WorldWideScience

Sample records for current cognitive models

  1. Cognitive mechanisms of mindfulness: A test of current models.

    Science.gov (United States)

    Isbel, Ben; Mahar, Doug

    2015-12-15

    Existing models of mindfulness describe the self-regulation of attention as primary, leading to enhanced decentering and ability to access and override automatic cognitive processes. This study compared 23 experienced and 21 non-meditators on tests of mindfulness, attention, decentering, and ability to override automatic cognitive processes to test the cognitive mechanisms proposed to underlie mindfulness practice. Experienced meditators had significantly higher mindfulness and decentering than non-meditators. No significant difference between groups was found on measures of attention or ability to override automatic processes. These findings support the prediction that mindfulness leads to enhanced decentering, but do not support the cognitive mechanisms proposed to underlie such enhancement. Since mindfulness practice primarily involves internally directed attention, it may be the case that cognitive tests requiring externally directed attention and timed responses do not accurately assess mindfulness-induced cognitive changes. Implications for the models of mindfulness and future research are discussed.

  2. Current Developments in Cognitive Linguistics

    Institute of Scientific and Technical Information of China (English)

    Dirk Geeraerts

    2008-01-01

    After 30 years of theoretical development, we need to address the question whether the internal evolution of Cognitive Linguistics can be synthesized: what are the fundamental underlying trends in Cognitive Linguistics, and how do they shape the current developments within Cognitive Linguistics? This paper argues that Cognitive Linguistics is essentially characterized by a gradual recontextualization of the grammar. First, the development of 20th century grammar is characterized by a succession of a decontextualizing and a recontextualizing movement. Second, the various stages in the development of Cognitive Linguistics involve the gradual recovery of the various types of context that were discarded by generative grammar. These involve the experiential and embodied context of meaning in natural Language, the pragmatic context of actual language usage, and the social and cultural context of language as a shared code.

  3. A cognitive model's view of animal cognition

    Directory of Open Access Journals (Sweden)

    Sidney D'MELLO, Stan FRANKLIN

    2011-08-01

    Full Text Available Although it is a relatively new field of study, the animal cognition literature is quite extensive and difficult to synthesize. This paper explores the contributions a comprehensive, computational, cognitive model can make toward organizing and assimilating this literature, as well as toward identifying important concepts and their interrelations. Using the LIDA model as an example, a framework is described within which to integrate the diverse research in animal cognition. Such a framework can provide both an ontology of concepts and their relations, and a working model of an animal’s cognitive processes that can compliment active empirical research. In addition to helping to account for a broad range of cognitive processes, such a model can help to comparatively assess the cognitive capabilities of different animal species. After deriving an ontology for animal cognition from the LIDA model, we apply it to develop the beginnings of a database that maps the cognitive facilities of a variety of animal species. We conclude by discussing future avenues of research, particularly the use of computational models of animal cognition as valuable tools for hypotheses generation and testing [Current Zoology 57 (4: 499–513, 2011].

  4. Non Pharmacological Cognitive Enhancers - Current Perspectives.

    Science.gov (United States)

    Sachdeva, Ankur; Kumar, Kuldip; Anand, Kuljeet Singh

    2015-07-01

    Cognition refers to the mental processes involved in thinking, knowing, remembering, judging, and problem solving. Cognitive dysfunctions are an integral part of neuropsychiatric disorders as well as in healthy ageing. Cognitive Enhancers are molecules that help improve aspects of cognition like memory, intelligence, motivation, attention and concentration. Recently, Non Pharmacological Cognitive Enhancers have gained popularity as effective and safe alternative to various established drugs. Many of these Non Pharmacological Cognitive Enhancers seem to be more efficacious compared to currently available Pharmacological Cognitive Enhancers. This review describes and summarizes evidence on various Non Pharmacological Cognitive Enhancers such as physical exercise, sleep, meditation and yoga, spirituality, nutrients, computer training, brain stimulation, and music. We also discuss their role in ageing and different neuro-psychiatric disorders, and current status of Cochrane database recommendations. We searched the Pubmed database for the articles and reviews having the terms 'non pharmacological and cognitive' in the title, published from 2000 till 2014. A total of 11 results displayed, out of which 10 were relevant to the review. These were selected and reviewed. Appropriate cross-references within the articles along with Cochrane reviews were also considered and studied.

  5. Current therapy for cognitive impairments

    Directory of Open Access Journals (Sweden)

    Natalia Vasilyevna Vakhnina

    2011-01-01

    Full Text Available Cognitive impairments (CIs are a highly common type of neurological disorders particularly in elderly patients. Choice of a therapeutic strategy for CI is determined by the etiology of abnormalities and their degree. Measures to prevent CI progression and dementia: adequate treatment of existing cardiovascular diseases, prevention of stroke, balanced nutrition, moderate physical and intellectual exercises, and combatting overweight and low activity are of basic value in treating mild and moderate CIs. According to the data of a number of investigations, the above measures reduce the risk of dementia, including in the genetically predisposed. Pharmacotherapy for mild and moderate CIs generally comprises vasoactive, neurometabolic, and noradrenergic agents. The indication for the use of memantine and/or acetylcholinergic agents, i.e. basic therapy for the most common forms of dementia (Alzheimer's disease, Lewy body dementia, vascular, and mixed dementia, hepatic colics is severe CIs. The long-term use of memantine and/or acetylcholinergic agents alleviates the cognitive and behavioral symptoms of dementia, enhances self-dependence in patients, and prolongs their active lifetime.

  6. Cognitive impairment and preferences for current health

    Directory of Open Access Journals (Sweden)

    Tsevat Joel

    2009-01-01

    Full Text Available Abstract Background We assessed preferences for current health using the visual analogue scale (VAS, standard gamble (SG, time trade-off (TTO, and willingness to pay (WTP in patients with cerebral aneurysms, a population vulnerable to cognitive deficits related to aneurysm bleeding or treatment. Methods We measured VAS, SG, TTO, and WTP values for current health in 165 outpatients with cerebral aneurysms. We assessed cognitive impairment with the Mini Mental State Examination (MMSE; scores Results Eleven patients (7% had MMSE scores Conclusion Cognitive impairment is associated with lower preferences for current health in patients with cerebral aneurysms. Cognitively impaired patients have poor inter-preference test correlations and different response distributions compared to unimpaired patients.

  7. Sensory processing, neurocognition, and social cognition in schizophrenia: Towards a cohesive cognitive model

    NARCIS (Netherlands)

    Jong, J.S. de; Gelder, B.B. de; Hodiamont, P.P.G.

    2013-01-01

    Schizophrenia research has identified deficits in neurocognition, social cognition, and sensory processing. Because a cohesive model of "disturbed cognitive machinery" is currently lacking, we built a conceptual model to integrate neurocognition, social cognition, and sensory processing. In a cross-

  8. When to Use Cognitive Modeling.

    Science.gov (United States)

    Harmon, Paul; Evans, Kay

    1984-01-01

    Cognitive modeling works best when teaching overt, observable activities. The basic structure of a good cognitive program includes modeling, case study exercises, social reinforcement, and transfer of training. (JB)

  9. Physical models of cognition

    Science.gov (United States)

    Zak, Michail

    1994-05-01

    This paper presents and discusses physical models for simulating some aspects of neural intelligence, and, in particular, the process of cognition. The main departure from the classical approach here is in utilization of a terminal version of classical dynamics introduced by the author earlier. Based upon violations of the Lipschitz condition at equilibrium points, terminal dynamics attains two new fundamental properties: it is spontaneous and nondeterministic. Special attention is focused on terminal neurodynamics as a particular architecture of terminal dynamics which is suitable for modeling of information flows. Terminal neurodynamics possesses a well-organized probabilistic structure which can be analytically predicted, prescribed, and controlled, and therefore which presents a powerful tool for modeling real-life uncertainties. Two basic phenomena associated with random behavior of neurodynamic solutions are exploited. The first one is a stochastic attractor—a stable stationary stochastic process to which random solutions of a closed system converge. As a model of the cognition process, a stochastic attractor can be viewed as a universal tool for generalization and formation of classes of patterns. The concept of stochastic attractor is applied to model a collective brain paradigm explaining coordination between simple units of intelligence which perform a collective task without direct exchange of information. The second fundamental phenomenon discussed is terminal chaos which occurs in open systems. Applications of terminal chaos to information fusion as well as to explanation and modeling of coordination among neurons in biological systems are discussed. It should be emphasized that all the models of terminal neurodynamics are implementable in analog devices, which means that all the cognition processes discussed in the paper are reducible to the laws of Newtonian mechanics.

