WorldWideScience

Sample records for memory mental time

  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. 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.

  3. 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…

  4. 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.

  5. 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 ...

  6. 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)

  7. 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.

  8. Time for memory

    DEFF Research Database (Denmark)

    Murakami, Kyoko

    2012-01-01

    This article is a continuous dialogue on memory triggered by Brockmeier’s (2010) article. I drift away from the conventionalization of the archive as a spatial metaphor for memory in order to consider the greater possibility of “time” for conceptualizing memory. The concept of time is central...... in terms of autobiographical memory. The second category of time is discussed, drawing on Augustine and Bergson amongst others. Bergson’s notion of duration has been considered as a promising concept for a better understanding of autobiographical memory. Psychological phenomena such as autobiographical...... memory should embrace not only spatial dimension, but also a temporal dimension, in which a constant flow of irreversible time, where multiplicity, momentarily, dynamic stability and becoming and emergence of novelty can be observed....

  9. 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 ...

  10. 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.

  11. Time Series with Long Memory

    OpenAIRE

    西埜, 晴久

    2004-01-01

    The paper investigates an application of long-memory processes to economic time series. We show properties of long-memory processes, which are motivated to model a long-memory phenomenon in economic time series. An FARIMA model is described as an example of long-memory model in statistical terms. The paper explains basic limit theorems and estimation methods for long-memory processes in order to apply long-memory models to economic time series.

  12. 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

  13. 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.

  14. 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.

  15. 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...

  16. Priming the Mental Time Line

    Science.gov (United States)

    Di Bono, Maria Grazia; Casarotti, Marco; Priftis, Konstantinos; Gava, Lucia; Umilta, Carlo; Zorzi, Marco

    2012-01-01

    Growing experimental evidence suggests that temporal events are represented on a mental time line, spatially oriented from left to right. Support for the spatial representation of time comes mostly from studies that have used spatially organized responses. Moreover, many of these studies did not avoid possible confounds attributable to target…

  17. 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.

  18. Wandering tales: evolutionary origins of mental time travel and language

    Science.gov (United States)

    Corballis, Michael C.

    2013-01-01

    A central component of mind wandering is mental time travel, the calling to mind of remembered past events and of imagined future ones. Mental time travel may also be critical to the evolution of language, which enables us to communicate about the non-present, sharing memories, plans, and ideas. Mental time travel is indexed in humans by hippocampal activity, and studies also suggest that the hippocampus in rats is active when the animals replay or pre play activity in a spatial environment, such as a maze. Mental time travel may have ancient origins, contrary to the view that it is unique to humans. Since mental time travel is also thought to underlie language, these findings suggest that language evolved gradually from pre-existing cognitive capacities, contrary to the view of Chomsky and others that language and symbolic thought emerged abruptly, in a single step, within the past 100,000 years. PMID:23908641

  19. Wandering Tales: Evolutionary origins of mental time travel and language

    Directory of Open Access Journals (Sweden)

    Michael Charles Corballis

    2013-07-01

    Full Text Available A central component of mind wandering is mental time travel, the calling to mind of remembered past events and of imagined future ones. Mental time travel may also be critical to the evolution of language, which enables us to communicate about the nonpresent, sharing memories, plans, and ideas. Mental time travel is indexed in humans by hippocampal activity, and studies also suggest that the hippocampus in rats is active when the animals replay or pre play activity in a spatial environment, such as a maze. Mental time travel may have ancient origins, contrary to the view that it is unique to humans. Since mental time travel is also thought to underlie language, these findings suggest that language evolved gradually from pre-existing cognitive capacities, contrary to the view of Chomsky and others that language and symbolic thought emerged abruptly, in a single step, within the past 100,000 years.

  20. Mental time travel and the shaping of language.

    Science.gov (United States)

    Corballis, Michael C

    2009-01-01

    Episodic memory can be regarded as part of a more general system, unique to humans, for mental time travel, and the construction of future episodes. This allows more detailed planning than is afforded by the more general mechanisms of instinct, learning, and semantic memory. To be useful, episodic memory need not provide a complete or even a faithful record of past events, and may even be part of a process whereby we construct fictional accounts. The properties of language are aptly designed for the communication and sharing of episodes, and for the telling of stories; these properties include symbolic representation of the elements of real-world events, time markers, and combinatorial rules. Language and mental time travel probably co-evolved during the Pleistocene, when brain size increased dramatically.

  1. A real-time multichannel memory controller and optimal mapping of memory clients to memory channels

    NARCIS (Netherlands)

    Gomony, M.D.; Akesson, K.B.; Goossens, K.G.W.

    2015-01-01

    Ever-increasing demands for main memory bandwidth and memory speed/power tradeoff led to the introduction of memories with multiple memory channels, such as Wide IO DRAM. Efficient utilization of a multichannel memory as a shared resource in multiprocessor real-time systems depends on mapping of the

  2. Parallel effects of memory set activation and searchon timing and working memory capacity

    Directory of Open Access Journals (Sweden)

    Richard eSchweickert

    2014-07-01

    Full Text Available Accurately estimating a time interval is required in everyday activities such as driving or cooking. Estimating time is relatively easy, provided a person attends to it. But a brief shift of attention to another task usually interferes with timing. Most processes carried out concurrently with timing interfere with it. Curiously, some do not. Literature on a few processes suggests a general proposition, the Timing and Complex-Span Hypothesis: A process interferes with concurrent timing if and only if process performance is related to complex span. Complex-span is the number of items correctly recalled in order, when each item presented for study is followed by a brief activity. Literature on task switching, visual search, memory search, word generation and mental time travel supports the hypothesis. Previous work found that another process, activation of a memory set in long term memory, is not related to complex-span. If the Timing and Complex-Span Hypothesis is true, activation should not interfere with concurrent timing in dual-task conditions. We tested such activation in single-task memory search task conditions and in dual-task conditions where memory search was executed with concurrent timing. In Experiment 1, activating a memory set increased reaction time, with no significant effect on time production. In Experiment 2, set size and memory set activation were manipulated. Activation and set size had a puzzling interaction for time productions, perhaps due to difficult conditions, leading us to use a related but easier task in Experiment 3. In Experiment 3 increasing set size lengthened time production, but memory activation had no significant effect. Results here and in previous literature on the whole support the Timing and Complex-Span Hypotheses. Results also support a sequential organization of activation and search of memory. This organization predicts activation and set size have additive effects on reaction time and multiplicative

  3. Parallel effects of memory set activation and search on timing and working memory capacity.

    Science.gov (United States)

    Schweickert, Richard; Fortin, Claudette; Xi, Zhuangzhuang; Viau-Quesnel, Charles

    2014-01-01

    Accurately estimating a time interval is required in everyday activities such as driving or cooking. Estimating time is relatively easy, provided a person attends to it. But a brief shift of attention to another task usually interferes with timing. Most processes carried out concurrently with timing interfere with it. Curiously, some do not. Literature on a few processes suggests a general proposition, the Timing and Complex-Span Hypothesis: A process interferes with concurrent timing if and only if process performance is related to complex span. Complex-span is the number of items correctly recalled in order, when each item presented for study is followed by a brief activity. Literature on task switching, visual search, memory search, word generation and mental time travel supports the hypothesis. Previous work found that another process, activation of a memory set in long term memory, is not related to complex-span. If the Timing and Complex-Span Hypothesis is true, activation should not interfere with concurrent timing in dual-task conditions. We tested such activation in single-task memory search task conditions and in dual-task conditions where memory search was executed with concurrent timing. In Experiment 1, activating a memory set increased reaction time, with no significant effect on time production. In Experiment 2, set size and memory set activation were manipulated. Activation and set size had a puzzling interaction for time productions, perhaps due to difficult conditions, leading us to use a related but easier task in Experiment 3. In Experiment 3 increasing set size lengthened time production, but memory activation had no significant effect. Results here and in previous literature on the whole support the Timing and Complex-Span Hypotheses. Results also support a sequential organization of activation and search of memory. This organization predicts activation and set size have additive effects on reaction time and multiplicative effects on percent

  4. 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.

  5. 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.

  6. 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.

  7. [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.

  8. Learned Interval Time Facilitates Associate Memory Retrieval

    Science.gov (United States)

    van de Ven, Vincent; Kochs, Sarah; Smulders, Fren; De Weerd, Peter

    2017-01-01

    The extent to which time is represented in memory remains underinvestigated. We designed a time paired associate task (TPAT) in which participants implicitly learned cue-time-target associations between cue-target pairs and specific cue-target intervals. During subsequent memory testing, participants showed increased accuracy of identifying…

  9. Hold it! memory affects attentional dwell time

    OpenAIRE

    Parks, Emily L.; Hopfinger, Joseph B.

    2008-01-01

    The allocation of attention, including the initial orienting and the subsequent dwell time, is affected by several bottom-up and top-down factors. How item memory affects these processes, however, remains unclear. Here, we investigated whether item memory affects attentional dwell time by using a modified version of the attentional blink (AB) paradigm. Across four experiments, our results revealed that the AB was significantly affected by memory status (novel vs. old), but critically, this ef...

  10. 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

  11. 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.

  12. Multiple memory systems, multiple time points: how science can inform treatment to control the expression of unwanted emotional memories.

    Science.gov (United States)

    Visser, Renée M; Lau-Zhu, Alex; Henson, Richard N; Holmes, Emily A

    2018-03-19

    Memories that have strong emotions associated with them are particularly resilient to forgetting. This is not necessarily problematic, however some aspects of memory can be. In particular, the involuntary expression of those memories, e.g. intrusive memories after trauma, are core to certain psychological disorders. Since the beginning of this century, research using animal models shows that it is possible to change the underlying memory, for example by interfering with its consolidation or reconsolidation. While the idea of targeting maladaptive memories is promising for the treatment of stress and anxiety disorders, a direct application of the procedures used in non-human animals to humans in clinical settings is not straightforward. In translational research, more attention needs to be paid to specifying what aspect of memory (i) can be modified and (ii) should be modified. This requires a clear conceptualization of what aspect of memory is being targeted, and how different memory expressions may map onto clinical symptoms. Furthermore, memory processes are dynamic, so procedural details concerning timing are crucial when implementing a treatment and when assessing its effectiveness. To target emotional memory in its full complexity, including its malleability, science cannot rely on a single method, species or paradigm. Rather, a constructive dialogue is needed between multiple levels of research, all the way 'from mice to mental health'.This article is part of a discussion meeting issue 'Of mice and mental health: facilitating dialogue between basic and clinical neuroscientists'. © 2018 The Authors.

  13. Retrieving fear memories, as time goes by…

    Science.gov (United States)

    Do Monte, Fabricio H.; Quirk, Gregory J.; Li, Bo; Penzo, Mario A.

    2016-01-01

    Fear conditioning researches have led to a comprehensive picture of the neuronal circuit underlying the formation of fear memories. In contrast, knowledge about the retrieval of fear memories is much more limited. This disparity may stem from the fact that fear memories are not rigid, but reorganize over time. To bring clarity and raise awareness on the time-dependent dynamics of retrieval circuits, we review current evidence on the neuronal circuitry participating in fear memory retrieval at both early and late time points after conditioning. We focus on the temporal recruitment of the paraventricular nucleus of the thalamus, and its BDNFergic efferents to the central nucleus of the amygdala, for the retrieval and maintenance of fear memories. Finally, we speculate as to why retrieval circuits change across time, and the functional benefits of recruiting structures such as the paraventricular nucleus into the retrieval circuit. PMID:27217148

  14. The Renewal Center: Time, Experience, Memory

    OpenAIRE

    Tennant, Mark

    2005-01-01

    Time, Experience, Memory Through experience we are conscious of time. Through time, our experiences become memories, influencing both conscious and unconscious thought. It is through our five senses; touch, sight, hearing, smell and taste, that these experiences are gathered. Humans are also born with inherent knowledge that our species has collected from generation to generation. This inherent knowledge, also called the collective unconscious, has a direct effect on the way we perce...

  15. 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.

  16. Spike-timing theory of working memory.

    Directory of Open Access Journals (Sweden)

    Botond Szatmáry

    Full Text Available Working memory (WM is the part of the brain's memory system that provides temporary storage and manipulation of information necessary for cognition. Although WM has limited capacity at any given time, it has vast memory content in the sense that it acts on the brain's nearly infinite repertoire of lifetime long-term memories. Using simulations, we show that large memory content and WM functionality emerge spontaneously if we take the spike-timing nature of neuronal processing into account. Here, memories are represented by extensively overlapping groups of neurons that exhibit stereotypical time-locked spatiotemporal spike-timing patterns, called polychronous patterns; and synapses forming such polychronous neuronal groups (PNGs are subject to associative synaptic plasticity in the form of both long-term and short-term spike-timing dependent plasticity. While long-term potentiation is essential in PNG formation, we show how short-term plasticity can temporarily strengthen the synapses of selected PNGs and lead to an increase in the spontaneous reactivation rate of these PNGs. This increased reactivation rate, consistent with in vivo recordings during WM tasks, results in high interspike interval variability and irregular, yet systematically changing, elevated firing rate profiles within the neurons of the selected PNGs. Additionally, our theory explains the relationship between such slowly changing firing rates and precisely timed spikes, and it reveals a novel relationship between WM and the perception of time on the order of seconds.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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…

  2. Traces of times past : Representations of temporal intervals in memory

    NARCIS (Netherlands)

    Taatgen, Niels; van Rijn, Hedderik

    2011-01-01

    Theories of time perception typically assume that some sort of memory represents time intervals. This memory component is typically underdeveloped in theories of time perception. Following earlier work that suggested that representations of different time intervals contaminate each other (Grondin,

  3. 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.

  4. Time and cognitive load in working memory.

    OpenAIRE

    Barrouillet , Pierre; Bernardin , Sophie; Portrat , Sophie; Vergauwe , Evie; Camos , Valérie

    2007-01-01

    International audience; According to the time-based resource-sharing model (P. Barrouillet, S. Bernardin, & V. Camos, 2004), the cognitive load a given task involves is a function of the proportion of time during which it captures attention, thus impeding other attention-demanding processes. Accordingly, the present study demonstrates that the disruptive effect on concurrent maintenance of memory retrievals and response selections increases with their duration. Moreover, the effect on recall ...

  5. 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.

  6. DETECTING GRAVITATIONAL WAVE MEMORY WITH PULSAR TIMING

    International Nuclear Information System (INIS)

    Cordes, J. M.; Jenet, F. A.

    2012-01-01

    We compare the detectability of gravitational bursts passing through the solar system with those passing near each millisecond pulsar in an N-pulsar timing array. The sensitivity to Earth-passing bursts can exploit the correlation expected in pulse arrival times while pulsar-passing bursts, though uncorrelated between objects, provide an N-fold increase in overall time baseline that can compensate for the lower sensitivity. Bursts with memory from mergers of supermassive black holes produce step functions in apparent spin frequency that are the easiest to detect in pulsar timing. We show that the burst rate and amplitude distribution, while strongly dependent on inadequately known cosmological evolution, may favor detection in the pulsar terms rather than the Earth timing perturbations. Any contamination of timing data by red spin noise makes burst detection more difficult because both signals grow with the length of the time data span T. Furthermore, the different bursts that could appear in one or more data sets of length T ≈ 10 yr also affect the detectability of the gravitational wave stochastic background that, like spin noise, has a red power spectrum. A burst with memory is a worthwhile target in the timing of multiple pulsars in a globular cluster because it should produce a correlated signal with a time delay of less than about 10 years in some cases.

  7. Detecting Gravitational Wave Memory with Pulsar Timing

    Science.gov (United States)

    Cordes, J. M.; Jenet, F. A.

    2012-06-01

    We compare the detectability of gravitational bursts passing through the solar system with those passing near each millisecond pulsar in an N-pulsar timing array. The sensitivity to Earth-passing bursts can exploit the correlation expected in pulse arrival times while pulsar-passing bursts, though uncorrelated between objects, provide an N-fold increase in overall time baseline that can compensate for the lower sensitivity. Bursts with memory from mergers of supermassive black holes produce step functions in apparent spin frequency that are the easiest to detect in pulsar timing. We show that the burst rate and amplitude distribution, while strongly dependent on inadequately known cosmological evolution, may favor detection in the pulsar terms rather than the Earth timing perturbations. Any contamination of timing data by red spin noise makes burst detection more difficult because both signals grow with the length of the time data span T. Furthermore, the different bursts that could appear in one or more data sets of length T ≈ 10 yr also affect the detectability of the gravitational wave stochastic background that, like spin noise, has a red power spectrum. A burst with memory is a worthwhile target in the timing of multiple pulsars in a globular cluster because it should produce a correlated signal with a time delay of less than about 10 years in some cases.

  8. Prospective and retrospective time perception are related to mental time travel: evidence from Alzheimer's disease.

    Science.gov (United States)

    El Haj, Mohamad; Moroni, Christine; Samson, Séverine; Fasotti, Luciano; Allain, Philippe

    2013-10-01

    Unlike prospective time perception paradigms, in which participants are aware that they have to estimate forthcoming time, little is known about retrospective time perception in normal aging and Alzheimer's disease (AD). Our paper addresses this shortcoming by comparing prospective and retrospective time estimation in younger adults, older adults, and AD patients. In four prospective tasks (lasting 30s, 60s, 90s, or 120s) participants were asked to read a series of numbers and to provide a verbal estimation of the reading time. In four other retrospective tasks, they were not informed about time judgment until they were asked to provide a verbal estimation of four elapsed time intervals (lasting 30s, 60s, 90s, or 120s). AD participants gave shorter verbal time estimations than older adults and younger participants did, suggesting that time is perceived to pass quickly in these patients. For all participants, the duration of the retrospective tasks was underestimated as compared to the prospective tasks and both estimations were shorter than the real time interval. Prospective time estimation was further correlated with mental time travel, as measured with the Remember/Know paradigm. Mental time travel was even higher correlated with retrospective time estimation. Our findings shed light on the relationship between time perception and the ability to mentally project oneself into time, two skills contributing to human memory functioning. Finally, time perception deficits, as observed in AD patients, can be interpreted in terms of dramatic changes occurring in frontal lobes and hippocampus. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Perceived Time as a Measure of Mental Workload

    DEFF Research Database (Denmark)

    Hertzum, Morten; Holmegaard, Kristin Due

    2013-01-01

    The mental workload imposed by systems is important to their operation and usability. Consequently, researchers and practitioners need reliable, valid, and easy-to-administer methods for measuring mental workload. The ratio of perceived time to clock time appears to be such a method, yet mental...... is a performance-related rather than task-related dimension of mental workload. We find a higher perceived time ratio for timed than untimed tasks. According to subjective workload ratings and pupil-diameter measurements the timed tasks impose higher mental workload. This finding contradicts the prospective...... paradigm, which asserts that perceived time decreases with increasing mental workload. We also find a higher perceived time ratio for solved than unsolved tasks, while subjective workload ratings indicate lower mental workload for the solved tasks. This finding shows that the relationship between...

  10. 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)

  11. A Time-predictable Memory Network-on-Chip

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Chong, David VH; Puffitsch, Wolfgang

    2014-01-01

    To derive safe bounds on worst-case execution times (WCETs), all components of a computer system need to be time-predictable: the processor pipeline, the caches, the memory controller, and memory arbitration on a multicore processor. This paper presents a solution for time-predictable memory...... arbitration and access for chip-multiprocessors. The memory network-on-chip is organized as a tree with time-division multiplexing (TDM) of accesses to the shared memory. The TDM based arbitration completely decouples processor cores and allows WCET analysis of the memory accesses on individual cores without...

  12. 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.

  13. 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…

  14. The Development of Time-Based Prospective Memory in Childhood: The Role of Working Memory Updating

    Science.gov (United States)

    Voigt, Babett; Mahy, Caitlin E. V.; Ellis, Judi; Schnitzspahn, Katharina; Krause, Ivonne; Altgassen, Mareike; Kliegel, Matthias

    2014-01-01

    This large-scale study examined the development of time-based prospective memory (PM) across childhood and the roles that working memory updating and time monitoring play in driving age effects in PM performance. One hundred and ninety-seven children aged 5 to 14 years completed a time-based PM task where working memory updating load was…

  15. Time and interference: Effects on working memory.

    Science.gov (United States)

    Botto, Marta; Palladino, Paola

    2016-05-01

    This study tested predictions from the time-based resource-sharing (TBRS) model with a classical verbal working memory (WM) task, where target and non-target information interfere strongly with each other. Different predictions can be formulated according to the dominant perspectives (TBRS and interference hypothesis) on the role of inhibitory control in WM task performance. Here, we aimed to trace the activation of irrelevant information, examining priming effects in a lexical decision task immediately following WM recall. Results indicate the roles of both time and interference constraints in determining task performance. In particular, the role of time available seemed crucial at the highest WM loads (i.e., 3 and 4 memoranda). These were also associated with a higher activation of no-longer-relevant information but, in this case, independently from time available for processing. © 2015 The British Psychological Society.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Time-dependent effects of cardiovascular exercise on memory

    DEFF Research Database (Denmark)

    Roig, Marc; Thomas, Richard; Mang, Cameron S

    2016-01-01

    We present new evidence supporting the hypothesis that the effects of cardiovascular exercise on memory can be regulated in a time-dependent manner. When the exercise stimulus is temporally coupled with specific phases of the memory formation process, a single bout of cardiovascular exercise may...... be sufficient to improve memory. SUMMARY: The timing of exercise in relation to the information to be remembered is critical to maximize the effects of acute cardiovascular exercise on memory....

  1. Disturbance of time orientation, attention, and verbal memory in amnesic patients with confabulation.

    Science.gov (United States)

    Shingaki, Honoka; Park, Paeksoon; Ueda, Keita; Murai, Toshiya; Tsukiura, Takashi

    2016-01-01

    Confabulation is often observed in amnesic patients after brain damage. However, evidence regarding the relationship between confabulation and other neuropsychological functions is scarce. In addition, previous studies have proposed two possibilities of the relationship between confabulation and false memory, in which patients with confabulation are likely to retrieve false memories, or confabulations are relatively independent of false memories. The present study investigated how confabulation is related to various cognitive functions, including orientation, attention, frontal lobe function, memory, and mental status, and to false memories, as assessed by the Deese-Roediger-Mcdermott (DRM) paradigm. Patients with organic amnesia participated, and confabulations were evaluated using the Confabulation Battery. Amnestic patients were classified into two groups: confabulating (CP) and nonconfabulating patients (NCP). The CP group was significantly impaired in time orientation, attention, and verbal memory, compared to the NCP group and age-matched healthy controls (HC). Results of the DRM paradigm revealed no significant difference in false memory retrieval induced by critical lures across CP, NCP, and HC groups. Confabulating responses in organic amnesia could be in part induced by disturbance of time consciousness and attention control in severe impairment of verbal memories, and confabulation and false memory could be modulated by different cognitive systems.

  2. Insect olfactory memory in time and space.

    Science.gov (United States)

    Liu, Xu; Davis, Ronald L

    2006-12-01

    Recent studies using functional optical imaging have revealed that cellular memory traces form in different areas of the insect brain after olfactory classical conditioning. These traces are revealed as increased calcium signals or synaptic release from defined neurons, and include a short-lived trace that forms immediately after conditioning in antennal lobe projection neurons, an early trace in dopaminergic neurons, and a medium-term trace in dorsal paired medial neurons. New molecular genetic tools have revealed that for normal behavioral memory performance, synaptic transmission from the mushroom body neurons is required only during retrieval, whereas synaptic transmission from dopaminergic neurons is required at the time of acquisition and synaptic transmission from dorsal paired medial neurons is required during the consolidation period. Such experimental results are helping to identify the types of neurons that participate in olfactory learning and when their participation is required. Olfactory learning often occurs alongside crossmodal interactions of sensory information from other modalities. Recent studies have revealed complex interactions between the olfactory and the visual senses that can occur during olfactory learning, including the facilitation of learning about subthreshold olfactory stimuli due to training with concurrent visual stimuli.

  3. Time course of effects of emotion on item memory and source memory for Chinese words.

    Science.gov (United States)

    Wang, Bo; Fu, Xiaolan

    2011-05-01

    Although many studies have investigated the effect of emotion on memory, it is unclear whether the effect of emotion extends to all aspects of an event. In addition, it is poorly understood how effects of emotion on item memory and source memory change over time. This study examined the time course of effects of emotion on item memory and source memory. Participants learned intentionally a list of neutral, positive, and negative Chinese words, which were presented twice, and then took test of free recall, followed by recognition and source memory tests, at one of eight delayed points of time. The main findings are (within the time frame of 2 weeks): (1) Negative emotion enhances free recall, whereas there is only a trend that positive emotion enhances free recall. In addition, negative and positive emotions have different points of time at which their effects on free recall reach the greatest magnitude. (2) Negative emotion reduces recognition, whereas positive emotion has no effect on recognition. (3) Neither positive nor negative emotion has any effect on source memory. The above findings indicate that effect of emotion does not necessarily extend to all aspects of an event and that valence is a critical modulating factor in effect of emotion on item memory. Furthermore, emotion does not affect the time course of item memory and source memory, at least with a time frame of 2 weeks. This study has implications for establishing the theoretical model regarding the effect of emotion on memory. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Episodic autobiographical memories over the course of time: cognitive, neuropsychological and neuroimaging findings.

    Science.gov (United States)

    Piolino, Pascale; Desgranges, Béatrice; Eustache, Francis

    2009-09-01

    The critical attributes of episodic memory are self, autonoetic consciousness and subjectively sensed time. The aim of this paper is to present a theoretical overview of our already published researches into the nature of episodic memory over the course of time. We have developed a new method of assessing autobiographical memory (TEMPau task), which is specially designed to measure these specific aspects, based on the sense of re-experiencing events from across the entire lifespan. Based on our findings of cognitive, neuropsychological and neuroimaging studies, new insights into episodic autobiographical memories are presented, focusing on the effects of age of the subjects interacting with time interval in healthy subjects and lesioned patients. The multifaceted and complex nature of episodic memory is emphasized and it is suggested that mental time travel through subjective time, which allows individuals to re-experience specific past events through a feeling of self-awareness, is the last feature of autobiographical memory to become fully operational in development and the first feature to go in aging and most amnesias. Our findings highlight the critical role of frontotemporal areas in constructive autobiographical memory processes, and especially hippocampus, in re-experiencing episodic details from the recent or more distant past.

  5. Quantum Physics and Mental Health Counseling: The Time Is...!

    Science.gov (United States)

    Gerstein, Lawrence H.; Bennett, Matt

    1999-01-01

    Introduces a new framework of mental health counseling based on quantum physics. The framework stresses systemic thinking and intervention, interdependence, and the importance of adopting a novel perspective about time, space, reality, and change. This framework has the potential of modifying mental health counseling practice and training. Offers…

  6. Scaling properties in time-varying networks with memory

    Science.gov (United States)

    Kim, Hyewon; Ha, Meesoon; Jeong, Hawoong

    2015-12-01

    The formation of network structure is mainly influenced by an individual node's activity and its memory, where activity can usually be interpreted as the individual inherent property and memory can be represented by the interaction strength between nodes. In our study, we define the activity through the appearance pattern in the time-aggregated network representation, and quantify the memory through the contact pattern of empirical temporal networks. To address the role of activity and memory in epidemics on time-varying networks, we propose temporal-pattern coarsening of activity-driven growing networks with memory. In particular, we focus on the relation between time-scale coarsening and spreading dynamics in the context of dynamic scaling and finite-size scaling. Finally, we discuss the universality issue of spreading dynamics on time-varying networks for various memory-causality tests.

  7. The Development of Time-Based Prospective Memory in Childhood: The Role of Working Memory Updating

    NARCIS (Netherlands)

    Voigt, B.; Mahy, C.E.V.; Ellis, J.; Schnitzspahn, K.M.; Krause, I.; Altgassen, A.M.; Kliegel, M.

    2014-01-01

    This large-scale study examined the development of time-based prospective memory (PM) across childhood and the roles that working memory updating and time monitoring play in driving age effects in PM performance. One hundred and ninety-seven children aged 5 to 14 years completed a time-based PM task

  8. 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.

  9. Time-Frequency Domain Memory and Processing

    National Research Council Canada - National Science Library

    Huestis, David

    2002-01-01

    This report summarizes the results of a 3-year program of research on the physics and technology needed to develop high-performance optical memory and optical processing systems based on the concept...

  10. 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.

  11. 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.

  12. 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.

  13. Stack Memory Implementation and Analysis of Timing Constraint, Power and Memory using FPGA

    DEFF Research Database (Denmark)

    Thind, Vandana; Pandey, Nisha; Pandey, Bishwajeet

    2017-01-01

    real-time output, so that source used to realize the project is not wasted and get an energy efficient design. However, Stack memory is an approach in which information is entered and deleted from the stack memory segment in the pattern of last in first out mechanism. There are several ways...... of implementation of stack memory algorithm but virtex4 and virtex7 low voltage were considered to be the most efficient platforms for its operation. The developed system is energy efficient as the algorim ensures less memory utilization, less power consumption and short time for signal travel.......Abstract— in this work of analysis, stack memory algorithm is implemented on a number of FPGA platforms like virtex4, virtex5, virtex6, virtex6 low power and virtex7 low voltage and very detailed observations/investigations were made about timing constraint, memory and power dissipation. The main...

  14. 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)

  15. Memory Efficient Data Structures for Explicit Verification of Timed Systems

    DEFF Research Database (Denmark)

    Taankvist, Jakob Haahr; Srba, Jiri; Larsen, Kim Guldstrand

    2014-01-01

    Timed analysis of real-time systems can be performed using continuous (symbolic) or discrete (explicit) techniques. The explicit state-space exploration can be considerably faster for models with moderately small constants, however, at the expense of high memory consumption. In the setting of timed......-arc Petri nets, we explore new data structures for lowering the used memory: PTries for efficient storing of configurations and time darts for semi-symbolic description of the state-space. Both methods are implemented as a part of the tool TAPAAL and the experiments document at least one order of magnitude...... of memory savings while preserving comparable verification times....

  16. The meandering mind: vection and mental time travel.

    Directory of Open Access Journals (Sweden)

    Lynden K Miles

    Full Text Available BACKGROUND: The ability to travel mentally through time sets humans apart from many other species, yet little is known about this core cognitive capacity. In particular, what shapes the passage of the mind's journey through time? Guided by the viewpoint that higher cognitive activity can have a sensory-motor grounding, we explored the possibility that mental time travel is influenced by apparent movement through space. METHODOLOGY/PRINCIPAL FINDINGS: Participants performed a mundane vigilance task, during which they were expected to daydream, while viewing a display that elicited an illusion of self-motion (i.e., vection. Afterwards, the contents of their mind wandering experiences were probed. The results revealed that the direction of apparent motion influenced the temporal focus of mental time travel. While backward vection prompted thinking about the past, forward vection triggered a preponderance of future-oriented thoughts. CONCLUSIONS/SIGNIFICANCE: Consistent with recent evidence that traveling mentally through time entails associated movements in space, the current results demonstrate the converse relationship-apparent movement through space influenced the temporal locus of mental activity. Together, these findings corroborate the viewpoint that mental time travel may be grounded in the embodiment of spatiotemporal information in a bidirectional manner.

  17. 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.

  18. 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

  19. 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…

  20. Mental Time Travel into the Past and the Future in Healthy Aged Adults: An fMRI Study

    Science.gov (United States)

    Viard, Armelle; Chetelat, Gael; Lebreton, Karine; Desgranges, Beatrice; Landeau, Brigitte; de La Sayette, Vincent; Eustache, Francis; Piolino, Pascale

    2011-01-01

    Remembering the past and envisioning the future rely on episodic memory which enables mental time travel. Studies in young adults indicate that past and future thinking share common cognitive and neural underpinnings. No imaging data is yet available in healthy aged subjects. Using fMRI, we scanned older subjects while they remembered personal…

  1. 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.

  2. The hippocampus, time and working memory.

    Science.gov (United States)

    Rawlins, J N; Tsaltas, E

    1983-12-01

    Rats were trained on a discrete trial working memory leverpress alternation task, following hippocampal lesions (HC), cortical control lesions (CC) or sham operations (SO). Each trial consisted of a forced information response, for which a randomly selected lever was presented followed by a free choice stage, when both levers were presented. The rats were rewarded for pressing the lever which had not been presented at the information stage. When the information response was not rewarded, all rats learnt the task equally well at IRIs of up to 12.75 sec. When the information response was rewarded, the HC rats showed impaired choice accuracy. The extent of this impairment depended on the IRI, being greatest at long IRIs, and least at short ones. Varying the number of leverpresses required to complete the information response affected choice accuracy equivalently in all groups: all rats chose significantly less accurately when only one leverpress was required than when ten leverpresses were required. There was no interaction between the lesion treatments and the information response requirements. It was concluded that both the length of the IRI and the occurrence of events during the IRI determine the extent of the hippocampal lesion-induced performance deficit in working memory tasks. It is proposed that hippocampal damage disrupts an intermediate-term, high-capacity memory buffer, but leaves both a residual short-term memory system and the long-term retention of associations unaffected. This proposal leads to the prediction that reference memory tasks should also be affected by hippocampal lesions when a delay is introduced between making a response and being rewarded for doing so.

  3. Neural Networks for Time Perception and Working Memory

    Science.gov (United States)

    Üstün, Sertaç; Kale, Emre H.; Çiçek, Metehan

    2017-01-01

    Time is an important concept which determines most human behaviors, however questions remain about how time is perceived and which areas of the brain are responsible for time perception. The aim of this study was to evaluate the relationship between time perception and working memory in healthy adults. Functional magnetic resonance imaging (fMRI) was used during the application of a visual paradigm. In all of the conditions, the participants were presented with a moving black rectangle on a gray screen. The rectangle was obstructed by a black bar for a time period and then reappeared again. During different conditions, participants (n = 15, eight male) responded according to the instructions they were given, including details about time and the working memory or dual task requirements. The results showed activations in right dorsolateral prefrontal and right intraparietal cortical networks, together with the anterior cingulate cortex (ACC), anterior insula and basal ganglia (BG) during time perception. On the other hand, working memory engaged the left prefrontal cortex, ACC, left superior parietal cortex, BG and cerebellum activity. Both time perception and working memory were related to a strong peristriate cortical activity. On the other hand, the interaction of time and memory showed activity in the intraparietal sulcus (IPS) and posterior cingulate cortex (PCC). These results support a distributed neural network based model for time perception and that the intraparietal and posterior cingulate areas might play a role in the interface of memory and timing. PMID:28286475

  4. The time course of working memory effects on visual attention differs depending on memory type

    NARCIS (Netherlands)

    Dombrowe, I.; Olivers, C.N.L.; Donk, M.

    2010-01-01

    Previous work has generated inconsistent results with regard to what extent working memory (WM) content guides visual attention. Some studies found effects of easy to verbalize stimuli, whereas others only found an influence of visual memory content. To resolve this, we compared the time courses of

  5. 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.

  6. Quantifying memory in complex physiological time-series.

    Science.gov (United States)

    Shirazi, Amir H; Raoufy, Mohammad R; Ebadi, Haleh; De Rui, Michele; Schiff, Sami; Mazloom, Roham; Hajizadeh, Sohrab; Gharibzadeh, Shahriar; Dehpour, Ahmad R; Amodio, Piero; Jafari, G Reza; Montagnese, Sara; Mani, Ali R

    2013-01-01

    In a time-series, memory is a statistical feature that lasts for a period of time and distinguishes the time-series from a random, or memory-less, process. In the present study, the concept of "memory length" was used to define the time period, or scale over which rare events within a physiological time-series do not appear randomly. The method is based on inverse statistical analysis and provides empiric evidence that rare fluctuations in cardio-respiratory time-series are 'forgotten' quickly in healthy subjects while the memory for such events is significantly prolonged in pathological conditions such as asthma (respiratory time-series) and liver cirrhosis (heart-beat time-series). The memory length was significantly higher in patients with uncontrolled asthma compared to healthy volunteers. Likewise, it was significantly higher in patients with decompensated cirrhosis compared to those with compensated cirrhosis and healthy volunteers. We also observed that the cardio-respiratory system has simple low order dynamics and short memory around its average, and high order dynamics around rare fluctuations.

  7. Forecasting long memory time series under a break in persistence

    DEFF Research Database (Denmark)

    Heinen, Florian; Sibbertsen, Philipp; Kruse, Robinson

    We consider the problem of forecasting time series with long memory when the memory parameter is subject to a structural break. By means of a large-scale Monte Carlo study we show that ignoring such a change in persistence leads to substantially reduced forecasting precision. The strength...... of this effect depends on whether the memory parameter is increasing or decreasing over time. A comparison of six forecasting strategies allows us to conclude that pre-testing for a change in persistence is highly recommendable in our setting. In addition we provide an empirical example which underlines...

  8. Time, not sleep, unbinds contexts from item memory.

    Directory of Open Access Journals (Sweden)

    Roy Cox

    Full Text Available Contextual cues are known to benefit memory retrieval, but whether and how sleep affects this context effect remains unresolved. We manipulated contextual congruence during memory retrieval in human volunteers across 12 h and 24 h intervals beginning with either sleep or wakefulness. Our data suggest that whereas contextual cues lose their potency with time, sleep does not modulate this process. Furthermore, our results are consistent with the idea that sleep's beneficial effect on memory retention depends on the amount of waking time that has passed between encoding and sleep onset. The findings are discussed in the framework of competitive consolidation theory.

  9. 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.

  10. Sleep Deprivation and Time-Based Prospective Memory.

    Science.gov (United States)

    Esposito, Maria José; Occhionero, Miranda; Cicogna, PierCarla

    2015-11-01

    To evaluate the effect of sleep deprivation on time-based prospective memory performance, that is, realizing delayed intentions at an appropriate time in the future (e.g., to take a medicine in 30 minutes). Between-subjects experimental design. The experimental group underwent 24 h of total sleep deprivation, and the control group had a regular sleep-wake cycle. Participants were tested at 08:00. Laboratory. Fifty healthy young adults (mean age 22 ± 2.1, 31 female). 24 h of total sleep deprivation. Participants were monitored by wrist actigraphy for 3 days before the experimental session. The following cognitive tasks were administered: one time-based prospective memory task and 3 reasoning tasks as ongoing activity. Objective and subjective vigilance was assessed by the psychomotor vigilance task and a visual analog scale, respectively. To measure the time-based prospective memory task we assessed compliance and clock checking behavior (time monitoring). Sleep deprivation negatively affected time-based prospective memory compliance (P sleep deprivation on human behavior, particularly the ability to perform an intended action after a few minutes. Sleep deprivation strongly compromises time-based prospective memory compliance but does not affect time check frequency. Sleep deprivation may impair the mechanism that allows the integration of information related to time monitoring with the prospective intention. © 2015 Associated Professional Sleep Societies, LLC.

  11. The Role of Perspective in Mental Time Travel.

    Science.gov (United States)

    Ansuini, Caterina; Cavallo, Andrea; Pia, Lorenzo; Becchio, Cristina

    2016-01-01

    Recent years have seen accumulating evidence for the proposition that people process time by mapping it onto a linear spatial representation and automatically "project" themselves on an imagined mental time line. Here, we ask whether people can adopt the temporal perspective of another person when travelling through time. To elucidate similarities and differences between time travelling from one's own perspective or from the perspective of another person, we asked participants to mentally project themselves or someone else (i.e., a coexperimenter) to different time points. Three basic properties of mental time travel were manipulated: temporal location (i.e., where in time the travel originates: past, present, and future), motion direction (either backwards or forwards), and temporal duration (i.e., the distance to travel: one, three, or five years). We found that time travels originating in the present lasted longer in the self- than in the other-perspective. Moreover, for self-perspective, but not for other-perspective, time was differently scaled depending on where in time the travel originated. In contrast, when considering the direction and the duration of time travelling, no dissimilarities between the self- and the other-perspective emerged. These results suggest that self- and other-projection, despite some differences, share important similarities in structure.

  12. Visuospatial asymmetries and emotional valence influence mental time travel.

    Science.gov (United States)

    Thomas, Nicole A; Takarangi, Melanie K T

    2018-06-01

    Spatial information is tightly intertwined with temporal and valence-based information. Namely, "past" is represented on the left, and "future" on the right, along a horizontal mental timeline. Similarly, right is associated with positive, whereas left is negative. We developed a novel task to examine the effects of emotional valence and temporal distance on mental representations of time. We compared positivity biases, where positive events are positioned closer to now, and right hemisphere emotion biases, where negative events are positioned to the left. When the entire life span was used, a positivity bias emerged; positive events were closer to now. When timeline length was reduced, positivity and right hemisphere emotion biases were consistent for past events. In contrast, positive and negative events were equidistant from now in the future condition, suggesting positivity and right hemisphere emotion biases opposed one another, leading events to be positioned at a similar distance. We then reversed the timeline by moving past to the right and future to the left. Positivity biases in the past condition were eliminated, and negative events were placed slightly closer to now in the future condition. We conclude that an underlying left-to-right mental representation of time is necessary for positivity biases to emerge for past events; however, our mental representations of future events are inconsistent with positivity biases. These findings point to an important difference in the way in which we represent the past and the future on our mental timeline. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  13. 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.

  14. Being (un)moved by mental time travel

    NARCIS (Netherlands)

    Stins, J.F.; Habets, L.; Jongeling, R.; Canal Bruland, R.

    Mental imagery of events in the past or future, and of unpleasant or pleasant events, has been found to lead to spontaneous backward/forward bodily motions. Both time and emotion are represented along a spatial continuum, and activation of these representations seems to be simulated in spontaneous

  15. 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.…

  16. Soil moisture memory at sub-monthly time scales

    Science.gov (United States)

    Mccoll, K. A.; Entekhabi, D.

    2017-12-01

    For soil moisture-climate feedbacks to occur, the soil moisture storage must have `memory' of past atmospheric anomalies. Quantifying soil moisture memory is, therefore, essential for mapping and characterizing land-atmosphere interactions globally. Most previous studies estimate soil moisture memory using metrics based on the autocorrelation function of the soil moisture time series (e.g., the e-folding autocorrelation time scale). This approach was first justified by Delworth and Manabe (1988) on the assumption that monthly soil moisture time series can be modelled as red noise. While this is a reasonable model for monthly soil moisture averages, at sub-monthly scales, the model is insufficient due to the highly non-Gaussian behavior of the precipitation forcing. Recent studies have shown that significant soil moisture-climate feedbacks appear to occur at sub-monthly time scales. Therefore, alternative metrics are required for defining and estimating soil moisture memory at these shorter time scales. In this study, we introduce metrics, based on the positive and negative increments of the soil moisture time series, that can be used to estimate soil moisture memory at sub-monthly time scales. The positive increments metric corresponds to a rapid drainage time scale. The negative increments metric represents a slower drying time scale that is most relevant to the study of land-atmosphere interactions. We show that autocorrelation-based metrics mix the two time scales, confounding physical interpretation. The new metrics are used to estimate soil moisture memory at sub-monthly scales from in-situ and satellite observations of soil moisture. Reference: Delworth, Thomas L., and Syukuro Manabe. "The Influence of Potential Evaporation on the Variabilities of Simulated Soil Wetness and Climate." Journal of Climate 1, no. 5 (May 1, 1988): 523-47. doi:10.1175/1520-0442(1988)0012.0.CO;2.

  17. The Perception of Time: Influences on Physical and Mental Health

    Directory of Open Access Journals (Sweden)

    Cristián Rodrigo Oyanadel Véliz

    2011-01-01

    Full Text Available With a broad understanding of time perception, the dimensions positive past, negative past, fatalistic present, hedonistic present and future were grouped in profiles to assess relations with physical and mental health. Using a quasi-experimental design, 50 subjects matched for age and sex completed the Zimbardo Time Perspective Inventory and the SF-36, with 3 measures of time estimation. Pearson correlations and ANOVA showed significant relationships between dimensions, physical and mental health, and estimation. Three profiles were obtained, with the balanced one (BTP having the best health indicators. These results support the idea that it is good to have a balanced profile that implies a positive attitude to the past, future orientation, and enjoying pleasant experiences. Also, health is influenced by time estimation

  18. Time and Cognitive Load in Working Memory

    Science.gov (United States)

    Barrouillet, Pierre; Bernardin, Sophie; Portrat, Sophie; Vergauwe, Evie; Camos, Valerie

    2007-01-01

    According to the time-based resource-sharing model (P. Barrouillet, S. Bernardin, & V. Camos, 2004), the cognitive load a given task involves is a function of the proportion of time during which it captures attention, thus impeding other attention-demanding processes. Accordingly, the present study demonstrates that the disruptive effect on…

  19. 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.

  20. Mental time travel: a case for evolutionary continuity.

    Science.gov (United States)

    Corballis, Michael C

    2013-01-01

    In humans, hippocampal activity responds to the imagining of past or future events. In rats, hippocampal activity is tied to particular locations in a maze, occurs after the animal has been in the maze, and sometimes corresponds to locations the animal did not actually visit. This suggests that mental time travel has neurophysiological underpinnings that go far back in evolution, and may not be, as some (including myself) have claimed, unique to humans. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Migration and common mental disorder: an improvement in mental health over time?

    Science.gov (United States)

    Butler, Margaret; Warfa, Nasir; Khatib, Yasmin; Bhui, Kamaldeep

    2015-02-01

    Global migration is reaching record high levels and UK migrant groups comprise an increasing proportion of the total population. The migratory process causes stress that can affect mental health. There is limited consistent empirical evidence of a longitudinal nature to explain the association between migration and mental health. This review aims to examine the evidence of a relationship between migration and common mental disorder (CMD) amongst migrants over time. A comprehensive search of medical and psychiatric databases for global quantitative empirical studies investigating incidence of CMD amongst adult migrants from 1975 to July 2012 was conducted. Declines in rates of CMD amongst migrants over time were reported by two thirds of the 18 studies reviewed, less than one third of which were statistically significant. On the contrary, three studies showed an increased rate of CMD, one statistically significant. Individual psychological resources, social support, the acculturation process, cultural variations and time since relocation are identified as statistically significant protective factors against the development of CMD amongst migrants. New enlightening points include the significant impact of varying patterns of psychological distress, of which negative is the most adverse for CMD. Migration is an extremely complex process. Further clarification is needed to gain deeper understanding of the relationship between migration and CMD to address contradictions in the literature and health inequalities amongst migrants.

  2. 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

  3. 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.

  4. Finite-Time Stability for Fractional-Order Bidirectional Associative Memory Neural Networks with Time Delays

    International Nuclear Information System (INIS)

    Xu Chang-Jin; Li Pei-Luan; Pang Yi-Cheng

    2017-01-01

    This paper is concerned with fractional-order bidirectional associative memory (BAM) neural networks with time delays. Applying Laplace transform, the generalized Gronwall inequality and estimates of Mittag–Leffler functions, some sufficient conditions which ensure the finite-time stability of fractional-order bidirectional associative memory neural networks with time delays are obtained. Two examples with their simulations are given to illustrate the theoretical findings. Our results are new and complement previously known results. (paper)

  5. The Endurance of Children's Working Memory: A Recall Time Analysis

    Science.gov (United States)

    Towse, John N.; Hitch, Graham J.; Hamilton, Z.; Pirrie, Sarah

    2008-01-01

    We analyze the timing of recall as a source of information about children's performance in complex working memory tasks. A group of 8-year-olds performed a traditional operation span task in which sequence length increased across trials and an operation period task in which processing requirements were extended across trials of constant sequence…

  6. The cholinergic system, circadian rhythmicity, and time memory

    NARCIS (Netherlands)

    Hut, R. A.; Van der Zee, E. A.

