filaments in a defined, one-dimensional channel. This confinement results in drastically enhanced switching uniformity and long retention/high endurance with a high analog on/off ratio. Simulations using the MNIST handwritten recognition data set prove that epitaxial random access memories can operate with an online learning accuracy of 95.1%.

  12. Results from the First Two Flights of the Static Computer Memory Integrity Testing Experiment

    Science.gov (United States)

    Hancock, Thomas M., III

    1999-01-01

    This paper details the scientific objectives, experiment design, data collection method, and post flight analysis following the first two flights of the Static Computer Memory Integrity Testing (SCMIT) experiment. SCMIT is designed to detect soft-event upsets in passive magnetic memory. A soft-event upset is a change in the logic state of active or passive forms of magnetic memory, commonly referred to as a "Bitflip". In its mildest form a soft-event upset can cause software exceptions, unexpected events, start spacecraft safeing (ending data collection) or corrupted fault protection and error recovery capabilities. In it's most severe form loss of mission or spacecraft can occur. Analysis after the first flight (in 1991 during STS-40) identified possible soft-event upsets to 25% of the experiment detectors. Post flight analysis after the second flight (in 1997 on STS-87) failed to find any evidence of soft-event upsets. The SCMIT experiment is currently scheduled for a third flight in December 1999 on STS-101.

  13. Modified stretched exponential model of computer system resources management limitations-The case of cache memory

    Science.gov (United States)

    Strzałka, Dominik; Dymora, Paweł; Mazurek, Mirosław

    2018-02-01

    In this paper we present some preliminary results in the field of computer systems management with relation to Tsallis thermostatistics and the ubiquitous problem of hardware limited resources. In the case of systems with non-deterministic behaviour, management of their resources is a key point that guarantees theirs acceptable performance and proper working. This is very wide problem that stands for many challenges in financial, transport, water and food, health, etc. areas. We focus on computer systems with attention paid to cache memory and propose to use an analytical model that is able to connect non-extensive entropy formalism, long-range dependencies, management of system resources and queuing theory. Obtained analytical results are related to the practical experiment showing interesting and valuable results.

  14. Raster Scan Computer Image Generation (CIG) System Based On Refresh Memory

    Science.gov (United States)

    Dichter, W.; Doris, K.; Conkling, C.

    1982-06-01

    A full color, Computer Image Generation (CIG) raster visual system has been developed which provides a high level of training sophistication by utilizing advanced semiconductor technology and innovative hardware and firmware techniques. Double buffered refresh memory and efficient algorithms eliminate the problem of conventional raster line ordering by allowing the generated image to be stored in a random fashion. Modular design techniques and simplified architecture provide significant advantages in reduced system cost, standardization of parts, and high reliability. The major system components are a general purpose computer to perform interfacing and data base functions; a geometric processor to define the instantaneous scene image; a display generator to convert the image to a video signal; an illumination control unit which provides final image processing; and a CRT monitor for display of the completed image. Additional optional enhancements include texture generators, increased edge and occultation capability, curved surface shading, and data base extensions.

  15. Photon echo quantum random access memory integration in a quantum computer

    International Nuclear Information System (INIS)

    Moiseev, Sergey A; Andrianov, Sergey N

    2012-01-01

    We have analysed an efficient integration of multi-qubit echo quantum memory (QM) into the quantum computer scheme based on squids, quantum dots or atomic resonant ensembles in a quantum electrodynamics cavity. Here, one atomic ensemble with controllable inhomogeneous broadening is used for the QM node and other nodes characterized by the homogeneously broadened resonant line are used for processing. We have found the optimal conditions for the efficient integration of the multi-qubit QM modified for the analysed scheme, and we have determined the self-temporal modes providing a perfect reversible transfer of the photon qubits between the QM node and arbitrary processing nodes. The obtained results open the way for realization of a full-scale solid state quantum computing based on the efficient multi-qubit QM. (paper)

  16. A multiprocessor computer simulation model employing a feedback scheduler/allocator for memory space and bandwidth matching and TMR processing

    Science.gov (United States)

    Bradley, D. B.; Irwin, J. D.

    1974-01-01

    A computer simulation model for a multiprocessor computer is developed that is useful for studying the problem of matching multiprocessor's memory space, memory bandwidth and numbers and speeds of processors with aggregate job set characteristics. The model assumes an input work load of a set of recurrent jobs. The model includes a feedback scheduler/allocator which attempts to improve system performance through higher memory bandwidth utilization by matching individual job requirements for space and bandwidth with space availability and estimates of bandwidth availability at the times of memory allocation. The simulation model includes provisions for specifying precedence relations among the jobs in a job set, and provisions for specifying precedence execution of TMR (Triple Modular Redundant and SIMPLEX (non redundant) jobs.

  17. The magical number 4 in short-term memory: a reconsideration of mental storage capacity.

    Science.gov (United States)

    Cowan, N

    2001-02-01

    Miller (1956) summarized evidence that people can remember about seven chunks in short-term memory (STM) tasks. However, that number was meant more as a rough estimate and a rhetorical device than as a real capacity limit. Others have since suggested that there is a more precise capacity limit, but that it is only three to five chunks. The present target article brings together a wide variety of data on capacity limits suggesting that the smaller capacity limit is real. Capacity limits will be useful in analyses of information processing only if the boundary conditions for observing them can be carefully described. Four basic conditions in which chunks can be identified and capacity limits can accordingly be observed are: (1) when information overload limits chunks to individual stimulus items, (2) when other steps are taken specifically to block the recording of stimulus items into larger chunks, (3) in performance discontinuities caused by the capacity limit, and (4) in various indirect effects of the capacity limit. Under these conditions, rehearsal and long-term memory cannot be used to combine stimulus items into chunks of an unknown size; nor can storage mechanisms that are not capacity-limited, such as sensory memory, allow the capacity-limited storage mechanism to be refilled during recall. A single, central capacity limit averaging about four chunks is implicated along with other, noncapacity-limited sources. The pure STM capacity limit expressed in chunks is distinguished from compound STM limits obtained when the number of separately held chunks is unclear. Reasons why pure capacity estimates fall within a narrow range are discussed and a capacity limit for the focus of attention is proposed.

  18. Linking Working Memory and Long-Term Memory: A Computational Model of the Learning of New Words

    Science.gov (United States)

    Jones, Gary; Gobet, Fernand; Pine, Julian M.

    2007-01-01

    The nonword repetition (NWR) test has been shown to be a good predictor of children's vocabulary size. NWR performance has been explained using phonological working memory, which is seen as a critical component in the learning of new words. However, no detailed specification of the link between phonological working memory and long-term memory…

  19. The relationship between playing computer or video games with mental health and social relationships among students in guidance schools, Kermanshah.

    Science.gov (United States)

    Reshadat, S; Ghasemi, S R; Ahmadian, M; RajabiGilan, N

    2014-01-09

    Computer or video games are a popular recreational activity and playing them may constitute a large part of leisure time. This cross-sectional study aimed to evaluate the relationship between playing computer or video games with mental health and social relationships among students in guidance schools in Kermanshah, Islamic Republic of Iran, in 2012. Our total sample was 573 students and our tool was the General Health Questionnaire (GHQ-28) and social relationships questionnaires. Survey respondents reported spending an average of 71.07 (SD 72.1) min/day on computer or video games. There was a significant relationship between time spent playing games and general mental health (P computer or video games with social relationships and their subscales, including trans-local relationships (P games (P < 0.02) and its dimensions, except for family relationships.

  20. Association between playing computer games and mental and social health among male adolescents in Iran in 2014

    Directory of Open Access Journals (Sweden)

    Mehrnoosh Mohammadi

    2016-01-01

    Full Text Available Background: As adolescents spend much time on playing computer games, their mental and social effects should be considered. The present study aimed to investigate the association between playing computer games and the mental and social health among male adolescents in Iran in 2014. Materials and Methods: This is a cross-sectional study conducted on 210 adolescents selected by multi-stage random sampling. Data were collected by Goldberg and Hillier general health (28 items and Kiez social health questionnaires. The association was tested by Pearson and Spearman correlation coefficients, one-way analysis of variance (ANOVA, and independent t-test. Computer games related factors such as the location, type, length, the adopted device, and mode of playing games were investigated. Results: Results showed that 58.9% of the subjects played games on a computer alone for 1 h at home. Results also revealed that the subjects had appropriate mental health and 83.2% had moderate social health. Results showed a poor significant association between the length of games and social health (r = −0.15, P = 0.03, the type of games and mental health (r = −0.16, P = 0.01, and the device used in playing games and social health (F = 0.95, P = 0.03. Conclusions: The findings showed that adolescents′ mental and social health is negatively associated with their playing computer games. Therefore, to promote their health, educating them about the correct way of playing computer games is essential and their parents and school authorities, including nurses working at schools, should determine its relevant factors such as the type, length, and device used in playing such games.

  1. Association between playing computer games and mental and social health among male adolescents in Iran in 2014.

    Science.gov (United States)

    Mohammadi, Mehrnoosh; RezaeiDehaghani, Abdollah; Mehrabi, Tayebeh; RezaeiDehaghani, Ali

    2016-01-01

    As adolescents spend much time on playing computer games, their mental and social effects should be considered. The present study aimed to investigate the association between playing computer games and the mental and social health among male adolescents in Iran in 2014. This is a cross-sectional study conducted on 210 adolescents selected by multi-stage random sampling. Data were collected by Goldberg and Hillier general health (28 items) and Kiez social health questionnaires. The association was tested by Pearson and Spearman correlation coefficients, one-way analysis of variance (ANOVA), and independent t-test. Computer games related factors such as the location, type, length, the adopted device, and mode of playing games were investigated. Results showed that 58.9% of the subjects played games on a computer alone for 1 h at home. Results also revealed that the subjects had appropriate mental health and 83.2% had moderate social health. Results showed a poor significant association between the length of games and social health (r = -0.15, P = 0.03), the type of games and mental health (r = -0.16, P = 0.01), and the device used in playing games and social health (F = 0.95, P = 0.03). The findings showed that adolescents' mental and social health is negatively associated with their playing computer games. Therefore, to promote their health, educating them about the correct way of playing computer games is essential and their parents and school authorities, including nurses working at schools, should determine its relevant factors such as the type, length, and device used in playing such games.

  2. Association between playing computer games and mental and social health among male adolescents in Iran in 2014

    Science.gov (United States)

    Mohammadi, Mehrnoosh; RezaeiDehaghani, Abdollah; Mehrabi, Tayebeh; RezaeiDehaghani, Ali

    2016-01-01

    Background: As adolescents spend much time on playing computer games, their mental and social effects should be considered. The present study aimed to investigate the association between playing computer games and the mental and social health among male adolescents in Iran in 2014. Materials and Methods: This is a cross-sectional study conducted on 210 adolescents selected by multi-stage random sampling. Data were collected by Goldberg and Hillier general health (28 items) and Kiez social health questionnaires. The association was tested by Pearson and Spearman correlation coefficients, one-way analysis of variance (ANOVA), and independent t-test. Computer games related factors such as the location, type, length, the adopted device, and mode of playing games were investigated. Results: Results showed that 58.9% of the subjects played games on a computer alone for 1 h at home. Results also revealed that the subjects had appropriate mental health and 83.2% had moderate social health. Results showed a poor significant association between the length of games and social health (r = −0.15, P = 0.03), the type of games and mental health (r = −0.16, P = 0.01), and the device used in playing games and social health (F = 0.95, P = 0.03). Conclusions: The findings showed that adolescents’ mental and social health is negatively associated with their playing computer games. Therefore, to promote their health, educating them about the correct way of playing computer games is essential and their parents and school authorities, including nurses working at schools, should determine its relevant factors such as the type, length, and device used in playing such games. PMID:27095988

  3. Exploring methodological frameworks for a mental task-based near-infrared spectroscopy brain-computer interface.

    Science.gov (United States)

    Weyand, Sabine; Takehara-Nishiuchi, Kaori; Chau, Tom

    2015-10-30

    Near-infrared spectroscopy (NIRS) brain-computer interfaces (BCIs) enable users to interact with their environment using only cognitive activities. This paper presents the results of a comparison of four methodological frameworks used to select a pair of tasks to control a binary NIRS-BCI; specifically, three novel personalized task paradigms and the state-of-the-art prescribed task framework were explored. Three types of personalized task selection approaches were compared, including: user-selected mental tasks using weighted slope scores (WS-scores), user-selected mental tasks using pair-wise accuracy rankings (PWAR), and researcher-selected mental tasks using PWAR. These paradigms, along with the state-of-the-art prescribed mental task framework, where mental tasks are selected based on the most commonly used tasks in literature, were tested by ten able-bodied participants who took part in five NIRS-BCI sessions. The frameworks were compared in terms of their accuracy, perceived ease-of-use, computational time, user preference, and length of training. Most notably, researcher-selected personalized tasks resulted in significantly higher accuracies, while user-selected personalized tasks resulted in significantly higher perceived ease-of-use. It was also concluded that PWAR minimized the amount of data that needed to be collected; while, WS-scores maximized user satisfaction and minimized computational time. In comparison to the state-of-the-art prescribed mental tasks, our findings show that overall, personalized tasks appear to be superior to prescribed tasks with respect to accuracy and perceived ease-of-use. The deployment of personalized rather than prescribed mental tasks ought to be considered and further investigated in future NIRS-BCI studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Accessing the mental space-Spatial working memory processes for language and vision overlap in precuneus.

    Science.gov (United States)

    Wallentin, Mikkel; Weed, Ethan; Østergaard, Leif; Mouridsen, Kim; Roepstorff, Andreas

    2008-05-01

    The "overlapping systems" theory of language function argues that linguistic meaning construction crucially relies on contextual information provided by "nonlinguistic" cognitive systems, such as perception and memory. This study examines whether linguistic processing of spatial relations established by reading sentences call on the same posterior parietal neural system involved in processing spatial relations set up through visual input. Subjects read simple sentences, which presented two agents in relation to each other, and were subsequently asked to evaluate spatial (e.g., "Was he turned towards her?") and equally concrete nonspatial content (e.g., "Was he older than her?"). We found that recall of the spatial content relative to the nonspatial content resulted in higher BOLD response in a dorsoposterior network of brain regions, most significantly in precuneus, strikingly overlapping a network previously shown to be involved in recall of spatial aspects of images depicting similar scenarios. This supports a neurocognitive model of language function, where sentences establish meaning by interacting with the perceptual and working memory networks of the brain. (Copyright) 2006 Wiley-Liss, Inc.

  5. ERP Measures of Math Anxiety: How Math Anxiety Affects Working Memory and Mental Calculation Tasks?

    Directory of Open Access Journals (Sweden)

    Manousos A. Klados

    2015-10-01

    Full Text Available There have been several attempts to account for the impact of Mathematical Anxiety (MA on brain activity with variable results. The present study examines the effects of MA on ERP amplitude during performance of simple arithmetic calculations and working memory tasks. Data were obtained from 32 university students as they solved four types of arithmetic problems (one- and two-digit addition and multiplication and a working memory task comprised of three levels of difficulty (1,2,and 3-back task. Compared to the Low-MA group, High-MA individuals demonstrated reduced ERP amplitude at frontocentral (between 180-320 ms and centroparietal locations (between 380-420 ms. These effects were independent of task difficulty/complexity, individual performance, and general state/trait anxiety levels. Results support the hypothesis that higher levels of self-reported MA are associated with lower cortical activation during the early stages of the processing of numeric stimuli in the context of cognitive tasks.

  6. The EEG as an index of neuromodulator balance in memory and mental illness

    Directory of Open Access Journals (Sweden)

    Costa eVakalopoulos

    2014-04-01

    Full Text Available There is a strong correlation between signature EEG frequency patterns and the relative levels of distinct neuromodulators. These associations become particularly evident during the sleep-wake cycle. The monoamine-acetylcholine balance hypothesis is a theory of neurophysiological markers of the EEG and a detailed description of the findings that support this proposal are presented in this paper. According to this model alpha rhythm reflects the relative predominance of cholinergic muscarinic signals and delta rhythm that of monoaminergic receptor effects. Both high voltage synchronized rhythms are likely mediated by inhibitory Gαi/o-mediated transduction of inhibitory interneurons. Cognitively, alpha and delta EEG measures are proposed to indicate automatic and flexible strategies, respectively. Sleep is associated with marked changes in relative neuromodulator levels corresponding to EEG markers of distinct stages. Sleep studies on memory consolidation present some of the strongest evidence yet for the respective roles of monoaminergic and cholinergic projections in declarative and non-declarative memory processes, a key theoretical premise for understanding the data. Affective dysregulation is reflected in altered EEG patterns during sleep.

  7. The EEG as an index of neuromodulator balance in memory and mental illness.

    Science.gov (United States)

    Vakalopoulos, Costa

    2014-01-01

    There is a strong correlation between signature EEG frequency patterns and the relative levels of distinct neuromodulators. These associations become particularly evident during the sleep-wake cycle. The monoamine-acetylcholine balance hypothesis is a theory of neurophysiological markers of the EEG and a detailed description of the findings that support this proposal are presented in this paper. According to this model alpha rhythm reflects the relative predominance of cholinergic muscarinic signals and delta rhythm that of monoaminergic receptor effects. Both high voltage synchronized rhythms are likely mediated by inhibitory Gαi/o-mediated transduction of inhibitory interneurons. Cognitively, alpha and delta EEG measures are proposed to indicate automatic and flexible strategies, respectively. Sleep is associated with marked changes in relative neuromodulator levels corresponding to EEG markers of distinct stages. Sleep studies on memory consolidation present some of the strongest evidence yet for the respective roles of monoaminergic and cholinergic projections in declarative and non-declarative memory processes, a key theoretical premise for understanding the data. Affective dysregulation is reflected in altered EEG patterns during sleep.

  8. Read-only-memory-based quantum computation: Experimental explorations using nuclear magnetic resonance and future prospects

    International Nuclear Information System (INIS)

    Sypher, D.R.; Brereton, I.M.; Wiseman, H.M.; Hollis, B.L.; Travaglione, B.C.

    2002-01-01

    Read-only-memory-based (ROM-based) quantum computation (QC) is an alternative to oracle-based QC. It has the advantages of being less 'magical', and being more suited to implementing space-efficient computation (i.e., computation using the minimum number of writable qubits). Here we consider a number of small (one- and two-qubit) quantum algorithms illustrating different aspects of ROM-based QC. They are: (a) a one-qubit algorithm to solve the Deutsch problem; (b) a one-qubit binary multiplication algorithm; (c) a two-qubit controlled binary multiplication algorithm; and (d) a two-qubit ROM-based version of the Deutsch-Jozsa algorithm. For each algorithm we present experimental verification using nuclear magnetic resonance ensemble QC. The average fidelities for the implementation were in the ranges 0.9-0.97 for the one-qubit algorithms, and 0.84-0.94 for the two-qubit algorithms. We conclude with a discussion of future prospects for ROM-based quantum computation. We propose a four-qubit algorithm, using Grover's iterate, for solving a miniature 'real-world' problem relating to the lengths of paths in a network

  9. ClimateSpark: An in-memory distributed computing framework for big climate data analytics

    Science.gov (United States)

    Hu, Fei; Yang, Chaowei; Schnase, John L.; Duffy, Daniel Q.; Xu, Mengchao; Bowen, Michael K.; Lee, Tsengdar; Song, Weiwei

    2018-06-01

    The unprecedented growth of climate data creates new opportunities for climate studies, and yet big climate data pose a grand challenge to climatologists to efficiently manage and analyze big data. The complexity of climate data content and analytical algorithms increases the difficulty of implementing algorithms on high performance computing systems. This paper proposes an in-memory, distributed computing framework, ClimateSpark, to facilitate complex big data analytics and time-consuming computational tasks. Chunking data structure improves parallel I/O efficiency, while a spatiotemporal index is built for the chunks to avoid unnecessary data reading and preprocessing. An integrated, multi-dimensional, array-based data model (ClimateRDD) and ETL operations are developed to address big climate data variety by integrating the processing components of the climate data lifecycle. ClimateSpark utilizes Spark SQL and Apache Zeppelin to develop a web portal to facilitate the interaction among climatologists, climate data, analytic operations and computing resources (e.g., using SQL query and Scala/Python notebook). Experimental results show that ClimateSpark conducts different spatiotemporal data queries/analytics with high efficiency and data locality. ClimateSpark is easily adaptable to other big multiple-dimensional, array-based datasets in various geoscience domains.

  10. Influence of the fragile X mental retardation (FMR1) gene on the brain and working memory in men with normal FMR1 alleles

    OpenAIRE

    Wang, Jun Yi; Hessl, David; Iwahashi, Christine; Cheung, Katherine; Schneider, Andrea; Hagerman, Randi J.; Hagerman, Paul J.; Rivera, Susan M.

    2012-01-01

    The fragile X mental retardation 1 (FMR1) gene plays an important role in the development and maintenance of neuronal circuits that are essential for cognitive functioning. We explored the functional linkage(s) among lymphocytic FMR1 gene expression, brain structure, and working memory in healthy adult males. We acquired T1-weighted and diffusion tensor imaging from 34 males (18–80 years, mean ± SD = 43.6 ± 18.4 years) with normal FMR1 alleles and performed genetic and working memory assessme...

  11. Computer-Assisted Face Processing Instruction Improves Emotion Recognition, Mentalizing, and Social Skills in Students with ASD

    Science.gov (United States)

    Rice, Linda Marie; Wall, Carla Anne; Fogel, Adam; Shic, Frederick

    2015-01-01

    This study examined the extent to which a computer-based social skills intervention called "FaceSay"™ was associated with improvements in affect recognition, mentalizing, and social skills of school-aged children with Autism Spectrum Disorder (ASD). "FaceSay"™ offers students simulated practice with eye gaze, joint attention,…

  12. Memories.

    Science.gov (United States)

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  13. ClimateSpark: An In-memory Distributed Computing Framework for Big Climate Data Analytics

    Science.gov (United States)

    Hu, F.; Yang, C. P.; Duffy, D.; Schnase, J. L.; Li, Z.

    2016-12-01

    Massive array-based climate data is being generated from global surveillance systems and model simulations. They are widely used to analyze the environment problems, such as climate changes, natural hazards, and public health. However, knowing the underlying information from these big climate datasets is challenging due to both data- and computing- intensive issues in data processing and analyzing. To tackle the challenges, this paper proposes ClimateSpark, an in-memory distributed computing framework to support big climate data processing. In ClimateSpark, the spatiotemporal index is developed to enable Apache Spark to treat the array-based climate data (e.g. netCDF4, HDF4) as native formats, which are stored in Hadoop Distributed File System (HDFS) without any preprocessing. Based on the index, the spatiotemporal query services are provided to retrieve dataset according to a defined geospatial and temporal bounding box. The data subsets will be read out, and a data partition strategy will be applied to equally split the queried data to each computing node, and store them in memory as climateRDDs for processing. By leveraging Spark SQL and User Defined Function (UDFs), the climate data analysis operations can be conducted by the intuitive SQL language. ClimateSpark is evaluated by two use cases using the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA) climate reanalysis dataset. One use case is to conduct the spatiotemporal query and visualize the subset results in animation; the other one is to compare different climate model outputs using Taylor-diagram service. Experimental results show that ClimateSpark can significantly accelerate data query and processing, and enable the complex analysis services served in the SQL-style fashion.

  14. Role of working memory in transformation of visual and motor representations for use in mental simulation.

    Science.gov (United States)

    Gabbard, Carl; Lee, Jihye; Caçola, Priscila

    2013-01-01

    This study examined the role of visual working memory when transforming visual representations to motor representations in the context of motor imagery. Participants viewed randomized number sequences of three, four, and five digits, and then reproduced the sequence by finger tapping using motor imagery or actually executing the movements; movement duration was recorded. One group viewed the stimulus for three seconds and responded immediately, while the second group had a three-second view followed by a three-second blank screen delay before responding. As expected, delay group times were longer with each condition and digit load. Whereas correlations between imagined and executed actions (temporal congruency) were significant in a positive direction for both groups, interestingly, the delay group's values were significantly stronger. That outcome prompts speculation that delay influenced the congruency between motor representation and actual execution.

  15. Negative mental imagery in public speaking anxiety: Forming cognitive resistance by taxing visuospatial working memory.

    Science.gov (United States)

    Homer, Sophie R; Deeprose, Catherine; Andrade, Jackie

    2016-03-01

    This study sought to reconcile two lines of research. Previous studies have identified a prevalent and causal role of negative imagery in social phobia and public speaking anxiety; others have demonstrated that lateral eye movements during visualisation of imagery reduce its vividness, most likely by loading the visuospatial sketchpad of working memory. It was hypothesised that using eye movements to reduce the intensity of negative imagery associated with public speaking may reduce anxiety resulting from imagining a public speaking scenario compared to an auditory control task. Forty undergraduate students scoring high in anxiety on the Personal Report of Confidence as a Speaker scale took part. A semi-structured interview established an image that represented the participant's public speaking anxiety, which was then visualised during an eye movement task or a matched auditory task. Reactions to imagining a hypothetical but realistic public speaking scenario were measured. As hypothesised, representative imagery was established and reduced in vividness more effectively by the eye movement task than the auditory task. The public speaking scenario was then visualised less vividly and generated less anxiety when imagined after performing the eye movement task than after the auditory task. Self-report measures and a hypothetical scenario rather than actual public speaking were used. Replication is required in larger as well as clinical samples. Visuospatial working memory tasks may preferentially reduce anxiety associated with personal images of feared events, and thus provide cognitive resistance which reduces emotional reactions to imagined, and potentially real-life future stressful experiences. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Differences by Sex in Association of Mental Health With Video Gaming or Other Nonacademic Computer Use Among US Adolescents.

    Science.gov (United States)

    Lee, Hogan H; Sung, Jung Hye; Lee, Ji-Young; Lee, Jae Eun

    2017-11-22

    Although numerous studies have examined the association between playing video games and cognitive skills, aggression, and depression, few studies have examined how these associations differ by sex. The objective of our study was to determine differences by sex in association between video gaming or other nonacademic computer use and depressive symptoms, suicidal behavior, and being bullied among adolescents in the United States. We used data from the 2015 Youth Risk Behavior Survey on 15,624 US high school students. Rao-Scott χ 2 tests, which were adjusted for the complex sampling design, were conducted to assess differences by sex in the association of mental health with video gaming or other nonacademic computer use. Approximately one-fifth (19.4%) of adolescents spent 5 or more hours daily on video gaming or other nonacademic computer use, and 17.9% did not spend any time in those activities. A greater percentage of female adolescents than male adolescents reported spending no time (22.1% and 14.0%, respectively) or 5 hours or more (21.3% and 17.5%, respectively) in gaming and other nonacademic computer use (P gaming or other nonacademic computer use differed by sex. Among female adolescents, prevalence of mental problems increased steadily in association with increased time spent, whereas the pattern for male adolescents followed a J-shaped curve, decreasing initially, increasing slowly, and then increasing rapidly beginning at 4 hours or more. Female adolescents were more likely to have all 3 mental health problems than male adolescents were. Spending no time or 5 hours or more daily on video gaming or other nonacademic computer use was associated with increased mental problems among both sexes. As suggested by the J-shaped relationship, 1 hour or less spent on video gaming or other nonacademic computer use may reduce depressive symptoms, suicidal behavior, and being bullied compared with no use or excessive use.

  17. Reduction of Used Memory Ensemble Kalman Filtering (RumEnKF): A data assimilation scheme for memory intensive, high performance computing

    Science.gov (United States)

    Hut, Rolf; Amisigo, Barnabas A.; Steele-Dunne, Susan; van de Giesen, Nick

    2015-12-01

    Reduction of Used Memory Ensemble Kalman Filtering (RumEnKF) is introduced as a variant on the Ensemble Kalman Filter (EnKF). RumEnKF differs from EnKF in that it does not store the entire ensemble, but rather only saves the first two moments of the ensemble distribution. In this way, the number of ensemble members that can be calculated is less dependent on available memory, and mainly on available computing power (CPU). RumEnKF is developed to make optimal use of current generation super computer architecture, where the number of available floating point operations (flops) increases more rapidly than the available memory and where inter-node communication can quickly become a bottleneck. RumEnKF reduces the used memory compared to the EnKF when the number of ensemble members is greater than half the number of state variables. In this paper, three simple models are used (auto-regressive, low dimensional Lorenz and high dimensional Lorenz) to show that RumEnKF performs similarly to the EnKF. Furthermore, it is also shown that increasing the ensemble size has a similar impact on the estimation error from the three algorithms.

  18. Abnormal response to mental stress in patients with Takotsubo cardiomyopathy detected by gated single photon emission computed tomography

    International Nuclear Information System (INIS)

    Sciagra, Roberto; Genovese, Sabrina; Pupi, Alberto; Parodi, Guido; Bellandi, Benedetta; Antoniucci, David; Del Pace, Stefano; Zampini, Linda; Gensini, Gian Franco

    2010-01-01

    Persistent abnormalities are usually not detected in patients with Takotsubo cardiomyopathy (TTC). Since sympathetically mediated myocardial damage has been proposed as a causative mechanism of TTC, we explored whether mental stress could evoke abnormalities in these patients. One month after an acute event, 22 patients fulfilling all TTC diagnostic criteria and 11 controls underwent resting and mental stress gated single photon emission computed tomography (SPECT). Perfusion, wall motion, transient ischaemic dilation (TID) and left ventricular (LV) ejection fraction (EF) were evaluated. None of the controls showed stress-induced abnormalities. Mental stress evoked regional changes (perfusion defects and/or wall motion abnormality) in 16 TTC subjects and global abnormalities (LVEF fall >5% and/or TID >1.10) in 13; 3 had a completely negative response. TID, delta LVEF and delta wall motion score were significantly different in TTC vs control patients: 1.08 ± 0.20 vs 0.95 ± 0.11 (p < 0.05), -1.7 ± 6% vs 4 ± 5% (p < 0.02) and 2.5 (0, 4.25) vs 0 (0, 0) (p < 0.002), respectively. Mental stress may evoke regional and/or global abnormalities in most TTC patients. The abnormal response to mental stress supports the role of sympathetic stimulation in TTC. Mental stress could thus be helpful for TTC evaluation. (orig.)

  19. Impact of singular excessive computer game and television exposure on sleep patterns and memory performance of school-aged children.

    Science.gov (United States)

    Dworak, Markus; Schierl, Thomas; Bruns, Thomas; Strüder, Heiko Klaus

    2007-11-01

    Television and computer game consumption are a powerful influence in the lives of most children. Previous evidence has supported the notion that media exposure could impair a variety of behavioral characteristics. Excessive television viewing and computer game playing have been associated with many psychiatric symptoms, especially emotional and behavioral symptoms, somatic complaints, attention problems such as hyperactivity, and family interaction problems. Nevertheless, there is insufficient knowledge about the relationship between singular excessive media consumption on sleep patterns and linked implications on children. The aim of this study was to investigate the effects of singular excessive television and computer game consumption on sleep patterns and memory performance of children. Eleven school-aged children were recruited for this polysomnographic study. Children were exposed to voluntary excessive television and computer game consumption. In the subsequent night, polysomnographic measurements were conducted to measure sleep-architecture and sleep-continuity parameters. In addition, a visual and verbal memory test was conducted before media stimulation and after the subsequent sleeping period to determine visuospatial and verbal memory performance. Only computer game playing resulted in significant reduced amounts of slow-wave sleep as well as significant declines in verbal memory performance. Prolonged sleep-onset latency and more stage 2 sleep were also detected after previous computer game consumption. No effects on rapid eye movement sleep were observed. Television viewing reduced sleep efficiency significantly but did not affect sleep patterns. The results suggest that television and computer game exposure affect children's sleep and deteriorate verbal cognitive performance, which supports the hypothesis of the negative influence of media consumption on children's sleep, learning, and memory.

  20. A computer vision-based automated Figure-8 maze for working memory test in rodents.

    Science.gov (United States)

    Pedigo, Samuel F; Song, Eun Young; Jung, Min Whan; Kim, Jeansok J

    2006-09-30

    The benchmark test for prefrontal cortex (PFC)-mediated working memory in rodents is a delayed alternation task utilizing variations of T-maze or Figure-8 maze, which requires the animals to make specific arm entry responses for reward. In this task, however, manual procedures involved in shaping target behavior, imposing delays between trials and delivering rewards can potentially influence the animal's performance on the maze. Here, we report an automated Figure-8 maze which does not necessitate experimenter-subject interaction during shaping, training or testing. This system incorporates a computer vision system for tracking, motorized gates to impose delays, and automated reward delivery. The maze is controlled by custom software that records the animal's location and activates the gates according to the animal's behavior and a control algorithm. The program performs calculations of task accuracy, tracks movement sequence through the maze, and provides other dependent variables (such as running speed, time spent in different maze locations, activity level during delay). Testing in rats indicates that the performance accuracy is inversely proportional to the delay interval, decreases with PFC lesions, and that animals anticipate timing during long delays. Thus, our automated Figure-8 maze is effective at assessing working memory and provides novel behavioral measures in rodents.

  1. Holographic memory system based on projection recording of computer-generated 1D Fourier holograms.

    Science.gov (United States)

    Betin, A Yu; Bobrinev, V I; Donchenko, S S; Odinokov, S B; Evtikhiev, N N; Starikov, R S; Starikov, S N; Zlokazov, E Yu

    2014-10-01

    Utilization of computer generation of holographic structures significantly simplifies the optical scheme that is used to record the microholograms in a holographic memory record system. Also digital holographic synthesis allows to account the nonlinear errors of the record system to improve the microholograms quality. The multiplexed record of holograms is a widespread technique to increase the data record density. In this article we represent the holographic memory system based on digital synthesis of amplitude one-dimensional (1D) Fourier transform holograms and the multiplexed record of these holograms onto the holographic carrier using optical projection scheme. 1D Fourier transform holograms are very sensitive to orientation of the anamorphic optical element (cylindrical lens) that is required for encoded data object reconstruction. The multiplex record of several holograms with different orientation in an optical projection scheme allowed reconstruction of the data object from each hologram by rotating the cylindrical lens on the corresponding angle. Also, we discuss two optical schemes for the recorded holograms readout: a full-page readout system and line-by-line readout system. We consider the benefits of both systems and present the results of experimental modeling of 1D Fourier holograms nonmultiplex and multiplex record and reconstruction.

  2. Logic and memory concepts for all-magnetic computing based on transverse domain walls

    International Nuclear Information System (INIS)

    Vandermeulen, J; Van de Wiele, B; Dupré, L; Van Waeyenberge, B

    2015-01-01

    We introduce a non-volatile digital logic and memory concept in which the binary data is stored in the transverse magnetic domain walls present in in-plane magnetized nanowires with sufficiently small cross sectional dimensions. We assign the digital bit to the two possible orientations of the transverse domain wall. Numerical proofs-of-concept are presented for a NOT-, AND- and OR-gate, a FAN-out as well as a reading and writing device. Contrary to the chirality based vortex domain wall logic gates introduced in Omari and Hayward (2014 Phys. Rev. Appl. 2 044001), the presented concepts remain applicable when miniaturized and are driven by electrical currents, making the technology compatible with the in-plane racetrack memory concept. The individual devices can be easily combined to logic networks working with clock speeds that scale linearly with decreasing design dimensions. This opens opportunities to an all-magnetic computing technology where the digital data is stored and processed under the same magnetic representation. (paper)

  3. Computational Thermodynamics and Kinetics-Based ICME Framework for High-Temperature Shape Memory Alloys

    Science.gov (United States)

    Arróyave, Raymundo; Talapatra, Anjana; Johnson, Luke; Singh, Navdeep; Ma, Ji; Karaman, Ibrahim

    2015-11-01

    Over the last decade, considerable interest in the development of High-Temperature Shape Memory Alloys (HTSMAs) for solid-state actuation has increased dramatically as key applications in the aerospace and automotive industry demand actuation temperatures well above those of conventional SMAs. Most of the research to date has focused on establishing the (forward) connections between chemistry, processing, (micro)structure, properties, and performance. Much less work has been dedicated to the development of frameworks capable of addressing the inverse problem of establishing necessary chemistry and processing schedules to achieve specific performance goals. Integrated Computational Materials Engineering (ICME) has emerged as a powerful framework to address this problem, although it has yet to be applied to the development of HTSMAs. In this paper, the contributions of computational thermodynamics and kinetics to ICME of HTSMAs are described. Some representative examples of the use of computational thermodynamics and kinetics to understand the phase stability and microstructural evolution in HTSMAs are discussed. Some very recent efforts at combining both to assist in the design of HTSMAs and limitations to the full implementation of ICME frameworks for HTSMA development are presented.