  10. Current Cognitive Approaches to Childhood Psychopathology.

    Science.gov (United States)

    Garfield, Sol L., Ed.

    1984-01-01

    Presents six developmentally oriented articles on childhood psychopathology. Reviews research dealing with autism, social isolation, interpersonal understanding, sociomoral reasoning, cognitive controls, and aggression and includes an overview of progress and problems in the cognitive approach to clinical child psychology. (JAC)

  11. Inner rehearsal modeling for cognitive robotics

    Science.gov (United States)

    Braun, Jerome J.; Bergen, Karianne; Dasey, Timothy J.

    2011-05-01

    This paper presents a biomimetic approach involving cognitive process modeling, for use in intelligent robot decisionmaking. The principle of inner rehearsal, a process believed to occur in human and animal cognition, involves internal rehearsing of actions prior to deciding on and executing an overt action, such as a motor action. The inner-rehearsal algorithmic approach we developed is posed and investigated in the context of a relatively complex cognitive task, an under-rubble search and rescue. The paper presents the approach developed, a synthetic environment which was also developed to enable its studies, and the results to date. The work reported here is part of a Cognitive Robotics effort in which we are currently engaged, focused on exploring techniques inspired by cognitive science and neuroscience insights, towards artificial cognition for robotics and autonomous systems.

  12. Time models and cognitive processes: a review

    Directory of Open Access Journals (Sweden)

    Michail eManiadakis

    2014-02-01

    Full Text Available The sense of time is an essential capacity of humans, with a major role in many of the cognitive processes expressed in our daily lifes. So far, in cognitive science and robotics research, mental capacities have been investigated in a theoretical and modelling framework that largely neglects the flow of time. Only recently there has been a small but constantly increasing interest in the temporal aspects of cognition, integrating time into a range of different models of perceptuo-motor capacities. The current paper aims to review existing works in the field and suggest directions for fruitful future work. This is particularly important for the newly developed field of artificial temporal cognition that is expected to significantly contribute in the development of sophisticated artificial agents seamlessly integrated into human societies.

  13. Syncing your brain: electric currents to enhance cognition

    NARCIS (Netherlands)

    Schutter, D.J.L.G.

    2014-01-01

    Contemporary studies in cognitive neuroscience demonstrate that cognitive performance can be enhanced by applying exogenous low-intensity electric currents to the brain. These findings have resulted in a widespread interest from both scientists and popular media, particularly, regarding the host of

  14. Syncing your brain: electric currents to enhance cognition

    NARCIS (Netherlands)

    Schutter, D.J.L.G.

    2014-01-01

    Contemporary studies in cognitive neuroscience demonstrate that cognitive performance can be enhanced by applying exogenous low-intensity electric currents to the brain. These findings have resulted in a widespread interest from both scientists and popular media, particularly, regarding the host of

  15. Models of current sintering

    Science.gov (United States)

    Angst, Sebastian; Engelke, Lukas; Winterer, Markus; Wolf, Dietrich E.

    2017-06-01

    Densification of (semi-)conducting particle agglomerates with the help of an electrical current is much faster and more energy efficient than traditional thermal sintering or powder compression. Therefore, this method becomes more and more common among experimentalists, engineers, and in industry. The mechanisms at work at the particle scale are highly complex because of the mutual feedback between current and pore structure. This paper extends previous modelling approaches in order to study mixtures of particles of two different materials. In addition to the delivery of Joule heat throughout the sample, especially in current bottlenecks, thermoelectric effects must be taken into account. They lead to segregation or spatial correlations in the particle arrangement. Various model extensions are possible and will be discussed.

  16. Experimental pain processing in individuals with cognitive impairment: current state of the science

    DEFF Research Database (Denmark)

    Defrin, R; Amanzio, Martina; de Tomasso, M

    2015-01-01

    to cognitively unimpaired individuals. Our current understanding of the neurobiological mechanisms underpinning these alterations is limited, but may be enhanced through the use of animal models of CI which also exhibit alterations in nociceptive responding. Further research employing additional behavioural...

  17. Formal modelling of cognitive interpretation

    OpenAIRE

    Rukšenas, R.; Curzon, P; Back, J.; Blandford, A.

    2007-01-01

    We formally specify the interpretation stage in a dual state space human-computer interaction cycle. This is done by extending/reorganising our previous cognitive architecture. In particular, we focus on shape related aspects of the interpretation process associated with device input prompts. A cash-point example illustrates our approach. Using the SAL model checking environment, we show how the extended cognitive architecture facilitates detection of prompt-shape induced human error. © Sprin...

  18. Cognitive Diagnostic Modeling Using R

    Science.gov (United States)

    Ravand, Hamdollah

    2015-01-01

    Cognitive diagnostic models (CDM) have been around for more than a decade but their application is far from widespread for mainly two reasons: (1) CDMs are novel, as compared to traditional IRT models. Consequently, many researchers lack familiarity with them and their properties, and (2) Software programs doing CDMs have been expensive and not…

  19. Cognitive Remediation in Schizophrenia: Current Status and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Stefano Barlati

    2013-01-01

    Full Text Available Objectives. This study is aimed to review the current scientific literature on cognitive remediation in schizophrenia. In particular, the main structured protocols of cognitive remediation developed for schizophrenia are presented and the main results reported in recent meta-analyses are summarized. Possible benefits of cognitive remediation in the early course of schizophrenia and in subjects at risk for psychosis are also discussed. Methods. Electronic search of the relevant studies which appeared in the PubMed database until April 2013 has been performed and all the meta-analyses and review articles on cognitive remediation in schizophrenia have been also taken into account. Results. Numerous intervention programs have been designed, applied, and evaluated, with the objective of improving cognition and social functioning in schizophrenia. Several quantitative reviews have established that cognitive remediation is effective in reducing cognitive deficits and in improving functional outcome of the disorder. Furthermore, the studies available support the usefulness of cognitive remediation when applied in the early course of schizophrenia and even in subjects at risk of the disease. Conclusions. Cognitive remediation is a promising approach to improve real-world functioning in schizophrenia and should be considered a key strategy for early intervention in the psychoses.