    2011-01-01

    This review provides an overview of the interaction between the mammalian cholinergic system and circadian system, and its possible role in time memory. Several studies made clear that circadian (daily) fluctuations in acetylcholine (ACh) release, cholinergic enzyme activity and cholinergic receptor

  7. Modality Differences in Timing and Temporal Memory throughout the Lifespan

    Science.gov (United States)

    Lustig, Cindy; Meck, Warren H.

    2011-01-01

    The perception of time is heavily influenced by attention and memory, both of which change over the lifespan. In the current study, children (8 yrs), young adults (18-25 yrs), and older adults (60-75 yrs) were tested on a duration bisection procedure using 3 and 6-s auditory and visual signals as anchor durations. During test, participants were…

  8. Picture Memory Improves with Longer On Time and Off Time

    Science.gov (United States)

    Tversky, Barbara; Sherman, Tracy

    1975-01-01

    Both recognition and recall of pictures improve as picture presentation time increases and as time between picture increases. This experiment was compared with an earlier one by Shaffer and Shiffrin (1972). (Editor/RK)

  9. Time domain optical memories using rare earth ions

    International Nuclear Information System (INIS)

    Sellars, M.J.; Dyke, T.; Pryde, G.J.; Manson, N.B.

    1998-01-01

    Full text: Rare earth doped crystals are the chosen materials for the next generation of optical memories where the process of spectral holeburning can be employed to provide an extra dimension of frequency or time to spatial dimensions and with certain rare earth ions increases of the order of 10 7 in storage capacity can be achieved over conventional optical memories. Time domain techniques are preferred over frequency domain techniques and are now well developed. In these techniques arbitrary pulse sequences are stored in the material and read out at some later time with a single read pulse using a stimulated photon echo process. Long pulse sequences will enable more data to be stored but necessitates the use of materials with long dephasing times (corresponding to narrow spectral lines) and it is this characteristic of rare earth systems that makes them the preferred material for the new time domain optical memories. The storage time can range from hours to days but in a practical device will require refreshing or re-enforcing and this puts special requirements on the stability of the laser used for storing the information. The storage process itself can also be weak and more reliable storage can be achieved by recording the data several times with the same pulse sequence. For this to be successful the laser must be at held at a constant frequency and be stable in phase over the entire duration of the pulse sequence. The procedure of reinforcing the data sequence has been proposed before and attempted without attention to the laser frequency stability. However, if the laser is not stable although some data bits will be reinforced or increased in size others will be decreased or even erased. Indeed the reliability of the memory is degraded by the introducing the rewrite process. For our work we have developed a laser with the excellent stability and able to demonstrate reproducible reinforcement of the data sequence. Thus with the rewrite sequence we are able to

  10. Brain system for mental orientation in space, time, and person.

    Science.gov (United States)

    Peer, Michael; Salomon, Roy; Goldberg, Ilan; Blanke, Olaf; Arzy, Shahar

    2015-09-01

    Orientation is a fundamental mental function that processes the relations between the behaving self to space (places), time (events), and person (people). Behavioral and neuroimaging studies have hinted at interrelations between processing of these three domains. To unravel the neurocognitive basis of orientation, we used high-resolution 7T functional MRI as 16 subjects compared their subjective distance to different places, events, or people. Analysis at the individual-subject level revealed cortical activation related to orientation in space, time, and person in a precisely localized set of structures in the precuneus, inferior parietal, and medial frontal cortex. Comparison of orientation domains revealed a consistent order of cortical activity inside the precuneus and inferior parietal lobes, with space orientation activating posterior regions, followed anteriorly by person and then time. Core regions at the precuneus and inferior parietal lobe were activated for multiple orientation domains, suggesting also common processing for orientation across domains. The medial prefrontal cortex showed a posterior activation for time and anterior for person. Finally, the default-mode network, identified in a separate resting-state scan, was active for all orientation domains and overlapped mostly with person-orientation regions. These findings suggest that mental orientation in space, time, and person is managed by a specific brain system with a highly ordered internal organization, closely related to the default-mode network.

  11. Topological order and memory time in marginally-self-correcting quantum memory

    Science.gov (United States)

    Siva, Karthik; Yoshida, Beni

    2017-03-01

    We examine two proposals for marginally-self-correcting quantum memory: the cubic code by Haah and the welded code by Michnicki. In particular, we prove explicitly that they are absent of topological order above zero temperature, as their Gibbs ensembles can be prepared via a short-depth quantum circuit from classical ensembles. Our proof technique naturally gives rise to the notion of free energy associated with excitations. Further, we develop a framework for an ergodic decomposition of Davies generators in CSS codes which enables formal reduction to simpler classical memory problems. We then show that memory time in the welded code is doubly exponential in inverse temperature via the Peierls argument. These results introduce further connections between thermal topological order and self-correction from the viewpoint of free energy and quantum circuit depth.

  12. The effect of time perspectives on mental health information processing and help-seeking attitudes and intentions in younger versus older adults.

    Science.gov (United States)

    Erickson, Julie; Mackenzie, Corey S; Menec, Verena H; Bailis, Daniel S

    2017-03-01

    Socioemotional selectivity theory posits that changes in time perspective over the lifespan are associated with distinct goals and motivations. Time perspectives and their associated socioemotional motivations have been shown to influence information processing and memory, such that motivation-consistent information is more likely to be remembered and evaluated more positively. The aim of this study was to examine the effect of motivation-consistent mental health information on memory for and evaluations of this information, as well as help-seeking attitudes and intentions to seek mental health services. We randomly assigned an Internet-based sample of 160 younger (18-25) and 175 older (60-89) adults to read a mental health information pamphlet that emphasized time perspectives and motivations relevant to either young adulthood (future-focused) or late adulthood (present-focused). Participants completed measures assessing their time perspective, memory for and subjective evaluation of the pamphlet, and help-seeking attitudes and intentions. The time perspective manipulation had no effect on memory for pamphlet information or help-seeking attitudes and intentions. There was, however, a significant interaction between time perspective and pamphlet version on the rated liking of the pamphlet. Although motivation-consistent information only affected perceptions of that information for present-focused (mostly older) individuals, this finding has important implications for enhancing older adults' mental health literacy.

  13. 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.

  14. Time perception and psychopathology: Influence of time perspective on quality of life of severe mental illness.

    Science.gov (United States)

    Oyanadel, Cristián; Buela-Casal, Gualberto

    2014-01-01

    The study of time perception and mental illness has given priority to time estimation over time perspective. Considering Zimbardo’s theory on five dimensions of time perspective, and balanced time perspective profile, this study has aimed to compare people with severe mental illness (SMI) and healthy people, with measurements of time perspective and time estimation and to assess whether the time perspective profile influences the quality of life in people with SMI. Using a quasi-experimental design, a clinical group (n=167) corresponding to four samples of severe mental disorders (major depression, bipolar disorder, schizophrenia and personality disorders) and healthy people (n=167) were compared in their performance regarding time perspective and time estimation. After, the clinical sample was grouped according to their deviation from the balanced time perspective profile (DBTP) and negative profile (DNTP). These groups were evaluated with health measures and time estimation tasks. Through the ANOVA, it can be seen that the time perspective profile affects health measurements. There are significant differences between the clinical sample and controls regarding time perspective and time estimation. Within the group of patients, it was observed that those who were closer to the BTP profile had better physical health, and less hopelessness (ptime perspective in the assessment, treatment and quality of life of people with SMI.

  15. 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....

  16. 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.

  17. When Time Flies: How Abstract and Concrete Mental Construal Affect the Perception of Time

    Science.gov (United States)

    Hansen, Jochim; Trope, Yaacov

    2013-01-01

    Time is experienced as passing more quickly the more changes happen in a situation. The present research tested the idea that time perception depends on the level of construal of the situation. Building on previous research showing that concrete rather than abstract mental construal causes people to perceive more variations in a given situation,…

  18. Memory for time and place contributes to enhanced confidence in memories for emotional events

    Science.gov (United States)

    Rimmele, Ulrike; Davachi, Lila; Phelps, Elizabeth A.

    2012-01-01

    Emotion strengthens the subjective sense of remembering. However, these confidently remembered emotional memories have not been found be more accurate for some types of contextual details. We investigated whether the subjective sense of recollecting negative stimuli is coupled with enhanced memory accuracy for three specific types of central contextual details using the remember/know paradigm and confidence ratings. Our results indicate that the subjective sense of remembering is indeed coupled with better recollection of spatial location and temporal context. In contrast, we found a double-dissociation between the subjective sense of remembering and memory accuracy for colored dots placed in the conceptual center of negative and neutral scenes. These findings show that the enhanced subjective recollective experience for negative stimuli reliably indicates objective recollection for spatial location and temporal context, but not for other types of details, whereas for neutral stimuli, the subjective sense of remembering is coupled with all the types of details assessed. Translating this finding to flashbulb memories, we found that, over time, more participants correctly remembered the location where they learned about the terrorist attacks on 9/11 than any other canonical feature. Likewise participants’ confidence was higher in their memory for location vs. other canonical features. These findings indicate that the strong recollective experience of a negative event corresponds to an accurate memory for some kinds of contextual details, but not other kinds. This discrepancy provides further evidence that the subjective sense of remembering negative events is driven by a different mechanism than the subjective sense of remembering neutral events. PMID:22642353

  19. Long-time tails of correlation and memory functions

    Science.gov (United States)

    Sawada, Isao

    2002-11-01

    We review the generalized Langevin equation, which is a transformation and reformulation of equation of motion, from the two viewpoints: the projection operator method developed by Mori and the recurrence relations method developed by Lee. The fluctuating forces acting on the Bloch electrons’ current are clarified the strongly colored quantum fluctuations with the spontaneous interband transitions leading to a long-time tail of 1/ t for the envelope of the memory function. The velocity autocorrelation functions in the coupled harmonic oscillator on the Bethe lattice have a long-time tail of 1/t t. The oscillation and the form of decay found in correlation functions affect transport coefficients given by the integrated intensity up to infinity. We also study the force-force correlation functions often used as an approximation to the memory function.

  20. Functional mental capacity, treatment as usual and time: magnitude of change in secure hospital patients with major mental illness.

    LENUS (Irish Health Repository)

    Dornan, Julieanne

    2015-01-01

    Decision making ability can change with time, depending on mental or physical health. Little is known about the factors that determine this change and the relationship of capacity to time. As a pilot for studies using functional mental capacities as an outcome measure, we sought to quantify this relationship measuring change over time using competence assessment tools, and rating scales for symptoms and global function.

  1. 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…

  2. Memory controllers for real-time embedded systems predictable and composable real-time systems

    CERN Document Server

    Akesson, Benny

    2012-01-01

      Verification of real-time requirements in systems-on-chip becomes more complex as more applications are integrated. Predictable and composable systems can manage the increasing complexity using formal verification and simulation.  This book explains the concepts of predictability and composability and shows how to apply them to the design and analysis of a memory controller, which is a key component in any real-time system. This book is generally intended for readers interested in Systems-on-Chips with real-time applications.   It is especially well-suited for readers looking to use SDRAM memories in systems with hard or firm real-time requirements. There is a strong focus on real-time concepts, such as predictability and composability, as well as a brief discussion about memory controller architectures for high-performance computing. Readers will learn step-by-step how to go from an unpredictable SDRAM memory, offering highly variable bandwidth and latency, to a predictable and composable shared memory...

  3. Time manages interference in visual short-term memory.

    Science.gov (United States)

    Smith, Amy V; McKeown, Denis; Bunce, David

    2017-09-01

    Emerging evidence suggests that age-related declines in memory may reflect a failure in pattern separation, a process that is believed to reduce the encoding overlap between similar stimulus representations during memory encoding. Indeed, behavioural pattern separation may be indexed by a visual continuous recognition task in which items are presented in sequence and observers report for each whether it is novel, previously viewed (old), or whether it shares features with a previously viewed item (similar). In comparison to young adults, older adults show a decreased pattern separation when the number of items between "old" and "similar" items is increased. Yet the mechanisms of forgetting underpinning this type of recognition task are yet to be explored in a cognitively homogenous group, with careful control over the parameters of the task, including elapsing time (a critical variable in models of forgetting). By extending the inter-item intervals, number of intervening items and overall decay interval, we observed in a young adult sample (N = 35, M age  = 19.56 years) that the critical factor governing performance was inter-item interval. We argue that tasks using behavioural continuous recognition to index pattern separation in immediate memory will benefit from generous inter-item spacing, offering protection from inter-item interference.

  4. 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.

  5. The impact of perceived self-efficacy on mental time travel and social problem solving.

    Science.gov (United States)

    Brown, Adam D; Dorfman, Michelle L; Marmar, Charles R; Bryant, Richard A

    2012-03-01

    Current models of autobiographical memory suggest that self-identity guides autobiographical memory retrieval. Further, the capacity to recall the past and imagine one's self in the future (mental time travel) can influence social problem solving. We examined whether manipulating self-identity, through an induction task in which students were led to believe they possessed high or low self-efficacy, impacted episodic specificity and content of retrieved and imagined events, as well as social problem solving. Compared to individuals in the low self efficacy group, individuals in the high self efficacy group generated past and future events with greater (a) specificity, (b) positive words, and (c) self-efficacious statements, and also performed better on social problem solving indices. A lack of episodic detail for future events predicted poorer performance on social problem solving tasks. Strategies that increase perceived self-efficacy may help individuals to selectively construct a past and future that aids in negotiating social problems. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. When Delays Improve Memory: Stabilizing Memory in Children May Require Time

    OpenAIRE

    Darby, Kevin P.; Sloutsky, Vladimir M.

    2015-01-01

    Memory is critical for learning, cognition and cognitive development. Recent work has suggested that preschool-aged children are vulnerable to catastrophic levels of memory interference, in which new learning dramatically attenuates memory for previously acquired knowledge. Work reported here investigates the effects of consolidation on children’s memory by introducing a 48- hours-long delay between learning and testing. In Experiment 1, the delay improved children’s memory and eliminated int...

  7. Faster decline of pitch memory over time in congenital amusia.

    Science.gov (United States)

    Williamson, Victoria J; McDonald, Claire; Deutsch, Diana; Griffiths, Timothy D; Stewart, Lauren

    2010-04-26

    Congenital amusia (amusia, hereafter) is a developmental disorder that impacts negatively on the perception of music. Psychophysical testing suggests that individuals with amusia have above average thresholds for detection of pitch change and pitch direction discrimination; however, a low-level auditory perceptual problem cannot completely explain the disorder, since discrimination of melodies is also impaired when the constituent intervals are suprathreshold for perception. The aim of the present study was to test pitch memory as a function of (a) time and (b) tonal interference, in order to determine whether pitch traces are inherently weaker in amusic individuals. Memory for the pitch of single tones was compared using two versions of a paradigm developed by Deutsch (1970a). In both tasks, participants compared the pitch of a standard (S) versus a comparison (C) tone. In the time task, the S and C tones were presented, separated in time by 0, 1, 5, 10, and 15 s (blocked presentation). In the interference task, the S and C tones were presented with a fixed time interval (5 s) but with a variable number of irrelevant tones in between 0, 2, 4, 6, and 8 tones (blocked presentation). In the time task, control performance remained high for all time intervals, but amusics showed a performance decrement over time. In the interference task, controls and amusics showed a similar performance decrement with increasing number of irrelevant tones. Overall, the results suggest that the pitch representations of amusic individuals are less stable and more prone to decay than those of matched non-amusic individuals.

  8. Time to rethink the neural mechanisms of learning and memory.

    Science.gov (United States)

    Gallistel, Charles R; Balsam, Peter D

    2014-02-01

    Most studies in the neurobiology of learning assume that the underlying learning process is a pairing - dependent change in synaptic strength that requires repeated experience of events presented in close temporal contiguity. However, much learning is rapid and does not depend on temporal contiguity, which has never been precisely defined. These points are well illustrated by studies showing that the temporal relations between events are rapidly learned- even over long delays- and that this knowledge governs the form and timing of behavior. The speed with which anticipatory responses emerge in conditioning paradigms is determined by the information that cues provide about the timing of rewards. The challenge for understanding the neurobiology of learning is to understand the mechanisms in the nervous system that encode information from even a single experience, the nature of the memory mechanisms that can encode quantities such as time, and how the brain can flexibly perform computations based on this information. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Temporal Dissociation of Neocortical and Hippocampal Contributions to Mental Time Travel Using Intracranial Recordings in Humans.

    Science.gov (United States)

    Schurr, Roey; Nitzan, Mor; Eliahou, Ruth; Spinelli, Laurent; Seeck, Margitta; Blanke, Olaf; Arzy, Shahar

    2018-01-01

    In mental time travel (MTT) one is "traveling" back-and-forth in time, remembering, and imagining events. Despite intensive research regarding memory processes in the hippocampus, it was only recently shown that the hippocampus plays an essential role in encoding the temporal order of events remembered, and therefore plays an important role in MTT. Does it also encode the temporal relations of these events to the remembering self? We asked patients undergoing pre-surgical evaluation with depth electrodes penetrating the temporal lobes bilaterally toward the hippocampus to project themselves in time to a past, future, or present time-point, and then make judgments regarding various events. Classification analysis of intracranial evoked potentials revealed clear temporal dissociation in the left hemisphere between lateral-temporal electrodes, activated at ~100-300 ms, and hippocampal electrodes, activated at ~400-600 ms. This dissociation may suggest a division of labor in the temporal lobe during self-projection in time, hinting toward the different roles of the lateral-temporal cortex and the hippocampus in MTT and the temporal organization of the related events with respect to the experiencing self.

  10. Temporal Dissociation of Neocortical and Hippocampal Contributions to Mental Time Travel Using Intracranial Recordings in Humans

    Directory of Open Access Journals (Sweden)

    Roey Schurr

    2018-02-01

    Full Text Available In mental time travel (MTT one is “traveling” back-and-forth in time, remembering, and imagining events. Despite intensive research regarding memory processes in the hippocampus, it was only recently shown that the hippocampus plays an essential role in encoding the temporal order of events remembered, and therefore plays an important role in MTT. Does it also encode the temporal relations of these events to the remembering self? We asked patients undergoing pre-surgical evaluation with depth electrodes penetrating the temporal lobes bilaterally toward the hippocampus to project themselves in time to a past, future, or present time-point, and then make judgments regarding various events. Classification analysis of intracranial evoked potentials revealed clear temporal dissociation in the left hemisphere between lateral-temporal electrodes, activated at ~100–300 ms, and hippocampal electrodes, activated at ~400–600 ms. This dissociation may suggest a division of labor in the temporal lobe during self-projection in time, hinting toward the different roles of the lateral-temporal cortex and the hippocampus in MTT and the temporal organization of the related events with respect to the experiencing self.

  11. Episodic Autobiographical Memories over the Course of Time: Cognitive, Neuropsychological and Neuroimaging Findings

    Science.gov (United States)

    Piolino, Pascale; Desgranges, Beatrice; Eustache, Francis

    2009-01-01

    The critical attributes of episodic memory are self, autonoetic consciousness and subjectively sensed time. The aim of this paper is to present a theoretical overview of our already published researches into the nature of episodic memory over the course of time. We have developed a new method of assessing "autobiographical" memory (TEMPau task),…

  12. 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.

  13. Frontal brain activation during a working memory task: a time-domain fNIRS study

    Science.gov (United States)

    Molteni, E.; Baselli, G.; Bianchi, A. M.; Caffini, M.; Contini, D.; Spinelli, L.; Torricelli, A.; Cerutti, S.; Cubeddu, R.

    2009-02-01

    We evaluated frontal brain activation during a working memory task with graded levels of difficulty in a group of 19 healthy subjects, by means of time-resolved fNIRS technique. Brain activation was computed, and was then separated into a "block-related" and a "tonic" components. Load-related increases of blood oxygenation were studied for the four different levels of task difficulty. Generalized Linear Models were applied to the data in order to explore the metabolic processes occurring during the mental effort and, possibly, their involvement in short term memorization. Results attest the presence of a persistent attentional-related metabolic activity, superimposed to a task-related mnemonic contribution. Moreover, a systemic component probably deriving from the extra-cerebral capillary bed was detected.

  14. [Processing acoustically presented time intervals of seconds duration: an expression of the phonological loop of the working memory?].

    Science.gov (United States)

    Grube, D

    1996-01-01

    Working memory has been proposed to contribute to the processing of time, rhythm and music; the question which component of working memory is involved is under discussion. The present study tests the hypothesis that the phonological loop component (Baddeley, 1986) is involved in the processing of auditorily presented time intervals of a few seconds' duration. Typical effects well known with short-term retention of verbal material could be replicated with short-term retention of temporal intervals: The immediate reproduction of time intervals was impaired under conditions of background music and articulatory suppression. Neither the accuracy nor the speed of responses in a (non-phonological) mental rotation task were diminished under these conditions. Processing of auditorily presented time intervals seems to be constrained by the capacity of the phonological loop: The immediate serial recall of sequences of time intervals was shown to be related to the immediate serial recall of words (memory span). The results confirm the notion that working memory resources, and especially the phonological loop component, underlie the processing of auditorily presented temporal information with a duration of a few seconds.

  15. Time-dependent effects of cortisol on the contextualization of emotional memories.

    Science.gov (United States)

    van Ast, Vanessa A; Cornelisse, Sandra; Meeter, Martijn; Joëls, Marian; Kindt, Merel

    2013-12-01

    The inability to store fearful memories into their original encoding context is considered to be an important vulnerability factor for the development of anxiety disorders like posttraumatic stress disorder. Altered memory contextualization most likely involves effects of the stress hormone cortisol, acting via receptors located in the memory neurocircuitry. Cortisol via these receptors induces rapid nongenomic effects followed by slower genomic effects, which are thought to modulate cognitive function in opposite, complementary ways. Here, we targeted these time-dependent effects of cortisol during memory encoding and tested subsequent contextualization of emotional and neutral memories. In a double-blind, placebo-controlled design, 64 men were randomly assigned to one of three groups: 1) received 10 mg hydrocortisone 30 minutes (rapid cortisol effects) before a memory encoding task; 2) received 10 mg hydrocortisone 210 minutes (slow cortisol) before a memory encoding task; or 3) received placebo at both times. During encoding, participants were presented with neutral and emotional words in unique background pictures. Approximately 24 hours later, context dependency of their memories was assessed. Recognition data revealed that cortisol's rapid effects impair emotional memory contextualization, while cortisol's slow effects enhance it. Neutral memory contextualization remained unaltered by cortisol, irrespective of the timing of the drug. This study shows distinct time-dependent effects of cortisol on the contextualization of specifically emotional memories. The results suggest that rapid effects of cortisol may lead to impaired emotional memory contextualization, while slow effects of cortisol may confer protection against emotional memory generalization. © 2013 Society of Biological Psychiatry.

  16. Quantum stopwatch: how to store time in a quantum memory.

    Science.gov (United States)

    Yang, Yuxiang; Chiribella, Giulio; Hayashi, Masahito

    2018-05-01

    Quantum mechanics imposes a fundamental trade-off between the accuracy of time measurements and the size of the systems used as clocks. When the measurements of different time intervals are combined, the errors due to the finite clock size accumulate, resulting in an overall inaccuracy that grows with the complexity of the set-up. Here, we introduce a method that, in principle, eludes the accumulation of errors by coherently transferring information from a quantum clock to a quantum memory of the smallest possible size. Our method could be used to measure the total duration of a sequence of events with enhanced accuracy, and to reduce the amount of quantum communication needed to stabilize clocks in a quantum network.

  17. The Metaphor of Memory in Wordsworth's Spots of Time

    DEFF Research Database (Denmark)

    Møller, Lis

    2014-01-01

    on the turf. The insertion of the motif of the inscription turns the scene of execution into a literal site of memory, but it also functions as a metaphorical representation of the phenomenon of memory. The paper explores the implication of the inscription as metaphor of memory in a reading of the two spots....

  18. Temporal cognition: Connecting subjective time to perception, attention, and memory.

    Science.gov (United States)

    Matthews, William J; Meck, Warren H

    2016-08-01

    Time is a universal psychological dimension, but time perception has often been studied and discussed in relative isolation. Increasingly, researchers are searching for unifying principles and integrated models that link time perception to other domains. In this review, we survey the links between temporal cognition and other psychological processes. Specifically, we describe how subjective duration is affected by nontemporal stimulus properties (perception), the allocation of processing resources (attention), and past experience with the stimulus (memory). We show that many of these connections instantiate a "processing principle," according to which perceived time is positively related to perceptual vividity and the ease of extracting information from the stimulus. This empirical generalization generates testable predictions and provides a starting-point for integrated theoretical frameworks. By outlining some of the links between temporal cognition and other domains, and by providing a unifying principle for understanding these effects, we hope to encourage time-perception researchers to situate their work within broader theoretical frameworks, and that researchers from other fields will be inspired to apply their insights, techniques, and theorizing to improve our understanding of the representation and judgment of time. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  19. Exponential stability of continuous-time and discrete-time bidirectional associative memory networks with delays

    International Nuclear Information System (INIS)

    Liang Jinling; Cao Jinde

    2004-01-01

    First, convergence of continuous-time Bidirectional Associative Memory (BAM) neural networks are studied. By using Lyapunov functionals and some analysis technique, the delay-independent sufficient conditions are obtained for the networks to converge exponentially toward the equilibrium associated with the constant input sources. Second, discrete-time analogues of the continuous-time BAM networks are formulated and studied. It is shown that the convergence characteristics of the continuous-time systems are preserved by the discrete-time analogues without any restriction imposed on the uniform discretionary step size. An illustrative example is given to demonstrate the effectiveness of the obtained results

  20. A continuous time-resolved measure decoded from EEG oscillatory activity predicts working memory task performance.

    Science.gov (United States)

    Astrand, Elaine

    2018-06-01

    Working memory (WM), crucial for successful behavioral performance in most of our everyday activities, holds a central role in goal-directed behavior. As task demands increase, inducing higher WM load, maintaining successful behavioral performance requires the brain to work at the higher end of its capacity. Because it is depending on both external and internal factors, individual WM load likely varies in a continuous fashion. The feasibility to extract such a continuous measure in time that correlates to behavioral performance during a working memory task remains unsolved. Multivariate pattern decoding was used to test whether a decoder constructed from two discrete levels of WM load can generalize to produce a continuous measure that predicts task performance. Specifically, a linear regression with L2-regularization was chosen with input features from EEG oscillatory activity recorded from healthy participants while performing the n-back task, [Formula: see text]. The feasibility to extract a continuous time-resolved measure that correlates positively to trial-by-trial working memory task performance is demonstrated (r  =  0.47, p  performance before action (r  =  0.49, p  <  0.05). We show that the extracted continuous measure enables to study the temporal dynamics of the complex activation pattern of WM encoding during the n-back task. Specifically, temporally precise contributions of different spectral features are observed which extends previous findings of traditional univariate approaches. These results constitute an important contribution towards a wide range of applications in the field of cognitive brain-machine interfaces. Monitoring mental processes related to attention and WM load to reduce the risk of committing errors in high-risk environments could potentially prevent many devastating consequences or using the continuous measure as neurofeedback opens up new possibilities to develop novel rehabilitation techniques for

  1. 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.

  2. Finite-Time Stability for Fractional-Order Bidirectional Associative Memory Neural Networks with Time Delays

    Science.gov (United States)

    Xu, Chang-Jin; Li, Pei-Luan; Pang, Yi-Cheng

    2017-02-01

    This paper is concerned with fractional-order bidirectional associative memory (BAM) neural networks with time delays. Applying Laplace transform, the generalized Gronwall inequality and estimates of Mittag-Leffler functions, some sufficient conditions which ensure the finite-time stability of fractional-order bidirectional associative memory neural networks with time delays are obtained. Two examples with their simulations are given to illustrate the theoretical findings. Our results are new and complement previously known results. Supported by National Natural Science Foundation of China under Grant Nos.~61673008, 11261010, 11101126, Project of High-Level Innovative Talents of Guizhou Province ([2016]5651), Natural Science and Technology Foundation of Guizhou Province (J[2015]2025 and J[2015]2026), 125 Special Major Science and Technology of Department of Education of Guizhou Province ([2012]011) and Natural Science Foundation of the Education Department of Guizhou Province (KY[2015]482)

  3. 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.

  4. RTDB: A memory resident real-time object database

    International Nuclear Information System (INIS)

    Nogiec, Jerzy M.; Desavouret, Eugene

    2003-01-01

    RTDB is a fast, memory-resident object database with built-in support for distribution. It constitutes an attractive alternative for architecting real-time solutions with multiple, possibly distributed, processes or agents sharing data. RTDB offers both direct and navigational access to stored objects, with local and remote random access by object identifiers, and immediate direct access via object indices. The database supports transparent access to objects stored in multiple collaborating dispersed databases and includes a built-in cache mechanism that allows for keeping local copies of remote objects, with specifiable invalidation deadlines. Additional features of RTDB include a trigger mechanism on objects that allows for issuing events or activating handlers when objects are accessed or modified and a very fast, attribute based search/query mechanism. The overall architecture and application of RTDB in a control and monitoring system is presented

  5. Cognitive load and task condition in event- and time-based prospective memory: an experimental investigation.

    Science.gov (United States)

    Khan, Azizuddin; Sharma, Narendra K; Dixit, Shikha

    2008-09-01

    Prospective memory is memory for the realization of delayed intention. Researchers distinguish 2 kinds of prospective memory: event- and time-based (G. O. Einstein & M. A. McDaniel, 1990). Taking that distinction into account, the present authors explored participants' comparative performance under event- and time-based tasks. In an experimental study of 80 participants, the authors investigated the roles of cognitive load and task condition in prospective memory. Cognitive load (low vs. high) and task condition (event- vs. time-based task) were the independent variables. Accuracy in prospective memory was the dependent variable. Results showed significant differential effects under event- and time-based tasks. However, the effect of cognitive load was more detrimental in time-based prospective memory. Results also revealed that time monitoring is critical in successful performance of time estimation and so in time-based prospective memory. Similarly, participants' better performance on the event-based prospective memory task showed that they acted on the basis of environment cues. Event-based prospective memory was environmentally cued; time-based prospective memory required self-initiation.

  6. When Delays Improve Memory: Stabilizing Memory in Children May Require Time.

    Science.gov (United States)

    Darby, Kevin P; Sloutsky, Vladimir M

    2015-12-01

    Memory is critical for learning, cognition, and cognitive development. Recent work has suggested that preschool-age children are vulnerable to catastrophic levels of memory interference, in which new learning dramatically attenuates memory for previously acquired knowledge. In the work reported here, we investigated the effects of consolidation on children's memory by introducing a 48-hr delay between learning and testing. In Experiment 1, the delay improved children's memory and eliminated interference. Results of Experiment 2 suggest that the benefit of this delay is limited to situations in which children are given enough information to form complex memory structures. These findings have important implications for understanding consolidation processes and memory development. © The Author(s) 2015.

  7. Time perception, attention, and memory: a selective review.

    Science.gov (United States)

    Block, Richard A; Gruber, Ronald P

    2014-06-01

    This article provides a selective review of time perception research, mainly focusing on the authors' research. Aspects of psychological time include simultaneity, successiveness, temporal order, and duration judgments. In contrast to findings at interstimulus intervals or durations less than 3.0-5.0 s, there is little evidence for an "across-senses" effect of perceptual modality (visual vs. auditory) at longer intervals or durations. In addition, the flow of time (events) is a pervasive perceptual illusion, and we review evidence on that. Some temporal information is encoded All rights reserved. relatively automatically into memory: People can judge time-related attributes such as recency, frequency, temporal order, and duration of events. Duration judgments in prospective and retrospective paradigms reveal differences between them, as well as variables that moderate the processes involved. An attentional-gate model is needed to account for prospective judgments, and a contextual-change model is needed to account for retrospective judgments. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. 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.

  9. 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.

  10. Timely sleep facilitates declarative memory consolidation in infants

    OpenAIRE

    Seehagen, Sabine; Konrad, Carolin; Herbert, Jane S.; Schneider, Silvia

    2015-01-01

    The potential benefits of infant sleep for memory processing are largely unexplored. Here we show evidence that having an extended nap (≥30 min) within 4 h of learning helps 6- and 12-month-old infants to retain their memories for new behaviors across a 4- and 24-h delay. These results suggest that infants rely on frequent naps for the formation of long-term memories.

  11. Fast-Response-Time Shape-Memory-Effect Foam Actuators

    Science.gov (United States)

    Jardine, Peter

    2010-01-01

    Bulk shape memory alloys, such as Nitinol or CuAlZn, display strong recovery forces undergoing a phase transformation after being strained in their martensitic state. These recovery forces are used for actuation. As the phase transformation is thermally driven, the response time of the actuation can be slow, as the heat must be passively inserted or removed from the alloy. Shape memory alloy TiNi torque tubes have been investigated for at least 20 years and have demonstrated high actuation forces [3,000 in.-lb (approximately equal to 340 N-m) torques] and are very lightweight. However, they are not easy to attach to existing structures. Adhesives will fail in shear at low-torque loads and the TiNi is not weldable, so that mechanical crimp fits have been generally used. These are not reliable, especially in vibratory environments. The TiNi is also slow to heat up, as it can only be heated indirectly using heater and cooling must be done passively. This has restricted their use to on-off actuators where cycle times of approximately one minute is acceptable. Self-propagating high-temperature synthesis (SHS) has been used in the past to make porous TiNi metal foams. Shape Change Technologies has been able to train SHS derived TiNi to exhibit the shape memory effect. As it is an open-celled material, fast response times were observed when the material was heated using hot and cold fluids. A methodology was developed to make the open-celled porous TiNi foams as a tube with integrated hexagonal ends, which then becomes a torsional actuator with fast response times. Under processing developed independently, researchers were able to verify torques of 84 in.-lb (approximately equal to 9.5 Nm) using an actuator weighing 1.3 oz (approximately equal to 37 g) with very fast (less than 1/16th of a second) initial response times when hot and cold fluids were used to facilitate heat transfer. Integrated structural connections were added as part of the net shape process, eliminating

  12. Mental time travel : A conceptual overview of social psychological perspectives on a fundamental human capacity

    NARCIS (Netherlands)

    Epstude, K.; Peetz, J.

    Humans have the unique capacity to mentally travel through time, that is, to reflect on the past, anticipate the future, and construct alternate realities in their minds. The ability to mentally travel through time affects a variety of social psychological topics. Representations of events can

  13. Self-Efficacy Beliefs and Mental Time Travel Ability: Uncovering a Hidden Relationship in Educational Settings

    Science.gov (United States)

    Eren, Altay

    2009-01-01

    The aim of this study was threefold: first, it was to explore the profiles of student teachers' mental time travel ability; second, it was to examine the relationship between student teachers' mental time travel ability and self-efficacy beliefs; and third, it was to investigate the role of self-efficacy beliefs in relationship between the past…

  14. "I can see clearly now": The effect of cue imageability on mental time travel

    DEFF Research Database (Denmark)

    Rasmussen, Katrine Willemoes; Berntsen, Dorthe

    2014-01-01

    Mental time travel (MTT) is the ability to mentally project oneself backward or forward in time, in order to remember an event from one’s personal past or to imagine a possible event in one’s personal future. Recent work has suggested that, although past and future MTT may rely on shared...

  15. Does Involuntary Mental Time Travel Make Sense in Prospective Teachers' Feelings and Behaviors during Lessons?

    Science.gov (United States)

    Eren, Altay; Yesilbursa, Amanda

    2013-01-01

    This study examined the effects of involuntary mental time travel into the past and into the future on prospective teachers' feelings and behaviors during the period of a class hour. A total of 110 prospective teachers participated voluntarily in the study. The results of the present study showed that (a) the involuntary mental time travel into…

  16. Making Decisions with the Future in Mind: Developmental and Comparative Identification of Mental Time Travel

    Science.gov (United States)

    Suddendorf, T.; Busby, J.

    2005-01-01

    Mechanisms that produce behavior which increase future survival chances provide an adaptive advantage. The flexibility of human behavior is at least partly the result of one such mechanism, our ability to travel mentally in time and entertain potential future scenarios. We can study mental time travel in children using language. Current results…

  17. Regenerative memory in time-delayed neuromorphic photonic resonators

    Science.gov (United States)

    Romeira, B.; Avó, R.; Figueiredo, José M. L.; Barland, S.; Javaloyes, J.

    2016-01-01

    We investigate a photonic regenerative memory based upon a neuromorphic oscillator with a delayed self-feedback (autaptic) connection. We disclose the existence of a unique temporal response characteristic of localized structures enabling an ideal support for bits in an optical buffer memory for storage and reshaping of data information. We link our experimental implementation, based upon a nanoscale nonlinear resonant tunneling diode driving a laser, to the paradigm of neuronal activity, the FitzHugh-Nagumo model with delayed feedback. This proof-of-concept photonic regenerative memory might constitute a building block for a new class of neuron-inspired photonic memories that can handle high bit-rate optical signals.

  18. Temporal Prediction Errors Affect Short-Term Memory Scanning Response Time.

    Science.gov (United States)

    Limongi, Roberto; Silva, Angélica M

    2016-11-01

    The Sternberg short-term memory scanning task has been used to unveil cognitive operations involved in time perception. Participants produce time intervals during the task, and the researcher explores how task performance affects interval production - where time estimation error is the dependent variable of interest. The perspective of predictive behavior regards time estimation error as a temporal prediction error (PE), an independent variable that controls cognition, behavior, and learning. Based on this perspective, we investigated whether temporal PEs affect short-term memory scanning. Participants performed temporal predictions while they maintained information in memory. Model inference revealed that PEs affected memory scanning response time independently of the memory-set size effect. We discuss the results within the context of formal and mechanistic models of short-term memory scanning and predictive coding, a Bayes-based theory of brain function. We state the hypothesis that our finding could be associated with weak frontostriatal connections and weak striatal activity.

  19. Analog-to-digital conversion using custom CMOS analog memory for the EOS time projection chamber

    International Nuclear Information System (INIS)

    Lee, K.L.; Arthur, A.A.; Jones, R.W.; Matis, H.S.; Nakamura, M.; Kleinfelder, S.A.; Ritter, H.G.; Wienman, H.H.

    1990-01-01

    This paper describes the multiplexing scheme of custom CMOS analog memory integrated circuits, 16 channels x 256 cells, into analog to digital converters (ADC's) to handle 15,360 signal channels of a time projection, chamber detector system. Primary requirements of this system are high density, low power and large dynamic range. The analog memory device multiplexing scheme was designed to digitize the information stored in the memory cells. The digitization time of the ADC's and the settling times for the memory unit were carefully interleaved to optimize the performance and timing during the multiplexing operation. This kept the total number of ADC's, a costly and power dissipative component, to an acceptable minimum

  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. Modeling Confidence and Response Time in Recognition Memory

    Science.gov (United States)

    Ratcliff, Roger; Starns, Jeffrey J.

    2009-01-01

    A new model for confidence judgments in recognition memory is presented. In the model, the match between a single test item and memory produces a distribution of evidence, with better matches corresponding to distributions with higher means. On this match dimension, confidence criteria are placed, and the areas between the criteria under the…

  2. Time, not sleep, unbinds contexts from item memory

    NARCIS (Netherlands)

    Cox, R.; Tijdens, R.R.; Meeter, M.; Sweegers, C.M.; Talamini, L.M.

    2014-01-01

    Contextual cues are known to benefit memory retrieval, but whether and how sleep affects this context effect remains unresolved. We manipulated contextual congruence during memory retrieval in human volunteers across 12 h and 24 h intervals beginning with either sleep or wakefulness. Our data

  3. Alternating-time temporal logic with finite-memory strategies

    DEFF Research Database (Denmark)

    Vester, Steen

    2013-01-01

    on finite-memory strategies. One where the memory size allowed is bounded and one where the memory size is unbounded (but must be finite). This is motivated by the high complexity of model-checking with perfect recall semantics and the severe limitations of memoryless strategies. We show that both types...... of semantics introduced are different from perfect recall and memoryless semantics and next focus on the decidability and complexity of model-checking in both complete and incomplete information games for ATL/ATL*. In particular, we show that the complexity of model-checking with bounded-memory semantics...... is Delta_2p-complete for ATL and PSPACE-complete for ATL* in incomplete information games just as in the memoryless case. We also present a proof that ATL and ATL* model-checking is undecidable for n >= 3 players with finite-memory semantics in incomplete information games....

  4. Memory and time: Backward and forward telescoping in Alzheimer's disease.

    Science.gov (United States)

    El Haj, Mohamad; Janssen, Steve M J; Antoine, Pascal

    2017-10-01

    Backward and forward telescoping are opposite timing biases. The former refers to misattributing events to earlier dates, whereas the latter refers to misattributing events to later dates. The present study investigated both biases in participants with Alzheimer's Disease (AD) and healthy older adults, matched on age, sex, and education level. Participants were asked to recall the years when five remote and five recent public events had occurred. They were also assessed with a cognitive and clinical battery that included a context memory task on which they had to associate letters and locations. Results showed backward telescoping for recent events and forward telescoping for remote events in AD participants and older adults. Furthermore, poorer context recall was observed in AD participants and older adults displaying backward telescoping than in those displaying forward telescoping. These findings suggest an association between the amount of contextual information recalled and the direction of the timing bias. Backward telescoping can be associated with deficiencies in retrieving context characteristics of events, which have been associated with retrograde amnesia and pathological changes to the hippocampus in AD. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Grading Gradients: Evaluating Evidence for Time-dependent Memory Reorganization in Experimental Animals

    Directory of Open Access Journals (Sweden)

    Katherine G. Akers

    2009-01-01

    Full Text Available In humans, hippocampal damage typically produces temporally graded retrograde amnesia, with relative sparing of remote memories compared to recent memories. This observation led to the idea that as memories age, they are reorganized in a time-dependent manner. Here, we evaluate evidence for time-dependent memory reorganization in animal models. We conclude that, although hippocampal lesions may not always produce temporal gradients under all conditions, studies using alternate experimental approaches consistently support the idea that memories reorganize over time—becoming less dependent on the hippocampus and more dependent on a cortical network. We further speculate on the processes that drive memory reorganization such as sleep, memory reactivation, synaptic plasticity, and neurogenesis.

  6. Memory processing in great apes: the effect of time and sleep.

    Science.gov (United States)

    Martin-Ordas, Gema; Call, Josep

    2011-12-23

    Following encoding, memory remains temporarily vulnerable to disruption. Consolidation refers to offline time-dependent processes that continue after encoding and stabilize, transform or enhance the memory trace. Memory consolidation resulting from sleep has been reported for declarative and non-declarative memories in humans. We first investigated the temporal course of memory retrieval in chimpanzees, bonobos and orangutans. We found that the amount of retrieved information was time dependent: apes' performance degraded after 1 and 2 h, stabilized after 4 h, started to increase after 8 and 12 h and fully recovered after 24 h. Second, we show that although memories during wakefulness were highly vulnerable to interference from events similar to those witnessed during the original encoding event, an intervening period of sleep not only stabilized apes' memories into more permanent ones but also protected them against interference.

  7. Clocking In Time to Gate Memory Processes: The Circadian Clock Is Part of the Ins and Outs of Memory

    Directory of Open Access Journals (Sweden)

    Oliver Rawashdeh

    2018-01-01

    Full Text Available Learning, memory consolidation, and retrieval are processes known to be modulated by the circadian (circa: about; dies: day system. The circadian regulation of memory performance is evolutionarily conserved, independent of the type and complexity of the learning paradigm tested, and not specific to crepuscular, nocturnal, or diurnal organisms. In mammals, long-term memory (LTM formation is tightly coupled to de novo gene expression of plasticity-related proteins and posttranslational modifications and relies on intact cAMP/protein kinase A (PKA/protein kinase C (PKC/mitogen-activated protein kinase (MAPK/cyclic adenosine monophosphate response element-binding protein (CREB signaling. These memory-essential signaling components cycle rhythmically in the hippocampus across the day and night and are clearly molded by an intricate interplay between the circadian system and memory. Important components of the circadian timing mechanism and its plasticity are members of the Period clock gene family (Per1, Per2. Interestingly, Per1 is rhythmically expressed in mouse hippocampus. Observations suggest important and largely unexplored roles of the clock gene protein PER1 in synaptic plasticity and in the daytime-dependent modulation of learning and memory. Here, we review the latest findings on the role of the clock gene Period 1 (Per1 as a candidate molecular and mechanistic blueprint for gating the daytime dependency of memory processing.

  8. [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.

  9. Time to recurrence of mental health-related absence from work.

    Science.gov (United States)

    Norder, G; Hoedeman, R; de Bruin, J; van Rhenen, W; Roelen, C A M

    2015-10-01

    It is unclear when occupational health providers should re-evaluate workers after mental health-related absences from work. To investigate the time to recurrence of mental health-related absences, stratified by International Classification of Diseases-Tenth Revision (ICD-10) diagnostic categories. A 10-year observational study of workers employed at a steel mill. Sickness absence data were retrieved from an occupational health register. Mental health-related absences were defined as absence due to emotional disturbance or mental and behavioural disorders. The first mental health-related absence since baseline was called the index episode. Recurrences were defined as mental health-related absences occurring >28 days after recovery from the index episode. The frequency of recurrent mental health-related absence was assessed by the recurrence density (RD) per 1000 person-years. The time to recurrent mental health-related absence was investigated by Kaplan-Meier survival analysis. Of 15461 workers, 391 had recurrent mental health-related absences. RD was 30.5, 34.3, 29.9 and 37.7 per 1000 person-years after index episodes due to emotional disturbance, mood disorders, neurotic disorders and other psychiatric disorders, respectively. RDs did not differ across ICD-10 diagnostic categories. The median time to recurrent mental health-related absence was 15.2 months [95% confidence interval (CI) 12.6-17.7] and was shortest for mood disorders (5.2, 95% CI 1.4-8.9 months) and specific psychiatric disorders (5.3, 95% CI 1.0-13.1 months). Based on this observational study, we suggest that occupational and primary health care providers consider reviewing the mental health status of workers 6 months after recovery from mental health-related absence. © The Author 2015. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Mental Toughness Moderates Social Loafing in Cycle Time-Trial Performance.

    Science.gov (United States)

    Haugen, Tommy; Reinboth, Michael; Hetlelid, Ken J; Peters, Derek M; Høigaard, Rune

    2016-09-01

    The purpose of this study was to determine if mental toughness moderated the occurrence of social loafing in cycle time-trial performance. Twenty-seven men (Mage = 17.7 years, SD = 0.6) completed the Sport Mental Toughness Questionnaire prior to completing a 1-min cycling trial under 2 conditions: once with individual performance identified, and once in a group with individual performance not identified. Using a median split of the mental toughness index, participants were divided into high and low mental toughness groups. Cycling distance was compared using a 2 (trial) × 2 (high-low mental toughness) analysis of variance. We hypothesized that mentally tough participants would perform equally well under both conditions (i.e., no indication of social loafing) compared with low mentally tough participants, who would perform less well when their individual performance was not identifiable (i.e., demonstrating the anticipated social loafing effect). The high mental toughness group demonstrated consistent performance across both conditions, while the low mental toughness group reduced their effort in the non-individually identifiable team condition. The results confirm that (a) clearly identifying individual effort/performance is an important situational variable that may impact team performance and (b) higher perceived mental toughness has the ability to negate the tendency to loaf.