  4. The Case for Higher Computational Density in the Memory-Bound FDTD Method within Multicore Environments

    Directory of Open Access Journals (Sweden)

    Mohammed F. Hadi

    2012-01-01

    Full Text Available It is argued here that more accurate though more compute-intensive alternate algorithms to certain computational methods which are deemed too inefficient and wasteful when implemented within serial codes can be more efficient and cost-effective when implemented in parallel codes designed to run on today's multicore and many-core environments. This argument is most germane to methods that involve large data sets with relatively limited computational density—in other words, algorithms with small ratios of floating point operations to memory accesses. The examples chosen here to support this argument represent a variety of high-order finite-difference time-domain algorithms. It will be demonstrated that a three- to eightfold increase in floating-point operations due to higher-order finite-differences will translate to only two- to threefold increases in actual run times using either graphical or central processing units of today. It is hoped that this argument will convince researchers to revisit certain numerical techniques that have long been shelved and reevaluate them for multicore usability.

  5. Common Ground for Spatial Cognition? A Behavioral and fMRI Study of Sex Differences in Mental Rotation and Spatial Working Memory

    Directory of Open Access Journals (Sweden)

    Sarah L. Levin

    2005-01-01

    Full Text Available Sex differences in spatial cognition are well documented; males typically outperform females on tasks dealing with mental rotation and spatial navigation, while females tend to outperform males on tasks dealing with object location, relational object location memory, or spatial working memory. Here we investigated both behavioral and neural sex differences in sex-specific spatial abilities. In Experiment 1, sixty-six (30 males, 36 females participants completed computerized mental rotation (MR and spatial working memory (SWM tasks. In Experiment 2, twelve (6 males, 6 females participants were given slightly modified versions of the same tasks during functional magnetic resonance imaging (fMRI. In both experiments, males outperformed females on the MR task, but no behavioral sex difference was observed on the SWM task. Males showed more activation in left parahippocampal gyrus, right medial frontal gyrus, inferior parietal lobe, inferior frontal gyrus in the MR task. Females showed activation in the left parahippocampal gyrus only. For the study condition of the spatial working memory task, females showed activation in left inferior frontal gyrus, while males activated left inferior parietal and medial frontal areas. In the test conditions, females showed activation in the right inferior frontal gyrus, left middle temporal gyrus, and left parahippocampal gyrus. Males activated right medial frontal gyrus and inferior parietal lobe. Interestingly, similar regions – parahippocampal gyrus, inferior parietal lobe, and middle temporal gyrus - were found to be active when males solved mental rotation tasks and females solved spatial working memory tasks. Further, performance was modulated by activation in the parahippocampal gyrus and middle temporal gyrus for males and the middle temporal gyrus and inferior frontal gyrus for females. These data extend previous claims for sex differences in sex specific spatial cognitive abilities by demonstrating

  6. Dizziness and progressively poor memory for one year, combined with epilepsy, mental and behavior disorder for 19 days

    Directory of Open Access Journals (Sweden)

    Kun JIANG

    2015-04-01

    Full Text Available It is well known that neurosyphilis has various brain MRI manifestations. In this report, we present a rare case with DWI lace-like high signal in cerebral cortex, which is usually seen in Creutzfeldt-Jakob disease (CJD. A 50-year-old male developed dizziness, poor memory, seizures, mental and behavioral disorders, and was admitted to our Emergency Department, where he experienced sudden left hemiplegia. Rapid plasma regain (RPR and treponema pallidum particle agglutination assay (TPPA was positive in blood and cerebrospinal fluid (CSF. CSF: 14-3-3 protein (+. Brain MRI showed high FLAIR signals in the right frontal lobe, temporal lobe, insular lobe, occipital lobe and thalamus before the treatment. As for this patient, it was difficult to differentiate CJD from neurosyphilis at first. He was given penicillin treatment and responded well. Those lesions in brain MRI decreased after treatment. This case was reported to raise the awareness of early treatment of neruosyphilis and showed a special DWI lace-like image of this disease. DOI: 10.3969/j.issn.1672-6731.2015.04.016

  7. Event parallelism: Distributed memory parallel computing for high energy physics experiments

    International Nuclear Information System (INIS)

    Nash, T.

    1989-05-01

    This paper describes the present and expected future development of distributed memory parallel computers for high energy physics experiments. It covers the use of event parallel microprocessor farms, particularly at Fermilab, including both ACP multiprocessors and farms of MicroVAXES. These systems have proven very cost effective in the past. A case is made for moving to the more open environment of UNIX and RISC processors. The 2nd Generation ACP Multiprocessor System, which is based on powerful RISC systems, is described. Given the promise of still more extraordinary increases in processor performance, a new emphasis on point to point, rather than bussed, communication will be required. Developments in this direction are described. 6 figs

  8. Simulation of radiation effects on three-dimensional computer optical memories

    International Nuclear Information System (INIS)

    Moscovitch, M.; Emfietzoglou, D.

    1997-01-01

    A model was developed to simulate the effects of heavy charged-particle (HCP) radiation on the information stored in three-dimensional computer optical memories. The model is based on (i) the HCP track radial dose distribution, (ii) the spatial and temporal distribution of temperature in the track, (iii) the matrix-specific radiation-induced changes that will affect the response, and (iv) the kinetics of transition of photochromic molecules from the colored to the colorless isomeric form (bit flip). It is shown that information stored in a volume of several nanometers radius around the particle close-quote s track axis may be lost. The magnitude of the effect is dependent on the particle close-quote s track structure. copyright 1997 American Institute of Physics

  9. Simulation of radiation effects on three-dimensional computer optical memories

    Science.gov (United States)

    Moscovitch, M.; Emfietzoglou, D.

    1997-01-01

    A model was developed to simulate the effects of heavy charged-particle (HCP) radiation on the information stored in three-dimensional computer optical memories. The model is based on (i) the HCP track radial dose distribution, (ii) the spatial and temporal distribution of temperature in the track, (iii) the matrix-specific radiation-induced changes that will affect the response, and (iv) the kinetics of transition of photochromic molecules from the colored to the colorless isomeric form (bit flip). It is shown that information stored in a volume of several nanometers radius around the particle's track axis may be lost. The magnitude of the effect is dependent on the particle's track structure.

  10. Event parallelism: Distributed memory parallel computing for high energy physics experiments

    International Nuclear Information System (INIS)

    Nash, T.

    1989-01-01

    This paper describes the present and expected future development of distributed memory parallel computers for high energy physics experiments. It covers the use of event parallel microprocessor farms, particularly at Fermilab, including both ACP multiprocessors and farms of MicroVAXES. These systems have proven very cost effective in the past. A case is made for moving to the more open environment of UNIX and RISC processors. The 2nd Generation ACP Multiprocessor System, which is based on powerful RISC systems, is described. Given the promise of still more extraordinary increases in processor performance, a new emphasis on point to point, rather than bussed, communication will be required. Developments in this direction are described. (orig.)

  11. Event parallelism: Distributed memory parallel computing for high energy physics experiments

    Science.gov (United States)

    Nash, Thomas

    1989-12-01

    This paper describes the present and expected future development of distributed memory parallel computers for high energy physics experiments. It covers the use of event parallel microprocessor farms, particularly at Fermilab, including both ACP multiprocessors and farms of MicroVAXES. These systems have proven very cost effective in the past. A case is made for moving to the more open environment of UNIX and RISC processors. The 2nd Generation ACP Multiprocessor System, which is based on powerful RISC system, is described. Given the promise of still more extraordinary increases in processor performance, a new emphasis on point to point, rather than bussed, communication will be required. Developments in this direction are described.

  12. Personality differences in mental imagery and the effects on verbal memory.

    Science.gov (United States)

    McDougall, Siné; Pfeifer, Gaby

    2012-11-01

    This study examined the effects of extraversion and neuroticism on participants' reported vividness of visual imagery and on their memory performance for concrete and abstract nouns. Groups of extraverts (n = 15) and introverts (n = 15) were selected from a larger original sample and asked to remember a series of concrete and abstract nouns, including a set of lexically ambiguous concrete homonyms (e.g., earth = 1. planet, 2. soil). Extraverts reported more vivid imagery than introverts but this did not translate into better recall for extraverts, even for concrete stimuli. Recall was best for unambiguous concrete nouns, followed by concrete homonyms, then abstract nouns. While initial analyses suggested that there was an interaction between extraversion and the type of word presented, later analyses revealed that neuroticism was the main driver in differences in recall between different word types. While differences in recall were best explained by context availability theory (Schwanenflugel, 1991) rather than dual coding theory (Paivio, 1991), questions remain about the power of either theory to explain the role of individual differences in personality on recall, particularly given that imagery vividness effects were related to extraversion while differences in recall were related to neuroticism. The implications of these findings for future research and theoretical development are discussed. ©2012 The British Psychological Society.

  13. Self-regulation of frontal-midline theta facilitates memory updating and mental set shifting

    Directory of Open Access Journals (Sweden)

    Stefanie eEnriquez-Geppert

    2014-12-01

    Full Text Available Frontal-midline (fm theta oscillations as measured via the electroencephalogram (EEG have been suggested as neural working language of executive functioning. Their power has been shown to increase when cognitive processing or task performance is enhanced. Thus, the question arises whether learning to increase fm-theta amplitudes would functionally impact the behavioral performance in tasks probing executive functions (EFs. Here, the effects of neurofeedback, a learning method to self-up-regulate fm-theta over frontal-midline electrodes, on the four most representative EFs, memory updating, set shifting, conflict monitoring, and motor inhibition are presented. Before beginning and after completing an individualized, eight-session gap-spaced neurofeedback intervention, the three-back, letter/number task-switching, Stroop, and stop-signal tasks were tested while measuring the EEG. Self-determined up-regulation of fm-theta and its putative role for executive functioning were compared to an active control group, the so-called pseudo-neurofeedback group. Task-related fm-theta activity after training differed significantly between groups. More importantly, though, after neurofeedback significantly enhanced behavioral performance was observed. The training group showed higher accuracy scores in the three-back task and reduced mixing and shifting costs in letter/number task-switching. However, this specific protocol type did not affect performance in tasks probing conflict monitoring and motor inhibition. Thus, our results suggest a modulation of proactive but not reactive mechanisms of cognitive control. In sum, the modulation of fm-theta via neurofeedback may serve as potent treatment approach for executive dysfunctions.

  14. Correlates of self-reported, autobiographical, and mini-mental status examination defined memory deficits following electroconvulsive therapy in South India.

    Science.gov (United States)

    Rajkumar, Anto P; Petit, Cheryl P; Rachana, Arun; Deinde, Funmi; Shyamsundar, G; Thangadurai, P; Jacob, Kuruthukulangara S

    2018-04-01

    Cognitive deficits, self-reported or found following electroconvulsive therapy (ECT), and their correlates are diverse. Despite the characteristics of people receiving ECT in Asia differ widely from the west, pertinent research from Asia remains sparse. We investigated the correlates of self-reported, mini-mental status examination (MMSE) defined, and autobiographical memory deficits in a cohort that received ECT in a south Indian tertiary-care setting. 76 consecutive consenting people were recruited within seven days of completing their ECT course. Memory was assessed by a subjective Likert scale, MMSE, and an autobiographical memory scale (AMS). Psychopathology was assessed by brief psychiatric rating scale, and serum cortisol levels were estimated by chemi-luminescence immunoassays. Relevant sociodemographic and clinical data were collected from the participants, and their medical records. The correlates were analysed using generalised linear models after adjusting for the effects of potential confounders. Self-reported, MMSE-defined, and autobiographical memory deficits were present in 27.6% (95%CI 17.6-37.7%), 42.1% (95%CI 31.0-53.2%), and 36.8% (95%CI 26.0-47.7%) of participants, respectively. Agreement between the memory deficits was poor. Age, less education, duration of illness, hypothyroidism, and past history of another ECT course were significantly associated with MMSE-defined deficits. Age, anaemia, past ECT course, and pre-ECT blood pressure were significantly associated with autobiographical memory deficits, while residual psychopathology and cortisol levels were significantly associated with self-reported memory deficits. Self-reported, MMSE-defined, and autobiographical memory deficits are common at the completion of ECT course, and their correlates differ. All service users receiving ECT need periodic cognitive assessments evaluating multiple cognitive domains. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Memory architecture for efficient utilization of SDRAM: a case study of the computation/memory access trade-off

    DEFF Research Database (Denmark)

    Gleerup, Thomas Møller; Holten-Lund, Hans Erik; Madsen, Jan

    2000-01-01

    . In software, forward differencing is usually better, but in this hardware implementation, the trade-off has made it possible to develop a very regular memory architecture with a buffering system, which can reach 95% bandwidth utilization using off-the-shelf SDRAM, This is achieved by changing the algorithm......This paper discusses the trade-off between calculations and memory accesses in a 3D graphics tile renderer for visualization of data from medical scanners. The performance requirement of this application is a frame rate of 25 frames per second when rendering 3D models with 2 million triangles, i...... to use a memory access strategy with write-only and read-only phases, and a buffering system, which uses round-robin bank write-access combined with burst read-access....

  16. Distinctive Features Hold a Privileged Status in the Computation of Word Meaning: Implications for Theories of Semantic Memory

    Science.gov (United States)

    Cree, George S.; McNorgan, Chris; McRae, Ken

    2006-01-01

    The authors present data from 2 feature verification experiments designed to determine whether distinctive features have a privileged status in the computation of word meaning. They use an attractor-based connectionist model of semantic memory to derive predictions for the experiments. Contrary to central predictions of the conceptual structure…

  17. The Internet and Computer User Profile: a questionnaire for determining intervention targets in occupational therapy at mental health vocational centers.

    Science.gov (United States)

    Regev, Sivan; Hadas-Lidor, Noami; Rosenberg, Limor

    2016-08-01

    In this study, the assessment tool "Internet and Computer User Profile" questionnaire (ICUP) is presented and validated. It was developed in order to gather information for setting intervention goals to meet current demands. Sixty-eight subjects aged 23-68 participated in the study. The study group (n = 28) was sampled from two vocational centers. The control group consisted of 40 participants from the general population that were sampled by convenience sampling based on the demographics of the study group. Subjects from both groups answered the ICUP questionnaire. Subjects of the study group answered the General Self- Efficacy (GSE) questionnaire and performed the Assessment of Computer Task Performance (ACTP) test in order to examine the convergent validity of the ICUP. Twenty subjects from both groups retook the ICUP questionnaire in order to obtain test-retest results. Differences between groups were tested using multiple analysis of variance (MANOVA) tests. Pearson and Spearman's tests were used for calculating correlations. Cronbach's alpha coefficient and k equivalent were used to assess internal consistency. The results indicate that the questionnaire is valid and reliable. They emphasize that the layout of the ICUP items facilitates in making a comprehensive examination of the client's perception regarding his participation in computer and internet activities. Implications for Rehabiliation The assessment tool "Internet and Computer User Profile" (ICUP) questionnaire is a novel assessment tool that evaluates operative use and individual perception of computer activities. The questionnaire is valid and reliable for use with participants of vocational centers dealing with mental illness. It is essential to facilitate access to computers for people with mental illnesses, seeing that they express similar interest in computers and internet as people from the general population of the same age. Early intervention will be particularly effective for young

  18. Memory and selective attention in multiple sclerosis: cross-sectional computer-based assessment in a large outpatient sample.

    Science.gov (United States)

    Adler, Georg; Lembach, Yvonne

    2015-08-01

    Cognitive impairments may have a severe impact on everyday functioning and quality of life of patients with multiple sclerosis (MS). However, there are some methodological problems in the assessment and only a few studies allow a representative estimate of the prevalence and severity of cognitive impairments in MS patients. We applied a computer-based method, the memory and attention test (MAT), in 531 outpatients with MS, who were assessed at nine neurological practices or specialized outpatient clinics. The findings were compared with those obtained in an age-, sex- and education-matched control group of 84 healthy subjects. Episodic short-term memory was substantially decreased in the MS patients. About 20% of them reached a score of only less than two standard deviations below the mean of the control group. The episodic short-term memory score was negatively correlated with the EDSS score. Minor but also significant impairments in the MS patients were found for verbal short-term memory, episodic working memory and selective attention. The computer-based MAT was found to be useful for a routine assessment of cognition in MS outpatients.

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

    Science.gov (United States)

    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

  20. A single-trace dual-process model of episodic memory: a novel computational account of familiarity and recollection.

    Science.gov (United States)

    Greve, Andrea; Donaldson, David I; van Rossum, Mark C W

    2010-02-01

    Dual-process theories of episodic memory state that retrieval is contingent on two independent processes: familiarity (providing a sense of oldness) and recollection (recovering events and their context). A variety of studies have reported distinct neural signatures for familiarity and recollection, supporting dual-process theory. One outstanding question is whether these signatures reflect the activation of distinct memory traces or the operation of different retrieval mechanisms on a single memory trace. We present a computational model that uses a single neuronal network to store memory traces, but two distinct and independent retrieval processes access the memory. The model is capable of performing familiarity and recollection-based discrimination between old and new patterns, demonstrating that dual-process models need not to rely on multiple independent memory traces, but can use a single trace. Importantly, our putative familiarity and recollection processes exhibit distinct characteristics analogous to those found in empirical data; they diverge in capacity and sensitivity to sparse and correlated patterns, exhibit distinct ROC curves, and account for performance on both item and associative recognition tests. The demonstration that a single-trace, dual-process model can account for a range of empirical findings highlights the importance of distinguishing between neuronal processes and the neuronal representations on which they operate.

  1. Effects of degraded sensory input on memory for speech: behavioral data and a test of biologically constrained computational models.

    Science.gov (United States)

    Piquado, Tepring; Cousins, Katheryn A Q; Wingfield, Arthur; Miller, Paul

    2010-12-13

    Poor hearing acuity reduces memory for spoken words, even when the words are presented with enough clarity for correct recognition. An "effortful hypothesis" suggests that the perceptual effort needed for recognition draws from resources that would otherwise be available for encoding the word in memory. To assess this hypothesis, we conducted a behavioral task requiring immediate free recall of word-lists, some of which contained an acoustically masked word that was just above perceptual threshold. Results show that masking a word reduces the recall of that word and words prior to it, as well as weakening the linking associations between the masked and prior words. In contrast, recall probabilities of words following the masked word are not affected. To account for this effect we conducted computational simulations testing two classes of models: Associative Linking Models and Short-Term Memory Buffer Models. Only a model that integrated both contextual linking and buffer components matched all of the effects of masking observed in our behavioral data. In this Linking-Buffer Model, the masked word disrupts a short-term memory buffer, causing associative links of words in the buffer to be weakened, affecting memory for the masked word and the word prior to it, while allowing links of words following the masked word to be spared. We suggest that these data account for the so-called "effortful hypothesis", where distorted input has a detrimental impact on prior information stored in short-term memory. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. A memory efficient user interface for CLIPS micro-computer applications

    Science.gov (United States)

    Sterle, Mark E.; Mayer, Richard J.; Jordan, Janice A.; Brodale, Howard N.; Lin, Min-Jin

    1990-01-01

    The goal of the Integrated Southern Pine Beetle Expert System (ISPBEX) is to provide expert level knowledge concerning treatment advice that is convenient and easy to use for Forest Service personnel. ISPBEX was developed in CLIPS and delivered on an IBM PC AT class micro-computer, operating with an MS/DOS operating system. This restricted the size of the run time system to 640K. In order to provide a robust expert system, with on-line explanation, help, and alternative actions menus, as well as features that allow the user to back up or execute 'what if' scenarios, a memory efficient menuing system was developed to interface with the CLIPS programs. By robust, we mean an expert system that (1) is user friendly, (2) provides reasonable solutions for a wide variety of domain specific problems, (3) explains why some solutions were suggested but others were not, and (4) provides technical information relating to the problem solution. Several advantages were gained by using this type of user interface (UI). First, by storing the menus on the hard disk (instead of main memory) during program execution, a more robust system could be implemented. Second, since the menus were built rapidly, development time was reduced. Third, the user may try a new scenario by backing up to any of the input screens and revising segments of the original input without having to retype all the information. And fourth, asserting facts from the menus provided for a dynamic and flexible fact base. This UI technology has been applied successfully in expert systems applications in forest management, agriculture, and manufacturing. This paper discusses the architecture of the UI system, human factors considerations, and the menu syntax design.

  3. Serotonergic modulation of spatial working memory: predictions from a computational network model

    Directory of Open Access Journals (Sweden)

    Maria eCano-Colino

    2013-09-01

    Full Text Available Serotonin (5-HT receptors of types 1A and 2A are massively expressed in prefrontal cortex (PFC neurons, an area associated with cognitive function. Hence, 5-HT could be effective in modulating prefrontal-dependent cognitive functions, such as spatial working memory (SWM. However, a direct association between 5-HT and SWM has proved elusive in psycho-pharmacological studies. Recently, a computational network model of the PFC microcircuit was used to explore the relationship between 5‑HT and SWM (Cano-Colino et al. 2013. This study found that both excessive and insufficient 5-HT levels lead to impaired SWM performance in the network, and it concluded that analyzing behavioral responses based on confidence reports could facilitate the experimental identification of SWM behavioral effects of 5‑HT neuromodulation. Such analyses may have confounds based on our limited understanding of metacognitive processes. Here, we extend these results by deriving three additional predictions from the model that do not rely on confidence reports. Firstly, only excessive levels of 5-HT should result in SWM deficits that increase with delay duration. Secondly, excessive 5-HT baseline concentration makes the network vulnerable to distractors at distances that were robust to distraction in control conditions, while the network still ignores distractors efficiently for low 5‑HT levels that impair SWM. Finally, 5-HT modulates neuronal memory fields in neurophysiological experiments: Neurons should be better tuned to the cued stimulus than to the behavioral report for excessive 5-HT levels, while the reverse should happen for low 5-HT concentrations. In all our simulations agonists of 5-HT1A receptors and antagonists of 5-HT2A receptors produced behavioral and physiological effects in line with global 5-HT level increases. Our model makes specific predictions to be tested experimentally and advance our understanding of the neural basis of SWM and its neuromodulation

  4. Conditional bistability, a generic cellular mnemonic mechanism for robust and flexible working memory computations.

    Science.gov (United States)

    Rodriguez, Guillaume; Sarazin, Matthieu; Clemente, Alexandra; Holden, Stephanie; Paz, Jeanne T; Delord, Bruno

    2018-04-30

    Persistent neural activity, the substrate of working memory, is thought to emerge from synaptic reverberation within recurrent networks. However, reverberation models do not robustly explain fundamental dynamics of persistent activity, including high-spiking irregularity, large intertrial variability, and state transitions. While cellular bistability may contribute to persistent activity, its rigidity appears incompatible with persistent activity labile characteristics. Here, we unravel in a cellular model a form of spike-mediated conditional bistability that is robust, generic and provides a rich repertoire of mnemonic computations. Under asynchronous synaptic inputs of the awakened state, conditional bistability generates spiking/bursting episodes, accounting for the irregularity, variability and state transitions characterizing persistent activity. This mechanism has likely been overlooked because of the sub-threshold input it requires and we predict how to assess it experimentally. Our results suggest a reexamination of the role of intrinsic properties in the collective network dynamics responsible for flexible working memory. SIGNIFICANCE STATEMENT This study unravels a novel form of intrinsic neuronal property, i.e. conditional bistability. We show that, thanks of its conditional character, conditional bistability favors the emergence of flexible and robust forms of persistent activity in PFC neural networks, in opposition to previously studied classical forms of absolute bistability. Specifically, we demonstrate for the first time that conditional bistability 1) is a generic biophysical spike-dependent mechanism of layer V pyramidal neurons in the PFC and that 2) it accounts for essential neurodynamical features for the organisation and flexibility of PFC persistent activity (the large irregularity and intertrial variability of the discharge and its organization under discrete stable states), which remain unexplained in a robust fashion by current models

  5. A computational model of fMRI activity in the intraparietal sulcus that supports visual working memory.

    Science.gov (United States)

    Domijan, Dražen

    2011-12-01

    A computational model was developed to explain a pattern of results of fMRI activation in the intraparietal sulcus (IPS) supporting visual working memory for multiobject scenes. The model is based on the hypothesis that dendrites of excitatory neurons are major computational elements in the cortical circuit. Dendrites enable formation of a competitive queue that exhibits a gradient of activity values for nodes encoding different objects, and this pattern is stored in working memory. In the model, brain imaging data are interpreted as a consequence of blood flow arising from dendritic processing. Computer simulations showed that the model successfully simulates data showing the involvement of inferior IPS in object individuation and spatial grouping through representation of objects' locations in space, along with the involvement of superior IPS in object identification through representation of a set of objects' features. The model exhibits a capacity limit due to the limited dynamic range for nodes and the operation of lateral inhibition among them. The capacity limit is fixed in the inferior IPS regardless of the objects' complexity, due to the normalization of lateral inhibition, and variable in the superior IPS, due to the different encoding demands for simple and complex shapes. Systematic variation in the strength of self-excitation enables an understanding of the individual differences in working memory capacity. The model offers several testable predictions regarding the neural basis of visual working memory.

  6. A parallelization study of the general purpose Monte Carlo code MCNP4 on a distributed memory highly parallel computer

    International Nuclear Information System (INIS)

    Yamazaki, Takao; Fujisaki, Masahide; Okuda, Motoi; Takano, Makoto; Masukawa, Fumihiro; Naito, Yoshitaka

    1993-01-01

    The general purpose Monte Carlo code MCNP4 has been implemented on the Fujitsu AP1000 distributed memory highly parallel computer. Parallelization techniques developed and studied are reported. A shielding analysis function of the MCNP4 code is parallelized in this study. A technique to map a history to each processor dynamically and to map control process to a certain processor was applied. The efficiency of parallelized code is up to 80% for a typical practical problem with 512 processors. These results demonstrate the advantages of a highly parallel computer to the conventional computers in the field of shielding analysis by Monte Carlo method. (orig.)

  7. The Effects of Internet Use, Cell Phones and Computer Games on Mental Health of Children and Adolescents

    Directory of Open Access Journals (Sweden)

    Meral Kelleci

    2008-06-01

    Full Text Available The use of digital technology, including computers, cell phones, computer games, and so on, most recently, on-the-go for recreational purposes, has increased among our youth over the past 15 years. Children and adolescent between the ages of 8 to 18 years spend an average of 5-6 hours per day using information and communication technologies. It is a useful progress because of the increase of internet usage which is unlimited, uncontrolled and uninhibited and easiness which arrival all sorts of to informations or persons but this state can cause to some important negative results too. The computer games, the internet explores is gradually estrange from social life the children and adolescent. In this paper, has been mentioned to negative effect of internet usage, computer games on mental health of children and adolescents. [TAF Prev Med Bull 2008; 7(3.000: 253-256

  8. What is the role of spatial processing in the decline of episodic memory in Alzheimer's disease? The "mental frame syncing" hypothesis

    Directory of Open Access Journals (Sweden)

    Silvia eSerino

    2014-03-01

    Full Text Available The current theories on episodic memory suggest a crucial role of spatial processing for an effective retrieval. When prompted by a retrieval cue, the full past scene can be retrieved through the process of pattern completion. Thanks to retrosplenial cortex, this allocentric representation is translated to an egocentric representation in the medial parietal areas via information updating from other cells: place cells inform the viewpoint location, head-direction cells the viewing direction, and grid cells the self-motion signals. Based on several evidence, we argue that a crucial role for an episodic retrieval is played by a "mental frame syncing" between the allocentric view-point dependent representation and the allocentric view-point independent representation. If the mental frame syncing stops, even momentarily, it is difficult to reconstruct a coherent representation for an effective episodic recall. This is what apparently happens in Alzheimer's disease: a break in the mental frame syncing between these two kinds of allocentric representations, underpinned by damage to the hippocampus, may contribute significantly to the early deficit in episodic memory.

  9. Mental rotation impairs attention shifting and short-term memory encoding: neurophysiological evidence against the response-selection bottleneck model of dual-task performance.

    Science.gov (United States)

    Pannebakker, Merel M; Jolicœur, Pierre; van Dam, Wessel O; Band, Guido P H; Ridderinkhof, K Richard; Hommel, Bernhard

    2011-09-01

    Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial attention to a second stimulus (S2). Visual-spatial attention was monitored by using the N2pc component of the ERP. In addition, we examined the sustained posterior contralateral negativity (SPCN) believed to index the retention of information in visual short-term memory. We found modulations of both the N2pc and the SPCN, suggesting that engaging mechanisms of mental rotation impairs the deployment of visual-spatial attention and delays the passage of a representation of S2 into visual short-term memory. Both results suggest interactions between mental rotation and visual-spatial attention in capacity-limited processing mechanisms indicating that response selection is not pivotal in dual-task delays and all three processes are likely to share a common resource like executive control. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Bessel function expansion to reduce the calculation time and memory usage for cylindrical computer-generated holograms.

    Science.gov (United States)

    Sando, Yusuke; Barada, Daisuke; Jackin, Boaz Jessie; Yatagai, Toyohiko

    2017-07-10

    This study proposes a method to reduce the calculation time and memory usage required for calculating cylindrical computer-generated holograms. The wavefront on the cylindrical observation surface is represented as a convolution integral in the 3D Fourier domain. The Fourier transformation of the kernel function involving this convolution integral is analytically performed using a Bessel function expansion. The analytical solution can drastically reduce the calculation time and the memory usage without any cost, compared with the numerical method using fast Fourier transform to Fourier transform the kernel function. In this study, we present the analytical derivation, the efficient calculation of Bessel function series, and a numerical simulation. Furthermore, we demonstrate the effectiveness of the analytical solution through comparisons of calculation time and memory usage.

  11. Determination of strain fields in porous shape memory alloys using micro-computed tomography

    Science.gov (United States)

    Bormann, Therese; Friess, Sebastian; de Wild, Michael; Schumacher, Ralf; Schulz, Georg; Müller, Bert

    2010-09-01

    Shape memory alloys (SMAs) belong to 'intelligent' materials since the metal alloy can change its macroscopic shape as the result of the temperature-induced, reversible martensite-austenite phase transition. SMAs are often applied for medical applications such as stents, hinge-less instruments, artificial muscles, and dental braces. Rapid prototyping techniques, including selective laser melting (SLM), allow fabricating complex porous SMA microstructures. In the present study, the macroscopic shape changes of the SMA test structures fabricated by SLM have been investigated by means of micro computed tomography (μCT). For this purpose, the SMA structures are placed into the heating stage of the μCT system SkyScan 1172™ (SkyScan, Kontich, Belgium) to acquire three-dimensional datasets above and below the transition temperature, i.e. at room temperature and at about 80°C, respectively. The two datasets were registered on the basis of an affine registration algorithm with nine independent parameters - three for the translation, three for the rotation and three for the scaling in orthogonal directions. Essentially, the scaling parameters characterize the macroscopic deformation of the SMA structure of interest. Furthermore, applying the non-rigid registration algorithm, the three-dimensional strain field of the SMA structure on the micrometer scale comes to light. The strain fields obtained will serve for the optimization of the SLM-process and, more important, of the design of the complex shaped SMA structures for tissue engineering and medical implants.

  12. Procedural Memory: Computer Learning in Control Subjects and in Parkinson’s Disease Patients

    Directory of Open Access Journals (Sweden)

    C. Thomas-Antérion

    1996-01-01

    Full Text Available We used perceptual motor tasks involving the learning of mouse control by looking at a Macintosh computer screen. We studied 90 control subjects aged between sixteen and seventy-five years. There was a significant time difference between the scales of age but improvement was the same for all subjects. We also studied 24 patients with Parkinson's disease (PD. We observed an influence of age and also of educational levels. The PD patients had difficulties of learning in all tests but they did not show differences in time when compared to the control group in the first learning session (Student's t-test. They learned two or four and a half times less well than the control group. In the first test, they had some difficulty in initiating the procedure and learned eight times less well than the control group. Performances seemed to be heterogeneous: patients with only tremor (seven and patients without treatment (five performed better than others but learned less. Success in procedural tasks for the PD group seemed to depend on the capacity to initiate the response and not on the development of an accurate strategy. Many questions still remain unanswered, and we have to study different kinds of implicit memory tasks to differentiate performance in control and basal ganglia groups.

  13. Context-dependent memory decay is evidence of effort minimization in motor learning: a computational study

    OpenAIRE

    Takiyama, Ken

    2015-01-01

    Recent theoretical models suggest that motor learning includes at least two processes: error minimization and memory decay. While learning a novel movement, a motor memory of the movement is gradually formed to minimize the movement error between the desired and actual movements in each training trial, but the memory is slightly forgotten in each trial. The learning effects of error minimization trained with a certain movement are partially available in other non-trained movements, and this t...

  14. The Role of Context-Related Parameters in Adults’ Mental Computational Acts (El papel de los parámetros relacionados con el contexto en actos de cálculo mental en adultos

    Directory of Open Access Journals (Sweden)

    Nirmala Naresh

    2012-01-01

    Full Text Available Researchers who have carried out studies pertaining to mental computation and everyday mathematics point out that adults and children reason intuitively based upon experiences within specific contexts; they use invented strategies of their own to solve real-life problems. We draw upon research areas of mental computation and everyday mathematics to report on a study that investigated adults’ use of mental mathematics in everyday settings. In this paper, we report on one adult’s use of mental computation at work and highlight the role of context and context related parameters in his mental mathematical activities.Los investigadores que han realizado estudios relacionados con el cálculo mental y las matemáticas cotidianas señalan que los adultos y los niños razonan intuitivamente basándose en las experiencias de contextos específicos; usan estrategias inventadas por sí mismos para resolver problemas de la vida real. Nos basamos en las áreas de investigación del cálculo mental y las matemáticas cotidianas para informar sobre un estudio que investigó el uso que hacen los adultos de la matemática mental en el entorno cotidiano. En este artículo, informamos sobre el uso que hace un adulto del cálculo mental en su trabajo y destacamos el papel del contexto y de los parámetros relacionados con el contexto en sus actividades matemáticas mentales.

  15. Computational analysis of TRAPPC9: candidate gene for autosomal recessive non-syndromic mental retardation.

    Science.gov (United States)

    Khattak, Naureen Aslam; Mir, Asif

    2014-01-01

    Mental retardation (MR)/ intellectual disability (ID) is a neuro-developmental disorder characterized by a low intellectual quotient (IQ) and deficits in adaptive behavior related to everyday life tasks such as delayed language acquisition, social skills or self-help skills with onset before age 18. To date, a few genes (PRSS12, CRBN, CC2D1A, GRIK2, TUSC3, TRAPPC9, TECR, ST3GAL3, MED23, MAN1B1, NSUN1) for autosomal-recessive forms of non syndromic MR (NS-ARMR) have been identified and established in various families with ID. The recently reported candidate gene TRAPPC9 was selected for computational analysis to explore its potentially important role in pathology as it is the only gene for ID reported in more than five different familial cases worldwide. YASARA (12.4.1) was utilized to generate three dimensional structures of the candidate gene TRAPPC9. Hybrid structure prediction was employed. Crystal Structure of a Conserved Metalloprotein From Bacillus Cereus (3D19-C) was selected as best suitable template using position-specific iteration-BLAST. Template (3D19-C) parameters were based on E-value, Z-score and resolution and quality score of 0.32, -1.152, 2.30°A and 0.684 respectively. Model reliability showed 93.1% residues placed in the most favored region with 96.684 quality factor, and overall 0.20 G-factor (dihedrals 0.06 and covalent 0.39 respectively). Protein-Protein docking analysis demonstrated that TRAPPC9 showed strong interactions of the amino acid residues S(253), S(251), Y(256), G(243), D(131) with R(105), Q(425), W(226), N(255), S(233), its functional partner 1KBKB. Protein-protein interacting residues could facilitate the exploration of structural and functional outcomes of wild type and mutated TRAPCC9 protein. Actively involved residues can be used to elucidate the binding properties of the protein, and to develop drug therapy for NS-ARMR patients.

  16. Computational Modeling of Shape Memory Polymer Origami that Responds to Light

    Science.gov (United States)

    Mailen, Russell William

    Shape memory polymers (SMPs) transform in response to external stimuli, such as infrared (IR) light. Although SMPs have many applications, this investigation focuses on their use as actuators in self-folding origami structures. Ink patterned on the surface of the SMP sheet absorbs thermal energy from the IR light, which produces localized heating. The material shrinks wherever the activation temperature is exceeded and can produce out-of-plane deformation. The time and temperature dependent response of these SMPs provides unique opportunities for developing complex three-dimensional (3D) structures from initially flat sheets through self-folding origami, but the application of this technique requires predicting accurately the final folded or deformed shape. Furthermore, current computational approaches for SMPs do not fully couple the thermo-mechanical response of the material. Hence, a proposed nonlinear, 3D, thermo-viscoelastic finite element framework was formulated to predict deformed shapes for different self-folding systems and compared to experimental results for self-folding origami structures. A detailed understanding of the shape memory response and the effect of controllable design parameters, such as the ink pattern, pre-strain conditions, and applied thermal and mechanical fields, allows for a predictive understanding and design of functional, 3D structures. The proposed modeling framework was used to obtain a fundamental understanding of the thermo-mechanical behavior of SMPs and the impact of the material behavior on hinged self-folding. These predictions indicated how the thermal and mechanical conditions during pre-strain significantly affect the shrinking and folding response of the SMP. Additionally, the externally applied thermal loads significantly influenced the folding rate and maximum bending angle. The computational framework was also adapted to understand the effects of fully coupling the thermal and mechanical response of the material

  17. Static Computer Memory Integrity Testing (SCMIT): An experiment flown on STS-40 as part of GAS payload G-616

    Science.gov (United States)

    Hancock, Thomas

    1993-01-01

    This experiment investigated the integrity of static computer memory (floppy disk media) when exposed to the environment of low earth orbit. The experiment attempted to record soft-event upsets (bit-flips) in static computer memory. Typical conditions that exist in low earth orbit that may cause soft-event upsets include: cosmic rays, low level background radiation, charged fields, static charges, and the earth's magnetic field. Over the years several spacecraft have been affected by soft-event upsets (bit-flips), and these events have caused a loss of data or affected spacecraft guidance and control. This paper describes a commercial spin-off that is being developed from the experiment.