  20. Assessing and treating cognitive impairment in schizophrenia: current and future.

    Science.gov (United States)

    Lin, Chun-Yuan; Tsai, Guochuan E; Lane, Hsien-Yuan

    2014-01-01

    Schizophrenia is a serious neuropsychiatric disease characterized by positive symptoms, negative symptoms and cognitive impairment. Evidence have shown that cognitive impairment sustains in every clinical stage, may relate with the liability, may predict functional outcome in schizophrenia and could be the core symptom of schizophrenia. The treatment of cognitive impairment in schizophrenia could alleviate the burden of the illness and has become the subject of intensive research. In this review, we synthesize current advances of assessing strategies, pharmacological and non-pharmacological treatments of cognitive impairment in schizophrenia. According to the registered records of ClinicalTrials.gov, the most widely studied strategies have aimed at modifying neurochemical mechanisms of dopamine metabolism, glutamate metabolism, γ-aminobutyric acid (GABA) metabolism, serotonin metabolism, acetylcholine metabolism, and oxytocin. Despite preclinical data for putative pro-cognitive drugs, their clinical benefits for schizophrenia patients have been limited. The small sample sizes and the short treatment duration could be related with the suboptimal results. Evidence supported the short-term benefits of cognitive remediation therapy on cognitive domains with small to moderate effects; however, the small sample sizes and the characteristics of subjects limited the generalization of the positive results and the long-term functional outcome is not clear. Combination therapy is promising, by integrating pro-cognitive agents and cognitive rehabilitation programs or combining two kinds of pro-cognitive agents via different mechanisms. Future studies should investigate the pro-cognitive drugs' long-term efficacy, rebound deterioration in psychosis/cognition following discontinuation, and related biomarkers of functional outcome.

  1. Gender Recognition Using Cognitive Modeling

    DEFF Research Database (Denmark)

    Fagertun, Jens; Andersen, Tobias; Paulsen, Rasmus Reinhold

    2012-01-01

    In this work, we use cognitive modeling to estimate the ”gender strength” of frontal faces, a continuous class variable, superseding the traditional binary class labeling. To incorporate this continuous variable we suggest a novel linear gender classification algorithm, the Gender Strength Regres...

  2. Cognitive Behavioral Therapy in Social Anxiety Disorder: Current Concepts

    Directory of Open Access Journals (Sweden)

    Nurhan Fistikci

    2015-09-01

    Full Text Available Cognitive behavioral therapy is still one of the most important treatment modalities in social anxiety disorder with a high level of evidence. However, some patients do not fully benefit from these therapies and this fact leads to ongoing search for new approaches. This paper reviews use of cognitive behavioral therapy in social anxiety disorder studies and discusses related updated concepts. The frequent use of computer-assisted therapy for most of recent studies was found noteworthy. Recent studies regarding social anxiety disorder focused on concepts such as attention bias, biased information processing, attention training, judgment biases, internet-based cognitive behavioral therapies and social mishap exposure. Internet-based cognitive-behavioral therapy seemed to be a good option for people who were unable to access face to face treatment. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2015; 7(3.000: 229-243

  3. Bayesian modeling of flexible cognitive control

    Science.gov (United States)

    Jiang, Jiefeng; Heller, Katherine; Egner, Tobias

    2014-01-01

    Cognitive control” describes endogenous guidance of behavior in situations where routine stimulus-response associations are suboptimal for achieving a desired goal. The computational and neural mechanisms underlying this capacity remain poorly understood. We examine recent advances stemming from the application of a Bayesian learner perspective that provides optimal prediction for control processes. In reviewing the application of Bayesian models to cognitive control, we note that an important limitation in current models is a lack of a plausible mechanism for the flexible adjustment of control over conflict levels changing at varying temporal scales. We then show that flexible cognitive control can be achieved by a Bayesian model with a volatility-driven learning mechanism that modulates dynamically the relative dependence on recent and remote experiences in its prediction of future control demand. We conclude that the emergent Bayesian perspective on computational mechanisms of cognitive control holds considerable promise, especially if future studies can identify neural substrates of the variables encoded by these models, and determine the nature (Bayesian or otherwise) of their neural implementation. PMID:24929218

  4. Bayesian modeling of flexible cognitive control.

    Science.gov (United States)

    Jiang, Jiefeng; Heller, Katherine; Egner, Tobias

    2014-10-01

    "Cognitive control" describes endogenous guidance of behavior in situations where routine stimulus-response associations are suboptimal for achieving a desired goal. The computational and neural mechanisms underlying this capacity remain poorly understood. We examine recent advances stemming from the application of a Bayesian learner perspective that provides optimal prediction for control processes. In reviewing the application of Bayesian models to cognitive control, we note that an important limitation in current models is a lack of a plausible mechanism for the flexible adjustment of control over conflict levels changing at varying temporal scales. We then show that flexible cognitive control can be achieved by a Bayesian model with a volatility-driven learning mechanism that modulates dynamically the relative dependence on recent and remote experiences in its prediction of future control demand. We conclude that the emergent Bayesian perspective on computational mechanisms of cognitive control holds considerable promise, especially if future studies can identify neural substrates of the variables encoded by these models, and determine the nature (Bayesian or otherwise) of their neural implementation.

  5. Current advances in the cognitive neuroscience of music.

    Science.gov (United States)

    Levitin, Daniel J; Tirovolas, Anna K

    2009-03-01

    The study of music perception and cognition is one of the oldest topics in experimental psychology. The last 20 years have seen an increased interest in understanding the functional neuroanatomy of music processing in humans, using a variety of technologies including fMRI, PET, ERP, MEG, and lesion studies. We review current findings in the context of a rich intellectual history of research, organized by the cognitive systems underlying different aspects of human musical behavior. We pay special attention to the perception of components of musical processing, musical structure, laterality effects, cultural issues, links between music and movement, emotional processing, expertise, and the amusias. Current trends are noted, such as the increased interest in evolutionary origins of music and comparisons of music and language. The review serves to demonstrate the important role that music can play in informing broad theories of higher order cognitive processes such as music in humans.

  6. Network Models for Cognitive Development and Intelligence

    National Research Council Canada - National Science Library

    Han L J VanDer; Kees-Jan Kan; Maarten Marsman; Claire E Stevenson

    2017-01-01

    ... (dimensionality of individual differences). The welcome integration of the two fields requires the construction of mechanistic models of cognition and cognitive development that explain key phenomena in individual differences research...

  7. Cognitive Modeling of Social Behaviors

    Science.gov (United States)

    Clancey, William J.; Sierhuis, Maarten; Damer. Bruce; Brodsky, Boris

    2004-01-01

    The driving theme of cognitive modeling for many decades has been that knowledge affects how and which goals are accomplished by an intelligent being (Newell 1991). But when one examines groups of people living and working together, one is forced to recognize that whose knowledge is called into play, at a particular time and location, directly affects what the group accomplishes. Indeed, constraints on participation, including roles, procedures, and norms, affect whether an individual is able to act at all (Lave & Wenger 1991; Jordan 1992; Scribner & Sachs 1991). To understand both individual cognition and collective activity, perhaps the greatest opportunity today is to integrate the cognitive modeling approach (which stresses how beliefs are formed and drive behavior) with social studies (which stress how relationships and informal practices drive behavior). The crucial insight is that norms are conceptualized in the individual &nd as ways of carrying out activities (Clancey 1997a, 2002b). This requires for the psychologist a shift from only modeling goals and tasks - why people do what they do - to modeling behavioral patterns-what people do-as they are engaged in purposeful activities. Instead of a model that exclusively deduces actions from goals, behaviors are also, if not primarily, driven by broader patterns of chronological and located activities (akin to scripts). This analysis is particular inspired by activity theory (Leont ev 1979). While acknowledging that knowledge (relating goals and operations) is fundamental for intelligent behavior, activity theory claims that a broader driver is the person s motives and conceptualization of activities. Such understanding of human interaction is normative (i.e., viewed with respect to social standards), affecting how knowledge is called into play and applied in practice. Put another way, how problems are discovered and framed, what methods are chosen, and indeed who even cares or has the authority to act, are all