  11. 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.

  12. The Gift of Time? School Starting Age and Mental Health

    DEFF Research Database (Denmark)

    Sievertsen, Hans Henrik; S. Dee, Thomas

    2018-01-01

    influences student outcomes by relying on linked Danish survey and register data that include several distinct, widely used, and validated measures of mental health that are reported out-of-school among similarly aged children. We estimate the causal effects of delayed school enrollment using a "fuzzy.......7), a measure of self regulation with strong negative links to student achievement. We also find that this large and targeted effect persists at age 11. However, the estimated effects of school starting age on other mental-health constructs, which have weaker links to subsequent student achievement, are smaller......In many developed countries, children now begin their formal schooling at an older age. However, a growing body of empirical studies provides little evidence that such schooling delays improve educational and economic outcomes. This study presents new evidence on whether school starting age...

  13. Leisure Time Activities and Mental Health in Informal Dementia Caregivers.

    Science.gov (United States)

    Schüz, Benjamin; Czerniawski, Alana; Davie, Nicola; Miller, Lisa; Quinn, Michael G; King, Carolyn; Carr, Andrea; Elliott, Kate-Ellen J; Robinson, Andrew; Scott, Jenn L

    2015-07-01

    Dementia prevalence and the demand for dementia care are increasing. Informal caregiving accounts for a large proportion of dementia care, but can come at high cost for caregivers. Informal dementia caregivers are at higher risk for mental health problems than the general population. This study examines whether perceived change in leisure activities is one working mechanism linking stress and burden experience in dementia caregiving to lower mental health (depressive symptoms, anxiety symptoms, and reduced satisfaction with life), and whether there are group-based leisure activities that can buffer this detrimental effect. A total of 346 informal Australian dementia caregivers (88.15% female, age 18-82 years) participated in an online study. Mediation and moderation analyses using multiple regression demonstrated that perceived changes in leisure activities linked caregiving stress and burden to lower mental health, and that membership in groups engaging in affiliation or social activities attenuates negative effects of caregiving. Informal dementia caregivers benefit from satisfying leisure activities. In particular, engaging in social activities and self-help groups buffered the negative impact of caregiving. © 2015 The International Association of Applied Psychology.

  14. Long memory of financial time series and hidden Markov models with time-varying parameters

    DEFF Research Database (Denmark)

    Nystrup, Peter; Madsen, Henrik; Lindström, Erik

    Hidden Markov models are often used to capture stylized facts of daily returns and to infer the hidden state of financial markets. Previous studies have found that the estimated models change over time, but the implications of the time-varying behavior for the ability to reproduce the stylized...... facts have not been thoroughly examined. This paper presents an adaptive estimation approach that allows for the parameters of the estimated models to be time-varying. It is shown that a two-state Gaussian hidden Markov model with time-varying parameters is able to reproduce the long memory of squared...... daily returns that was previously believed to be the most difficult fact to reproduce with a hidden Markov model. Capturing the time-varying behavior of the parameters also leads to improved one-step predictions....

  15. Exploring the Effects of Working Memory on Time Perception in Attention Deficit Hyperactivity Disorder.

    Science.gov (United States)

    Lee, Hom-Yi; Yang, En-Lin

    2018-01-01

    Children with attention deficit hyperactivity disorder (ADHD) are often reported to have deficits of time perception. However, there is a strong relation between performance on tasks of working memory and time perception. Thus, it is possible that the poor performance of children with ADHD on time perception results from their deficit of working memory. In this study, the working memory of participants was separately assessed; therefore, we could explore the relationship between working memory and time perception of children with ADHD. Fifty-six children with ADHD and those of healthy controls completed tasks measuring working memory and time perception. The results showed that the time discrimination ability of children with ADHD was poorer than that of controls. However, there was a strong association between time perception and working memory. After controlling working memory and intelligence, the time discrimination ability of children with ADHD was not significantly poorer than that of controls. We suggest that there is an interdependent relationship between time perception and working memory for children with ADHD.

  16. Caffeine Enhances Memory Performance in Young Adults during Their Non-optimal Time of Day.

    Science.gov (United States)

    Sherman, Stephanie M; Buckley, Timothy P; Baena, Elsa; Ryan, Lee

    2016-01-01

    Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated), college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1). During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not implicit memory. Caffeine did not alter memory performance in the afternoon. In Experiment 2, participants engaged in cardiovascular exercise in order to examine whether increases in physiological arousal similarly improved memory. Despite clear increases in physiological arousal, exercise did not improve memory performance compared to a stretching control condition. These results suggest that caffeine has a specific benefit for memory during students' non-optimal time of day - early morning. These findings have real-world implications for students taking morning exams.

  17. Caffeine enhances memory performance in young adults during their non-optimal time of day

    Directory of Open Access Journals (Sweden)

    Stephanie M Sherman

    2016-11-01

    Full Text Available Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated, college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1. During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not implicit memory. Caffeine did not alter memory performance in the afternoon. In Experiment 2, participants engaged in cardiovascular exercise in order to examine whether increases in physiological arousal similarly improved memory. Despite clear increases in arousal, exercise did not improve memory performance compared to a stretching control condition. These results suggest that caffeine has a specific benefit for memory during students’ non-optimal time of day – early morning. These findings have real-world implications for students taking morning exams.

  18. The timing of associative memory formation: frontal lobe and anterior medial temporal lobe activity at associative binding predicts memory

    Science.gov (United States)

    Hales, J. B.

    2011-01-01

    The process of associating items encountered over time and across variable time delays is fundamental for creating memories in daily life, such as for stories and episodes. Forming associative memory for temporally discontiguous items involves medial temporal lobe structures and additional neocortical processing regions, including prefrontal cortex, parietal lobe, and lateral occipital regions. However, most prior memory studies, using concurrently presented stimuli, have failed to examine the temporal aspect of successful associative memory formation to identify when activity in these brain regions is predictive of associative memory formation. In the current study, functional MRI data were acquired while subjects were shown pairs of sequentially presented visual images with a fixed interitem delay within pairs. This design allowed the entire time course of the trial to be analyzed, starting from onset of the first item, across the 5.5-s delay period, and through offset of the second item. Subjects then completed a postscan recognition test for the items and associations they encoded during the scan and their confidence for each. After controlling for item-memory strength, we isolated brain regions selectively involved in associative encoding. Consistent with prior findings, increased regional activity predicting subsequent associative memory success was found in anterior medial temporal lobe regions of left perirhinal and entorhinal cortices and in left prefrontal cortex and lateral occipital regions. The temporal separation within each pair, however, allowed extension of these findings by isolating the timing of regional involvement, showing that increased response in these regions occurs during binding but not during maintenance. PMID:21248058

  19. Color memory matching: time effect and other factors

    OpenAIRE

    Pérez Carpinell, Jaime; Baldoví, Rosa; Fez Saiz, Dolores de; Castro, José

    1998-01-01

    The methods of simultaneous and successive, or memory, color matching have been compared for 10 color reference samples distributed in two groups each performed by 50 observers (25 men and 25 women). Our results, obtained with a total of 200 Munsell color chips arrayed on 10 gray cardboard panels, indicated that: a)while by simultaneous matching the mean color differences obtained are, in most cases, lower than 1 Cielab unit, those obtained by memory are generally higer; b) the worst remember...

  20. Regenerative memory in time-delayed neuromorphic photonic resonators

    OpenAIRE

    Romeira, B.; Avó, R.; Figueiredo, José M. L.; Barland, S.; Javaloyes, J.

    2016-01-01

    We investigate a photonic regenerative memory based upon a neuromorphic oscillator with a delayed self-feedback (autaptic) connection. We disclose the existence of a unique temporal response characteristic of localized structures enabling an ideal support for bits in an optical buffer memory for storage and reshaping of data information. We link our experimental implementation, based upon a nanoscale nonlinear resonant tunneling diode driving a laser, to the paradigm of neuronal activity, the...

  1. 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 ...

  2. The Role of Nitric Oxide in Memory is Modulated by Diurnal Time

    Directory of Open Access Journals (Sweden)

    Stephanie L. Gage

    2014-04-01

    Full Text Available Nitric oxide (NO is thought to play an important neuromodulatory role in the olfactory system. This modulation has been suggested to be particularly important for olfactory learning and memory in the antennal lobe (the primary olfactory network in invertebrates. We are using the hawkmoth, Manduca sexta, to further investigate the role of NO in olfactory memory. Recent findings suggest that NO affects short-term memory traces and that NO concentration fluctuates with the light cycle. This gives rise to the hypothesis that NO may be involved in the connection between memory and circadian rhythms. In this study, we explore the role of diurnal time and NO in memory by altering the time of day when associative-olfactory conditioning is performed. We find a strong effect of NO on short-term memory, and two surprising effects of diurnal time. We find that (1 at certain time points, NO affects longer traces of memory in addition to short-term memory, and (2 when conditioning is performed close to the light cycle switches—both from light to dark and dark to light—NO does not significantly affect memory at all. These findings suggest an intriguing functional role for NO in olfactory conditioning that is modulated as a function of diurnal time.

  3. 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.

  4. Real-time Continuous Assessment Method for Mental and Physiological Condition using Heart Rate Variability

    Science.gov (United States)

    Yoshida, Yutaka; Yokoyama, Kiyoko; Ishii, Naohiro

    It is necessary to monitor the daily health condition for preventing stress syndrome. In this study, it was proposed the method assessing the mental and physiological condition, such as the work stress or the relaxation, using heart rate variability at real time and continuously. The instantanuous heart rate (HR), and the ratio of the number of extreme points (NEP) and the number of heart beats were calculated for assessing mental and physiological condition. In this method, 20 beats heart rate were used to calculate these indexes. These were calculated in one beat interval. Three conditions, which are sitting rest, performing mental arithmetic and watching relaxation movie, were assessed using our proposed algorithm. The assessment accuracies were 71.9% and 55.8%, when performing mental arithmetic and watching relaxation movie respectively. In this method, the mental and physiological condition was assessed using only 20 regressive heart beats, so this method is considered as the real time assessment method.

  5. Cost Analysis for Real-time Java Scoped-memory Areas

    Directory of Open Access Journals (Sweden)

    Delvin Defoe

    2007-08-01

    Full Text Available Java has recently joined C and C++ as a development platform for real-time and embedded applications. Java's garbage collection, while generally a useful feature, can be problematic for these applications: garbage collection occurs at unpredictable times and its latency is typically unbounded. This can compromise necessary real-time guarantees. To overcome these limitations, the Real-Time for Java Expert Group (RTJEG proposed the Real-Time Specification for Java (RTSJ, which introduced new memory models and new threads to utilize those models. One such memory model uses scoped-memory areas, which work best in the context of a NoHeapRealtimeThread (NHRT. Although much work has been done with scoped-memory areas and NHRTs, there is no system-independent analysis of their costs. In this article we present an asymptotic analysis for RTSJ scoped-memory areas and NHRTs.

  6. Memory retrieval and the passage of time: from reconsolidation and strengthening to extinction.

    Science.gov (United States)

    Inda, Maria Carmen; Muravieva, Elizaveta V; Alberini, Cristina M

    2011-02-02

    An established memory can be made transiently labile if retrieved or reactivated. Over time, it becomes again resistant to disruption and this process that renders the memory stable is termed reconsolidation. The reasons why a memory becomes labile after retrieval and reconsolidates still remains debated. Here, using inhibitory avoidance learning in rats, we provide evidence that retrievals of a young memory, which are accompanied by its reconsolidation, result in memory strengthening and contribute to its overall consolidation. This function associated to reconsolidation is temporally limited. With the passage of time, the stored memory undergoes important changes, as revealed by the behavioral outcomes of its retrieval. Over time, without explicit retrievals, memory first strengthens and becomes refractory to both retrieval-dependent interference and strengthening. At later times, the same retrievals that lead to reconsolidation of a young memory extinguish an older memory. We conclude that the storage of information is very dynamic and that its temporal evolution regulates behavioral outcomes. These results are important for potential clinical applications.

  7. Phenotypic and Functional Alterations in Circulating Memory CD8 T Cells with Time after Primary Infection.

    Directory of Open Access Journals (Sweden)

    Matthew D Martin

    2015-10-01

    Full Text Available Memory CD8 T cells confer increased protection to immune hosts upon secondary viral, bacterial, and parasitic infections. The level of protection provided depends on the numbers, quality (functional ability, and location of memory CD8 T cells present at the time of infection. While primary memory CD8 T cells can be maintained for the life of the host, the full extent of phenotypic and functional changes that occur over time after initial antigen encounter remains poorly characterized. Here we show that critical properties of circulating primary memory CD8 T cells, including location, phenotype, cytokine production, maintenance, secondary proliferation, secondary memory generation potential, and mitochondrial function change with time after infection. Interestingly, phenotypic and functional alterations in the memory population are not due solely to shifts in the ratio of effector (CD62Llo and central memory (CD62Lhi cells, but also occur within defined CD62Lhi memory CD8 T cell subsets. CD62Lhi memory cells retain the ability to efficiently produce cytokines with time after infection. However, while it is was not formally tested whether changes in CD62Lhi memory CD8 T cells over time occur in a cell intrinsic manner or are due to selective death and/or survival, the gene expression profiles of CD62Lhi memory CD8 T cells change, phenotypic heterogeneity decreases, and mitochondrial function and proliferative capacity in either a lymphopenic environment or in response to antigen re-encounter increase with time. Importantly, and in accordance with their enhanced proliferative and metabolic capabilities, protection provided against chronic LCMV clone-13 infection increases over time for both circulating memory CD8 T cell populations and for CD62Lhi memory cells. Taken together, the data in this study reveal that memory CD8 T cells continue to change with time after infection and suggest that the outcome of vaccination strategies designed to elicit

  8. Memory for Random Time Patterns in Audition, Touch, and Vision.

    Science.gov (United States)

    Kang, HiJee; Lancelin, Denis; Pressnitzer, Daniel

    2018-03-22

    Perception deals with temporal sequences of events, like series of phonemes for audition, dynamic changes in pressure for touch textures, or moving objects for vision. Memory processes are thus needed to make sense of the temporal patterning of sensory information. Recently, we have shown that auditory temporal patterns could be learned rapidly and incidentally with repeated exposure [Kang et al., 2017]. Here, we tested whether rapid incidental learning of temporal patterns was specific to audition, or if it was a more general property of sensory systems. We used a same behavioral task in three modalities: audition, touch, and vision, for stimuli having identical temporal statistics. Participants were presented with sequences of acoustic pulses for audition, motion pulses to the fingertips for touch, or light pulses for vision. Pulses were randomly and irregularly spaced, with all inter-pulse intervals in the sub-second range and all constrained to be longer than the temporal acuity in any modality. This led to pulse sequences with an average inter-pulse interval of 166 ms, a minimum inter-pulse interval of 60 ms, and a total duration of 1.2 s. Results showed that, if a random temporal pattern re-occurred at random times during an experimental block, it was rapidly learned, whatever the sensory modality. Moreover, patterns first learned in the auditory modality displayed transfer of learning to either touch or vision. This suggests that sensory systems may be exquisitely tuned to incidentally learn re-occurring temporal patterns, with possible cross-talk between the senses. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  9. Visual working memory as visual attention sustained internally over time.

    Science.gov (United States)

    Chun, Marvin M

    2011-05-01

    Visual working memory and visual attention are intimately related, such that working memory encoding and maintenance reflects actively sustained attention to a limited number of visual objects and events important for ongoing cognition and action. Although attention is typically considered to operate over perceptual input, a recent taxonomy proposes to additionally consider how attention can be directed to internal perceptual representations in the absence of sensory input, as well as other internal memories, choices, and thoughts (Chun, Golomb, & Turk-Browne, 2011). Such internal attention enables prolonged binding of features into integrated objects, along with enhancement of relevant sensory mechanisms. These processes are all limited in capacity, although different types of working memory and attention, such as spatial vs. object processing, operate independently with separate capacity. Overall, the success of maintenance depends on the ability to inhibit both external (perceptual) and internal (cognitive) distraction. Working memory is the interface by which attentional mechanisms select and actively maintain relevant perceptual information from the external world as internal representations within the mind. Copyright © 2011. Published by Elsevier Ltd.

  10. A continuous time-resolved measure decoded from EEG oscillatory activity predicts working memory task performance

    Science.gov (United States)

    Astrand, Elaine

    2018-06-01

    Objective. Working memory (WM), crucial for successful behavioral performance in most of our everyday activities, holds a central role in goal-directed behavior. As task demands increase, inducing higher WM load, maintaining successful behavioral performance requires the brain to work at the higher end of its capacity. Because it is depending on both external and internal factors, individual WM load likely varies in a continuous fashion. The feasibility to extract such a continuous measure in time that correlates to behavioral performance during a working memory task remains unsolved. Approach. Multivariate pattern decoding was used to test whether a decoder constructed from two discrete levels of WM load can generalize to produce a continuous measure that predicts task performance. Specifically, a linear regression with L2-regularization was chosen with input features from EEG oscillatory activity recorded from healthy participants while performing the n-back task, n\\in [1,2] . Main results. The feasibility to extract a continuous time-resolved measure that correlates positively to trial-by-trial working memory task performance is demonstrated (r  =  0.47, p  <  0.05). It is furthermore shown that this measure allows to predict task performance before action (r  =  0.49, p  <  0.05). We show that the extracted continuous measure enables to study the temporal dynamics of the complex activation pattern of WM encoding during the n-back task. Specifically, temporally precise contributions of different spectral features are observed which extends previous findings of traditional univariate approaches. Significance. These results constitute an important contribution towards a wide range of applications in the field of cognitive brain–machine interfaces. Monitoring mental processes related to attention and WM load to reduce the risk of committing errors in high-risk environments could potentially prevent many devastating consequences or

  11. Functional mental capacity, treatment as usual and time: magnitude of change in secure hospital patients with major mental illness.

    Science.gov (United States)

    Dornan, Julieanne; Kennedy, Miriam; Garland, Jackie; Rutledge, Emer; Kennedy, Harry G

    2015-10-14

    Decision making ability can change with time, depending on mental or physical health. Little is known about the factors that determine this change and the relationship of capacity to time. As a pilot for studies using functional mental capacities as an outcome measure, we sought to quantify this relationship measuring change over time using competence assessment tools, and rating scales for symptoms and global function. We assessed 37 inpatients in a secure psychiatric hospital. All patients met the diagnostic and statistical manual of mental disorders-fourth edition and International classification of diseases, 10th edition criteria for an Axis 1 mental illness, all with psychosis. Patients were interviewed twice a mean of 323 days apart (median 176 days range 17-1221 days). The MacArthur competence assessment tools for consent to treatment (MacCAT-T) and fitness to plead (MacCAT-FP) were used to quantify functional capacity along with the Positive and Negative Syndrome Scale (PANSS) and global assessment of function (GAF) scale. A comparison was also made between those patients prescribed clozapine in comparison to other antipsychotics. The number judged by treating psychiatrists to lack capacity either to make a treatment choice or to plead in court fell from 35 to 8%. Change was greatest for those admitted within the previous 9 months. The measures of capacity improved between time 1 and time 2 for both consent to treatment and fitness to plead. The measures of capacity improved with positive symptoms within the PANSS and with GAF scores. Those with shorter lengths of stay at baseline had the greatest improvements in the MacCAT-FP scores. Effect sizes were medium or large (0.3-0.7+). As expected, patients prescribed clozapine had larger changes in functional mental capacities and larger effect sizes than those prescribed other psychotropics. The results show a strong relationship between the clinicians' assessment of capacity and structured rating scales. We

  12. Why are you late? Investigating the role of time management in time-based prospective memory.

    Science.gov (United States)

    Waldum, Emily R; McDaniel, Mark A

    2016-08-01

    Time-based prospective memory tasks (TBPM) are those that are to be performed at a specific future time. Contrary to typical laboratory TBPM tasks (e.g., hit the Z key every 5 min), many real-world TBPM tasks require more complex time-management processes. For instance, to attend an appointment on time, one must estimate the duration of the drive to the appointment and then use this estimate to create and execute a secondary TBPM intention (e.g., "I need to start driving by 1:30 to make my 2:00 appointment on time"). Future under- and overestimates of drive time can lead to inefficient TBPM performance with the former lending to missed appointments and the latter to long stints in the waiting room. Despite the common occurrence of complex TBPM tasks in everyday life, to date, no studies have investigated how components of time management, including time estimation, affect behavior in such complex TBPM tasks. Therefore, the current study aimed to investigate timing biases in both older and younger adults and, further, to determine how such biases along with additional time management components including planning and plan fidelity influence complex TBPM performance. Results suggest for the first time that younger and older adults do not always utilize similar timing strategies, and as a result, can produce differential timing biases under the exact same environmental conditions. These timing biases, in turn, play a vital role in how efficiently both younger and older adults perform a later TBPM task that requires them to utilize their earlier time estimate. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  13. Aversive olfactory associative memory loses odor specificity over time.

    Science.gov (United States)

    König, Christian; Antwi-Adjei, Emmanuel; Ganesan, Mathangi; Kilonzo, Kasyoka; Viswanathan, Vignesh; Durairaja, Archana; Voigt, Anne; Yarali, Ayse

    2017-05-01

    Avoiding associatively learned predictors of danger is crucial for survival. Aversive memories can, however, become counter-adaptive when they are overly generalized to harmless cues and contexts. In a fruit fly odor-electric shock associative memory paradigm, we found that learned avoidance lost its specificity for the trained odor and became general to novel odors within a day of training. We discuss the possible neural circuit mechanisms of this effect and highlight the parallelism to over-generalization of learned fear behavior after an incubation period in rodents and humans, with due relevance for post-traumatic stress disorder. © 2017. Published by The Company of Biologists Ltd.

  14. Effects on interpersonal memory of dancing in time with others

    OpenAIRE

    Matthew Harold Woolhouse; Dan eTidhar; Ian eCross

    2016-01-01

    We report an experiment investigating whether dancing to the same music enhances recall of person-related memory targets. The experiment used 40 dancers (all of whom were unaware of the experiment’s aim), 2-channel silent-disco radio headphones, a marked-up dance floor, two types of music, and memory targets (sash colours and symbols). In each trial, 10 dancers wore radio headphones and one of 4 different coloured sashes, half of which carried cat symbols. Using silent-disco technology, one t...

  15. Why are You Late?: Investigating the Role of Time Management in Time-Based Prospective Memory

    Science.gov (United States)

    Waldum, Emily R; McDaniel, Mark A.

    2016-01-01

    Time-based prospective memory tasks (TBPM) are those that are to be performed at a specific future time. Contrary to typical laboratory TBPM tasks (e.g., “hit the “z” key every 5 minutes”), many real-world TBPM tasks require more complex time-management processes. For instance to attend an appointment on time, one must estimate the duration of the drive to the appointment and then utilize this estimate to create and execute a secondary TBPM intention (e.g., “I need to start driving by 1:30 to make my 2:00 appointment on time”). Future under- and overestimates of drive time can lead to inefficient TBPM performance with the former lending to missed appointments and the latter to long stints in the waiting room. Despite the common occurrence of complex TBPM tasks in everyday life, to date, no studies have investigated how components of time management, including time estimation, affect behavior in such complex TBPM tasks. Therefore, the current study aimed to investigate timing biases in both older and younger adults and further to determine how such biases along with additional time management components including planning and plan fidelity influence complex TBPM performance. Results suggest for the first time that younger and older adults do not always utilize similar timing strategies, and as a result, can produce differential timing biases under the exact same environmental conditions. These timing biases, in turn, play a vital role in how efficiently both younger and older adults perform a later TBPM task that requires them to utilize their earlier time estimate. PMID:27336325

  16. Analysis of Time n Frequency EEG Feature Extraction Methods for Mental Task Classification

    Directory of Open Access Journals (Sweden)

    Caglar Uyulan

    2017-01-01

    Full Text Available Many endogenous and external components may affect the physiological, mental and behavioral states in humans. Monitoring tools are required to evaluate biomarkers, identify biological events, and predict their outcomes. Being one of the valuable indicators, brain biomarkers derived from temporal or spectral electroencephalography (EEG signals processing, allow for the classification of mental disorders and mental tasks. An EEG signal has a nonstationary nature and individual frequency feature, hence it can be concluded that each subject has peculiar timing and data to extract unique features. In order to classify data, which are collected by performing four mental task (reciting the alphabet backwards, imagination of rotation of a cube, imagination of right hand movements (open/close and performing mathematical operations, discriminative features were extracted using four competitive time-frequency techniques; Wavelet Packet Decomposition (WPD, Morlet Wavelet Transform (MWT, Short Time Fourier Transform (STFT and Wavelet Filter Bank (WFB, respectively. The extracted features using both time and frequency domain information were then reduced using a principal component analysis for subset reduction. Finally, the reduced subsets were fed into a multi-layer perceptron neural network (MP-NN trained with back propagation (BP algorithm to generate a predictive model. This study mainly focuses on comparing the relative performance of time-frequency feature extraction methods that are used to classify mental tasks. The real-time (RT conducted experimental results underlined that the WPD feature extraction method outperforms with 92% classification accuracy compared to three other aforementioned methods for four different mental tasks.

  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. Effects on interpersonal memory of dancing in time with others

    Directory of Open Access Journals (Sweden)

    Matthew Harold Woolhouse

    2016-02-01

    Full Text Available We report an experiment investigating whether dancing to the same music enhances recall of person-related memory targets. The experiment used 40 dancers (all of whom were unaware of the experiment’s aim, 2-channel silent-disco radio headphones, a marked-up dance floor, two types of music, and memory targets (sash colours and symbols. In each trial, 10 dancers wore radio headphones and one of 4 different coloured sashes, half of which carried cat symbols. Using silent-disco technology, one type of music was surreptitiously transmitted to half the dancers, while music at a different tempo was transmitted to the remaining dancers. Pre-experiment, the dancers’ faces were photographed. Post-experiment, each dancer was presented with the photographs of the other dancers and asked to recall their memory targets. Results showed that same-music dancing significantly enhanced memory for sash colour and sash symbol. Our findings are discussed in light of recent eye-movement research that showed significantly increased gaze durations for people observing music-dance synchrony versus music-dance asynchrony, and in relation to current literature on interpersonal entrainment, group cohesion and social bonding.

  19. Binding across space and time in visual working memory.

    Science.gov (United States)

    Karlsen, Paul Johan; Allen, Richard J; Baddeley, Alan D; Hitch, Graham J

    2010-04-01

    Recent studies of visual short-term memory have suggested that the binding of features such as color and shape into remembered objects is relatively automatic. A series of seven experiments broadened this investigation by comparing the immediate retention of colored shapes with performance when color and shape were separated either spatially or temporally, with participants required actively to form the bound object. Attentional load was manipulated with a demanding concurrent task, and retention in working memory was then tested using a single recognition probe. Both spatial and temporal separation of features tended to impair performance, as did the concurrent task. There was, however, no evidence for greater attentional disruption of performance as a result of either spatial or temporal separation of features. Implications for the process of binding in visual working memory are discussed, and an interpretation is offered in terms of the episodic buffer component of working memory, which is assumed to be a passive store capable of holding bound objects, but not of performing the binding.

  20. Bidirectional Interference between Timing and Concurrent Memory Processing in Children

    Science.gov (United States)

    Rattat, Anne-Claire

    2010-01-01

    This study investigated the nature of resources involved in duration processing in 5- and 8-year-olds. The children were asked to reproduce the duration of a visual or auditory stimulus. They performed this task either alone or concurrently with an executive task (Experiment 1) or with a digit or visuospatial memory task (Experiment 2). The…

  1. Time Searching for Similar Binary Vectors in Associative Memory

    Czech Academy of Sciences Publication Activity Database

    Frolov, A. A.; Húsek, Dušan; Rachkovskij, D.

    2006-01-01

    Roč. 42, č. 5 (2006), s. 615-623 ISSN 1060-0396 R&D Projects: GA MŠk(CZ) 1M0567 Institutional research plan: CEZ:AV0Z10300504 Keywords : associative memory * neural network * Hopfield network * binary vector * indexing * hashing Subject RIV: BB - Applied Statistics, Operational Research

  2. The memory during prison time: in between massification and resistance

    Directory of Open Access Journals (Sweden)

    José Mauro Oliveira Braz

    2016-04-01

    Full Text Available This article aims to understand how the penitentiary institution can, through its dynamics, experiences and disciplinary practices, enable the balance of subjective differences from jailed people by the assimilation of living standards in terms of submission and obedience to the culture prison. As for the methodology used, the literature that aided the construction of this discussion and directed this work came from authors such as Foucault, Goffman, Thompson and Althusser directed such work. The phenomenon of “subjective massification” is present to the extent where institutions act in order to produce similar experiences in prison, turning them into traces of memories and souvenirs. Thus, the prison, like any other place of memory, conducts its incarcerated subjects according to a set of determinations established for the transmission of discipline and control. But the prison environment that acts in the pursuit of subjective standardization is based on contradictions and forces of correlations that also give way to resistance. Configuring, in that way, not only the preservation of the memory from that selected space, but also the production arrangements, or even better, a memory modality in terms of possible circumstances that require the power of the institution.

  3. Access time optimization of SRAM memory with statistical yield constraint

    NARCIS (Netherlands)

    Doorn, T.S.; Maten, ter E.J.W.; Di Bucchianico, A.; Beelen, T.G.J.; Janssen, H.H.J.M.

    2012-01-01

    A product may fail when design parameters are subject to large deviations. To guarantee yield one likes to determine bounds on the parameter range such that the fail probability P_fail is small. For Static Random Access Memory (SRAM) characteristics like Static Noise Margin and Read Current,

  4. Different contexts, different effects? Work time and mental health in the United States and Germany.

    Science.gov (United States)

    Kleiner, Sibyl; Schunck, Reinhard; Schömann, Klaus

    2015-03-01

    This paper takes a comparative approach to the topic of work time and health, asking whether weekly work hours matter for mental health. We hypothesize that these relationships differ within the United States and Germany, given the more regulated work time environments within Germany and the greater incentives to work long hours in the United States. We further hypothesize that German women will experience greatest penalties to long hours. We use data from the German Socioeconomic Panel and the National Longitudinal Survey of Youth to examine hours effects on mental health score at midlife. The results support our initial hypothesis. In Germany, longer work time is associated with worse mental health, while in the United States, as seen in previous research, the associations are more complex. Our results do not show greater mental health penalties for German women and suggest instead a selection effect into work hours operating by gender. © American Sociological Association 2015.

  5. 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…

  6. Working Memory Span Development: A Time-Based Resource-Sharing Model Account

    Science.gov (United States)

    Barrouillet, Pierre; Gavens, Nathalie; Vergauwe, Evie; Gaillard, Vinciane; Camos, Valerie

    2009-01-01

    The time-based resource-sharing model (P. Barrouillet, S. Bernardin, & V. Camos, 2004) assumes that during complex working memory span tasks, attention is frequently and surreptitiously switched from processing to reactivate decaying memory traces before their complete loss. Three experiments involving children from 5 to 14 years of age…

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

    Science.gov (United States)

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

    2016-01-01

    This research investigated whether episodic memory development can be explained by improvements in relational binding processes, involved in forming novel associations between events and the context in which they occurred. Memory for item-space, item-time, and item-item relations was assessed in an ethnically diverse sample of 151 children aged…

  8. Improving performance of single-path code through a time-predictable memory hierarchy

    DEFF Research Database (Denmark)

    Cilku, Bekim; Puffitsch, Wolfgang; Prokesch, Daniel

    2017-01-01

    -predictable memory hierarchy with a prefetcher that exploits the predictability of execution traces in single-path code to speed up code execution. The new memory hierarchy reduces both the cache-miss penalty time and the cache-miss rate on the instruction cache. The benefit of the approach is demonstrated through...

  9. Wait times in the emergency department for patients with mental illness

    Science.gov (United States)

    Atzema, Clare L.; Schull, Michael J.; Kurdyak, Paul; Menezes, Natasja M.; Wilton, Andrew S.; Vermuelen, Marian J.; Austin, Peter C.

    2012-01-01

    Background: It has been suggested that patients with mental illness wait longer for care than other patients in the emergency department. We determined wait times for patients with and without mental health diagnoses during crowded and noncrowded periods in the emergency department. Methods: We conducted a population-based retrospective cohort analysis of adults seen in 155 emergency departments in Ontario between April 2007 and March 2009. We compared wait times and triage scores for patients with mental illness to those for all other patients who presented to the emergency department during the study period. Results: The patients with mental illness (n = 51 381) received higher priority triage scores than other patients, regardless of crowding. The time to assessment by a physician was longer overall for patients with mental illness than for other patients (median 82, interquartile range [IQR] 41–147 min v. median 75 [IQR 36–140] min; p < 0.001). The median time from the decision to admit the patient to hospital to ward transfer was markedly shorter for patients with mental illness than for other patients (median 74 [IQR 15–215] min v. median 152 [IQR 45–605] min; p < 0.001). After adjustment for other variables, patients with mental illness waited 10 minutes longer to see a physician compared with other patients during noncrowded periods (95% confidence interval [CI] 8 to 11), but they waited significantly less time than other patients as crowding increased (mild crowding: −14 [95% CI −12 to −15] min; moderate crowding: −38 [95% CI −35 to −42] min; severe crowding: −48 [95% CI −39 to −56] min; p < 0.001). Interpretation: Patients with mental illness were triaged appropriately in Ontario’s emergency departments. These patients waited less time than other patients to see a physician under crowded conditions and only slightly longer under noncrowded conditions. PMID:23148052

  10. Psychometric evaluation of the internalized stigma of mental illness scale for patients with mental illnesses: measurement invariance across time.

    Directory of Open Access Journals (Sweden)

    Chih-Cheng Chang

    Full Text Available BACKGROUND: The current investigation examined the psychometric properties of the Internalized Stigma of Mental Illness (ISMI scale in a sample of patients with mental illness. In addition to the internal consistency, test-retest reliability, and concurrent validity that previous studies have tested for the ISMI, we extended the evaluation to its construct validity and measurement invariance using confirmatory factor analysis (CFA. METHODS: Three hundred forty-seven participants completed two questionnaires (i.e., the ISMI and the Depression and Somatic Symptoms Scale [DSSS], and 162 filled out the ISMI again after 50.23±31.18 days. RESULTS: The results of this study confirmed the frame structure of the ISMI; however, the Stigma Resistance subscale in the ISMI seemed weak. In addition, internal consistency, test-retest reliability, and concurrent validity were all satisfactory for all subscales and the total score of the ISMI, except for Stigma Resistance (α = 0.66; ICC = 0.52, and r = 0.02 to 0.06 with DSSS. Therefore, we hypothesize that Stigma Resistance is a new concept rather than a concept in internalized stigma. The acceptable fit indices supported the measurement invariance of the ISMI across time, and suggested that people with mental illness interpret the ISMI items the same at different times. CONCLUSION: The clinical implication of our finding is that clinicians, when they design interventions, may want to use the valid and reliable ISMI without the Stigma Resistance subscale to evaluate the internalized stigma of people with mental illness.

  11. Stress in the zoo: Tracking the impact of stress on memory formation over time.

    Science.gov (United States)

    Vogel, Susanne; Schwabe, Lars

    2016-09-01

    Although stress is well known to modulate human memory, precisely how memory formation is altered by a stressful encounter remains unclear. Stress effects on cognition are mainly mediated by the rapidly acting sympathetic nervous system, resulting in the release of catecholamines, and the slower acting hypothalamus-pituitary-adrenal axis secreting cortisol, which induces its effects on cognition through fast, non-genomic actions and delayed, genomic actions. Importantly, these different waves of the physiological stress response are thought to dynamically alter neural processing in brain regions important for memory such as the amygdala and the hippocampus. However, the precise time course of stress effects on memory formation is still unclear. To track the development of stress effects on memory over time, we tested individuals who underwent a stressful experience or a control procedure before a 2-h walk through a zoo, while an automatic camera continuously photographed the events they encoded. In a recognition memory test one week later, participants were presented with target photographs of their own zoo tour and lure photographs from an alternate tour. Stressed participants showed better memory for the experimental treatment than control participants, and this memory enhancement for the stressful encounter itself was directly linked to the sympathetic stress response. Moreover, stress enhanced memory for events encoded 41-65min after stressor onset, which was associated with the cortisol stress response, most likely arising from non-genomic cortisol actions. However, memory for events encoded long after the stressor, when genomic cortisol actions had most likely developed, remained unchanged. Our findings provide novel insights into how stress effects on memory formation develop over time, depending on the activity of major physiological stress response systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Mood-congruent false memories persist over time.

    Science.gov (United States)

    Knott, Lauren M; Thorley, Craig

    2014-01-01

    In this study, we examined the role of mood-congruency and retention interval on the false recognition of emotion laden items using the Deese/Roediger-McDermott (DRM) paradigm. Previous research has shown a mood-congruent false memory enhancement during immediate recognition tasks. The present study examined the persistence of this effect following a one-week delay. Participants were placed in a negative or neutral mood, presented with negative-emotion and neutral-emotion DRM word lists, and administered with both immediate and delayed recognition tests. Results showed that a negative mood state increased remember judgments for negative-emotion critical lures, in comparison to neutral-emotion critical lures, on both immediate and delayed testing. These findings are discussed in relation to theories of spreading activation and emotion-enhanced memory, with consideration of the applied forensic implications of such findings.

  13. The impact of tuition fees amount on mental health over time in British students.

    Science.gov (United States)

    Richardson, T; Elliott, P; Roberts, R

    2015-09-01

    Previous studies have shown a relationship between debt and mental health problems in students. This study aimed to examine the effect of differences in tuition fees amount on changes in mental health over time. A prospective cohort study followed 390 first-year British students who differed on their tuition fees level at 4 time points across their first 2 years at university. Participants completed measures of global mental health, depression, anxiety, stress, alcohol-related problems at up to four time points in their first two years at university. Mixed-factorial ANOVAs were used to assess the impact of tuition fees amount on changes in scores over time. There was no difference based on fees at Time 1 for anxiety, stress, depression and global mental health. At Time 2, those charged £0-2.9k or £3-4k improved while those charged £8-9k stayed the same. However, this trend reversed by Times 3 and 4. Undergraduates mental health is partially affected by the level of tuition fees; however, the recent increase in tuition fees does not appear to have had a lasting impact at present. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Autobiographical Memory Retrieval and Hippocampal Activation as a Function of Repetition and the Passage of Time

    Directory of Open Access Journals (Sweden)

    Lynn Nadel

    2007-01-01

    Full Text Available Multiple trace theory (MTT predicts that hippocampal memory traces expand and strengthen as a function of repeated memory retrievals. We tested this hypothesis utilizing fMRI, comparing the effect of memory retrieval versus the mere passage of time on hippocampal activation. While undergoing fMRI scanning, participants retrieved remote autobiographical memories that had been previously retrieved either one month earlier, two days earlier, or multiple times during the preceding month. Behavioral analyses revealed that the number and consistency of memory details retrieved increased with multiple retrievals but not with the passage of time. While all three retrieval conditions activated a similar set of brain regions normally associated with autobiographical memory retrieval including medial temporal lobe structures, hippocampal activation did not change as a function of either multiple retrievals or the passage of time. However, activation in other brain regions, including the precuneus, lateral prefrontal cortex, parietal cortex, lateral temporal lobe, and perirhinal cortex increased after multiple retrievals, but was not influenced by the passage of time. These results have important implications for existing theories of long-term memory consolidation.

  15. Cardiorespiratory Dynamic Response to Mental Stress: A Multivariate Time-Frequency Analysis

    Directory of Open Access Journals (Sweden)

    Devy Widjaja

    2013-01-01

    out continuously in time to evaluate the dynamic response to mental stress and attention. The results show an increased heart and respiratory rate during stress and attention, compared to a resting condition. Also a fast reduction in vagal activity is noted. The partial TF analysis reveals a faster reduction of RRV power related to (3 s than unrelated to (30 s respiration, demonstrating that the autonomic response to mental stress is driven by mechanisms characterized by different temporal scales.

  16. Mental Toughness Moderates Social Loafing in Cycle Time-Trial Performance

    Science.gov (United States)

    Haugen, Tommy; Reinboth, Michael; Hetlelid, Ken J.; Peters, Derek M.; Høigaard, Rune

    2016-01-01

    Purpose: The purpose of this study was to determine if mental toughness moderated the occurrence of social loafing in cycle time-trial performance. Method: Twenty-seven men (M[subscript age] = 17.7 years, SD = 0.6) completed the Sport Mental Toughness Questionnaire prior to completing a 1-min cycling trial under 2 conditions: once with individual…

  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 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. Short-term memory loss over time without retroactive stimulus interference.

    Science.gov (United States)

    Cowan, Nelson; AuBuchon, Angela M

    2008-02-01

    A key question in cognitive psychology is whether information in short-term memory is lost as a function of time. Lewandowsky, Duncan, and Brown (2004) argued against that memory loss because forgetting in serial recall occurred to the same extent across serial positions regardless of the rate of recall. However, we believe Lewandowsky et al. (2004) only prevented one of two types of rehearsal; they did not prevent nonarticulatory rehearsal via attention. To prevent articulatory and nonarticulatory rehearsal without introducing interference, we presented unevenly timed stimuli for serial recall and, on some trials, required that the timing of stimuli be reproduced in the response. In those trials only, evidence of memory loss over time emerged. Further research is needed to identify whether this memory loss is decay or lost distinctiveness.

  19. The effect of part-time sick leave for employees with mental disorders

    DEFF Research Database (Denmark)

    Høgelund, Jan; Holm, Anders

    reduces the duration until employees with mental disorders end their sick leave by reporting ready for returning to regular working hours. The programme allows fully sick-listed employees to resume work at reduced hours. When the sick-listed employee’s health improves, working hours are increased until...... the employee is able to work regular hours. We use combined survey and register data about 226 long-term sick-listed employees with mental disorders and 638 employees with physical disorders. Our analyses show that part-time sick-listing significantly reduces the duration until returning to regular working...... hours for employees with physical disorders. In contrast, we find that part-time sick-listing does not reduce durations for employees with mental disorders. The analyses also illustrate the importance of adjusting for unobserved differences between part-time sick-listed and full-time sick...

  20. Mood-congruent false memories persist over time

    OpenAIRE

    Knott, L.; Thorley, C.

    2014-01-01

    In this study we examined the role of mood-congruency and retention interval on the false recognition of emotion laden items using the Deese/Roediger-McDermott (DRM) paradigm. Previous research has shown a mood-congruent false memory enhancement during immediate recognition tasks. The present study examined the persistence of this effect following a one-week delay. Participants were placed in a negative or neutral mood, presented with negative-emotion and neutral-emotion DRM word lists, and a...

  1. Effect of time span and task load on pilot mental workload

    Science.gov (United States)

    Berg, S. L.; Sheridan, T. B.

    1986-01-01

    Two sets of simulations designed to examine how a pilot's mental workload is affected by continuous manual-control activity versus discrete mental tasks that included the length of time between receiving an assignment and executing it are described. The first experiment evaluated two types of measures: objective performance indicators and subjective ratings. Subjective ratings for the two missions were different, but the objective performance measures were similar. In the second experiments, workload levels were increased and a second performance measure was taken. Mental workload had no influence on either performance-based workload measure. Subjective ratings discriminated among the scenarios and correlated with performance measures for high-workload flights. The number of mental tasks performed did not influence error rates, although high manual workloads did increase errors.

  2. Connectivity, prison environment and mental health among first-time male inmates in Mexico City.

    Science.gov (United States)

    Albertie, Ariel; Bourey, Christine; Stephenson, Rob; Bautista-Arredondo, Sergio

    2017-02-01

    Research from high-income countries suggests that prison populations are affected disproportionately by mental illness. However, little research has examined mental health among prisoners in low- and middle-income countries or associations between mental health and contextual factors surrounding the prison experience among susceptible first-time inmates in these settings. The current study examines associations between connectivity, prison environment and mental health (major depression and substance use) among novice male inmates (n = 593) in three Mexico City prisons. Severe depression (46.2%), any substance use (53.8%) and heavy substance use (45.7%) were prevalent. Among key co-variates, recent visitors were protective for severe depression, conjugal visits for any substance use and prison employment for heavy substance use. Physical attacks were associated with increased prevalence of depression, sentence time served with both any and heavy substance use and overcrowding with any substance use. These findings suggest the need for routine health assessments to improve identification and treatment programmes to minimise mental health burden. Addressing demographic risk factors as well as contextual determinants, by decreasing physical violence and overcrowding and supporting outside connections for prisoners, may help improve inmate mental health.

  3. 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

  4. 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.

  5. Internalizing versus Externalizing Control: Different Ways to Perform a Time-Based Prospective Memory Task

    Science.gov (United States)

    Huang, Tracy; Loft, Shayne; Humphreys, Michael S.

    2014-01-01

    "Time-based prospective memory" (PM) refers to performing intended actions at a future time. Participants with time-based PM tasks can be slower to perform ongoing tasks (costs) than participants without PM tasks because internal control is required to maintain the PM intention or to make prospective-timing estimates. However, external…

  6. Experimental Investigation of the Time Course Effects of Acute Exercise on False Episodic Memory

    Directory of Open Access Journals (Sweden)

    Ali Siddiqui

    2018-06-01

    Full Text Available Previous experimental work suggests that acute exercise may positively influence the accurate recall of past episodic events. However, few studies have examined whether acute exercise also reduces the number of false episodic memories. We evaluated this paradigm in conjunction with an examination of the temporal effects of acute exercise, which have previously been shown to play an important role in subserving episodic memory function. Twenty young adults participated in three experimental visits, including a non-exercise control visit, a visit involving an acute bout (20 min of moderate-intensity exercise occurring prior to the memory task, and a visit involving an acute bout of exercise occurring during the encoding of the memory task. All visits were counterbalanced and occurred at least 24 h apart. The Deese–Roediger–McDermott (DRM Paradigm, involving a separate word list trial for each visit, was employed to assess accurate and false episodic memory recall. For each visit, a short-term (immediate recall and a long-term (25-min delay memory recall was assessed. For both time points, the visit that involved exercise prior to encoding resulted in better short-term and long-term memory function (F(2 = 11.56, p < 0.001, η2p = 0.38. For both time points, the control visit resulted in a greater number of false memories. These findings suggest that acute moderate-intensity exercise may help to increase the accurate recall of past episodic memories and may help to reduce the rate of false memories.

  7. Disambiguating past events: Accurate source memory for time and context depends on different retrieval processes.

    Science.gov (United States)

    Persson, Bjorn M; Ainge, James A; O'Connor, Akira R

    2016-07-01

    Current animal models of episodic memory are usually based on demonstrating integrated memory for what happened, where it happened, and when an event took place. These models aim to capture the testable features of the definition of human episodic memory which stresses the temporal component of the memory as a unique piece of source information that allows us to disambiguate one memory from another. Recently though, it has been suggested that a more accurate model of human episodic memory would include contextual rather than temporal source information, as humans' memory for time is relatively poor. Here, two experiments were carried out investigating human memory for temporal and contextual source information, along with the underlying dual process retrieval processes, using an immersive virtual environment paired with a 'Remember-Know' memory task. Experiment 1 (n=28) showed that contextual information could only be retrieved accurately using recollection, while temporal information could be retrieved using either recollection or familiarity. Experiment 2 (n=24), which used a more difficult task, resulting in reduced item recognition rates and therefore less potential for contamination by ceiling effects, replicated the pattern of results from Experiment 1. Dual process theory predicts that it should only be possible to retrieve source context from an event using recollection, and our results are consistent with this prediction. That temporal information can be retrieved using familiarity alone suggests that it may be incorrect to view temporal context as analogous to other typically used source contexts. This latter finding supports the alternative proposal that time since presentation may simply be reflected in the strength of memory trace at retrieval - a measure ideally suited to trace strength interrogation using familiarity, as is typically conceptualised within the dual process framework. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. 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.