  18. Elucidation and Optimization of Resistive Random Access Memory Switching Behavior for Advanced Computing Applications

    Science.gov (United States)

    Alamgir, Zahiruddin

    RRAM has recently emerged as a strong candidate for non-volatile memory (NVM). Beyond memory applications, RRAM holds promise for use in performing logic functions, mimicking neuromorphic activities, enabling multi-level switching, and as one of the key elements of hardware based encryption or signal processing systems. It has been shown previously that RRAM resistance levels can be changed by adjusting compliance current or voltage level. This characteristic makes RRAM suitable for use in setting the synaptic weight in neuromorphic computing circuits. RRAM is also considered as a key element in hardware encryption systems, to produce unique and reproducible signals. However, a key challenge to implement RRAM in these applications is significant cycle to cycle performance variability. We sought to develop RRAM that can be tuned to different resistance levels gradually, with high reliability, and low variability. To achieve this goal, we focused on elucidating the conduction mechanisms underlying the resistive switching behavior for these devices. Electrical conduction mechanisms were determined by curve fitting I-V data using different current conduction equations. Temperature studies were also performed to corroborate these data. It was found that Schottky barrier height and width modulation was one of the key parameters that could be tuned to achieve different resistance levels, and for switching resistance states, primarily via oxygen vacancy movement. Oxygen exchange layers with different electronegativity were placed between top electrode and the oxide layer of TaOx devices to determine the effect of oxygen vacancy concentrations and gradients in these devices. It was found that devices with OELs with lower electronegativity tend to yield greater separation in the OFF vs. ON state resistance levels. As an extension of this work, TaOx based RRAM with Hf as the OEL was fabricated and could be tuned to different resistance level using pulse width and height

  19. Computational complexity and memory usage for multi-frontal direct solvers used in p finite element analysis

    KAUST Repository

    Calo, Victor M.; Collier, Nathan; Pardo, David; Paszyński, Maciej R.

    2011-01-01

    The multi-frontal direct solver is the state of the art for the direct solution of linear systems. This paper provides computational complexity and memory usage estimates for the application of the multi-frontal direct solver algorithm on linear systems resulting from p finite elements. Specifically we provide the estimates for systems resulting from C0 polynomial spaces spanned by B-splines. The structured grid and uniform polynomial order used in isogeometric meshes simplifies the analysis.

  20. Computational complexity and memory usage for multi-frontal direct solvers used in p finite element analysis

    KAUST Repository

    Calo, Victor M.

    2011-05-14

    The multi-frontal direct solver is the state of the art for the direct solution of linear systems. This paper provides computational complexity and memory usage estimates for the application of the multi-frontal direct solver algorithm on linear systems resulting from p finite elements. Specifically we provide the estimates for systems resulting from C0 polynomial spaces spanned by B-splines. The structured grid and uniform polynomial order used in isogeometric meshes simplifies the analysis.

  1. Information processing in bacteria: memory, computation, and statistical physics: a key issues review

    International Nuclear Information System (INIS)

    Lan, Ganhui; Tu, Yuhai

    2016-01-01

    preserving information, it does not reveal the underlying mechanism that leads to the observed input-output relationship, nor does it tell us much about which information is important for the organism and how biological systems use information to carry out specific functions. To do that, we need to develop models of the biological machineries, e.g. biochemical networks and neural networks, to understand the dynamics of biological information processes. This is a much more difficult task. It requires deep knowledge of the underlying biological network—the main players (nodes) and their interactions (links)—in sufficient detail to build a model with predictive power, as well as quantitative input-output measurements of the system under different perturbations (both genetic variations and different external conditions) to test the model predictions to guide further development of the model. Due to the recent growth of biological knowledge thanks in part to high throughput methods (sequencing, gene expression microarray, etc) and development of quantitative in vivo techniques such as various florescence technology, these requirements are starting to be realized in different biological systems. The possible close interaction between quantitative experimentation and theoretical modeling has made systems biology an attractive field for physicists interested in quantitative biology. In this review, we describe some of the recent work in developing a quantitative predictive model of bacterial chemotaxis, which can be considered as the hydrogen atom of systems biology. Using statistical physics approaches, such as the Ising model and Langevin equation, we study how bacteria, such as E. coli, sense and amplify external signals, how they keep a working memory of the stimuli, and how they use these data to compute the chemical gradient. In particular, we will describe how E. coli cells avoid cross-talk in a heterogeneous receptor cluster to keep a ligand-specific memory. We will also

  2. Information processing in bacteria: memory, computation, and statistical physics: a key issues review

    Science.gov (United States)

    Lan, Ganhui; Tu, Yuhai

    2016-05-01

    preserving information, it does not reveal the underlying mechanism that leads to the observed input-output relationship, nor does it tell us much about which information is important for the organism and how biological systems use information to carry out specific functions. To do that, we need to develop models of the biological machineries, e.g. biochemical networks and neural networks, to understand the dynamics of biological information processes. This is a much more difficult task. It requires deep knowledge of the underlying biological network—the main players (nodes) and their interactions (links)—in sufficient detail to build a model with predictive power, as well as quantitative input-output measurements of the system under different perturbations (both genetic variations and different external conditions) to test the model predictions to guide further development of the model. Due to the recent growth of biological knowledge thanks in part to high throughput methods (sequencing, gene expression microarray, etc) and development of quantitative in vivo techniques such as various florescence technology, these requirements are starting to be realized in different biological systems. The possible close interaction between quantitative experimentation and theoretical modeling has made systems biology an attractive field for physicists interested in quantitative biology. In this review, we describe some of the recent work in developing a quantitative predictive model of bacterial chemotaxis, which can be considered as the hydrogen atom of systems biology. Using statistical physics approaches, such as the Ising model and Langevin equation, we study how bacteria, such as E. coli, sense and amplify external signals, how they keep a working memory of the stimuli, and how they use these data to compute the chemical gradient. In particular, we will describe how E. coli cells avoid cross-talk in a heterogeneous receptor cluster to keep a ligand-specific memory. We will also

  3. Information processing in bacteria: memory, computation, and statistical physics: a key issues review.

    Science.gov (United States)

    Lan, Ganhui; Tu, Yuhai

    2016-05-01

    preserving information, it does not reveal the underlying mechanism that leads to the observed input-output relationship, nor does it tell us much about which information is important for the organism and how biological systems use information to carry out specific functions. To do that, we need to develop models of the biological machineries, e.g. biochemical networks and neural networks, to understand the dynamics of biological information processes. This is a much more difficult task. It requires deep knowledge of the underlying biological network-the main players (nodes) and their interactions (links)-in sufficient detail to build a model with predictive power, as well as quantitative input-output measurements of the system under different perturbations (both genetic variations and different external conditions) to test the model predictions to guide further development of the model. Due to the recent growth of biological knowledge thanks in part to high throughput methods (sequencing, gene expression microarray, etc) and development of quantitative in vivo techniques such as various florescence technology, these requirements are starting to be realized in different biological systems. The possible close interaction between quantitative experimentation and theoretical modeling has made systems biology an attractive field for physicists interested in quantitative biology. In this review, we describe some of the recent work in developing a quantitative predictive model of bacterial chemotaxis, which can be considered as the hydrogen atom of systems biology. Using statistical physics approaches, such as the Ising model and Langevin equation, we study how bacteria, such as E. coli, sense and amplify external signals, how they keep a working memory of the stimuli, and how they use these data to compute the chemical gradient. In particular, we will describe how E. coli cells avoid cross-talk in a heterogeneous receptor cluster to keep a ligand-specific memory. We will also

  4. Episodic grammar: a computational model of the interaction between episodic and semantic memory in language processing

    NARCIS (Netherlands)

    Borensztajn, G.; Zuidema, W.; Carlson, L.; Hoelscher, C.; Shipley, T.F.

    2011-01-01

    We present a model of the interaction of semantic and episodic memory in language processing. Our work shows how language processing can be understood in terms of memory retrieval. We point out that the perceived dichotomy between rule-based versus exemplar-based language modelling can be

  5. Optical interconnection network for parallel access to multi-rank memory in future computing systems.

    Science.gov (United States)

    Wang, Kang; Gu, Huaxi; Yang, Yintang; Wang, Kun

    2015-08-10

    With the number of cores increasing, there is an emerging need for a high-bandwidth low-latency interconnection network, serving core-to-memory communication. In this paper, aiming at the goal of simultaneous access to multi-rank memory, we propose an optical interconnection network for core-to-memory communication. In the proposed network, the wavelength usage is delicately arranged so that cores can communicate with different ranks at the same time and broadcast for flow control can be achieved. A distributed memory controller architecture that works in a pipeline mode is also designed for efficient optical communication and transaction address processes. The scaling method and wavelength assignment for the proposed network are investigated. Compared with traditional electronic bus-based core-to-memory communication, the simulation results based on the PARSEC benchmark show that the bandwidth enhancement and latency reduction are apparent.

  6. Context-dependent memory decay is evidence of effort minimization in motor learning: a computational study.

    Science.gov (United States)

    Takiyama, Ken

    2015-01-01

    Recent theoretical models suggest that motor learning includes at least two processes: error minimization and memory decay. While learning a novel movement, a motor memory of the movement is gradually formed to minimize the movement error between the desired and actual movements in each training trial, but the memory is slightly forgotten in each trial. The learning effects of error minimization trained with a certain movement are partially available in other non-trained movements, and this transfer of the learning effect can be reproduced by certain theoretical frameworks. Although most theoretical frameworks have assumed that a motor memory trained with a certain movement decays at the same speed during performing the trained movement as non-trained movements, a recent study reported that the motor memory decays faster during performing the trained movement than non-trained movements, i.e., the decay rate of motor memory is movement or context dependent. Although motor learning has been successfully modeled based on an optimization framework, e.g., movement error minimization, the type of optimization that can lead to context-dependent memory decay is unclear. Thus, context-dependent memory decay raises the question of what is optimized in motor learning. To reproduce context-dependent memory decay, I extend a motor primitive framework. Specifically, I introduce motor effort optimization into the framework because some previous studies have reported the existence of effort optimization in motor learning processes and no conventional motor primitive model has yet considered the optimization. Here, I analytically and numerically revealed that context-dependent decay is a result of motor effort optimization. My analyses suggest that context-dependent decay is not merely memory decay but is evidence of motor effort optimization in motor learning.

  7. Context-dependent memory decay is evidence of effort minimization in motor learning: A computational study

    Directory of Open Access Journals (Sweden)

    Ken eTakiyama

    2015-02-01

    Full Text Available Recent theoretical models suggest that motor learning includes at least two processes: error minimization and memory decay. While learning a novel movement, a motor memory of the movement is gradually formed to minimize the movement error between the desired and actual movements in each training trial, but the memory is slightly forgotten in each trial. The learning effects of error minimization trained with a certain movement are partially available in other non-trained movements, and this transfer of the learning effect can be reproduced by certain theoretical frameworks. Although most theoretical frameworks have assumed that a motor memory trained with a certain movement decays at the same speed during performing the trained movement as non-trained movements, a recent study reported that the motor memory decays faster during performing the trained movement than non-trained movements, i.e., the decay rate of motor memory is movement or context dependent. Although motor learning has been successfully modeled based on an optimization framework, e.g., movement error minimization, the type of optimization that can lead to context-dependent memory decay is unclear. Thus, context-dependent memory decay raises the question of what is optimized in motor learning. To reproduce context-dependent memory decay, I extend a motor primitive framework. Specifically, I introduce motor effort optimization into the framework because some previous studies have reported the existence of effort optimization in motor learning processes and no conventional motor primitive model has yet considered the optimization. Here, I analytically and numerically revealed that context-dependent decay is a result of motor effort optimization. My analyses suggest that context-dependent decay is not merely memory decay but is evidence of motor effort optimization in motor learning.

  8. Individual Differences in Strategy Use on Division Problems: Mental versus Written Computation

    Science.gov (United States)

    Hickendorff, Marian; van Putten, Cornelis M.; Verhelst, Norman D.; Heiser, Willem J.

    2010-01-01

    Individual differences in strategy use (choice and accuracy) were analyzed. A sample of 362 Grade 6 students solved complex division problems under 2 different conditions. In the choice condition students were allowed to use either a mental or a written strategy. In the subsequent no-choice condition, they were required to use a written strategy.…

  9. Excessive computer game playing among Norwegian adults: self-reported consequences of playing and association with mental health problems.

    Science.gov (United States)

    Wenzel, H G; Bakken, I J; Johansson, A; Götestam, K G; Øren, Anita

    2009-12-01

    Computer games are the most advanced form of gaming. For most people, the playing is an uncomplicated leisure activity; however, for a minority the gaming becomes excessive and is associated with negative consequences. The aim of the present study was to investigate computer game-playing behaviour in the general adult Norwegian population, and to explore mental health problems and self-reported consequences of playing. The survey includes 3,405 adults 16 to 74 years old (Norway 2007, response rate 35.3%). Overall, 65.5% of the respondents reported having ever played computer games (16-29 years, 93.9%; 30-39 years, 85.0%; 40-59 years, 56.2%; 60-74 years, 25.7%). Among 2,170 players, 89.8% reported playing less than 1 hr. as a daily average over the last month, 5.0% played 1-2 hr. daily, 3.1% played 2-4 hr. daily, and 2.2% reported playing > 4 hr. daily. The strongest risk factor for playing > 4 hr. daily was being an online player, followed by male gender, and single marital status. Reported negative consequences of computer game playing increased strongly with average daily playing time. Furthermore, prevalence of self-reported sleeping problems, depression, suicide ideations, anxiety, obsessions/ compulsions, and alcohol/substance abuse increased with increasing playing time. This study showed that adult populations should also be included in research on computer game-playing behaviour and its consequences.

  10. Coupling Computer Codes for The Analysis of Severe Accident Using A Pseudo Shared Memory Based on MPI

    International Nuclear Information System (INIS)

    Cho, Young Chul; Park, Chang-Hwan; Kim, Dong-Min

    2016-01-01

    As there are four codes in-vessel analysis code (CSPACE), ex-vessel analysis code (SACAP), corium behavior analysis code (COMPASS), and fission product behavior analysis code, for the analysis of severe accident, it is complex to implement the coupling of codes with the similar methodologies for RELAP and CONTEMPT or SPACE and CAP. Because of that, an efficient coupling so called Pseudo shared memory architecture was introduced. In this paper, coupling methodologies will be compared and the methodology used for the analysis of severe accident will be discussed in detail. The barrier between in-vessel and ex-vessel has been removed for the analysis of severe accidents with the implementation of coupling computer codes with pseudo shared memory architecture based on MPI. The remaining are proper choice and checking of variables and values for the selected severe accident scenarios, e.g., TMI accident. Even though it is possible to couple more than two computer codes with pseudo shared memory architecture, the methodology should be revised to couple parallel codes especially when they are programmed using MPI

  11. The MUSOS (MUsic SOftware System) Toolkit: A computer-based, open source application for testing memory for melodies.

    Science.gov (United States)

    Rainsford, M; Palmer, M A; Paine, G

    2018-04-01

    Despite numerous innovative studies, rates of replication in the field of music psychology are extremely low (Frieler et al., 2013). Two key methodological challenges affecting researchers wishing to administer and reproduce studies in music cognition are the difficulty of measuring musical responses, particularly when conducting free-recall studies, and access to a reliable set of novel stimuli unrestricted by copyright or licensing issues. In this article, we propose a solution for these challenges in computer-based administration. We present a computer-based application for testing memory for melodies. Created using the software Max/MSP (Cycling '74, 2014a), the MUSOS (Music Software System) Toolkit uses a simple modular framework configurable for testing common paradigms such as recall, old-new recognition, and stem completion. The program is accompanied by a stimulus set of 156 novel, copyright-free melodies, in audio and Max/MSP file formats. Two pilot tests were conducted to establish the properties of the accompanying stimulus set that are relevant to music cognition and general memory research. By using this software, a researcher without specialist musical training may administer and accurately measure responses from common paradigms used in the study of memory for music.

  12. Coupling Computer Codes for The Analysis of Severe Accident Using A Pseudo Shared Memory Based on MPI

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Chul; Park, Chang-Hwan; Kim, Dong-Min [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    As there are four codes in-vessel analysis code (CSPACE), ex-vessel analysis code (SACAP), corium behavior analysis code (COMPASS), and fission product behavior analysis code, for the analysis of severe accident, it is complex to implement the coupling of codes with the similar methodologies for RELAP and CONTEMPT or SPACE and CAP. Because of that, an efficient coupling so called Pseudo shared memory architecture was introduced. In this paper, coupling methodologies will be compared and the methodology used for the analysis of severe accident will be discussed in detail. The barrier between in-vessel and ex-vessel has been removed for the analysis of severe accidents with the implementation of coupling computer codes with pseudo shared memory architecture based on MPI. The remaining are proper choice and checking of variables and values for the selected severe accident scenarios, e.g., TMI accident. Even though it is possible to couple more than two computer codes with pseudo shared memory architecture, the methodology should be revised to couple parallel codes especially when they are programmed using MPI.

  13. Fostering multidisciplinary learning through computer-supported collaboration script: The role of a transactive memory script

    NARCIS (Netherlands)

    Noroozi, O.; Weinberger, A.; Biemans, H.J.A.; Teasley, S.D.; Mulder, M.

    2012-01-01

    For solving many of today's complex problems, professionals need to collaborate in multidisciplinary teams. Facilitation of knowledge awareness and coordination among group members, that is through a Transactive Memory System (TMS), is vital in multidisciplinary collaborative settings. Online

  14. Construction and Application of an AMR Algorithm for Distributed Memory Computers

    OpenAIRE

    Deiterding, Ralf

    2003-01-01

    While the parallelization of blockstructured adaptive mesh refinement techniques is relatively straight-forward on shared memory architectures, appropriate distribution strategies for the emerging generation of distributed memory machines are a topic of on-going research. In this paper, a locality-preserving domain decomposition is proposed that partitions the entire AMR hierarchy from the base level on. It is shown that the approach reduces the communication costs and simplifies the im...

  15. The effects of working memory on brain-computer interface performance.

    Science.gov (United States)

    Sprague, Samantha A; McBee, Matthew T; Sellers, Eric W

    2016-02-01

    The purpose of the present study is to evaluate the relationship between working memory and BCI performance. Participants took part in two separate sessions. The first session consisted of three computerized tasks. The List Sorting Working Memory Task was used to measure working memory, the Picture Vocabulary Test was used to measure general intelligence, and the Dimensional Change Card Sort Test was used to measure executive function, specifically cognitive flexibility. The second session consisted of a P300-based BCI copy-spelling task. The results indicate that both working memory and general intelligence are significant predictors of BCI performance. This suggests that working memory training could be used to improve performance on a BCI task. Working memory training may help to reduce a portion of the individual differences that exist in BCI performance allowing for a wider range of users to successfully operate the BCI system as well as increase the BCI performance of current users. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  16. Time complexity analysis for distributed memory computers: implementation of parallel conjugate gradient method

    NARCIS (Netherlands)

    Hoekstra, A.G.; Sloot, P.M.A.; Haan, M.J.; Hertzberger, L.O.; van Leeuwen, J.

    1991-01-01

    New developments in Computer Science, both hardware and software, offer researchers, such as physicists, unprecedented possibilities to solve their computational intensive problems.However, full exploitation of e.g. new massively parallel computers, parallel languages or runtime environments

  17. A highly efficient parallel algorithm for solving the neutron diffusion nodal equations on shared-memory computers

    International Nuclear Information System (INIS)

    Azmy, Y.Y.; Kirk, B.L.

    1990-01-01

    Modern parallel computer architectures offer an enormous potential for reducing CPU and wall-clock execution times of large-scale computations commonly performed in various applications in science and engineering. Recently, several authors have reported their efforts in developing and implementing parallel algorithms for solving the neutron diffusion equation on a variety of shared- and distributed-memory parallel computers. Testing of these algorithms for a variety of two- and three-dimensional meshes showed significant speedup of the computation. Even for very large problems (i.e., three-dimensional fine meshes) executed concurrently on a few nodes in serial (nonvector) mode, however, the measured computational efficiency is very low (40 to 86%). In this paper, the authors present a highly efficient (∼85 to 99.9%) algorithm for solving the two-dimensional nodal diffusion equations on the Sequent Balance 8000 parallel computer. Also presented is a model for the performance, represented by the efficiency, as a function of problem size and the number of participating processors. The model is validated through several tests and then extrapolated to larger problems and more processors to predict the performance of the algorithm in more computationally demanding situations

  18. Perspectives on Games, Computers, and Mental Health: Questions about Paradoxes, Evidences, and Challenges

    OpenAIRE

    Desseilles, Martin

    2016-01-01

    In the field of mental health, games and computerized games present questions about paradoxes, evidences, and challenges. This perspective article offers perspectives and personal opinion about these questions, evidences, and challenges with an objective of presenting several ideas and issues in this rapidly developing field. First, games raise some questions in the sense of the paradox between a game and an issue, as well as the paradox of using an amusing game to treat a serious pathology. ...

  19. Trial-by-Trial Modulation of Associative Memory Formation by Reward Prediction Error and Reward Anticipation as Revealed by a Biologically Plausible Computational Model.

    Science.gov (United States)

    Aberg, Kristoffer C; Müller, Julia; Schwartz, Sophie

    2017-01-01

    Anticipation and delivery of rewards improves memory formation, but little effort has been made to disentangle their respective contributions to memory enhancement. Moreover, it has been suggested that the effects of reward on memory are mediated by dopaminergic influences on hippocampal plasticity. Yet, evidence linking memory improvements to actual reward computations reflected in the activity of the dopaminergic system, i.e., prediction errors and expected values, is scarce and inconclusive. For example, different previous studies reported that the magnitude of prediction errors during a reinforcement learning task was a positive, negative, or non-significant predictor of successfully encoding simultaneously presented images. Individual sensitivities to reward and punishment have been found to influence the activation of the dopaminergic reward system and could therefore help explain these seemingly discrepant results. Here, we used a novel associative memory task combined with computational modeling and showed independent effects of reward-delivery and reward-anticipation on memory. Strikingly, the computational approach revealed positive influences from both reward delivery, as mediated by prediction error magnitude, and reward anticipation, as mediated by magnitude of expected value, even in the absence of behavioral effects when analyzed using standard methods, i.e., by collapsing memory performance across trials within conditions. We additionally measured trait estimates of reward and punishment sensitivity and found that individuals with increased reward (vs. punishment) sensitivity had better memory for associations encoded during positive (vs. negative) prediction errors when tested after 20 min, but a negative trend when tested after 24 h. In conclusion, modeling trial-by-trial fluctuations in the magnitude of reward, as we did here for prediction errors and expected value computations, provides a comprehensive and biologically plausible description of

  20. Local annealing of shape memory alloys using laser scanning and computer vision

    Science.gov (United States)

    Hafez, Moustapha; Bellouard, Yves; Sidler, Thomas C.; Clavel, Reymond; Salathe, Rene-Paul

    2000-11-01

    A complete set-up for local annealing of Shape Memory Alloys (SMA) is proposed. Such alloys, when plastically deformed at a given low temperature, have the ability to recover a previously memorized shape simply by heating up to a higher temperature. They find more and more applications in the fields of robotics and micro engineering. There is a tremendous advantage in using local annealing because this process can produce monolithic parts, which have different mechanical behavior at different location of the same body. Using this approach, it is possible to integrate all the functionality of a device within one piece of material. The set-up is based on a 2W-laser diode emitting at 805nm and a scanner head. The laser beam is coupled into an optical fiber of 60(mu) in diameter. The fiber output is focused on the SMA work-piece using a relay lens system with a 1:1 magnification, resulting in a spot diameter of 60(mu) . An imaging system is used to control the position of the laser spot on the sample. In order to displace the spot on the surface a tip/tilt laser scanner is used. The scanner is positioned in a pre-objective configuration and allows a scan field size of more than 10 x 10 mm2. A graphical user interface of the scan field allows the user to quickly set up marks and alter their placement and power density. This is achieved by computer controlling X and Y positions of the scanner as well as the laser diode power. A SMA micro-gripper with a surface area less than 1 mm2 and an opening of the jaws of 200(mu) has been realized using this set-up. It is electrically actuated and a controlled force of 16mN can be applied to hold and release small objects such as graded index micro-lenses at a cycle time of typically 1s.

  1. Detecting number processing and mental calculation in patients with disorders of consciousness using a hybrid brain-computer interface system.

    Science.gov (United States)

    Li, Yuanqing; Pan, Jiahui; He, Yanbin; Wang, Fei; Laureys, Steven; Xie, Qiuyou; Yu, Ronghao

    2015-12-15

    For patients with disorders of consciousness such as coma, a vegetative state or a minimally conscious state, one challenge is to detect and assess the residual cognitive functions in their brains. Number processing and mental calculation are important brain functions but are difficult to detect in patients with disorders of consciousness using motor response-based clinical assessment scales such as the Coma Recovery Scale-Revised due to the patients' motor impairments and inability to provide sufficient motor responses for number- and calculation-based communication. In this study, we presented a hybrid brain-computer interface that combines P300 and steady state visual evoked potentials to detect number processing and mental calculation in Han Chinese patients with disorders of consciousness. Eleven patients with disorders of consciousness who were in a vegetative state (n = 6) or in a minimally conscious state (n = 3) or who emerged from a minimally conscious state (n = 2) participated in the brain-computer interface-based experiment. During the experiment, the patients with disorders of consciousness were instructed to perform three tasks, i.e., number recognition, number comparison, and mental calculation, including addition and subtraction. In each experimental trial, an arithmetic problem was first presented. Next, two number buttons, only one of which was the correct answer to the problem, flickered at different frequencies to evoke steady state visual evoked potentials, while the frames of the two buttons flashed in a random order to evoke P300 potentials. The patients needed to focus on the target number button (the correct answer). Finally, the brain-computer interface system detected P300 and steady state visual evoked potentials to determine the button to which the patients attended, further presenting the results as feedback. Two of the six patients who were in a vegetative state, one of the three patients who were in a minimally conscious state, and

  2. In-Depth Analysis of Computer Memory Acquisition Software for Forensic Purposes.

    Science.gov (United States)

    McDown, Robert J; Varol, Cihan; Carvajal, Leonardo; Chen, Lei

    2016-01-01

    The comparison studies on random access memory (RAM) acquisition tools are either limited in metrics or the selected tools were designed to be executed in older operating systems. Therefore, this study evaluates widely used seven shareware or freeware/open source RAM acquisition forensic tools that are compatible to work with the latest 64-bit Windows operating systems. These tools' user interface capabilities, platform limitations, reporting capabilities, total execution time, shared and proprietary DLLs, modified registry keys, and invoked files during processing were compared. We observed that Windows Memory Reader and Belkasoft's Live Ram Capturer leaves the least fingerprints in memory when loaded. On the other hand, ProDiscover and FTK Imager perform poor in memory usage, processing time, DLL usage, and not-wanted artifacts introduced to the system. While Belkasoft's Live Ram Capturer is the fastest to obtain an image of the memory, Pro Discover takes the longest time to do the same job. © 2015 American Academy of Forensic Sciences.

  3. USE OF VIDEOGAMES AND COMPUTER GAMES: INFLUENCES ON ATTENTION, MEMORY, ACADEMIC ACHIEVEMENT AND PROBLEMS BEHAVIOR

    Directory of Open Access Journals (Sweden)

    Harold Germán Rodríguez Celis

    2011-12-01

    Full Text Available This study was designed to identify the relationship between video and computergames use on attention, memory, academic performance and problemsbehavior in school children in Bogotá. Memory and attention were assessedusing a set of different scales of ENI Battery (Matute, Rosselli, Ardila, & Ostrosky-Solís, 2007. For Academic performance, school newsletters were used.Behavioral problems were assessed through the CBCL / 6 -18 questionnaire(Child Behavior Checklist of (Achenbach & Edelbrock, 1983. 123 children and99 parents were enrolled in 2 factorial design experimental studies. The resultsdid not support the hypothesis of a significant change in memory tests, orintra-subject selective visual and hearing attention. However, these variablesshowed significant differences among children exposed to habitual videogamesconsumption. No differences were found between the level of regular videogames consumption in school children and academic performance variables orbehavioral problems.

  4. A Compute Capable SSD Architecture for Next-Generation Non-volatile Memories

    Energy Technology Data Exchange (ETDEWEB)

    De, Arup [Univ. of California, San Diego, CA (United States)

    2014-01-01

    Existing storage technologies (e.g., disks and ash) are failing to cope with the processor and main memory speed and are limiting the overall perfor- mance of many large scale I/O or data-intensive applications. Emerging fast byte-addressable non-volatile memory (NVM) technologies, such as phase-change memory (PCM), spin-transfer torque memory (STTM) and memristor are very promising and are approaching DRAM-like performance with lower power con- sumption and higher density as process technology scales. These new memories are narrowing down the performance gap between the storage and the main mem- ory and are putting forward challenging problems on existing SSD architecture, I/O interface (e.g, SATA, PCIe) and software. This dissertation addresses those challenges and presents a novel SSD architecture called XSSD. XSSD o oads com- putation in storage to exploit fast NVMs and reduce the redundant data tra c across the I/O bus. XSSD o ers a exible RPC-based programming framework that developers can use for application development on SSD without dealing with the complication of the underlying architecture and communication management. We have built a prototype of XSSD on the BEE3 FPGA prototyping system. We implement various data-intensive applications and achieve speedup and energy ef- ciency of 1.5-8.9 and 1.7-10.27 respectively. This dissertation also compares XSSD with previous work on intelligent storage and intelligent memory. The existing ecosystem and these new enabling technologies make this system more viable than earlier ones.

  5. Non-Dependent and Dependent Daily Cannabis Users Differ in Mental Health but Not Prospective Memory Ability

    OpenAIRE

    Ruth Braidwood; Samantha Mansell; Jon Waldron; Peter G. Rendell; Sunjeev K. Kamboj; H. Valerie Curran

    2018-01-01

    Research suggests that daily cannabis users have impaired memory for past events, but it is not clear whether they are also impaired in prospective memory (PM) for future events. The present study examined PM in daily cannabis users who were either dependent (n = 18) or non-dependent (n = 18), and compared them with non-using controls (n = 18). The effect of future event simulation (FES) on PM performance was also examined. Participants were matched across groups on age, gender, and highest l...

  6. Mental object rotation in Parkinson's disease.

    Science.gov (United States)

    Crucian, Gregory P; Barrett, Anna M; Burks, David W; Riestra, Alonso R; Roth, Heidi L; Schwartz, Ronald L; Triggs, William J; Bowers, Dawn; Friedman, William; Greer, Melvin; Heilman, Kenneth M

    2003-11-01

    Deficits in visual-spatial ability can be associated with Parkinson's disease (PD), and there are several possible reasons for these deficits. Dysfunction in frontal-striatal and/or frontal-parietal systems, associated with dopamine deficiency, might disrupt cognitive processes either supporting (e.g., working memory) or subserving visual-spatial computations. The goal of this study was to assess visual-spatial orientation ability in individuals with PD using the Mental Rotations Test (MRT), along with other measures of cognitive function. Non-demented men with PD were significantly less accurate on this test than matched control men. In contrast, women with PD performed similarly to matched control women, but both groups of women did not perform much better than chance. Further, mental rotation accuracy in men correlated with their executive skills involving mental processing and psychomotor speed. In women with PD, however, mental rotation accuracy correlated negatively with verbal memory, indicating that higher mental rotation performance was associated with lower ability in verbal memory. These results indicate that PD is associated with visual-spatial orientation deficits in men. Women with PD and control women both performed poorly on the MRT, possibly reflecting a floor effect. Although men and women with PD appear to engage different cognitive processes in this task, the reason for the sex difference remains to be elucidated.

  7. Compiling for Novel Scratch Pad Memory based Multicore Architectures for Extreme Scale Computing

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, Aviral

    2016-02-05

    The objective of this proposal is to develop tools and techniques (in the compiler) to manage data of a task and communication among tasks on the scratch pad memory (SPM) of the core, so that any application (a set of tasks) can be executed efficiently on an SPM based manycore architecture.

  8. Computer-Based Working Memory Training in Children with Mild Intellectual Disability

    Science.gov (United States)

    Delavarian, Mona; Bokharaeian, Behrouz; Towhidkhah, Farzad; Gharibzadeh, Shahriar

    2015-01-01

    We designed a working memory (WM) training programme in game framework for mild intellectually disabled students. Twenty-four students participated as test and control groups. The auditory and visual-spatial WM were assessed by primary test, which included computerised Wechsler numerical forward and backward sub-tests and secondary tests, which…

  9. Data systems and computer science space data systems: Onboard memory and storage

    Science.gov (United States)

    Shull, Tom

    1991-01-01

    The topics are presented in viewgraph form and include the following: technical objectives; technology challenges; state-of-the-art assessment; mass storage comparison; SODR drive and system concepts; program description; vertical Bloch line (VBL) device concept; relationship to external programs; and backup charts for memory and storage.

  10. Mentalizing animals

    DEFF Research Database (Denmark)

    Kasperbauer, Tyler Joshua

    2017-01-01

    Ethicists have tended to treat the psychology of attributing mental states to animals as an entirely separate issue from the moral importance of animals’ mental states. In this paper I bring these two issues together. I argue for two theses, one descriptive and one normative. The descriptive thesis...... holds that ordinary human agents use what are generally called phenomenal mental states (e.g., pain and other emotions) to assign moral considerability to animals. I examine recent empirical research on the attribution of phenomenal states and agential states (e.g., memory and intelligence) to argue...... that phenomenal mental states are the primary factor, psychologically, for judging an animal to be morally considerable. I further argue that, given the role of phenomenal states in assigning moral considerability, certain theories in animal ethics will meet significant psychological resistance. The normative...

  11. Gesturing during mental problem solving reduces eye movements, especially for individuals with lower visual working memory capacity

    NARCIS (Netherlands)

    W.T.J.L. Pouw (Wim); M.-F. Mavilidi (Myrto-Foteini); T.A.J.M. van Gog (Tamara); G.W.C. Paas (Fred)

    2016-01-01

    textabstractNon-communicative hand gestures have been found to benefit problem-solving performance. These gestures seem to compensate for limited internal cognitive capacities, such as visual working memory capacity. Yet, it is not clear how gestures might perform this cognitive function. One

  12. Gesturing during mental problem solving reduces eye movements, especially for individuals with lower visual working memory capacity

    NARCIS (Netherlands)

    Pouw, Wim T J L; Mavilidi, Myrto Foteini; van Gog, Tamara; Paas, Fred

    2016-01-01

    Non-communicative hand gestures have been found to benefit problem-solving performance. These gestures seem to compensate for limited internal cognitive capacities, such as visual working memory capacity. Yet, it is not clear how gestures might perform this cognitive function. One hypothesis is that

  13. Cognitive memory.

    Science.gov (United States)

    Widrow, Bernard; Aragon, Juan Carlos

    2013-05-01

    Regarding the workings of the human mind, memory and pattern recognition seem to be intertwined. You generally do not have one without the other. Taking inspiration from life experience, a new form of computer memory has been devised. Certain conjectures about human memory are keys to the central idea. The design of a practical and useful "cognitive" memory system is contemplated, a memory system that may also serve as a model for many aspects of human memory. The new memory does not function like a computer memory where specific data is stored in specific numbered registers and retrieval is done by reading the contents of the specified memory register, or done by matching key words as with a document search. Incoming sensory data would be stored at the next available empty memory location, and indeed could be stored redundantly at several empty locations. The stored sensory data would neither have key words nor would it be located in known or specified memory locations. Sensory inputs concerning a single object or subject are stored together as patterns in a single "file folder" or "memory folder". When the contents of the folder are retrieved, sights, sounds, tactile feel, smell, etc., are obtained all at the same time. Retrieval would be initiated by a query or a prompt signal from a current set of sensory inputs or patterns. A search through the memory would be made to locate stored data that correlates with or relates to the prompt input. The search would be done by a retrieval system whose first stage makes use of autoassociative artificial neural networks and whose second stage relies on exhaustive search. Applications of cognitive memory systems have been made to visual aircraft identification, aircraft navigation, and human facial recognition. Concerning human memory, reasons are given why it is unlikely that long-term memory is stored in the synapses of the brain's neural networks. Reasons are given suggesting that long-term memory is stored in DNA or RNA

  14. Spin-wave interference patterns created by spin-torque nano-oscillators for memory and computation

    International Nuclear Information System (INIS)

    Macia, Ferran; Kent, Andrew D; Hoppensteadt, Frank C

    2011-01-01

    Magnetization dynamics in nanomagnets has attracted broad interest since it was predicted that a dc current flowing through a thin magnetic layer can create spin-wave excitations. These excitations are due to spin momentum transfer, a transfer of spin angular momentum between conduction electrons and the background magnetization, that enables new types of information processing. Here we show how arrays of spin-torque nano-oscillators can create propagating spin-wave interference patterns of use for memory and computation. Memristic transponders distributed on the thin film respond to threshold tunnel magnetoresistance values, thereby allowing spin-wave detection and creating new excitation patterns. We show how groups of transponders create resonant (reverberating) spin-wave interference patterns that may be used for polychronous wave computation and information storage.