  8. Assessing the Current State of Cognitive Frailty: Measurement Properties.

    Science.gov (United States)

    Sargent, L; Brown, R

    2017-01-01

    Currently, an estimated 25-30% of people ages 85 or older have dementia, with a projected 115 million people worldwide living with dementia by 2050. With this worldwide phenomenon fast approaching, early detection of at-risk older adults and development of interventions focused on preventing loss in quality of life are increasingly important. A new construct defined by the International Consensus Group (I.A.N.A/I.A.G.G) as «cognitive frailty» combines domains of physical frailty with cognitive impairment and provides a framework for research that may provide a means to identify individuals with cognitive impairment caused by nonneurodegenerative conditions. Using the integrative review method of Whittemore and Knafl., 2005 this study examines and appraises the optimal measures for detecting cognitive frailty in clinical populations of older adults. The integrative review was conducted using PubMed, CINAHL, Web of Science, PsycInfo, and ProQuest Dissertations and Theses. From the total 185 articles retrieved, review of titles and key words were conducted. Following the initial review, 168 articles did not meet the inclusion criteria for association of frailty and cognition. Of the 18 fulltext articles reviewed, 11 articles met the inclusion criteria; these articles were reviewed in-depth to determine validity and reliability of the cognitive frailty measures. Predictive validity was established by the studies reviewed in four main areas: frailty and type of dementia MCI (OR 7.4, 95% CI 4.2-13.2), vascular dementia (OR 6.7, 95% CI 1.6-27.4) and Alzheimer's dementia (OR 3.2, 95% CI 1.7-6.2), frailty and vascular dementia (VaAD) is further supported by the rate of change in frailty x macroinfarcts (r = 0.032, p < 0.001); frailty and the individual domains of cognitive function established with the relationship of neurocognitive speed and change in cognition using regression coefficients; individual components of frailty and individual domains of cognitive function

  9. The cognitive life of mechanical molecular models.

    Science.gov (United States)

    Charbonneau, Mathieu

    2013-12-01

    The use of physical models of molecular structures as research tools has been central to the development of biochemistry and molecular biology. Intriguingly, it has received little attention from scholars of science. In this paper, I argue that these physical models are not mere three-dimensional representations but that they are in fact very special research tools: they are cognitive augmentations. Despite the fact that they are external props, these models serve as cognitive tools that augment and extend the modeler's cognitive capacities and performance in molecular modeling tasks. This cognitive enhancement is obtained because of the way the modeler interacts with these models, the models' materiality contributing to the solving of the molecule's structure. Furthermore, I argue that these material models and their component parts were designed, built and used specifically to serve as cognitive facilitators and cognitive augmentations.

  10. Compulsive buying: a cognitive-behavioural model.

    Science.gov (United States)

    Kellett, Stephen; Bolton, Jessica V

    2009-01-01

    Compulsive buying (CB) has only relatively recently become a topic of interest for researchers and clinicians alike. This hiatus means that (unlike other impulse control disorders) there is currently little theoretical guidance for clinicians attempting to intervene with CB clients and no established model for researchers to evaluate, distil and refine. The current paper summarizes and organizes the main extant identified factors in the CB literature into four distinct phases: (1) antecedents; (2) internal/external triggers; (3) the act of buying; and finally, (4) post-purchase. The relationships and interactions between the identified phases are then hypothesized, within the proposed cognitive-behavioural model. The model distinguishes the key cognitive, affective and behavioural factors within each phase and identifies how CB can become self-reinforcing over time. The over-arching treatment implication is that CB can be re-conceptualized as chronic and repetitive failure in self-regulation efforts, and that psychological interventions can accommodate this in attempting to facilitate change. A successful case example is provided of a 'co-dependent compulsive buyer' using the model, with psychometric evaluation of key aspects of CB and mental health at assessment, termination and 6-month follow-up. The research and clinical implications of the proposed model are discussed, alongside identified short-comings and the need for psychological services to respond appropriately to CB clients seeking help.

  11. Using of Structural Equation Modeling Techniques in Cognitive Levels Validation

    Directory of Open Access Journals (Sweden)

    Natalija Curkovic

    2012-10-01

    Full Text Available When constructing knowledge tests, cognitive level is usually one of the dimensions comprising the test specifications with each item assigned to measure a particular level. Recently used taxonomies of the cognitive levels most often represent some modification of the original Bloom’s taxonomy. There are many concerns in current literature about existence of predefined cognitive levels. The aim of this article is to investigate can structural equation modeling techniques confirm existence of different cognitive levels. For the purpose of the research, a Croatian final high-school Mathematics exam was used (N = 9626. Confirmatory factor analysis and structural regression modeling were used to test three different models. Structural equation modeling techniques did not support existence of different cognitive levels in this case. There is more than one possible explanation for that finding. Some other techniques that take into account nonlinear behaviour of the items as well as qualitative techniques might be more useful for the purpose of the cognitive levels validation. Furthermore, it seems that cognitive levels were not efficient descriptors of the items and so improvements are needed in describing the cognitive skills measured by items.

  12. The place of modeling in cognitive science.

    Science.gov (United States)

    McClelland, James L

    2009-01-01

    I consider the role of cognitive modeling in cognitive science. Modeling, and the computers that enable it, are central to the field, but the role of modeling is often misunderstood. Models are not intended to capture fully the processes they attempt to elucidate. Rather, they are explorations of ideas about the nature of cognitive processes. In these explorations, simplification is essential-through simplification, the implications of the central ideas become more transparent. This is not to say that simplification has no downsides; it does, and these are discussed. I then consider several contemporary frameworks for cognitive modeling, stressing the idea that each framework is useful in its own particular ways. Increases in computer power (by a factor of about 4 million) since 1958 have enabled new modeling paradigms to emerge, but these also depend on new ways of thinking. Will new paradigms emerge again with the next 1,000-fold increase?

  13. Association between current smoking and cognitive impairment depends on age: A cross-sectional study in Xi'an, China.

    Science.gov (United States)

    Liu, Jie; Shang, Suhang; Li, Pei; Deng, Meiying; Chen, Chen; Jiang, Yu; Dang, Liangjun; Qu, Qiumin

    2017-09-08

    Cigarette smoking is a modifiable risk factor for cognitive impairment, while the relationship between current smoking and cognitive impairment is not fully understood. The objectives were to identify a possible association between current smoking and cognitive impairment depending on age in the Chinese rural population. Data for the study consisted of 1,782 participants (40 years and older) who lived in a rural village in the vicinity of Xi'an, China. Data about smoking history and cognitive function were collected. Cognitive function was scored by the Mini-Mental State Examination. The effect of age on the relationship between current smoking and cognitive impairment was analyzed with interaction and stratified analysis by logistic regression models. Interaction analysis showed that current smoking is positively related with cognitive impairment (odds ratio [OR]=9.067; 95% confidence interval [95% CI] 1.305-62.979; P=.026). However, the interaction term, age by current smoking, is negatively related with cognitive impairment (OR=0.969; 95%CI 0.939-0.999; P=.045). Stratified logistic regression showed that in the 40-65 years of age sublayer, OR of current smoking is 1.966 (P=.044), whereas in the>65 years of age sublayer, the OR is 0.470 (P=.130). This means that the association between current smoking and cognitive impairment with age might be positive (OR>1) in lower age sublayers, but no significant difference in higher age sublayers. In conclusion, current smoking might be positively associated with cognitive impairment in the middle-aged but the relationship declines with increasing age. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  14. Using cognitive modeling for requirements engineering in anesthesiology

    NARCIS (Netherlands)

    Pott, C; le Feber, J

    2005-01-01

    Cognitive modeling is a complexity reducing method to describe significant cognitive processes under a specified research focus. Here, a cognitive process model for decision making in anesthesiology is presented and applied in requirements engineering. Three decision making situations of

  15. Modeling cognitive dysfunction in neurofibromatosis-1.

    Science.gov (United States)

    Diggs-Andrews, Kelly A; Gutmann, David H

    2013-04-01

    Cognitive dysfunction, including significant impairments in learning, behavior, and attention, is found in over 10% of children in the general population. However, in the common inherited cancer predisposition syndrome, neurofibromatosis type 1 (NF1), the prevalence of these cognitive deficits approaches 70%. As a monogenic disorder, NF1 provides a unique genetic tool to identify and dissect mechanistically the molecular and cellular bases underlying cognitive dysfunction. In this review, we discuss Nf1 fly and mouse systems that mimic many of the cognitive abnormalities seen in children with NF1. Further, we describe discoveries from these models that have uncovered defects in the regulation of Ras activity, cAMP generation, and dopamine homeostasis as key mechanisms important for cognitive dysfunction in children with NF1.