  9. Time-limited effects of emotional arousal on item and source memory.

    Science.gov (United States)

    Wang, Bo; Sun, Bukuan

    2015-01-01

    Two experiments investigated the time-limited effects of emotional arousal on consolidation of item and source memory. In Experiment 1, participants memorized words (items) and the corresponding speakers (sources) and then took an immediate free recall test. Then they watched a neutral, positive, or negative video 5, 35, or 50 min after learning, and 24 hours later they took surprise memory tests. Experiment 2 was similar to Experiment 1 except that (a) a reality monitoring task was used; (b) elicitation delays of 5, 30, and 45 min were used; and (c) delayed memory tests were given 60 min after learning. Both experiments showed that, regardless of elicitation delay, emotional arousal did not enhance item recall memory. Second, both experiments showed that negative arousal enhanced delayed item recognition memory only at the medium elicitation delay, but not in the shorter or longer delays. Positive arousal enhanced performance only in Experiment 1. Third, regardless of elicitation delay, emotional arousal had little effect on source memory. These findings have implications for theories of emotion and memory, suggesting that emotion effects are contingent upon the nature of the memory task and elicitation delay.

  10. Training patients in Time Pressure Management, a cognitive strategy for mental slowness

    NARCIS (Netherlands)

    Winkens, I.; Heugten, C.M. van; Wade, D.T.; Fasotti, L.

    2009-01-01

    Purpose: To provide clinical practitioners with a framework for teaching patients Time Pressure Management, a cognitive strategy that aims to reduce disabilities arising from mental slowness due to acquired brain injury. Time Pressure Management provides patients with compensatory strategies to deal

  11. Effects of electronic emergency-department whiteboards on clinicians' time distribution and mental workload

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2016-01-01

    Whiteboards are a central tool at emergency departments. We investigate how the substitution of electronic for dry-erase whiteboards affects emergency department clinicians’ mental workload and distribution of their time. With the electronic whiteboard, physicians and nurses spend more...... of their time in the work areas where other clinicians are present and whiteboard information is permanently displayed, and less in the patient rooms. Main reasons for these changes appear to be that the electronic whiteboard facilitates better timeouts and handovers. Physicians and nurses are, however......, in the patient rooms for longer periods at a time, suggesting a more focused patient contact. The physicians’ mental workload has increased during timeouts, whereas the nurses’ mental workload has decreased at the start of shifts when they form an overview of the emergency department. Finally, the secretaries...

  12. 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 ...

  13. Tracking the Time-Dependent Role of the Hippocampus in Memory Recall Using DREADDs.

    Science.gov (United States)

    Varela, Carmen; Weiss, Sarah; Meyer, Retsina; Halassa, Michael; Biedenkapp, Joseph; Wilson, Matthew A; Goosens, Ki Ann; Bendor, Daniel

    2016-01-01

    The hippocampus is critical for the storage of new autobiographical experiences as memories. Following an initial encoding stage in the hippocampus, memories undergo a process of systems-level consolidation, which leads to greater stability through time and an increased reliance on neocortical areas for retrieval. The extent to which the retrieval of these consolidated memories still requires the hippocampus is unclear, as both spared and severely degraded remote memory recall have been reported following post-training hippocampal lesions. One difficulty in definitively addressing the role of the hippocampus in remote memory retrieval is the precision with which the entire volume of the hippocampal region can be inactivated. To address this issue, we used Designer Receptors Exclusively Activated by Designer Drugs (DREADDs), a chemical-genetic tool capable of highly specific neuronal manipulation over large volumes of brain tissue. We find that remote (>7 weeks after acquisition), but not recent (1-2 days after acquisition) contextual fear memories can be recalled after injection of the DREADD agonist (CNO) in animals expressing the inhibitory DREADD in the entire hippocampus. Our data demonstrate a time-dependent role of the hippocampus in memory retrieval, supporting the standard model of systems consolidation.

  14. Ageing and feature binding in visual working memory: The role of presentation time.

    Science.gov (United States)

    Rhodes, Stephen; Parra, Mario A; Logie, Robert H

    2016-01-01

    A large body of research has clearly demonstrated that healthy ageing is accompanied by an associative memory deficit. Older adults exhibit disproportionately poor performance on memory tasks requiring the retention of associations between items (e.g., pairs of unrelated words). In contrast to this robust deficit, older adults' ability to form and temporarily hold bound representations of an object's surface features, such as colour and shape, appears to be relatively well preserved. However, the findings of one set of experiments suggest that older adults may struggle to form temporary bound representations in visual working memory when given more time to study objects. However, these findings were based on between-participant comparisons across experimental paradigms. The present study directly assesses the role of presentation time in the ability of younger and older adults to bind shape and colour in visual working memory using a within-participant design. We report new evidence that giving older adults longer to study memory objects does not differentially affect their immediate memory for feature combinations relative to individual features. This is in line with a growing body of research suggesting that there is no age-related impairment in immediate memory for colour-shape binding.

  15. Time Frame Affects Vantage Point in Episodic and Semantic Autobiographical Memory: Evidence from Response Latencies

    Directory of Open Access Journals (Sweden)

    Jerzy J. Karylowski

    2017-04-01

    Full Text Available Previous research suggests that, with the passage of time, representations of self in episodic memory become less dependent on their initial (internal vantage point and shift toward an external perspective that is normally characteristic of how other people are represented. The present experiment examined this phenomenon in both episodic and semantic autobiographical memory using latency of self-judgments as a measure of accessibility of the internal vs. the external perspective. Results confirmed that in the case of representations of the self retrieved from recent autobiographical memories, trait-judgments regarding unobservable self-aspects (internal perspective were faster than trait judgments regarding observable self-aspects (external perspective. Yet, in the case of self-representations retrieved from memories of a more distant past, judgments regarding observable self-aspects were faster. Those results occurred for both self-representations retrieved from episodic memory and for representations retrieved from the semantic memory. In addition, regardless of the effect of time, greater accessibility of unobservable (vs. observable self-aspects was associated with the episodic rather than semantic autobiographical memory. Those results were modified by neither declared trait’s self-descriptiveness (yes vs. no responses nor by its desirability (highly desirable vs. moderately desirable traits. Implications for compatibility between how self and others are represented and for the role of self in social perception are discussed.

  16. Time Frame Affects Vantage Point in Episodic and Semantic Autobiographical Memory: Evidence from Response Latencies.

    Science.gov (United States)

    Karylowski, Jerzy J; Mrozinski, Blazej

    2017-01-01

    Previous research suggests that, with the passage of time, representations of self in episodic memory become less dependent on their initial (internal) vantage point and shift toward an external perspective that is normally characteristic of how other people are represented. The present experiment examined this phenomenon in both episodic and semantic autobiographical memory using latency of self-judgments as a measure of accessibility of the internal vs. the external perspective. Results confirmed that in the case of representations of the self retrieved from recent autobiographical memories, trait-judgments regarding unobservable self-aspects (internal perspective) were faster than trait judgments regarding observable self-aspects (external perspective). Yet, in the case of self-representations retrieved from memories of a more distant past, judgments regarding observable self-aspects were faster. Those results occurred for both self-representations retrieved from episodic memory and for representations retrieved from the semantic memory. In addition, regardless of the effect of time, greater accessibility of unobservable (vs. observable) self-aspects was associated with the episodic rather than semantic autobiographical memory. Those results were modified by neither declared trait's self-descriptiveness ( yes vs. no responses) nor by its desirability (highly desirable vs. moderately desirable traits). Implications for compatibility between how self and others are represented and for the role of self in social perception are discussed.

  17. Write/erase time of nanoseconds in quantum dot based memory structures

    International Nuclear Information System (INIS)

    Nowozin, Tobias; Marent, Andreas; Geller, Martin; Bimberg, Dieter

    2008-01-01

    We have developed a novel charge-storage memory concept based on III-V semiconductor quantum dots (QDs) which has a number of fundamental advantages over conventional Si/SiO 2 floating gate memories (Flash): material-tunable and voltage-tunable barriers for improved intrinsic speed and/or storage time and high endurance. To investigate the potential of this new memory concept we have determined intrinsic write/erase times in memory structures based on InAs/GaAs and GaSb/GaAs QDs using capacitance-voltage spectroscopy. We measured a write time below 15 ns independent of the localization energy (i.e. the storage time) of the QDs. This write time is more than three orders of magnitude faster than in a Flash cell and already below the write time of a dynamic random access memory (DRAM). The erase time was determined to be 42 ns for InAs/GaAs QDs and 1.5 ms for GaSb/GaAs QDs for applied electric fields of 166 kV/cm and 206 kV/cm, respectively. From these results we derive an erase time of 1 ns in GaSb QDs for an electric field of 330 kV/cm

  18. Preliminary study of visual perspective in mental time travel in schizophrenia.

    Science.gov (United States)

    Wang, Ya; Wang, Yi; Zhao, Qing; Cui, Ji-Fang; Hong, Xiao-Hong; Chan, Raymond Ck

    2017-10-01

    This study explored specificity and visual perspective of mental time travel in schizophrenia. Fifteen patients with schizophrenia and 18 controls were recruited. Participants were asked to recall or imagine specific events according to cue words. Results showed that schizophrenia patients generated fewer specific events than controls, the recalled events were more specific than imagined events. Schizophrenia adopted less field perspective and more observer perspective than controls. These results suggested that patients with schizophrenia were impaired in mental time travel both in specificity and visual perspective. Further studies are needed to identify the underlying mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Mental time travel to the future might be reduced in sleep.

    Science.gov (United States)

    Speth, Jana; Schloerscheidt, Astrid M; Speth, Clemens

    2017-02-01

    We present a quantitative study of mental time travel to the future in sleep. Three independent, blind judges analysed a total of 563 physiology-monitored mentation reports from sleep onset, REM sleep, non-REM sleep, and waking. The linguistic tool for the mentation report analysis is based on established grammatical and cognitive-semantic theories and has been validated in previous studies. Our data indicate that REM and non-REM sleep must be characterized by a reduction in mental time travel to the future, which would support earlier physiological evidence at the level of brain function. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. 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

  1. 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…

  2. Estimation and Application of Ecological Memory Functions in Time and Space

    Science.gov (United States)

    Itter, M.; Finley, A. O.; Dawson, A.

    2017-12-01

    A common goal in quantitative ecology is the estimation or prediction of ecological processes as a function of explanatory variables (or covariates). Frequently, the ecological process of interest and associated covariates vary in time, space, or both. Theory indicates many ecological processes exhibit memory to local, past conditions. Despite such theoretical understanding, few methods exist to integrate observations from the recent past or within a local neighborhood as drivers of these processes. We build upon recent methodological advances in ecology and spatial statistics to develop a Bayesian hierarchical framework to estimate so-called ecological memory functions; that is, weight-generating functions that specify the relative importance of local, past covariate observations to ecological processes. Memory functions are estimated using a set of basis functions in time and/or space, allowing for flexible ecological memory based on a reduced set of parameters. Ecological memory functions are entirely data driven under the Bayesian hierarchical framework—no a priori assumptions are made regarding functional forms. Memory function uncertainty follows directly from posterior distributions for model parameters allowing for tractable propagation of error to predictions of ecological processes. We apply the model framework to simulated spatio-temporal datasets generated using memory functions of varying complexity. The framework is also applied to estimate the ecological memory of annual boreal forest growth to local, past water availability. Consistent with ecological understanding of boreal forest growth dynamics, memory to past water availability peaks in the year previous to growth and slowly decays to zero in five to eight years. The Bayesian hierarchical framework has applicability to a broad range of ecosystems and processes allowing for increased understanding of ecosystem responses to local and past conditions and improved prediction of ecological

  3. Time Keeping and Working Memory Development in Early Adolescence: A 4-Year Follow-Up

    Science.gov (United States)

    Forman, Helen; Mantyla, Timo; Carelli, Maria G.

    2011-01-01

    In this longitudinal study, we examined time keeping in relation to working memory (WM) development. School-aged children completed two tasks of WM updating and a time monitoring task in which they indicated the passing of time every 5 min while watching a film. Children completed these tasks first when they were 8 to 12 years old and then 4 years…

  4. Short-Term Memory Loss Over Time Without Retroactive Stimulus Interference

    OpenAIRE

    Cowan, Nelson; AuBuchon, Angela M.

    2008-01-01

    A key question in cognitive psychology is whether information in short-term memory is lost as a function of time. Lewandowsky, Duncan, and Brown (2004) argued against that memory loss because forgetting in serial recall occurred to the same extent across serial positions regardless of the rate of recall. However, we believe Lewandowsky et al. only prevented one of two types of rehearsal; they did not prevent non-articulatory rehearsal via attention. To prevent articulatory and non-articulator...

  5. Picosecond time measurement using ultra fast analog memories

    OpenAIRE

    Breton, D.; Delagnes, E.; Maalmi, J.

    2009-01-01

    International audience; The currently existing electronics dedicated to precise time measurement is mainly based on the use of constant fraction discriminators (CFD) associated with Time to Digital Converters (TDC). The constant fraction technique minimizes the time walk effect (dependency of timing on the pulse amplitude). Several attempts have been made to integrate CFD in multi-channel ASICs. But the time resolution measured on the most advanced one is of the order of 30 ps rms. Two main t...

  6. 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.

  7. 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.

  8. Superior memory efficiency of quantum devices for the simulation of continuous-time stochastic processes

    Science.gov (United States)

    Elliott, Thomas J.; Gu, Mile

    2018-03-01

    Continuous-time stochastic processes pervade everyday experience, and the simulation of models of these processes is of great utility. Classical models of systems operating in continuous-time must typically track an unbounded amount of information about past behaviour, even for relatively simple models, enforcing limits on precision due to the finite memory of the machine. However, quantum machines can require less information about the past than even their optimal classical counterparts to simulate the future of discrete-time processes, and we demonstrate that this advantage extends to the continuous-time regime. Moreover, we show that this reduction in the memory requirement can be unboundedly large, allowing for arbitrary precision even with a finite quantum memory. We provide a systematic method for finding superior quantum constructions, and a protocol for analogue simulation of continuous-time renewal processes with a quantum machine.

  9. Perceived Interpersonal Discrimination and Older Women’s Mental Health: Accumulation Across Domains, Attributions, and Time

    Science.gov (United States)

    Bécares, Laia; Zhang, Nan

    2018-01-01

    Abstract Experiencing discrimination is associated with poor mental health, but how cumulative experiences of perceived interpersonal discrimination across attributes, domains, and time are associated with mental disorders is still unknown. Using data from the Study of Women’s Health Across the Nation (1996–2008), we applied latent class analysis and generalized linear models to estimate the association between cumulative exposure to perceived interpersonal discrimination and older women’s mental health. We found 4 classes of perceived interpersonal discrimination, ranging from cumulative exposure to discrimination over attributes, domains, and time to none or minimal reports of discrimination. Women who experienced cumulative perceived interpersonal discrimination over time and across attributes and domains had the highest risk of depression (Center for Epidemiologic Studies Depression Scale score ≥16) compared with women in all other classes. This was true for all women regardless of race/ethnicity, although the type and severity of perceived discrimination differed across racial/ethnic groups. Cumulative exposure to perceived interpersonal discrimination across attributes, domains, and time has an incremental negative long-term association with mental health. Studies that examine exposure to perceived discrimination due to a single attribute in 1 domain or at 1 point in time underestimate the magnitude and complexity of discrimination and its association with health. PMID:29036550

  10. Stress within a Restricted Time Window Selectively Affects the Persistence of Long-Term Memory

    Science.gov (United States)

    Fang, Qin; Chai, Ning; Zhao, Li-Yan; Xue, Yan-Xue; Luo, Yi-Xiao; Jian, Min; Han, Ying; Shi, Hai-Shui; Lu, Lin; Wu, Ping; Wang, Ji-Shi

    2013-01-01

    The effects of stress on emotional memory are distinct and depend on the stages of memory. Memory undergoes consolidation and reconsolidation after acquisition and retrieval, respectively. Stress facilitates the consolidation but disrupts the reconsolidation of emotional memory. Previous research on the effects of stress on memory have focused on long-term memory (LTM) formation (tested 24 h later), but the effects of stress on the persistence of LTM (tested at least 1 week later) are unclear. Recent findings indicated that the persistence of LTM requires late-phase protein synthesis in the dorsal hippocampus. The present study investigated the effect of stress (i.e., cold water stress) during the late phase after the acquisition and retrieval of contextual fear memory in rats. We found that stress and corticosterone administration during the late phase (12 h) after acquisition, referred to as late consolidation, selectively enhanced the persistence of LTM, whereas stress during the late phase (12 h) after retrieval, referred to as late reconsolidation, selectively disrupted the restabilized persistence of LTM. Moreover, the effects of stress on the persistence of LTM were blocked by the corticosterone synthesis inhibitor metyrapone, which was administered before stress, suggesting that the glucocorticoid system is involved in the effects of stress on the persistence of LTM. We conclude that stress within a restricted time window after acquisition or retrieval selectively affects the persistence of LTM and depends on the glucocorticoid system. PMID:23544051

  11. Public mental health: the time is ripe for translation of evidence into practice

    OpenAIRE

    Wahlbeck, Kristian

    2015-01-01

    Public mental health deals with mental health promotion, prevention of mental disorders and suicide, reducing mental health inequalities, and governance and organization of mental health service provision. The full impact of mental health is largely unrecognized within the public health sphere, despite the increasing burden of disease attributable to mental and behavioral disorders. Modern public mental health policies aim at improving psychosocial health by addressing determinants of mental ...

  12. 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

  13. Quality of Life Outcomes in Community-based Mental Health Consumers: Comparisons with Population Norms and Changes over Time.

    Science.gov (United States)

    Happell, Brenda; Stanton, Robert; Hodgetts, Danya; Scott, David

    2016-01-01

    Quality of life is shown to be lower in people diagnosed with mental illness in comparison to the general population. The aim of this study is to examine the Quality of life in a subset of people accessing mental health services in a regional Queensland Centre. Thirty-seven people accessing mental health services completed the SF36 Health Survey on three occasions. Differences and relationships between Physical Composite Scores and Mental Composite Scores, comparisons with Australian population norms, and temporal change in Quality of Life were examined. Physical Composite Scores were significantly different to, but significantly correlated with, Mental Composite Scores on each occasion. Physical Composite Scores and Mental Composite Scores were significantly different to population norms, and did not vary significantly across time. The poor Quality of life of people with mental illness remains a significant challenge for the mental health workforce.

  14. 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...

  15. 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...

  16. Mental workload and cognitive task automaticity: an evaluation of subjective and time estimation metrics.

    Science.gov (United States)

    Liu, Y; Wickens, C D

    1994-11-01

    The evaluation of mental workload is becoming increasingly important in system design and analysis. The present study examined the structure and assessment of mental workload in performing decision and monitoring tasks by focusing on two mental workload measurements: subjective assessment and time estimation. The task required the assignment of a series of incoming customers to the shortest of three parallel service lines displayed on a computer monitor. The subject was either in charge of the customer assignment (manual mode) or was monitoring an automated system performing the same task (automatic mode). In both cases, the subjects were required to detect the non-optimal assignments that they or the computer had made. Time pressure was manipulated by the experimenter to create fast and slow conditions. The results revealed a multi-dimensional structure of mental workload and a multi-step process of subjective workload assessment. The results also indicated that subjective workload was more influenced by the subject's participatory mode than by the factor of task speed. The time estimation intervals produced while performing the decision and monitoring tasks had significantly greater length and larger variability than those produced while either performing no other tasks or performing a well practised customer assignment task. This result seemed to indicate that time estimation was sensitive to the presence of perceptual/cognitive demands, but not to response related activities to which behavioural automaticity has developed.

  17. Time trends in mental health care utilization in a Dutch area, 1976-1990

    NARCIS (Netherlands)

    Oldehinkel, AJ

    This paper concerns time trends in mental health care utilization in a Dutch area from 1976 to 1990. In general, there was an increase in the use of psychiatric services during the study period, both in terms of the number of new patients (per 1000 population) and in terms of the amount of care

  18. Involuntary Mental Time Travel and Its Effect on Prospective Teachers' Situational Intrinsic Motivations

    Science.gov (United States)

    Eren, Altay

    2010-01-01

    Recent cognitive psychological research has argued that involuntary mental time travel is an important individual difference variable that has the potential to affect an individual's motivation. However, this issue has not been empirically investigated in educational settings such as teacher education. Therefore, this study aimed to explore the…

  19. Nonvolatile write-once-read-many-times memory device with functionalized-nanoshells/PEDOT:PSS nanocomposites

    International Nuclear Information System (INIS)

    Avila-Nino, J.A.; Segura-Cardenas, E.; Sustaita, A.O.; Cruz-Cruz, I.; Lopez-Sandoval, R.; Reyes-Reyes, M.

    2011-01-01

    We have investigated the memory effect of the nanocomposites of functionalized carbon nanoshells (f-CNSs) mixed with poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS) polymer. The f-CNSs were synthesized by the spray pyrolysis method and functionalized in situ with functional groups (OH, COOH, C-H, C-OH) with the aim of improving their compatibility in the aqueous dispersion of PEDOT:PSS. The current-voltage (I-V) sweep curves at room temperature for the Al/f-CNSs, for certain concentrations range, embedded in a PEDOT:PSS layer/Al devices showed electrical bistability for write-once-read-many-times (WORM) memory devices. The memory effect observed in the devices can be explained due to the existence of trapped charges in the f-CNSs/PEDOT:PSS layer. The carrier transport mechanisms for the memory devices is studied and discussed.

  20. Nonvolatile write-once-read-many-times memory device with functionalized-nanoshells/PEDOT:PSS nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Avila-Nino, J.A.; Segura-Cardenas, E. [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Alvaro Obregon 64 Zona Centro, 78000 SLP (Mexico); Sustaita, A.O. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216, San Luis Potosi (Mexico); Cruz-Cruz, I. [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Alvaro Obregon 64 Zona Centro, 78000 SLP (Mexico); Lopez-Sandoval, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216, San Luis Potosi (Mexico); Reyes-Reyes, M., E-mail: reyesm@iico.uaslp.mx [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Alvaro Obregon 64 Zona Centro, 78000 SLP (Mexico)

    2011-03-25

    We have investigated the memory effect of the nanocomposites of functionalized carbon nanoshells (f-CNSs) mixed with poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS) polymer. The f-CNSs were synthesized by the spray pyrolysis method and functionalized in situ with functional groups (OH, COOH, C-H, C-OH) with the aim of improving their compatibility in the aqueous dispersion of PEDOT:PSS. The current-voltage (I-V) sweep curves at room temperature for the Al/f-CNSs, for certain concentrations range, embedded in a PEDOT:PSS layer/Al devices showed electrical bistability for write-once-read-many-times (WORM) memory devices. The memory effect observed in the devices can be explained due to the existence of trapped charges in the f-CNSs/PEDOT:PSS layer. The carrier transport mechanisms for the memory devices is studied and discussed.

  1. Time of Day Influences Memory Formation and dCREB2 Proteins in Drosophila

    Directory of Open Access Journals (Sweden)

    Robin eFropf

    2014-03-01

    Full Text Available Many biological phenomena oscillate under the control of the circadian system, exhibiting peaks and troughs of activity across the day/night cycle. In most animal models, memory formation also exhibits this property, but the underlying neuronal and molecular mechanisms remain unclear. The dCREB2 transcription factor shows circadian regulated oscillations in its activity, and has been shown to be important for both circadian biology and memory formation. We show that the time-of-day (TOD of behavioral training affects Drosophila memory formation. dCREB2 exhibits complex changes in protein levels across the daytime and nighttime, and these changes in protein abundance are likely to contribute to oscillations in dCREB2 activity and TOD effects on memory formation.

  2. Memory controllers for mixed-time-criticality systems architectures, methodologies and trade-offs

    CERN Document Server

    Goossens, Sven; Akesson, Benny; Goossens, Kees

    2016-01-01

    This book discusses the design and performance analysis of SDRAM controllers that cater to both real-time and best-effort applications, i.e. mixed-time-criticality memory controllers. The authors describe the state of the art, and then focus on an architecture template for reconfigurable memory controllers that addresses effectively the quickly evolving set of SDRAM standards, in terms of worst-case timing and power analysis, as well as implementation. A prototype implementation of the controller in SystemC and synthesizable VHDL for an FPGA development board are used as a proof of concept of the architecture template.

  3. Parietal EEG alpha suppression time of memory retrieval reflects memory load while the alpha power of memory maintenance is a composite of the visual process according to simultaneous and successive Sternberg memory tasks.

    Science.gov (United States)

    Okuhata, Shiho; Kusanagi, Takuya; Kobayashi, Tetsuo

    2013-10-25

    The present study investigated EEG alpha activity during visual Sternberg memory tasks using two different stimulus presentation modes to elucidate how the presentation mode affected parietal alpha activity. EEGs were recorded from 10 healthy adults during the Sternberg tasks in which memory items were presented simultaneously and successively. EEG power and suppression time (ST) in the alpha band (8-13Hz) were computed for the memory maintenance and retrieval phases. The alpha activity differed according to the presentation mode during the maintenance phase but not during the retrieval phase. Results indicated that parietal alpha power recorded during the maintenance phase did not reflect the memory load alone. In contrast, ST during the retrieval phase increased with the memory load for both presentation modes, indicating a serial memory scanning process, regardless of the presentation mode. These results indicate that there was a dynamic transition in the memory process from the maintenance phase, which was sensitive to external factors, toward the retrieval phase, during which the process converged on the sequential scanning process, the Sternberg task essentially required. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. Time-based prospective memory in young children-Exploring executive functions as a developmental mechanism.

    Science.gov (United States)

    Kretschmer, Anett; Voigt, Babett; Friedrich, Sylva; Pfeiffer, Kathrin; Kliegel, Matthias

    2014-01-01

    The present study investigated time-based prospective memory (PM) during the transition from kindergarten/preschool to school age and applied mediation models to test the impact of executive functions (working memory, inhibitory control) and time monitoring on time-based PM development. Twenty-five preschool (age: M = 5.75, SD = 0.28) and 22 primary school children (age: M = 7.83, SD = 0.39) participated. To examine time-based PM, children had to play a computer-based driving game requiring them to drive a car on a road without hitting others cars (ongoing task) and to refill the car regularly according to a fuel gauge, which serves as clock equivalent (PM task). The level of gas that was still left in the fuel gauge was not displayed on the screen and children had to monitor it via a button press (time monitoring). Results revealed a developmental increase in time-based PM performance from preschool to school age. Applying the mediation models, only working memory was revealed to influence PM development. Neither inhibitory control alone nor the mediation paths leading from both executive functions to time monitoring could explain the link between age and time-based PM. Thus, results of the present study suggest that working memory may be one key cognitive process driving the developmental growth of time-based PM during the transition from preschool to school age.

  5. Is Insecurity Worse for Well-Being in Turbulent Times? Mental Health in Context

    Science.gov (United States)

    Lam, Jack; Fan, Wen; Moen, Phyllis

    2014-01-01

    Using General Social Survey data, we examine whether any association between job insecurity and well-being is contingent on economic climate (comparing those interviewed in turbulent 2010 vs. pre-recessionary 2006), as well as income and gender. We find respondents with higher levels of job insecurity in 2010 reported lower levels of happiness compared to those similarly insecure in 2006. The positive relationship between job insecurity and days of poor mental health becomes more pronounced for those in the 3rd quartile of personal income in 2010, suggesting middle-class vulnerability during the economic downturn. Men (but not women) with higher insecurity report more days of poor mental health in both 2006 and 2010. These findings reinforce a “cycles of control” theoretical approach, given the mental health-job insecurity relationship is heightened for workers in turbulent times. PMID:25436177

  6. Accessing Information in Working Memory: Can the Focus of Attention Grasp Two Elements at the Same Time?

    Science.gov (United States)

    Oberauer, Klaus; Bialkova, Svetlana

    2009-01-01

    Processing information in working memory requires selective access to a subset of working-memory contents by a focus of attention. Complex cognition often requires joint access to 2 items in working memory. How does the focus select 2 items? Two experiments with an arithmetic task and 1 with a spatial task investigate time demands for successive…

  7. The Role of Memory and Integration in Early Time Concepts.

    Science.gov (United States)

    Levin, Iris; And Others

    1984-01-01

    A total of 630 boys and girls from kindergarten to second grade were asked to compare durations that differ in beginning times with those that differ in ending times. Possible sources of children's failure to integrate beginning and end points when comparing durations were discussed. (Author/CI)

  8. Coherence time of over a second in a telecom-compatible quantum memory storage material

    Science.gov (United States)

    Rančić, Miloš; Hedges, Morgan P.; Ahlefeldt, Rose L.; Sellars, Matthew J.

    2018-01-01

    Quantum memories for light will be essential elements in future long-range quantum communication networks. These memories operate by reversibly mapping the quantum state of light onto the quantum transitions of a material system. For networks, the quantum coherence times of these transitions must be long compared to the network transmission times, approximately 100 ms for a global communication network. Due to a lack of a suitable storage material, a quantum memory that operates in the 1,550 nm optical fibre communication band with a storage time greater than 1 μs has not been demonstrated. Here we describe the spin dynamics of 167Er3+: Y2SiO5 in a high magnetic field and demonstrate that this material has the characteristics for a practical quantum memory in the 1,550 nm communication band. We observe a hyperfine coherence time of 1.3 s. We also demonstrate efficient spin pumping of the entire ensemble into a single hyperfine state, a requirement for broadband spin-wave storage. With an absorption of 70 dB cm-1 at 1,538 nm and Λ transitions enabling spin-wave storage, this material is the first candidate identified for an efficient, broadband quantum memory at telecommunication wavelengths.

  9. Cardiorespiratory dynamic response to mental stress: a multivariate time-frequency analysis.

    Science.gov (United States)

    Widjaja, Devy; Orini, Michele; Vlemincx, Elke; Van Huffel, Sabine

    2013-01-01

    Mental stress is a growing problem in our society. In order to deal with this, it is important to understand the underlying stress mechanisms. In this study, we aim to determine how the cardiorespiratory interactions are affected by mental arithmetic stress and attention. We conduct cross time-frequency (TF) analyses to assess the cardiorespiratory coupling. In addition, we introduce partial TF spectra to separate variations in the RR interval series that are linearly related to respiration from RR interval variations (RRV) that are not related to respiration. The performance of partial spectra is evaluated in two simulation studies. Time-varying parameters, such as instantaneous powers and frequencies, are derived from the computed spectra. Statistical analysis is carried out continuously in time to evaluate the dynamic response to mental stress and attention. The results show an increased heart and respiratory rate during stress and attention, compared to a resting condition. Also a fast reduction in vagal activity is noted. The partial TF analysis reveals a faster reduction of RRV power related to (3 s) than unrelated to (30 s) respiration, demonstrating that the autonomic response to mental stress is driven by mechanisms characterized by different temporal scales.

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

    Science.gov (United States)

    Busler, Jessica N.; Lazarte, Alejandro A.

    2017-01-01

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

  11. Time-place learning over a lifetime : Absence of memory loss in trained old mice

    NARCIS (Netherlands)

    Mulder, Cornelis K; Reckman, Gerlof A R; Gerkema, Menno P; van der Zee, Eddy A

    Time-place learning (TPL) offers the possibility to study the functional interaction between cognition and the circadian system with aging. With TPL, animals link biological significant events with the location and the time of day. This what-where-when type of memory provides animals with an

  12. Time-Place Learning over a Lifetime: Absence of Memory Loss in Trained Old Mice

    Science.gov (United States)

    Mulder, Cornelis K.; Reckman, Gerlof A. R.; Gerkema, Menno P.; Van der Zee, Eddy A.

    2015-01-01

    Time-place learning (TPL) offers the possibility to study the functional interaction between cognition and the circadian system with aging. With TPL, animals link biological significant events with the location and the time of day. This what-where-when type of memory provides animals with an experience-based daily schedule. Mice were tested for…

  13. 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.

  14. Effects of different timing of stress on corticosterone, BDNF and memory in male rats.

    Science.gov (United States)

    Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad Reza; Hosseini, Nasrin

    2015-02-01

    Learning and memory seem to be affected by chronic stress. Previous reports have considered chronic stress as a precipitating factor of different neuropsychological disorders, while others reported neurobiological adaptations following stress. The present study investigated the effects of chronic stress before, after, and during learning on the changes of learning and memory, on serum and hippocampal levels of corticosterone (CORT), brain-derived neurotrophic factor (BDNF) and body weight in rats. Male Wistar rats were randomly divided into four groups (n=10) including Control (Co), Stress-Learning-Rest (St-L-Re), Rest-Learning-Stress (Re-L-St), and Stress-Learning-Stress (St-L-St) groups. The chronic restraint stress was applied 6 h/day for 21 days. Moreover, the passive avoidance test was used to assess memory deficit, 1, 7, and 21 days after training. At the end of experiments, CORT and BDNF levels were measured. The findings did not support adaptation in chronic stress conditions. The acquisition time as well as the short and mid-term memories was significantly impaired in the St-L-Re group. Short, mid, and long-term memories were significantly impaired in the Re-L-St and St-L-St groups compared with the Co group, as a result of the enhancement of CORT and reduction of BDNF levels. In the St-L-St group, changes in memory functions were less pronounced than in the Re-L-St group. Also, body weight declined following the chronic stress, while recovery period enhanced the body weight gain in stressed rats. It can be concluded that a potential time-dependent involvement of stress and recovery period on the level of BDNF. Longer duration time of chronic stress might promote adaptive effects on memory and CORT level. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Time course of protein synthesis-dependent phase of olfactory memory in the cricket Gryllus bimaculatus.

    Science.gov (United States)

    Matsumoto, Yukihisa; Noji, Sumihare; Mizunami, Makoto

    2003-04-01

    The cricket Gryllus bimaculatus forms a stable olfactory memory that lasts for practically a lifetime. As a first step to elucidate the cellular mechanisms of olfactory learning and memory retention in crickets, we studied the dependency of memory retention on the de novo brain protein synthesis by injecting the protein synthesis inhibitor cycloheximide (CHX) into the head capsule. Injection of CHX inhibited (3)H-leucine incorporation into brain proteins by > 90% for 3 hr. Crickets were trained to associate peppermint odor with water (reward) and vanilla odor with saline solution (non-reward) and were injected with CHX before or at different times after training. Their odor preferences were tested at 2 hr, 1 day and 4 days after training. Memory retention at 2 hr after training was unaffected by CHX injection. However, the level of retention at 1 day and 4 days after training was lowered when CHX was injected 1 hour before training or at 1 hr or 6 hr after training. To study the time course of the development of CHX-sensitive memory phase, crickets that had been injected with CHX at 1 hr after training were tested at different times from 2 to 12 hr after training. The level of retention was unaffected up to 4 hr after training but significantly lowered at 5 hr after training, and the CHX-sensitive memory phase developed gradually during the next several hours. CHX dissociates two phases of olfactory memory in crickets: earlier protein synthesis-independent phase ( 5 hr) protein synthesis-dependent phase.

  16. Memory Efficient VLSI Implementation of Real-Time Motion Detection System Using FPGA Platform

    Directory of Open Access Journals (Sweden)

    Sanjay Singh

    2017-06-01

    Full Text Available Motion detection is the heart of a potentially complex automated video surveillance system, intended to be used as a standalone system. Therefore, in addition to being accurate and robust, a successful motion detection technique must also be economical in the use of computational resources on selected FPGA development platform. This is because many other complex algorithms of an automated video surveillance system also run on the same platform. Keeping this key requirement as main focus, a memory efficient VLSI architecture for real-time motion detection and its implementation on FPGA platform is presented in this paper. This is accomplished by proposing a new memory efficient motion detection scheme and designing its VLSI architecture. The complete real-time motion detection system using the proposed memory efficient architecture along with proper input/output interfaces is implemented on Xilinx ML510 (Virtex-5 FX130T FPGA development platform and is capable of operating at 154.55 MHz clock frequency. Memory requirement of the proposed architecture is reduced by 41% compared to the standard clustering based motion detection architecture. The new memory efficient system robustly and automatically detects motion in real-world scenarios (both for the static backgrounds and the pseudo-stationary backgrounds in real-time for standard PAL (720 × 576 size color video.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. Dynamics of continuous-time bidirectional associative memory neural networks with impulses and their discrete counterparts

    International Nuclear Information System (INIS)

    Huo Haifeng; Li Wantong

    2009-01-01

    This paper is concerned with the global stability characteristics of a system of equations modelling the dynamics of continuous-time bidirectional associative memory neural networks with impulses. Sufficient conditions which guarantee the existence of a unique equilibrium and its exponential stability of the networks are obtained. For the goal of computation, discrete-time analogues of the corresponding continuous-time bidirectional associative memory neural networks with impulses are also formulated and studied. Our results show that the above continuous-time and discrete-time systems with impulses preserve the dynamics of the networks without impulses when we make some modifications and impose some additional conditions on the systems, the convergence characteristics dynamics of the networks are preserved by both continuous-time and discrete-time systems with some restriction imposed on the impulse effect.

  3. Long-memory time series theory and methods

    CERN Document Server

    Palma, Wilfredo

    2007-01-01

    Wilfredo Palma, PhD, is Chairman and Professor of Statistics in the Department of Statistics at Pontificia Universidad Católica de Chile. Dr. Palma has published several refereed articles and has received over a dozen academic honors and awards. His research interests include time series analysis, prediction theory, state space systems, linear models, and econometrics.

  4. Neurocognitive Mechanisms of Prejudice Formation: The Role of Time-Dependent Memory Consolidation.

    Science.gov (United States)

    Enge, Luke R; Lupo, Amber K; Zárate, Michael A

    2015-07-01

    Prejudice is generally thought to derive from learned, emotion-laden experiences. The mechanisms underlying the formation of prejudice over time, however, remain unknown. In the present research, we proposed and tested hypotheses regarding prejudice formation derived from research on memory consolidation and social perception. We hypothesized that time-dependent memory consolidation would produce better implicit memory for negative out-group information and positive in-group information, compared with negative in-group information and positive out-group information. Fifty undergraduates learned positive and negative information about racial in-group (Latino) and out-group (African American) targets. Participants returned after both a short time delay (2-6 hr after the learning session) and a long time delay (48 hr after the learning session) to complete a lexical decision task. Results demonstrated that participants responded to information consistent with an in-group bias faster after a long time delay than after a short time delay. Our findings have important implications for the study of social perception and memory consolidation. © The Author(s) 2015.

  5. The effect of part-time sick leave for employees with mental disorders.

    Science.gov (United States)

    Høgelund, Jan; Holm, Anders; Eplov, Lene Falgaard

    2012-12-01

    Part-time sick leave (PTSL) allows employees on full-time sick leave (FTSL) to resume work at reduced hours. When the partly absent employee's health improves, working hours are increased until the employee is able to work regular hours. Studies have found that PTSL is an effective instrument for reducing sick leave durations for employees with musculoskeletal disorders and for employees on sick leave in general. This is the first published article to document how PTSL affects sick leave durations for employees with mental disorders. The aim is to estimate the effect of PTSL on the duration until returning to regular working hours for employees with mental disorders. We compare this effect to that of PTSL for employees with non-mental disorders ('other disorders'). We use combined survey and register data about 226 employees on long-term sick leave with mental disorders and 638 employees with other disorders. These data contain information about type of disorder, PTSL and FTSL (full-time sick leave) durations, and various background characteristics. We use a mixed proportional hazard regression model that allows us to control for unobserved differences between employees on PTSL and those on FTSL. Our analyses show that PTSL has no effect on the duration until returning to regular working hours for employees with mental disorders. Furthermore, looking at specific disorders such as depression and stress-related conditions, we find no significant effects of PTSL. In contrast, in line with previous research, we find that PTSL significantly reduces the duration until returning to regular working hours for employees with other disorders. The analyses also illustrate the importance of controlling for unobserved differences between employees on PTSL and those on FTSL. Without this control, PTSL significantly reduces the duration until returning to regular working hours. When we control for unobserved characteristics, this effect decreases, and for employees with mental

  6. 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,…

  7. An Incremental Time-delay Neural Network for Dynamical Recurrent Associative Memory

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An incremental time-delay neural network based on synapse growth, which is suitable for dynamic control and learning of autonomous robots, is proposed to improve the learning and retrieving performance of dynamical recurrent associative memory architecture. The model allows steady and continuous establishment of associative memory for spatio-temporal regularities and time series in discrete sequence of inputs. The inserted hidden units can be taken as the long-term memories that expand the capacity of network and sometimes may fade away under certain condition. Preliminary experiment has shown that this incremental network may be a promising approach to endow autonomous robots with the ability of adapting to new data without destroying the learned patterns. The system also benefits from its potential chaos character for emergence.

  8. Memory Efficient Hard Real-Time Garbage Collection

    OpenAIRE

    Ritzau, Tobias

    2003-01-01

    As the development of hardware progresses, computers are expected to solve increasingly complex problems. However, solving more complex problems requires more complex software. To be able to develop these software systems, new programming languages with new features and higher abstraction levels are introduced. These features are designed to ease development, but sometimes they also make the runtime behavior unpredictable. Such features can not be used in real-time systems. A feature that tra...

  9. 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.

  10. Reaction Times to Consecutive Automation Failures: A Function of Working Memory and Sustained Attention.

    Science.gov (United States)

    Jipp, Meike

    2016-12-01

    This study explored whether working memory and sustained attention influence cognitive lock-up, which is a delay in the response to consecutive automation failures. Previous research has demonstrated that the information that automation provides about failures and the time pressure that is associated with a task influence cognitive lock-up. Previous research has also demonstrated considerable variability in cognitive lock-up between participants. This is why individual differences might influence cognitive lock-up. The present study tested whether working memory-including flexibility in executive functioning-and sustained attention might be crucial in this regard. Eighty-five participants were asked to monitor automated aircraft functions. The experimental manipulation consisted of whether or not an initial automation failure was followed by a consecutive failure. Reaction times to the failures were recorded. Participants' working-memory and sustained-attention abilities were assessed with standardized tests. As expected, participants' reactions to consecutive failures were slower than their reactions to initial failures. In addition, working-memory and sustained-attention abilities enhanced the speed with which participants reacted to failures, more so with regard to consecutive than to initial failures. The findings highlight that operators with better working memory and sustained attention have small advantages when initial failures occur, but their advantages increase across consecutive failures. The results stress the need to consider personnel selection strategies to mitigate cognitive lock-up in general and training procedures to enhance the performance of low ability operators. © 2016, Human Factors and Ergonomics Society.

  11. Sensory-specific clock components and memory mechanisms: investigation with parallel timing.

    Science.gov (United States)

    Gamache, Pierre-Luc; Grondin, Simon

    2010-05-01

    A challenge for researchers in the time-perception field is to determine whether temporal processing is governed by a central mechanism or by multiple mechanisms working in concert. Behavioral studies of parallel timing offer interesting insights into the question, although the conclusions fail to converge. Most of these studies focus on the number-of-clocks issue, but the commonality of memory mechanisms involved in time processing is often neglected. The present experiment aims to address a straightforward question: do signals from different modalities marking time intervals share the same clock and/or the same memory resources? To this end, an interval reproduction task involving the parallel timing of two sensory signals presented either in the same modality or in different modalities was conducted. The memory component was tested by manipulating the delay separating the presentation of the target intervals and the moment when the reproduction of one of these began. Results show that there is more variance when only visually marked intervals are presented, and this effect is exacerbated with longer retention delays. Finally, when there is only one interval to process, encoding the interval with signals delivered from two modalities helps to reduce variance. Taken together, these results suggest that the hypothesis stating that there are sensory-specific clock components and memory mechanisms is viable.

  12. Working Memory and Auditory Imagery Predict Sensorimotor Synchronization with Expressively Timed Music.

    Science.gov (United States)

    Colley, Ian D; Keller, Peter E; Halpern, Andrea R

    2017-08-11

    Sensorimotor synchronization (SMS) is prevalent and readily studied in musical settings, as most people are able to perceive and synchronize with a beat (e.g. by finger tapping). We took an individual differences approach to understanding SMS to real music characterized by expressive timing (i.e. fluctuating beat regularity). Given the dynamic nature of SMS, we hypothesized that individual differences in working memory and auditory imagery-both fluid cognitive processes-would predict SMS at two levels: 1) mean absolute asynchrony (a measure of synchronization error), and 2) anticipatory timing (i.e. predicting, rather than reacting to beat intervals). In Experiment 1, participants completed two working memory tasks, four auditory imagery tasks, and an SMS-tapping task. Hierarchical regression models were used to predict SMS performance, with results showing dissociations among imagery types in relation to mean absolute asynchrony, and evidence of a role for working memory in anticipatory timing. In Experiment 2, a new sample of participants completed an expressive timing perception task to examine the role of imagery in perception without action. Results suggest that imagery vividness is important for perceiving and control is important for synchronizing with, irregular but ecologically valid musical time series. Working memory is implicated in synchronizing by anticipating events in the series.

  13. Borges' ‘late style’: literature, memory and time

    Directory of Open Access Journals (Sweden)

    Adriana Mancini

    2017-12-01

    Full Text Available Using the concept of ‘late style’ established by Adorno (1993 in his analysis of the last quartets of Beethoven and adopted up by Said (2006, we consider the mature Borges’s essays on time and immortality and his exploration of the themes of The Double and insomnia in his fictional works Stories of the Book of Sand and poem The Cipher. We analyse some key characteristics of Borges’s style – coincidences and dissidences – and compare them to those proposed by Adorno for artistic production in later years.

  14. Emotional distress and positive and negative memories from military deployment: The influence of PTSD symptoms and time

    DEFF Research Database (Denmark)

    Niziurski, Julie Ann; Johannessen, Kim Berg; Berntsen, Dorthe

    2017-01-01

    positive deployment memories from a company of 337 soldiers who were deployed together to Afghanistan. We examined how the level of emotional distress of the soldiers and the valence of the memory were related to the emotional intensity, experience of reliving, rehearsal and coherence of the memories......, and how the perceived impact of these memories changed over time. We found that soldiers with higher levels of post-traumatic stress disorder (PTSD) symptoms were more affected by both their negative and positive memories, compared with soldiers with lower levels of PTSD symptoms. Emotional intensity...... of the most negative memory increased over time in the group with highest levels of PTSD symptoms, but dropped in the other groups. The present study adds to the literature on emotion and autobiographical memory and how this relationship interacts with an individual’s present level of emotional distress...

  15. Mapping working memory retrieval in space and in time : A combined electroencephalography and electrocorticography approach

    NARCIS (Netherlands)

    Zhang, Qiong; van Vugt, Marieke; Borst, Jelmer P; Anderson, John R

    2018-01-01

    In this study, we investigated the time course and neural correlates of the retrieval process underlying visual working memory. We made use of a rare dataset in which the same task was recorded using both scalp electroencephalography (EEG) and Electrocorticography (ECoG), respectively. This allowed

  16. Shared random access memory resource for multiprocessor real-time systems

    International Nuclear Information System (INIS)

    Dimmler, D.G.; Hardy, W.H. II

    1977-01-01

    A shared random-access memory resource is described which is used within real-time data acquisition and control systems with multiprocessor and multibus organizations. Hardware and software aspects are discussed in a specific example where interconnections are done via a UNIBUS. The general applicability of the approach is also discussed

  17. Robust stability of bidirectional associative memory neural networks with time delays

    Science.gov (United States)

    Park, Ju H.