  15. An energy efficient and high speed architecture for convolution computing based on binary resistive random access memory

    Science.gov (United States)

    Liu, Chen; Han, Runze; Zhou, Zheng; Huang, Peng; Liu, Lifeng; Liu, Xiaoyan; Kang, Jinfeng

    2018-04-01

    In this work we present a novel convolution computing architecture based on metal oxide resistive random access memory (RRAM) to process the image data stored in the RRAM arrays. The proposed image storage architecture shows performances of better speed-device consumption efficiency compared with the previous kernel storage architecture. Further we improve the architecture for a high accuracy and low power computing by utilizing the binary storage and the series resistor. For a 28 × 28 image and 10 kernels with a size of 3 × 3, compared with the previous kernel storage approach, the newly proposed architecture shows excellent performances including: 1) almost 100% accuracy within 20% LRS variation and 90% HRS variation; 2) more than 67 times speed boost; 3) 71.4% energy saving.

  16. Perspectives on Games, Computers, and Mental Health: Questions about Paradoxes, Evidences, and Challenges.

    Science.gov (United States)

    Desseilles, Martin

    2016-01-01

    In the field of mental health, games and computerized games present questions about paradoxes, evidences, and challenges. This perspective article offers perspectives and personal opinion about these questions, evidences, and challenges with an objective of presenting several ideas and issues in this rapidly developing field. First, games raise some questions in the sense of the paradox between a game and an issue, as well as the paradox of using an amusing game to treat a serious pathology. Second, games also present evidence in the sense that they involve relationships with others, as well as learning, communication, language, emotional regulation, and hedonism. Third, games present challenges, such as the risk of abuse, the critical temporal period that may be limited to childhood, their important influence on sociocognitive learning and the establishment of social norms, and the risk of misuse of games.

  17. A three-dimensional ground-water-flow model modified to reduce computer-memory requirements and better simulate confining-bed and aquifer pinchouts

    Science.gov (United States)

    Leahy, P.P.

    1982-01-01

    The Trescott computer program for modeling groundwater flow in three dimensions has been modified to (1) treat aquifer and confining bed pinchouts more realistically and (2) reduce the computer memory requirements needed for the input data. Using the original program, simulation of aquifer systems with nonrectangular external boundaries may result in a large number of nodes that are not involved in the numerical solution of the problem, but require computer storage. (USGS)

  18. The sensitivity and specificity of subjective memory complaints and the subjective memory rating scale, deterioration cognitive observee, mini-mental state examination, six-item screener and clock drawing test in dementia screening.

    Science.gov (United States)

    Ramlall, S; Chipps, J; Bhigjee, A I; Pillay, B J

    2013-01-01

    The effectiveness of dementia screening depends on the availability of suitable screening tools with good sensitivity and specificity to confidently distinguish normal age-related cognitive decline from dementia. The aim of this study was to evaluate the discriminant validity of 7 screening measures for dementia. A sample of 140 participants aged ≥60 years living in a residential facility for the aged were assessed clinically and assigned caseness for dementia using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revised diagnostic criteria. Sensitivity and specificity of a selection of the following screening measures were tested using receiver operating characteristic (ROC) analysis for individual and combined tests: the Mini-Mental State Examination (MMSE), Six-Item Screener (SIS), Subjective Memory Complaint, Subjective Memory Complaint Clinical (SMCC), Subjective Memory Rating Scale (SMRS), Deterioration Cognitive Observee (DECO) and the Clock Drawing Test (CDT). Using ROC analyses, the SMCC, MMSE and CDT were found to be 'moderately accurate' in screening for dementia with an area under the curve (AUC) >0.70. The AUCs for the SIS (0.526), SMRS (0.661) and DECO (0.687) classified these measures as being 'less accurate'. At recommended cutoff scores, the SMCC had a sensitivity of 90.9% and specificity of 45.7%; the MMSE had a sensitivity of 63.6% and a specificity of 76.0%, and the CDT had a sensitivity of 44.4% and a specificity of 88.9%. Combining the SMCC and MMSE did not improve their predictive power except for a modest increase when using the sequential rule. The SMCC is composed of valid screening questions that have high sensitivity, are simple to administer and ideal for administration at the community or primary health care level as a first level of 'rule-out' screening. The MMSE can be included at a second stage of screening at the general hospital level and the CDT in specialist clinical settings. Sequential use of the

  19. A microscopically motivated constitutive model for shape memory alloys: Formulation, analysis and computations

    Czech Academy of Sciences Publication Activity Database

    Frost, Miroslav; Benešová, B.; Sedlák, P.

    2016-01-01

    Roč. 21, č. 3 (2016), s. 358-382 ISSN 1081-2865 R&D Projects: GA ČR GA13-13616S; GA ČR GAP201/10/0357 Institutional support: RVO:61388998 Keywords : shape memory alloys * constitutive model * generalized standard materials * dissipation * energetic solution Subject RIV: BA - General Mathematics Impact factor: 2.953, year: 2016 http://mms.sagepub.com/content/21/3/358

  20. Circuit-Switched Memory Access in Photonic Interconnection Networks for High-Performance Embedded Computing

    Science.gov (United States)

    2010-07-22

    Memory Systems: Cadle. DRAM, Disk. Morgan Kaufmann , 2007. (2 1) A. Joshi, C. Ballen, Y.-J. Kwon. S . Beamcr, I. Shamim . K. Asano\\’ic, and V...COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d...PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION

  1. Wilfred Own Re-Visited: A Psychoanalytic Reading of War, Memory, and Crisis of Identity in Wilfred Owen’s Poem Mental Cases

    Directory of Open Access Journals (Sweden)

    Ali Güneş

    2017-06-01

    Full Text Available This paper focuses upon the psychoanalytic reading of Wilfred Owen’s poem Mental Cases. In so doing, first, the paper examines how the disturbing experiences and feelings of a tragic event such as a war, torture, rape or murder, which the surviving  victims, civilians and veteran soldiers store in the realm of their unconscious in the Freudian sense, start annoying their feelings after a while. That is, these memories of the past event continuously come later on in life under the troubling influence of recurring flashbacks of the traumatic events, nightmares, irritability, anxiety, and social withdrawal. Eventually these undesirable traumatic past experiences and memories repressed in the unconscious obviously causes individuals to have a kind of psychological disorder which powerfully affects their daily behaviour, life and identity. Secondly, the paper explores this relationship between conscious and unconscious aspect of life, along with the perception of identity, in Owen’s poem Mental Cases, in which the shell-shocked, war-torn veteran soldiers, who experienced and witnessed the shock of World War I and the death of their fellow soldiers, constantly remember the soldiers and innocent civilians who were brutally killed or whom they brutally killed in World War I. Now, these veteran soldiers call back those unhappy times, along with the death of soldiers and civilians, and then suffer in their psyche with a sense of guilt and disappointment: that is, recalling their shocking traumatic war experiences and their killing of many innocent people apparently cripple their vision of life and shatter their identities in the present. Through his representation of these veteran soldiers in such a way, Owen, as in his other poems, artistically and forcefully shows his own reaction, anger and dissatisfaction about the war and its distressing outcome in Mental Cases. Finally, the paper also examines how Owen’s critical view of war and its traumatic

  2. FLASHRAD: A 3D Rad Hard Memory Module For High Performance Space Computers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The computing capabilities of onboard spacecraft are a major limiting factor for accomplishing many classes of future missions. Although technology development...

  3. Mental vision: a computer graphics platform for virtual reality, science and education

    OpenAIRE

    Peternier, Achille

    2009-01-01

    Despite the wide amount of computer graphics frameworks and solutions available for virtual reality, it is still difficult to find a perfect one fitting at the same time the many constraints of research and educational contexts. Advanced functionalities and user-friendliness, rendering speed and portability, or scalability and image quality are opposite characteristics rarely found into a same approach. Furthermore, fruition of virtual reality specific devices like CAVEs or wearable systems i...

  4. Working Memory Influences on Long-Term Memory and Comprehension

    National Research Council Canada - National Science Library

    Radvansky, Gabriel

    2004-01-01

    .... This study looked at how comprehension and memory processing at the mental model level is related to traditional measures of working memory capacity, including the word span, reading span, operation...

  5. FFT transformed quantitative EEG analysis of short term memory load.

    Science.gov (United States)

    Singh, Yogesh; Singh, Jayvardhan; Sharma, Ratna; Talwar, Anjana

    2015-07-01

    The EEG is considered as building block of functional signaling in the brain. The role of EEG oscillations in human information processing has been intensively investigated. To study the quantitative EEG correlates of short term memory load as assessed through Sternberg memory test. The study was conducted on 34 healthy male student volunteers. The intervention consisted of Sternberg memory test, which runs on a version of the Sternberg memory scanning paradigm software on a computer. Electroencephalography (EEG) was recorded from 19 scalp locations according to 10-20 international system of electrode placement. EEG signals were analyzed offline. To overcome the problems of fixed band system, individual alpha frequency (IAF) based frequency band selection method was adopted. The outcome measures were FFT transformed absolute powers in the six bands at 19 electrode positions. Sternberg memory test served as model of short term memory load. Correlation analysis of EEG during memory task was reflected as decreased absolute power in Upper alpha band in nearly all the electrode positions; increased power in Theta band at Fronto-Temporal region and Lower 1 alpha band at Fronto-Central region. Lower 2 alpha, Beta and Gamma band power remained unchanged. Short term memory load has distinct electroencephalographic correlates resembling the mentally stressed state. This is evident from decreased power in Upper alpha band (corresponding to Alpha band of traditional EEG system) which is representative band of relaxed mental state. Fronto-temporal Theta power changes may reflect the encoding and execution of memory task.

  6. Computational perspectives in the history of science: to the memory of Peter Damerow.

    Science.gov (United States)

    Laubichler, Manfred D; Maienschein, Jane; Renn, Jürgen

    2013-03-01

    Computational methods and perspectives can transform the history of science by enabling the pursuit of novel types of questions, dramatically expanding the scale of analysis (geographically and temporally), and offering novel forms of publication that greatly enhance access and transparency. This essay presents a brief summary of a computational research system for the history of science, discussing its implications for research, education, and publication practices and its connections to the open-access movement and similar transformations in the natural and social sciences that emphasize big data. It also argues that computational approaches help to reconnect the history of science to individual scientific disciplines.

  7. Novel Kinds of Random Access Memory and New Vulnerabilities of Computer Aids based on Them

    Directory of Open Access Journals (Sweden)

    Alexander Mihaylovich Korotin

    2014-09-01

    Full Text Available The article discusses vulnerabilities of computer aids based on existing RAM and mechanisms for restricting exploitation of such vulnerabilities. In addition, the article discusses features and work methods of different RAM.

  8. Parallel statistical image reconstruction for cone-beam x-ray CT on a shared memory computation platform

    International Nuclear Information System (INIS)

    Kole, J S; Beekman, F J

    2005-01-01

    Statistical reconstruction methods offer possibilities of improving image quality as compared to analytical methods, but current reconstruction times prohibit routine clinical applications. To reduce reconstruction times we have parallelized a statistical reconstruction algorithm for cone-beam x-ray CT, the ordered subset convex algorithm (OSC), and evaluated it on a shared memory computer. Two different parallelization strategies were developed: one that employs parallelism by computing the work for all projections within a subset in parallel, and one that divides the total volume into parts and processes the work for each sub-volume in parallel. Both methods are used to reconstruct a three-dimensional mathematical phantom on two different grid densities. The reconstructed images are binary identical to the result of the serial (non-parallelized) algorithm. The speed-up factor equals approximately 30 when using 32 to 40 processors, and scales almost linearly with the number of cpus for both methods. The huge reduction in computation time allows us to apply statistical reconstruction to clinically relevant studies for the first time

  9. Efficient implementation of multidimensional fast fourier transform on a distributed-memory parallel multi-node computer

    Science.gov (United States)

    Bhanot, Gyan V [Princeton, NJ; Chen, Dong [Croton-On-Hudson, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

    2012-01-10

    The present in invention is directed to a method, system and program storage device for efficiently implementing a multidimensional Fast Fourier Transform (FFT) of a multidimensional array comprising a plurality of elements initially distributed in a multi-node computer system comprising a plurality of nodes in communication over a network, comprising: distributing the plurality of elements of the array in a first dimension across the plurality of nodes of the computer system over the network to facilitate a first one-dimensional FFT; performing the first one-dimensional FFT on the elements of the array distributed at each node in the first dimension; re-distributing the one-dimensional FFT-transformed elements at each node in a second dimension via "all-to-all" distribution in random order across other nodes of the computer system over the network; and performing a second one-dimensional FFT on elements of the array re-distributed at each node in the second dimension, wherein the random order facilitates efficient utilization of the network thereby efficiently implementing the multidimensional FFT. The "all-to-all" re-distribution of array elements is further efficiently implemented in applications other than the multidimensional FFT on the distributed-memory parallel supercomputer.

  10. Efficient implementation of a multidimensional fast fourier transform on a distributed-memory parallel multi-node computer

    Science.gov (United States)

    Bhanot, Gyan V [Princeton, NJ; Chen, Dong [Croton-On-Hudson, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

    2008-01-01

    The present in invention is directed to a method, system and program storage device for efficiently implementing a multidimensional Fast Fourier Transform (FFT) of a multidimensional array comprising a plurality of elements initially distributed in a multi-node computer system comprising a plurality of nodes in communication over a network, comprising: distributing the plurality of elements of the array in a first dimension across the plurality of nodes of the computer system over the network to facilitate a first one-dimensional FFT; performing the first one-dimensional FFT on the elements of the array distributed at each node in the first dimension; re-distributing the one-dimensional FFT-transformed elements at each node in a second dimension via "all-to-all" distribution in random order across other nodes of the computer system over the network; and performing a second one-dimensional FFT on elements of the array re-distributed at each node in the second dimension, wherein the random order facilitates efficient utilization of the network thereby efficiently implementing the multidimensional FFT. The "all-to-all" re-distribution of array elements is further efficiently implemented in applications other than the multidimensional FFT on the distributed-memory parallel supercomputer.

  11. Non-Dependent and Dependent Daily Cannabis Users Differ in Mental Health but Not Prospective Memory Ability

    Directory of Open Access Journals (Sweden)

    Ruth Braidwood

    2018-03-01

    Full Text Available Research suggests that daily cannabis users have impaired memory for past events, but it is not clear whether they are also impaired in prospective memory (PM for future events. The present study examined PM in daily cannabis users who were either dependent (n = 18 or non-dependent (n = 18, and compared them with non-using controls (n = 18. The effect of future event simulation (FES on PM performance was also examined. Participants were matched across groups on age, gender, and highest level of education. The virtual week (VW was used to objectively assess PM abilities, both at baseline and following FES. Other measures used were: cannabis use variables, immediate and delayed prose recall, phonemic and category fluency, spot-the-word test (premorbid intelligence, Beck Depression Inventory, Beck Anxiety Inventory, and a measure of schizotypy (Oxford-Liverpool Inventory of Feelings and Experiences: unusual experiences subscale. No group differences were found in PM performance on the VW, and FES did not improve PM performance in any group. Dependent cannabis users scored higher on depression, anxiety, and schizotypy than both other groups with non-dependent cannabis users scoring at a similar level to controls. There were no group differences in alcohol use. Findings suggest that when carefully matched on baseline variables, and not differing in premorbid IQ or alcohol use, young, near-daily cannabis users do not differ from non-using controls in PM performance.

  12. Fencing network direct memory access data transfers in a parallel active messaging interface of a parallel computer

    Science.gov (United States)

    Blocksome, Michael A.; Mamidala, Amith R.

    2015-07-07

    Fencing direct memory access (`DMA`) data transfers in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI including data communications endpoints, each endpoint including specifications of a client, a context, and a task, the endpoints coupled for data communications through the PAMI and through DMA controllers operatively coupled to a deterministic data communications network through which the DMA controllers deliver data communications deterministically, including initiating execution through the PAMI of an ordered sequence of active DMA instructions for DMA data transfers between two endpoints, effecting deterministic DMA data transfers through a DMA controller and the deterministic data communications network; and executing through the PAMI, with no FENCE accounting for DMA data transfers, an active FENCE instruction, the FENCE instruction completing execution only after completion of all DMA instructions initiated prior to execution of the FENCE instruction for DMA data transfers between the two endpoints.

  13. Parallelization of MCNP 4, a Monte Carlo neutron and photon transport code system, in highly parallel distributed memory type computer

    International Nuclear Information System (INIS)

    Masukawa, Fumihiro; Takano, Makoto; Naito, Yoshitaka; Yamazaki, Takao; Fujisaki, Masahide; Suzuki, Koichiro; Okuda, Motoi.

    1993-11-01

    In order to improve the accuracy and calculating speed of shielding analyses, MCNP 4, a Monte Carlo neutron and photon transport code system, has been parallelized and measured of its efficiency in the highly parallel distributed memory type computer, AP1000. The code has been analyzed statically and dynamically, then the suitable algorithm for parallelization has been determined for the shielding analysis functions of MCNP 4. This includes a strategy where a new history is assigned to the idling processor element dynamically during the execution. Furthermore, to avoid the congestion of communicative processing, the batch concept, processing multi-histories by a unit, has been introduced. By analyzing a sample cask problem with 2,000,000 histories by the AP1000 with 512 processor elements, the 82 % of parallelization efficiency is achieved, and the calculational speed has been estimated to be around 50 times as fast as that of FACOM M-780. (author)

  14. Computer Modeling of Sand Transport on Mars Using a Compart-Mentalized Fluids Algorithm (CFA)

    Science.gov (United States)

    Marshall, J.; Stratton, D.

    1999-01-01

    It has been postulated that aeolian transport on Mars may be significantly different from that on Earth. From laboratory experiments simulating martian grain transport [2], it has been observed that (saltating) grains striking the bed can cause hundreds of secondary reptation trajectories when impact occurs at speeds postulated for Mars. Some of the ballistically induced trajectories "die ouf' and effectively join the ranks on the creep population that is merely nudged along by impact. Many of the induced reptation trajectories, however, are sufficiently high for the grains to become part of the saltation load (it is irrelevant to the boundary layer how a grain attained its initial lift force). When these grains, in turn, strike the surface, they too are capable of inducing more reptating grains. This cascading effect has been discussed in connection with terrestrial aeolian transport in an attempt to dispel the notion that sand motion is divisible only into creep and saltation loads. On Earth, only a few grains are splashed by impact. On Mars, it may be hundreds. We developed a computer model to address this phenomenon because there are some important ramifications: First, this ratio may mean that martian aeolian transport is dominated by reptation flux rather than saltation. On Earth, the flux would be a roughly balanced mixture between reptation/creep and saltation. On Venus, there would be no transport other than by saltation. In other words, an understanding of planetary aeolian processes may not be necessarily understood by extrapolating from the "Earth case", with only gravity and atmospheric density/viscosity being considered as variables. Second, the reptation flux on Mars may be self sustaining, so that little input is required by the wind once transport has been initiated. The number of grains saturating the boundary layer near the bed may mean that average grain speed on Mars might conceivably be less than that on Earth. This would say much for models

  15. Neuron class-specific requirements for Fragile X Mental Retardation Protein in critical period development of calcium signaling in learning and memory circuitry.

    Science.gov (United States)

    Doll, Caleb A; Broadie, Kendal

    2016-05-01

    Neural circuit optimization occurs through sensory activity-dependent mechanisms that refine synaptic connectivity and information processing during early-use developmental critical periods. Fragile X Mental Retardation Protein (FMRP), the gene product lost in Fragile X syndrome (FXS), acts as an activity sensor during critical period development, both as an RNA-binding translation regulator and channel-binding excitability regulator. Here, we employ a Drosophila FXS disease model to assay calcium signaling dynamics with a targeted transgenic GCaMP reporter during critical period development of the mushroom body (MB) learning/memory circuit. We find FMRP regulates depolarization-induced calcium signaling in a neuron-specific manner within this circuit, suppressing activity-dependent calcium transients in excitatory cholinergic MB input projection neurons and enhancing calcium signals in inhibitory GABAergic MB output neurons. Both changes are restricted to the developmental critical period and rectified at maturity. Importantly, conditional genetic (dfmr1) rescue of null mutants during the critical period corrects calcium signaling defects in both neuron classes, indicating a temporally restricted FMRP requirement. Likewise, conditional dfmr1 knockdown (RNAi) during the critical period replicates constitutive null mutant defects in both neuron classes, confirming cell-autonomous requirements for FMRP in developmental regulation of calcium signaling dynamics. Optogenetic stimulation during the critical period enhances depolarization-induced calcium signaling in both neuron classes, but this developmental change is eliminated in dfmr1 null mutants, indicating the activity-dependent regulation requires FMRP. These results show FMRP shapes neuron class-specific calcium signaling in excitatory vs. inhibitory neurons in developing learning/memory circuitry, and that FMRP mediates activity-dependent regulation of calcium signaling specifically during the early

  16. Memristor-based ternary content addressable memory (mTCAM) for data-intensive computing

    International Nuclear Information System (INIS)

    Zheng, Le; Shin, Sangho; Steve Kang, Sung-Mo

    2014-01-01

    A memristor-based ternary content addressable memory (mTCAM) is presented. Each mTCAM cell, consisting of five transistors and two memristors to store and search for ternary data, is capable of remarkable nonvolatility and higher storage density than conventional CMOS-based TCAMs. Each memristor in the cell can be programmed individually such that high impedance is always present between searchlines to reduce static energy consumption. A unique two-step write scheme offers reliable and energy-efficient write operations. The search voltage is designed to ensure optimum sensing margins with the presence of variations in memristor devices. Simulations of the proposed mTCAM demonstrate functionalities in write and search modes, as well as a search delay of 2 ns and a search of 0.99 fJ/bit/search for a word width of 128 bits. (paper)

  17. A Computational Account of Children's Analogical Reasoning: Balancing Inhibitory Control in Working Memory and Relational Representation

    Science.gov (United States)

    Morrison, Robert G.; Doumas, Leonidas A. A.; Richland, Lindsey E.

    2011-01-01

    Theories accounting for the development of analogical reasoning tend to emphasize either the centrality of relational knowledge accretion or changes in information processing capability. Simulations in LISA (Hummel & Holyoak, 1997, 2003), a neurally inspired computer model of analogical reasoning, allow us to explore how these factors may…

  18. Effects of exercise and horticultural intervention on the brain and mental health in older adults with depressive symptoms and memory problems: study protocol for a randomized controlled trial [UMIN000018547].

    Science.gov (United States)

    Makizako, Hyuma; Tsutsumimoto, Kota; Doi, Takehiko; Hotta, Ryo; Nakakubo, Sho; Liu-Ambrose, Teresa; Shimada, Hiroyuki

    2015-11-04

    Depressive symptoms and memory problems are significant risk factors for dementia. Exercise can reduce depressive symptoms and improve cognitive function in older people. In addition, the benefits of horticultural activity on physical and mental well-being have been demonstrated in people with dementia. Although evidence of such non-pharmacological interventions is mounting, no studies have examined whether physical exercise and horticultural activity exert a positive impact on brain and mental health (e.g., depressive symptoms) in non-demented older adults at high risk of cognitive impairment and depression. Therefore, we propose a randomized controlled trial to assess the efficacy and efficiency of physical exercise and horticultural activity in improving brain and mental health in community-dwelling older adults with memory problems and depressive symptoms. The 20-week randomized controlled trial will include 90 community-dwelling adults aged 65 years or older with memory problems and depressive symptoms. Participants will be randomized to one of three experiments: exercise, horticultural activity, or educational control group, using a 1:1:1 allocation ratio. The combined exercise program and horticultural activity program will consist of 20 weekly 90-minute sessions. Participants in the exercise group will practice aerobic exercise, muscle strength training, postural balance retraining, and dual-task training. The horticultural activity program will include crop-related activities, such as field cultivation, growing, and harvesting. Participants in the educational control group will attend two 90-minute educational classes during the 6-month trial period. Depressive symptoms and memory performance will be measured by the Geriatric Depression Scale-15, and the Logical Memory subtests of the Wechsler Memory Scale-Revised will be used to measure depressive symptoms and memory performance as primary outcomes, at baseline (prior to randomization), immediately

  19. Blood leakage detection during dialysis therapy based on fog computing with array photocell sensors and heteroassociative memory model.

    Science.gov (United States)

    Wu, Jian-Xing; Huang, Ping-Tzan; Lin, Chia-Hung; Li, Chien-Ming

    2018-02-01

    Blood leakage and blood loss are serious life-threatening complications occurring during dialysis therapy. These events have been of concerns to both healthcare givers and patients. More than 40% of adult blood volume can be lost in just a few minutes, resulting in morbidities and mortality. The authors intend to propose the design of a warning tool for the detection of blood leakage/blood loss during dialysis therapy based on fog computing with an array of photocell sensors and heteroassociative memory (HAM) model. Photocell sensors are arranged in an array on a flexible substrate to detect blood leakage via the resistance changes with illumination in the visible spectrum of 500-700 nm. The HAM model is implemented to design a virtual alarm unit using electricity changes in an embedded system. The proposed warning tool can indicate the risk level in both end-sensing units and remote monitor devices via a wireless network and fog/cloud computing. The animal experimental results (pig blood) will demonstrate the feasibility.

  20. Blood leakage detection during dialysis therapy based on fog computing with array photocell sensors and heteroassociative memory model

    Science.gov (United States)

    Wu, Jian-Xing; Huang, Ping-Tzan; Li, Chien-Ming

    2018-01-01

    Blood leakage and blood loss are serious life-threatening complications occurring during dialysis therapy. These events have been of concerns to both healthcare givers and patients. More than 40% of adult blood volume can be lost in just a few minutes, resulting in morbidities and mortality. The authors intend to propose the design of a warning tool for the detection of blood leakage/blood loss during dialysis therapy based on fog computing with an array of photocell sensors and heteroassociative memory (HAM) model. Photocell sensors are arranged in an array on a flexible substrate to detect blood leakage via the resistance changes with illumination in the visible spectrum of 500–700 nm. The HAM model is implemented to design a virtual alarm unit using electricity changes in an embedded system. The proposed warning tool can indicate the risk level in both end-sensing units and remote monitor devices via a wireless network and fog/cloud computing. The animal experimental results (pig blood) will demonstrate the feasibility. PMID:29515815

  1. Total Mini-Mental State Examination score and regional cerebral blood flow using Z score imaging and automated ROI analysis software in subjects with memory impairment

    International Nuclear Information System (INIS)

    Ikeda, Eiji; Shiozaki, Kazumasa; Takahashi, Nobukazu; Togo, Takashi; Odawara, Toshinari; Oka, Takashi; Inoue, Tomio; Hirayasu, Yoshio

    2008-01-01

    The Mini-Mental State Examination (MMSE) is considered a useful supplementary method to diagnose dementia and evaluate the severity of cognitive disturbance. However, the region of the cerebrum that correlates with the MMSE score is not clear. Recently, a new method was developed to analyze regional cerebral blood flow (rCBF) using a Z score imaging system (eZIS). This system shows changes of rCBF when compared with a normal database. In addition, a three-dimensional stereotaxic region of interest (ROI) template (3DSRT), fully automated ROI analysis software was developed. The objective of this study was to investigate the correlation between rCBF changes and total MMSE score using these new methods. The association between total MMSE score and rCBF changes was investigated in 24 patients (mean age±standard deviation (SD) 71.5±9.2 years; 6 men and 18 women) with memory impairment using eZIS and 3DSRT. Step-wise multiple regression analysis was used for multivariate analysis, with the total MMSE score as the dependent variable and rCBF change in 24 areas as the independent variable. Total MMSE score was significantly correlated only with the reduction of left hippocampal perfusion but not with right (P<0.01). Total MMSE score is an important indicator of left hippocampal function. (author)

  2. The Mini-Cog, Clock Drawing Test, and the Mini-Mental State Examination in a German memory clinic: specificity of separation dementia from depression.

    Science.gov (United States)

    Milian, Monika; Leiherr, Anna-Maria; Straten, Guido; Müller, Stephan; Leyhe, Thomas; Eschweiler, Gerhard W

    2013-01-01

    The aim of this study was to assess the specificities of the Mini-Cog, the Clock Drawing Test (CDT), and the Mini-Mental State Examination (MMSE) against depression and healthy controls in a German Memory Clinic. Furthermore, we analyzed the specificities of all three screening instruments in dependence of actual depression severity. Data from 142 depressed elderly, 438 dementia patients, and 64 healthy controls were retrospectively analyzed. The CDT and an extraction of the three-item recall of the MMSE were used to constitute the Mini-Cog algorithm. Depression severity was rated by either the Beck Depression Inventory (BDI) or the Geriatric Depression Scale (GDS) depending on the age of the patients. The Mini-Cog achieved a specificity of 79.6% against depressed elderly and 100.0% against healthy subjects (p Mini-Cog and the CDT, but also showed the lowest sensitivity for the detection of dementia. Surprisingly, the depression severity had no effect on the specificity of the Mini-Cog and the CDT, only the MMSE was susceptible for the depression severity. Although the MMSE showed higher specificities, the weighting between the sensitivities and specificities in all tests prove again the Mini-Cog as a short, valid, and sensitive screening tool.

  3. Using mental visual imagery to improve autobiographical memory and episodic future thinking in relapsing-remitting multiple sclerosis patients: A randomised-controlled trial study.

    Science.gov (United States)

    Ernst, Alexandra; Blanc, Frédéric; De Seze, Jérôme; Manning, Liliann

    2015-01-01

    The co-occurrence of autobiographical memory (AM) and episodic future thinking (EFT) impairment has been documented in relapsing-remitting multiple sclerosis (RR-MS) patients. On these bases, we aimed at probing the efficacy of a mental visual imagery (MVI)-based facilitation programme on AM and EFT functioning in the context of a randomised-controlled trial study in RR-MS patients. Using the Autobiographical Interview (AI), 40 patients presenting with an AM/EFT impairment were randomly assigned in three groups: (i) the experimental (n = 17), who followed the MVI programme, (ii) the verbal control (n = 10), who followed a sham verbal programme, and (iii) the stability groups (n = 13), who underwent the AM/EFT test twice, with no intervention in between. AI's second assessment scores showed a significant improvement of AM and EFT performance only for the experimental group, with a long-term robustness of treatment benefits. The control and stability groups' results ruled out nursing and test learning effects as explanations of AM/EFT improvement. These benefits were corroborated by the patients' comments, which indicated an effective MVI strategy transfer to daily life. Our results suggest that the MVI programme tackles a common cognitive process of scene construction present in AM and EFT.

  4. Change of short-term memory effect in acute ischemic ventricular myocardium: a computational study.

    Science.gov (United States)

    Mei, Xi; Wang, Jing; Zhang, Hong; Liu, Zhi-cheng; Zhang, Zhen-xi

    2014-02-01

    The ionic mechanism of change in short-term memory (STM) during acute myocardial ischemia has not been well understood. In this paper, an advanced guinea pig ventricular model developed by Luo and Rudy was used to investigate STM property of ischemic ventricular myocardium. STM response was calculated by testing the time to reach steady-state action potential duration (APD) after an abrupt shortening of basic cycling length (BCL) in the pacing protocol. Electrical restitution curves (RCs), which can simultaneously visualize multiple aspects of APD restitution and STM, were obtained from dynamic and local S1S2 restitution portrait (RP), which consist of a longer interval stimulus (S1) and a shorter interval stimulus (S2). The angle between dynamic RC and local S1S2 RC reflects the amount of STM. Our results indicated that compared with control (normal) condition, time constant of STM response in the ischemic condition decreased significantly. Meanwhile the angle which reflects STM amount is less in ischemic model than that in control model. By tracking the effect of ischemia on intracellular ion concentration and membrane currents, we declared that changes in membrane currents caused by ischemia exert subtle influences on STM; it is only the decline of intracellular calcium concentration that give rise to the most decrement of STM. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Improving Outcome of Psychosocial Treatments by Enhancing Memory and Learning

    Science.gov (United States)

    Harvey, Allison G.; Lee, Jason; Williams, Joseph; Hollon, Steven D.; Walker, Matthew P.; Thompson, Monique A.; Smith, Rita

    2014-01-01

    Mental disorders are prevalent and lead to significant impairment. Progress toward establishing treatments has been good. However, effect sizes are small to moderate, gains may not persist, and many patients derive no benefit. Our goal is to highlight the potential for empirically-supported psychosocial treatments to be improved by incorporating insights from cognitive psychology and research on education. Our central question is: If it were possible to improve memory for content of sessions of psychosocial treatments, would outcome substantially improve? This question arises from five lines of evidence: (a) mental illness is often characterized by memory impairment, (b) memory impairment is modifiable, (c) psychosocial treatments often involve the activation of emotion, (d) emotion can bias memory and (e) memory for psychosocial treatment sessions is poor. Insights from scientific knowledge on learning and memory are leveraged to derive strategies for a transdiagnostic and transtreatment cognitive support intervention. These strategies can be applied within and between sessions and to interventions delivered via computer, the internet and text message. Additional novel pathways to improving memory include improving sleep, engaging in exercise and imagery. Given that memory processes change across the lifespan, services to children and older adults may benefit from cognitive support. PMID:25544856

  6. Modeling Mental Speed: Decomposing Response Time Distributions in Elementary Cognitive Tasks and Correlations with Working Memory Capacity and Fluid Intelligence

    Directory of Open Access Journals (Sweden)

    Florian Schmitz

    2016-10-01

    Full Text Available Previous research has shown an inverse relation between response times in elementary cognitive tasks and intelligence, but findings are inconsistent as to which is the most informative score. We conducted a study (N = 200 using a battery of elementary cognitive tasks, working memory capacity (WMC paradigms, and a test of fluid intelligence (gf. Frequently used candidate scores and model parameters derived from the response time (RT distribution were tested. Results confirmed a clear correlation of mean RT with WMC and to a lesser degree with gf. Highly comparable correlations were obtained for alternative location measures with or without extreme value treatment. Moderate correlations were found as well for scores of RT variability, but they were not as strong as for mean RT. Additionally, there was a trend towards higher correlations for slow RT bands, as compared to faster RT bands. Clearer evidence was obtained in an ex-Gaussian decomposition of the response times: the exponential component was selectively related to WMC and gf in easy tasks, while mean response time was additionally predictive in the most complex tasks. The diffusion model parsimoniously accounted for these effects in terms of individual differences in drift rate. Finally, correlations of model parameters as trait-like dispositions were investigated across different tasks, by correlating parameters of the diffusion and the ex-Gaussian model with conventional RT and accuracy scores.

  7. Mental Mechanisms for Topics Identification

    Directory of Open Access Journals (Sweden)

    Louis Massey

    2014-01-01

    Full Text Available Topics identification (TI is the process that consists in determining the main themes present in natural language documents. The current TI modeling paradigm aims at acquiring semantic information from statistic properties of large text datasets. We investigate the mental mechanisms responsible for the identification of topics in a single document given existing knowledge. Our main hypothesis is that topics are the result of accumulated neural activation of loosely organized information stored in long-term memory (LTM. We experimentally tested our hypothesis with a computational model that simulates LTM activation. The model assumes activation decay as an unavoidable phenomenon originating from the bioelectric nature of neural systems. Since decay should negatively affect the quality of topics, the model predicts the presence of short-term memory (STM to keep the focus of attention on a few words, with the expected outcome of restoring quality to a baseline level. Our experiments measured topics quality of over 300 documents with various decay rates and STM capacity. Our results showed that accumulated activation of loosely organized information was an effective mental computational commodity to identify topics. It was furthermore confirmed that rapid decay is detrimental to topics quality but that limited capacity STM restores quality to a baseline level, even exceeding it slightly.