  16. Cognitive Virtualization: Combining Cognitive Models and Virtual Environments

    Energy Technology Data Exchange (ETDEWEB)

    Tuan Q. Tran; David I. Gertman; Donald D. Dudenhoeffer; Ronald L. Boring; Alan R. Mecham

    2007-08-01

    3D manikins are often used in visualizations to model human activity in complex settings. Manikins assist in developing understanding of human actions, movements and routines in a variety of different environments representing new conceptual designs. One such environment is a nuclear power plant control room, here they have the potential to be used to simulate more precise ergonomic assessments of human work stations. Next generation control rooms will pose numerous challenges for system designers. The manikin modeling approach by itself, however, may be insufficient for dealing with the desired technical advancements and challenges of next generation automated systems. Uncertainty regarding effective staffing levels; and the potential for negative human performance consequences in the presence of advanced automated systems (e.g., reduced vigilance, poor situation awareness, mistrust or blind faith in automation, higher information load and increased complexity) call for further research. Baseline assessment of novel control room equipment(s) and configurations needs to be conducted. These design uncertainties can be reduced through complementary analysis that merges ergonomic manikin models with models of higher cognitive functions, such as attention, memory, decision-making, and problem-solving. This paper will discuss recent advancements in merging a theoretical-driven cognitive modeling framework within a 3D visualization modeling tool to evaluate of next generation control room human factors and ergonomic assessment. Though this discussion primary focuses on control room design, the application for such a merger between 3D visualization and cognitive modeling can be extended to various areas of focus such as training and scenario planning.

  17. Perspectives on modeling in cognitive science.

    Science.gov (United States)

    Shiffrin, Richard M

    2010-10-01

    This commentary gives a personal perspective on modeling and modeling developments in cognitive science, starting in the 1950s, but focusing on the author's personal views of modeling since training in the late 1960s, and particularly focusing on advances since the official founding of the Cognitive Science Society. The range and variety of modeling approaches in use today are remarkable, and for many, bewildering. Yet to come to anything approaching adequate insights into the infinitely complex fields of mind, brain, and intelligent systems, an extremely wide array of modeling approaches is vital and necessary.

  18. Effects of Transcranial Alternating Current Stimulation on Cognitive Functions in Healthy Young and Older Adults

    Directory of Open Access Journals (Sweden)

    Daria Antonenko

    2016-01-01

    Full Text Available Recently, transcranial alternating current stimulation (tACS has emerged as a tool to enhance human cognitive processes. Here, we provide a brief summary of the rationale behind tACS-induced effects on task-relevant brain oscillations and associated cognitive functions and review previous studies in young subjects that have applied tACS in cognitive paradigms. Additionally, we present pilot data where we administered theta-tACS (6 Hz over the temporoparietal cortex and a supraorbital reference for 20 min during implicit language learning in healthy young (mean/SD age: 22/2 and older (mean/SD age: 66/4 adults, in a sham-controlled crossover design. Linear mixed models revealed significantly increased retrieval accuracy following tACS-accompanied associative learning, after controlling for session order and learning success. These data provide the first implementation of tACS during cognitive performance in older adults and support recent studies suggesting that tACS in the theta frequency range may serve as a tool to enhance cognition, possibly through direct modulation of task-relevant brain oscillations. So far, studies have been heterogeneous in their designs, leaving a number of issues to be addressed in future research, including the setup of electrodes and optimal stimulation frequencies to be employed, as well as the interaction with age and underlying brain pathologies in specific patient populations.

  19. Physical exercise and cognitive performance in the elderly: current perspectives.

    Science.gov (United States)

    Kirk-Sanchez, Neva J; McGough, Ellen L

    2014-01-01

    In an aging population with increasing incidence of dementia and cognitive impairment, strategies are needed to slow age-related decline and reduce disease-related cognitive impairment in older adults. Physical exercise that targets modifiable risk factors and neuroprotective mechanisms may reduce declines in cognitive performance attributed to the normal aging process and protect against changes related to neurodegenerative diseases such as Alzheimer's disease and other types of dementia. In this review we summarize the role of exercise in neuroprotection and cognitive performance, and provide information related to implementation of physical exercise programs for older adults. Evidence from both animal and human studies supports the role of physical exercise in modifying metabolic, structural, and functional dimensions of the brain and preserving cognitive performance in older adults. The results of observational studies support a dose-dependent neuroprotective relationship between physical exercise and cognitive performance in older adults. Although some clinical trials of exercise interventions demonstrate positive effects of exercise on cognitive performance, other trials show minimal to no effect. Although further research is needed, physical exercise interventions aimed at improving brain health through neuroprotective mechanisms show promise for preserving cognitive performance. Exercise programs that are structured, individualized, higher intensity, longer duration, and multicomponent show promise for preserving cognitive performance in older adults.

  20. Cognition and depression: current status and future directions.

    Science.gov (United States)

    Gotlib, Ian H; Joormann, Jutta

    2010-01-01

    Cognitive theories of depression posit that people's thoughts, inferences, attitudes, and interpretations, and the way in which they attend to and recall information, can increase their risk for depression. Three mechanisms have been implicated in the relation between biased cognitive processing and the dysregulation of emotion in depression: inhibitory processes and deficits in working memory, ruminative responses to negative mood states and negative life events, and the inability to use positive and rewarding stimuli to regulate negative mood. In this review, we present a contemporary characterization of depressive cognition and discuss how different cognitive processes are related not only to each other, but also to emotion dysregulation, the hallmark feature of depression. We conclude that depression is characterized by increased elaboration of negative information, by difficulties disengaging from negative material, and by deficits in cognitive control when processing negative information. We discuss treatment implications of these conclusions and argue that the study of cognitive aspects of depression must be broadened by investigating neural and genetic factors that are related to cognitive dysfunction in this disorder. Such integrative investigations should help us gain a more comprehensive understanding of how cognitive and biological factors interact to affect the onset, maintenance, and course of depression.

  1. Cognitive Rehabilitation for Executive Dysfunction in Parkinson's Disease: Application and Current Directions

    Directory of Open Access Journals (Sweden)

    Jessica Calleo

    2012-01-01

    Full Text Available Cognitive dysfunction in Parkinson's disease contributes to disability, caregiver strain, and diminished quality of life. Cognitive rehabilitation, a behavioral approach to improve cognitive skills, has potential as a treatment option to improve and maintain cognitive skills and increase quality of life for those with Parkinson's disease-related cognitive dysfunction. Four cognitive rehabilitation programs in individuals with PD are identified from the literature. Characteristics of the programs and outcomes are reviewed and critiqued. Current studies on cognitive rehabilitation in PD demonstrate feasibility and acceptability of a cognitive rehabilitation program for patients with PD, but are limited by their small sample size and data regarding generalization of effects over the long term. Because PD involves progressive heterogeneous physical, neurological, and affective difficulties, future cognitive rehabilitation programs should aim for flexibility and individualization, according to each patient's strengths and deficits.