    2006-01-01

    Based on the Lyapunov Krasovskii functionals combined with linear matrix inequality approach, a novel stability criterion is proposed for asymptotic stability of bidirectional associative memory neural networks with time delays. A novel delay-dependent stability criterion is given in terms of linear matrix inequalities, which can be solved easily by various optimization algorithms.

  18. Robust stability of bidirectional associative memory neural networks with time delays

    International Nuclear Information System (INIS)

    Park, Ju H.

    2006-01-01

    Based on the Lyapunov-Krasovskii functionals combined with linear matrix inequality approach, a novel stability criterion is proposed for asymptotic stability of bidirectional associative memory neural networks with time delays. A novel delay-dependent stability criterion is given in terms of linear matrix inequalities, which can be solved easily by various optimization algorithms

  19. The roles of chronological age and time perspective in memory positivity.

    Science.gov (United States)

    Kan, Irene P; Garrison, Shaina L; Drummey, Anna B; Emmert, Brian E; Rogers, Leeland L

    2018-07-01

    The observation that older adults show enhanced cognition for emotionally positive information has been labeled the positivity effect (Reed, Chan, & Mikels, 2014). According to the Socioemotional Selectivity Theory (SST, Carstensen, 1991), a prominent lifespan development theory, cognition is strongly influenced by motivational goals, and these goals are impacted by subjective time perspective. Although the positivity effect is most commonly observed in older adults, as age usually co-varies with time perspective, the SST posits that time perspective, not age, is the key explanatory factor of positivity. We examined the effects of these predictors on positivity in an episodic memory task in younger and older adults and found that age, not time perspective, was a key predictor of memory positivity. Our results add to the growing literature that challenge the notion that time perspective is the driving force behind age-related differences in emotional processing and functioning.

  20. Time of day affects implicit memory for unattended stimuli.

    Science.gov (United States)

    Rothen, Nicolas; Meier, Beat

    2016-11-01

    We investigated whether circadian arousal affects perceptual priming as a function of whether stimuli were attended or ignored during learning. We tested 160 participants on- and off-peak with regards to their circadian arousal. In the study phase, they were presented with two superimposed pictures in different colours. They had to name the pictures of one colour while ignoring the others. In the test phase, they were presented with the same and randomly intermixed new pictures. Each picture was presented in black colour in a fragment completion task. Priming was measured as the difference in fragmentation level at which the pictures from the study phase were named compared to the new pictures. Priming was stronger for attended than ignored pictures. Time of day affected priming only for ignored pictures, with stronger priming effects off-peak than on-peak. Thus, circadian arousal seems to favour the encoding of unattended materials specifically at off-peak. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. 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

  2. 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

  3. Chinese and Australians showed difference in mental time travel in emotion and content but not specificity

    Directory of Open Access Journals (Sweden)

    Xing-jie eChen

    2015-06-01

    Full Text Available Mental time travel refers to the ability to recall episodic past and imagine future events. The present study aimed to investigate cultural differences in mental time travel between Chinese and Australian university students. A total of 231 students (108 Chinese & 123 Australians participated in the study. Their mental time travel abilities were measured by the Sentence Completion for Events from the Past Test (SCEPT and the Sentence Completion for Events in the Future Test (SCEFT. Results showed that there were no cultural differences in the number of specific events generated for the past or future. Significant differences between the Chinese and Australian participants were found mainly in the emotional valence and content of the events generated. Both Chinese and Australian participants generated more specific positive events compared to negative events when thinking about the future and Chinese participants were more positive about their past than Australian participants when recalled specific events. For content, Chinese participants recalled more events about their interpersonal relationships, while Australian participants imagined more about personal future achievements. These findings shed some lights on cultural differences in episodic past and future thinking.

  4. Short-term visual memory for location in depth: A U-shaped function of time.

    Science.gov (United States)

    Reeves, Adam; Lei, Quan

    2017-10-01

    Short-term visual memory was studied by displaying arrays of four or five numerals, each numeral in its own depth plane, followed after various delays by an arrow cue shown in one of the depth planes. Subjects reported the numeral at the depth cued by the arrow. Accuracy fell with increasing cue delay for the first 500 ms or so, and then recovered almost fully. This dipping pattern contrasts with the usual iconic decay observed for memory traces. The dip occurred with or without a verbal or color-shape retention load on working memory. In contrast, accuracy did not change with delay when a tonal cue replaced the arrow cue. We hypothesized that information concerning the depths of the numerals decays over time in sensory memory, but that cued recall is aided later on by transfer to a visual memory specialized for depth. This transfer is sufficiently rapid with a tonal cue to compensate for the sensory decay, but it is slowed by the need to tag the arrow cue's depth relative to the depths of the numerals, exposing a dip when sensation has decayed and transfer is not yet complete. A model with a fixed rate of sensory decay and varied transfer rates across individuals captures the dip as well as the cue modality effect.

  5. Working Memory Load Affects Processing Time in Spoken Word Recognition: Evidence from Eye-Movements

    Science.gov (United States)

    Hadar, Britt; Skrzypek, Joshua E.; Wingfield, Arthur; Ben-David, Boaz M.

    2016-01-01

    In daily life, speech perception is usually accompanied by other tasks that tap into working memory capacity. However, the role of working memory on speech processing is not clear. The goal of this study was to examine how working memory load affects the timeline for spoken word recognition in ideal listening conditions. We used the “visual world” eye-tracking paradigm. The task consisted of spoken instructions referring to one of four objects depicted on a computer monitor (e.g., “point at the candle”). Half of the trials presented a phonological competitor to the target word that either overlapped in the initial syllable (onset) or at the last syllable (offset). Eye movements captured listeners' ability to differentiate the target noun from its depicted phonological competitor (e.g., candy or sandal). We manipulated working memory load by using a digit pre-load task, where participants had to retain either one (low-load) or four (high-load) spoken digits for the duration of a spoken word recognition trial. The data show that the high-load condition delayed real-time target discrimination. Specifically, a four-digit load was sufficient to delay the point of discrimination between the spoken target word and its phonological competitor. Our results emphasize the important role working memory plays in speech perception, even when performed by young adults in ideal listening conditions. PMID:27242424

  6. Fast Mapping Across Time: Memory Processes Support Children's Retention of Learned Words.

    Science.gov (United States)

    Vlach, Haley A; Sandhofer, Catherine M

    2012-01-01

    Children's remarkable ability to map linguistic labels to referents in the world is commonly called fast mapping. The current study examined children's (N = 216) and adults' (N = 54) retention of fast-mapped words over time (immediately, after a 1-week delay, and after a 1-month delay). The fast mapping literature often characterizes children's retention of words as consistently high across timescales. However, the current study demonstrates that learners forget word mappings at a rapid rate. Moreover, these patterns of forgetting parallel forgetting functions of domain-general memory processes. Memory processes are critical to children's word learning and the role of one such process, forgetting, is discussed in detail - forgetting supports extended mapping by promoting the memory and generalization of words and categories.

  7. 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.

  8. Changes in recognition memory over time: an ERP investigation into vocabulary learning.

    Directory of Open Access Journals (Sweden)

    Shekeila D Palmer

    Full Text Available Although it seems intuitive to assume that recognition memory fades over time when information is not reinforced, some aspects of word learning may benefit from a period of consolidation. In the present study, event-related potentials (ERP were used to examine changes in recognition memory responses to familiar and newly learned (novel words over time. Native English speakers were taught novel words associated with English translations, and subsequently performed a Recognition Memory task in which they made old/new decisions in response to both words (trained word vs. untrained word, and novel words (trained novel word vs. untrained novel word. The Recognition task was performed 45 minutes after training (Day 1 and then repeated the following day (Day 2 with no additional training session in between. For familiar words, the late parietal old/new effect distinguished old from new items on both Day 1 and Day 2, although response to trained items was significantly weaker on Day 2. For novel words, the LPC again distinguished old from new items on both days, but the effect became significantly larger on Day 2. These data suggest that while recognition memory for familiar items may fade over time, recognition of novel items, conscious recollection in particular may benefit from a period of consolidation.

  9. Continuous-Time Random Walk with multi-step memory: an application to market dynamics

    Science.gov (United States)

    Gubiec, Tomasz; Kutner, Ryszard

    2017-11-01

    An extended version of the Continuous-Time Random Walk (CTRW) model with memory is herein developed. This memory involves the dependence between arbitrary number of successive jumps of the process while waiting times between jumps are considered as i.i.d. random variables. This dependence was established analyzing empirical histograms for the stochastic process of a single share price on a market within the high frequency time scale. Then, it was justified theoretically by considering bid-ask bounce mechanism containing some delay characteristic for any double-auction market. Our model appeared exactly analytically solvable. Therefore, it enables a direct comparison of its predictions with their empirical counterparts, for instance, with empirical velocity autocorrelation function. Thus, the present research significantly extends capabilities of the CTRW formalism. Contribution to the Topical Issue "Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

  10. A generalized voter model with time-decaying memory on a multilayer network

    Science.gov (United States)

    Zhong, Li-Xin; Xu, Wen-Juan; Chen, Rong-Da; Zhong, Chen-Yang; Qiu, Tian; Shi, Yong-Dong; Wang, Li-Liang

    2016-09-01

    By incorporating a multilayer network and time-decaying memory into the original voter model, we investigate the coupled effects of spatial and temporal accumulation of peer pressure on the consensus. Heterogeneity in peer pressure and the time-decaying mechanism are both shown to be detrimental to the consensus. We find the transition points below which a consensus can always be reached and above which two opposed opinions are more likely to coexist. Our mean-field analysis indicates that the phase transitions in the present model are governed by the cumulative influence of peer pressure and the updating threshold. We find a functional relation between the consensus threshold and the decay rate of the influence of peer is found. As to the pressure. The time required to reach a consensus is governed by the coupling of the memory length and the decay rate. An intermediate decay rate may greatly reduce the time required to reach a consensus.

  11. Duration and numerical estimation in right brain-damaged patients with and without neglect: Lack of support for a mental time line.

    Science.gov (United States)

    Masson, Nicolas; Pesenti, Mauro; Dormal, Valérie

    2016-08-01

    Previous studies have shown that left neglect patients are impaired when they have to orient their attention leftward relative to a standard in numerical comparison tasks. This finding has been accounted for by the idea that numerical magnitudes are represented along a spatial continuum oriented from left to right with small magnitudes on the left and large magnitudes on the right. Similarly, it has been proposed that duration could be represented along a mental time line that shares the properties of the number continuum. By comparing directly duration and numerosity processing, this study investigates whether or not the performance of neglect patients supports the hypothesis of a mental time line. Twenty-two right brain-damaged patients (11 with and 11 without left neglect), as well as 11 age-matched healthy controls, had to judge whether a single dot presented visually lasted shorter or longer than 500 ms and whether a sequence of flashed dots was smaller or larger than 5. Digit spans were also assessed to measure verbal working memory capacities. In duration comparison, no spatial-duration bias was found in neglect patients. Moreover, a significant correlation between verbal working memory and duration performance was observed in right brain-damaged patients, irrespective of the presence or absence of neglect. In numerical comparison, only neglect patients showed an enhanced distance effect for numerical magnitude smaller than the standard. These results do not support the hypothesis of the existence of a mental continuum oriented from left to right for duration. We discuss an alternative account to explain the duration impairment observed in right brain-damaged patients. © 2015 The British Psychological Society.

  12. 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.

  13. An optimal multi-channel memory controller for real-time systems

    NARCIS (Netherlands)

    Gomony, M.D.; Akesson, K.B.; Goossens, K.G.W.

    2013-01-01

    Optimal utilization of a multi-channel memory, such as Wide IO DRAM, as shared memory in multi-processor platforms depends on the mapping of memory clients to the memory channels, the granularity at which the memory requests are interleaved in each channel, and the bandwidth and memory capacity

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Public mental health: the time is ripe for translation of evidence into practice.

    Science.gov (United States)

    Wahlbeck, Kristian

    2015-02-01

    Public mental health deals with mental health promotion, prevention of mental disorders and suicide, reducing mental health inequalities, and governance and organization of mental health service provision. The full impact of mental health is largely unrecognized within the public health sphere, despite the increasing burden of disease attributable to mental and behavioral disorders. Modern public mental health policies aim at improving psychosocial health by addressing determinants of mental health in all public policy areas. Stigmatization of mental disorders is a widespread phenomenon that constitutes a barrier for help-seeking and for the development of health care services, and is thus a core issue in public mental health actions. Lately, there has been heightened interest in the promotion of positive mental health and wellbeing. Effective programmes have been developed for promoting mental health in everyday settings such as families, schools and workplaces. New evidence indicates that many mental disorders and suicides are preventable by public mental health interventions. Available evidence favours the population approach over high-risk approaches. Public mental health emphasizes the role of primary care in the provision of mental health services to the population. The convincing evidence base for population-based mental health interventions asks for actions for putting evidence into practice. © 2015 World Psychiatric Association.

  19. Time and Memory Efficient Online Piecewise Linear Approximation of Sensor Signals.

    Science.gov (United States)

    Grützmacher, Florian; Beichler, Benjamin; Hein, Albert; Kirste, Thomas; Haubelt, Christian

    2018-05-23

    Piecewise linear approximation of sensor signals is a well-known technique in the fields of Data Mining and Activity Recognition. In this context, several algorithms have been developed, some of them with the purpose to be performed on resource constrained microcontroller architectures of wireless sensor nodes. While microcontrollers are usually constrained in computational power and memory resources, all state-of-the-art piecewise linear approximation techniques either need to buffer sensor data or have an execution time depending on the segment’s length. In the paper at hand, we propose a novel piecewise linear approximation algorithm, with a constant computational complexity as well as a constant memory complexity. Our proposed algorithm’s worst-case execution time is one to three orders of magnitude smaller and its average execution time is three to seventy times smaller compared to the state-of-the-art Piecewise Linear Approximation (PLA) algorithms in our experiments. In our evaluations, we show that our algorithm is time and memory efficient without sacrificing the approximation quality compared to other state-of-the-art piecewise linear approximation techniques, while providing a maximum error guarantee per segment, a small parameter space of only one parameter, and a maximum latency of one sample period plus its worst-case execution time.

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

    Science.gov (United States)

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

    2016-09-15

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

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

    OpenAIRE

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

    2014-01-01

    Humans are able to transcend the present and mentally travel to another time, place, or perspective. Mentally projecting ourselves backwards (i.e., episodic memory) or forwards (i.e., episodic foresight) in time are crucial characteristics of the human memory system. Indeed, over the past few years, episodic memory has been argued to be involved both in our capacity to retrieve our personal past experiences and in our ability to imagine and foresee future scenarios. However, recent theory and...

  2. [The Role of Brodmann Area 12: Taste, Social Cognition, and Mental Time].

    Science.gov (United States)

    Kawamura, Mitsuru

    2017-04-01

    Broadman area 12, together with area 11, is located in the orbitofrontal area. A voxel-based morphometric (VBM) study revealed the association between bilateral brodmann areas 12/47 and taste disturbance in individuals with frontotemporal lobar degeneration (FTLD). In our VBM study in patients with Parkinson's disease, decision-making impairments were associated with atrophy of the bilateral Brodmann area 12, indicating that this area may play an important role in social cognitive function. Our recent study also demonstrated that this area may serve as time order judgement or mental time travel.

  3. Effects of spatial attention on mental time travel in patients with neglect.

    Science.gov (United States)

    Anelli, Filomena; Avanzi, Stefano; Arzy, Shahar; Mancuso, Mauro; Frassinetti, Francesca

    2018-04-01

    Numerous studies agree that time is represented in spatial terms in the brain. Here we investigate how a deficit in orienting attention in space influences the ability to mentally travel in time, that is to recall the past and anticipate the future. Right brain-damaged patients, with (RBD-N+) and without neglect (RBD-N-), and healthy controls (HC) were subjected to a Mental Time Travel (MTT) task. Participants were asked to project themselves in time to past, present or future (i.e., self-projection) and, for each self-projection, to judge whether events were located relatively in the past or the future (i.e., self-reference). The MTT-task was performed before and after a manipulation, through prismatic adaptation (PA), inducing a leftward shift of spatial attention. Before PA, RBD-N+ were slower for future than for past events, whereas RBD-N- and HC responded similarly to past and future events. A leftward shift of spatial attention by PA reduced the difference in past/future processing in RBD-N+ and fastened RBD-N- and HC's response to past events. Assuming that time concepts, such as past/future, are coded with a left-to-right order on a mental time line (MTL), a recursive search of future-events can explain neglect patients' performance. Improvement of the spatial deficit following PA reduces the recursive search of future events on the rightmost part of the MTL, facilitating exploration of past events on the leftmost part of the MTL, finally favoring the correct location of past and future events. In addition, the study of the anatomical correlates of the temporal deficit in mental time travel through voxel-based lesion-symptom mapping showed a correlation with a lesion located in the insula and in the thalamus. These findings provide new insights about the inter-relations of space and time, and can pave the way to a procedure to rehabilitate a deficit in these cognitive domains. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. The influence of time on task on mind wandering and visual working memory.

    Science.gov (United States)

    Krimsky, Marissa; Forster, Daniel E; Llabre, Maria M; Jha, Amishi P

    2017-12-01

    Working memory relies on executive resources for successful task performance, with higher demands necessitating greater resource engagement. In addition to mnemonic demands, prior studies suggest that internal sources of distraction, such as mind wandering (i.e., having off-task thoughts) and greater time on task, may tax executive resources. Herein, the consequences of mnemonic demand, mind wandering, and time on task were investigated during a visual working memory task. Participants (N=143) completed a delayed-recognition visual working memory task, with mnemonic load for visual objects manipulated across trials (1 item=low load; 2 items=high load) and subjective mind wandering assessed intermittently throughout the experiment using a self-report Likert-type scale (1=on-task, 6=off-task). Task performance (correct/incorrect response) and self-reported mind wandering data were evaluated by hierarchical linear modeling to track trial-by-trial fluctuations. Performance declined with greater time on task, and the rate of decline was steeper for high vs low load trials. Self-reported mind wandering increased over time, and significantly varied asa function of both load and time on task. Participants reported greater mind wandering at the beginning of the experiment for low vs. high load trials; however, with greater time on task, more mind wandering was reported during high vs. low load trials. These results suggest that the availability of executive resources in support of working memory maintenance processes fluctuates in a demand-sensitive manner with time on task, and may be commandeered by mind wandering. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Neurogenomic signatures of spatiotemporal memories in time-trained forager honey bees

    Science.gov (United States)

    Naeger, Nicholas L.; Van Nest, Byron N.; Johnson, Jennifer N.; Boyd, Sam D.; Southey, Bruce R.; Rodriguez-Zas, Sandra L.; Moore, Darrell; Robinson, Gene E.

    2011-01-01

    Honey bees can form distinct spatiotemporal memories that allow them to return repeatedly to different food sources at different times of day. Although it is becoming increasingly clear that different behavioral states are associated with different profiles of brain gene expression, it is not known whether this relationship extends to states that are as dynamic and specific as those associated with foraging-related spatiotemporal memories. We tested this hypothesis by training different groups of foragers from the same colony to collect sucrose solution from one of two artificial feeders; each feeder was in a different location and had sucrose available at a different time, either in the morning or afternoon. Bees from both training groups were collected at both the morning and afternoon training times to result in one set of bees that was undergoing stereotypical food anticipatory behavior and another that was inactive for each time of day. Between the two groups with the different spatiotemporal memories, microarray analysis revealed that 1329 genes were differentially expressed in the brains of honey bees. Many of these genes also varied with time of day, time of training or state of food anticipation. Some of these genes are known to be involved in a variety of biological processes, including metabolism and behavior. These results indicate that distinct spatiotemporal foraging memories in honey bees are associated with distinct neurogenomic signatures, and the decomposition of these signatures into sets of genes that are also influenced by time or activity state hints at the modular composition of this complex neurogenomic phenotype. PMID:21346126

  6. 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.

  7. Digging up the Past: Space, Time, and Memory in Josef Haslinger’s "Fiona und Ferdinand"

    Directory of Open Access Journals (Sweden)

    Anna Souchuk

    2015-08-01

    Full Text Available Josef Haslinger’s story "Fiona und Ferdinand" (2006 revolves around a disclosed secret in its narrator’s childhood hometown, which implicates two (deceased village elders in a decades-old rape and murder mystery long blamed on two anonymous “Russian soldiers.” The discovery of two partial skeletons locked in a bedroom trunk awakens the narrator’s memory: years before as a child, he unearthed the same skeletons after first spying a finger bone buried in a stream. The identification of the bones is central in determining the perpetrators of the rape/murder, but no one -- and in particular the narrator’s mother -- seems interested in hearing the testimony of the crime’s lone eyewitness, now an aged woman. Instead, the revelation evokes a collective effort to willfully impede any investigation into the truth, presumably as a means to maintain the town’s dual pretenses of order and respectability. "Fiona und Ferdinand" emphasizes Haslinger’s preoccupation with the Austrian failure to confront its own past, specifically via families as fundamental units of transmission and memory. In this analysis of the text, I explore Haslinger’s treatment of space, time, and memory in several ways. First, I examine how his notion of “officially sanctioned memory” intersects with a landscape that contains past and present alike. Second, I discuss how bodies, either the violated female body or the rotted skeletons Fiona and Ferdinand, are emblems that raise discussions of space, gender, and memory. Last, I consider collective memory and how it enables processes of forgetting. The reluctance to “dig up the past” is thematized in "Fiona und Ferdinand" using devices common throughout Haslinger’s oeuvre, and this paper will analyze the story through the lens of Haslinger-as-archaeologist, exploring how families, and the memories they possess, are both the key to truth and the foil to its revelation. 

  8. Acute Exercise and Motor Memory Consolidation: The Role of Exercise Timing

    Directory of Open Access Journals (Sweden)

    Richard Thomas

    2016-01-01

    Full Text Available High intensity aerobic exercise amplifies offline gains in procedural memory acquired during motor practice. This effect seems to be evident when exercise is placed immediately after acquisition, during the first stages of memory consolidation, but the importance of temporal proximity of the exercise bout used to stimulate improvements in procedural memory is unknown. The effects of three different temporal placements of high intensity exercise were investigated following visuomotor skill acquisition on the retention of motor memory in 48 young (24.0 ± 2.5 yrs, healthy male subjects randomly assigned to one of four groups either performing a high intensity (90% Maximal Power Output exercise bout at 20 min (EX90, 1 h (EX90+1, 2 h (EX90+2 after acquisition or rested (CON. Retention tests were performed at 1 d (R1 and 7 d (R7. At R1 changes in performance scores after acquisition were greater for EX90 than CON (p<0.001 and EX90+2 (p=0.001. At R7 changes in performance scores for EX90, EX90+1, and EX90+2 were higher than CON (p<0.001, p=0.008, and p=0.008, resp.. Changes for EX90 at R7 were greater than EX90+2 (p=0.049. Exercise-induced improvements in procedural memory diminish as the temporal proximity of exercise from acquisition is increased. Timing of exercise following motor practice is important for motor memory consolidation.

  9. Timing of Environmental Enrichment Affects Memory in the House Cricket, Acheta domesticus.

    Directory of Open Access Journals (Sweden)

    Heather S Mallory

    Full Text Available Learning appears to be ubiquitous among animals, as it plays a key role in many behaviors including foraging and reproduction. Although there is some genetic basis for differences in learning ability and memory retention, environment also plays an important role, as it does for any other trait. For example, adult animals maintained in enriched housing conditions learn faster and remember tasks for longer than animals maintained in impoverished conditions. Such plasticity in adult learning ability has often been linked to plasticity in the brain, and studies aimed at understanding the mechanisms, stimuli, and consequences of adult behavioral and brain plasticity are numerous. However, the role of experiences during post-embryonic development in shaping plasticity in adult learning ability and memory retention remain relatively unexplored. Using the house cricket (Acheta domesticus as a model organism, we developed a protocol to allow the odor preference of a large number of crickets to be tested in a short period of time. We then used this new protocol to examine how enrichment or impoverishment at two developmental stages (either the last nymphal instar or young adult affected adult memory. Our results show that regardless of nymphal rearing conditions, crickets that experienced an enriched rearing condition as young adults performed better on a memory task than individuals that experienced an impoverished condition. Older adult crickets (more than 1 week post adult molt did not demonstrate differences in memory of the odor task, regardless of rearing condition as a young adult. Our results suggest that environmentally-induced plasticity in memory may be restricted to the young adult stage.

  10. Development of verbal short-term memory and working memory in children with epilepsy: Developmental delay and impact of time-related variables. A cross-sectional study.

    Science.gov (United States)

    van Iterson, Loretta; de Jong, Peter F

    2018-01-01

    While short-term memory (STM) and working memory (WM) are understood as being crucial for learning, and children with epilepsy often experience learning difficulties, little is known about the age-related development of memory span tasks in children with epilepsy. Short-term memory and WM, operationalized as digit span forwards (DSF) or digit span backwards (DSB), respectively, were studied. Participants were 314 children with epilepsy and 327 typically developing children in ages between 5 and 15years and full scale intelligence quotient (FS-IQ)≥75. Cross-sectional analyses of the data were done with analyses of variance and analyses of covariance ((M)ANCOVAs) and generalized linear analyses. The analyses revealed that STM problems in epilepsy were mediated by age-related gains in WM as well as by differences in IQ. Working memory developed at a quick pace in the younger children, the pace slowed down to some extent in the later primary school years and resumed again later on. Working memory problems prevailed in epilepsy, independent of IQ and development of STM. Timing of the epilepsy in terms of age at onset and duration determined memory development. The youngest children with epilepsy showed age-appropriate development in STM but were the most vulnerable in terms of WM development. Later in the course of the epilepsy, the WM problems of the young children attenuated. In later onset epilepsy, WM problems were smaller but persisted over time. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Keeping track of time: evidence for episodic-like memory in great apes.

    Science.gov (United States)

    Martin-Ordas, Gema; Haun, Daniel; Colmenares, Fernando; Call, Josep

    2010-03-01

    Episodic memory, as defined by Tulving, can be described in terms of behavioural elements (what, where and when information) but it is also accompanied by an awareness of one's past (chronesthesia) and a subjective conscious experience (autonoetic awareness). Recent experiments have shown that corvids and rodents recall the where, what and when of an event. This capability has been called episodic-like memory because it only fulfils the behavioural criteria for episodic memory. We tested seven chimpanzees, three orangutans and two bonobos of various ages by adapting two paradigms, originally developed by Clayton and colleagues to test scrub jays. In Experiment 1, subjects were fed preferred but perishable food (frozen juice) and less preferred but non-perishable food (grape). After the food items were hidden, subjects could choose one of them either after 5 min or 1 h. The frozen juice was still available after 5 min but melted after 1 h and became unobtainable. Apes chose the frozen juice significantly more after 5 min and the grape after 1 h. In Experiment 2, subjects faced two baiting events happening at different times, yet they formed an integrated memory for the location and time of the baiting event for particular food items. We also included a memory task that required no temporal encoding. Our results showed that apes remember in an integrated fashion what, where and when (i.e., how long ago) an event happened; that is, apes distinguished between different events in which the same food items were hidden in different places at different times. The temporal control of their choices was not dependent on the familiarity of the platforms where the food was hidden. Chimpanzees' and bonobos' performance in the temporal encoding task was age-dependent, following an inverted U-shaped distribution. The age had no effect on the performance of the subjects in the task that required no temporal encoding.

  12. The timing of differentiation of adult hippocampal neurons is crucial for spatial memory.

    Directory of Open Access Journals (Sweden)

    Stefano Farioli-Vecchioli

    2008-10-01

    Full Text Available Adult neurogenesis in the dentate gyrus plays a critical role in hippocampus-dependent spatial learning. It remains unknown, however, how new neurons become functionally integrated into spatial circuits and contribute to hippocampus-mediated forms of learning and memory. To investigate these issues, we used a mouse model in which the differentiation of adult-generated dentate gyrus neurons can be anticipated by conditionally expressing the pro-differentiative gene PC3 (Tis21/BTG2 in nestin-positive progenitor cells. In contrast to previous studies that affected the number of newly generated neurons, this strategy selectively changes their timing of differentiation. New, adult-generated dentate gyrus progenitors, in which the PC3 transgene was expressed, showed accelerated differentiation and significantly reduced dendritic arborization and spine density. Functionally, this genetic manipulation specifically affected different hippocampus-dependent learning and memory tasks, including contextual fear conditioning, and selectively reduced synaptic plasticity in the dentate gyrus. Morphological and functional analyses of hippocampal neurons at different stages of differentiation, following transgene activation within defined time-windows, revealed that the new, adult-generated neurons up to 3-4 weeks of age are required not only to acquire new spatial information but also to use previously consolidated memories. Thus, the correct unwinding of these key memory functions, which can be an expression of the ability of adult-generated neurons to link subsequent events in memory circuits, is critically dependent on the correct timing of the initial stages of neuron maturation and connection to existing circuits.

  13. Correlated electron dynamics and memory in time-dependent density functional theory

    International Nuclear Information System (INIS)

    Thiele, Mark

    2009-01-01

    Time-dependent density functional theory (TDDFT) is an exact reformulation of the time-dependent many-electron Schroedinger equation, where the problem of many interacting electrons is mapped onto the Kohn-Sham system of noninteracting particles which reproduces the exact electronic density. In the Kohn-Sham system all non-classical many-body effects are incorporated in the exchange-correlation potential which is in general unknown and needs to be approximated. It is the goal of this thesis to investigate the connection between memory effects and correlated electron dynamics in strong and weak fields. To this end one-dimensional two-electron singlet systems are studied. At the same time these systems include the onedimensional helium atom model, which is an established system to investigate the crucial effects of correlated electron dynamics in external fields. The studies presented in this thesis show that memory effects are negligible for typical strong field processes. Here the approximation of the spatial nonlocality is of primary importance. For the photoabsorption spectra on the other hand the neglect of memory effects leads to qualitative and quantitative errors, which are shown to be connected to transitions of double excitation character. To develop a better understanding of the conditions under which memory effects become important quantum fluid dynamics has been found to be especially suitable. It represents a further exact reformulation of the quantum mechanic many-body problem which is based on hydrodynamic quantities such as density and velocity. Memory effects are shown to be important whenever the velocity field develops strong gradients and dissipative effects contribute. (orig.)

  14. Correlated electron dynamics and memory in time-dependent density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Thiele, Mark

    2009-07-28

    Time-dependent density functional theory (TDDFT) is an exact reformulation of the time-dependent many-electron Schroedinger equation, where the problem of many interacting electrons is mapped onto the Kohn-Sham system of noninteracting particles which reproduces the exact electronic density. In the Kohn-Sham system all non-classical many-body effects are incorporated in the exchange-correlation potential which is in general unknown and needs to be approximated. It is the goal of this thesis to investigate the connection between memory effects and correlated electron dynamics in strong and weak fields. To this end one-dimensional two-electron singlet systems are studied. At the same time these systems include the onedimensional helium atom model, which is an established system to investigate the crucial effects of correlated electron dynamics in external fields. The studies presented in this thesis show that memory effects are negligible for typical strong field processes. Here the approximation of the spatial nonlocality is of primary importance. For the photoabsorption spectra on the other hand the neglect of memory effects leads to qualitative and quantitative errors, which are shown to be connected to transitions of double excitation character. To develop a better understanding of the conditions under which memory effects become important quantum fluid dynamics has been found to be especially suitable. It represents a further exact reformulation of the quantum mechanic many-body problem which is based on hydrodynamic quantities such as density and velocity. Memory effects are shown to be important whenever the velocity field develops strong gradients and dissipative effects contribute. (orig.)

  15. Impact of time and space evolution of ion tracks in nonvolatile memory cells approaching nanoscale

    International Nuclear Information System (INIS)

    Cellere, G.; Paccagnella, A.; Murat, M.; Barak, J.; Akkerman, A.; Harboe-Sorensen, R.; Virtanen, A.; Visconti, A.; Bonanomi, M.

    2010-01-01

    Swift heavy ions impacting on matter lose energy through the creation of dense tracks of charges. The study of the space and time evolution of energy exchange allows understanding the single event effects behavior in advanced microelectronic devices. In particular, the shrinking of minimum feature size of most advanced memory devices makes them very interesting test vehicles to study these effects since the device and the track dimensions are comparable; hence, measured effects are directly correlated with the time and space evolution of the energy release. In this work we are studying the time and space evolution of ion tracks by using advanced non volatile memories and Monte Carlo simulations. Experimental results are very well explained by the theoretical calculations.

  16. Falling out of time: enhanced memory for scenes presented at behaviorally irrelevant points in time in posttraumatic stress disorder (PTSD).

    Science.gov (United States)

    Levy-Gigi, Einat; Kéri, Szabolcs

    2012-01-01

    Spontaneous encoding of the visual environment depends on the behavioral relevance of the task performed simultaneously. If participants identify target letters or auditory tones while viewing a series of briefly presented natural and urban scenes, they demonstrate effective scene recognition only when a target, but not a behaviorally irrelevant distractor, appears together with the scene. Here, we show that individuals with posttraumatic stress disorder (PTSD), who witnessed the red sludge disaster in Hungary, show the opposite pattern of performance: enhanced recognition of scenes presented together with distractors and deficient recognition of scenes presented with targets. The recognition of trauma-related and neutral scenes was not different in individuals with PTSD. We found a positive correlation between memory for scenes presented with auditory distractors and re-experiencing symptoms (memory intrusions and flashbacks). These results suggest that abnormal encoding of visual scenes at behaviorally irrelevant events might be associated with intrusive experiences by disrupting the flow of time.

  17. Falling out of time: enhanced memory for scenes presented at behaviorally irrelevant points in time in posttraumatic stress disorder (PTSD.

    Directory of Open Access Journals (Sweden)

    Einat Levy-Gigi

    Full Text Available Spontaneous encoding of the visual environment depends on the behavioral relevance of the task performed simultaneously. If participants identify target letters or auditory tones while viewing a series of briefly presented natural and urban scenes, they demonstrate effective scene recognition only when a target, but not a behaviorally irrelevant distractor, appears together with the scene. Here, we show that individuals with posttraumatic stress disorder (PTSD, who witnessed the red sludge disaster in Hungary, show the opposite pattern of performance: enhanced recognition of scenes presented together with distractors and deficient recognition of scenes presented with targets. The recognition of trauma-related and neutral scenes was not different in individuals with PTSD. We found a positive correlation between memory for scenes presented with auditory distractors and re-experiencing symptoms (memory intrusions and flashbacks. These results suggest that abnormal encoding of visual scenes at behaviorally irrelevant events might be associated with intrusive experiences by disrupting the flow of time.

  18. Real-time stereo matching architecture based on 2D MRF model: a memory-efficient systolic array

    Directory of Open Access Journals (Sweden)

    Park Sungchan

    2011-01-01

    Full Text Available Abstract There is a growing need in computer vision applications for stereopsis, requiring not only accurate distance but also fast and compact physical implementation. Global energy minimization techniques provide remarkably precise results. But they suffer from huge computational complexity. One of the main challenges is to parallelize the iterative computation, solving the memory access problem between the big external memory and the massive processors. Remarkable memory saving can be obtained with our memory reduction scheme, and our new architecture is a systolic array. If we expand it into N's multiple chips in a cascaded manner, we can cope with various ranges of image resolutions. We have realized it using the FPGA technology. Our architecture records 19 times smaller memory than the global minimization technique, which is a principal step toward real-time chip implementation of the various iterative image processing algorithms with tiny and distributed memory resources like optical flow, image restoration, etc.

  19. Effect of the time-of-day of training on explicit memory.

    Science.gov (United States)

    Barbosa, F F; Albuquerque, F S

    2008-06-01

    Studies have shown a time-of-day of training effect on long-term explicit memory with a greater effect being shown in the afternoon than in the morning. However, these studies did not control the chronotype variable. Therefore, the purpose of this study was to assess if the time-of-day effect on explicit memory would continue if this variable were controlled, in addition to identifying the occurrence of a possible synchronic effect. A total of 68 undergraduates were classified as morning, intermediate, or afternoon types. The subjects listened to a list of 10 words during the training phase and immediately performed a recognition task, a procedure which they repeated twice. One week later, they underwent an unannounced recognition test. The target list and the distractor words were the same in all series. The subjects were allocated to two groups according to acquisition time: a morning group (N = 32), and an afternoon group (N = 36). One week later, some of the subjects in each of these groups were subjected to a test in the morning (N = 35) or in the afternoon (N = 33). The groups had similar chronotypes. Long-term explicit memory performance was not affected by test time-of-day or by chronotype. However, there was a training time-of-day effect [F (1,56) = 53.667; P = 0.009] with better performance for those who trained in the afternoon. Our data indicated that the advantage of training in the afternoon for long-term memory performance does not depend on chronotype and also that this performance is not affected by the synchronic effect.

  20. Effect of the time-of-day of training on explicit memory

    Directory of Open Access Journals (Sweden)

    F.F. Barbosa

    2008-06-01

    Full Text Available Studies have shown a time-of-day of training effect on long-term explicit memory with a greater effect being shown in the afternoon than in the morning. However, these studies did not control the chronotype variable. Therefore, the purpose of this study was to assess if the time-of-day effect on explicit memory would continue if this variable were controlled, in addition to identifying the occurrence of a possible synchronic effect. A total of 68 undergraduates were classified as morning, intermediate, or afternoon types. The subjects listened to a list of 10 words during the training phase and immediately performed a recognition task, a procedure which they repeated twice. One week later, they underwent an unannounced recognition test. The target list and the distractor words were the same in all series. The subjects were allocated to two groups according to acquisition time: a morning group (N = 32, and an afternoon group (N = 36. One week later, some of the subjects in each of these groups were subjected to a test in the morning (N = 35 or in the afternoon (N = 33. The groups had similar chronotypes. Long-term explicit memory performance was not affected by test time-of-day or by chronotype. However, there was a training time-of-day effect [F (1,56 = 53.667; P = 0.009] with better performance for those who trained in the afternoon. Our data indicated that the advantage of training in the afternoon for long-term memory performance does not depend on chronotype and also that this performance is not affected by the synchronic effect.

  1. Case study on iron in mental development - in memory of John Beard (1947-2009)

    NARCIS (Netherlands)

    Osendarp, S.J.M.; Murray-Kolb, L.E.; Black, M.M.

    2010-01-01

    Iron deficiency (ID) anemia is associated with poor neurocognitive development in infants and children. Depending on the stage of development at the time of deficiency, these adverse effects may be reversible. Recent investigations using sensitive measurements have confirmed that the deposition of

  2. Effect of Time Delay on Recognition Memory for Pictures: The Modulatory Role of Emotion

    Science.gov (United States)

    Wang, Bo

    2014-01-01

    This study investigated the modulatory role of emotion in the effect of time delay on recognition memory for pictures. Participants viewed neutral, positive and negative pictures, and took a recognition memory test 5 minutes, 24 hours, or 1 week after learning. The findings are: 1) For neutral, positive and negative pictures, overall recognition accuracy in the 5-min delay did not significantly differ from that in the 24-h delay. For neutral and positive pictures, overall recognition accuracy in the 1-week delay was lower than in the 24-h delay; for negative pictures, overall recognition in the 24-h and 1-week delay did not significantly differ. Therefore negative emotion modulates the effect of time delay on recognition memory, maintaining retention of overall recognition accuracy only within a certain frame of time. 2) For the three types of pictures, recollection and familiarity in the 5-min delay did not significantly differ from that in the 24-h and the 1-week delay. Thus emotion does not appear to modulate the effect of time delay on recollection and familiarity. However, recollection in the 24-h delay was higher than in the 1-week delay, whereas familiarity in the 24-h delay was lower than in the 1-week delay. PMID:24971457

  3. Real-world-time simulation of memory consolidation in a large-scale cerebellar model

    Directory of Open Access Journals (Sweden)

    Masato eGosui

    2016-03-01

    Full Text Available We report development of a large-scale spiking network model of thecerebellum composed of more than 1 million neurons. The model isimplemented on graphics processing units (GPUs, which are dedicatedhardware for parallel computing. Using 4 GPUs simultaneously, we achieve realtime simulation, in which computer simulation ofcerebellar activity for 1 sec completes within 1 sec in thereal-world time, with temporal resolution of 1 msec.This allows us to carry out a very long-term computer simulationof cerebellar activity in a practical time with millisecond temporalresolution. Using the model, we carry out computer simulationof long-term gain adaptation of optokinetic response (OKR eye movementsfor 5 days aimed to study the neural mechanisms of posttraining memoryconsolidation. The simulation results are consistent with animal experimentsand our theory of posttraining memory consolidation. These resultssuggest that realtime computing provides a useful means to studya very slow neural process such as memory consolidation in the brain.

  4. Involuntary memories of emotional scenes: The effects of cue discriminability and emotion over time

    DEFF Research Database (Denmark)

    Staugaard, Søren Risløv; Berntsen, Dorthe

    2014-01-01

    a range of clinical disorders, there is no broadly agreed upon explanation of their underlying mechanisms and no successful experimental simulations of their retrieval. In a series of experiments, we experimentally manipulated the activation of involuntary episodic memories for emotional and neutral...... scenes and predicted their activation on the basis of manipulations carried out at encoding and retrieval. Our findings suggest that the interplay between cue discriminability at the time of retrieval and emotional arousal at the time of encoding are crucial for explaining intrusive memories following...... negative events. While cue distinctiveness is important directly following encoding of the scenes, emotional intensity influences retrieval after delays of 24 hr and 1 week. Voluntary remembering follows the same pattern as involuntary remembering. Our results suggest an explanatory model of intrusive...

  5. Memory effect in silicon time-gated single-photon avalanche diodes

    International Nuclear Information System (INIS)

    Dalla Mora, A.; Contini, D.; Di Sieno, L.; Tosi, A.; Boso, G.; Villa, F.; Pifferi, A.

    2015-01-01

    We present a comprehensive characterization of the memory effect arising in thin-junction silicon Single-Photon Avalanche Diodes (SPADs) when exposed to strong illumination. This partially unknown afterpulsing-like noise represents the main limiting factor when time-gated acquisitions are exploited to increase the measurement dynamic range of very fast (picosecond scale) and faint (single-photon) optical signals following a strong stray one. We report the dependences of this unwelcome signal-related noise on photon wavelength, detector temperature, and biasing conditions. Our results suggest that this so-called “memory effect” is generated in the deep regions of the detector, well below the depleted region, and its contribution on detector response is visible only when time-gated SPADs are exploited to reject a strong burst of photons

  6. Memory effect in silicon time-gated single-photon avalanche diodes

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Mora, A.; Contini, D., E-mail: davide.contini@polimi.it; Di Sieno, L. [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Tosi, A.; Boso, G.; Villa, F. [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Pifferi, A. [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); CNR, Istituto di Fotonica e Nanotecnologie, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy)

    2015-03-21

    We present a comprehensive characterization of the memory effect arising in thin-junction silicon Single-Photon Avalanche Diodes (SPADs) when exposed to strong illumination. This partially unknown afterpulsing-like noise represents the main limiting factor when time-gated acquisitions are exploited to increase the measurement dynamic range of very fast (picosecond scale) and faint (single-photon) optical signals following a strong stray one. We report the dependences of this unwelcome signal-related noise on photon wavelength, detector temperature, and biasing conditions. Our results suggest that this so-called “memory effect” is generated in the deep regions of the detector, well below the depleted region, and its contribution on detector response is visible only when time-gated SPADs are exploited to reject a strong burst of photons.

  7. Speech timing and working memory in profoundly deaf children after cochlear implantation

    OpenAIRE

    Burkholder, Rose A.; Pisoni, David B.

    2003-01-01

    Thirty-seven profoundly deaf children between 8- and 9-years-old with cochlear implants and a comparison group of normal-hearing children were studied to measure speaking rates, digit spans, and speech timing during digit span recall. The deaf children displayed longer sentence durations and pauses during recall and shorter digit spans compared to the normal-hearing children. Articulation rates, measured from sentence durations, were strongly correlated with immediate memory span in both norm...

  8. Time-based forgetting in visual working memory reflects temporal distinctiveness, not decay

    OpenAIRE

    Souza Alessandra S.; Oberauer Klaus

    2015-01-01

    Is forgetting from working memory (WM) better explained by decay or interference? The answer to this question is the topic of an ongoing debate. Recently a number of studies showed that performance in tests of visual WM declines with an increasing unfilled retention interval. This finding was interpreted as revealing decay. Alternatively it can be explained by interference theories as an effect of temporal distinctiveness. According to decay theories forgetting depends on the absolute time el...

  9. Reliable Memory Feedback Design for a Class of Nonlinear Fuzzy Systems with Time-varying Delay

    Institute of Scientific and Technical Information of China (English)

    You-Qing Wang; Dong-Hua Zhou; Li-Heng Liu

    2007-01-01

    This paper is concerned with the robust reliable memory controller design for a class of fuzzy uncertain systems with time-varying delay. The system under consideration is more general than those in other existent works. The controller, which is dependent on the magnitudes and derivative of the delay, is proposed in terms of linear matrix inequality (LMI). The closed-loop system is asymptotically stable for all admissible uncertainties as well as actuator faults. A numerical example is presented for illustration.

  10. On exponential stability of bidirectional associative memory neural networks with time-varying delays

    International Nuclear Information System (INIS)

    Park, Ju H.; Lee, S.M.; Kwon, O.M.

    2009-01-01

    For bidirectional associate memory neural networks with time-varying delays, the problems of determining the exponential stability and estimating the exponential convergence rate are investigated by employing the Lyapunov functional method and linear matrix inequality (LMI) technique. A novel criterion for the stability, which give information on the delay-dependent property, is derived. A numerical example is given to demonstrate the effectiveness of the obtained results.

  11. Global asymptotic stability of hybrid bidirectional associative memory neural networks with time delays

    International Nuclear Information System (INIS)

    Arik, Sabri

    2006-01-01

    This Letter presents a sufficient condition for the existence, uniqueness and global asymptotic stability of the equilibrium point for bidirectional associative memory (BAM) neural networks with distributed time delays. The results impose constraint conditions on the network parameters of neural system independently of the delay parameter, and they are applicable to all bounded continuous non-monotonic neuron activation functions. The results are also compared with the previous results derived in the literature

  12. Global robust stability of bidirectional associative memory neural networks with multiple time delays.

    Science.gov (United States)

    Senan, Sibel; Arik, Sabri

    2007-10-01

    This correspondence presents a sufficient condition for the existence, uniqueness, and global robust asymptotic stability of the equilibrium point for bidirectional associative memory neural networks with discrete time delays. The results impose constraint conditions on the network parameters of the neural system independently of the delay parameter, and they are applicable to all bounded continuous nonmonotonic neuron activation functions. Some numerical examples are given to compare our results with the previous robust stability results derived in the literature.

  13. Global asymptotic stability of hybrid bidirectional associative memory neural networks with time delays

    Science.gov (United States)

    Arik, Sabri

    2006-02-01

    This Letter presents a sufficient condition for the existence, uniqueness and global asymptotic stability of the equilibrium point for bidirectional associative memory (BAM) neural networks with distributed time delays. The results impose constraint conditions on the network parameters of neural system independently of the delay parameter, and they are applicable to all bounded continuous non-monotonic neuron activation functions. The results are also compared with the previous results derived in the literature.