  8. Three-dimensional magnetic field computation on a distributed memory parallel processor

    International Nuclear Information System (INIS)

    Barion, M.L.

    1990-01-01

    The analysis of three-dimensional magnetic fields by finite element methods frequently proves too onerous a task for the computing resource on which it is attempted. When non-linear and transient effects are included, it may become impossible to calculate the field distribution to sufficient resolution. One approach to this problem is to exploit the natural parallelism in the finite element method via parallel processing. This paper reports on an implementation of a finite element code for non-linear three-dimensional low-frequency magnetic field calculation on Intel's iPSC/2

  9. Visual Memories Bypass Normalization.

    Science.gov (United States)

    Bloem, Ilona M; Watanabe, Yurika L; Kibbe, Melissa M; Ling, Sam

    2018-05-01

    How distinct are visual memory representations from visual perception? Although evidence suggests that briefly remembered stimuli are represented within early visual cortices, the degree to which these memory traces resemble true visual representations remains something of a mystery. Here, we tested whether both visual memory and perception succumb to a seemingly ubiquitous neural computation: normalization. Observers were asked to remember the contrast of visual stimuli, which were pitted against each other to promote normalization either in perception or in visual memory. Our results revealed robust normalization between visual representations in perception, yet no signature of normalization occurring between working memory stores-neither between representations in memory nor between memory representations and visual inputs. These results provide unique insight into the nature of visual memory representations, illustrating that visual memory representations follow a different set of computational rules, bypassing normalization, a canonical visual computation.

  10. Assessment of the anterior loop of mental nerve in an Iranian population using cone beam computed tomography scan

    Directory of Open Access Journals (Sweden)

    Mitra Karbasi Kheir

    2017-01-01

    Conclusion: Great care is required when placing implants in proximity to mental foramen to avoid anterior loop injury. Because of the variations of anterior loop length in each patient, a fixed distance anterior to the mental foramen is not safe, and the anterior loop length should be determined for each individual. The use of CBCT provides accurate measurements of the length of anterior loop.

  11. Effect of Addiction to Computer Games on Physical and Mental Health of Female and Male Students of Guidance School in City of Isfahan

    OpenAIRE

    Zamani, Eshrat; Chashmi, Maliheh; Hedayati, Nasim

    2009-01-01

    Background: This study aimed to investigate the effects of addiction to computer games on physical and mental health of students. Methods: The study population includes all students in the second year of public guidance schools in the city of Isfahan in the educational year of 2009-2010. The sample size includes 564 students selected by multiple steps stratified sampling. Dependent variables include general health in dimensions of physical health, anxiety and sleeplessness and impaired social...

  12. Human performance across decision making, selective attention, and working memory tasks: Experimental data and computer simulations

    Directory of Open Access Journals (Sweden)

    Andrea Stocco

    2018-04-01

    Full Text Available This article describes the data analyzed in the paper “Individual differences in the Simon effect are underpinned by differences in the competitive dynamics in the basal ganglia: An experimental verification and a computational model” (Stocco et al., 2017 [1]. The data includes behavioral results from participants performing three cognitive tasks (Probabilistic Stimulus Selection (Frank et al., 2004 [2], Simon task (Craft and Simon, 1970 [3], and Automated Operation Span (Unsworth et al., 2005 [4], as well as simulationed traces generated by a computational neurocognitive model that accounts for individual variations in human performance across the tasks. The experimental data encompasses individual data files (in both preprocessed and native output format as well as group-level summary files. The simulation data includes the entire model code, the results of a full-grid search of the model's parameter space, and the code used to partition the model space and parallelize the simulations. Finally, the repository includes the R scripts used to carry out the statistical analyses reported in the original paper.

  13. Human performance across decision making, selective attention, and working memory tasks: Experimental data and computer simulations.

    Science.gov (United States)

    Stocco, Andrea; Yamasaki, Brianna L; Prat, Chantel S

    2018-04-01

    This article describes the data analyzed in the paper "Individual differences in the Simon effect are underpinned by differences in the competitive dynamics in the basal ganglia: An experimental verification and a computational model" (Stocco et al., 2017) [1]. The data includes behavioral results from participants performing three cognitive tasks (Probabilistic Stimulus Selection (Frank et al., 2004) [2], Simon task (Craft and Simon, 1970) [3], and Automated Operation Span (Unsworth et al., 2005) [4]), as well as simulationed traces generated by a computational neurocognitive model that accounts for individual variations in human performance across the tasks. The experimental data encompasses individual data files (in both preprocessed and native output format) as well as group-level summary files. The simulation data includes the entire model code, the results of a full-grid search of the model's parameter space, and the code used to partition the model space and parallelize the simulations. Finally, the repository includes the R scripts used to carry out the statistical analyses reported in the original paper.

  14. Main Memory DBMS

    NARCIS (Netherlands)

    P.A. Boncz (Peter); L. Liu (Lei); M. Tamer Özsu

    2008-01-01

    htmlabstractA main memory database system is a DBMS that primarily relies on main memory for computer data storage. In contrast, normal database management systems employ hard disk based persisntent storage.

  15. Computational design of precipitation-strengthened titanium-nickel-based shape memory alloys

    Science.gov (United States)

    Bender, Matthew D.

    Motivated by performance requirements of future medical stent applications, experimental research addresses the design of novel TiNi-based, superelastic shape-memory alloys employing nanoscale precipitation strengthening to minimize accommodation slip for cyclic stability and to increase output stress capability for smaller devices. Using a thermodynamic database describing the B2 and L21 phases in the Al-Ni-Ti-Zr system, Thermo-Calc software was used to assist modeling the evolution of phase composition during 600°C isothermal evolution of coherent L21 Heusler phase precipitation from supersaturated TiNi-based B2 phase matrix in an alloy experimentally characterized by atomic-scale Local Electrode Atom Probe (LEAP) microanalysis. Based on measured evolution of the alloy hardness (under conditions stable against martensitic transformation) a model for the combined effects of solid solution strengthening and precipitation strengthening was calibrated, and the optimum particle size for efficient strengthening was identified. Thermodynamic modeling of the evolution of measured phase fractions and compositions identified the interfacial capillary energy enabling thermodynamic design of alloy microstructure with the optimal strengthening particle size. Extension of alloy designs to incorporate Pt and Pd for reducing Ni content, enhancing radiopacity, and improving manufacturability were considered using measured Pt and Pd B2/L2 1 partitioning coefficients. After determining that Pt partitioning greatly increases interphase misfit, full attention was devoted to Pd alloy designs. A quantitative approach to radiopacity was employed using mass attenuation as a metric. Radiopacity improvements were also qualitatively observed using x-ray fluoroscopy. Transformation temperatures were experimentally measured as a function of Al and Pd content. Redlich-Kister polynomial modeling was utilized for the dependence of transformation reversion Af temperature on B2 matrix phase

  16. Effect of addiction to computer games on physical and mental health of female and male students of guidance school in city of isfahan.

    Science.gov (United States)

    Zamani, Eshrat; Chashmi, Maliheh; Hedayati, Nasim

    2009-01-01

    This study aimed to investigate the effects of addiction to computer games on physical and mental health of students. The study population includes all students in the second year of public guidance schools in the city of Isfahan in the educational year of 2009-2010. The sample size includes 564 students selected by multiple steps stratified sampling. Dependent variables include general health in dimensions of physical health, anxiety and sleeplessness and impaired social functioning. Data were collected using General Health Questionnaire (GHQ-28) scale and a questionnaire on addiction to computer games. Pearson's correlation coefficient and structural model were used for data analysis. There was a significant positive correlation between students' computer games addiction and their physical and mental health in dimensions of physical health, anxiety and sleeplessness There was a significant negative relationship between addictions to computer games and impaired social functioning. The results of this study are in agreement with the findings of other studies around the world. As the results show, addiction to computer games affects various dimensions of health and increases physical problems, anxiety and depression, while decreases social functioning disorder.

  17. Ab Initio Molecular-Dynamics Simulation of Neuromorphic Computing in Phase-Change Memory Materials.

    Science.gov (United States)

    Skelton, Jonathan M; Loke, Desmond; Lee, Taehoon; Elliott, Stephen R

    2015-07-08

    We present an in silico study of the neuromorphic-computing behavior of the prototypical phase-change material, Ge2Sb2Te5, using ab initio molecular-dynamics simulations. Stepwise changes in structural order in response to temperature pulses of varying length and duration are observed, and a good reproduction of the spike-timing-dependent plasticity observed in nanoelectronic synapses is demonstrated. Short above-melting pulses lead to instantaneous loss of structural and chemical order, followed by delayed partial recovery upon structural relaxation. We also investigate the link between structural order and electrical and optical properties. These results pave the way toward a first-principles understanding of phase-change physics beyond binary switching.

  18. Number sense or working memory? The effect of two computer-based trainings on mathematical skills in elementary school.

    Science.gov (United States)

    Kuhn, Jörg-Tobias; Holling, Heinz

    2014-01-01

    Research on the improvement of elementary school mathematics has shown that computer-based training of number sense (e.g., processing magnitudes or locating numbers on the number line) can lead to substantial achievement gains in arithmetic skills. Recent studies, however, have highlighted that training domain-general cognitive abilities (e.g., working memory [WM]) may also improve mathematical achievement. This study addressed the question of whether a training of domain-specific number sense skills or domain-general WM abilities is more appropriate for improving mathematical abilities in elementary school. Fifty-nine children (M age = 9 years, 32 girls and 27 boys) received either a computer-based, adaptive training of number sense (n = 20), WM skills (n = 19), or served as a control group (n = 20). The training duration was 20 min per day for 15 days. Before and after training, we measured mathematical ability using a curriculum-based math test, as well as spatial WM. For both training groups, we observed substantial increases in the math posttest compared to the control group (d = .54 for number sense skills training, d = .57 for WM training, respectively). Whereas the number sense group showed significant gains in arithmetical skills, the WM training group exhibited marginally significant gains in word problem solving. However, no training group showed significant posttest gains on the spatial WM task. Results indicate that a short training of either domain-specific or domain-general skills may result in reliable short-term training gains in math performance, although no stable training effects were found in the spatial WM task.

  19. Cognitive and Neural Plasticity in Older Adults’ Prospective Memory Following Training with the Virtual Week Computer Game

    Directory of Open Access Journals (Sweden)

    Nathan S Rose

    2015-10-01

    Full Text Available Prospective memory (PM – the ability to remember and successfully execute our intentions and planned activities – is critical for functional independence and declines with age, yet few studies have attempted to train PM in older adults. We developed a PM training program using the Virtual Week computer game. Trained participants played the game in twelve, 1-hour sessions over one month. Measures of neuropsychological functions, lab-based PM, event-related potentials (ERPs during performance on a lab-based PM task, instrumental activities of daily living, and real-world PM were assessed before and after training. Performance was compared to both no-contact and active (music training control groups. PM on the Virtual Week game dramatically improved following training relative to controls, suggesting PM plasticity is preserved in older adults. Relative to control participants, training did not produce reliable transfer to laboratory-based tasks, but was associated with a reduction of an ERP component (sustained negativity over occipito-parietal cortex associated with processing PM cues, indicative of more automatic PM retrieval. Most importantly, training produced far transfer to real-world outcomes including improvements in performance on real-world PM and activities of daily living. Real-world gains were not observed in either control group. Our findings demonstrate that short-term training with the Virtual Week game produces cognitive and neural plasticity that may result in real-world benefits to supporting functional independence in older adulthood.

  20. Cognitive and neural plasticity in older adults' prospective memory following training with the Virtual Week computer game.

    Science.gov (United States)

    Rose, Nathan S; Rendell, Peter G; Hering, Alexandra; Kliegel, Matthias; Bidelman, Gavin M; Craik, Fergus I M

    2015-01-01

    Prospective memory (PM) - the ability to remember and successfully execute our intentions and planned activities - is critical for functional independence and declines with age, yet few studies have attempted to train PM in older adults. We developed a PM training program using the Virtual Week computer game. Trained participants played the game in 12, 1-h sessions over 1 month. Measures of neuropsychological functions, lab-based PM, event-related potentials (ERPs) during performance on a lab-based PM task, instrumental activities of daily living, and real-world PM were assessed before and after training. Performance was compared to both no-contact and active (music training) control groups. PM on the Virtual Week game dramatically improved following training relative to controls, suggesting PM plasticity is preserved in older adults. Relative to control participants, training did not produce reliable transfer to laboratory-based tasks, but was associated with a reduction of an ERP component (sustained negativity over occipito-parietal cortex) associated with processing PM cues, indicative of more automatic PM retrieval. Most importantly, training produced far transfer to real-world outcomes including improvements in performance on real-world PM and activities of daily living. Real-world gains were not observed in either control group. Our findings demonstrate that short-term training with the Virtual Week game produces cognitive and neural plasticity that may result in real-world benefits to supporting functional independence in older adulthood.

  1. The Mini-Cog versus the Mini-Mental State Examination and the Clock Drawing Test in daily clinical practice: screening value in a German Memory Clinic.

    Science.gov (United States)

    Milian, Monika; Leiherr, Anna-Maria; Straten, Guido; Müller, Stephan; Leyhe, Thomas; Eschweiler, Gerhard W

    2012-05-01

    The aim of this study was to compare the screening value of the Mini-Cog, Clock Drawing Test (CDT), Mini-Mental State Examination (MMSE) and the algorithm MMSE and/or CDT to separate elderly people with dementia from healthy depending on test time, type and severity of dementia, and demographic variables in a German Memory Clinic. Data from a heterogeneous patient sample and healthy participants (n = 502) were retrospectively analyzed. Of the 438 patients with dementia, 49.1% of the dementia diagnoses were Alzheimer's dementia and 50.9% were non-Alzheimer's dementia. Sixty-four participants were classified as cognitively unimpaired. The CDT and an extraction of the 3-item recall of the MMSE were used to constitute the Mini-Cog algorithm. Overall, the Mini-Cog showed significantly higher discriminatory power (86.8%) than the MMSE (72.6% at a cut-off ≤ 24 and 79.2% at ≤ 25, respectively) and CDT (78.1%) (each p 0.05). The specificity of the Mini-Cog (100.0%) was similar to that of the MMSE (100.0% for both cut-offs) and CDT (96.9%) (p = 0.154). For all age and educational groups the Mini-Cog outmatched the CDT and MMSE, and was less affected by education than MMSE and less susceptible for the dementia stage than the CDT. The Mini-Cog proved to have superior discriminatory power than either CDT or MMSE and is demonstrated to be a valid "short" screening instrument taking 3 to 4 minutes to administer in the geriatric setting.

  2. Manipulation of mental models of anatomy in interventional radiology and its consequences for design of human–computer interaction

    NARCIS (Netherlands)

    Varga, E.; Pattynama, P.M.T.; Freudenthal, A.

    2012-01-01

    Interventional radiology procedures require extensive cognitive processing from the physician. A set of these cognitive functions are aimed to be replaced by technology in order to reduce the cognitive load. However, limited knowledge is available regarding mental processes in interventional

  3. An Exceptional Memory

    Science.gov (United States)

    Hunter, Ian M. L.

    1977-01-01

    An account is given of the exceptional memory of the late Professor A. C. Aitken who was also a distinguished mathematician and mental calculator. Compared with Shereshevskii, another man with exceptional memory, he shows the scholar's reliance on conceptual mapping rather than the mnemonist's reliance on perceptual chaining. (Editor)

  4. An A.P.L. micro-programmed machine: implementation on a Multi-20 mini-computer, memory organization, micro-programming and flowcharts

    International Nuclear Information System (INIS)

    Granger, Jean-Louis

    1975-01-01

    This work deals with the presentation of an APL interpreter implemented on an MULTI 20 mini-computer. It includes a left to right syntax analyser, a recursive routine for generation and execution. This routine uses a beating method for array processing. Moreover, during the execution of all APL statements, dynamic memory allocation is used. Execution of basic operations has been micro-programmed. The basic APL interpreter has a length of 10 K bytes. It uses overlay methods. (author) [fr

  5. "Insufficient evidence of effectiveness" is not "evidence of no effectiveness:" evaluating computer-based education for patients with severe mental illness.

    Science.gov (United States)

    Stoltz, Peter; Skärsäter, Ingela; Willman, Ania

    2009-01-01

    This article reports on commissioned research funded by the Swedish Council of Technology Assessment in Health Care (SBU) and the Swedish Nursing Society (SSF). The objective was to review computer-based education programs. However, as the review produced insufficient evidence of effectiveness, the publication was withheld due to a previous incident where such evidence was misunderstood by Swedish policy and health care decision makers. This article highlights the concept of evidence with regard to the consequences of insufficient evidence of effectiveness being mistaken for evidence of no effectiveness. The aim is also to present a systematic review evaluating a computer-based education program for patients suffering from severe mental illness. Systematic database searches in Medline, CINAHL, PsycINFO and the Cochrane Library identified a total of 131 potentially relevant references. Thereafter, 27 references were retrieved as full-text documents, of which 5 were finally included and co-reviewed by two independent researchers. The review found no decisive evidence of effectiveness regarding computer-based education programs designed to assist persons suffering from severe mental illness. Failing to see the difference between insufficient evidence and evidence of no effectiveness may have unexpected consequences. As a result, practice may be misguided and treatments withheld, which at worse may have harmful consequences for patients. In the end, it is of utmost importance that researchers do good quality research by ensuring statistical power and quality of outcome measurement. For example, this review of computer-based education programs could have revealed effective ways of dealing with severe mental illness if the studies included had been conducted using more sophisticated designs.

  6. A theory-based computer mediated communication intervention to promote mental health and reduce high-risk behaviors in the LGBT population.

    Science.gov (United States)

    DiNapoli, Jean Marie; Garcia-Dia, Mary Joy; Garcia-Ona, Leila; O'Flaherty, Deirdre; Siller, Jennifer

    2014-02-01

    The Healthy People 2020 (2012) report has identified that isolation, lack of social services, and a shortage of culturally competent providers serve as barriers to the health of lesbian, gay, bisexual, and transgender (LGBT) individuals who have HIV/AIDS. Self-transcendence theory proposes that individuals who face increased vulnerability or mortality may acquire an increased capacity for self-transcendence and its positive influence on mental health and well-being. The use of technology-enabled social and community support and group interventions through computer mediated self-help (CMSH) with LGBT individuals may help meet mental health needs of this group, and support healthy lifestyle practices. This article presents an overview of steps taken to propose a theory-based CMSH intervention for testing in research and eventual application in practice. © 2013.

  7. FitzPatrick Lecture: King George III and the porphyria myth - causes, consequences and re-evaluation of his mental illness with computer diagnostics.

    Science.gov (United States)

    Peters, Timothy

    2015-04-01

    Recent studies have shown that the claim that King George III suffered from acute porphyria is seriously at fault. This article explores some of the causes of this misdiagnosis and the consequences of the misleading claims, also reporting on the nature of the king's recurrent mental illness according to computer diagnostics. In addition, techniques of cognitive archaeology are used to investigate the nature of the king's final decade of mental illness, which resulted in the appointment of the Prince of Wales as Prince Regent. The results of this analysis confirm that the king suffered from bipolar disorder type I, with a final decade of dementia, due, in part, to the neurotoxicity of his recurrent episodes of acute mania. © 2015 Royal College of Physicians.

  8. Analogous Mechanisms of Selection and Updating in Declarative and Procedural Working Memory: Experiments and a Computational Model

    Science.gov (United States)

    Oberauer, Klaus; Souza, Alessandra S.; Druey, Michel D.; Gade, Miriam

    2013-01-01

    The article investigates the mechanisms of selecting and updating representations in declarative and procedural working memory (WM). Declarative WM holds the objects of thought available, whereas procedural WM holds representations of what to do with these objects. Both systems consist of three embedded components: activated long-term memory, a…

  9. The Memory Aid study: protocol for a randomized controlled clinical trial evaluating the effect of computer-based working memory training in elderly patients with mild cognitive impairment (MCI).

    Science.gov (United States)

    Flak, Marianne M; Hernes, Susanne S; Chang, Linda; Ernst, Thomas; Douet, Vanessa; Skranes, Jon; Løhaugen, Gro C C

    2014-05-03

    Mild cognitive impairment (MCI) is a condition characterized by memory problems that are more severe than the normal cognitive changes due to aging, but less severe than dementia. Reduced working memory (WM) is regarded as one of the core symptoms of an MCI condition. Recent studies have indicated that WM can be improved through computer-based training. The objective of this study is to evaluate if WM training is effective in improving cognitive function in elderly patients with MCI, and if cognitive training induces structural changes in the white and gray matter of the brain, as assessed by structural MRI. The proposed study is a blinded, randomized, controlled trail that will include 90 elderly patients diagnosed with MCI at a hospital-based memory clinic. The participants will be randomized to either a training program or a placebo version of the program. The intervention is computerized WM training performed for 45 minutes of 25 sessions over 5 weeks. The placebo version is identical in duration but is non-adaptive in the difficulty level of the tasks. Neuropsychological assessment and structural MRI will be performed before and 1 month after training, and at a 5-month folllow-up. If computer-based training results in positive changes to memory functions in patients with MCI this may represent a new, cost-effective treatment for MCI. Secondly, evaluation of any training-induced structural changes to gray or white matter will improve the current understanding of the mechanisms behind effective cognitive interventions in patients with MCI. ClinicalTrials.gov NCT01991405. November 18, 2013.

  10. Multichannel analyzer using the direct-memory-access channel in a personal computer; Mnogokanal`nyj analizator v personal`nom komp`yutere, ispol`zuyushchij kanal pryamogo dostupa k pamyati

    Energy Technology Data Exchange (ETDEWEB)

    Georgiev, G; Vankov, I; Dimitrov, L [Incn. Yadernykh Issledovanij i Yadernoj Ehnergetiki Bolgarskoj Akademii Nuk, Sofiya (Bulgaria); Peev, I [Firma TOIVEL, Sofiya (Bulgaria)

    1996-12-31

    Paper describes a multichannel analyzer of the spectrometry data developed on the basis of a personal computer memory and a controlled channel of direct access. Analyzer software covering a driver and program of spectrum display control is studied. 2 figs.

  11. Teuchos C++ memory management classes, idioms, and related topics, the complete reference : a comprehensive strategy for safe and efficient memory management in C++ for high performance computing.

    Energy Technology Data Exchange (ETDEWEB)

    Bartlett, Roscoe Ainsworth

    2010-05-01

    The ubiquitous use of raw pointers in higher-level code is the primary cause of all memory usage problems and memory leaks in C++ programs. This paper describes what might be considered a radical approach to the problem which is to encapsulate the use of all raw pointers and all raw calls to new and delete in higher-level C++ code. Instead, a set of cooperating template classes developed in the Trilinos package Teuchos are used to encapsulate every use of raw C++ pointers in every use case where it appears in high-level code. Included in the set of memory management classes is the typical reference-counted smart pointer class similar to boost::shared ptr (and therefore C++0x std::shared ptr). However, what is missing in boost and the new standard library are non-reference counted classes for remaining use cases where raw C++ pointers would need to be used. These classes have a debug build mode where nearly all programmer errors are caught and gracefully reported at runtime. The default optimized build mode strips all runtime checks and allows the code to perform as efficiently as raw C++ pointers with reasonable usage. Also included is a novel approach for dealing with the circular references problem that imparts little extra overhead and is almost completely invisible to most of the code (unlike the boost and therefore C++0x approach). Rather than being a radical approach, encapsulating all raw C++ pointers is simply the logical progression of a trend in the C++ development and standards community that started with std::auto ptr and is continued (but not finished) with std::shared ptr in C++0x. Using the Teuchos reference-counted memory management classes allows one to remove unnecessary constraints in the use of objects by removing arbitrary lifetime ordering constraints which are a type of unnecessary coupling [23]. The code one writes with these classes will be more likely to be correct on first writing, will be less likely to contain silent (but deadly) memory

  12. Primary intervention for memory structuring and meaning acquisition (PIMSMA): study of a mental health first-aid intervention in the ED with injured survivors of suicide bombing attacks.

    Science.gov (United States)

    Schreiber, Shaul; Dolberg, Ornah T; Barkai, Gabriel; Peles, Einat; Leor, Agnes; Rapoport, Elena; Heinik, Jeremia; Bloch, Miki

    2007-01-01

    To assess the impact of a structured intervention, the "primary intervention for memory structuring and meaning acquisition" (PIMSMA) performed randomly in the emergency department with survivors of suicide bombing attacks, on their medium-term mental health outcome. Follow up and assessment 3-9 months postinjury, and 24 months thereafter. A tertiary referral general hospital in Tel Aviv, Israel. Injured survivors of 9 suicide bombing and suicide shooting, men and women aged 16-72 at the time of the incident. Diagnosis of posttraumatic stress disorder (PTSD) was made using the Hebrew validated version of the DSM-IV SCID-PTSD rating scale. Other psychiatric symptoms were assessed using the following rating scales: impact of event scale (IES), Hamilton rating scale for depression (HAM-D) and for anxiety (HAM-A), and the Pittsburgh sleep quality index (PSQI). Effects of PIMSMA and PTSD level of psychological distress were analyzed using ANOVA and for change over time for continuous variables repeated measured multivariate analyses was performed, and for categorical variables nonparametric-related sample McNemar. Logistic regression for variable associated with PTSD was performed. Out of 213 eligible injured survivors evacuated to our ER, 129 were retrieved 3-9 months after the incident, and 53 were available for assessment 2 years later. Multivariate analyses for being PTSD vs non-PTSD at the first evaluation, being hospitalized OR = 5.6 (95 percent CI 1.1-27.6) and treated OR = 24.5 (95 percent CI 2.8-200) were the only predictors, with no effect (p = 0.9) for PIMSMA vs other supportive intervention. Predictor for PTSD at the second evaluation were IES severity score at first evaluation OR = 1.1 (95 percent CI 1.04-1.2). The PIMSMA approach is as good as the nonspecific supportive treatment performed routinely in the ED with all survivors of traumatic events of any origin. Further studies are needed to establish valid, evidence-based treatment approaches for the

  13. Neural activity in the medial temporal lobe reveals the fidelity of mental time travel.

    Science.gov (United States)

    Kragel, James E; Morton, Neal W; Polyn, Sean M

    2015-02-18

    Neural circuitry in the medial temporal lobe (MTL) is critically involved in mental time travel, which involves the vivid retrieval of the details of past experience. Neuroscientific theories propose that the MTL supports memory of the past by retrieving previously encoded episodic information, as well as by reactivating a temporal code specifying the position of a particular event within an episode. However, the neural computations supporting these abilities are underspecified. To test hypotheses regarding the computational mechanisms supported by different MTL subregions during mental time travel, we developed a computational model that linked a blood oxygenation level-dependent signal to cognitive operations, allowing us to predict human performance in a memory search task. Activity in the posterior MTL, including parahippocampal cortex, reflected how strongly one reactivates the temporal context of a retrieved memory, allowing the model to predict whether the next memory will correspond to a nearby moment in the study episode. A signal in the anterior MTL, including perirhinal cortex, indicated the successful retrieval of list items, without providing information regarding temporal organization. A hippocampal signal reflected both processes, consistent with theories that this region binds item and context information together to form episodic memories. These findings provide evidence for modern theories that describe complementary roles of the hippocampus and surrounding parahippocampal and perirhinal cortices during the retrieval of episodic memories, shaping how humans revisit the past. Copyright © 2015 the authors 0270-6474/15/352914-13$15.00/0.

  14. Applications for Packetized Memory Interfaces

    OpenAIRE

    Watson, Myles Glen

    2015-01-01

    The performance of the memory subsystem has a large impact on the performance of modern computer systems. Many important applications are memory bound and others are expected to become memory bound in the future. The importance of memory performance makes it imperative to understand and optimize the interactions between applications and the system architecture. Prototyping and exploring various configurations of memory systems can give important insights, but current memory interfaces are lim...

  15. Determination of memory performance

    International Nuclear Information System (INIS)

    Gopych, P.M.

    1999-01-01

    Within the scope of testing statistical hypotheses theory a model definition and a computer method for model calculation of widely used in neuropsychology human memory performance (free recall, cued recall, and recognition probabilities), a model definition and a computer method for model calculation of intensities of cues used in experiments for testing human memory quality are proposed. Models for active and passive traces of memory and their relations are found. It was shown that autoassociative memory unit in the form of short two-layer artificial neural network with (or without) damages can be used for model description of memory performance in subjects with (or without) local brain lesions

  16. Memory-efficient analysis of dense functional connectomes

    Directory of Open Access Journals (Sweden)

    Kristian Loewe

    2016-11-01

    Full Text Available The functioning of the human brain relies on the interplay and integration of numerous individual units within a complex network. To identify network configurations characteristic of specific cognitive tasks or mental illnesses, functional connectomes can be constructed based on the assessment of synchronous fMRI activity at separate brain sites, and then analyzed using graph-theoretical concepts. In most previous studies, relatively coarse parcellations of the brain were used to define regions as graphical nodes. Such parcellated connectomes are highly dependent on parcellation quality because regional and functional boundaries need to be relatively consistent for the results to be interpretable. In contrast, dense connectomes are not subject to this limitation, since the parcellation inherent to the data is used to define graphical nodes, also allowing for a more detailed spatial mapping of connectivity patterns. However, dense connectomes are associated with considerable computational demands in terms of both time and memory requirements. The memory required to explicitly store dense connectomes in main memory can render their analysis infeasible, especially when considering high-resolution data or analyses across multiple subjects or conditions. Here, we present an object-based matrix representation that achieves a very low memory footprint by computing matrix elements on demand instead of explicitly storing them. In doing so, memory required for a dense connectome is reduced to the amount needed to store the underlying time series data. Based on theoretical considerations and benchmarks, different matrix object implementations and additional programs (based on available Matlab functions and Matlab-based third-party software are compared with regard to their computational efficiency in terms of memory requirements and computation time. The matrix implementation based on on-demand computations has very low memory requirements thus enabling

  17. Effects of Distracting Task with Different Mental Workload on Steady-State Visual Evoked Potential Based Brain Computer Interfaces—an Offline Study

    Directory of Open Access Journals (Sweden)

    Yawei Zhao

    2018-02-01

    Full Text Available Brain-computer interfaces (BCIs, independent of the brain's normal output pathways, are attracting an increasing amount of attention as devices that extract neural information. As a typical type of BCI system, the steady-state visual evoked potential (SSVEP-based BCIs possess a high signal-to-noise ratio and information transfer rate. However, the current high speed SSVEP-BCIs were implemented with subjects concentrating on stimuli, and intentionally avoided additional tasks as distractors. This paper aimed to investigate how a distracting simultaneous task, a verbal n-back task with different mental workload, would affect the performance of SSVEP-BCI. The results from fifteen subjects revealed that the recognition accuracy of SSVEP-BCI was significantly impaired by the distracting task, especially under a high mental workload. The average classification accuracy across all subjects dropped by 8.67% at most from 1- to 4-back, and there was a significant negative correlation (maximum r = −0.48, p < 0.001 between accuracy and subjective mental workload evaluation of the distracting task. This study suggests a potential hindrance for the SSVEP-BCI daily use, and then improvements should be investigated in the future studies.

  18. A passive brain-computer interface application for the mental workload assessment on professional air traffic controllers during realistic air traffic control tasks.

    Science.gov (United States)

    Aricò, P; Borghini, G; Di Flumeri, G; Colosimo, A; Pozzi, S; Babiloni, F

    2016-01-01

    In the last decades, it has been a fast-growing concept in the neuroscience field. The passive brain-computer interface (p-BCI) systems allow to improve the human-machine interaction (HMI) in operational environments, by using the covert brain activity (eg, mental workload) of the operator. However, p-BCI technology could suffer from some practical issues when used outside the laboratories. In particular, one of the most important limitations is the necessity to recalibrate the p-BCI system each time before its use, to avoid a significant reduction of its reliability in the detection of the considered mental states. The objective of the proposed study was to provide an example of p-BCIs used to evaluate the users' mental workload in a real operational environment. For this purpose, through the facilities provided by the École Nationale de l'Aviation Civile of Toulouse (France), the cerebral activity of 12 professional air traffic control officers (ATCOs) has been recorded while performing high realistic air traffic management scenarios. By the analysis of the ATCOs' brain activity (electroencephalographic signal-EEG) and the subjective workload perception (instantaneous self-assessment) provided by both the examined ATCOs and external air traffic control experts, it has been possible to estimate and evaluate the variation of the mental workload under which the controllers were operating. The results showed (i) a high significant correlation between the neurophysiological and the subjective workload assessment, and (ii) a high reliability over time (up to a month) of the proposed algorithm that was also able to maintain high discrimination accuracies by using a low number of EEG electrodes (~3 EEG channels). In conclusion, the proposed methodology demonstrated the suitability of p-BCI systems in operational environments and the advantages of the neurophysiological measures with respect to the subjective ones. © 2016 Elsevier B.V. All rights reserved.

  19. [Discriminatory validity and association of the mini-mental test (MMSE) and the memory alteration test (M@T) with a neuropsychological battery in patients with amnestic mild cognitive impairment and Alzheimer's disease].

    Science.gov (United States)

    Rami, L; Bosch, B; Valls-Pedret, C; Caprile, C; Sánchez-Valle Díaz, R; Molinuevo, J L

    To establish the discriminatory validity of the mini-mental test (MMSE) and the memory alteration test (M@T) for the diagnosis of amnestic mild cognitive impairment (aMCI) and probable Alzheimer's disease (AD), and also to study the association between the results obtained in screening tests, a neuropsychological battery and a functional questionnaire in healthy persons and in patients with aMCI and AD. We evaluated 27 normal controls, 27 patients with aMCI and 35 patients with AD using the MMSE and a memory screening test, the M@T, a neuropsychological battery and a questionnaire on functional activities of daily living. Pearson correlation coefficients were used to evaluate the relations between the scores on the M@T and the MMSE and the neuropsychological tests. The area below the curve, the sensitivity and the specificity were calculated for the screening tests. In patients with aMCI, the scores on the M@T and the MMSE were strongly associated with the performance in the episodic memory tests in frontal tests and with the scores on the functional questionnaire, but not with tests that evaluated praxias and perceptive functions. In patients with AD, the scores on the M@T and the MMSE were associated with results in semantic memory, language, executive functions and praxias, but not with perceptive tests and functional questionnaires. In patients with aMCI and AD, the association between MMSE and M@T only correlate with some cognitive functions, without there being any association with other cognitive functions. Therefore, screening tests cannot be used as the only instrument for evaluating the cognitive status in patients with suspected dementia.

  20. Brain MRI and single photon emission computed tomography in severe athetotic cerebral palsy. A comparative study with mental and motor disorders

    International Nuclear Information System (INIS)

    Yamada, Kazutaka; Tsuzura, Shigenobu; Matsuda, Hiroshi.

    1995-01-01

    Single photon emission computed tomography (SPECT) using N-isopropyl-p-[ 123 I]-iodoamphetamine ( 123 I-IMP) was performed in twelve patients with severe athetotic cerebral palsy (Ath; 5 males and 7 females) who had both motor delay (unable to move) and mental retardation (I.Q, or D.Q, below 30). The neuroimaging findings of those patients were compared with those of patients mental and motor disorders. In five caes suffering from neonatal asphyxia, SPECT demonstrated a decreased regional cerebral blood flow (rCBF) in corpus striatum, thalamus, orbitofrontal areas, pericentral gyrus areas, prefrontal areas and medial temporal areas. In seven cases suffering from neonatal jaundice, SPECT demonstrated a decreased rCBF in orbito-frontal areas, prefrontal areas and medial temporal areas. SPECT showed hypoperfusion of peri-central gyrus areas in cases with complications of spastic palsy. The decreased rCBF in medial temporal areas mostly corresponded to an alteration in hippocampal formation as assessed by magnetic resonance imaging (MRI). Cases with hypoperfusion of bilateral medial temporal areas showed a lower score of language understanding than those with the unilateral damage. In cases with hypofusion of bilateral prefrontal areas and bilateral medial temporal areas, the grade of understanding of language was almost below 12 months. In cases with hypoperfusion of orbitofrontal areas, psychomotor hypersensitivity had been observed. Those results suggest that IMP-SPECT and MRI of the brain is useful tool for neurological assessment in handicapped patients with athetotic cerebral palsy. (author)

  1. Brain MRI and single photon emission computed tomography in severe athetotic cerebral palsy. A comparative study with mental and motor disorders

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Kazutaka; Tsuzura, Shigenobu [Metropolitan Medical Center of the Severely Handicapped, Fuchu, Tokyo (Japan); Matsuda, Hiroshi

    1995-07-01

    Single photon emission computed tomography (SPECT) using N-isopropyl-p-[{sup 123}I]-iodoamphetamine ({sup 123}I-IMP) was performed in twelve patients with severe athetotic cerebral palsy (Ath; 5 males and 7 females) who had both motor delay (unable to move) and mental retardation (I.Q, or D.Q, below 30). The neuroimaging findings of those patients were compared with those of patients mental and motor disorders. In five caes suffering from neonatal asphyxia, SPECT demonstrated a decreased regional cerebral blood flow (rCBF) in corpus striatum, thalamus, orbitofrontal areas, pericentral gyrus areas, prefrontal areas and medial temporal areas. In seven cases suffering from neonatal jaundice, SPECT demonstrated a decreased rCBF in orbito-frontal areas, prefrontal areas and medial temporal areas. SPECT showed hypoperfusion of peri-central gyrus areas in cases with complications of spastic palsy. The decreased rCBF in medial temporal areas mostly corresponded to an alteration in hippocampal formation as assessed by magnetic resonance imaging (MRI). Cases with hypoperfusion of bilateral medial temporal areas showed a lower score of language understanding than those with the unilateral damage. In cases with hypofusion of bilateral prefrontal areas and bilateral medial temporal areas, the grade of understanding of language was almost below 12 months. In cases with hypoperfusion of orbitofrontal areas, psychomotor hypersensitivity had been observed. Those results suggest that IMP-SPECT and MRI of the brain is useful tool for neurological assessment in handicapped patients with athetotic cerebral palsy. (author).