  2. Physical exercise and cognitive performance in the elderly: current perspectives

    Directory of Open Access Journals (Sweden)

    Kirk-Sanchez NJ

    2013-12-01

    Full Text Available Neva J Kirk-Sanchez,1 Ellen L McGough21Department of Physical Therapy, University of Miami Miller School of Medicine, Miami, FL, USA; 2Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USAAbstract: In an aging population with increasing incidence of dementia and cognitive impairment, strategies are needed to slow age-related decline and reduce disease-related cognitive impairment in older adults. Physical exercise that targets modifiable risk factors and neuroprotective mechanisms may reduce declines in cognitive performance attributed to the normal aging process and protect against changes related to neurodegenerative diseases such as Alzheimer's disease and other types of dementia. In this review we summarize the role of exercise in neuroprotection and cognitive performance, and provide information related to implementation of physical exercise programs for older adults. Evidence from both animal and human studies supports the role of physical exercise in modifying metabolic, structural, and functional dimensions of the brain and preserving cognitive performance in older adults. The results of observational studies support a dose-dependent neuroprotective relationship between physical exercise and cognitive performance in older adults. Although some clinical trials of exercise interventions demonstrate positive effects of exercise on cognitive performance, other trials show minimal to no effect. Although further research is needed, physical exercise interventions aimed at improving brain health through neuroprotective mechanisms show promise for preserving cognitive performance. Exercise programs that are structured, individualized, higher intensity, longer duration, and multicomponent show promise for preserving cognitive performance in older adults.Keywords: aging, neurodegeneration, dementia, brain, physical activity

  3. August Knoblauch and amusia: a nineteenth-century cognitive model of music.

    Science.gov (United States)

    Johnson, Julene K; Graziano, Amy B

    2003-02-01

    Early models of human cognition can be traced to nineteenth-century investigations of brain and behavior. Influential neurologists such as Wernicke, Kussmaul, and Lichtheim constructed diagrammatic models to illustrate current theories of cognition. Language was the most commonly studied cognitive function during this time; however, investigators also studied other cognitive functions, such as music and visual processing. While a number of nineteenth-century neurologists made observations about music abilities in aphasic patients, August Knoblauch, a German physician and anatomist, was the first to propose a diagrammatic model of music (1888/1890). He described a detailed cognitive model of music processing, hypothesized the existence of nine disorders of music production and perception, and coined the term "amusia." Knoblauch's model is the earliest cognitive model of music and is largely unrecognized as an important part of the history of neurology, neuropsychology, and music cognition. Copyright 2003 Elsevier Science (USA)

  4. Hierarchical Item Response Models for Cognitive Diagnosis

    Science.gov (United States)

    Hansen, Mark Patrick

    2013-01-01

    Cognitive diagnosis models (see, e.g., Rupp, Templin, & Henson, 2010) have received increasing attention within educational and psychological measurement. The popularity of these models may be largely due to their perceived ability to provide useful information concerning both examinees (classifying them according to their attribute profiles)…

  5. Corvid Caching : Insights From a Cognitive Model

    NARCIS (Netherlands)

    van der Vaart, Elske; Verbrugge, Rineke; Hemelrijk, Charlotte K.

    2011-01-01

    Caching and recovery of food by corvids is well-studied, but some ambiguous results remain. To help clarify these, we built a computational cognitive model. It is inspired by similar models built for humans, and it assumes that memory strength depends on frequency and recency of use. We compared our

  6. Current Cognitive Distortion Theory and Research: An Internalist Approach to Cognition

    Science.gov (United States)

    Gannon, Theresa A.

    2009-01-01

    This review examines contemporary cognitive distortion theory and research relating to sexual offenders. In particular, this review highlights that researchers--to date--have tended to adopt an internalist approach to sexual offenders' cognition which views offence-supportive cognitive activity as occurring solely within the mind. This review…

  7. Current Cognitive Distortion Theory and Research: An Internalist Approach to Cognition

    Science.gov (United States)

    Gannon, Theresa A.

    2009-01-01

    This review examines contemporary cognitive distortion theory and research relating to sexual offenders. In particular, this review highlights that researchers--to date--have tended to adopt an internalist approach to sexual offenders' cognition which views offence-supportive cognitive activity as occurring solely within the mind. This review…

  8. Cognitive engineering models in space systems

    Science.gov (United States)

    Mitchell, Christine M.

    1993-01-01

    NASA space systems, including mission operations on the ground and in space, are complex, dynamic, predominantly automated systems in which the human operator is a supervisory controller. Models of cognitive functions in complex systems are needed to describe human performance and form the theoretical basis of operator workstation design, including displays, controls, and decision aids. Currently, there several candidate modeling methodologies. They include the Rasmussen abstraction/aggregation hierarchy and decision ladder, the goal-means network, the problem behavior graph, and the operator function model. The research conducted under the sponsorship of this grant focuses on the extension of the theoretical structure of the operator function model and its application to NASA Johnson mission operations and space station applications. The initial portion of this research consists of two parts. The first is a series of technical exchanges between NASA Johnson and Georgia Tech researchers. The purpose is to identify candidate applications for the current operator function model; prospects include mission operations and the Data Management System Testbed. The second portion will address extensions of the operator function model to tailor it to the specific needs of Johnson applications. At this point, we have accomplished two things. During a series of conversations with JSC researchers, we have defined the technical goal of the research supported by this grant to be the structural definition of the operator function model and its computer implementation, OFMspert. Both the OFM and OFMspert have matured to the point that they require infrastructure to facilitate use by researchers not involved in the evolution of the tools. The second accomplishment this year was the identification of the Payload Deployment and Retrieval System (PDRS) as a candidate system for the case study. In conjunction with government and contractor personnel in the Human-Computer Interaction Lab

  9. [Cognitive neuroscience of aging: explanatory models].

    Science.gov (United States)

    Grandi, Fabrissio; Tirapu Ustárroz, Javier

    2017-05-12

    The aim of the cognitive neuroscience of aging is the study of brain activity and the cognitive processes associated with age. In order to understand the dynamics of neurocognitive activity in older people, the present review highlights four explanatory models. The first one (HAROLD) highlights brain bilaterality, mainly in the pre-frontal cortex. The second paradigm (PASA) places special emphasis on neuronal polarisation (anterior-posterior). The third model (CRUNCH) relates the manifest activity of the brain to the level of complexity of the task. The last one (ELSA) emphasises the spatial and temporal distribution of brain activity in the different phases of recovery. Although different in their content, the four explanatory models are perfectly compatible with the findings reported by neuroimaging techniques, suggesting the use of compensation strategies and cognitive reserve for interventions that may help to optimise the performance of older people. Copyright © 2017 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Cognitive enrichment and welfare: Current approaches and future directions

    Directory of Open Access Journals (Sweden)

    Fay E. Clark

    2017-02-01

    Full Text Available “Cognitive enrichment” is a subset of enrichment that has gained interest from researchers over the past decade, particularly those working in zoos. This review explores the forms of cognitive enrichment that have been attempted for laboratory, farmed and zoo animals with a focus on the latter, including various definitions, aims, and approaches. This review reveals the fundamental theoretical and practical problems associated with cognitive enrichment, leading to recommendations for further research in this field. Critically, more research is needed to elucidate what makes challenges appropriate for certain taxa, acknowledging that individual differences exist. Going forward, we should be prepared to incorporate more computer technology into cognitive tasks, and examine novel welfare indicators such as flow, competence, and agency.