  14. No Clear Association between Impaired Short-Term or Working Memory Storage and Time Reproduction Capacity in Adult ADHD Patients.

    Science.gov (United States)

    Mette, Christian; Grabemann, Marco; Zimmermann, Marco; Strunz, Laura; Scherbaum, Norbert; Wiltfang, Jens; Kis, Bernhard

    2015-01-01

    Altered time reproduction is exhibited by patients with adult attention deficit hyperactivity disorder (ADHD). It remains unclear whether memory capacity influences the ability of adults with ADHD to reproduce time intervals. We conducted a behavioral study on 30 ADHD patients who were medicated with methylphenidate, 29 unmedicated adult ADHD patients and 32 healthy controls (HCs). We assessed time reproduction using six time intervals (1 s, 4 s, 6 s, 10 s, 24 s and 60 s) and assessed memory performance using the Wechsler memory scale. The patients with ADHD exhibited lower memory performance scores than the HCs. No significant differences in the raw scores for any of the time intervals (p > .05), with the exception of the variability at the short time intervals (1 s, 4 s and 6 s) (p memory performance (p > .05). We detected no findings indicating that working memory might influence time reproduction in adult patients with ADHD. Therefore, further studies concerning time reproduction and memory capacity among adult patients with ADHD must be performed to verify and replicate the present findings.

  15. Subjective responses of mental workload during real time driving: A pilot field study

    Science.gov (United States)

    Rahman, N. I. A.; Dawal, S. Z. M.; Yusoff, N.

    2017-06-01

    This study evaluated drivers’ mental workload in real time driving to identify the driving situation’s complexity influences in an attempt to further design on a complete experimental study. Three driving settings were prepared: Session A (simple situation); Session B (moderately complex situation); Session C (very complex situation). To determine the mental workload, the NASA-Task Load Index (TLX) was administered to four drivers after each experimental driving session. The results showed that the Own Performance (OP) was the highest for session A (highway), while Physical Demand (PD) recorded the highest mean workload score across the session B (rural road) and C (city road). Based on the overall results of the study, it can be concluded that the highway is less demanding compared to rural and city road. It can be highlighted in this study that in the rural and city road driving situation, the timing must be set correctly to assure the relevant traffic density. Thus, the sensitivity of the timing must be considered in the future experiment. A larger number of experience drivers must be used in evaluating the driving situations to provide results that can be used to draw more realistic experiments and conclusions.

  16. Prescribed journeys through life: Cultural differences in mental time travel between Middle Easterners and Scandinavians.

    Science.gov (United States)

    Ottsen, Christina Lundsgaard; Berntsen, Dorthe

    2015-12-01

    Mental time travel is the ability to remember past events and imagine future events. Here, 124 Middle Easterners and 128 Scandinavians generated important past and future events. These different societies present a unique opportunity to examine effects of culture. Findings indicate stronger influence of normative schemas and greater use of mental time travel to teach, inform and direct behaviour in the Middle East compared with Scandinavia. The Middle Easterners generated more events that corresponded to their cultural life script and that contained religious words, whereas the Scandinavians reported events with a more positive mood impact. Effects of gender were mainly found in the Middle East. Main effects of time orientation largely replicated recent findings showing that simulation of future and past events are not necessarily parallel processes. In accordance with the notion that future simulations rely on schema-based construction, important future events showed a higher overlap with life script events than past events in both cultures. In general, cross-cultural discrepancies were larger in future compared with past events. Notably, the high focus in the Middle East on sharing future events to give cultural guidance is consistent with the increased adherence to normative scripts found in this culture. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Associations between parents? subjective time pressure and mental health problems among children in the Nordic countries: a population based study

    OpenAIRE

    Gunnarsdottir, Hrafnhildur; Bjereld, Ylva; Hensing, Gunnel; Petzold, Max; Povlsen, Lene

    2015-01-01

    Background The home, the family and the parents represent a context of everyday life that is important for child health and development, with parent-child relationships highlighted as crucial for children?s mental health. Time pressure is an emerging feature of modern societies and previous studies indicates that parents with children living at home experience time pressure to a greater extent than people with no children living at home. Previous studies of children?s mental health in relatio...

  18. Recurrent Neural Network For Forecasting Time Series With Long Memory Pattern

    Science.gov (United States)

    Walid; Alamsyah

    2017-04-01

    Recurrent Neural Network as one of the hybrid models are often used to predict and estimate the issues related to electricity, can be used to describe the cause of the swelling of electrical load which experienced by PLN. In this research will be developed RNN forecasting procedures at the time series with long memory patterns. Considering the application is the national electrical load which of course has a different trend with the condition of the electrical load in any country. This research produces the algorithm of time series forecasting which has long memory pattern using E-RNN after this referred to the algorithm of integrated fractional recurrent neural networks (FIRNN).The prediction results of long memory time series using models Fractional Integrated Recurrent Neural Network (FIRNN) showed that the model with the selection of data difference in the range of [-1,1] and the model of Fractional Integrated Recurrent Neural Network (FIRNN) (24,6,1) provides the smallest MSE value, which is 0.00149684.

  19. The time course of activation of object shape and shape+colour representations during memory retrieval.

    Directory of Open Access Journals (Sweden)

    Toby J Lloyd-Jones

    Full Text Available Little is known about the timing of activating memory for objects and their associated perceptual properties, such as colour, and yet this is important for theories of human cognition. We investigated the time course associated with early cognitive processes related to the activation of object shape and object shape+colour representations respectively, during memory retrieval as assessed by repetition priming in an event-related potential (ERP study. The main findings were as follows: (1 we identified a unique early modulation of mean ERP amplitude during the N1 that was associated with the activation of object shape independently of colour; (2 we also found a subsequent early P2 modulation of mean amplitude over the same electrode clusters associated with the activation of object shape+colour representations; (3 these findings were apparent across both familiar (i.e., correctly coloured - yellow banana and novel (i.e., incorrectly coloured - blue strawberry objects; and (4 neither of the modulations of mean ERP amplitude were evident during the P3. Together the findings delineate the timing of object shape and colour memory systems and support the notion that perceptual representations of object shape mediate the retrieval of temporary shape+colour representations for familiar and novel objects.

  20. The time course of activation of object shape and shape+colour representations during memory retrieval.

    Science.gov (United States)

    Lloyd-Jones, Toby J; Roberts, Mark V; Leek, E Charles; Fouquet, Nathalie C; Truchanowicz, Ewa G

    2012-01-01

    Little is known about the timing of activating memory for objects and their associated perceptual properties, such as colour, and yet this is important for theories of human cognition. We investigated the time course associated with early cognitive processes related to the activation of object shape and object shape+colour representations respectively, during memory retrieval as assessed by repetition priming in an event-related potential (ERP) study. The main findings were as follows: (1) we identified a unique early modulation of mean ERP amplitude during the N1 that was associated with the activation of object shape independently of colour; (2) we also found a subsequent early P2 modulation of mean amplitude over the same electrode clusters associated with the activation of object shape+colour representations; (3) these findings were apparent across both familiar (i.e., correctly coloured - yellow banana) and novel (i.e., incorrectly coloured - blue strawberry) objects; and (4) neither of the modulations of mean ERP amplitude were evident during the P3. Together the findings delineate the timing of object shape and colour memory systems and support the notion that perceptual representations of object shape mediate the retrieval of temporary shape+colour representations for familiar and novel objects.

  1. 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.

  2. 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.

  3. Discrete-Slots Models of Visual Working-Memory Response Times

    Science.gov (United States)

    Donkin, Christopher; Nosofsky, Robert M.; Gold, Jason M.; Shiffrin, Richard M.

    2014-01-01

    Much recent research has aimed to establish whether visual working memory (WM) is better characterized by a limited number of discrete all-or-none slots or by a continuous sharing of memory resources. To date, however, researchers have not considered the response-time (RT) predictions of discrete-slots versus shared-resources models. To complement the past research in this field, we formalize a family of mixed-state, discrete-slots models for explaining choice and RTs in tasks of visual WM change detection. In the tasks under investigation, a small set of visual items is presented, followed by a test item in 1 of the studied positions for which a change judgment must be made. According to the models, if the studied item in that position is retained in 1 of the discrete slots, then a memory-based evidence-accumulation process determines the choice and the RT; if the studied item in that position is missing, then a guessing-based accumulation process operates. Observed RT distributions are therefore theorized to arise as probabilistic mixtures of the memory-based and guessing distributions. We formalize an analogous set of continuous shared-resources models. The model classes are tested on individual subjects with both qualitative contrasts and quantitative fits to RT-distribution data. The discrete-slots models provide much better qualitative and quantitative accounts of the RT and choice data than do the shared-resources models, although there is some evidence for “slots plus resources” when memory set size is very small. PMID:24015956

  4. Acute immobilization stress following contextual fear conditioning reduces fear memory: timing is essential.

    Science.gov (United States)

    Uwaya, Akemi; Lee, Hyunjin; Park, Jonghyuk; Lee, Hosung; Muto, Junko; Nakajima, Sanae; Ohta, Shigeo; Mikami, Toshio

    2016-02-24

    Histone acetylation is regulated in response to stress and plays an important role in learning and memory. Chronic stress is known to deteriorate cognition, whereas acute stress facilitates memory formation. However, whether acute stress facilitates memory formation when it is applied after fear stimulation is not yet known. Therefore, this study aimed to investigate the effect of acute stress applied after fear training on memory formation, mRNA expression of brain-derived neurotrophic factor (BDNF), epigenetic regulation of BDNF expression, and corticosterone level in mice in vivo. Mice were subjected to acute immobilization stress for 30 min at 60 or 90 min after contextual fear conditioning training, and acetylation of histone 3 at lysine 14 (H3K14) and level of corticosterone were measured using western blot analysis and enzyme-linked immunosorbent assay (ELISA), respectively. A freezing behavior test was performed 24 h after training, and mRNA expression of BDNF was measured using real-time polymerase chain reactions. Different groups of mice were used for each test. Freezing behavior significantly decreased with the down-regulation of BDNF mRNA expression caused by acute immobilization stress at 60 min after fear conditioning training owing to the reduction of H3K14 acetylation. However, BDNF mRNA expression and H3K14 acetylation were not reduced in animals subjected to immobilization stress at 90 min after the training. Further, the corticosterone level was significantly high in mice subjected to immobilization stress at 60 min after the training. Acute immobilization stress for 30 min at 60 min after fear conditioning training impaired memory formation and reduced BDNF mRNA expression and H3K14 acetylation in the hippocampus of mice owing to the high level of corticosterone.

  5. Identifying deliberate attempts to fake memory impairment through the combined use of reaction time and event-related potential measures

    NARCIS (Netherlands)

    van Hooff, Johanna C.; Sargeant, Elizabeth; Foster, Jonathan K.; Schmand, Ben A.

    2009-01-01

    The central aim of this study was to evaluate the value of reaction time (RT) measures and event-related potentials (ERPs) for the assessment of simulated memory impairment. In two identical experiments (N = 24), healthy volunteers carried out an adapted version of the Amsterdam Short-Term Memory

  6. 75 FR 20564 - Dynamic Random Access Memory Semiconductors from the Republic of Korea: Extension of Time Limit...

    Science.gov (United States)

    2010-04-20

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-580-851] Dynamic Random Access Memory Semiconductors from the Republic of Korea: Extension of Time Limit for Preliminary Results of Countervailing Duty... access memory semiconductors from the Republic of Korea, covering the period January 1, 2008 through...

  7. Self-reported sitting time and physical activity: interactive associations with mental well-being and productivity in office employees.

    Science.gov (United States)

    Puig-Ribera, Anna; Martínez-Lemos, Iván; Giné-Garriga, Maria; González-Suárez, Ángel Manuel; Bort-Roig, Judit; Fortuño, Jesús; Muñoz-Ortiz, Laura; McKenna, Jim; Gilson, Nicholas D

    2015-01-31

    Little is known about how sitting time, alone or in combination with markers of physical activity (PA), influences mental well-being and work productivity. Given the need to develop workplace PA interventions that target employees' health related efficiency outcomes; this study examined the associations between self-reported sitting time, PA, mental well-being and work productivity in office employees. Descriptive cross-sectional study. Spanish university office employees (n = 557) completed a survey measuring socio-demographics, total and domain specific (work and travel) self-reported sitting time, PA (International Physical Activity Questionnaire short version), mental well-being (Warwick-Edinburg Mental Well-Being Scale) and work productivity (Work Limitations Questionnaire). Multivariate linear regression analyses determined associations between the main variables adjusted for gender, age, body mass index and occupation. PA levels (low, moderate and high) were introduced into the model to examine interactive associations. Higher volumes of PA were related to higher mental well-being, work productivity and spending less time sitting at work, throughout the working day and travelling during the week, including the weekends (p employees, higher sitting times on work days and occupational sitting were associated with decreased mental well-being (p employees. Employees' PA levels exerts different influences on the associations between sitting time, mental well-being and work productivity. The specific associations and the broad sweep of evidence in the current study suggest that workplace PA strategies to improve the mental well-being and productivity of all employees should focus on reducing sitting time alongside efforts to increase PA.

  8. Circadian timed episodic-like memory - a bee knows what to do when, and also where.

    Science.gov (United States)

    Pahl, Mario; Zhu, Hong; Pix, Waltraud; Tautz, Juergen; Zhang, Shaowu

    2007-10-01

    This study investigates how the colour, shape and location of patterns could be memorized within a time frame. Bees were trained to visit two Y-mazes, one of which presented yellow vertical (rewarded) versus horizontal (non-rewarded) gratings at one site in the morning, while another presented blue horizontal (rewarded) versus vertical (non-rewarded) gratings at another site in the afternoon. The bees could perform well in the learning tests and various transfer tests, in which (i) all contextual cues from the learning test were present; (ii) the colour cues of the visual patterns were removed, but the location cue, the orientation of the visual patterns and the temporal cue still existed; (iii) the location cue was removed, but other contextual cues, i.e. the colour and orientation of the visual patterns and the temporal cue still existed; (iv) the location cue and the orientation cue of the visual patterns were removed, but the colour cue and temporal cue still existed; (v) the location cue, and the colour cue of the visual patterns were removed, but the orientation cue and the temporal cue still existed. The results reveal that the honeybee can recall the memory of the correct visual patterns by using spatial and/or temporal information. The relative importance of different contextual cues is compared and discussed. The bees' ability to integrate elements of circadian time, place and visual stimuli is akin to episodic-like memory; we have therefore named this kind of memory circadian timed episodic-like memory.

  9. Shorter time since inflammatory bowel disease diagnosis in children is associated with lower mental health in parents.

    Science.gov (United States)

    Werner, H; Braegger, Cp; Buehr, P; Koller, R; Nydegger, A; Spalinger, J; Heyland, K; Schibli, S; Landolt, Ma

    2015-01-01

    This study assessed the mental health of parents of children with inflammatory bowel disease (IBD), compared their mental health with age-matched and gender-matched references and examined parental and child predictors for mental health problems. A total of 125 mothers and 106 fathers of 125 children with active and inactive IBD from the Swiss IBD multicentre cohort study were included. Parental mental health was assessed by the Symptom Checklist 27 and child behaviour problems by the Strengths and Difficulties Questionnaire. Child medical data were extracted from hospital records. While the mothers reported lower mental health, the fathers' mental health was similar, or even better, than in age-matched and gender-matched community controls. In both parents, shorter time since the child's diagnosis was associated with poorer mental health. In addition, the presence of their own IBD diagnosis and child behaviour problems predicted maternal mental health problems. Parents of children with IBD may need professional support when their child is diagnosed, to mitigate distress. This, in turn, may help the child to adjust better to IBD. Particular attention should be paid to mothers who have their own IBD diagnosis and whose children display behaviour problems. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  10. Associations between parents' subjective time pressure and mental health problems among children in the Nordic countries: a population based study.

    Science.gov (United States)

    Gunnarsdottir, Hrafnhildur; Bjereld, Ylva; Hensing, Gunnel; Petzold, Max; Povlsen, Lene

    2015-04-10

    The home, the family and the parents represent a context of everyday life that is important for child health and development, with parent-child relationships highlighted as crucial for children's mental health. Time pressure is an emerging feature of modern societies and previous studies indicates that parents with children living at home experience time pressure to a greater extent than people with no children living at home. Previous studies of children's mental health in relation to parents' time pressure are lacking. Hence, the purpose of this study was to examine the association between parents' subjective time pressure and mental health problems among children in the Nordic countries as well as potential disparities between boys and girls in different age groups. 4592 children, aged 4-16 from Denmark, Finland, Norway and Sweden, participating in the 2011 version of the NordChild study, were included. The Strength and Difficulties Questionnaire was used to measure children's mental health and associations to parents' time pressure were assessed by multiple logistic regression analysis. Among children of parents experiencing time pressure, 18.6% had mental health problems compared to 10.1% among children of parents experiencing time pressure not or sometimes. The odds of mental health problems were higher among both boys (OR 1.80 95% CI 1.32-2.46) and girls (OR 1.95 95% CI 1.42-2.66) if their parents experienced time pressure when adjusted for financial stress. The highest prevalence of mental health problems in the case of parental time pressure was found among girls 13-16 years old (23.6%) and the lowest prevalence was found among boys 13-16 years old (10.7%). In this study an association between parents' subjective time pressure and increased mental health problems among children was found. Given that time pressure is a growing feature of modern societies, the results might contribute to an explanation as to mental health problems are common among children

  11. Timing of presentation and nature of stimuli determine retroactive interference with social recognition memory in mice.

    Science.gov (United States)

    Perna, Judith Camats; Wotjak, Carsten T; Stork, Oliver; Engelmann, Mario

    2015-05-01

    The present study was designed to further investigate the nature of stimuli and the timing of their presentation, which can induce retroactive interference with social recognition memory in mice. In accordance with our previous observations, confrontation with an unfamiliar conspecific juvenile 3h and 6h, but not 22 h, after the initial learning session resulted in retroactive interference. The same effect was observed with the exposure to both enantiomers of the monomolecular odour carvone, and with a novel object. Exposure to a loud tone (12 KHz, 90 dB) caused retroactive interference at 6h, but not 3h and 22 h, after sampling. Our data show that retroactive interference of social recognition memory can be induced by exposing the experimental subjects to the defined stimuli presented <22 h after learning in their home cage. The distinct interference triggered by the tone presentation at 6h after sampling may be linked to the intrinsic aversiveness of the loud tone and suggests that at this time point memory consolidation is particularly sensitive to stress. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. MASMA: a versatile multifunctional unit (gated window amplifier, analog memory, and height-to-time converter)

    International Nuclear Information System (INIS)

    Goursky, V.; Thenes, P.

    1969-01-01

    This multipurpose unit is designed to accomplish one of the following functions: - gated window amplifier, - Analog memory and - Amplitude-to-time converter. The first function is mainly devoted to improve the poor resolution of pulse-height analyzers with a small number of channels. The analog memory, a new function in the standard range of plug-in modules, is capable of performing a number of operations: 1) fixed delay, or variable delay dependent on an external parameter (application to the analog processing of non-coincident pulses), 2) de-randomiser to increase the efficiency of the pulse height analysis in a spectrometry experiment, 3) linear multiplexer to allow an analyser to serve as many spectrometry devices as memory elements that it possesses. Associated with a coding scaler, this unit, if used as a amplitude-to-time converter, constitutes a Wilkinson A.D.C with a capability of 10 bits (or more) and with a 100 MHz clock frequency. (authors) [fr

  13. An individual differences approach to the suggestibility of memory over time.

    Science.gov (United States)

    Frost, Peter; Nussbaum, Gregory; Loconto, Taylor; Syke, Richard; Warren, Casey; Muise, Christina

    2013-04-01

    We examined how certain personality traits might relate to the formation of suggestive memory over time. We hypothesised that compliance and trust relate to initial acceptance of misinformation as memory, whereas fantasy proneness might relate to integration of misinformation into memory after later intervals (relative to the time of exposure to misinformation). Participants watched an excerpt from a movie--the simulated eyewitness event. They next answered a recall test that included embedded misinformation about the movie. Participants then answered a yes/no recognition test. A week later, participants answered a second yes/no recognition test about the movie (each yes/no recognition test included different questions). Before both recognition tests, participants were warned about the misinformation shown during recall and were asked to base their answer on the movie excerpt only. After completing the second recognition test, participants answered questions from the Neuroticism Extroversion Openness Personality Inventory-3 (McCrae, Costa, & Martin, 2005) and Creative Experiences Questionnaire (Merckelbach, Horselenberg, & Muris, 2001). While compliance correlated with misinformation effects immediately after exposure to misinformation, fantasy-prone personality accounted for more of the variability in false recognition rates than compliance after a 1-week interval.

  14. Generalized Fractional Processes with Long Memory and Time Dependent Volatility Revisited

    Directory of Open Access Journals (Sweden)

    M. Shelton Peiris

    2016-09-01

    Full Text Available In recent years, fractionally-differenced processes have received a great deal of attention due to their flexibility in financial applications with long-memory. This paper revisits the class of generalized fractionally-differenced processes generated by Gegenbauer polynomials and the ARMA structure (GARMA with both the long-memory and time-dependent innovation variance. We establish the existence and uniqueness of second-order solutions. We also extend this family with innovations to follow GARCH and stochastic volatility (SV. Under certain regularity conditions, we give asymptotic results for the approximate maximum likelihood estimator for the GARMA-GARCH model. We discuss a Monte Carlo likelihood method for the GARMA-SV model and investigate finite sample properties via Monte Carlo experiments. Finally, we illustrate the usefulness of this approach using monthly inflation rates for France, Japan and the United States.

  15. Fast Mapping Across Time: Memory Processes Support Children's Retention of Learned Words

    Directory of Open Access Journals (Sweden)

    Haley eVlach

    2012-02-01

    Full Text Available Children's remarkable ability to map linguistic labels to objects in the world is referred to as fast mapping. The current study examined children's (N = 216 and adults’ (N = 54 retention of fast-mapped words over time (immediately, after a 1 week delay, and after a 1 month delay. The fast mapping literature often characterizes children's retention of words as consistently high across timescales. However, the current study demonstrates that learners forget word mappings at a rapid rate. Moreover, these patterns of forgetting parallel forgetting functions of domain general memory processes. Memory processes are critical to children's word learning and the role of one such process, forgetting, is discussed in detail—forgetting supports both word mapping and the generalization of words and categories.

  16. Entrained rhythmic activities of neuronal ensembles as perceptual memory of time interval.

    Science.gov (United States)

    Sumbre, Germán; Muto, Akira; Baier, Herwig; Poo, Mu-ming

    2008-11-06

    The ability to process temporal information is fundamental to sensory perception, cognitive processing and motor behaviour of all living organisms, from amoebae to humans. Neural circuit mechanisms based on neuronal and synaptic properties have been shown to process temporal information over the range of tens of microseconds to hundreds of milliseconds. How neural circuits process temporal information in the range of seconds to minutes is much less understood. Studies of working memory in monkeys and rats have shown that neurons in the prefrontal cortex, the parietal cortex and the thalamus exhibit ramping activities that linearly correlate with the lapse of time until the end of a specific time interval of several seconds that the animal is trained to memorize. Many organisms can also memorize the time interval of rhythmic sensory stimuli in the timescale of seconds and can coordinate motor behaviour accordingly, for example, by keeping the rhythm after exposure to the beat of music. Here we report a form of rhythmic activity among specific neuronal ensembles in the zebrafish optic tectum, which retains the memory of the time interval (in the order of seconds) of repetitive sensory stimuli for a duration of up to approximately 20 s. After repetitive visual conditioning stimulation (CS) of zebrafish larvae, we observed rhythmic post-CS activities among specific tectal neuronal ensembles, with a regular interval that closely matched the CS. Visuomotor behaviour of the zebrafish larvae also showed regular post-CS repetitions at the entrained time interval that correlated with rhythmic neuronal ensemble activities in the tectum. Thus, rhythmic activities among specific neuronal ensembles may act as an adjustable 'metronome' for time intervals in the order of seconds, and serve as a mechanism for the short-term perceptual memory of rhythmic sensory experience.

  17. 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.

  18. The Interdependence of Advanced Cancer Patients' and Their Family Caregivers' Mental Health, Physical Health, and Self-Efficacy over Time.

    Science.gov (United States)

    Kershaw, Trace; Ellis, Katrina R; Yoon, Hyojin; Schafenacker, Ann; Katapodi, Maria; Northouse, Laurel

    2015-12-01

    The challenges of advanced cancer have health implications for patients and their family caregivers from diagnosis through end of life. The nature of the patient/caregiver experience suggests that their mental and physical health maybe interdependent, but limited empirical evidence exists. This study used social cognitive theory as a framework to investigate individual and interpersonal influences on patients' and their family caregivers' mental health, physical health, and self-efficacy as individuals to manage the challenges of advanced disease over time. Patients and caregivers (484 patient-caregiver dyads) completed surveys at baseline, 3 and 6 months. Longitudinal dyadic analysis techniques were used to examine (i)the influence that patients and caregivers had on their own mental health, physical health, and self-efficacy (actor effects)and (ii) the influence that they had on each other's health outcomes (partner effects). We also examined the influence of self-efficacy on mental and physical health over time. Consistent with our hypotheses, each person's mental health, physical health, and self-efficacy had significant effects on their own outcomes over time (actor effects). Patients and caregivers influenced one another's mental and physical health (partner effects), but not their self-efficacy. In addition, patients and caregivers with higher self-efficacy had better mental health, and their partners had better physical health. Patients' and caregivers' mental and physical health were interdependent. Each person's cancer-related self-efficacy influenced their own mental and physical health. However, a person's self-efficacy did not influence the other person's self-efficacy.

  19. The Interdependence of Advanced Cancer Patients’ and Their Family Caregivers’ Mental Health, Physical Health, and Self-Efficacy Over Time

    Science.gov (United States)

    Kershaw, Trace; Ellis, Katrina R.; Yoon, Hyojin; Schafenacker, Ann; Katapodi, Maria; Northouse, Laurel

    2016-01-01

    Background The challenges of advanced cancer have health implications for patients and their family caregivers from diagnosis through end-of-life. The nature of the patient/caregiver experience suggests that their mental and physical health may be interdependent, but limited empirical evidence exists. Purpose This study used Social Cognitive Theory as a framework to investigate individual and interpersonal influences on patients’ and their family caregivers’ mental health, physical health, and self-efficacy as individuals to manage the challenges of advanced disease over time. Methods Patients and caregivers (484 patient-caregiver dyads) completed surveys at baseline, 3 months and 6 months. Longitudinal dyadic analysis techniques were used to examine (i) the influence that patients and caregivers had on their own mental health, physical health, and self-efficacy (actor effects) and (ii) the influence that they had on each other’s health outcomes (partner effects). We also examined the influence of self-efficacy on mental and physical health over time. Results Consistent with our hypotheses, each person’s mental health, physical health, and self-efficacy had significant effects on their own outcomes over time (actor effects). Patients and caregivers influenced one another’s mental and physical health (partner effects), but not their self-efficacy. In addition, patients and caregivers with higher self-efficacy had better mental health, and their partners had better physical health. Conclusions Patient and caregiver mental and physical health were interdependent. Each person’s cancer-related self-efficacy influenced their own mental and physical health. However, a person’s self-efficacy did not influence the other person’s self-efficacy. PMID:26489843

  20. Time course effects of lithium administration on spatial memory acquisition and cholinergic marker expression in rats

    Directory of Open Access Journals (Sweden)

    M H Karimfar

    2009-08-01

    Full Text Available Background: The effects of chronic lithium exposure on spatial memory in rats remain controversial. In this study a time course of the effects of lithium, administered systemically, on spatial memory acquisition in Morris water maze was investigated. Material and Methods: Lithium (600 mg/L was administered to four groups of rats in their drinking water; the first group of animals received lithium for one week, the second group for two weeks, the third group for three weeks, and the fourth group for four weeks.  As controls, four groups of animals received only normal drinking water for the same period of time.  Toward the end of their lithium or water treatment, all animals were trained for four days; each day included one block and each block contained four trials.  Test trials were conducted 48 hrs after completion of the lithium treatment. Escape latency, traveled distance and swimming speed were evaluated during testing trials. Brain tissues from animals were processed according to the standard protocols for immunohistochemical analysis.  Results: Lithium treatment decreased escape latency and traveled distance, but not swimming speed, compared with controls, suggesting significant spatial memory acquisition enhancement by lithium. Quantitative analysis showed that lithium, particularly after four weeks of exposure, significantly increased the number and density of immunostained ChAT-containing (choline acetyltransferase neurons in the medial septal area in comparison with control groups.  There was also a significant correlation between the number of immunostained ChAT neurons and behavioral measures. Conclusion: These results suggest that chronic oral administration of lithium causes spatial memory acquisition improvement in rats and an increase in ChAT immunostaining levels in medial septal nuclei.

  1. On time-dependent diffusion coefficients arising from stochastic processes with memory

    Science.gov (United States)

    Carpio-Bernido, M. Victoria; Barredo, Wilson I.; Bernido, Christopher C.

    2017-08-01

    Time-dependent diffusion coefficients arise from anomalous diffusion encountered in many physical systems such as protein transport in cells. We compare these coefficients with those arising from analysis of stochastic processes with memory that go beyond fractional Brownian motion. Facilitated by the Hida white noise functional integral approach, diffusion propagators or probability density functions (pdf) are obtained and shown to be solutions of modified diffusion equations with time-dependent diffusion coefficients. This should be useful in the study of complex transport processes.

  2. Discrete-time bidirectional associative memory neural networks with variable delays

    International Nuclear Information System (INIS)

    Liang Jinling; Cao Jinde; Ho, Daniel W.C.

    2005-01-01

    Based on the linear matrix inequality (LMI), some sufficient conditions are presented in this Letter for the existence, uniqueness and global exponential stability of the equilibrium point of discrete-time bidirectional associative memory (BAM) neural networks with variable delays. Some of the stability criteria obtained in this Letter are delay-dependent, and some of them are delay-independent, they are less conservative than the ones reported so far in the literature. Furthermore, the results provide one more set of easily verified criteria for determining the exponential stability of discrete-time BAM neural networks

  3. Discrete-time bidirectional associative memory neural networks with variable delays

    Science.gov (United States)

    Liang, variable delays [rapid communication] J.; Cao, J.; Ho, D. W. C.

    2005-02-01

    Based on the linear matrix inequality (LMI), some sufficient conditions are presented in this Letter for the existence, uniqueness and global exponential stability of the equilibrium point of discrete-time bidirectional associative memory (BAM) neural networks with variable delays. Some of the stability criteria obtained in this Letter are delay-dependent, and some of them are delay-independent, they are less conservative than the ones reported so far in the literature. Furthermore, the results provide one more set of easily verified criteria for determining the exponential stability of discrete-time BAM neural networks.

  4. Urban Mind: Using Smartphone Technologies to Investigate the Impact of Nature on Mental Well-Being in Real Time

    Science.gov (United States)

    Bakolis, Ioannis; Hammoud, Ryan; Smythe, Michael; Gibbons, Johanna; Davidson, Neil; Tognin, Stefania

    2018-01-01

    Abstract Existing evidence on the beneficial effects of nature on mental health comes from studies using cross-sectional designs. We developed a smartphone-based tool (Urban Mind; www.urbanmind.info) to examine how exposure to natural features within the built environment affects mental well-being in real time. The tool was used to monitor 108 individuals who completed 3013 assessments over a 1-week period. Significant immediate and lagged associations with mental well-being were found for several natural features. These associations were stronger in people with higher trait impulsivity, a psychological measure of one's tendency to behave with little forethought or consideration of the consequences, which is indicative of a higher risk of developing mental-health issues. Our investigation suggests that the benefits of nature on mental well-being are time-lasting and interact with an individual's vulnerability to mental illness. These findings have potential implications from the perspectives of global mental health as well as urban planning and design. PMID:29599549

  5. Daily time management and influence of environmental factors on use of electronic planning devices in adults with mental disability.

    Science.gov (United States)

    Janeslätt, Gunnel; Lindstedt, Helena; Adolfsson, Päivi

    2015-01-01

    To describe daily time management in adults with and without mental disability and to examine differences in the level of their daily time management; to describe the possessions and use of electronic planning devices (EPDs) in activities and how environmental factors influence the use of EPDs in adults with mental disability. In a descriptive and cross-sectional design, 32 participants using EPDs and a matched comparison group of 32 healthy adults was recruited. Time-Self rating scale measuring daily time management was adapted for adults. A study specific questionnaire was applied to collect data on five ICF environmental factors. Rasch modelling, descriptive and non-parametric statistics were applied. Time-S has acceptable psychometric properties for use on adults with mental disability. People with mental disability and low level of daily time management who use advanced EPDs are more influenced by environmental factors. The study group perceived that encouragement and support from professionals as well as services influence their use of EPDs. Time-S can safely be used for people with mental disability. EPDs do not fully compensate the needs of the target-group. Prescribers need to give considerations to this and therefore they should be provided with more knowledge about this matter. Implications for Rehabilitation The Time-S can be applied for measuring daily time management in adults. Adults with mental disability provided with EPDs are not fully compensated in daily time management. Professional support and encouragement as well as backing from the services are important factors for the use of EPDs. Because the smart phones are not prescribed as assistive technology, the need for help from professionals to facilitate daily life is stressed. Therefore, the professionals should be provided with more knowledge about the use of EPDs.

  6. Parental Control of the Time Preadolescents Spend on Social Media: Links with Preadolescents' Social Media Appearance Comparisons and Mental Health.

    Science.gov (United States)

    Fardouly, Jasmine; Magson, Natasha R; Johnco, Carly J; Oar, Ella L; Rapee, Ronald M

    2018-07-01

    Time spent on social media and making online comparisons with others may influence users' mental health. This study examined links between parental control over the time their child spends on social media, preadolescents' time spent browsing social media, preadolescents' appearance comparisons on social media, and preadolescents' appearance satisfaction, depressive symptoms, and life satisfaction. Preadolescent social media users (N = 284, 49.1% female; aged 10-12) and one of their parents completed online surveys. Preadolescents, whose parents reported greater control over their child's time on social media, reported better mental health. This relationship was mediated by preadolescents spending less time browsing and making fewer appearance comparisons on social media. Parental control over time spent on social media may be associated with benefits for mental health among preadolescents.

  7. 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.

  8. Time course of scopolamine effect on memory consolidation and forgetting in rats.

    Science.gov (United States)

    Popović, Miroljub; Giménez de Béjar, Verónica; Popović, Natalija; Caballero-Bleda, María

    2015-02-01

    The effect of scopolamine on the consolidation and forgetting of emotional memory has not been completely elucidated yet. The aim of the present study was to investigate the time course of scopolamine effect on consolidation and forgetting of passive avoidance response. In a first experiment of the present study, we tested the effect of scopolamine (1mg/kg, i.p., immediately after acquisition), on 24h and 48h retention performance of the step-through passive avoidance task, in adult male Wistar rats. On the 24h retested trial, the latency of the passive avoidance response was significantly lower, while on the 48h retested trial it was significantly higher in scopolamine than in the saline-treated group. In a second experiment, we assessed the 24h time course of scopolamine (1mg/kg) effect on memory consolidation in passive avoidance task. We found that scopolamine administration only within the first six and half hours after acquisition improved memory consolidation in 48h retention performance. Finally, a third experiment was performed on the saline- and scopolamine-treated rats (given immediately after acquisition) that on the 48h retention test did not step through into the dark compartment during the cut-off time. These animals were retested weekly for up to first three months, and after that, every three months until the end of experiment (i.e., 15 months after acquisition). The passive avoidance response in the saline treated group lasted up to 6 weeks after acquisition, while in the scopolamine treated group 50% of animals conserved the initial level of passive avoidance response until the experiment end point. In conclusion, the present data suggest that (1) improving or impairment effect of scopolamine given in post-training periods depends on delay of retention trial, (2) memory consolidation process could be modify by scopolamine within first six and half hours after training and (3) scopolamine could delay forgetting of emotional memory. Copyright

  9. No Clear Association between Impaired Short-Term or Working Memory Storage and Time Reproduction Capacity in Adult ADHD Patients.

    Directory of Open Access Journals (Sweden)

    Christian Mette

    Full Text Available Altered time reproduction is exhibited by patients with adult attention deficit hyperactivity disorder (ADHD. It remains unclear whether memory capacity influences the ability of adults with ADHD to reproduce time intervals.We conducted a behavioral study on 30 ADHD patients who were medicated with methylphenidate, 29 unmedicated adult ADHD patients and 32 healthy controls (HCs. We assessed time reproduction using six time intervals (1 s, 4 s, 6 s, 10 s, 24 s and 60 s and assessed memory performance using the Wechsler memory scale.The patients with ADHD exhibited lower memory performance scores than the HCs. No significant differences in the raw scores for any of the time intervals (p > .05, with the exception of the variability at the short time intervals (1 s, 4 s and 6 s (p .05.We detected no findings indicating that working memory might influence time reproduction in adult patients with ADHD. Therefore, further studies concerning time reproduction and memory capacity among adult patients with ADHD must be performed to verify and replicate the present findings.

  10. Psychological detachment from work during non-work time: linear or curvilinear relations with mental health and work engagement?

    OpenAIRE

    SHIMAZU, Akihito; MATSUDAIRA, Ko; DE JONGE, Jan; TOSAKA, Naoya; WATANABE, Kazuhiro; TAKAHASHI, Masaya

    2016-01-01

    This study examined whether a higher level of psychological detachment during non-work time is associated with better employee mental health (Hypothesis 1), and examined whether psychological detachment has a curvilinear relation (inverted U-shaped pattern) with work engagement (Hypothesis 2). A large cross-sectional Internet survey was conducted among registered monitors of an Internet survey company in Japan. The questionnaire included scales for psychological detachment, employee mental he...

  11. Mental health impacts of flooding: a controlled interrupted time series analysis of prescribing data in England.

    Science.gov (United States)

    Milojevic, Ai; Armstrong, Ben; Wilkinson, Paul

    2017-10-01

    There is emerging evidence that people affected by flooding suffer adverse impacts on their mental well-being, mostly based on self-reports. We examined prescription records for drugs used in the management of common mental disorder among primary care practices located in the vicinity of recent large flood events in England, 2011-2014. A controlled interrupted time series analysis was conducted of the number of prescribing items for antidepressant drugs in the year before and after the flood onset. Pre-post changes were compared by distance of the practice from the inundated boundaries among 930 practices located within 10 km of a flood. After control for deprivation and population density, there was an increase of 0.59% (95% CI 0.24 to 0.94) prescriptions in the postflood year among practices located within 1 km of a flood over and above the change observed in the furthest distance band. The increase was greater in more deprived areas. This study suggests an increase in prescribed antidepressant drugs in the year after flooding in primary care practices close to recent major floods in England. The degree to which the increase is actually concentrated in those flooded can only be determined by more detailed linkage studies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Long Memory of Financial Time Series and Hidden Markov Models with Time-Varying Parameters

    DEFF Research Database (Denmark)

    Nystrup, Peter; Madsen, Henrik; Lindström, Erik

    2016-01-01

    Hidden Markov models are often used to model daily returns and to infer the hidden state of financial markets. Previous studies have found that the estimated models change over time, but the implications of the time-varying behavior have not been thoroughly examined. This paper presents an adaptive...... to reproduce with a hidden Markov model. Capturing the time-varying behavior of the parameters also leads to improved one-step density forecasts. Finally, it is shown that the forecasting performance of the estimated models can be further improved using local smoothing to forecast the parameter variations....

  13. Germanium nanoparticles grown at different deposition times for memory device applications

    International Nuclear Information System (INIS)

    Mederos, M.; Mestanza, S.N.M.; Lang, R.; Doi, I.; Diniz, J.A.

    2016-01-01

    In the present work, circular Metal-Oxide-Semiconductor capacitors with 200 μm of diameter and germanium (Ge) nanoparticles (NPs) embedded in the gate oxide are studied for memory applications. Optimal process parameters are investigated for Ge NPs growing by low pressure chemical vapor deposition at different deposition times. Photoluminescence measurements showed room-temperature size-dependent green-red region bands attributed to quantum confinement effects present in the NPs. High-frequency capacitance versus voltage measurements demonstrated the memory effects on the MOS structures due to the presence of Ge NPs in the gate oxide acting as discrete floating gates. Current versus voltage measurements confirmed the Fowler-Nordheim tunneling as the programming mechanism of the devices. - Highlights: • Ge nanoparticles with high density and uniforms sizes were obtained by LPCVD. • Room-temperature size-dependent bands of photoluminescence were observed. • MOS capacitors with Ge nanoparticles embedded in the oxide were fabricated. • Ge nanoparticles are the main responsible for the memory properties in the devices. • Fowler-Nordheim tunneling is the conduction mechanism observed on the devices.

  14. Germanium nanoparticles grown at different deposition times for memory device applications

    Energy Technology Data Exchange (ETDEWEB)

    Mederos, M., E-mail: melissa.mederos@gmail.com [Center for Semiconductor Components and Nanotechnology (CCSNano), University of Campinas (Unicamp), Rua João Pandia Calógeras 90, Campinas, CEP: 13083-870, São Paulo (Brazil); Mestanza, S.N.M. [Federal University of ABC (UFABC), Rua Santa Adélia 166, Bangu, Santo André, CEP: 09210-170, São Paulo (Brazil); Lang, R. [Institute of Science and Technology, Federal University of São Paulo (UNIFESP), Rua Talim, 330, São José dos Campos, CEP: 12231-280, São Paulo (Brazil); Doi, I.; Diniz, J.A. [Center for Semiconductor Components and Nanotechnology (CCSNano), University of Campinas (Unicamp), Rua João Pandia Calógeras 90, Campinas, CEP: 13083-870, São Paulo (Brazil); School of Electrical and Computer Engineering, University of Campinas (Unicamp), Av. Albert Einstein 400, Campinas, CEP: 13083-852, São Paulo (Brazil)

    2016-07-29

    In the present work, circular Metal-Oxide-Semiconductor capacitors with 200 μm of diameter and germanium (Ge) nanoparticles (NPs) embedded in the gate oxide are studied for memory applications. Optimal process parameters are investigated for Ge NPs growing by low pressure chemical vapor deposition at different deposition times. Photoluminescence measurements showed room-temperature size-dependent green-red region bands attributed to quantum confinement effects present in the NPs. High-frequency capacitance versus voltage measurements demonstrated the memory effects on the MOS structures due to the presence of Ge NPs in the gate oxide acting as discrete floating gates. Current versus voltage measurements confirmed the Fowler-Nordheim tunneling as the programming mechanism of the devices. - Highlights: • Ge nanoparticles with high density and uniforms sizes were obtained by LPCVD. • Room-temperature size-dependent bands of photoluminescence were observed. • MOS capacitors with Ge nanoparticles embedded in the oxide were fabricated. • Ge nanoparticles are the main responsible for the memory properties in the devices. • Fowler-Nordheim tunneling is the conduction mechanism observed on the devices.

  15. Response probability and response time: a straight line, the Tagging/Retagging interpretation of short term memory, an operational definition of meaningfulness and short term memory time decay and search time.

    Science.gov (United States)

    Tarnow, Eugen

    2008-12-01

    The functional relationship between correct response probability and response time is investigated in data sets from Rubin, Hinton and Wenzel, J Exp Psychol Learn Mem Cogn 25:1161-1176, 1999 and Anderson, J Exp Psychol [Hum Learn] 7:326-343, 1981. The two measures are linearly related through stimulus presentation lags from 0 to 594 s in the former experiment and for repeated learning of words in the latter. The Tagging/Retagging interpretation of short term memory is introduced to explain this linear relationship. At stimulus presentation the words are tagged. This tagging level drops slowly with time. When a probe word is reintroduced the tagging level has to increase for the word to be properly identified leading to a delay in response time. The tagging time is related to the meaningfulness of the words used-the more meaningful the word the longer the tagging time. After stimulus presentation the tagging level drops in a logarithmic fashion to 50% after 10 s and to 20% after 240 s. The incorrect recall and recognition times saturate in the Rubin et al. data set (they are not linear for large time lags), suggesting a limited time to search the short term memory structure: the search time for recall of unusual words is 1.7 s. For recognition of nonsense words the corresponding time is about 0.4 s, similar to the 0.243 s found in Cavanagh (1972).

  16. Disambiguating past events: accurate source memory for time and context depends on different retrieval processes

    OpenAIRE

    Persson, Bjorn Martin; Ainge, James Alexander; O'Connor, Akira Robert

    2016-01-01

    Participant payment was provided by the School of Psychology and Neuroscience ResPay scheme. Current animal models of episodic memory are usually based on demonstrating integrated memory for what happened, where it happened, and when an event took place. These models aim to capture the testable features of the definition of human episodic memory which stresses the temporal component of the memory as a unique piece of source information that allows us to disambiguate one memory from another...

  17. Remembering the Past and Thinking about the Future: Is It Really about Time?

    Science.gov (United States)

    Eacott, Madeline J.; Easton, Alexander

    2012-01-01

    In this paper we discuss some literature relating to episodic memory, future episodic thinking and mental time travel in humans and non-human animals. We discuss the concept of mental time travel and argue that the concept relies on subjective phenomena such as consciousness and on this basis is not useful when studying episodic memory and future…

  18. Entire Sound Representations Are Time-Compressed in Sensory Memory: Evidence from MMN.

    Science.gov (United States)

    Tamakoshi, Seiji; Minoura, Nanako; Katayama, Jun'ichi; Yagi, Akihiro

    2016-01-01

    In order to examine the encoding of partial silence included in a sound stimulus in neural representation, time flow of the sound representations was investigated using mismatch negativity (MMN), an ERP component that reflects neural representation in auditory sensory memory. Previous work suggested that time flow of auditory stimuli is compressed in neural representations. The stimuli used were a full-stimulus of 170 ms duration, an early-gap stimulus with silence for a 20-50 ms segment (i.e., an omitted segment), and a late-gap stimulus with an omitted segment of 110-140 ms. Peak MMNm latencies from oddball sequences of these stimuli, with a 500 ms SOA, did not reflect time point of the physical gap, suggesting that temporal information can be compressed in sensory memory. However, it was not clear whether the whole stimulus duration or only the omitted segment duration is compressed. Thus, stimuli were used in which the gap was replaced by a tone segment with a 1/4 sound pressure level (filled), as well as the gap stimuli. Combinations of full-stimuli and one of four gapped or filled stimuli (i.e., early gap, late gap, early filled, and late filled) were presented in an oddball sequence (85 vs. 15%). If compression occurs only for the gap duration, MMN latency for filled stimuli should show a different pattern from those for gap stimuli. MMN latencies for the filled conditions showed the same pattern as those for the gap conditions, indicating that the whole stimulus duration rather than only gap duration is compressed in sensory memory neural representation. These results suggest that temporal aspects of silence are encoded in the same manner as physical sound.

  19. Global asymptotic stability analysis of bidirectional associative memory neural networks with time delays.

    Science.gov (United States)

    Arik, Sabri

    2005-05-01

    This paper presents a sufficient condition for the existence, uniqueness and global asymptotic stability of the equilibrium point for bidirectional associative memory (BAM) neural networks with distributed time delays. The results impose constraint conditions on the network parameters of neural system independently of the delay parameter, and they are applicable to all continuous nonmonotonic neuron activation functions. It is shown that in some special cases of the results, the stability criteria can be easily checked. Some examples are also given to compare the results with the previous results derived in the literature.