  2. COMPUTING

    CERN Multimedia

    M. Kasemann

    Overview In autumn the main focus was to process and handle CRAFT data and to perform the Summer08 MC production. The operational aspects were well covered by regular Computing Shifts, experts on duty and Computing Run Coordination. At the Computing Resource Board (CRB) in October a model to account for service work at Tier 2s was approved. The computing resources for 2009 were reviewed for presentation at the C-RRB. The quarterly resource monitoring is continuing. Facilities/Infrastructure operations Operations during CRAFT data taking ran fine. This proved to be a very valuable experience for T0 workflows and operations. The transfers of custodial data to most T1s went smoothly. A first round of reprocessing started at the Tier-1 centers end of November; it will take about two weeks. The Computing Shifts procedure was tested full scale during this period and proved to be very efficient: 30 Computing Shifts Persons (CSP) and 10 Computing Resources Coordinators (CRC). The shift program for the shut down w...

  3. Music and memory

    OpenAIRE

    Haefliger, Anna Berenika

    2013-01-01

    Abstract: Music and its different forms of use seem to benefit people in a number of ways. Research has suggested that extensive musical practice and musical listening enhances mental functioning in healthy adults and patients with neurodegenerative disease. Yet, the findings presented have not yet examined the effects both musical training and stimuli enhancement have on episodic memory recognition. 20 musicians and 20 non-musicians took part in an episodic memory task which evaluated m...

  4. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction CMS distributed computing system performed well during the 2011 start-up. The events in 2011 have more pile-up and are more complex than last year; this results in longer reconstruction times and harder events to simulate. Significant increases in computing capacity were delivered in April for all computing tiers, and the utilisation and load is close to the planning predictions. All computing centre tiers performed their expected functionalities. Heavy-Ion Programme The CMS Heavy-Ion Programme had a very strong showing at the Quark Matter conference. A large number of analyses were shown. The dedicated heavy-ion reconstruction facility at the Vanderbilt Tier-2 is still involved in some commissioning activities, but is available for processing and analysis. Facilities and Infrastructure Operations Facility and Infrastructure operations have been active with operations and several important deployment tasks. Facilities participated in the testing and deployment of WMAgent and WorkQueue+Request...

  5. COMPUTING

    CERN Multimedia

    P. McBride

    The Computing Project is preparing for a busy year where the primary emphasis of the project moves towards steady operations. Following the very successful completion of Computing Software and Analysis challenge, CSA06, last fall, we have reorganized and established four groups in computing area: Commissioning, User Support, Facility/Infrastructure Operations and Data Operations. These groups work closely together with groups from the Offline Project in planning for data processing and operations. Monte Carlo production has continued since CSA06, with about 30M events produced each month to be used for HLT studies and physics validation. Monte Carlo production will continue throughout the year in the preparation of large samples for physics and detector studies ramping to 50 M events/month for CSA07. Commissioning of the full CMS computing system is a major goal for 2007. Site monitoring is an important commissioning component and work is ongoing to devise CMS specific tests to be included in Service Availa...

  6. COMPUTING

    CERN Multimedia

    M. Kasemann

    Overview During the past three months activities were focused on data operations, testing and re-enforcing shift and operational procedures for data production and transfer, MC production and on user support. Planning of the computing resources in view of the new LHC calendar in ongoing. Two new task forces were created for supporting the integration work: Site Commissioning, which develops tools helping distributed sites to monitor job and data workflows, and Analysis Support, collecting the user experience and feedback during analysis activities and developing tools to increase efficiency. The development plan for DMWM for 2009/2011 was developed at the beginning of the year, based on the requirements from the Physics, Computing and Offline groups (see Offline section). The Computing management meeting at FermiLab on February 19th and 20th was an excellent opportunity discussing the impact and for addressing issues and solutions to the main challenges facing CMS computing. The lack of manpower is particul...

  7. Empirical evidence for musical syntax processing? Computer simulations reveal the contribution of auditory short-term memory

    Directory of Open Access Journals (Sweden)

    Emmanuel eBigand

    2014-06-01

    Full Text Available During the last decade, it has been argued that 1 music processing involves syntactic representations similar to those observed in language, and 2 that music and language share similar syntactic-like processes and neural resources. This claim is important for understanding the origin of music and language abilities and, furthermore, it has clinical implications. The Western musical system, however, is rooted in psychoacoustic properties of sound, and this is not the case for linguistic syntax. Accordingly, musical syntax processing could be parsimoniously understood as an emergent property of auditory memory rather than a property of abstract processing similar to linguistic processing. To support this view, we simulated numerous empirical studies that investigated the processing of harmonic structures, using a model based on the accumulation of sensory information in auditory memory. The simulations revealed that most of the musical syntax manipulations used with behavioral and neurophysiological methods as well as with developmental and cross-cultural approaches can be accounted for by the auditory memory model. This led us to question whether current research on musical syntax can really be compared with linguistic processing. Our simulation also raises methodological and theoretical challenges to study musical syntax while disentangling the confounded low-level sensory influences. In order to investigate syntactic abilities in music comparable to language, research should preferentially use musical material with structures that circumvent the tonal effect exerted by psychoacoustic properties of sounds.

  8. Empirical evidence for musical syntax processing? Computer simulations reveal the contribution of auditory short-term memory.

    Science.gov (United States)

    Bigand, Emmanuel; Delbé, Charles; Poulin-Charronnat, Bénédicte; Leman, Marc; Tillmann, Barbara

    2014-01-01

    During the last decade, it has been argued that (1) music processing involves syntactic representations similar to those observed in language, and (2) that music and language share similar syntactic-like processes and neural resources. This claim is important for understanding the origin of music and language abilities and, furthermore, it has clinical implications. The Western musical system, however, is rooted in psychoacoustic properties of sound, and this is not the case for linguistic syntax. Accordingly, musical syntax processing could be parsimoniously understood as an emergent property of auditory memory rather than a property of abstract processing similar to linguistic processing. To support this view, we simulated numerous empirical studies that investigated the processing of harmonic structures, using a model based on the accumulation of sensory information in auditory memory. The simulations revealed that most of the musical syntax manipulations used with behavioral and neurophysiological methods as well as with developmental and cross-cultural approaches can be accounted for by the auditory memory model. This led us to question whether current research on musical syntax can really be compared with linguistic processing. Our simulation also raises methodological and theoretical challenges to study musical syntax while disentangling the confounded low-level sensory influences. In order to investigate syntactic abilities in music comparable to language, research should preferentially use musical material with structures that circumvent the tonal effect exerted by psychoacoustic properties of sounds.

  9. Empirical evidence for musical syntax processing? Computer simulations reveal the contribution of auditory short-term memory

    Science.gov (United States)

    Bigand, Emmanuel; Delbé, Charles; Poulin-Charronnat, Bénédicte; Leman, Marc; Tillmann, Barbara

    2014-01-01

    During the last decade, it has been argued that (1) music processing involves syntactic representations similar to those observed in language, and (2) that music and language share similar syntactic-like processes and neural resources. This claim is important for understanding the origin of music and language abilities and, furthermore, it has clinical implications. The Western musical system, however, is rooted in psychoacoustic properties of sound, and this is not the case for linguistic syntax. Accordingly, musical syntax processing could be parsimoniously understood as an emergent property of auditory memory rather than a property of abstract processing similar to linguistic processing. To support this view, we simulated numerous empirical studies that investigated the processing of harmonic structures, using a model based on the accumulation of sensory information in auditory memory. The simulations revealed that most of the musical syntax manipulations used with behavioral and neurophysiological methods as well as with developmental and cross-cultural approaches can be accounted for by the auditory memory model. This led us to question whether current research on musical syntax can really be compared with linguistic processing. Our simulation also raises methodological and theoretical challenges to study musical syntax while disentangling the confounded low-level sensory influences. In order to investigate syntactic abilities in music comparable to language, research should preferentially use musical material with structures that circumvent the tonal effect exerted by psychoacoustic properties of sounds. PMID:24936174

  10. Memory-Efficient Analysis of Dense Functional Connectomes.

    Science.gov (United States)

    Loewe, Kristian; Donohue, Sarah E; Schoenfeld, Mircea A; Kruse, Rudolf; Borgelt, Christian

    2016-01-01

    The functioning of the human brain relies on the interplay and integration of numerous individual units within a complex network. To identify network configurations characteristic of specific cognitive tasks or mental illnesses, functional connectomes can be constructed based on the assessment of synchronous fMRI activity at separate brain sites, and then analyzed using graph-theoretical concepts. In most previous studies, relatively coarse parcellations of the brain were used to define regions as graphical nodes. Such parcellated connectomes are highly dependent on parcellation quality because regional and functional boundaries need to be relatively consistent for the results to be interpretable. In contrast, dense connectomes are not subject to this limitation, since the parcellation inherent to the data is used to define graphical nodes, also allowing for a more detailed spatial mapping of connectivity patterns. However, dense connectomes are associated with considerable computational demands in terms of both time and memory requirements. The memory required to explicitly store dense connectomes in main memory can render their analysis infeasible, especially when considering high-resolution data or analyses across multiple subjects or conditions. Here, we present an object-based matrix representation that achieves a very low memory footprint by computing matrix elements on demand instead of explicitly storing them. In doing so, memory required for a dense connectome is reduced to the amount needed to store the underlying time series data. Based on theoretical considerations and benchmarks, different matrix object implementations and additional programs (based on available Matlab functions and Matlab-based third-party software) are compared with regard to their computational efficiency. The matrix implementation based on on-demand computations has very low memory requirements, thus enabling analyses that would be otherwise infeasible to conduct due to

  11. Neutron detection and characterization for non-proliferation applications using 3D computer optical memories [Use of 3D optical computer memory for radiation detectors/dosimeters. Final progress report

    International Nuclear Information System (INIS)

    Phillips, Gary W.

    2000-01-01

    We have investigated 3-dimensional optical random access memory (3D-ORAM) materials for detection and characterization of charged particles of neutrons by detecting tracks left by the recoil charged particles produced by the neutrons. We have characterized the response of these materials to protons, alpha particles and carbon-12 nuclei as a functions of dose and energy. We have observed individual tracks using scanning electron microscopy and atomic force microscopy. We are investigating the use of neural net analysis to characterize energetic neutron fields from their track structure in these materials

  12. Quantum memory Quantum memory

    Science.gov (United States)

    Le Gouët, Jean-Louis; Moiseev, Sergey

    2012-06-01

    Interaction of quantum radiation with multi-particle ensembles has sparked off intense research efforts during the past decade. Emblematic of this field is the quantum memory scheme, where a quantum state of light is mapped onto an ensemble of atoms and then recovered in its original shape. While opening new access to the basics of light-atom interaction, quantum memory also appears as a key element for information processing applications, such as linear optics quantum computation and long-distance quantum communication via quantum repeaters. Not surprisingly, it is far from trivial to practically recover a stored quantum state of light and, although impressive progress has already been accomplished, researchers are still struggling to reach this ambitious objective. This special issue provides an account of the state-of-the-art in a fast-moving research area that makes physicists, engineers and chemists work together at the forefront of their discipline, involving quantum fields and atoms in different media, magnetic resonance techniques and material science. Various strategies have been considered to store and retrieve quantum light. The explored designs belong to three main—while still overlapping—classes. In architectures derived from photon echo, information is mapped over the spectral components of inhomogeneously broadened absorption bands, such as those encountered in rare earth ion doped crystals and atomic gases in external gradient magnetic field. Protocols based on electromagnetic induced transparency also rely on resonant excitation and are ideally suited to the homogeneous absorption lines offered by laser cooled atomic clouds or ion Coulomb crystals. Finally off-resonance approaches are illustrated by Faraday and Raman processes. Coupling with an optical cavity may enhance the storage process, even for negligibly small atom number. Multiple scattering is also proposed as a way to enlarge the quantum interaction distance of light with matter. The

  13. COMPUTING

    CERN Multimedia

    I. Fisk

    2013-01-01

    Computing activity had ramped down after the completion of the reprocessing of the 2012 data and parked data, but is increasing with new simulation samples for analysis and upgrade studies. Much of the Computing effort is currently involved in activities to improve the computing system in preparation for 2015. Operations Office Since the beginning of 2013, the Computing Operations team successfully re-processed the 2012 data in record time, not only by using opportunistic resources like the San Diego Supercomputer Center which was accessible, to re-process the primary datasets HTMHT and MultiJet in Run2012D much earlier than planned. The Heavy-Ion data-taking period was successfully concluded in February collecting almost 500 T. Figure 3: Number of events per month (data) In LS1, our emphasis is to increase efficiency and flexibility of the infrastructure and operation. Computing Operations is working on separating disk and tape at the Tier-1 sites and the full implementation of the xrootd federation ...

  14. The Relevance of the Functional 5-HT1A Receptor Polymorphism for Attention and Working Memory Processes during Mental Rotation of Characters

    Science.gov (United States)

    Beste, Christian; Heil, Martin; Domschke, Katharina; Konrad, Carsten

    2010-01-01

    Numerous lines of research indicate that attentional processes, working memory and saccadic processes are highly interrelated. In the current study, we examine the relation between these processes with respect to their cognitive-neurophysiological and neurobiological background by means of event-related potentials (ERPs) in a sample of N = 72…

  15. Mental rotation impairs attention shifting and short-term memory encoding: neurophysiological evidence against the response-selection bottleneck model of dual-task performance

    NARCIS (Netherlands)

    Pannebakker, M.M.; van Dam, W.O.; Band, G.P.H.; Ridderinkhof, K.R.; Hommel, B.

    2011-01-01

    Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial

  16. COMPUTING

    CERN Multimedia

    I. Fisk

    2010-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion An activity that is still in progress is computing for the heavy-ion program. The heavy-ion events are collected without zero suppression, so the event size is much large at roughly 11 MB per event of RAW. The central collisions are more complex and...

  17. COMPUTING

    CERN Multimedia

    M. Kasemann P. McBride Edited by M-C. Sawley with contributions from: P. Kreuzer D. Bonacorsi S. Belforte F. Wuerthwein L. Bauerdick K. Lassila-Perini M-C. Sawley

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the comput...

  18. Detection of memory impairment among community-dwelling elderly by using the Rivermead Behavioural Memory Test

    International Nuclear Information System (INIS)

    Shinagawa, Shunichiro; Toyota, Yasutaka; Matsumoto, Teruhisa; Sonobe, Naomi; Adachi, Hiroyoshi; Mori, Takaaki; Ishikawa, Tomohisa; Fukuhara, Ryuji; Ikeda, Manabu

    2010-01-01

    The aim of this study was to use the Rivermead Behavioural Memory Test (RBMT) to evaluate everyday memory impairment among community-dwelling elderly who had normal cognitive function and performed daily activities normally but displayed memory impairments, and to diagnose the condition as either mild cognitive impairment or dementia. Among the 1,290 community-dwelling elderly persons who participated in the study, 72 subjects scored higher than 24 on the Mini-Mental State Examination (MMSE): these subjects performed daily activities normally, but their family members reported that they showed memory impairments. Fifty-two subjects completed RBMT, Clinical Dementia Rating, and brain computed tomography, and a final diagnosis was established. The mean standard profile score was 15.1±5.0 and mean screening score was 6.4±3.0. RBMT score was correlated with the MMSE score. Nine of the subjects were diagnosed with dementia and 26 of them were found to be normal. RBMT achieved 100% sensitivity and specificity with regard to the differentiation of subjects with Alzheimer's disease. However, some subjects were diagnosed with dementia even though their RBMT score was higher than the cut-off score. RBMT was useful in detecting memory impairments of Alzheimer's disease (AD) subjects in community-based surveys. However, some subjects were diagnosed with dementia because of the existence of other cognitive impairments among community-dwelling elderly. (author)

  19. Computer-Based Cognitive Programs for Improvement of Memory, Processing Speed and Executive Function during Age-Related Cognitive Decline: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Yan-kun Shao

    Full Text Available Several studies have assessed the effects of computer-based cognitive programs (CCP in the management of age-related cognitive decline, but the role of CCP remains controversial. Therefore, this systematic review evaluated the evidence on the efficacy of CCP for age-related cognitive decline in healthy older adults.Six electronic databases (through October 2014 were searched. The risk of bias was assessed using the Cochrane Collaboration tool. The standardized mean difference (SMD and 95% confidence intervals (CI of a random-effects model were calculated. The heterogeneity was assessed using the Cochran Q statistic and quantified with the I2 index.Twelve studies were included in the current review and were considered as moderate to high methodological quality. The aggregated results indicate that CCP improves memory performance (SMD, 0.31; 95% CI 0.16 to 0.45; p < 0.0001 and processing speed (SMD, 0.50; 95% CI 0.14 to 0.87; p = 0.007 but not executive function (SMD, -0.12; 95% CI -0.33 to 0.09; p = 0.27. Furthermore, there were long-term gains in memory performance (SMD, 0.59; 95% CI 0.13 to 1.05; p = 0.01.CCP may be a valid complementary and alternative therapy for age-related cognitive decline, especially for memory performance and processing speed. However, more studies with longer follow-ups are warranted to confirm the current findings.

  20. Predictive Place-Cell Sequences for Goal-Finding Emerge from Goal Memory and the Cognitive Map: A Computational Model

    Directory of Open Access Journals (Sweden)

    Lorenz Gönner

    2017-10-01

    Full Text Available Hippocampal place-cell sequences observed during awake immobility often represent previous experience, suggesting a role in memory processes. However, recent reports of goals being overrepresented in sequential activity suggest a role in short-term planning, although a detailed understanding of the origins of hippocampal sequential activity and of its functional role is still lacking. In particular, it is unknown which mechanism could support efficient planning by generating place-cell sequences biased toward known goal locations, in an adaptive and constructive fashion. To address these questions, we propose a model of spatial learning and sequence generation as interdependent processes, integrating cortical contextual coding, synaptic plasticity and neuromodulatory mechanisms into a map-based approach. Following goal learning, sequential activity emerges from continuous attractor network dynamics biased by goal memory inputs. We apply Bayesian decoding on the resulting spike trains, allowing a direct comparison with experimental data. Simulations show that this model (1 explains the generation of never-experienced sequence trajectories in familiar environments, without requiring virtual self-motion signals, (2 accounts for the bias in place-cell sequences toward goal locations, (3 highlights their utility in flexible route planning, and (4 provides specific testable predictions.

  1. Adaptive Automation Triggered by EEG-Based Mental Workload Index: A Passive Brain-Computer Interface Application in Realistic Air Traffic Control Environment.

    Science.gov (United States)

    Aricò, Pietro; Borghini, Gianluca; Di Flumeri, Gianluca; Colosimo, Alfredo; Bonelli, Stefano; Golfetti, Alessia; Pozzi, Simone; Imbert, Jean-Paul; Granger, Géraud; Benhacene, Raïlane; Babiloni, Fabio

    2016-01-01

    Adaptive Automation (AA) is a promising approach to keep the task workload demand within appropriate levels in order to avoid both the under - and over-load conditions, hence enhancing the overall performance and safety of the human-machine system. The main issue on the use of AA is how to trigger the AA solutions without affecting the operative task. In this regard, passive Brain-Computer Interface (pBCI) systems are a good candidate to activate automation, since they are able to gather information about the covert behavior (e.g., mental workload) of a subject by analyzing its neurophysiological signals (i.e., brain activity), and without interfering with the ongoing operational activity. We proposed a pBCI system able to trigger AA solutions integrated in a realistic Air Traffic Management (ATM) research simulator developed and hosted at ENAC (É cole Nationale de l'Aviation Civile of Toulouse, France). Twelve Air Traffic Controller (ATCO) students have been involved in the experiment and they have been asked to perform ATM scenarios with and without the support of the AA solutions. Results demonstrated the effectiveness of the proposed pBCI system, since it enabled the AA mostly during the high-demanding conditions (i.e., overload situations) inducing a reduction of the mental workload under which the ATCOs were operating. On the contrary, as desired, the AA was not activated when workload level was under the threshold, to prevent too low demanding conditions that could bring the operator's workload level toward potentially dangerous conditions of underload.

  2. Personal Computers.

    Science.gov (United States)

    Toong, Hoo-min D.; Gupta, Amar

    1982-01-01

    Describes the hardware, software, applications, and current proliferation of personal computers (microcomputers). Includes discussions of microprocessors, memory, output (including printers), application programs, the microcomputer industry, and major microcomputer manufacturers (Apple, Radio Shack, Commodore, and IBM). (JN)

  3. COMPUTING

    CERN Multimedia

    P. McBride

    It has been a very active year for the computing project with strong contributions from members of the global community. The project has focused on site preparation and Monte Carlo production. The operations group has begun processing data from P5 as part of the global data commissioning. Improvements in transfer rates and site availability have been seen as computing sites across the globe prepare for large scale production and analysis as part of CSA07. Preparations for the upcoming Computing Software and Analysis Challenge CSA07 are progressing. Ian Fisk and Neil Geddes have been appointed as coordinators for the challenge. CSA07 will include production tests of the Tier-0 production system, reprocessing at the Tier-1 sites and Monte Carlo production at the Tier-2 sites. At the same time there will be a large analysis exercise at the Tier-2 centres. Pre-production simulation of the Monte Carlo events for the challenge is beginning. Scale tests of the Tier-0 will begin in mid-July and the challenge it...

  4. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction During the past six months, Computing participated in the STEP09 exercise, had a major involvement in the October exercise and has been working with CMS sites on improving open issues relevant for data taking. At the same time operations for MC production, real data reconstruction and re-reconstructions and data transfers at large scales were performed. STEP09 was successfully conducted in June as a joint exercise with ATLAS and the other experiments. It gave good indication about the readiness of the WLCG infrastructure with the two major LHC experiments stressing the reading, writing and processing of physics data. The October Exercise, in contrast, was conducted as an all-CMS exercise, where Physics, Computing and Offline worked on a common plan to exercise all steps to efficiently access and analyze data. As one of the major results, the CMS Tier-2s demonstrated to be fully capable for performing data analysis. In recent weeks, efforts were devoted to CMS Computing readiness. All th...

  5. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion The Tier 0 infrastructure was able to repack and promptly reconstruct heavy-ion collision data. Two copies were made of the data at CERN using a large CASTOR disk pool, and the core physics sample was replicated ...

  6. COMPUTING

    CERN Multimedia

    I. Fisk

    2012-01-01

    Introduction Computing continued with a high level of activity over the winter in preparation for conferences and the start of the 2012 run. 2012 brings new challenges with a new energy, more complex events, and the need to make the best use of the available time before the Long Shutdown. We expect to be resource constrained on all tiers of the computing system in 2012 and are working to ensure the high-priority goals of CMS are not impacted. Heavy ions After a successful 2011 heavy-ion run, the programme is moving to analysis. During the run, the CAF resources were well used for prompt analysis. Since then in 2012 on average 200 job slots have been used continuously at Vanderbilt for analysis workflows. Operations Office As of 2012, the Computing Project emphasis has moved from commissioning to operation of the various systems. This is reflected in the new organisation structure where the Facilities and Data Operations tasks have been merged into a common Operations Office, which now covers everything ...

  7. COMPUTING

    CERN Multimedia

    M. Kasemann

    CCRC’08 challenges and CSA08 During the February campaign of the Common Computing readiness challenges (CCRC’08), the CMS computing team had achieved very good results. The link between the detector site and the Tier0 was tested by gradually increasing the number of parallel transfer streams well beyond the target. Tests covered the global robustness at the Tier0, processing a massive number of very large files and with a high writing speed to tapes.  Other tests covered the links between the different Tiers of the distributed infrastructure and the pre-staging and reprocessing capacity of the Tier1’s: response time, data transfer rate and success rate for Tape to Buffer staging of files kept exclusively on Tape were measured. In all cases, coordination with the sites was efficient and no serious problem was found. These successful preparations prepared the ground for the second phase of the CCRC’08 campaign, in May. The Computing Software and Analysis challen...

  8. COMPUTING

    CERN Multimedia

    I. Fisk

    2010-01-01

    Introduction The first data taking period of November produced a first scientific paper, and this is a very satisfactory step for Computing. It also gave the invaluable opportunity to learn and debrief from this first, intense period, and make the necessary adaptations. The alarm procedures between different groups (DAQ, Physics, T0 processing, Alignment/calibration, T1 and T2 communications) have been reinforced. A major effort has also been invested into remodeling and optimizing operator tasks in all activities in Computing, in parallel with the recruitment of new Cat A operators. The teams are being completed and by mid year the new tasks will have been assigned. CRB (Computing Resource Board) The Board met twice since last CMS week. In December it reviewed the experience of the November data-taking period and could measure the positive improvements made for the site readiness. It also reviewed the policy under which Tier-2 are associated with Physics Groups. Such associations are decided twice per ye...

  9. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the co...

  10. Cognitive status, lexical learning and memory in deaf adults using sign language

    Directory of Open Access Journals (Sweden)

    Zahra Jafari

    2013-05-01

    Full Text Available Background and Aim : Learning and memory are two high level cognitive performances in human that hearing loss influences them. In our study, mini-mental state examination (MMSE and Ray auditory-verbal learning test (RAVLT was conducted to study cognitive stat us and lexical learning and memory in deaf adults using sign language. Methods: This cross-sectional comparative study was conducted on 30 available congenitally deaf adults using sign language in Persian and 46 normal adults aged 19 to 27 years for both sexes, with a minimum of diploma level of education. After mini-mental state examination, Rey auditory-verbal learning test was run through computers to evaluate lexical learning and memory with visual presentation. Results: Mean scores of mini-mental state examination and Rey auditory-verbal learning test in congenitally deaf adults were significantly lower than normal individuals in all scores (p=0.018 except in the two parts of the Rey test. Significant correlation was found between results of two tests just in the normal group (p=0.043. Gender had no effect on test results. Conclusion: Cognitive status and lexical memory and learning in congenitally deaf individuals is weaker than in normal subjects. It seems that using sign language as the main way of communication in deaf people causes poor lexical memory and learning.

  11. Computer Games as a Tool for Implementation of Memory Policy (on the Example of Displaying Events of The Great Patriotic War in Video Games

    Directory of Open Access Journals (Sweden)

    Сергей Игоревич Белов

    2018-12-01

    Full Text Available The presented work is devoted to the study of the practice of using computer games as a tool of the memory policy. The relevance of this study determines both the growth of the importance of video games as a means of forming ideas about the events of the past, and a low degree of study of this topic. As the goal of the author's research, the research is to identify the prospects for using computer games as an instrument for implementing the memory policy within the framework of the case of the events of the Great Patriotic War. The empirical base of the work was formed due to the generalization of the content of such video games as “Call of Duty 1”, “Call of Duty 14: WWII”, “Company of Heroes 2” and “Commandos 3: Destination Berlin”. The methodological base of the research is formed due to the involvement of elements of descriptive political analysis, the theory of operant conditioning B.F. Skinner and the concept of social identity H. Tajfel and J. Turner. The author comes to the conclusion that familiarization of users with the designated games contributes to the consolidation in the minds of users of negative stereotypes regarding the participation of the Red Army in the Great Patriotic War. The process of integration of negative images is carried out using the methods of operant conditioning. The integration of the system of negative images into the mass consciousness of the inhabitants of the post-Soviet space makes it difficult to preserve the remnants of Soviet political symbols and elements constructed on their basis identity. The author puts forward the hypothesis that in the case of complete desovietization of the public policy space in the states that emerged as a result of the collapse of the USSR, the task of revising the history of the Great Patriotic War will be greatly facilitated, and with the subsequent departure from the life of the last eyewitnesses of the relevant events, achieving this goal will be only a

  12. Emotion and Autobiographical Memory

    Directory of Open Access Journals (Sweden)

    Nuray Sarp

    2011-09-01

    Full Text Available Self and mind are constituted with the cumulative effects of significant life events. This description is regarded as a given explicitly or implicitly in vari-ous theories of personality. Such an acknowledgment inevitably brings together these theories on two basic concepts. The first one is the emotions that give meaning to experiences and the second one is the memory which is related to the storage of these experiences. The part of the memory which is responsible for the storage and retrieval of life events is the autobiographical memory. Besides the development of personality, emotions and autobiographical memory are important in the development of and maintenance of psychopathology. Therefore, these two concepts have both longitudinal and cross-sectional functions in understanding human beings. In case of psychopathology, understanding emotions and autobiographical memory developmentally, aids in understanding the internal susceptibility factors. In addition, understanding how these two structures work and influence each other in an acute event would help to understand the etiological mechanisms of mental disorders. In the literature, theories that include both of these structures and that have clinical implications, are inconclusive. Theories on memory generally focus on cognitive and semantic structures while neglecting emotions, whereas theories on emotions generally neglect memory and its organization. There are only a few theories that cover both of these two concepts. In the present article, these theories that include both emotions and autobiographical memory in the same framework (i.e. Self Memory System, Associative Network Theory, Structural and Contextual theories and Affect Regulation Theory were discussed to see the full picture. Taken together, these theories seem to have the potential to suggest data-driven models in understanding and explaining symptoms such as flashbacks, dissociation, amnesia, over general memory seen in

  13. Evaluation of Short Term Memory Span Function In Children

    OpenAIRE

    Barış ERGÜL; Arzu ALTIN YAVUZ; Ebru GÜNDOĞAN AŞIK

    2016-01-01

    Although details of the information encoded in the short-term memory where it is stored temporarily be recorded in the working memory in the next stage. Repeating the information mentally makes it remain in memory for a long time. Studies investigating the relationship between short-term memory and reading skills that are carried out to examine the relationship between short-term memory processes and reading comprehension. In this study information coming to short-term memory and the factors ...

  14. Memory architecture

    NARCIS (Netherlands)

    2012-01-01

    A memory architecture is presented. The memory architecture comprises a first memory and a second memory. The first memory has at least a bank with a first width addressable by a single address. The second memory has a plurality of banks of a second width, said banks being addressable by components

  15. COMPUTING

    CERN Multimedia

    2010-01-01

    Introduction Just two months after the “LHC First Physics” event of 30th March, the analysis of the O(200) million 7 TeV collision events in CMS accumulated during the first 60 days is well under way. The consistency of the CMS computing model has been confirmed during these first weeks of data taking. This model is based on a hierarchy of use-cases deployed between the different tiers and, in particular, the distribution of RECO data to T1s, who then serve data on request to T2s, along a topology known as “fat tree”. Indeed, during this period this model was further extended by almost full “mesh” commissioning, meaning that RECO data were shipped to T2s whenever possible, enabling additional physics analyses compared with the “fat tree” model. Computing activities at the CMS Analysis Facility (CAF) have been marked by a good time response for a load almost evenly shared between ALCA (Alignment and Calibration tasks - highest p...

  16. COMPUTING

    CERN Multimedia

    Contributions from I. Fisk

    2012-01-01

    Introduction The start of the 2012 run has been busy for Computing. We have reconstructed, archived, and served a larger sample of new data than in 2011, and we are in the process of producing an even larger new sample of simulations at 8 TeV. The running conditions and system performance are largely what was anticipated in the plan, thanks to the hard work and preparation of many people. Heavy ions Heavy Ions has been actively analysing data and preparing for conferences.  Operations Office Figure 6: Transfers from all sites in the last 90 days For ICHEP and the Upgrade efforts, we needed to produce and process record amounts of MC samples while supporting the very successful data-taking. This was a large burden, especially on the team members. Nevertheless the last three months were very successful and the total output was phenomenal, thanks to our dedicated site admins who keep the sites operational and the computing project members who spend countless hours nursing the...

  17. COMPUTING

    CERN Multimedia

    M. Kasemann

    Introduction A large fraction of the effort was focused during the last period into the preparation and monitoring of the February tests of Common VO Computing Readiness Challenge 08. CCRC08 is being run by the WLCG collaboration in two phases, between the centres and all experiments. The February test is dedicated to functionality tests, while the May challenge will consist of running at all centres and with full workflows. For this first period, a number of functionality checks of the computing power, data repositories and archives as well as network links are planned. This will help assess the reliability of the systems under a variety of loads, and identifying possible bottlenecks. Many tests are scheduled together with other VOs, allowing the full scale stress test. The data rates (writing, accessing and transfer¬ring) are being checked under a variety of loads and operating conditions, as well as the reliability and transfer rates of the links between Tier-0 and Tier-1s. In addition, the capa...

  18. COMPUTING

    CERN Multimedia

    Matthias Kasemann

    Overview The main focus during the summer was to handle data coming from the detector and to perform Monte Carlo production. The lessons learned during the CCRC and CSA08 challenges in May were addressed by dedicated PADA campaigns lead by the Integration team. Big improvements were achieved in the stability and reliability of the CMS Tier1 and Tier2 centres by regular and systematic follow-up of faults and errors with the help of the Savannah bug tracking system. In preparation for data taking the roles of a Computing Run Coordinator and regular computing shifts monitoring the services and infrastructure as well as interfacing to the data operations tasks are being defined. The shift plan until the end of 2008 is being put together. User support worked on documentation and organized several training sessions. The ECoM task force delivered the report on “Use Cases for Start-up of pp Data-Taking” with recommendations and a set of tests to be performed for trigger rates much higher than the ...

  19. COMPUTING

    CERN Multimedia

    P. MacBride

    The Computing Software and Analysis Challenge CSA07 has been the main focus of the Computing Project for the past few months. Activities began over the summer with the preparation of the Monte Carlo data sets for the challenge and tests of the new production system at the Tier-0 at CERN. The pre-challenge Monte Carlo production was done in several steps: physics generation, detector simulation, digitization, conversion to RAW format and the samples were run through the High Level Trigger (HLT). The data was then merged into three "Soups": Chowder (ALPGEN), Stew (Filtered Pythia) and Gumbo (Pythia). The challenge officially started when the first Chowder events were reconstructed on the Tier-0 on October 3rd. The data operations teams were very busy during the the challenge period. The MC production teams continued with signal production and processing while the Tier-0 and Tier-1 teams worked on splitting the Soups into Primary Data Sets (PDS), reconstruction and skimming. The storage sys...

  20. COMPUTING

    CERN Multimedia

    I. Fisk

    2013-01-01

    Computing operation has been lower as the Run 1 samples are completing and smaller samples for upgrades and preparations are ramping up. Much of the computing activity is focusing on preparations for Run 2 and improvements in data access and flexibility of using resources. Operations Office Data processing was slow in the second half of 2013 with only the legacy re-reconstruction pass of 2011 data being processed at the sites.   Figure 1: MC production and processing was more in demand with a peak of over 750 Million GEN-SIM events in a single month.   Figure 2: The transfer system worked reliably and efficiently and transferred on average close to 520 TB per week with peaks at close to 1.2 PB.   Figure 3: The volume of data moved between CMS sites in the last six months   The tape utilisation was a focus for the operation teams with frequent deletion campaigns from deprecated 7 TeV MC GEN-SIM samples to INVALID datasets, which could be cleaned up...

  1. COMPUTING

    CERN Multimedia

    I. Fisk

    2012-01-01

      Introduction Computing activity has been running at a sustained, high rate as we collect data at high luminosity, process simulation, and begin to process the parked data. The system is functional, though a number of improvements are planned during LS1. Many of the changes will impact users, we hope only in positive ways. We are trying to improve the distributed analysis tools as well as the ability to access more data samples more transparently.  Operations Office Figure 2: Number of events per month, for 2012 Since the June CMS Week, Computing Operations teams successfully completed data re-reconstruction passes and finished the CMSSW_53X MC campaign with over three billion events available in AOD format. Recorded data was successfully processed in parallel, exceeding 1.2 billion raw physics events per month for the first time in October 2012 due to the increase in data-parking rate. In parallel, large efforts were dedicated to WMAgent development and integrati...