  11. Current evidence on dietary pattern and cognitive function.

    Science.gov (United States)

    Cheung, Bernice H K; Ho, Ivan C H; Chan, Ruth S M; Sea, Mandy M M; Woo, Jean

    2014-01-01

    With global aging population, age-related cognitive decline becomes epidemic. Lifestyle-related factor is one of the key preventative measures. Dietary pattern analysis which considers dietary complexity has recently used to examine the linkage between nutrition and cognitive function. A priori approach defines dietary pattern based on existing knowledge. Results of several dietary pattern scores were summarized. The heterogeneity of assessment methods and outcome measurements lead to inconsistent results. Posteriori approach derives a dietary pattern independently of the existing nutrition-disease knowledge. It showed a dietary pattern abundant with plant-based food, oily fish, lower consumption of processed food, saturated fat, and simple sugar which appears to be beneficial to cognitive health. Despite inconclusive evidence from both approaches, diet and exercise, beneficial for other diseases, remains to be the two key modifiable factors for cognitive function. Large-scale prospective studies in multiethics population are required to provide stronger evidence in the future.

  12. Cognition and Depression: Current Status and Future Directions

    OpenAIRE

    Ian H Gotlib; Joormann, Jutta

    2010-01-01

    Cognitive theories of depression posit that people’s thoughts, inferences, attitudes, and interpretations, and the way in which they attend to and recall information, can increase their risk for depression. Three mechanisms have been implicated in the relation between biased cognitive processing and the dysregulation of emotion in depression: inhibitory processes and deficits in working memory, ruminative responses to negative mood states and negative life events, and the inability to use pos...

  13. Current status of research on cognitive therapy/cognitive behavior therapy in Japan.

    Science.gov (United States)

    Ono, Yutaka; Furukawa, Toshi A; Shimizu, Eiji; Okamoto, Yasumasa; Nakagawa, Akiko; Fujisawa, Daisuke; Nakagawa, Atsuo; Ishii, Tomoko; Nakajima, Satomi

    2011-03-01

    Cognitive therapy/cognitive behavior therapy was introduced into the field of psychiatry in the late 1980s in Japan, and the Japanese Association for Cognitive Therapy (JACT), founded in 2004, now has more than 1500 members. Along with such progress, awareness of the effectiveness of cognitive therapy/cognitive behavioral therapy has spread, not only among professionals and academics but also to the public. The Study Group of the Procedures and Effectiveness of Psychotherapy, funded by the Ministry of Health, Labor and Welfare, has conducted a series of studies on the effectiveness of cognitive therapy/cognitive behavior therapy since 2006 and shown that it is feasible for Japanese patients. As a result, in April 2010 cognitive therapy/cognitive behavior therapy for mood disorders was added to the national health insurance scheme in Japan. This marked a milestone in Japan's psychiatric care, where pharmacotherapy has historically been more common. In this article the authors review research on cognitive therapy/cognitive behavior therapy in Japan.

  14. Targeting the neurophysiology of cognitive systems with transcranial alternating current stimulation.

    Science.gov (United States)

    Fröhlich, Flavio; Sellers, Kristin K; Cordle, Asa L

    2015-02-01

    Cognitive impairment represents one of the most debilitating and most difficult symptom to treat of many psychiatric illnesses. Human neurophysiology studies have suggested that specific pathologies of cortical network activity correlate with cognitive impairment. However, we lack demonstration of causal relationships between specific network activity patterns and cognitive capabilities and treatment modalities that directly target impaired network dynamics of cognition. Transcranial alternating current stimulation (tACS), a novel non-invasive brain stimulation approach, may provide a crucial tool to tackle these challenges. Here, we propose that tACS can be used to elucidate the causal role of cortical synchronization in cognition and, eventually, to enhance pathologically weakened synchrony that may underlie cognitive deficits. To accelerate such development of tACS as a treatment for cognitive deficits, we discuss studies on tACS and cognition performed in healthy participants, according to the Research Domain Criteria of the National Institute of Mental Health.

  15. Conceptual Commitments of the LIDA Model of Cognition

    Science.gov (United States)

    Franklin, Stan; Strain, Steve; McCall, Ryan; Baars, Bernard

    2013-06-01

    Significant debate on fundamental issues remains in the subfields of cognitive science, including perception, memory, attention, action selection, learning, and others. Psychology, neuroscience, and artificial intelligence each contribute alternative and sometimes conflicting perspectives on the supervening problem of artificial general intelligence (AGI). Current efforts toward a broad-based, systems-level model of minds cannot await theoretical convergence in each of the relevant subfields. Such work therefore requires the formulation of tentative hypotheses, based on current knowledge, that serve to connect cognitive functions into a theoretical framework for the study of the mind. We term such hypotheses "conceptual commitments" and describe the hypotheses underlying one such model, the Learning Intelligent Distribution Agent (LIDA) Model. Our intention is to initiate a discussion among AGI researchers about which conceptual commitments are essential, or particularly useful, toward creating AGI agents.

  16. Vascular cognitive impairment: Current concepts and Indian perspective

    Directory of Open Access Journals (Sweden)

    Alladi Suvarna

    2010-10-01

    Full Text Available Cognitive impairment due to cerebrovascular disease is termed "Vascular Cognitive Impairment" (VCI and forms a spectrum that includes Vascular Dementia (VaD and milder forms of cognitive impairment referred to as Vascular Mild Cognitive Impairment (VaMCI. VCI represents a complex neurological disorder that occurs as a result of interaction between vascular risk factors such as hypertension, diabetes, obesity, dyslipidemia, and brain parenchymal changes such as macro and micro infarcts, haemorrhages, white matter changes, and brain atrophy occurring in an ageing brain. Mixed degenerative and vascular pathologies are increasingly being recognised and an interaction between the AD pathology, vascular risk factors, and strokes is now proposed. The high cardiovascular disease burden in India, increasing stroke incidence, and ageing population have contributed to large numbers of patients with VCI in India. Inadequate resources coupled with low awareness make it a problem that needs urgent attention, it is important identify patients at early stages of cognitive impairment, to treat appropriately and prevent progression to frank dementia.

  17. Toward a model-based cognitive neuroscience of mind wandering.

    Science.gov (United States)

    Hawkins, G E; Mittner, M; Boekel, W; Heathcote, A; Forstmann, B U

    2015-12-03

    People often "mind wander" during everyday tasks, temporarily losing track of time, place, or current task goals. In laboratory-based tasks, mind wandering is often associated with performance decrements in behavioral variables and changes in neural recordings. Such empirical associations provide descriptive accounts of mind wandering - how it affects ongoing task performance - but fail to provide true explanatory accounts - why it affects task performance. In this perspectives paper, we consider mind wandering as a neural state or process that affects the parameters of quantitative cognitive process models, which in turn affect observed behavioral performance. Our approach thus uses cognitive process models to bridge the explanatory divide between neural and behavioral data. We provide an overview of two general frameworks for developing a model-based cognitive neuroscience of mind wandering. The first approach uses neural data to segment observed performance into a discrete mixture of latent task-related and task-unrelated states, and the second regresses single-trial measures of neural activity onto structured trial-by-trial variation in the parameters of cognitive process models. We discuss the relative merits of the two approaches, and the research questions they can answer, and highlight that both approaches allow neural data to provide additional constraint on the parameters of cognitive models, which will lead to a more precise account of the effect of mind wandering on brain and behavior. We conclude by summarizing prospects for mind wandering as conceived within a model-based cognitive neuroscience framework, highlighting the opportunities for its continued study and the benefits that arise from using well-developed quantitative techniques to study abstract theoretical constructs.