  20. New results for global robust stability of bidirectional associative memory neural networks with multiple time delays

    International Nuclear Information System (INIS)

    Senan, Sibel; Arik, Sabri

    2009-01-01

    This paper presents some new sufficient conditions for the global robust asymptotic stability of the equilibrium point for bidirectional associative memory (BAM) neural networks with multiple time delays. The results we obtain impose constraint conditions on the network parameters of neural system independently of the delay parameter, and they are applicable to all bounded continuous non-monotonic neuron activation functions. We also give some numerical examples to demonstrate the applicability and effectiveness of our results, and compare the results with the previous robust stability results derived in the literature.

  1. A shared memory based interface of MARTe with EPICS for real-time applications

    International Nuclear Information System (INIS)

    Yun, Sangwon; Neto, André C.; Park, Mikyung; Lee, Sangil; Park, Kaprai

    2014-01-01

    Highlights: • We implemented a shared memory based interface of MARTe with EPICS. • We implemented an EPICS module supporting device and driver support. • We implemented an example EPICS IOC and CSS OPI for evaluation. - Abstract: The Multithreaded Application Real-Time executor (MARTe) is a multi-platform C++ middleware designed for the implementation of real-time control systems. It currently supports the Linux, Linux + RTAI, VxWorks, Solaris and MS Windows platforms. In the fusion community MARTe is being used at JET, COMPASS, ISTTOK, FTU and RFX in fusion [1]. The Experimental Physics and Industrial Control System (EPICS), a standard framework for the control systems in KSTAR and ITER, is a set of software tools and applications which provide a software infrastructure for use in building distributed control systems to operate devices. For a MARTe based application to cooperate with an EPICS based application, an interface layer between MARTe and EPICS is required. To solve this issue, a number of interfacing solutions have been proposed and some of them have been implemented. Nevertheless, a new approach is required to mitigate the functional limitations of existing solutions and to improve their performance for real-time applications. This paper describes the design and implementation of a shared memory based interface between MARTe and EPICS

  2. Two-time scale subordination in physical processes with long-term memory

    International Nuclear Information System (INIS)

    Stanislavsky, Aleksander; Weron, Karina

    2008-01-01

    We describe dynamical processes in continuous media with a long-term memory. Our consideration is based on a stochastic subordination idea and concerns two physical examples in detail. First we study a temporal evolution of the species concentration in a trapping reaction in which a diffusing reactant is surrounded by a sea of randomly moving traps. The analysis uses the random-variable formalism of anomalous diffusive processes. We find that the empirical trapping-reaction law, according to which the reactant concentration decreases in time as a product of an exponential and a stretched exponential function, can be explained by a two-time scale subordination of random processes. Another example is connected with a state equation for continuous media with memory. If the pressure and the density of a medium are subordinated in two different random processes, then the ordinary state equation becomes fractional with two-time scales. This allows one to arrive at the Bagley-Torvik type of state equation

  3. A shared memory based interface of MARTe with EPICS for real-time applications

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Sangwon, E-mail: yunsw@nfri.re.kr [National Fusion Research Institute (NFRI), Gwahangno 169-148, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of); Neto, André C. [Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, P-1049-001 Lisboa (Portugal); Park, Mikyung; Lee, Sangil; Park, Kaprai [National Fusion Research Institute (NFRI), Gwahangno 169-148, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of)

    2014-05-15

    Highlights: • We implemented a shared memory based interface of MARTe with EPICS. • We implemented an EPICS module supporting device and driver support. • We implemented an example EPICS IOC and CSS OPI for evaluation. - Abstract: The Multithreaded Application Real-Time executor (MARTe) is a multi-platform C++ middleware designed for the implementation of real-time control systems. It currently supports the Linux, Linux + RTAI, VxWorks, Solaris and MS Windows platforms. In the fusion community MARTe is being used at JET, COMPASS, ISTTOK, FTU and RFX in fusion [1]. The Experimental Physics and Industrial Control System (EPICS), a standard framework for the control systems in KSTAR and ITER, is a set of software tools and applications which provide a software infrastructure for use in building distributed control systems to operate devices. For a MARTe based application to cooperate with an EPICS based application, an interface layer between MARTe and EPICS is required. To solve this issue, a number of interfacing solutions have been proposed and some of them have been implemented. Nevertheless, a new approach is required to mitigate the functional limitations of existing solutions and to improve their performance for real-time applications. This paper describes the design and implementation of a shared memory based interface between MARTe and EPICS.

  4. Hydrodynamic perspective on memory in time-dependent density-functional theory

    International Nuclear Information System (INIS)

    Thiele, M.; Kuemmel, S.

    2009-01-01

    The adiabatic approximation of time-dependent density-functional theory is studied in the context of nonlinear excitations of two-electron singlet systems. We compare the exact time evolution of these systems to the adiabatically exact one obtained from time-dependent Kohn-Sham calculations relying on the exact ground-state exchange-correlation potential. Thus, we can show under which conditions the adiabatic approximation breaks down and memory effects become important. The hydrodynamic formulation of quantum mechanics allows us to interpret these results and relate them to dissipative effects in the Kohn-Sham system. We show how the breakdown of the adiabatic approximation can be inferred from the rate of change of the ground-state noninteracting kinetic energy.

  5. Robust state estimation for uncertain fuzzy bidirectional associative memory networks with time-varying delays

    Science.gov (United States)

    Vadivel, P.; Sakthivel, R.; Mathiyalagan, K.; Arunkumar, A.

    2013-09-01

    This paper addresses the issue of robust state estimation for a class of fuzzy bidirectional associative memory (BAM) neural networks with time-varying delays and parameter uncertainties. By constructing the Lyapunov-Krasovskii functional, which contains the triple-integral term and using the free-weighting matrix technique, a set of sufficient conditions are derived in terms of linear matrix inequalities (LMIs) to estimate the neuron states through available output measurements such that the dynamics of the estimation error system is robustly asymptotically stable. In particular, we consider a generalized activation function in which the traditional assumptions on the boundedness, monotony and differentiability of the activation functions are removed. More precisely, the design of the state estimator for such BAM neural networks can be obtained by solving some LMIs, which are dependent on the size of the time derivative of the time-varying delays. Finally, a numerical example with simulation result is given to illustrate the obtained theoretical results.

  6. Robust state estimation for uncertain fuzzy bidirectional associative memory networks with time-varying delays

    International Nuclear Information System (INIS)

    Vadivel, P; Sakthivel, R; Mathiyalagan, K; Arunkumar, A

    2013-01-01

    This paper addresses the issue of robust state estimation for a class of fuzzy bidirectional associative memory (BAM) neural networks with time-varying delays and parameter uncertainties. By constructing the Lyapunov–Krasovskii functional, which contains the triple-integral term and using the free-weighting matrix technique, a set of sufficient conditions are derived in terms of linear matrix inequalities (LMIs) to estimate the neuron states through available output measurements such that the dynamics of the estimation error system is robustly asymptotically stable. In particular, we consider a generalized activation function in which the traditional assumptions on the boundedness, monotony and differentiability of the activation functions are removed. More precisely, the design of the state estimator for such BAM neural networks can be obtained by solving some LMIs, which are dependent on the size of the time derivative of the time-varying delays. Finally, a numerical example with simulation result is given to illustrate the obtained theoretical results. (paper)

  7. Examining relationships between receiving mental health services in the Pennsylvania prison system and time served.

    Science.gov (United States)

    Metraux, Stephen

    2008-07-01

    This study examined a cohort of 7,046 men who were released from the Pennsylvania State prison system between 1999 and 2002 to Philadelphia County to assess the relationships between receipt of mental health services in prison and prison exit. Administrative data on prison stays for 7,046 men released from Pennsylvania prisons to Philadelphia locations were analyzed. Of the 7,046 men, 8.7% received ongoing or intensive mental health services and 25.9% received mental health services while incarcerated. Multivariate analyses indicate that use of mental health services was positively associated with increased odds of serving the full prison sentence (as opposed to receiving parole), although the relationship between mental health services received and length of prison episode was inconclusive. Dynamics related to prison release warrant further attention in efforts to reduce the prevalence of mental illness in prisons and to facilitate community reentry for persons so diagnosed.

  8. Time-place learning and memory persist in mice lacking functional Per1 and Per2 clock genes.

    Science.gov (United States)

    Mulder, C; Van Der Zee, E A; Hut, R A; Gerkema, M P

    2013-12-01

    With time-place learning, animals link a stimulus with the location and the time of day. This ability may optimize resource localization and predator avoidance in daily changing environments. Time-place learning is a suitable task to study the interaction of the circadian system and memory. Previously, we showed that time-place learning in mice depends on the circadian system and Cry1 and/or Cry2 clock genes. We questioned whether time-place learning is Cry specific or also depends on other core molecular clock genes. Here, we show that Per1/Per2 double mutant mice, despite their arrhythmic phenotype, acquire time-place learning similar to wild-type mice. As well as an established role in circadian rhythms, Per genes have also been implicated in the formation and storage of memory. We found no deficiencies in short-term spatial working memory in Per mutant mice compared to wild-type mice. Moreover, both Per mutant and wild-type mice showed similar long-term memory for contextual features of a paradigm (a mild foot shock), measured in trained mice after a 2-month nontesting interval. In contrast, time-place associations were lost in both wild-type and mutant mice after these 2 months, suggesting a lack of maintained long-term memory storage for this type of information. Taken together, Cry-dependent time-place learning does not require Per genes, and Per mutant mice showed no PER-specific short-term or long-term memory deficiencies. These results limit the functional role of Per clock genes in the circadian regulation of time-place learning and memory.

  9. Diminishing returns: the influence of experience and environment on time-memory extinction in honey bee foragers.

    Science.gov (United States)

    Moore, Darrell; Van Nest, Byron N; Seier, Edith

    2011-06-01

    Classical experiments demonstrated that honey bee foragers trained to collect food at virtually any time of day will return to that food source on subsequent days with a remarkable degree of temporal accuracy. This versatile time-memory, based on an endogenous circadian clock, presumably enables foragers to schedule their reconnaissance flights to best take advantage of the daily rhythms of nectar and pollen availability in different species of flowers. It is commonly believed that the time-memory rapidly extinguishes if not reinforced daily, thus enabling foragers to switch quickly from relatively poor sources to more productive ones. On the other hand, it is also commonly thought that extinction of the time-memory is slow enough to permit foragers to 'remember' the food source over a day or two of bad weather. What exactly is the time-course of time-memory extinction? In a series of field experiments, we determined that the level of food-anticipatory activity (FAA) directed at a food source is not rapidly extinguished and, furthermore, the time-course of extinction is dependent upon the amount of experience accumulated by the forager at that source. We also found that FAA is prolonged in response to inclement weather, indicating that time-memory extinction is not a simple decay function but is responsive to environmental changes. These results provide insights into the adaptability of FAA under natural conditions.

  10. 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: ...

  11. Electron spin echo studies of the internal motion of radicals in crystals: Phase memory vs correlation time

    International Nuclear Information System (INIS)

    Kispert, L.D.; Bowman, M.K.; Norris, J.R.; Brown, M.S.

    1982-01-01

    An electron spin echo (ESE) study of the internal motion of the CH 2 protons in irradiated zinc acetate dihydrate crystals shows that quantitative measurements of the motional correlation time can be obtained quite directly from pulsed measurements. In the slow motional limit, the motional correlation time is equal to the phase memory time determined by ESE. In the fast motional limit, the motional correlation time is proportional to the no motion spectral second moment divided by the ESE phase memory time. ESE offers a convenient method of studying motion, electron transfer, conductivity, etc. in a variety of systems too complicated for study by ordinary EPR. New systems for study by ESE include biological samples, organic polymers, liquid solutions of radicals with unresolved hyperfine, etc. When motion modulates large anisotropic hyperfine couplings, ESE measurements of the phase memory time are sensitive to modulation of pseudosecular hyperfine interactions

  12. Reliability over time of EEG-based mental workload evaluation during Air Traffic Management (ATM) tasks.

    Science.gov (United States)

    Arico, Pietro; Borghini, Gianluca; Di Flumeri, Gianluca; Colosimo, Alfredo; Graziani, Ilenia; Imbert, Jean-Paul; Granger, Geraud; Benhacene, Railene; Terenzi, Michela; Pozzi, Simone; Babiloni, Fabio

    2015-08-01

    Machine-learning approaches for mental workload (MW) estimation by using the user brain activity went through a rapid expansion in the last decades. In fact, these techniques allow now to measure the MW with a high time resolution (e.g. few seconds). Despite such advancements, one of the outstanding problems of these techniques regards their ability to maintain a high reliability over time (e.g. high accuracy of classification even across consecutive days) without performing any recalibration procedure. Such characteristic will be highly desirable in real world applications, in which human operators could use such approach without undergo a daily training of the device. In this work, we reported that if a simple classifier is calibrated by using a low number of brain spectral features, between those ones strictly related to the MW (i.e. Frontal and Occipital Theta and Parietal Alpha rhythms), those features will make the classifier performance stable over time. In other words, the discrimination accuracy achieved by the classifier will not degrade significantly across different days (i.e. until one week). The methodology has been tested on twelve Air Traffic Controls (ATCOs) trainees while performing different Air Traffic Management (ATM) scenarios under three different difficulty levels.

  13. Context and Time Matter: Effects of Emotion and Motivation on Episodic Memory Overtime.

    Science.gov (United States)

    Sun, Qing; Gu, Simeng; Yang, Jiongjiong

    2018-01-01

    Previous studies have shown that compared with neutral cues, stimuli with positive and negative/stressful contexts or reward and punishment cues are remembered better. However, it is unclear whether the enhanced effect differs in emotion or motivation dimensions and the passage of time. We addressed these issues by manipulating different contextual cues for neutral words at different time intervals. In experiment 1, subjects were asked to learn words with picture contexts in positive, negative/stressful, and neutral valences and were tested by old/new word recognition and contextual judgment 10 min, 1 day, and 1 week later. In experiment 2, the reward and punishment motivations were manipulated by monetary cues during learning. Word recognition and contextual judgment were assessed 10 min, 1 day, 1 week, and 1 month after the study. Compared with negative and punishment conditions, the words in positive and reward contexts were recognized better at shorter intervals, which was associated with recollection process. In contrast, the words in negative and punishment contexts were recognized better at longer intervals, which was mainly associated with familiarity process. These results clarified how different dimensions of emotional and motivational contexts influence memory at short and long intervals and highlighted the role of contextual features in memory formation and consolidation.

  14. Time and spatial concentration profile inside a membrane by means of a memory formalism

    Science.gov (United States)

    Caputo, Michele; Cametti, Cesare; Ruggero, Vittorio

    2008-03-01

    In this note, the profile concentration of diffusing particles inside a membrane has been calculated on the basis of the Fick diffusion equation modified by introducing a memory formalism. In highly heterogeneous systems, such as biological membranes, the intrinsic structural complexity of the medium restricts the applicability of continuum diffusion models and suggests that diffusion parameters could depend at a certain time or position on what happens at preceding times (diffusion with memory). Here, we deal with two particular cases, the diffusion of glucose across an erythrocyte membrane, when the concentration at both sides of the membrane are assigned, and the permeation transport of small molecular weight solute through an artificial hydrogel polymeric membrane. However, the present procedure can be easily extended to more general conditions. The knowledge of the concentration profile within a membranous structure, which is usually not easily experimentally accessible, completes the description of the rather complex phenomenon of the transport across a highly structured confined medium and can also lead to an improvement in controlled drug-delivery systems.

  15. Context and Time Matter: Effects of Emotion and Motivation on Episodic Memory Overtime

    Science.gov (United States)

    Sun, Qing; Gu, Simeng

    2018-01-01

    Previous studies have shown that compared with neutral cues, stimuli with positive and negative/stressful contexts or reward and punishment cues are remembered better. However, it is unclear whether the enhanced effect differs in emotion or motivation dimensions and the passage of time. We addressed these issues by manipulating different contextual cues for neutral words at different time intervals. In experiment 1, subjects were asked to learn words with picture contexts in positive, negative/stressful, and neutral valences and were tested by old/new word recognition and contextual judgment 10 min, 1 day, and 1 week later. In experiment 2, the reward and punishment motivations were manipulated by monetary cues during learning. Word recognition and contextual judgment were assessed 10 min, 1 day, 1 week, and 1 month after the study. Compared with negative and punishment conditions, the words in positive and reward contexts were recognized better at shorter intervals, which was associated with recollection process. In contrast, the words in negative and punishment contexts were recognized better at longer intervals, which was mainly associated with familiarity process. These results clarified how different dimensions of emotional and motivational contexts influence memory at short and long intervals and highlighted the role of contextual features in memory formation and consolidation. PMID:29849564

  16. Context and Time Matter: Effects of Emotion and Motivation on Episodic Memory Overtime

    Directory of Open Access Journals (Sweden)

    Qing Sun

    2018-01-01

    Full Text Available Previous studies have shown that compared with neutral cues, stimuli with positive and negative/stressful contexts or reward and punishment cues are remembered better. However, it is unclear whether the enhanced effect differs in emotion or motivation dimensions and the passage of time. We addressed these issues by manipulating different contextual cues for neutral words at different time intervals. In experiment 1, subjects were asked to learn words with picture contexts in positive, negative/stressful, and neutral valences and were tested by old/new word recognition and contextual judgment 10 min, 1 day, and 1 week later. In experiment 2, the reward and punishment motivations were manipulated by monetary cues during learning. Word recognition and contextual judgment were assessed 10 min, 1 day, 1 week, and 1 month after the study. Compared with negative and punishment conditions, the words in positive and reward contexts were recognized better at shorter intervals, which was associated with recollection process. In contrast, the words in negative and punishment contexts were recognized better at longer intervals, which was mainly associated with familiarity process. These results clarified how different dimensions of emotional and motivational contexts influence memory at short and long intervals and highlighted the role of contextual features in memory formation and consolidation.

  17. Manipulating motor performance and memory through real-time fMRI neurofeedback.

    Science.gov (United States)

    Scharnowski, Frank; Veit, Ralf; Zopf, Regine; Studer, Petra; Bock, Simon; Diedrichsen, Jörn; Goebel, Rainer; Mathiak, Klaus; Birbaumer, Niels; Weiskopf, Nikolaus

    2015-05-01

    Task performance depends on ongoing brain activity which can be influenced by attention, arousal, or motivation. However, such modulating factors of cognitive efficiency are unspecific, can be difficult to control, and are not suitable to facilitate neural processing in a regionally specific manner. Here, we non-pharmacologically manipulated regionally specific brain activity using technically sophisticated real-time fMRI neurofeedback. This was accomplished by training participants to simultaneously control ongoing brain activity in circumscribed motor and memory-related brain areas, namely the supplementary motor area and the parahippocampal cortex. We found that learned voluntary control over these functionally distinct brain areas caused functionally specific behavioral effects, i.e. shortening of motor reaction times and specific interference with memory encoding. The neurofeedback approach goes beyond improving cognitive efficiency by unspecific psychological factors such as attention, arousal, or motivation. It allows for directly manipulating sustained activity of task-relevant brain regions in order to yield specific behavioral or cognitive effects. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Timing and gender determine if acute pain impairs working memory performance.

    Science.gov (United States)

    Hood, Anna; Pulvers, Kim; Spady, Thomas J

    2013-11-01

    The effects of pain on memory are complex, and little is known about the vulnerability of working memory (WM) performance when individuals complete a WM test while concurrently experiencing pain. Here, we subjected 78 healthy nonsmoking participants to either acute pain or a control condition while we administered a WM test. In this context, we also tested WM 20 minutes after pain in order to determine if timing of pain affected WM performance, and assessed objective and subjective measures of pain. We hypothesized that pain would impair WM performance during pain. Further, women's WM performance would be impaired more than men. Importantly, there was an interaction between gender and condition, with women exposed to pain experiencing impairments during but not after the cold pressor task. Our data imply that timing and gender are critically important in whether acute pain is costly to WM performance. Our findings have interesting clinical, professional, and educational implications, and understanding the influence of pain could help to improve the interpretation of WM tests in these diverse settings. Results of this study support the growing body of work that attests to the detrimental effect of pain on WM performance. Further, this study provides new evidence that concurrently experiencing cold pressor pain impairs WM in regularly menstruating women and women taking a contraceptive. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  19. A method for real-time memory efficient implementation of blob detection in large images

    Directory of Open Access Journals (Sweden)

    Petrović Vladimir L.

    2017-01-01

    Full Text Available In this paper we propose a method for real-time blob detection in large images with low memory cost. The method is suitable for implementation on the specialized parallel hardware such as multi-core platforms, FPGA and ASIC. It uses parallelism to speed-up the blob detection. The input image is divided into blocks of equal sizes to which the maximally stable extremal regions (MSER blob detector is applied in parallel. We propose the usage of multiresolution analysis for detection of large blobs which are not detected by processing the small blocks. This method can find its place in many applications such as medical imaging, text recognition, as well as video surveillance or wide area motion imagery (WAMI. We explored the possibilities of usage of detected blobs in the feature-based image alignment as well. When large images are processed, our approach is 10 to over 20 times more memory efficient than the state of the art hardware implementation of the MSER.

  20. Manipulating motor performance and memory through real-time fMRI neurofeedback

    Science.gov (United States)

    Scharnowski, Frank; Veit, Ralf; Zopf, Regine; Studer, Petra; Bock, Simon; Diedrichsen, Jörn; Goebel, Rainer; Mathiak, Klaus; Birbaumer, Niels; Weiskopf, Nikolaus

    2015-01-01

    Task performance depends on ongoing brain activity which can be influenced by attention, arousal, or motivation. However, such modulating factors of cognitive efficiency are unspecific, can be difficult to control, and are not suitable to facilitate neural processing in a regionally specific manner. Here, we non-pharmacologically manipulated regionally specific brain activity using technically sophisticated real-time fMRI neurofeedback. This was accomplished by training participants to simultaneously control ongoing brain activity in circumscribed motor and memory-related brain areas, namely the supplementary motor area and the parahippocampal cortex. We found that learned voluntary control over these functionally distinct brain areas caused functionally specific behavioral effects, i.e. shortening of motor reaction times and specific interference with memory encoding. The neurofeedback approach goes beyond improving cognitive efficiency by unspecific psychological factors such as attention, arousal, or motivation. It allows for directly manipulating sustained activity of task-relevant brain regions in order to yield specific behavioral or cognitive effects. PMID:25796342

  1. Estimating Whether Replacing Time in Active Outdoor Play and Sedentary Video Games With Active Video Games Influences Youth's Mental Health.

    Science.gov (United States)

    Janssen, Ian

    2016-11-01

    The primary objective was to use isotemporal substitution models to estimate whether replacing time spent in sedentary video games (SVGs) and active outdoor play (AOP) with active video games (AVGs) would be associated with changes in youth's mental health. A representative sample of 20,122 Canadian youth in Grades 6-10 was studied. The exposure variables were average hours/day spent playing AVGs, SVGs, and AOP. The outcomes consisted of a negative and internalizing mental health indicator (emotional problems), a positive and internalizing mental health indicator (life satisfaction), and a positive and externalizing mental health indicator (prosocial behavior). Isotemporal substitution models estimated the extent to which replacing time spent in SVGs and AOP with an equivalent amount of time in AVGs had on the mental health indicators. Replacing 1 hour/day of SVGs with 1 hour/day of AVGs was associated with a 6% (95% confidence interval: 3%-9%) reduced probability of high emotional problems, a 4% (2%-7%) increased probability of high life satisfaction, and a 13% (9%-16%) increased probability of high prosocial behavior. Replacing 1 hour/day of AOP with 1 hour/day of AVGs was associated with a 7% (3%-11%) increased probability of high emotional problems, a 3% (1%-5%) reduced probability of high life satisfaction, and a 6% (2%-9%) reduced probability of high prosocial behavior. Replacing SVGs with AVGs was associated with more preferable mental health indicators. Conversely, replacing AOP with AVGs was associated with more deleterious mental health indicators. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  2. Electrophysiological correlates of strategic monitoring in event-based and time-based prospective memory.

    Directory of Open Access Journals (Sweden)

    Giorgia Cona

    Full Text Available Prospective memory (PM is the ability to remember to accomplish an action when a particular event occurs (i.e., event-based PM, or at a specific time (i.e., time-based PM while performing an ongoing activity. Strategic Monitoring is one of the basic cognitive functions supporting PM tasks, and involves two mechanisms: a retrieval mode, which consists of maintaining active the intention in memory; and target checking, engaged for verifying the presence of the PM cue in the environment. The present study is aimed at providing the first evidence of event-related potentials (ERPs associated with time-based PM, and at examining differences and commonalities in the ERPs related to Strategic Monitoring mechanisms between event- and time-based PM tasks.The addition of an event-based or a time-based PM task to an ongoing activity led to a similar sustained positive modulation of the ERPs in the ongoing trials, mainly expressed over prefrontal and frontal regions. This modulation might index the retrieval mode mechanism, similarly engaged in the two PM tasks. On the other hand, two further ERP modulations were shown specifically in an event-based PM task. An increased positivity was shown at 400-600 ms post-stimulus over occipital and parietal regions, and might be related to target checking. Moreover, an early modulation at 130-180 ms post-stimulus seems to reflect the recruitment of attentional resources for being ready to respond to the event-based PM cue. This latter modulation suggests the existence of a third mechanism specific for the event-based PM; that is, the "readiness mode".

  3. 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

  4. Time-dependent effects of cortisol on the contextualization of emotional memories

    NARCIS (Netherlands)

    van Ast, V.A.; Cornelisse, S.; Meeter, M.; Joëls, M.; Kindt, M.

    2013-01-01

    Background: The inability to store fearful memories into their original encoding context is considered to be an important vulnerability factor for the development of anxiety disorders like posttraumatic stress disorder. Altered memory contextualization most likely involves effects of the stress

  5. Role of aging and hippocampus in Time-Place Learning: link to episodic-like memory?

    Directory of Open Access Journals (Sweden)

    Cornelis Kees Mulder

    2016-01-01

    Full Text Available Introduction: with time-place learning (TPL, animals link an event with the spatial location and the time of day. The what-where-when TPL components make the task putatively episodic-like in nature. Animals use an internal sense of time to master TPL, which is circadian system based. Finding indications for a role of the hippocampus and (early aging-sensitivity in TPL would strengthen the episodic-like memory nature of the paradigm. Methods: previously, we used C57Bl/6 mice for our TPL research. Here, we used CD1 mice which are less hippocampal-driven and age faster compared to C57Bl/6 mice. To demonstrate the low degree of hippocampal-driven performance in CD1 mice, a cross maze was used. The spontaneous alternation test was used to score spatial working memory in CD1 mice at four different age categories (young (3-6 months, middle-aged (7-11 months, aged (12-18 months and old (>19 months. TPL performance of middle-aged and aged CD1 mice was tested in a setup with either two or three time points per day (2-arm or 3-arm TPL task. Immunostainings was applied on brains of young and middle-aged C57Bl/6 mice that had successfully mastered the 3-arm TPL task. Results: in contrast to C57Bl/6 mice, middle-aged and aged CD1 mice were less hippocampus-driven and failed to master the 3-arm TPL task. They could, however, master the 2-arm TPL task primarily via an ordinal (non-circadian timing system. c-Fos, CRY2, vasopressin (AVP, and pCREB were investigated. We found no differences at the level of the suprachiasmatic nucleus (SCN; circadian master clock, whereas CRY2 expression was increased in the hippocampal dentate gyrus. The most pronounced difference between TPL trained and control mice was found in c-Fos expression in the paraventricular thalamic nucleus, a circadian system relay station. Conclusions: These results further indicate a key role of CRY proteins in TPL and confirm the limited role of the SCN in TPL. Based on the poor TPL performance of

  6. A One-Pass Real-Time Decoder Using Memory-Efficient State Network

    Science.gov (United States)

    Shao, Jian; Li, Ta; Zhang, Qingqing; Zhao, Qingwei; Yan, Yonghong

    This paper presents our developed decoder which adopts the idea of statically optimizing part of the knowledge sources while handling the others dynamically. The lexicon, phonetic contexts and acoustic model are statically integrated to form a memory-efficient state network, while the language model (LM) is dynamically incorporated on the fly by means of extended tokens. The novelties of our approach for constructing the state network are (1) introducing two layers of dummy nodes to cluster the cross-word (CW) context dependent fan-in and fan-out triphones, (2) introducing a so-called “WI layer” to store the word identities and putting the nodes of this layer in the non-shared mid-part of the network, (3) optimizing the network at state level by a sufficient forward and backward node-merge process. The state network is organized as a multi-layer structure for distinct token propagation at each layer. By exploiting the characteristics of the state network, several techniques including LM look-ahead, LM cache and beam pruning are specially designed for search efficiency. Especially in beam pruning, a layer-dependent pruning method is proposed to further reduce the search space. The layer-dependent pruning takes account of the neck-like characteristics of WI layer and the reduced variety of word endings, which enables tighter beam without introducing much search errors. In addition, other techniques including LM compression, lattice-based bookkeeping and lattice garbage collection are also employed to reduce the memory requirements. Experiments are carried out on a Mandarin spontaneous speech recognition task where the decoder involves a trigram LM and CW triphone models. A comparison with HDecode of HTK toolkits shows that, within 1% performance deviation, our decoder can run 5 times faster with half of the memory footprint.

  7. Effects of Network Structure, Competition and Memory Time on Social Spreading Phenomena

    Science.gov (United States)

    Gleeson, James P.; O'Sullivan, Kevin P.; Baños, Raquel A.; Moreno, Yamir

    2016-04-01

    Online social media has greatly affected the way in which we communicate with each other. However, little is known about what fundamental mechanisms drive dynamical information flow in online social systems. Here, we introduce a generative model for online sharing behavior that is analytically tractable and that can reproduce several characteristics of empirical micro-blogging data on hashtag usage, such as (time-dependent) heavy-tailed distributions of meme popularity. The presented framework constitutes a null model for social spreading phenomena that, in contrast to purely empirical studies or simulation-based models, clearly distinguishes the roles of two distinct factors affecting meme popularity: the memory time of users and the connectivity structure of the social network.

  8. Effects of Network Structure, Competition and Memory Time on Social Spreading Phenomena

    Directory of Open Access Journals (Sweden)

    James P. Gleeson

    2016-05-01

    Full Text Available Online social media has greatly affected the way in which we communicate with each other. However, little is known about what fundamental mechanisms drive dynamical information flow in online social systems. Here, we introduce a generative model for online sharing behavior that is analytically tractable and that can reproduce several characteristics of empirical micro-blogging data on hashtag usage, such as (time-dependent heavy-tailed distributions of meme popularity. The presented framework constitutes a null model for social spreading phenomena that, in contrast to purely empirical studies or simulation-based models, clearly distinguishes the roles of two distinct factors affecting meme popularity: the memory time of users and the connectivity structure of the social network.

  9. Nonvolatile organic write-once-read-many-times memory devices based on hexadecafluoro-copper-phthalocyanine

    Science.gov (United States)

    Wang, Lidan; Su, Zisheng; Wang, Cheng

    2012-05-01

    Nonvolatile organic write-once-read-many-times memory device was demonstrated based on hexadecafluoro-copper-phthalocyanine (F16CuPc) single layer sandwiched between indium tin oxide (ITO) anode and Al cathode. The as fabricated device remains in ON state and it can be tuned to OFF state by applying a reverse bias. The ON/OFF current ratio of the device can reach up to 2.3 × 103. Simultaneously, the device shows long-term storage stability and long retention time in air. The ON/OFF transition is attributed to the formation and destruction of the interfacial dipole layer in the ITO/F16CuPc interface, and such a mechanism is different from previously reported ones.

  10. Robust stability of interval bidirectional associative memory neural network with time delays.

    Science.gov (United States)

    Liao, Xiaofeng; Wong, Kwok-wo

    2004-04-01

    In this paper, the conventional bidirectional associative memory (BAM) neural network with signal transmission delay is intervalized in order to study the bounded effect of deviations in network parameters and external perturbations. The resultant model is referred to as a novel interval dynamic BAM (IDBAM) model. By combining a number of different Lyapunov functionals with the Razumikhin technique, some sufficient conditions for the existence of unique equilibrium and robust stability are derived. These results are fairly general and can be verified easily. To go further, we extend our investigation to the time-varying delay case. Some robust stability criteria for BAM with perturbations of time-varying delays are derived. Besides, our approach for the analysis allows us to consider several different types of activation functions, including piecewise linear sigmoids with bounded activations as well as the usual C1-smooth sigmoids. We believe that the results obtained have leading significance in the design and application of BAM neural networks.

  11. Robust stability for stochastic bidirectional associative memory neural networks with time delays

    Science.gov (United States)

    Shu, H. S.; Lv, Z. W.; Wei, G. L.

    2008-02-01

    In this paper, the asymptotic stability is considered for a class of uncertain stochastic bidirectional associative memory neural networks with time delays and parameter uncertainties. The delays are time-invariant and the uncertainties are norm-bounded that enter into all network parameters. The aim of this paper is to establish easily verifiable conditions under which the delayed neural network is robustly asymptotically stable in the mean square for all admissible parameter uncertainties. By employing a Lyapunov-Krasovskii functional and conducting the stochastic analysis, a linear matrix inequality matrix inequality (LMI) approach is developed to derive the stability criteria. The proposed criteria can be easily checked by the Matlab LMI toolbox. A numerical example is given to demonstrate the usefulness of the proposed criteria.

  12. Stability in Cohen Grossberg-type bidirectional associative memory neural networks with time-varying delays

    Science.gov (United States)

    Cao, Jinde; Song, Qiankun

    2006-07-01

    In this paper, the exponential stability problem is investigated for a class of Cohen-Grossberg-type bidirectional associative memory neural networks with time-varying delays. By using the analysis method, inequality technique and the properties of an M-matrix, several novel sufficient conditions ensuring the existence, uniqueness and global exponential stability of the equilibrium point are derived. Moreover, the exponential convergence rate is estimated. The obtained results are less restrictive than those given in the earlier literature, and the boundedness and differentiability of the activation functions and differentiability of the time-varying delays are removed. Two examples with their simulations are given to show the effectiveness of the obtained results.

  13. Memory State Feedback RMPC for Multiple Time-Delayed Uncertain Linear Systems with Input Constraints

    Directory of Open Access Journals (Sweden)

    Wei-Wei Qin

    2014-01-01

    Full Text Available This paper focuses on the problem of asymptotic stabilization for a class of discrete-time multiple time-delayed uncertain linear systems with input constraints. Then, based on the predictive control principle of receding horizon optimization, a delayed state dependent quadratic function is considered for incorporating MPC problem formulation. By developing a memory state feedback controller, the information of the delayed plant states can be taken into full consideration. The MPC problem is formulated to minimize the upper bound of infinite horizon cost that satisfies the sufficient conditions. Then, based on the Lyapunov-Krasovskii function, a delay-dependent sufficient condition in terms of linear matrix inequality (LMI can be derived to design a robust MPC algorithm. Finally, the digital simulation results prove availability of the proposed method.

  14. Child and adolescent mental health care in Dutch general practice: time trend analyses.

    NARCIS (Netherlands)

    Zwaanswijk, M.; Dijk, C.E. van; Verheij, R.A.

    2011-01-01

    Background: Because most children and adolescents visit their general practitioner (GP) regularly, general practice is a useful setting in which child and adolescent mental health problems can be identified, treated or referred to specialised care. Measures to strengthen Dutch primary mental health

  15. VA Mental Health: Clearer Guidance on Access Policies and Wait-Time Data Needed

    Science.gov (United States)

    2015-10-01

    Abuse and Mental Health Services Administration, the nation faces a current shortage in the mental health and addiction services workforce, and that...order. Call for additional information. Connect with GAO on Facebook , Flickr, Twitter, and YouTube. Subscribe to our RSS Feeds or E-mail Updates

  16. The Effect of Part-time Sick Leave for Employees with Mental Disorders

    DEFF Research Database (Denmark)

    Holm, Anders; Høgelund, Jan; Eplov, Lene Falgaard

    2012-01-01

    . Without this control, PTSL significantly reduces the duration until returning to regular working hours. When we control for unobserved characteristics, this effect decreases, and for employees with mental disorders the effect vanishes entirely. DISCUSSION AND LIMITATIONS: The lack of an effect of PTSL...... instrument for reducing sick leave durations for employees with musculoskeletal disorders and for employees on sick leave in general. This is the first published article to document how PTSL affects sick leave durations for employees with mental disorders. AIM: The aim is to estimate the effect of PTSL...... on the duration until returning to regular working hours for employees with mental disorders. We compare this effect to that of PTSL for employees with non-mental disorders ('other disorders'). METHODS: We use combined survey and register data about 226 employees on long-term sick leave with mental disorders...

  17. Does part-time sick leave help individuals with mental disorders recover lost work capacity?

    Science.gov (United States)

    Andrén, Daniela

    2014-06-01

    This paper aims to answer the question whether combining sick leave with some hours of work can help employees diagnosed with a mental disorder (MD) increase their probability of returning to work. Given the available data, this paper analyzes the impact of part-time sick leave (PTSL) on the probability of fully recovering lost work capacity for employees diagnosed with an MD. The effects of PTSL on the probability of fully recovering lost work capacity are estimated by a discrete choice one-factor model using data on a nationally representative sample extracted from the register of the National Agency of Social Insurance in Sweden and supplemented with information from questionnaires. All individuals in the sample were 20-64 years old and started a sickness spell of at least 15 days between 1 and 16 February 2001. We selected all employed individuals diagnosed with an MD, with a final sample of 629 individuals. The results show that PTSL is associated with a low likelihood of full recovery, yet the timing of the assignment is important. PTSL's effect is relatively low (0.015) when it is assigned in the beginning of the spell but relatively high (0.387), and statistically significant, when assigned after 60 days of full-time sick leave (FTSL). This suggests efficiency improvements from assigning employees with an MD diagnosis, when possible, to PTSL. The employment gains will be enhanced if employees with an MD diagnosis are encouraged to return to work part-time after 60 days or more of FTSL.

  18. Acoustic Masking Disrupts Time-Dependent Mechanisms of Memory Encoding in Word-List Recall

    Science.gov (United States)

    Cousins, Katheryn A.Q.; Dar, Jonathan; Wingfield, Arthur; Miller, Paul

    2013-01-01

    Recall of recently heard words is affected by the clarity of presentation: even if all words are presented with sufficient clarity for successful recognition, those that are more difficult to hear are less likely to be recalled. Such a result demonstrates that memory processing depends on more than whether a word is simply “recognized” versus “not-recognized”. More surprising is that when a single item in a list of spoken words is acoustically masked, prior words that were heard with full clarity are also less likely to be recalled. To account for such a phenomenon, we developed the Linking by Active Maintenance Model (LAMM). This computational model of perception and encoding predicts that these effects are time dependent. Here we challenge our model by investigating whether and how the impact of acoustic masking on memory depends on presentation rate. We find that a slower presentation rate causes a more disruptive impact of stimulus degradation on prior, clearly heard words than does a fast rate. These results are unexpected according to prior theories of effortful listening, but we demonstrate that they can be accounted for by LAMM. PMID:24838269

  19. Factors associated with suicide among adolescents and young adults not in mental health treatment at time of death.

    Science.gov (United States)

    McLone, Suzanne G; Kouvelis, Antigone; Mason, Maryann; Sheehan, Karen

    2016-10-01

    Suicide is the third-leading cause of death among Illinois residents aged 15 to 24 years. The Illinois Violent Death Reporting System (IVDRS) was developed to help prevent these deaths by providing timely, complete data. Understanding the circumstances surrounding suicide for those aged 15 to 24 years who are not receiving mental health treatment can help others: (1) recognize signs of potential crisis and (2) connect them to mental health treatment. The IVDRS data were collected from five Illinois counties-Cook, DuPage, Kane, McHenry, and Peoria-from 2005 to 2010. All cases with the manner suicide, aged 15 to 24 years, were extracted for analysis. Data were described using frequencies and percentages, and statistical differences between groups were determined using χ analysis. There were a total of 386 suicides in those aged 15 to 24 years in IVDRS from 2005 to 2010. Most 15- to 19-year-olds (67%) and 20- to 24-year-olds (78%) were not receiving mental health treatment at the time of death. Among those not receiving mental health treatment, 22% and 13% of those aged 15 to 19 and 20 to 24 years, respectively, had disclosed their intent to commit suicide to another. One third were identified as being depressed or in a depressed mood (not necessarily a clinical diagnosis) in both age groups. One quarter in both age groups experienced a crisis (current, acute precipitating, or forthcoming event) within 2 weeks of their suicides. The majority of adolescents and young adults were not in mental health treatment at the time death. Among those not in mental health treatment at the time of death, the 15- to 19-year-olds were more likely to share their suicidal intentions than the 20- to 24-year-olds. Epidemiological study, level IV.

  20. Leisure activities are linked to mental health benefits by providing time structure: comparing employed, unemployed and homemakers.

    Science.gov (United States)

    Goodman, William K; Geiger, Ashley M; Wolf, Jutta M

    2017-01-01

    Unemployment has consistently been linked to negative mental health outcomes, emphasising the need to characterise the underlying mechanisms. The current study aimed at testing whether compared with other employment groups, fewer leisure activities observed in unemployment may contribute to elevated risk for negative mental health via loss of time structure. Depressive symptoms (Center for Epidemiologic Studies Depression), leisure activities (exercise, self-focused, social), and time structure (Time Structure Questionnaire (TSQ)) were assessed cross-sectionally in 406 participants (unemployed=155, employed=140, homemakers=111) recruited through Amazon Mechanical Turk. Controlling for gender and age, structural equation modelling revealed time structure partially (employed, homemakers) and fully (unemployed) mediated the relationship between leisure activities and depressive symptoms. With the exception of differential effects for structured routines, all other TSQ factors (sense of purpose, present orientation, effective organisation and persistence) contributed significantly to all models. These findings support the idea that especially for the unemployed, leisure activities impose their mental health benefits through increasing individuals' perception of spending their time effectively. Social leisure activities that provide a sense of daily structure may thereby be a particularly promising low-cost intervention to improve mental health in this population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  1. History of Mental Health Services South Mrica

    African Journals Online (AJOL)

    1974-11-02

    Nov 2, 1974 ... A short while after his birth, the Hullah family moved into the superintendent's ... tence for a long time at that stage, because the Commis- sioner for Mental ..... the Red Cross War Memorial Children's Hospital. It has expanded ...

  2. An Examination of Mental Time Travel and Its Role in the Development of Foresightful/Prudential Intellect

    Science.gov (United States)

    Parlar, Ugur

    Mental time travel (MTT) has always been a crucial component of human cognition, but has not always been identified or supported in schooling. Recent advances in psychological science consider MTT to be responsible for future-oriented thought and action, particularly, the formation of foresight. Therefore, an innovative research trajectory for education is to enabling students to harness their MTT abilities and support the development of what could be called foresightful/prudential intellect. By enhancing the flexibility and the reach of MTT ability, education can enable students to develop foresightful/prudential reasoning skills in science, technology, engineering, and mathematics (STEM) domains, including the ability to carry out collaborative MTT. Some of these skills are ecological problem identification and solution, environmental decision-making, root-cause analysis, spatial reasoning, and evolutionary thinking. This thesis first examines the evolution and development of MTT by combining studies in cognitive-developmental science, biological anthropology, and evolutionary neuroscience. A secondary examination reveals that although foresightful/prudential intellect is more closely associated with cognitive self-governance, clear benchmarks for assessing and supporting this intellect via MTT tasks need to be identified. A developmental study that used a dynamic system problem illustrates the ways foresightful/prudential reasoning manifests itself. Quantitative and qualitative differences are found in school-aged children's and undergraduate students' episodic memory syntheses when they were asked how to prevent the problem from reoccurring. The results of this study suggest that foresightful/prudential reasoning skills in environmental topics could be extrapolated to entire classrooms by designing MTT-based learning tools or tasks. Two prominent techniques are identified to show what these tools, tasks, or techniques could involve and how they could be

  3. A New Local Bipolar Autoassociative Memory Based on External Inputs of Discrete Recurrent Neural Networks With Time Delay.

    Science.gov (United States)

    Zhou, Caigen; Zeng, Xiaoqin; Luo, Chaomin; Zhang, Huaguang

    In this paper, local bipolar auto-associative memories are presented based on discrete recurrent neural networks with a class of gain type activation function. The weight parameters of neural networks are acquired by a set of inequalities without the learning procedure. The global exponential stability criteria are established to ensure the accuracy of the restored patterns by considering time delays and external inputs. The proposed methodology is capable of effectively overcoming spurious memory patterns and achieving memory capacity. The effectiveness, robustness, and fault-tolerant capability are validated by simulated experiments.In this paper, local bipolar auto-associative memories are presented based on discrete recurrent neural networks with a class of gain type activation function. The weight parameters of neural networks are acquired by a set of inequalities without the learning procedure. The global exponential stability criteria are established to ensure the accuracy of the restored patterns by considering time delays and external inputs. The proposed methodology is capable of effectively overcoming spurious memory patterns and achieving memory capacity. The effectiveness, robustness, and fault-tolerant capability are validated by simulated experiments.

  4. Retrieving autobiographical memories: How different retrieval strategies associated with different cues explain reaction time differences.

    Science.gov (United States)

    Uzer, Tugba

    2016-02-01

    Previous research has shown that memories cued by concrete concepts, such as objects, are retrieved faster than those cued by more abstract concepts, such as emotions. This effect has been explained by the fact that more memories are directly retrieved from object versus emotion cues. In the present study, we tested whether RT differences between memories cued by emotion versus object terms occur not only because object cues elicit direct retrieval of more memories (Uzer, Lee, & Brown, 2012), but also because of differences in memory generation in response to emotions versus objects. One hundred university students retrieved memories in response to basic-level (e.g. orange), superordinate-level (e.g. plant), and emotion (e.g. surprised) cues. Retrieval speed was measured and participants reported whether memories were directly retrieved or generated on each trial. Results showed that memories were retrieved faster in response to basic-level versus superordinate-level and emotion cues because a) basic-level cues elicited more directly retrieved memories, and b) generating memories was more difficult when cues were abstract versus concrete. These results suggest that generative retrieval is a cue generation process in which additional cues that provide contextual information including the target event are produced. Memories are retrieved more slowly in response to emotion cues in part because emotion labels are less effective cues of appropriate contextual information. This particular finding is inconsistent with the idea that emotion is a primary organizational unit for autobiographical memories. In contrast, the difficulty of emotional memory generation implies that emotions represent low-level event information in the organization of autobiographical memory. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Is time spent playing video games associated with mental health, cognitive and social skills in young children?

    NARCIS (Netherlands)

    Kovess-Masfety, V.; Keyes, K.M.; Hamilton, A.; Hanson, G.; Bitfoi, A.; Golitz, D.; Koç, C.; Kuijpers, R.C.W.M.; Lesinskiene, S.; Mihova, Z.; Otten, R.; Fermanian, C.; Pez, O.

    2016-01-01

    Video games are one of the favourite leisure activities of children; the influence on child health is usually perceived to be negative. The present study assessed the association between the amount of time spent playing video games and children mental health as well as cognitive and social skills.