  2. Retardo mental Mental retardation

    Directory of Open Access Journals (Sweden)

    Marcio M. Vasconcelos

    2004-04-01

    Full Text Available OBJETIVO: Esta revisão aborda as recentes descobertas da neurobiologia do retardo mental, enfatizando os novos recursos da citogenética, das técnicas moleculares e da neurorradiologia para esclarecer o diagnóstico. FONTES DE DADOS: O autor pesquisou o banco de dados MEDLINE da National Library of Medicine utilizando as palavras-chave "mental retardation", "developmental disability", "child" e "adolescent" em diferentes combinações, abrangendo o período de janeiro de 2000 a outubro de 2003. Também foram utilizados os bancos de dados das revistas científicas Pediatrics e New England Journal of Medicine através da palavra-chave "mental retardation". No total, o autor consultou cerca de 1.500 títulos de artigos e 500 resumos, e teve acesso direto a 150 artigos completos pertinentes. Quando oportuno, algumas referências dos artigos consultados também foram consideradas. O site Online Mendelian Inheritance in Man foi utilizado como fonte de informações em genética clínica. SÍNTESE DOS DADOS: Em outubro de 2003, o total de síndromes genéticas associadas a retardo mental chegou a 1.149. Considerando-se o conjunto das causas genéticas ou ambientais e congênitas ou adquiridas de retardo mental, a avaliação diagnóstica atual é capaz de esclarecer a etiologia em 50 a 70% dos casos. CONCLUSÕES: O autor sugere uma avaliação diagnóstica do retardo mental em etapas lógicas, visando ao uso racional dos dispendiosos recursos da citogenética, biologia molecular e neuroimagem.OBJECTIVE: This paper describes recent advances in the neurobiology of mental retardation, emphasizing new diagnostic resources provided by cytogenetics, molecular testing, and neuroimaging. SOURCES OF DATA: MEDLINE (January 2000 through October 2003, using the following key words: mental retardation, developmental disability, child, and adolescent. Search of the Pediatrics and New England Journal of Medicine websites using the key word mental retardation. The

  3. Phase change memory

    CERN Document Server

    Qureshi, Moinuddin K

    2011-01-01

    As conventional memory technologies such as DRAM and Flash run into scaling challenges, architects and system designers are forced to look at alternative technologies for building future computer systems. This synthesis lecture begins by listing the requirements for a next generation memory technology and briefly surveys the landscape of novel non-volatile memories. Among these, Phase Change Memory (PCM) is emerging as a leading contender, and the authors discuss the material, device, and circuit advances underlying this exciting technology. The lecture then describes architectural solutions t

  4. Systemic Lisbon Battery: Normative Data for Memory and Attention Assessments.

    Science.gov (United States)

    Gamito, Pedro; Morais, Diogo; Oliveira, Jorge; Ferreira Lopes, Paulo; Picareli, Luís Felipe; Matias, Marcelo; Correia, Sara; Brito, Rodrigo

    2016-05-04

    Memory and attention are two cognitive domains pivotal for the performance of instrumental activities of daily living (IADLs). The assessment of these functions is still widely carried out with pencil-and-paper tests, which lack ecological validity. The evaluation of cognitive and memory functions while the patients are performing IADLs should contribute to the ecological validity of the evaluation process. The objective of this study is to establish normative data from virtual reality (VR) IADLs designed to activate memory and attention functions. A total of 243 non-clinical participants carried out a paper-and-pencil Mini-Mental State Examination (MMSE) and performed 3 VR activities: art gallery visual matching task, supermarket shopping task, and memory fruit matching game. The data (execution time and errors, and money spent in the case of the supermarket activity) was automatically generated from the app. Outcomes were computed using non-parametric statistics, due to non-normality of distributions. Age, academic qualifications, and computer experience all had significant effects on most measures. Normative values for different levels of these measures were defined. Age, academic qualifications, and computer experience should be taken into account while using our VR-based platform for cognitive assessment purposes. ©Pedro Gamito, Diogo Morais, Jorge Oliveira, Paulo Ferreira Lopes, Luís Felipe Picareli, Marcelo Matias, Sara Correia, Rodrigo Brito. Originally published in JMIR Rehabilitation and Assistive Technology (http://rehab.jmir.org), 04.05.2016.

  5. COMPUTING

    CERN Multimedia

    I. Fisk

    2011-01-01

    Introduction The Computing Team successfully completed the storage, initial processing, and distribution for analysis of proton-proton data in 2011. There are still a variety of activities ongoing to support winter conference activities and preparations for 2012. Heavy ions The heavy-ion run for 2011 started in early November and has already demonstrated good machine performance and success of some of the more advanced workflows planned for 2011. Data collection will continue until early December. Facilities and Infrastructure Operations Operational and deployment support for WMAgent and WorkQueue+Request Manager components, routinely used in production by Data Operations, are provided. The GlideInWMS and components installation are now deployed at CERN, which is added to the GlideInWMS factory placed in the US. There has been new operational collaboration between the CERN team and the UCSD GlideIn factory operators, covering each others time zones by monitoring/debugging pilot jobs sent from the facto...

  6. Optical quantum memory

    Science.gov (United States)

    Lvovsky, Alexander I.; Sanders, Barry C.; Tittel, Wolfgang

    2009-12-01

    Quantum memory is essential for the development of many devices in quantum information processing, including a synchronization tool that matches various processes within a quantum computer, an identity quantum gate that leaves any state unchanged, and a mechanism to convert heralded photons to on-demand photons. In addition to quantum computing, quantum memory will be instrumental for implementing long-distance quantum communication using quantum repeaters. The importance of this basic quantum gate is exemplified by the multitude of optical quantum memory mechanisms being studied, such as optical delay lines, cavities and electromagnetically induced transparency, as well as schemes that rely on photon echoes and the off-resonant Faraday interaction. Here, we report on state-of-the-art developments in the field of optical quantum memory, establish criteria for successful quantum memory and detail current performance levels.

  7. Everyday memory and working memory in adolescents with mild intellectual disability

    NARCIS (Netherlands)

    van der Molen, M.J.; van Luit, J.E.H.; van der Molen, M.W.; Jongmans, M.J.

    2010-01-01

    Everyday memory and its relationship to working memory was investigated in adolescents with mild intellectual disability and compared to typically developing adolescents of the same age (CA) and younger children matched on mental age (MA). Results showed a delay on almost all memory measures for the

  8. Everyday Memory and Working Memory in Adolescents with Mild Intellectual Disability

    Science.gov (United States)

    Van der Molen, M. J.; Van Luit, J. E. H.; Van der Molen, Maurits W.; Jongmans, Marian J.

    2010-01-01

    Everyday memory and its relationship to working memory was investigated in adolescents with mild intellectual disability and compared to typically developing adolescents of the same age (CA) and younger children matched on mental age (MA). Results showed a delay on almost all memory measures for the adolescents with mild intellectual disability…

  9. Transactional Memory

    CERN Document Server

    Harris, Tim; Rajwar, Ravi

    2010-01-01

    The advent of multicore processors has renewed interest in the idea of incorporating transactions into the programming model used to write parallel programs.This approach, known as transactional memory, offers an alternative, and hopefully better, way to coordinate concurrent threads. The ACI(atomicity, consistency, isolation) properties of transactions provide a foundation to ensure that concurrent reads and writes of shared data do not produce inconsistent or incorrect results. At a higher level, a computation wrapped in a transaction executes atomically - either it completes successfullyand

  10. COMPUTING

    CERN Multimedia

    M. Kasemann

    CMS relies on a well functioning, distributed computing infrastructure. The Site Availability Monitoring (SAM) and the Job Robot submission have been very instrumental for site commissioning in order to increase availability of more sites such that they are available to participate in CSA07 and are ready to be used for analysis. The commissioning process has been further developed, including "lessons learned" documentation via the CMS twiki. Recently the visualization, presentation and summarizing of SAM tests for sites has been redesigned, it is now developed by the central ARDA project of WLCG. Work to test the new gLite Workload Management System was performed; a 4 times increase in throughput with respect to LCG Resource Broker is observed. CMS has designed and launched a new-generation traffic load generator called "LoadTest" to commission and to keep exercised all data transfer routes in the CMS PhE-DEx topology. Since mid-February, a transfer volume of about 12 P...

  11. Episodic memory in nonhuman animals.

    Science.gov (United States)

    Templer, Victoria L; Hampton, Robert R

    2013-09-09

    Episodic memories differ from other types of memory because they represent aspects of the past not present in other memories, such as the time, place, or social context in which the memories were formed. Focus on phenomenal experience in human memory, such as the sense of 'having been there', has resulted in conceptualizations of episodic memory that are difficult or impossible to apply to nonhuman species. It is therefore a significant challenge for investigators to agree on objective behavioral criteria that can be applied in nonhuman animals and still capture features of memory thought to be critical in humans. Some investigators have attempted to use neurobiological parallels to bridge this gap; however, defining memory types on the basis of the brain structures involved rather than on identified cognitive mechanisms risks missing crucial functional aspects of episodic memory, which are ultimately behavioral. The most productive way forward is likely a combination of neurobiology and sophisticated cognitive testing that identifies the mental representations present in episodic memory. Investigators that have refined their approach from asking the naïve question "do nonhuman animals have episodic memory" to instead asking "what aspects of episodic memory are shared by humans and nonhumans" are making progress. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Computer-Based Training in Math and Working Memory Improves Cognitive Skills and Academic Achievement in Primary School Children: Behavioral Results

    Directory of Open Access Journals (Sweden)

    Noelia Sánchez-Pérez

    2018-01-01

    Full Text Available Student academic achievement has been positively related to further development outcomes, such as the attainment of higher educational, employment, and socioeconomic aspirations. Among all the academic competences, mathematics has been identified as an essential skill in the field of international leadership as well as for those seeking positions in disciplines related to science, technology, and engineering. Given its positive consequences, studies have designed trainings to enhance children's mathematical skills. Additionally, the ability to regulate and control actions and cognitions, i.e., executive functions (EF, has been associated with school success, which has resulted in a strong effort to develop EF training programs to improve students' EF and academic achievement. The present study examined the efficacy of a school computer-based training composed of two components, namely, working memory and mathematics tasks. Among the advantages of using a computer-based training program is the ease with which it can be implemented in school settings and the ease by which the difficulty of the tasks can be adapted to fit the child's ability level. To test the effects of the training, children's cognitive skills (EF and IQ and their school achievement (math and language grades and abilities were evaluated. The results revealed a significant improvement in cognitive skills, such as non-verbal IQ and inhibition, and better school performance in math and reading among the children who participated in the training compared to those children who did not. Most of the improvements were related to training on WM tasks. These findings confirmed the efficacy of a computer-based training that combined WM and mathematics activities as part of the school routines based on the training's impact on children's academic competences and cognitive skills.

  13. Computer-Based Training in Math and Working Memory Improves Cognitive Skills and Academic Achievement in Primary School Children: Behavioral Results.

    Science.gov (United States)

    Sánchez-Pérez, Noelia; Castillo, Alejandro; López-López, José A; Pina, Violeta; Puga, Jorge L; Campoy, Guillermo; González-Salinas, Carmen; Fuentes, Luis J

    2017-01-01

    Student academic achievement has been positively related to further development outcomes, such as the attainment of higher educational, employment, and socioeconomic aspirations. Among all the academic competences, mathematics has been identified as an essential skill in the field of international leadership as well as for those seeking positions in disciplines related to science, technology, and engineering. Given its positive consequences, studies have designed trainings to enhance children's mathematical skills. Additionally, the ability to regulate and control actions and cognitions, i.e., executive functions (EF), has been associated with school success, which has resulted in a strong effort to develop EF training programs to improve students' EF and academic achievement. The present study examined the efficacy of a school computer-based training composed of two components, namely, working memory and mathematics tasks. Among the advantages of using a computer-based training program is the ease with which it can be implemented in school settings and the ease by which the difficulty of the tasks can be adapted to fit the child's ability level. To test the effects of the training, children's cognitive skills (EF and IQ) and their school achievement (math and language grades and abilities) were evaluated. The results revealed a significant improvement in cognitive skills, such as non-verbal IQ and inhibition, and better school performance in math and reading among the children who participated in the training compared to those children who did not. Most of the improvements were related to training on WM tasks. These findings confirmed the efficacy of a computer-based training that combined WM and mathematics activities as part of the school routines based on the training's impact on children's academic competences and cognitive skills.

  14. Mapping of the Underlying Neural Mechanisms of Maintenance and Manipulation in Visuo-Spatial Working Memory Using An n-back Mental Rotation Task: A Functional Magnetic Resonance Imaging Study.

    Science.gov (United States)

    Lamp, Gemma; Alexander, Bonnie; Laycock, Robin; Crewther, David P; Crewther, Sheila G

    2016-01-01

    Mapping of the underlying neural mechanisms of visuo-spatial working memory (WM) has been shown to consistently elicit activity in right hemisphere dominant fronto-parietal networks. However to date, the bulk of neuroimaging literature has focused largely on the maintenance aspect of visuo-spatial WM, with a scarcity of research into the aspects of WM involving manipulation of information. Thus, this study aimed to compare maintenance-only with maintenance and manipulation of visuo-spatial stimuli (3D cube shapes) utilizing a 1-back task while functional magnetic resonance imaging (fMRI) scans were acquired. Sixteen healthy participants (9 women, M = 23.94 years, SD = 2.49) were required to perform the 1-back task with or without mentally rotating the shapes 90° on a vertical axis. When no rotation was required (maintenance-only condition), a right hemispheric lateralization was revealed across fronto-parietal areas. However, when the task involved maintaining and manipulating the same stimuli through 90° rotation, activation was primarily seen in the bilateral parietal lobe and left fusiform gyrus. The findings confirm that the well-established right lateralized fronto-parietal networks are likely to underlie simple maintenance of visuo-spatial stimuli. The results also suggest that the added demand of manipulation of information maintained online appears to require further neural recruitment of functionally related areas. In particular mental rotation of visuospatial stimuli required bilateral parietal areas, and the left fusiform gyrus potentially to maintain a categorical or object representation. It can be concluded that WM is a complex neural process involving the interaction of an increasingly large network.

  15. How Can We Best Screen for Cognitive Impairment in Malaysia? A Pilot of the IDEA Cognitive Screen and Picture-Based Memory Impairment Scale and Comparison of Criterion Validity with the Mini Mental State Examination.

    Science.gov (United States)

    Rosli, Roshaslina; Tan, Maw Pin; Gray, William K; Subramanian, Pathmawathi; Mohd Hairi, Noran Naqiah; Chin, Ai-Vyrn

    2017-01-01

    To pilot two new cognitive screening tools for use in an urban Malaysian population and to compare their criterion validity against a gold standard, the well-established Mini-Mental State Examination (MMSE). The IDEA cognitive screen, Picture-based Memory Impairment Scale (PMIS), and MMSE were administered to a convenience sample of elderly (≥ 65 years) from the community and outpatient clinics at an urban teaching hospital. Consensus diagnosis was performed by two geriatricians blinded to PMIS and IDEA cognitive screen scores using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) clinical criteria. The MMSE performance was used as a reference. The study enrolled 66 participants, with a median age of 78.5 years (interquartile range [IQR], 72.5-83.0) years and 11.0 median years of education (IQR, 9.0-13.0). Forty-three (65.2%) were female, and 32 (48.4%) were Chinese. The area under the receiver operating characteristic (AUROC) curve values were .962 (IDEA cognitive screen), .970 (PMIS), and .935 (MMSE). The optimal cutoff values for sensitivity and specificity were: IDEA cognitive screen: ≤ 11, 90.9% and 89.7%; PMIS: ≤ 6, 97.3% and 69.0%; and MMSE: ≤ 23, 84.6% and 76.0%. Although the sample size was small, multivariable logistic regression modelling suggested that all three screen scores did not appear to be educationally biased. The IDEA and PMIS tools are potentially valid screening tools for dementia in urban Malaysia, and perform at least as well as the MMSE. Further work on larger representative, cohorts is needed to further assess the psychometric properties. Study provides alternative screening tools for dementia for both non-specialists and specialists.

  16. Learning and memory deficits consequent to reduction of the fragile X mental retardation protein result from metabotropic glutamate receptor-mediated inhibition of cAMP signaling in Drosophila.

    Science.gov (United States)

    Kanellopoulos, Alexandros K; Semelidou, Ourania; Kotini, Andriana G; Anezaki, Maria; Skoulakis, Efthimios M C

    2012-09-19

    Loss of the RNA-binding fragile X protein [fragile X mental retardation protein (FMRP)] results in a spectrum of cognitive deficits, the fragile X syndrome (FXS), while aging individuals with decreased protein levels present with a subset of these symptoms and tremor. The broad range of behavioral deficits likely reflects the ubiquitous distribution and multiple functions of the protein. FMRP loss is expected to affect multiple neuronal proteins and intracellular signaling pathways, whose identity and interactions are essential in understanding and ameliorating FXS symptoms. We used heterozygous mutants and targeted RNA interference-mediated abrogation in Drosophila to uncover molecular pathways affected by FMRP reduction. We present evidence that FMRP loss results in excess metabotropic glutamate receptor (mGluR) activity, attributable at least in part to elevation of the protein in affected neurons. Using high-resolution behavioral, genetic, and biochemical analyses, we present evidence that excess mGluR upon FMRP attenuation is linked to the cAMP decrement reported in patients and models, and underlies olfactory associative learning and memory deficits. Furthermore, our data indicate positive transcriptional regulation of the fly fmr1 gene by cAMP, via protein kinase A, likely through the transcription factor CREB. Because the human Fmr1 gene also contains CREB binding sites, the interaction of mGluR excess and cAMP signaling defects we present suggests novel combinatorial pharmaceutical approaches to symptom amelioration upon FMRP attenuation.

  17. Functional Neuroanatomy Involved in Automatic order Mental Arithmetic and Recitation of the Multiplication Table

    Science.gov (United States)

    Wang, Li-Qun; Saito, Masao

    We used 1.5T functional magnetic resonance imaging (fMRI) to explore that which brain areas contribute uniquely to numeric computation. The BOLD effect activation pattern of metal arithmetic task (successive subtraction: actual calculation task) was compared with multiplication tables repetition task (rote verbal arithmetic memory task) response. The activation found in right parietal lobule during metal arithmetic task suggested that quantitative cognition or numeric computation may need the assistance of sensuous convert, such as spatial imagination and spatial sensuous convert. In addition, this mechanism may be an ’analog algorithm’ in the simple mental arithmetic processing.

  18. Progress In Optical Memory Technology

    Science.gov (United States)

    Tsunoda, Yoshito

    1987-01-01

    More than 20 years have passed since the concept of optical memory was first proposed in 1966. Since then considerable progress has been made in this area together with the creation of completely new markets of optical memory in consumer and computer application areas. The first generation of optical memory was mainly developed with holographic recording technology in late 1960s and early 1970s. Considerable number of developments have been done in both analog and digital memory applications. Unfortunately, these technologies did not meet a chance to be a commercial product. The second generation of optical memory started at the beginning of 1970s with bit by bit recording technology. Read-only type optical memories such as video disks and compact audio disks have extensively investigated. Since laser diodes were first applied to optical video disk read out in 1976, there have been extensive developments of laser diode pick-ups for optical disk memory systems. The third generation of optical memory started in 1978 with bit by bit read/write technology using laser diodes. Developments of recording materials including both write-once and erasable have been actively pursued at several research institutes. These technologies are mainly focused on the optical memory systems for computer application. Such practical applications of optical memory technology has resulted in the creation of such new products as compact audio disks and computer file memories.

  19. Subcortical hyperintensity volumetrics in Alzheimer's disease and normal elderly in the Sunnybrook Dementia Study: correlations with atrophy, executive function, mental processing speed, and verbal memory.

    Science.gov (United States)

    Ramirez, Joel; McNeely, Alicia A; Scott, Christopher Jm; Stuss, Donald T; Black, Sandra E

    2014-01-01

    Subcortical hyperintensities (SHs) are radiological entities commonly observed on magnetic resonance imaging (MRI) of patients with Alzheimer's disease (AD) and normal elderly controls. Although the presence of SH is believed to indicate some form of subcortical vasculopathy, pathological heterogeneity, methodological differences, and the contribution of brain atrophy associated with AD pathology have yielded inconsistent results in the literature. Using the Lesion Explorer (LE) MRI processing pipeline for SH quantification and brain atrophy, this study examined SH volumes of interest and cognitive function in a sample of patients with AD (n = 265) and normal elderly controls (n = 100) from the Sunnybrook Dementia Study. Compared with healthy controls, patients with AD were found to have less gray matter, less white matter, and more sulcal and ventricular cerebrospinal fluid (all significant, P deep white SH (dwSH) (P processing speed (P memory (P <0.01) in patients with AD. These brain-behavior relationships and correlations with brain atrophy suggest that subtle, yet measurable, signs of small vessel disease may have potential clinical relevance as targets for treatment in Alzheimer's dementia.

  20. Mental Disorders

    Science.gov (United States)

    Mental disorders include a wide range of problems, including Anxiety disorders, including panic disorder, obsessive-compulsive disorder, ... disorders, including schizophrenia There are many causes of mental disorders. Your genes and family history may play ...

  1. Mental Health

    Science.gov (United States)

    Mental health includes our emotional, psychological, and social well-being. It affects how we think, feel and act as ... stress, relate to others, and make choices. Mental health is important at every stage of life, from ...

  2. MEMORY MODULATION

    Science.gov (United States)

    Roozendaal, Benno; McGaugh, James L.

    2011-01-01

    Our memories are not all created equally strong: Some experiences are well remembered while others are remembered poorly, if at all. Research on memory modulation investigates the neurobiological processes and systems that contribute to such differences in the strength of our memories. Extensive evidence from both animal and human research indicates that emotionally significant experiences activate hormonal and brain systems that regulate the consolidation of newly acquired memories. These effects are integrated through noradrenergic activation of the basolateral amygdala which regulates memory consolidation via interactions with many other brain regions involved in consolidating memories of recent experiences. Modulatory systems not only influence neurobiological processes underlying the consolidation of new information, but also affect other mnemonic processes, including memory extinction, memory recall and working memory. In contrast to their enhancing effects on consolidation, adrenal stress hormones impair memory retrieval and working memory. Such effects, as with memory consolidation, require noradrenergic activation of the basolateral amygdala and interactions with other brain regions. PMID:22122145

  3. Memory Matters

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Memory Matters KidsHealth / For Kids / Memory Matters What's in ... of your complex and multitalented brain. What Is Memory? When an event happens, when you learn something, ...

  4. The parallel processing of EGS4 code on distributed memory scalar parallel computer:Intel Paragon XP/S15-256

    Energy Technology Data Exchange (ETDEWEB)

    Takemiya, Hiroshi; Ohta, Hirofumi; Honma, Ichirou

    1996-03-01

    The parallelization of Electro-Magnetic Cascade Monte Carlo Simulation Code, EGS4 on distributed memory scalar parallel computer: Intel Paragon XP/S15-256 is described. EGS4 has the feature that calculation time for one incident particle is quite different from each other because of the dynamic generation of secondary particles and different behavior of each particle. Granularity for parallel processing, parallel programming model and the algorithm of parallel random number generation are discussed and two kinds of method, each of which allocates particles dynamically or statically, are used for the purpose of realizing high speed parallel processing of this code. Among four problems chosen for performance evaluation, the speedup factors for three problems have been attained to nearly 100 times with 128 processor. It has been found that when both the calculation time for each incident particles and its dispersion are large, it is preferable to use dynamic particle allocation method which can average the load for each processor. And it has also been found that when they are small, it is preferable to use static particle allocation method which reduces the communication overhead. Moreover, it is pointed out that to get the result accurately, it is necessary to use double precision variables in EGS4 code. Finally, the workflow of program parallelization is analyzed and tools for program parallelization through the experience of the EGS4 parallelization are discussed. (author).

  5. Sparse distributed memory overview

    Science.gov (United States)

    Raugh, Mike

    1990-01-01

    The Sparse Distributed Memory (SDM) project is investigating the theory and applications of massively parallel computing architecture, called sparse distributed memory, that will support the storage and retrieval of sensory and motor patterns characteristic of autonomous systems. The immediate objectives of the project are centered in studies of the memory itself and in the use of the memory to solve problems in speech, vision, and robotics. Investigation of methods for encoding sensory data is an important part of the research. Examples of NASA missions that may benefit from this work are Space Station, planetary rovers, and solar exploration. Sparse distributed memory offers promising technology for systems that must learn through experience and be capable of adapting to new circumstances, and for operating any large complex system requiring automatic monitoring and control. Sparse distributed memory is a massively parallel architecture motivated by efforts to understand how the human brain works. Sparse distributed memory is an associative memory, able to retrieve information from cues that only partially match patterns stored in the memory. It is able to store long temporal sequences derived from the behavior of a complex system, such as progressive records of the system's sensory data and correlated records of the system's motor controls.

  6. The neurobiology of the human memory.

    Science.gov (United States)

    Fietta, Pierluigi; Fietta, Pieranna

    2011-01-01

    Memory can be defined as the ability to acquire, process, store, and retrieve information. Memory is indispensable for learning, adaptation, and survival of every living organism. In humans, the remembering process has acquired great flexibility and complexity, reaching close links with other mental functions, such as thinking and emotions. Changes in synaptic connectivity and interactions among multiple neural networks provide the neurobiological substrates for memory encoding, retention, and consolidation. Memory may be categorized as short-term and long-term memory (according to the storage temporal duration), as implicit and explicit memory (with respect to the consciousness of remembering), as declarative (knowing that [fact]) and procedural (knowing how [skill]) memory, or as sensory (echoic, iconic and haptil), semantic, and episodic memory (according to the various remembering domains). Significant advances have been obtained in understanding memory neurobiology, but much remains to be learned in its cognitive, psychological, and phenomenological aspects.

  7. Mental Illness

    Science.gov (United States)

    ... the same time. For example, you may have depression and a substance use disorder. Complications Mental illness is a leading cause of disability. Untreated mental illness can cause severe emotional, behavioral and physical health problems. Complications sometimes linked to mental illness include: ...

  8. Time-Predictable Virtual Memory

    DEFF Research Database (Denmark)

    Puffitsch, Wolfgang; Schoeberl, Martin

    2016-01-01

    Virtual memory is an important feature of modern computer architectures. For hard real-time systems, memory protection is a particularly interesting feature of virtual memory. However, current memory management units are not designed for time-predictability and therefore cannot be used...... in such systems. This paper investigates the requirements on virtual memory from the perspective of hard real-time systems and presents the design of a time-predictable memory management unit. Our evaluation shows that the proposed design can be implemented efficiently. The design allows address translation...... and address range checking in constant time of two clock cycles on a cache miss. This constant time is in strong contrast to the possible cost of a miss in a translation look-aside buffer in traditional virtual memory organizations. Compared to a platform without a memory management unit, these two additional...

  9. Visual and Haptic Mental Rotation

    Directory of Open Access Journals (Sweden)

    Satoshi Shioiri

    2011-10-01

    Full Text Available It is well known that visual information can be retained in several types of memory systems. Haptic information can also be retained in a memory because we can repeat a hand movement. There may be a common memory system for vision and action. On the one hand, it may be convenient to have a common system for acting with visual information. On the other hand, different modalities may have their own memory and use retained information without transforming specific to the modality. We compared memory properties of visual and haptic information. There is a phenomenon known as mental rotation, which is possibly unique to visual representation. The mental rotation is a phenomenon where reaction time increases with the angle of visual target (eg,, a letter to identify. The phenomenon is explained by the difference in time to rotate the representation of the target in the visual sytem. In this study, we compared the effect of stimulus angle on visual and haptic shape identification (two-line shapes were used. We found that a typical effect of mental rotation for the visual stimulus. However, no such effect was found for the haptic stimulus. This difference cannot be explained by the modality differences in response because similar difference was found even when haptical response was used for visual representation and visual response was used for haptic representation. These results indicate that there are independent systems for visual and haptic representations.

  10. Avaliação da cognição de mulheres no climatério com o Mini-Exame do Estado Mental e o Teste de Memória da Lista de Palavras Cognitive function in menopausal women evaluated with the Mini-Mental State Examination and Word-List Memory Test

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Leite Fernandes

    2009-09-01

    Full Text Available No Brasil, há pouca investigação sobre cognição no climatério, apesar da grande freqüência de queixas neuropsíquicas nessa fase da vida feminina. Apresentamos estudo transversal, cujo objetivo foi descrever os escores de 156 mulheres climatéricas no Mini-Exame do Estado Mental (MEEM e no Teste de Memória da Lista de Palavras (TMLP. A média obtida no MEEM foi de 25,86 pontos (DP = 2,67, semelhante a outros estudos, exceto pelo melhor desempenho das analfabetas; os escores nos subitens "atenção e cálculo" e "memória imediata" apresentaram valores inferiores. No TMLP, a média também foi condizente com a literatura (18,83 palavras; DP = 3,82. As únicas associações significativas com as pontuações foram a escolaridade em ambos os testes e a hipertensão arterial no TMLP. Concluímos que o desempenho cognitivo dessas mulheres climatéricas se assemelha ao de outras amostras brasileiras, confirmando-se, inclusive, a maior variabilidade de pontuação entre indivíduos de baixa escolaridade. As queixas de dificuldades de memória na meia-idade feminina podem estar relacionadas à redução da sua atenção.There is little research in Brazil on cognition and menopause, despite the high frequency of neuropsychiatric complaints in this phase of women's life. The authors present a cross-sectional study aimed at describing the scores by 156 menopausal women on the Mini-Mental State Examination (MMSE and the Word-List Memory Test (WLMT. The mean score on the MMSE was 25.86 points (SD = 2.67, similar to other studies, except for better performance by illiterate women; scores on the sub-items "attention and calculation" and "immediate recall" showed lower values. In the WLMT, the mean was also consistent with the literature (M = 18.83 words; SD = 3.82. The only significant associations with score were for schooling in both tests and arterial hypertension in the WLMT. The authors conclude that cognitive performance in these menopausal

  11. Recall, Recognition, and the Measurement of Memory for Print Advertisements

    OpenAIRE

    Richard P. Bagozzi; Alvin J. Silk

    1983-01-01

    The recall and recognition of people for 95 print ads were examined with an aim toward investigating memory structure and decay processes. It was found that recall and recognition do not, by themselves, measure a single underlying memory state. Rather, memory is multidimensional, and recall and recognition capture only a portion of memory, while at the same time reflecting other mental states. When interest in the ads was held constant, however, recall and recognition did measure memory as a ...

  12. The Influence of Colour on Memory Performance: A Review

    OpenAIRE

    Dzulkifli, Mariam Adawiah; Mustafar, Muhammad Faiz

    2013-01-01

    Human cognition involves many mental processes that are highly interrelated, such as perception, attention, memory, and thinking. An important and core cognitive process is memory, which is commonly associated with the storing and remembering of environmental information. An interesting issue in memory research is on ways to enhance memory performance, and thus, remembering of information. Can colour result in improved memory abilities? The present paper highlights the relationship between co...

  13. Exploring memory hierarchy design with emerging memory technologies

    CERN Document Server

    Sun, Guangyu

    2014-01-01

    This book equips readers with tools for computer architecture of high performance, low power, and high reliability memory hierarchy in computer systems based on emerging memory technologies, such as STTRAM, PCM, FBDRAM, etc.  The techniques described offer advantages of high density, near-zero static power, and immunity to soft errors, which have the potential of overcoming the “memory wall.”  The authors discuss memory design from various perspectives: emerging memory technologies are employed in the memory hierarchy with novel architecture modification;  hybrid memory structure is introduced to leverage advantages from multiple memory technologies; an analytical model named “Moguls” is introduced to explore quantitatively the optimization design of a memory hierarchy; finally, the vulnerability of the CMPs to radiation-based soft errors is improved by replacing different levels of on-chip memory with STT-RAMs.   ·         Provides a holistic study of using emerging memory technologies i...

  14. How Human Memory and Working Memory Work in Second Language Acquisition

    OpenAIRE

    小那覇, 洋子; Onaha, Hiroko

    2014-01-01

    We often draw an analogy between human memory and computers. Information around us is taken into our memory storage first, and then we use the information in storage whatever we need it in our daily life. Linguistic information is also in storage and we process our thoughts based on the memory that is stored. Memory storage consists of multiple memory systems; one of which is called working memory that includes short-term memory. Working memory is the central system that underpins the process...

  15. 心算教學活動實踐於小一數學課室之研究 Mental Computation Activity Implementation into First-Grade Mathematics Classes

    Directory of Open Access Journals (Sweden)

    楊德清 Der-Ching Yang

    2012-06-01

    Full Text Available 本研究採質性研究法探討國小一年級學生進行心算教學活動之成效、策略改變情形及教學活動的實施歷程。研究樣本為實驗組學生21 人,進行二位數加減一位數的心算策略教學。對照組學生16人,依照教科書規劃的方式進行二位數加減一位數的教學,兩班各進行12 節課教學。研究結果顯示:教學後實驗組學生在心算之表現顯著優於對照組學生。同時,結果亦顯示教學後實驗組學生能夠發展多元之解題策略,如分離策略、集合策略,以及整體策略等。相反地,對照組學生在教學前、後,所使用之策略以數數策略、圖像與直式心像為主,改變較少,且少有心算策略的使用。教學過程中,藉由高分組學生的回答帶動中分組與低分組學生的思考,同時學生對於能夠上臺分享自己的策略感到興奮。最後根據研究結果,針對心算教學活動融入一年級數學課程及未來研究提出建議。 This study employs a qualitative approach to investigate the effect of mental computation activities integrated into first-grade mathematics classes. The mental computation activities, including 2-digit addition and subtraction problems, were used in an experimental group comprising 21 students. The control group comprised 16 students who were following textbook activities, including 2-digit addition and subtraction problems. The teaching intervention lasted for 12 periods for both groups. The results show that students in the experimental group experienced improved performance for mental computation than students in the control group following intervention. Additionally, data indicate that students in the experimental group can develop and use multiple mental strategies, such as separation, aggregation, and holistic strategies following intervention. Conversely, students in the control group preferred using counting and pictorial

  16. A Ternary Hybrid EEG-NIRS Brain-Computer Interface for the Classification of Brain Activation Patterns during Mental Arithmetic, Motor Imagery, and Idle State.

    Science.gov (United States)

    Shin, Jaeyoung; Kwon, Jinuk; Im, Chang-Hwan

    2018-01-01

    The performance of a brain-computer interface (BCI) can be enhanced by simultaneously using two or more modalities to record brain activity, which is generally referred to as a hybrid BCI. To date, many BCI researchers have tried to implement a hybrid BCI system by combining electroencephalography (EEG) and functional near-infrared spectroscopy (NIRS) to improve the overall accuracy of binary classification. However, since hybrid EEG-NIRS BCI, which will be denoted by hBCI in this paper, has not been applied to ternary classification problems, paradigms and classification strategies appropriate for ternary classification using hBCI are not well investigated. Here we propose the use of an hBCI for the classification of three brain activation patterns elicited by mental arithmetic, motor imagery, and idle state, with the aim to elevate the information transfer rate (ITR) of hBCI by increasing the number of classes while minimizing the loss of accuracy. EEG electrodes were placed over the prefrontal cortex and the central cortex, and NIRS optodes were placed only on the forehead. The ternary classification problem was decomposed into three binary classification problems using the "one-versus-one" (OVO) classification strategy to apply the filter-bank common spatial patterns filter to EEG data. A 10 × 10-fold cross validation was performed using shrinkage linear discriminant analysis (sLDA) to evaluate the average classification accuracies for EEG-BCI, NIRS-BCI, and hBCI when the meta-classification method was adopted to enhance classification accuracy. The ternary classification accuracies for EEG-BCI, NIRS-BCI, and hBCI were 76.1 ± 12.8, 64.1 ± 9.7, and 82.2 ± 10.2%, respectively. The classification accuracy of the proposed hBCI was thus significantly higher than those of the other BCIs ( p < 0.005). The average ITR for the proposed hBCI was calculated to be 4.70 ± 1.92 bits/minute, which was 34.3% higher than that reported for a previous binary hBCI study.

  17. Taxing Working Memory during Retrieval of Emotional Memories Does Not Reduce Memory Accessibility When Cued with Reminders

    NARCIS (Netherlands)

    van Schie, Kevin; Engelhard, Iris M; van den Hout, Marcel A

    2015-01-01

    Earlier studies have shown that when individuals recall an emotional memory while simultaneously doing a demanding dual-task [e.g., playing Tetris, mental arithmetic, making eye movements (EM)], this reduces self-reported vividness and emotionality of the memory. These effects have been found up to

  18. Memory in autistic spectrum disorder.

    Science.gov (United States)

    Boucher, Jill; Mayes, Andrew; Bigham, Sally

    2012-05-01

    Behavioral evidence concerning memory in forms of high-functioning autism (HFA) and in moderately low-functioning autism (M-LFA) is reviewed and compared. Findings on M-LFA are sparse. However, it is provisionally concluded that memory profiles in HFA and M-LFA (relative to ability-matched controls) are similar but that declarative memory impairments are more extensive in M-LFA than in HFA. Specifically, both groups have diminished memory for emotion- or person-related stimuli. Regarding memory for nonsocial stimuli, both groups probably have mental-age-appropriate nondeclarative memory, and within declarative memory, both groups have mental-age-appropriate immediate free recall of within-span or supraspan lists of unrelated items, as well as cued recall and paired associate learning. By contrast, recognition is largely unimpaired in HFA but moderately impaired in M-LFA, and free recall of meaningful or structured stimuli is moderately impaired in HFA but more severely impaired in M-LFA. Theoretical explanations of data on declarative memory in HFA identify problems in the integrative processing, or the consolidation and storage, of complex stimuli or a specific problem of recollection. Proposed neural substrates include the following: disconnectivity of primary sensory and association areas; dysfunctions of medial prefrontal cortex, hippocampus, or posterior parietal lobe; or combinations of these associated with neural disconnectivity. Hypothetically, perirhinal dysfunction might explain the more extensive declarative memory impairments in M-LFA. Foreseeable consequences of uneven memory abilities in HFA and M-LFA are outlined, including possible effects on language and learning in M-LFA. Finally, priorities for future research are identified, highlighting the urgent need for research on memory in lower functioning individuals. 2012 APA, all rights reserved

  19. Computer programming and computer systems

    CERN Document Server

    Hassitt, Anthony

    1966-01-01

    Computer Programming and Computer Systems imparts a "reading knowledge? of computer systems.This book describes the aspects of machine-language programming, monitor systems, computer hardware, and advanced programming that every thorough programmer should be acquainted with. This text discusses the automatic electronic digital computers, symbolic language, Reverse Polish Notation, and Fortran into assembly language. The routine for reading blocked tapes, dimension statements in subroutines, general-purpose input routine, and efficient use of memory are also elaborated.This publication is inten

  20. Working Memory Intervention: A Reading Comprehension Approach

    Science.gov (United States)

    Perry, Tracy L.; Malaia, Evguenia

    2013-01-01

    For any complex mental task, people rely on working memory. Working memory capacity (WMC) is one predictor of success in learning. Historically, attempts to improve verbal WM through training have not been effective. This study provided elementary students with WM consolidation efficiency training to answer the question, Can reading comprehension…

  1. The scopolamine-reversal paradigm in rats and monkeys: the importance of computer-assisted operant-conditioning memory tasks for screening drug candidates.

    Science.gov (United States)

    Buccafusco, Jerry J; Terry, Alvin V; Webster, Scott J; Martin, Daniel; Hohnadel, Elizabeth J; Bouchard, Kristy A; Warner, Samantha E

    2008-08-01

    The scopolamine-reversal model is enjoying a resurgence of interest in clinical studies as a reversible pharmacological model for Alzheimer's disease (AD). The cognitive impairment associated with scopolamine is similar to that in AD. The scopolamine model is not simply a cholinergic model, as it can be reversed by drugs that are noncholinergic cognition-enhancing agents. The objective of the study was to determine relevance of computer-assisted operant-conditioning tasks in the scopolamine-reversal model in rats and monkeys. Rats were evaluated for their acquisition of a spatial reference memory task in the Morris water maze. A separate cohort was proficient in performance of an automated delayed stimulus discrimination task (DSDT). Rhesus monkeys were proficient in the performance of an automated delayed matching-to-sample task (DMTS). The AD drug donepezil was evaluated for its ability to reverse the decrements in accuracy induced by scopolamine administration in all three tasks. In the DSDT and DMTS tasks, the effects of donepezil were delay (retention interval)-dependent, affecting primarily short delay trials. Donepezil produced significant but partial reversals of the scopolamine-induced impairment in task accuracies after 2 mg/kg in the water maze, after 1 mg/kg in the DSDT, and after 50 microg/kg in the DMTS task. The two operant-conditioning tasks (DSDT and DMTS) provided data most in keeping with those reported in clinical studies with these drugs. The model applied to nonhuman primates provides an excellent transitional model for new cognition-enhancing drugs before clinical trials.

  2. Method and apparatus for managing access to a memory

    Science.gov (United States)

    DeBenedictis, Erik

    2017-08-01

    A method and apparatus for managing access to a memory of a computing system. A controller transforms a plurality of operations that represent a computing job into an operational memory layout that reduces a size of a selected portion of the memory that needs to be accessed to perform the computing job. The controller stores the operational memory layout in a plurality of memory cells within the selected portion of the memory. The controller controls a sequence by which a processor in the computing system accesses the memory to perform the computing job using the operational memory layout. The operational memory layout reduces an amount of energy consumed by the processor to perform the computing job.

  3. Memory and Its Effect on Adult Function

    Directory of Open Access Journals (Sweden)

    Shokouh Navvabi-Nejad

    2000-07-01

    Full Text Available Memory capabilities, including its mechanisms and memory approaches weaken as age increases. However, the studies reveal that the content of memory, i.e. the knowledge stored in it, usually increases. Memory system includes sensory memory within which environmental information are recorded. Short-term memory is related to storing data at awareness level, whereas long-term memory is associated with  storing knowledge and past experiences. Psychological and physiological factors such as mental and physical health, nutrition, using narcotic substances and alcohol, and also stimulation during life may affect all functions of the elderly such as their memory. Unfortunately, many researchers overlooked the effects of these variables on subjects.

  4. Memory for details with self-referencing.

    Science.gov (United States)

    Serbun, Sarah J; Shih, Joanne Y; Gutchess, Angela H

    2011-11-01

    Self-referencing benefits item memory, but little is known about the ways in which referencing the self affects memory for details. Experiment 1 assessed whether the effects of self-referencing operate only at the item, or general, level or whether they also enhance memory for specific visual details of objects. Participants incidentally encoded objects by making judgements in reference to the self, a close other (one's mother), or a familiar other (Bill Clinton). Results indicate that referencing the self or a close other enhances both specific and general memory. Experiments 2 and 3 assessed verbal memory for source in a task that relied on distinguishing between different mental operations (internal sources). The results indicate that self-referencing disproportionately enhances source memory, relative to conditions referencing other people, semantic, or perceptual information. We conclude that self-referencing not only enhances specific memory for both visual and verbal information, but can also disproportionately improve memory for specific internal source details.

  5. Stress, memory, and the hippocampus.

    Science.gov (United States)

    Wingenfeld, Katja; Wolf, Oliver T

    2014-01-01

    Stress hormones, i.e. cortisol in human and cortisone in rodents, influence a wide range of cognitive functions, including hippocampus-based declarative memory performance. Cortisol enhances memory consolidation, but impairs memory retrieval. In this context glucocorticoid receptor sensitivity and hippocampal integrity play an important role. This review integrates findings on the relationships between the hypothalamus-pituitary-adrenal (HPA) axis, one of the main coordinators of the stress response, hippocampus, and memory. Findings obtained in healthy participants will be compared with selected mental disorders, including major depressive disorder (MDD), posttraumatic stress disorder (PTSD), and borderline personality disorder (BPD). These disorders are characterized by alterations of the HPA axis and hippocampal dysfunctions. Interestingly, the acute effects of stress hormones on memory in psychiatric patients are different from those found in healthy humans. While cortisol administration has failed to affect memory retrieval in patients with MDD, patients with PTSD and BPD have been found to show enhanced rather than impaired memory retrieval after hydrocortisone. This indicates an altered sensitivity to stress hormones in these mental disorders. © 2014 S. Karger AG, Basel

  6. Mental Health

    Science.gov (United States)

    ... well Feeling guilty, worthless, or helpless Thinking about suicide or hurting yourself Other mental health conditions include anxiety disorders, mood disorders, and personality disorders. For a good description ...

  7. A Computational Framework for Planning Therapeutical Sessions aimed to Support the Prevention and Treatment of Mental Health Disorders using Emotional Virtual Agents

    OpenAIRE

    BRESÓ GUARDADO, ADRIÁN

    2016-01-01

    [EN] Interaction is defined as the realization of a reciprocal action between two or more people or things. Particularly in computer science, the term interaction refers to the discipline that studies the exchange of information between people and computers, and is generally known by the term Human-Computer Interaction (HCI). Good design decisions and an adequate development of the software is required for efficient HCI to facilitate the acceptability of computer-based applications by the...

  8. Extended memory management under RTOS

    Science.gov (United States)

    Plummer, M.

    1981-01-01

    A technique for extended memory management in ROLM 1666 computers using FORTRAN is presented. A general software system is described for which the technique can be ideally applied. The memory manager interface with the system is described. The protocols by which the manager is invoked are presented, as well as the methods used by the manager.

  9. Josephson Thermal Memory

    Science.gov (United States)

    Guarcello, Claudio; Solinas, Paolo; Braggio, Alessandro; Di Ventra, Massimiliano; Giazotto, Francesco

    2018-01-01

    We propose a superconducting thermal memory device that exploits the thermal hysteresis in a flux-controlled temperature-biased superconducting quantum-interference device (SQUID). This system reveals a flux-controllable temperature bistability, which can be used to define two well-distinguishable thermal logic states. We discuss a suitable writing-reading procedure for these memory states. The time of the memory writing operation is expected to be on the order of approximately 0.2 ns for a Nb-based SQUID in thermal contact with a phonon bath at 4.2 K. We suggest a noninvasive readout scheme for the memory states based on the measurement of the effective resonance frequency of a tank circuit inductively coupled to the SQUID. The proposed device paves the way for a practical implementation of thermal logic and computation. The advantage of this proposal is that it represents also an example of harvesting thermal energy in superconducting circuits.

  10. THEORETICAL REVIEW The Hippocampus, Time, and Memory Across Scales

    Science.gov (United States)

    Howard, Marc W.; Eichenbaum, Howard

    2014-01-01

    A wealth of experimental studies with animals have offered insights about how neural networks within the hippocampus support the temporal organization of memories. These studies have revealed the existence of “time cells” that encode moments in time, much as the well-known “place cells” map locations in space. Another line of work inspired by human behavioral studies suggests that episodic memories are mediated by a state of temporal context that changes gradually over long time scales, up to at least a few thousand seconds. In this view, the “mental time travel” hypothesized to support the experience of episodic memory corresponds to a “jump back in time” in which a previous state of temporal context is recovered. We suggest that these 2 sets of findings could be different facets of a representation of temporal history that maintains a record at the last few thousand seconds of experience. The ability to represent long time scales comes at the cost of discarding precise information about when a stimulus was experienced—this uncertainty becomes greater for events further in the past. We review recent computational work that describes a mechanism that could construct such a scale-invariant representation. Taken as a whole, this suggests the hippocampus plays its role in multiple aspects of cognition by representing events embedded in a general spatiotemporal context. The representation of internal time can be useful across nonhippocampal memory systems. PMID:23915126

  11. Mental health informatics

    CERN Document Server

    Song, Insu; Yellowlees, Peter; Diederich, Joachim

    2014-01-01

    This book introduces approaches that have the potential to transform the daily practice of psychiatrists and psychologists. This includes the asynchronous communication between mental health care providers and clients as well as the automation of assessment and therapy. Speech and language are particularly interesting from the viewpoint of psychological assessment. For instance, depression may change the characteristics of voice in individuals and these changes can be detected by a special form of speech analysis. Computational screening methods that utilise speech and language can detect subtle changes and alert clinicians as well as individuals and caregivers. The use of online technologies in mental health, however, poses ethical problems that will occupy concerned individuals, governments and the wider public for some time. Assuming that these ethical problems can be solved, it should be possible to diagnose and treat mental health disorders online (excluding the use of medication).

  12. Topological Schemas of Memory Spaces

    Science.gov (United States)

    Babichev, Andrey; Dabaghian, Yuri A.

    2018-01-01

    Hippocampal cognitive map—a neuronal representation of the spatial environment—is widely discussed in the computational neuroscience literature for decades. However, more recent studies point out that hippocampus plays a major role in producing yet another cognitive framework—the memory space—that incorporates not only spatial, but also non-spatial memories. Unlike the cognitive maps, the memory spaces, broadly understood as “networks of interconnections among the representations of events,” have not yet been studied from a theoretical perspective. Here we propose a mathematical approach that allows modeling memory spaces constructively, as epiphenomena of neuronal spiking activity and thus to interlink several important notions of cognitive neurophysiology. First, we suggest that memory spaces have a topological nature—a hypothesis that allows treating both spatial and non-spatial aspects of hippocampal function on equal footing. We then model the hippocampal memory spaces in different environments and demonstrate that the resulting constructions naturally incorporate the corresponding cognitive maps and provide a wider context for interpreting spatial information. Lastly, we propose a formal description of the memory consolidation process that connects memory spaces to the Morris' cognitive schemas-heuristic representations of the acquired memories, used to explain the dynamics of learning and memory consolidation in a given environment. The proposed approach allows evaluating these constructs as the most compact representations of the memory space's structure. PMID:29740306

  13. Topological Schemas of Memory Spaces

    Directory of Open Access Journals (Sweden)

    Andrey Babichev

    2018-04-01

    Full Text Available Hippocampal cognitive map—a neuronal representation of the spatial environment—is widely discussed in the computational neuroscience literature for decades. However, more recent studies point out that hippocampus plays a major role in producing yet another cognitive framework—the memory space—that incorporates not only spatial, but also non-spatial memories. Unlike the cognitive maps, the memory spaces, broadly understood as “networks of interconnections among the representations of events,” have not yet been studied from a theoretical perspective. Here we propose a mathematical approach that allows modeling memory spaces constructively, as epiphenomena of neuronal spiking activity and thus to interlink several important notions of cognitive neurophysiology. First, we suggest that memory spaces have a topological nature—a hypothesis that allows treating both spatial and non-spatial aspects of hippocampal function on equal footing. We then model the hippocampal memory spaces in different environments and demonstrate that the resulting constructions naturally incorporate the corresponding cognitive maps and provide a wider context for interpreting spatial information. Lastly, we propose a formal description of the memory consolidation process that connects memory spaces to the Morris' cognitive schemas-heuristic representations of the acquired memories, used to explain the dynamics of learning and memory consolidation in a given environment. The proposed approach allows evaluating these constructs as the most compact representations of the memory space's structure.

  14. Cognitive Training Program to Improve Working Memory in Older Adults with MCI.

    Science.gov (United States)

    Hyer, Lee; Scott, Ciera; Atkinson, Mary Michael; Mullen, Christine M; Lee, Anna; Johnson, Aaron; Mckenzie, Laura C

    2016-01-01

    Deficits in working memory (WM) are associated with age-related decline. We report findings from a clinical trial that examined the effectiveness of Cogmed, a computerized program that trains WM. We compare this program to a Sham condition in older adults with Mild Cognitive Impairment (MCI). Older adults (N = 68) living in the community were assessed. Participants reported memory impairment and met criteria for MCI, either by poor delayed memory or poor performance in other cognitive areas. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS, Delayed Memory Index) and the Clinical Dementia Rating scale (CDR) were utilized. All presented with normal Mini Mental State Exams (MMSE) and activities of daily living (ADLs). Participants were randomized to Cogmed or a Sham computer program. Twenty-five sessions were completed over five to seven weeks. Pre, post, and follow-up measures included a battery of cognitive measures (three WM tests), a subjective memory scale, and a functional measure. Both intervention groups improved over time. Cogmed significantly outperformed Sham on Span Board and exceeded in subjective memory reports at follow-up as assessed by the Cognitive Failures Questionnaire (CFQ). The Cogmed group demonstrated better performance on the Functional Activities Questionnaire (FAQ), a measure of adjustment and far transfer, at follow-up. Both groups, especially Cogmed, enjoyed the intervention. Results suggest that WM was enhanced in both groups of older adults with MCI. Cogmed was better on one core WM measure and had higher ratings of satisfaction. The Sham condition declined on adjustment.

  15. Parallel External Memory Graph Algorithms

    DEFF Research Database (Denmark)

    Arge, Lars Allan; Goodrich, Michael T.; Sitchinava, Nodari

    2010-01-01

    In this paper, we study parallel I/O efficient graph algorithms in the Parallel External Memory (PEM) model, one o f the private-cache chip multiprocessor (CMP) models. We study the fundamental problem of list ranking which leads to efficient solutions to problems on trees, such as computing lowest...... an optimal speedup of ¿(P) in parallel I/O complexity and parallel computation time, compared to the single-processor external memory counterparts....

  16. Memory Modulation

    NARCIS (Netherlands)

    Roozendaal, Benno; McGaugh, James L.

    2011-01-01

    Our memories are not all created equally strong: Some experiences are well remembered while others are remembered poorly, if at all. Research on memory modulation investigates the neurobiological processes and systems that contribute to such differences in the strength of our memories. Extensive

  17. Assessment of Mental Status.

    Science.gov (United States)

    Finney, Glen R; Minagar, Alireza; Heilman, Kenneth M

    2016-02-01

    Assessing the mental status of patients with a neurobehavioral disorder is a critical element in the diagnosis and treatment of these patients. This assessment should always be performed after the patient's history it taken and a general physical as well as a neurologic examination is completed. The mental status examination commences with observing the patient's appearance and level of consciousness. The examiner should also pay attention to patient's social behavior, emotional state and mood. There are 3 major means of assessing a patient's mental status. One type attempts to determine if the patient is demented and the severity of the dementia as it pertains to their ability to perform activities of daily living as well as instrumental activities. A second type of assessment utilizes what may be termed as "screening tests" or "omnibus tests". These brief tests are performed independent of the patient's history and examination. The two most frequently used screening tests are the Mini-Mental Status Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The third means of assessing a patient's mental status is by using specific neuropsychological tests that focus on specific domains of cognition, such as frontal executive functions, attention, episodic verbal and visuospatial memory, declarative knowledge such as language (speech, reading and writing) and arithmetical, as well as visuospatial and perceptual abilities. These neurobehavioral, neuropsychiatric and neuropsychological assessments of patients with a cognitive decline and behavioral abnormalities should often be accompanied by laboratory tests, and neuroimaging that can help determine the underlying pathologic process so that effective therapeutic and management approaches can be provided. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. RAM-efficient external memory sorting

    DEFF Research Database (Denmark)

    Arge, Lars; Thorup, Mikkel

    2013-01-01

    In recent years a large number of problems have been considered in external memory models of computation, where the complexity measure is the number of blocks of data that are moved between slow external memory and fast internal memory (also called I/Os). In practice, however, internal memory time...... often dominates the total running time once I/O-efficiency has been obtained. In this paper we study algorithms for fundamental problems that are simultaneously I/O-efficient and internal memory efficient in the RAM model of computation....

  19. Effects of a Memory Training Program in Older People with Severe Memory Loss

    Science.gov (United States)

    Mateos, Pedro M.; Valentin, Alberto; González-Tablas, Maria del Mar; Espadas, Verónica; Vera, Juan L.; Jorge, Inmaculada García

    2016-01-01

    Strategies based memory training programs are widely used to enhance the cognitive abilities of the elderly. Participants in these training programs are usually people whose mental abilities remain intact. Occasionally, people with cognitive impairment also participate. The aim of this study was to test if memory training designed specifically for…

  20. Activating Attachments Reduces Memories of Traumatic Images.

    Directory of Open Access Journals (Sweden)

    Richard A Bryant

    Full Text Available Emotional memories, and especially intrusive memories, are a common feature of many psychological disorders, and are overconsolidated by stress. Attachment theory posits that activation of mental representations of attachment figures can reduce stress and boost coping. This study tested the proposition that attachment activation would reduce consolidation of emotional and intrusive memories. Sixty-seven undergraduate students viewed subliminal presentations of traumatic and neutral images, which were preceded by subliminal presentations of either attachment-related images or non-attachment-related images; free recall and intrusive memories were assessed two days later. Participants with low avoidant attachment tendencies who received the attachment primes recalled fewer memories and reported fewer intrusions than those who received the non-attachment primes. Unexpectedly, those with high anxious attachment tendencies reported fewer memories. These findings generally accord with attachment theory, and suggest that consolidation of emotional memories can be moderated by activation of attachment representations.

  1. Memory Dysfunction

    Science.gov (United States)

    Matthews, Brandy R.

    2015-01-01

    Purpose of Review: This article highlights the dissociable human memory systems of episodic, semantic, and procedural memory in the context of neurologic illnesses known to adversely affect specific neuroanatomic structures relevant to each memory system. Recent Findings: Advances in functional neuroimaging and refinement of neuropsychological and bedside assessment tools continue to support a model of multiple memory systems that are distinct yet complementary and to support the potential for one system to be engaged as a compensatory strategy when a counterpart system fails. Summary: Episodic memory, the ability to recall personal episodes, is the subtype of memory most often perceived as dysfunctional by patients and informants. Medial temporal lobe structures, especially the hippocampal formation and associated cortical and subcortical structures, are most often associated with episodic memory loss. Episodic memory dysfunction may present acutely, as in concussion; transiently, as in transient global amnesia (TGA); subacutely, as in thiamine deficiency; or chronically, as in Alzheimer disease. Semantic memory refers to acquired knowledge about the world. Anterior and inferior temporal lobe structures are most often associated with semantic memory loss. The semantic variant of primary progressive aphasia (svPPA) is the paradigmatic disorder resulting in predominant semantic memory dysfunction. Working memory, associated with frontal lobe function, is the active maintenance of information in the mind that can be potentially manipulated to complete goal-directed tasks. Procedural memory, the ability to learn skills that become automatic, involves the basal ganglia, cerebellum, and supplementary motor cortex. Parkinson disease and related disorders result in procedural memory deficits. Most memory concerns warrant bedside cognitive or neuropsychological evaluation and neuroimaging to assess for specific neuropathologies and guide treatment. PMID:26039844

  2. What Is Mental Health?

    Science.gov (United States)

    ... Myths and Facts Recovery Is Possible What Is Mental Health? Mental health includes our emotional, psychological, and social ... mental health problems and where to find help . Mental Health and Wellness Positive mental health allows people to: ...

  3. Activating attachment representations during memory retrieval modulates intrusive traumatic memories.

    Science.gov (United States)

    Bryant, Richard A; Chan, Iris

    2017-10-01

    Although priming mental representations of attachment security reduces arousal, research has not examined the effect of attachment on the retrieval of emotionally arousing memories. This study investigated the effect of priming attachment security on the retrieval of emotional memories. Seventy-five participants viewed negative and neutral images, and two days later received either an attachment prime or a control prime immediately prior to free recall of the images. Two days later, participants reported how frequently they experienced intrusions of the negative images. The attachment group had less distress, and reported fewer subsequent intrusions than the control group. Attachment style moderated these effects such that individuals with an avoidant attachment style were not impacted by the attachment prime. These findings suggest that priming attachment security decreases distress during memory reactivation, and this may reduce subsequent intrusive memories. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Declarative memory.

    Science.gov (United States)

    Riedel, Wim J; Blokland, Arjan

    2015-01-01

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

  5. Deciphering Neural Codes of Memory during Sleep

    Science.gov (United States)

    Chen, Zhe; Wilson, Matthew A.

    2017-01-01

    Memories of experiences are stored in the cerebral cortex. Sleep is critical for consolidating hippocampal memory of wake experiences into the neocortex. Understanding representations of neural codes of hippocampal-neocortical networks during sleep would reveal important circuit mechanisms on memory consolidation, and provide novel insights into memory and dreams. Although sleep-associated ensemble spike activity has been investigated, identifying the content of memory in sleep remains challenging. Here, we revisit important experimental findings on sleep-associated memory (i.e., neural activity patterns in sleep that reflect memory processing) and review computational approaches for analyzing sleep-associated neural codes (SANC). We focus on two analysis paradigms for sleep-associated memory, and propose a new unsupervised learning framework (“memory first, meaning later”) for unbiased assessment of SANC. PMID:28390699

  6. Avaliação da memória operacional fonológica e impulsividade de usuários de drogas atendidos em um Centro de Atenção Integrada à Saúde Mental Evaluation of phonological working memory and impulsivity of drugs users treated at an integrated care center for mental health

    Directory of Open Access Journals (Sweden)

    Luciana Lopes Silva Costa

    2012-06-01

    Full Text Available OBJETIVO: avaliar a memória operacional fonológica e relacionar com a impulsividade de pacientes em tratamento no Centro de Atenção Integrada à Saúde Mental. MÉTODO: 29 usuários: 21 do gênero masculino e 8 do feminino, usuários de substâncias psicoativas, com 37,9±10,5 anos de idade e 10,59±3,53 anos de escolaridade; e 30 voluntários: 19 do gênero masculino e 11 do feminino, com 32,4±11,9 anos de idade e 11,07±3,29 anos de escolaridade, sem histórico psiquiátrico ou de dependência química foram convocados à avaliação de: 1 memória operacional para palavras e pseudo-palavras; 2 impulsividade em seus fatores de segunda ordem (impulsividade atencional, motora e de não planejamento. RESULTADOS: o desempenho dos usuários de substâncias psicoativas na avaliação da memória em comparação ao grupo controle foi pior tanto no span auditivo de palavras e pseudo-palavras como também no número total de recordação de palavras e pseudo-palavras. Na avaliação da impulsividade, os usuários apresentaram escores elevados em contraposição aos sujeitos controle em todos os subtipos de impulsividade, inclusive no total. Na análise de correlação dos dados não foram encontradas relações entre os escores de impulsividade e memória. CONCLUSÃO: : este padrão de respostas indica comprometimento da memória operacional fonológica provavelmente independente do alto nível de impulsividade apresentado pelos usuários de drogas. Estas análises contribuem para propor estratégias de tratamento direcionadas às alterações detectadas.PURPOSE: to evaluate the phonological working memory abilities and check possible influences of impulsivity in patients starting treatment at the program for Alcohol and Drug users at CAISM. METHOD: 29 patients: 21 males and 8 females, drug users, 37.9±10.5 year old and with 10.59±3.53 years of schooling; and 30 volunteers: 19 males and 11 female, 32.4±11.9 year old and 11.07±3.29 years of

  7. Episodic Memory: A Comparative Approach

    Science.gov (United States)

    Martin-Ordas, Gema; Call, Josep

    2013-01-01

    Historically, episodic memory has been described as autonoetic, personally relevant, complex, context-rich, and allowing mental time travel. In contrast, semantic memory, which is theorized to be free of context and personal relevance, is noetic and consists of general knowledge of facts about the world. The field of comparative psychology has adopted this distinction in order to study episodic memory in non-human animals. Our aim in this article is not only to reflect on the concept of episodic memory and the experimental approaches used in comparative psychology to study this phenomenon, but also to provide a critical analysis of these paradigms. We conclude the article by providing new avenues for future research. PMID:23781179

  8. Self-reported wrist and finger symptoms associated with other physical/mental symptoms and use of computers/mobile phones.

    Science.gov (United States)

    Korpinen, Leena; Pääkkönen, Rauno; Gobba, Fabriziomaria

    2018-03-01

    Recently, computer, mobile phone and Internet use has increased. This study aimed to determine the possible relation between self-reported wrist and finger symptoms (aches, pain or numbness) and using computers/mobile phones, and to analyze how the symptoms are specifically associated with utilizing desktop computers, portable computers or mini-computers and mobile phones. A questionnaire was sent to 15,000 working-age Finns (age 18-65). Via a questionnaire, 723 persons reported wrist and finger symptoms often or more with use. Over 80% use mobile phones daily and less than 30% use desktop computers or the Internet daily at leisure, e.g., over 89.8% quite often or often experienced pain, numbness or aches in the neck, and 61.3% had aches in the hips and the lower back. Only 33.7% connected their symptoms to computer use. In the future, the development of new devices and Internet services should incorporate the ergonomics of the hands and wrists.

  9. Can Motivation Normalize Working Memory and Task Persistence in Children with Attention-Deficit/Hyperactivity Disorder? The Effects of Money and Computer-Gaming

    Science.gov (United States)

    Dovis, Sebastiaan; van der Oord, Saskia; Wiers, Reinout W.; Prins, Pier J. M.

    2012-01-01

    Visual-spatial "Working Memory" (WM) is the most impaired executive function in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Some suggest that deficits in executive functioning are caused by motivational deficits. However, there are no studies that investigate the effects of motivation on the visual-spatial WM of children with-…

  10. Can motivation normalize working memory and task persistence in children with attention-deficit/hyperactivity disorder? The effects of money and computer-gaming

    NARCIS (Netherlands)

    Dovis, S.; van der Oord, S.; Wiers, R.W.; Prins, P.J.M.

    2012-01-01

    Visual-spatial Working Memory (WM) is the most impaired executive function in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Some suggest that deficits in executive functioning are caused by motivational deficits. However, there are no studies that investigate the effects of

  11. Computational modelling of Ti50Pt50-xMx shape memory alloys (M: Ni, Ir or Pd and x = 6.25-43.75 at.%)

    CSIR Research Space (South Africa)

    Modiba, Rosinah M

    2017-09-01

    Full Text Available and medical stents (Wu and Schetky, 2000; Otsuka and Kakeshita, 2002; Van Humbeeck, 1999; Duerig, Pelton, and Stockel, 1999). A wide range of alloys are known to exhibit the shape memory effect, which occurs when a material returns to, or ‘remembers’, its...

  12. Computational modelling of Ti50Pt50-xMx shape memory alloys (M: Ni, Ir or Pd and x = 6.25-43.75 at.%)

    CSIR Research Space (South Africa)

    Modiba, Rosinah M

    2017-09-01

    Full Text Available The ab initio density functional theory approach was employed to study the effect of Ni, Ir or Pd addition to the TiPt shape memory alloy. The supercell approach in VASP was used to substitute Pt with 6.25, 18.75, 25.00, 31.25 and 43.75 at.% Ni, Ir...

  13. Learning, memory, and synesthesia.

    Science.gov (United States)

    Witthoft, Nathan; Winawer, Jonathan

    2013-03-01

    People with color-grapheme synesthesia experience color when viewing written letters or numerals, usually with a particular color evoked by each grapheme. Here, we report on data from 11 color-grapheme synesthetes who had startlingly similar color-grapheme pairings traceable to childhood toys containing colored letters. These are the first and only data to show learned synesthesia of this kind in more than a single individual. Whereas some researchers have focused on genetic and perceptual aspects of synesthesia, our results indicate that a complete explanation of synesthesia must also incorporate a central role for learning and memory. We argue that these two positions can be reconciled by thinking of synesthesia as the automatic retrieval of highly specific mnemonic associations, in which perceptual contents are brought to mind in a manner akin to mental imagery or the perceptual-reinstatement effects found in memory studies.

  14. Mental reversal of imagined melodies: a role for the posterior parietal cortex.

    Science.gov (United States)

    Zatorre, Robert J; Halpern, Andrea R; Bouffard, Marc

    2010-04-01

    Two fMRI experiments explored the neural substrates of a musical imagery task that required manipulation of the imagined sounds: temporal reversal of a melody. Musicians were presented with the first few notes of a familiar tune (Experiment 1) or its title (Experiment 2), followed by a string of notes that was either an exact or an inexact reversal. The task was to judge whether the second string was correct or not by mentally reversing all its notes, thus requiring both maintenance and manipulation of the represented string. Both experiments showed considerable activation of the superior parietal lobe (intraparietal sulcus) during the reversal process. Ventrolateral and dorsolateral frontal cortices were also activated, consistent with the memory load required during the task. We also found weaker evidence for some activation of right auditory cortex in both studies, congruent with results from previous simpler music imagery tasks. We interpret these results in the context of other mental transformation tasks, such as mental rotation in the visual domain, which are known to recruit the intraparietal sulcus region, and we propose that this region subserves general computations that require transformations of a sensory input. Mental imagery tasks may thus have both task or modality-specific components as well as components that supersede any specific codes and instead represent amodal mental manipulation.

  15. Short-term action potential memory and electrical restitution: A cellular computational study on the stability of cardiac repolarization under dynamic pacing.

    Directory of Open Access Journals (Sweden)

    Massimiliano Zaniboni

    Full Text Available Electrical restitution (ER is a major determinant of repolarization stability and, under fast pacing rate, it reveals memory properties of the cardiac action potential (AP, whose dynamics have never been fully elucidated, nor their ionic mechanisms. Previous studies have looked at ER mainly in terms of changes in AP duration (APD when the preceding diastolic interval (DI changes and described dynamic conditions where this relationship shows hysteresis which, in turn, has been proposed as a marker of short-term AP memory and repolarization stability. By means of numerical simulations of a non-propagated human ventricular AP, we show here that measuring ER as APD versus the preceding cycle length (CL provides additional information on repolarization dynamics which is not contained in the companion formulation. We focus particularly on fast pacing rate conditions with a beat-to-beat variable CL, where memory properties emerge from APD vs CL and not from APD vs DI and should thus be stored in APD and not in DI. We provide an ion-currents characterization of such conditions under periodic and random CL variability, and show that the memory stored in APD plays a stabilizing role on AP repolarization under pacing rate perturbations. The gating kinetics of L-type calcium current seems to be the main determinant of this safety mechanism. We also show that, at fast pacing rate and under otherwise identical pacing conditions, a periodically beat-to-beat changing CL is more effective than a random one in stabilizing repolarization. In summary, we propose a novel view of short-term AP memory, differentially stored between systole and diastole, which opens a number of methodological and theoretical implications for the understanding of arrhythmia development.

  16. Generalized memory associativity in a network model for the neuroses

    Science.gov (United States)

    Wedemann, Roseli S.; Donangelo, Raul; de Carvalho, Luís A. V.

    2009-03-01

    We review concepts introduced in earlier work, where a neural network mechanism describes some mental processes in neurotic pathology and psychoanalytic working-through, as associative memory functioning, according to the findings of Freud. We developed a complex network model, where modules corresponding to sensorial and symbolic memories interact, representing unconscious and conscious mental processes. The model illustrates Freud's idea that consciousness is related to symbolic and linguistic memory activity in the brain. We have introduced a generalization of the Boltzmann machine to model memory associativity. Model behavior is illustrated with simulations and some of its properties are analyzed with methods from statistical mechanics.

  17. Mental Byomdannelse

    DEFF Research Database (Denmark)

    Olsen, Tina Vestermann; Boye, Anne Mette; Borchmann, Inger Haarup

    Formålet med publikationen er at præsentere metoden "Mental byomdannelse". Metoden viser, hvordan man via midlertidig brug af grunde kan undersøge et steds potentialer, tage et område i brug tidligt i en byomdannelsesproces og derved bidrage til at opbygge en ny identitet for området. Mental...... byomdannelse går ud på at skabe bevidsthed om et byudviklingsområde overfor byens borgere, kommende beboere og fremtidige brugere af området allerede mens den fysiske omdannelse er i gang. I publikationen præsenteres en værktøjskasse, som giver redskaber og ideer til, hvordan man kan sætte en mental...... byomdannelsesproces i gang i byens rum. Publikationen udgør en afrapportering fra et støttet forsøgsprojekt hvor metoden ”Mental byomdannelse” er udviklet ved at afprøve ideerne om mental byomdannelse i to cases i Ålborg Kommune, hhv. i Østre Havn og Nibe by. Formålet med at anvende metoden i de to cases har været...

  18. Memory design

    DEFF Research Database (Denmark)

    Tanderup, Sisse

    by cultural forms, often specifically by the concept of memory in philosophy, sociology and psychology, while Danish design traditionally has been focusing on form and function with frequent references to the forms of nature. Alessi's motivation for investigating the concept of memory is that it adds......Mind and Matter - Nordik 2009 Conference for Art Historians Design Matters Contributed Memory design BACKGROUND My research concerns the use of memory categories in the designs by the companies Alessi and Georg Jensen. When Alessi's designers create their products, they are usually inspired...... a cultural dimension to the design objects, enabling the objects to make an identity-forming impact. Whether or not the concept of memory plays a significant role in Danish design has not yet been elucidated fully. TERMINOLOGY The concept of "memory design" refers to the idea that design carries...

  19. Disputed Memory

    DEFF Research Database (Denmark)

    , individual and political discourse and electronic social media. Analyzing memory disputes in various local, national and transnational contexts, the chapters demonstrate the political power and social impact of painful and disputed memories. The book brings new insights into current memory disputes...... in Central, Eastern and Southeastern Europe. It contributes to the understanding of processes of memory transmission and negotiation across borders and cultures in Europe, emphasizing the interconnectedness of memory with emotions, mediation and politics....... century in the region. Written by an international group of scholars from a diversity of disciplines, the chapters approach memory disputes in methodologically innovative ways, studying representations and negotiations of disputed pasts in different media, including monuments, museum exhibitions...

  20. Computers, the Human Mind, and My In-Laws' House.

    Science.gov (United States)

    Esque, Timm J.

    1996-01-01

    Discussion of human memory, computer memory, and the storage of information focuses on a metaphor that can account for memory without storage and can set the stage for systemic research around a more comprehensive, understandable theory. (Author/LRW)