  6. Work time control and mental health of workers working long hours: the role of gender and age.

    Science.gov (United States)

    Zołnierczyk-Zreda, Dorota; Bedyńska, Sylwia; Warszewska-Makuch, Magdalena

    2012-01-01

    The aim of this study was to examine the relationship between work time control and mental health in workers working long hours. The study also attempted to show how that relationship depended on age and gender. Three hundred and six white-collar workers doing clerical work for over 8 h daily were diagnosed on work time control and mental health with the 28-item General Health Questionnaire. The results of an analysis of variance (ANOVA) showed that participants working long hours but having high control over their work time had a significantly higher level of their mental health with regard to somatic complaints and anxiety and marginally higher with regard to social dysfunction than workers with low control over their work time. Male and female workers reported different problems with their mental health depending on what age (stage of life) they were at. It is hypothesized that the work-family conflict, inability to fulfil social commitments and poor working conditions can influence those effects.

  7. 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...

  8. Load-dependent brain activation assessed by time-domain functional near-infrared spectroscopy during a working memory task with graded levels of difficulty

    Science.gov (United States)

    Molteni, Erika; Contini, Davide; Caffini, Matteo; Baselli, Giuseppe; Spinelli, Lorenzo; Cubeddu, Rinaldo; Cerutti, Sergio; Bianchi, Anna Maria; Torricelli, Alessandro

    2012-05-01

    We evaluated frontal brain activation during a mixed attentional/working memory task with graded levels of difficulty in a group of 19 healthy subjects, by means of time-domain functional near-infrared spectroscopy (fNIRS). Brain activation was assessed, and load-related oxy- and deoxy-hemoglobin changes were studied. Generalized linear model (GLM) was applied to the data to explore the metabolic processes occurring during the mental effort and, possibly, their involvement in short-term memorization. GLM was applied to the data twice: for modeling the task as a whole and for specifically investigating brain activation at each cognitive load. This twofold employment of GLM allowed (1) the extraction and isolation of different information from the same signals, obtained through the modeling of different cognitive categories (sustained attention and working memory), and (2) the evaluation of model fitness, by inspection and comparison of residuals (i.e., unmodeled part of the signal) obtained in the two different cases. Results attest to the presence of a persistent attentional-related metabolic activity, superimposed to a task-related mnemonic contribution. Some hemispherical differences have also been highlighted frontally: deoxy-hemoglobin changes manifested a strong right lateralization, whereas modifications in oxy- and total hemoglobin showed a medial localization. The present work successfully explored the capability of fNIRS to detect the two neurophysiological categories under investigation and distinguish their activation patterns.

  9. Rancière, Marx and Claudette Colvin: Time, Knowledge, Memory and Strategy of Politics

    Directory of Open Access Journals (Sweden)

    Anders Fjeld

    2015-01-01

    Full Text Available How does Jacques Rancière construct a democratic approach to politics through his critique of Marxism as a “metapolitics”? I will develop the hypothesis that Rancière reconfigures the Marxist political subject by disconnecting it from its metapolitics, searching to think it rather in terms of improper excess, untimeliness and the force to forget. I will then define how Rancière rethinks the concepts of time and knowledge, opening questions left in suspense in his thought on memory, strategy and power – questions that might belong to a more experimental and existential register. I will develop these questions through a study on the black movement in 1955-56 in Montgomery, Alabama.

  10. Looking back in time: self-concept change affects visual perspective in autobiographical memory.

    Science.gov (United States)

    Libby, Lisa K; Eibach, Richard P

    2002-02-01

    People who change often report that their old selves seem like "different people." Correlational (Study 1) and experimental (Studies 2 and 3) studies showed that participants tended to use a 3rd-person observer perspective when visualizing memories of actions that conflicted with their current self-concept. A similar pattern emerged when participants imagined performing actions that varied in self-concept compatibility (Study 4). The authors conclude that on-line judgments of an action's self-concept compatibility affect the perspective used for image construction. Study 5 shows applied implications. Use of the 3rd-person perspective when recalling past episodes of overindulgent eating was related to optimism about behaving differently at an upcoming Thanksgiving dinner. The authors discuss the effect of self-concept compatibility on cognitive and emotional reactions to past actions and consider the role of causal attributions in defining the self across time.

  11. Spike-timing dependent plasticity in a transistor-selected resistive switching memory

    International Nuclear Information System (INIS)

    Ambrogio, S; Balatti, S; Nardi, F; Facchinetti, S; Ielmini, D

    2013-01-01

    In a neural network, neuron computation is achieved through the summation of input signals fed by synaptic connections. The synaptic activity (weight) is dictated by the synchronous firing of neurons, inducing potentiation/depression of the synaptic connection. This learning function can be supported by the resistive switching memory (RRAM), which changes its resistance depending on the amplitude, the pulse width and the bias polarity of the applied signal. This work shows a new synapse circuit comprising a MOS transistor as a selector and a RRAM as a variable resistance, displaying spike-timing dependent plasticity (STDP) similar to the one originally experienced in biological neural networks. We demonstrate long-term potentiation and long-term depression by simulations with an analytical model of resistive switching. Finally, the experimental demonstration of the new STDP scheme is presented. (paper)

  12. Unsupervised learning by spike timing dependent plasticity in phase change memory (PCM synapses

    Directory of Open Access Journals (Sweden)

    Stefano eAmbrogio

    2016-03-01

    Full Text Available We present a novel one-transistor/one-resistor (1T1R synapse for neuromorphic networks, based on phase change memory (PCM technology. The synapse is capable of spike-timing dependent plasticity (STDP, where gradual potentiation relies on set transition, namely crystallization, in the PCM, while depression is achieved via reset or amorphization of a chalcogenide active volume. STDP characteristics are demonstrated by experiments under variable initial conditions and number of pulses. Finally, we support the applicability of the 1T1R synapse for learning and recognition of visual patterns by simulations of fully connected neuromorphic networks with 2 or 3 layers with high recognition efficiency. The proposed scheme provides a feasible low-power solution for on-line unsupervised machine learning in smart reconfigurable sensors.

  13. Time-Based Loss in Visual Short-Term Memory Is from Trace Decay, Not Temporal Distinctiveness

    Science.gov (United States)

    Ricker, Timothy J.; Spiegel, Lauren R.; Cowan, Nelson

    2014-01-01

    There is no consensus as to why forgetting occurs in short-term memory tasks. In past work, we have shown that forgetting occurs with the passage of time, but there are 2 classes of theories that can explain this effect. In the present work, we investigate the reason for time-based forgetting by contrasting the predictions of temporal…

  14. Memory controllers for high-performance and real-time MPSoCs : requirements, architectures, and future trends

    NARCIS (Netherlands)

    Akesson, K.B.; Huang, Po-Chun; Clermidy, F.; Dutoit, D.; Goossens, K.G.W.; Chang, Yuan-Hao; Kuo, Tei-Wei; Vivet, P.; Wingard, D.

    2011-01-01

    Designing memory controllers for complex real-time and high-performance multi-processor systems-on-chip is challenging, since sufficient capacity and (real-time) performance must be provided in a reliable manner at low cost and with low power consumption. This special session contains four

  15. Psychological detachment from work during non-work time: linear or curvilinear relations with mental health and work engagement?

    Science.gov (United States)

    Shimazu, Akihito; Matsudaira, Ko; Jonge, Jan DE; Tosaka, Naoya; Watanabe, Kazuhiro; Takahashi, Masaya

    2016-06-10

    This study examined whether a higher level of psychological detachment during non-work time is associated with better employee mental health (Hypothesis 1), and examined whether psychological detachment has a curvilinear relation (inverted U-shaped pattern) with work engagement (Hypothesis 2). A large cross-sectional Internet survey was conducted among registered monitors of an Internet survey company in Japan. The questionnaire included scales for psychological detachment, employee mental health, and work engagement as well as for job characteristics and demographic variables as potential confounders. The hypothesized model was tested with moderated structural equation modeling techniques among 2,234 respondents working in the tertiary industries with regular employment. Results showed that psychological detachment had curvilinear relations with mental health as well as with work engagement. Mental health improved when psychological detachment increased from a low to higher levels but did not benefit any further from extremely high levels of psychological detachment. Work engagement showed the highest level at an intermediate level of detachment (inverted U-shaped pattern). Although high psychological detachment may enhance employee mental health, moderate levels of psychological detachment are most beneficial for his or her work engagement.

  16. 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.

  17. 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...

  18. Is it time to use checklists in mental health care auditing?

    Science.gov (United States)

    Abramowitz, Moshe Z; Polackiewicz, Jacob; Grinshpoon, Alexander

    2011-02-22

    A key strategy for improving the quality of mental health care is the design and implementation of a mechanism for on-site inspection and clinical auditing. We discuss the use of checklists in auditing providing an objective, comprehensive system for recording and analyzing multi-disciplinary, clinical auditing in mental health services. We believe such an approach can identify potential risks and allow for better decision making.

  19. Is it time to use checklists in mental health care auditing?

    OpenAIRE

    Jacob Polackiewicz; Alexander Grinshpoon; Moshe Z. Abramowitz

    2011-01-01

    A key strategy for improving the quality of mental health care is the design and implementation of a mechanism for on-site inspection and clinical auditing. We discuss the use of checklists in auditing providing an objective, comprehensive system for recording and analyzing multi-disciplinary, clinical auditing in mental health services. We believe such an approach can identify potential risks and allow for better decision making.

  20. Robust and Adaptive Online Time Series Prediction with Long Short-Term Memory

    Directory of Open Access Journals (Sweden)

    Haimin Yang

    2017-01-01

    Full Text Available Online time series prediction is the mainstream method in a wide range of fields, ranging from speech analysis and noise cancelation to stock market analysis. However, the data often contains many outliers with the increasing length of time series in real world. These outliers can mislead the learned model if treated as normal points in the process of prediction. To address this issue, in this paper, we propose a robust and adaptive online gradient learning method, RoAdam (Robust Adam, for long short-term memory (LSTM to predict time series with outliers. This method tunes the learning rate of the stochastic gradient algorithm adaptively in the process of prediction, which reduces the adverse effect of outliers. It tracks the relative prediction error of the loss function with a weighted average through modifying Adam, a popular stochastic gradient method algorithm for training deep neural networks. In our algorithm, the large value of the relative prediction error corresponds to a small learning rate, and vice versa. The experiments on both synthetic data and real time series show that our method achieves better performance compared to the existing methods based on LSTM.

  1. Robust and Adaptive Online Time Series Prediction with Long Short-Term Memory.

    Science.gov (United States)

    Yang, Haimin; Pan, Zhisong; Tao, Qing

    2017-01-01

    Online time series prediction is the mainstream method in a wide range of fields, ranging from speech analysis and noise cancelation to stock market analysis. However, the data often contains many outliers with the increasing length of time series in real world. These outliers can mislead the learned model if treated as normal points in the process of prediction. To address this issue, in this paper, we propose a robust and adaptive online gradient learning method, RoAdam (Robust Adam), for long short-term memory (LSTM) to predict time series with outliers. This method tunes the learning rate of the stochastic gradient algorithm adaptively in the process of prediction, which reduces the adverse effect of outliers. It tracks the relative prediction error of the loss function with a weighted average through modifying Adam, a popular stochastic gradient method algorithm for training deep neural networks. In our algorithm, the large value of the relative prediction error corresponds to a small learning rate, and vice versa. The experiments on both synthetic data and real time series show that our method achieves better performance compared to the existing methods based on LSTM.

  2. 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

  3. 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

  4. Adolescents with mental disorders while serving time and being subjected to socio-educative measures

    Directory of Open Access Journals (Sweden)

    Natália Pereira Gonçalves Vilarins

    2014-03-01

    Full Text Available This article examines how adolescent offenders with mental disorders are treated by socio-educative internment treatment. These adolescents come under the aegis of medicine and justice in a contradictory relationship between full protection, vulnerability of a developing person with a mental disorder and a juvenile delinquency offense. In this respect, the legal punishment prevails to the detriment of health care. After approval of the research project by an Ethics Research Committee, field research was conducted in the Youth Detention Unit of the Pilot Plan of the Brazilian Federal District. Data were collected through research of documents involving 35 medical records of adolescent users of psychotropic drugs in 2010, as well as participant observation and semi-structured interviews with professionals from the Youth Detention Unit and adolescent judiciary. In the review of the care provided to adolescent offenders with mental disorders under the childhood and youth policy and the mental health policy, it was revealed that the mental health care provided in the Youth Detention Unit or in the external mental health care services involved the prescription of medication.

  5. Real-time learning of predictive recognition categories that chunk sequences of items stored in working memory

    Directory of Open Access Journals (Sweden)

    Stephen eGrossberg

    2014-10-01

    Full Text Available How are sequences of events that are temporarily stored in a cognitive working memory unitized, or chunked, through learning? Such sequential learning is needed by the brain in order to enable language, spatial understanding, and motor skills to develop. In particular, how does the brain learn categories, or list chunks, that become selectively tuned to different temporal sequences of items in lists of variable length as they are stored in working memory, and how does this learning process occur in real time? The present article introduces a neural model that simulates learning of such list chunks. In this model, sequences of items are temporarily stored in an Item-and-Order, or competitive queuing, working memory before learning categorizes them using a categorization network, called a Masking Field, which is a self-similar, multiple-scale, recurrent on-center off-surround network that can weigh the evidence for variable-length sequences of items as they are stored in the working memory through time. A Masking Field hereby activates the learned list chunks that represent the most predictive item groupings at any time, while suppressing less predictive chunks. In a network with a given number of input items, all possible ordered sets of these item sequences, up to a fixed length, can be learned with unsupervised or supervised learning. The self-similar multiple-scale properties of Masking Fields interacting with an Item-and-Order working memory provide a natural explanation of George Miller's Magical Number Seven and Nelson Cowan's Magical Number Four. The article explains why linguistic, spatial, and action event sequences may all be stored by Item-and-Order working memories that obey similar design principles, and thus how the current results may apply across modalities. Item-and-Order properties may readily be extended to Item-Order-Rank working memories in which the same item can be stored in multiple list positions, or ranks, as in the list

  6. Remembering the best and worst of times: memories for extreme outcomes bias risky decisions.

    Science.gov (United States)

    Madan, Christopher R; Ludvig, Elliot A; Spetch, Marcia L

    2014-06-01

    When making decisions on the basis of past experiences, people must rely on their memories. Human memory has many well-known biases, including the tendency to better remember highly salient events. We propose an extreme-outcome rule, whereby this memory bias leads people to overweight the largest gains and largest losses, leading to more risk seeking for relative gains than for relative losses. To test this rule, in two experiments, people repeatedly chose between fixed and risky options, where the risky option led equiprobably to more or less than did the fixed option. As was predicted, people were more risk seeking for relative gains than for relative losses. In subsequent memory tests, people tended to recall the extreme outcome first and also judged the extreme outcome as having occurred more frequently. Across individuals, risk preferences in the risky-choice task correlated with these memory biases. This extreme-outcome rule presents a novel mechanism through which memory influences decision making.

  7. [Examination of the optimal midazolam dose required for loss of puncture memory at the time of spinal anesthesia].

    Science.gov (United States)

    Boku, Aiji; Koyama, Shinichi; Kishimoto, Naotaka; Nakatani, Keiji; Kurita, Satoshi; Nagata, Noboru; Niwa, Hitoshi

    2011-08-01

    We examined midazolam ED50 according to age that was necessary for loss of puncture memory at the time of spinal anesthesia and determined whether we could estimate the presence of puncture memory from the degree of sedation after midazolam administration. We enrolled patients with ASA PS 1 or 2 and patients from 50 to 80 years of age who had been planned for surgery with spinal anesthesia. We divided the patients into groups according to their age--50s, 60s, and 70s as L, M, and H groups, respectively. We evaluated the degree of sedation with six phases of scores after intravenous administration of midazolam and spinal anesthesia was performed. The midazolam dose was based on the ups and downs method. The midazolam ED50s required for the loss of puncture memory in groups L, M, and H were 0.043, 0.035, and 0.026 mg x kg(-1), respectively. We estimated the association between the sedation degree score after midazolam administration and the puncture memory from ROC curve, but AUC was 0.56 for all cases. The midazolam ED50 required for the loss of puncture memory decreased with age but it was difficult to estimate puncture memory from the degree of sedation.

  8. Anisomycin administered in the olfactory bulb and dorsal hippocampus impaired social recognition memory consolidation in different time-points.

    Science.gov (United States)

    Pena, R R; Pereira-Caixeta, A R; Moraes, M F D; Pereira, G S

    2014-10-01

    To identify an individual as familiar, rodents form a specific type of memory named social recognition memory. The olfactory bulb (OB) is an important structure for social recognition memory, while the hippocampus recruitment is still controversial. The present study was designed to elucidate the OB and the dorsal hippocampus contribution to the consolidation of social memory. For that purpose, we tested the effect of anisomycin (ANI), which one of the effects is the inhibition of protein synthesis, on the consolidation of social recognition memory. Swiss adult mice with cannulae implanted into the CA1 region of the dorsal hippocampus or into the OB were exposed to a juvenile during 5 min (training session; TR), and once again 1.5 h or 24 h later to test social short-term memory (S-STM) or social long-term memory (S-LTM), respectively. To study S-LTM consolidation, mice received intra-OB or intra-CA1 infusion of saline or ANI immediately, 3, 6 or 18 h after TR. ANI impaired S-LTM consolidation in the OB, when administered immediately or 6h after TR. In the dorsal hippocampus, ANI was amnesic only if administered 3 h after TR. Furthermore, the infusion of ANI in either OB or CA1, immediately after training, did not affect S-STM. Moreover, ANI administered into the OB did not alter the animal's performance in the buried food-finding task. Altogether, our results suggest the consolidation of S-LTM requires both OB and hippocampus participation, although in different time points. This study may help shedding light on the specific roles of the OB and dorsal hippocampus in social recognition memory. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Cortisol effects on autobiographic memory retrieval in PTSD: an analysis of word valence and time until retrieval.

    Science.gov (United States)

    Wingenfeld, Katja; Driessen, Martin; Schlosser, Nicole; Terfehr, Kirsten; Carvalho Fernando, Silvia; Wolf, Oliver Tobias

    2013-09-01

    In healthy participants, cortisol administration has been found to impair autobiographic memory retrieval. We recently reported that administration of 10 mg of hydrocortisone had enhancing effects on autobiographical memory retrieval, i.e. more specific memory retrieval, in patients with posttraumatic stress disorder (PTSD), while in healthy controls the impairing effects were replicated. We here report a re-analysis of these data with respect to cue-word valence and retrieval time. In a placebo-controlled cross-over study, 43 patients with PTSD and 43 age- and sex-matched healthy controls received either placebo or hydrocortisone orally before the autobiographical memory test was performed. We found that the effects of cortisol on memory retrieval depended on cue-word valence and group (significant interaction effects of drug by group and drug by valence by group). The enhancing effect of cortisol on memory retrieval in PTSD seemed to be relatively independent of cue-word valence, while in the control group the impairing effects of cortisol were only seen in response to neutral cue-words. The second result of the study was that in patients as well as in controls, cortisol administration led to faster memory retrieval compared to placebo. This was seen in response to positive and (to lesser extend) to neutral cue-words, but not in response to negative cue-words. Our findings illustrate that the opposing effects of cortisol on autobiographical memory retrieval in PTSD patients and controls are further modulated by the emotionality of the cue-words.

  10. Identifying the appropriate time for deep brain stimulation to achieve spatial memory improvement on the Morris water maze.

    Science.gov (United States)

    Jeong, Da Un; Lee, Jihyeon; Chang, Won Seok; Chang, Jin Woo

    2017-03-07

    The possibility of using deep brain stimulation (DBS) for memory enhancement has recently been reported, but the precise underlying mechanisms of its effects remain unknown. Our previous study suggested that spatial memory improvement by medial septum (MS)-DBS may be associated with cholinergic regulation and neurogenesis. However, the affected stage of memory could not be distinguished because the stimulation was delivered during the execution of all memory processes. Therefore, this study was performed to determine the stage of memory affected by MS-DBS. Rats were administered 192 IgG-saporin to lesion cholinergic neurons. Stimulation was delivered at different times in different groups of rats: 5 days before the Morris water maze test (pre-stimulation), 5 days during the training phase of the Morris water maze test (training-stimulation), and 2 h before the Morris water maze probe test (probe-stimulation). A fourth group of rats was lesioned but received no stimulation. These four groups were compared with a normal (control) group. The most effective memory restoration occurred in the pre-stimulation group. Moreover, the pre-stimulation group exhibited better recall of the platform position than the other stimulation groups. An increase in the level of brain derived neurotrophic factor (BDNF) was observed in the pre-stimulation group; this increase was maintained for 1 week. However, acetylcholinesterase activity in the pre-stimulation group was not significantly different from the lesion group. Memory impairment due to cholinergic denervation can be improved by DBS. The improvement is significantly correlated with the up-regulation of BDNF expression and neurogenesis. Based on the results of this study, the use of MS-DBS during the early stage of disease may restore spatial memory impairment.

  11. On the research of time past: the hunt for the substrate of memory.

    Science.gov (United States)

    Queenan, Bridget N; Ryan, Tomás J; Gazzaniga, Michael S; Gallistel, Charles R

    2017-05-01

    The search for memory is one of the oldest quests in written human history. For at least two millennia, we have tried to understand how we learn and remember. We have gradually converged on the brain and looked inside it to find the basis of knowledge, the trace of memory. The search for memory has been conducted on multiple levels, from the organ to the cell to the synapse, and has been distributed across disciplines with less chronological or intellectual overlap than one might hope. Frequently, the study of the mind and its memories has been severely restricted by technological or philosophical limitations. However, in the last few years, certain technologies have emerged, offering new routes of inquiry into the basis of memory. The 2016 Kavli Futures Symposium was devoted to the past and future of memory studies. At the workshop, participants evaluated the logic and data underlying the existing and emerging theories of memory. In this paper, written in the spirit of the workshop, we briefly review the history of the hunt for memory, summarizing some of the key debates at each level of spatial resolution. We then discuss the exciting new opportunities to unravel the mystery of memory. © 2017 New York Academy of Sciences.

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

    Science.gov (United States)

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

    2014-01-01

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

  13. HOW DO EPISODIC AND SEMANTIC MEMORY CONTRIBUTE TO EPISODIC FORESIGHT IN YOUNG CHILDREN?

    Directory of Open Access Journals (Sweden)

    Gema eMartin Ordas

    2014-07-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  15. The importance of source and cue type in time-based everyday prospective memory.

    Science.gov (United States)

    Oates, Joyce M; Peynircioğlu, Zehra F

    2014-01-01

    We examined the effects of the source of a prospective memory task (provided or generated) and the type of cue (specific or general) triggering that task in everyday settings. Participants were asked to complete both generated and experimenter-provided tasks and to send a text message when each task was completed. The cue/context for the to-be-completed tasks was either a specific time or a general deadline (time-based cue), and the cue/context for the texting task was the completion of the task itself (activity-based cue). Although generated tasks were completed more often, generated cues/contexts were no more effective than provided ones in triggering the intention. Furthermore, generated tasks were completed more often when the cue/context comprised a specific time, whereas provided tasks were completed more often when the cue/context comprised a general deadline. However, texting was unaffected by the source of the cue/context. Finally, emotion modulated the effects. Results are discussed within a process-driven framework.

  16. ‘Like a Stone’: Ecology, Enargeia, and Ethical Time in Alice Oswald’s Memorial

    Directory of Open Access Journals (Sweden)

    Farrier, David

    2014-05-01

    Full Text Available This article argues that the Anthropocene is marked by haunted time. As the ‘geological agents’ of climate change, as Dipesh Chakrabarty has put it, we both identify with ‘deep time’ processes and conjure the ghosts of those whose lives to come will be shaped in drastic ways by our actions in the present. This article explores a poetics of haunted time via readings of the work of artist/sculptor Ilana Halperin and poet Alice Oswald. Halperin’s recent work with the “slow and fast time” of geological processes (calcification and lava flows, and also with the body’s own capacity to generate geologic material (in the form of body stones, engages with the possibility of “geologic intimacy.” From here, the article reads Memorial, Oswald’s recent translation of the Iliad pared down to snapshot biographies of the soldiers killed in the Trojan wars interleaved with a series of astonishing similes of the natural world, as an example of a poetics of haunted time. Drawing on James Hatley’s theory of ethical time and its ecocritical application by Deborah Bird Rose, I argue that Oswald’s strategy of repeating similes creates a kind of spectral echo, giving expression to an enfolding of diachronic and synchronous time in which intergenerational responsibilities are realised. The haunted time of Oswald’s poem thus represents a passage to the difficult intimacy of rethinking the relationship between past, present, and future actions and effects.

  17. Multi-parameter approach to evaluate the timing of memory status after 17DD-YF primary vaccination.

    Science.gov (United States)

    Costa-Pereira, Christiane; Campi-Azevedo, Ana Carolina; Coelho-Dos-Reis, Jordana Grazziela; Peruhype-Magalhães, Vanessa; Araújo, Márcio Sobreira Silva; do Vale Antonelli, Lis Ribeiro; Fonseca, Cristina Toscano; Lemos, Jandira Aparecida; Malaquias, Luiz Cosme Cote; de Souza Gomes, Matheus; Rodrigues Amaral, Laurence; Rios, Maria; Chancey, Caren; Persi, Harold Richard; Pereira, Jorge Marcelo; de Sousa Maia, Maria de Lourdes; Freire, Marcos da Silva; Martins, Reinaldo de Menezes; Homma, Akira; Simões, Marisol; Yamamura, Anna Yoshida; Farias, Roberto Henrique Guedes; Romano, Alessandro Pecego Martins; Domingues, Carla Magda; Tauil, Pedro Luiz; Vasconcelos, Pedro Fernando Costa; Caldas, Iramaya Rodrigues; Camacho, Luiz Antônio; Teixeira-Carvalho, Andrea; Martins-Filho, Olindo Assis

    2018-06-01

    In this investigation, machine-enhanced techniques were applied to bring about scientific insights to identify a minimum set of phenotypic/functional memory-related biomarkers for post-vaccination follow-up upon yellow fever (YF) vaccination. For this purpose, memory status of circulating T-cells (Naïve/early-effector/Central-Memory/Effector-Memory) and B-cells (Naïve/non-Classical-Memory/Classical-Memory) along with the cytokine profile (IFN/TNF/IL-5/IL-10) were monitored before-NV(day0) and at distinct time-points after 17DD-YF primary vaccination-PV(day30-45); PV(year1-9) and PV(year10-11). A set of biomarkers (eEfCD4; EMCD4; CMCD19; EMCD8; IFNCD4; IL-5CD8; TNFCD4; IFNCD8; TNFCD8; IL-5CD19; IL-5CD4) were observed in PV(day30-45), but not in NV(day0), with most of them still observed in PV(year1-9). Deficiencies of phenotypic/functional biomarkers were observed in NV(day0), while total lack of memory-related attributes was observed in PV(year10-11), regardless of the age at primary vaccination. Venn-diagram analysis pre-selected 10 attributes (eEfCD4, EMCD4, CMCD19, EMCD8, IFNCD4, IL-5CD8, TNFCD4, IFNCD8, TNFCD8 and IL-5CD4), of which the overall mean presented moderate accuracy to discriminate PV(day30-45)&PV(year1-9) from NV(day0)&PV(year10-11). Multi-parameter approaches and decision-tree algorithms defined the EMCD8 and IL-5CD4 attributes as the top-two predictors with moderated performance. Together with the PRNT titers, the top-two biomarkers led to a resultant memory status observed in 80% and 51% of volunteers in PV(day30-45) and PV(year1-9), contrasting with 0% and 29% found in NV(day0) and PV(year10-11), respectively. The deficiency of memory-related attributes observed at PV(year10-11) underscores the conspicuous time-dependent decrease of resultant memory following17DD-YF primary vaccination that could be useful to monitor potential correlates of protection in areas under risk of YF transmission.

  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. Transitions between child and adult mental health services: service design, philosophy and meaning at uncertain times.

    Science.gov (United States)

    Murcott, W J

    2014-09-01

    A young person's transition of care from child and adolescent mental health services to adult mental health services can be an uncertain and distressing event that can have serious ramifications for their recovery. Recognition of this across many countries and recent UK media interest in the dangers of mental health services failing young people has led practitioners to question the existing processes. This paper reviews the current theories and research into potential failings of services and encourages exploration for a deeper understanding of when and how care should be managed in the transition process for young people. Mental health nurses can play a vital role in this process and, by adopting the assumptions of this paradigm, look at transition from this unique perspective. By reviewing the current ideas related to age boundaries, service thresholds, service philosophy and service design, it is argued that the importance of the therapeutic relationship, the understanding of the cultural context of the young person and the placing of the young person in a position of autonomy and control should be central to any decision and process of transfer between two mental health services. © 2014 John Wiley & Sons Ltd.

  20. Real-time tumor motion estimation using respiratory surrogate via memory-based learning

    Science.gov (United States)

    Li, Ruijiang; Lewis, John H.; Berbeco, Ross I.; Xing, Lei

    2012-08-01

    Respiratory tumor motion is a major challenge in radiation therapy for thoracic and abdominal cancers. Effective motion management requires an accurate knowledge of the real-time tumor motion. External respiration monitoring devices (optical, etc) provide a noninvasive, non-ionizing, low-cost and practical approach to obtain the respiratory signal. Due to the highly complex and nonlinear relations between tumor and surrogate motion, its ultimate success hinges on the ability to accurately infer the tumor motion from respiratory surrogates. Given their widespread use in the clinic, such a method is critically needed. We propose to use a powerful memory-based learning method to find the complex relations between tumor motion and respiratory surrogates. The method first stores the training data in memory and then finds relevant data to answer a particular query. Nearby data points are assigned high relevance (or weights) and conversely distant data are assigned low relevance. By fitting relatively simple models to local patches instead of fitting one single global model, it is able to capture highly nonlinear and complex relations between the internal tumor motion and external surrogates accurately. Due to the local nature of weighting functions, the method is inherently robust to outliers in the training data. Moreover, both training and adapting to new data are performed almost instantaneously with memory-based learning, making it suitable for dynamically following variable internal/external relations. We evaluated the method using respiratory motion data from 11 patients. The data set consists of simultaneous measurement of 3D tumor motion and 1D abdominal surface (used as the surrogate signal in this study). There are a total of 171 respiratory traces, with an average peak-to-peak amplitude of ∼15 mm and average duration of ∼115 s per trace. Given only 5 s (roughly one breath) pretreatment training data, the method achieved an average 3D error of 1.5 mm and 95

  1. Real-time tumor motion estimation using respiratory surrogate via memory-based learning

    International Nuclear Information System (INIS)

    Li Ruijiang; Xing Lei; Lewis, John H; Berbeco, Ross I

    2012-01-01

    Respiratory tumor motion is a major challenge in radiation therapy for thoracic and abdominal cancers. Effective motion management requires an accurate knowledge of the real-time tumor motion. External respiration monitoring devices (optical, etc) provide a noninvasive, non-ionizing, low-cost and practical approach to obtain the respiratory signal. Due to the highly complex and nonlinear relations between tumor and surrogate motion, its ultimate success hinges on the ability to accurately infer the tumor motion from respiratory surrogates. Given their widespread use in the clinic, such a method is critically needed. We propose to use a powerful memory-based learning method to find the complex relations between tumor motion and respiratory surrogates. The method first stores the training data in memory and then finds relevant data to answer a particular query. Nearby data points are assigned high relevance (or weights) and conversely distant data are assigned low relevance. By fitting relatively simple models to local patches instead of fitting one single global model, it is able to capture highly nonlinear and complex relations between the internal tumor motion and external surrogates accurately. Due to the local nature of weighting functions, the method is inherently robust to outliers in the training data. Moreover, both training and adapting to new data are performed almost instantaneously with memory-based learning, making it suitable for dynamically following variable internal/external relations. We evaluated the method using respiratory motion data from 11 patients. The data set consists of simultaneous measurement of 3D tumor motion and 1D abdominal surface (used as the surrogate signal in this study). There are a total of 171 respiratory traces, with an average peak-to-peak amplitude of ∼15 mm and average duration of ∼115 s per trace. Given only 5 s (roughly one breath) pretreatment training data, the method achieved an average 3D error of 1.5 mm and 95

  2. 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

  3. Rapid Forgetting Results from Competition over Time between Items in Visual Working Memory

    Science.gov (United States)

    Pertzov, Yoni; Manohar, Sanjay; Husain, Masud

    2017-01-01

    Working memory is now established as a fundamental cognitive process across a range of species. Loss of information held in working memory has the potential to disrupt many aspects of cognitive function. However, despite its significance, the mechanisms underlying rapid forgetting remain unclear, with intense recent debate as to whether it is…

  4. Can Planning Time Compensate for Individual Differences in Working Memory Capacity?

    Science.gov (United States)

    Nielson, Katharine B.

    2014-01-01

    Language learners with high working memory capacity have an advantage, all other factors being equal, during the second language acquisition (SLA) process; therefore, identifying a pedagogical intervention that can compensate for low working memory capacity would be advantageous to language learners and instructors. Extensive research on the…

  5. Differentiation and Response Bias in Episodic Memory: Evidence from Reaction Time Distributions

    Science.gov (United States)

    Criss, Amy H.

    2010-01-01

    In differentiation models, the processes of encoding and retrieval produce an increase in the distribution of memory strength for targets and a decrease in the distribution of memory strength for foils as the amount of encoding increases. This produces an increase in the hit rate and decrease in the false-alarm rate for a strongly encoded compared…

  6. Looking Inward and Back: Real-Time Monitoring of Visual Working Memories

    Science.gov (United States)

    Suchow, Jordan W.; Fougnie, Daryl; Alvarez, George A.

    2017-01-01

    Confidence in our memories is influenced by many factors, including beliefs about the perceptibility or memorability of certain kinds of objects and events, as well as knowledge about our skill sets, habits, and experiences. Notoriously, our knowledge and beliefs about memory can lead us astray, causing us to be overly confident in eyewitness…

  7. Analogical Reasoning in Adolescents with Intellectual Disability: Effects of External Memories and Time Processing

    Science.gov (United States)

    Denaes, Caroline; Berger, Jean-Louis

    2014-01-01

    Analogical reasoning involves the comparison of pictures as well as the memorisation of relations. Young children (4-7 years old) and students with moderate intellectual disability have a short memory span, which hampers them in succeeding traditional analogical tests. In the present study, we investigated if, by providing external memory hints,…

  8. Long-distance quantum communication over noisy networks without long-time quantum memory

    Science.gov (United States)

    Mazurek, Paweł; Grudka, Andrzej; Horodecki, Michał; Horodecki, Paweł; Łodyga, Justyna; Pankowski, Łukasz; PrzysieŻna, Anna

    2014-12-01

    The problem of sharing entanglement over large distances is crucial for implementations of quantum cryptography. A possible scheme for long-distance entanglement sharing and quantum communication exploits networks whose nodes share Einstein-Podolsky-Rosen (EPR) pairs. In Perseguers et al. [Phys. Rev. A 78, 062324 (2008), 10.1103/PhysRevA.78.062324] the authors put forward an important isomorphism between storing quantum information in a dimension D and transmission of quantum information in a D +1 -dimensional network. We show that it is possible to obtain long-distance entanglement in a noisy two-dimensional (2D) network, even when taking into account that encoding and decoding of a state is exposed to an error. For 3D networks we propose a simple encoding and decoding scheme based solely on syndrome measurements on 2D Kitaev topological quantum memory. Our procedure constitutes an alternative scheme of state injection that can be used for universal quantum computation on 2D Kitaev code. It is shown that the encoding scheme is equivalent to teleporting the state, from a specific node into a whole two-dimensional network, through some virtual EPR pair existing within the rest of network qubits. We present an analytic lower bound on fidelity of the encoding and decoding procedure, using as our main tool a modified metric on space-time lattice, deviating from a taxicab metric at the first and the last time slices.

  9. Long Short-Term Memory Neural Networks for Online Disturbance Detection in Satellite Image Time Series

    Directory of Open Access Journals (Sweden)

    Yun-Long Kong

    2018-03-01

    Full Text Available A satellite image time series (SITS contains a significant amount of temporal information. By analysing this type of data, the pattern of the changes in the object of concern can be explored. The natural change in the Earth’s surface is relatively slow and exhibits a pronounced pattern. Some natural events (for example, fires, floods, plant diseases, and insect pests and human activities (for example, deforestation and urbanisation will disturb this pattern and cause a relatively profound change on the Earth’s surface. These events are usually referred to as disturbances. However, disturbances in ecosystems are not easy to detect from SITS data, because SITS contain combined information on disturbances, phenological variations and noise in remote sensing data. In this paper, a novel framework is proposed for online disturbance detection from SITS. The framework is based on long short-term memory (LSTM networks. First, LSTM networks are trained by historical SITS. The trained LSTM networks are then used to predict new time series data. Last, the predicted data are compared with real data, and the noticeable deviations reveal disturbances. Experimental results using 16-day compositions of the moderate resolution imaging spectroradiometer (MOD13Q1 illustrate the effectiveness and stability of the proposed approach for online disturbance detection.

  10. Dynamical decoupling sequences for multi-qubit dephasing suppression and long-time quantum memory

    International Nuclear Information System (INIS)

    Paz-Silva, Gerardo A; Lee, Seung-Woo; Green, Todd J; Viola, Lorenza

    2016-01-01

    We consider a class of multi-qubit dephasing models that combine classical noise sources and linear coupling to a bosonic environment, and are controlled by arbitrary sequences of dynamical decoupling pulses. Building on a general transfer filter-function framework for open-loop control, we provide an exact representation of the controlled dynamics for arbitrary stationary non-Gaussian classical and quantum noise statistics, with analytical expressions emerging when all dephasing sources are Gaussian. This exact characterization is used to establish two main results. First, we construct multi-qubit sequences that ensure maximum high-order error suppression in both the time and frequency domain and that can be exponentially more efficient than existing ones in terms of total pulse number. Next, we show how long-time multi-qubit storage may be achieved by meeting appropriate conditions for the emergence of a fidelity plateau under sequence repetition, thereby generalizing recent results for single-qubit memory under Gaussian dephasing. In both scenarios, the key step is to endow multi-qubit sequences with a suitable displacement anti-symmetry property, which is of independent interest for applications ranging from environment-assisted entanglement generation to multi-qubit noise spectroscopy protocols. (paper)

  11. A 4-kbit low-cost antifuse one-time programmable memory macro for embedded applications

    International Nuclear Information System (INIS)

    Li Xian; Zhong Huicai; Jia Cheng; Li Xin

    2014-01-01

    A 4-kbit low-cost one-time programmable (OTP) memory macro for embedded applications is designed and implemented in a 0.18-μm standard CMOS process. The area of the proposed 1.5 transistor (1.5T) OTP cell is 2.13 μm 2 , which is a 49.3% size reduction compared to the previously reported cells. The 1.5T cell is fabricated and measured and shows a large programming window without any disturbance. A novel high voltage switch (HVSW) circuit is also proposed to make sure the OTP macro, implemented in a standard CMOS process, works reliably with the high program voltage. The OTP macro is embedded in negative radio frequency identification (RFID) tags. The full chip size, including the analog front-end, digital controller and the 4-kbit OTP macro, is 600 × 600 μm 2 . The 4-kbit OTP macro only consumes 200 × 260 μm 2 . The measurement shows a 100% program yield by adjusting the program time and has obvious advantages in the core area and power consumption compared to the reported 3T and 2T OTP cores. (semiconductor integrated circuits)

  12. Event- and time-triggered remembering: the impact of attention deficit hyperactivity disorder on prospective memory performance in children.

    Science.gov (United States)

    Talbot, Karley-Dale S; Kerns, Kimberly A

    2014-11-01

    The current study examined prospective memory (PM, both time-based and event-based) and time estimation (TR, a time reproduction task) in children with and without attention deficit hyperactivity disorder (ADHD). This study also investigated the influence of task performance and TR on time-based PM in children with ADHD relative to controls. A sample of 69 children, aged 8 to 13 years, completed the CyberCruiser-II time-based PM task, a TR task, and the Super Little Fisherman event-based PM task. PM performance was compared with children's TR abilities, parental reports of daily prospective memory disturbances (Prospective and Retrospective Memory Questionnaire for Children, PRMQC), and ADHD symptomatology (Conner's rating scales). Children with ADHD scored more poorly on event-based PM, time-based PM, and TR; interestingly, TR did not appear related to performance on time-based PM. In addition, it was found that PRMQC scores and ADHD symptom severity were related to performance on the time-based PM task but not to performance on the event-based PM task. These results provide some limited support for theories that propose a distinction between event-based PM and time-based PM. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Intelligibility and Clarity of Reverberant Speech: Effects of Wide Dynamic Range Compression Release Time and Working Memory

    Science.gov (United States)

    Reinhart, Paul N.; Souza, Pamela E.

    2016-01-01

    Purpose: The purpose of this study was to examine the effects of varying wide dynamic range compression (WDRC) release time on intelligibility and clarity of reverberant speech. The study also considered the role of individual working memory. Method: Thirty older listeners with mild to moderately-severe sloping sensorineural hearing loss…

  14. Distinct and shared cognitive functions mediate event- and time-based prospective memory impairment in normal ageing

    Science.gov (United States)

    Gonneaud, Julie; Kalpouzos, Grégoria; Bon, Laetitia; Viader, Fausto; Eustache, Francis; Desgranges, Béatrice

    2011-01-01

    Prospective memory (PM) is the ability to remember to perform an action at a specific point in the future. Regarded as multidimensional, PM involves several cognitive functions that are known to be impaired in normal aging. In the present study, we set out to investigate the cognitive correlates of PM impairment in normal aging. Manipulating cognitive load, we assessed event- and time-based PM, as well as several cognitive functions, including executive functions, working memory and retrospective episodic memory, in healthy subjects covering the entire adulthood. We found that normal aging was characterized by PM decline in all conditions and that event-based PM was more sensitive to the effects of aging than time-based PM. Whatever the conditions, PM was linked to inhibition and processing speed. However, while event-based PM was mainly mediated by binding and retrospective memory processes, time-based PM was mainly related to inhibition. The only distinction between high- and low-load PM cognitive correlates lays in an additional, but marginal, correlation between updating and the high-load PM condition. The association of distinct cognitive functions, as well as shared mechanisms with event- and time-based PM confirms that each type of PM relies on a different set of processes. PMID:21678154

  15. The neocortical network representing associative memory reorganizes with time in a process engaging the anterior temporal lobe.

    Science.gov (United States)

    Nieuwenhuis, Ingrid L C; Takashima, Atsuko; Oostenveld, Robert; McNaughton, Bruce L; Fernández, Guillén; Jensen, Ole

    2012-11-01

    During encoding, the distributed neocortical representations of memory components are presumed to be associatively linked by the hippocampus. With time, a reorganization of brain areas supporting memory takes place, which can ultimately result in memories becoming independent of the hippocampus. While it is theorized that with time, the neocortical representations become linked by higher order neocortical association areas, this remains to be experimentally supported. In this study, 24 human participants encoded sets of face-location associations, which they retrieved 1 or 25 h later ("recent" and "remote" conditions, respectively), while their brain activity was recorded using whole-head magnetoencephalography. We investigated changes in the functional interactions between the neocortical representational areas emerging over time. To assess functional interactions, trial-by-trial high gamma (60-140 Hz) power correlations were calculated between the neocortical representational areas relevant to the encoded information, namely the fusiform face area (FFA) and posterior parietal cortex (PPC). With time, both the FFA and the PPC increased their functional interactions with the anterior temporal lobe (ATL). Given that the ATL is involved in semantic representation of paired associates, our results suggest that, already within 25 h after acquiring new memory associations, neocortical functional links are established via higher order semantic association areas.

  16. Evaluation of a Connectionless NoC for a Real-Time Distributed Shared Memory Many-Core System

    NARCIS (Netherlands)

    Rutgers, J.H.; Bekooij, Marco Jan Gerrit; Smit, Gerardus Johannes Maria

    2012-01-01

    Real-time embedded systems like smartphones tend to comprise an ever increasing number of processing cores. For scalability and the need for guaranteed performance, the use of a connection-oriented network-on-chip (NoC) is advocated. Furthermore, a distributed shared memory architecture is preferred

  17. 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...

  18. Time perception impairment in early-to-moderate stages of Huntington's disease is related to memory deficits.

    Science.gov (United States)

    Righi, Stefania; Galli, Luca; Paganini, Marco; Bertini, Elisabetta; Viggiano, Maria Pia; Piacentini, Silvia

    2016-01-01

    Huntington's disease (HD) primarily affects striatum and prefrontal dopaminergic circuits which are fundamental neural correlates of the timekeeping mechanism. The few studies on HD mainly investigated motor timing performance in second durations. The present work explored time perception in early-to-moderate symptomatic HD patients for seconds and milliseconds with the aim to clarify which component of the scalar expectancy theory (SET) is mainly responsible for HD timing defect. Eleven HD patients were compared to 11 controls employing two separate temporal bisection tasks in second and millisecond ranges. Our results revealed the same time perception deficits for seconds and milliseconds in HD patients. Time perception impairment in early-to-moderate stages of Huntington's disease is related to memory deficits. Furthermore, both the non-systematical defect of temporal sensitivity and the main impairment of timing performance in the extreme value of the psychophysical curves suggested an HD deficit in the memory component of the SET. This result was further confirmed by the significant correlations between time perception performance and long-term memory test scores. Our findings added important preliminary data for both a deeper comprehension of HD time-keeping deficits and possible implications on neuro-rehabilitation practices.

  19. Analog memory and spike-timing-dependent plasticity characteristics of a nanoscale titanium oxide bilayer resistive switching device

    International Nuclear Information System (INIS)

    Seo, Kyungah; Park, Sangsu; Lee, Kwanghee; Lee, Byounghun; Hwang, Hyunsang; Kim, Insung; Jung, Seungjae; Jo, Minseok; Park, Jubong; Shin, Jungho; Biju, Kuyyadi P; Kong, Jaemin

    2011-01-01

    We demonstrated analog memory, synaptic plasticity, and a spike-timing-dependent plasticity (STDP) function with a nanoscale titanium oxide bilayer resistive switching device with a simple fabrication process and good yield uniformity. We confirmed the multilevel conductance and analog memory characteristics as well as the uniformity and separated states for the accuracy of conductance change. Finally, STDP and a biological triple model were analyzed to demonstrate the potential of titanium oxide bilayer resistive switching device as synapses in neuromorphic devices. By developing a simple resistive switching device that can emulate a synaptic function, the unique characteristics of synapses in the brain, e.g. combined memory and computing in one synapse and adaptation to the outside environment, were successfully demonstrated in a solid state device.

  20. Strong memory in time series of human magnetoencephalograms can identify photosensitive epilepsy

    International Nuclear Information System (INIS)

    Yulmetyev, R. M.; Yulmetyeva, D. G.; Haenggi, P.; Shimojo, S.; Bhattacharya, J.

    2007-01-01

    To discuss the salient role of statistical memory effects in human brain functioning, we have analyzed a set of stochastic memory quantifiers that reflects the dynamical characteristics of neuromagnetic responses of magnetoencephalographic signals to a flickering stimulus of different color combinations from a group of control subjects, and compared them with those for a patient with photosensitive epilepsy. We have discovered that the emergence of strong memory and the accompanying transition to a regular and robust regime of chaotic behavior of signals in separate areas for a patient most likely identifies the regions where the protective mechanism against the occurrence of photosensitive epilepsy is located