  18. Considering digits in a current model of numerical development.

    Science.gov (United States)

    Roesch, Stephanie; Moeller, Korbinian

    2014-01-01

    Numerical cognition has long been considered the perfect example of abstract information processing. Nevertheless, there is accumulating evidence in recent years suggesting that the representation of number magnitude may not be entirely abstract but may present a specific case of embodied cognition rooted in the sensory and bodily experiences of early finger counting and calculating. However, so far none of the existing models of numerical development considers the influence of finger-based representations. Therefore, we make first suggestions on (i) how finger-based representations may be integrated into a current model of numerical development; and (ii) how they might corroborate the acquisition of basic numerical competencies at different development levels.

  19. A Cognitive Model of College Mathematics Placement

    Science.gov (United States)

    1989-08-01

    study focused on the precalculus -- calculus placement decision. The Cognitive model uses novel, or analysis level, placement test items in an attempt to...relative to the requirements of a precalculus course. Placement test scores may be partitioned to give analysis and non-analysis subtest scores which can...67 5.1.1 1989 Intercorrelations ....................................................................... 67 5.1.2 1989 Precalculus -Calculus

  20. 3D gender recognition using cognitive modeling

    DEFF Research Database (Denmark)

    Fagertun, Jens; Andersen, Tobias; Hansen, Thomas

    2013-01-01

    We use 3D scans of human faces and cognitive modeling to estimate the “gender strength”. The “gender strength” is a continuous class variable of the gender, superseding the traditional binary class labeling. To visualize some of the visual trends humans use when performing gender classification, ...

  1. Cognitive modelling of human temporal reasoning

    NARCIS (Netherlands)

    ter Meulen, AGB

    2003-01-01

    Modelling human reasoning characterizes the fundamental human cognitive capacity to describe our past experience and use it to form expectations as well as plan and direct our future actions. Natural language semantics analyzes dynamic forms of reasoning in which the real-time order determines the

  2. An Attributional (Cognitive) Model of Motivation.

    Science.gov (United States)

    Weiner, Bernard; And Others

    A cognitive model of motivation is proposed which postulates four components as the determinants of the actual and anticipated outcome of an achievement-related event. The four determinants are ability, effort, task difficulty, and luck. These factors may be classified as either internal or external sources of control, and as either stable or…

  3. Film and Cognition: A Critical Review of Current Theory.

    Science.gov (United States)

    Nadaner, Dan

    1984-01-01

    Three conceptual frameworks for examining the cognitive response to film are reviewed. It is suggested that a phenomenological rather than atomistic conception of the film-viewer interaction will be most useful for the generation of further studies in this area. (Author/RM)

  4. [Cancer-related Cognitive Impairment: Current Knowledge and Future Challenges].

    Science.gov (United States)

    Tanimukai, Hitoshi

    2015-01-01

    Cancer patients often suffer from various distresses, including cognitive impairment. Cognitive impairment during and after cancer diagnosis and treatment are collectively called "Cancer-related cognitive impairment (CRCI)". The number of publications about cognitive impairment due to cancer therapy, especially chemotherapy, hormonal therapy, and radiotherapy, has been growing. Patients often worry not only about their disease condition and therapies, but also experience concerns regarding their memory, attention, and ability to concentrate. Even subtle CRCI can have a significant impact on social relationships, the ability to work, undergo treatment, accomplish meaningful goals, and the quality of life. Longitudinal studies of cancer patients indicated that up to 75% experience CRCI during treatment. Furthermore, CRCI may persist for many years following treatment. However, it is not well understood by most physicians and medical staff. CRCI can be mediated through increased inflammatory cytokines and hormonal changes. In addition, the biology of the cancer, stress, and attentional fatigue can also contribute to CRCI. Genetic factors and co-occurring symptoms may explain some of the inter-individual variability in CRCI. Researchers and patients are actively trying to identify effective interventional methods and useful coping strategies. Many patients are willing to discuss their disease condition and future treatment with medical staff and/or their families. Some patients also hope to discuss their end-of-life care. However, it is difficult to express their will after developing cognitive impairment. Advance care planning (ACP) can help in such situations. This process involves discussion between a patient, their family, and clinicians to clarify and reflect on values, treatment preferences, and goals to develop a shared understanding of how end-of-life care should proceed. The number of cancer patients with cognitive impairment has been increasing owing to the

  5. Mathematical Cognition: A Volume in Current Perspectives on Cognition, Learning, and Instruction.

    Science.gov (United States)

    Royer, James M., Ed.

    This book deals addresses how the development of the human capacity for mathematical cognition occurs through educational experience. Chapters include: (1) "The Development of Math Competence in the Preschool and Early School Years: Cognitive Foundations and Instructional Strategies " (Sharon Griffin); (2) "Perspectives on Mathematics Strategy…

  6. Schizophrenia: an integrated sociodevelopmental-cognitive model.

    Science.gov (United States)

    Howes, Oliver D; Murray, Robin M

    2014-05-10

    Schizophrenia remains a major burden on patients and society. The dopamine hypothesis attempts to explain the pathogenic mechanisms of the disorder, and the neurodevelopmental hypothesis the origins. In the past 10 years an alternative, the cognitive model, has gained popularity. However, the first two theories have not been satisfactorily integrated, and the most influential iteration of the cognitive model makes no mention of dopamine, neurodevelopment, or indeed the brain. In this Review we show that developmental alterations secondary to variant genes, early hazards to the brain, and childhood adversity sensitise the dopamine system, and result in excessive presynaptic dopamine synthesis and release. Social adversity biases the cognitive schema that the individual uses to interpret experiences towards paranoid interpretations. Subsequent stress results in dysregulated dopamine release, causing the misattribution of salience to stimuli, which are then misinterpreted by the biased cognitive processes. The resulting paranoia and hallucinations in turn cause further stress, and eventually repeated dopamine dysregulation hardwires the psychotic beliefs. Finally, we consider the implications of this model for understanding and treatment of schizophrenia. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Assessing Fit of Cognitive Diagnostic Models: A Case Study

    Science.gov (United States)

    Sinharay, Sandip; Almond, Russell G.

    2007-01-01

    A cognitive diagnostic model uses information from educational experts to describe the relationships between item performances and posited proficiencies. When the cognitive relationships can be described using a fully Bayesian model, Bayesian model checking procedures become available. Checking models tied to cognitive theory of the domains…

  8. Assessing cognitive processes related to insomnia: A review and measurement guide for Harvey's cognitive model for the maintenance of insomnia.

    Science.gov (United States)

    Hiller, Rachel M; Johnston, Anna; Dohnt, Hayley; Lovato, Nicole; Gradisar, Michael

    2015-10-01

    Cognitive processes play an important role in the maintenance, and treatment of sleep difficulties, including insomnia. In 2002, a comprehensive model was proposed by Harvey. Since its inception the model has received >300 citations, and provided researchers and clinicians with a framework for understanding and treating insomnia. The aim of this review is two-fold. First, we review the current literature investigating each factor proposed in Harvey's cognitive model of insomnia. Second, we summarise the psychometric properties of key measures used to assess the model's factors and mechanisms. From these aims, we demonstrate both strengths and limitations of the current knowledge of appropriate measurements associated with the model. This review aims to stimulate and guide future research in this area; and provide an understanding of the resources available to measure, target, and resolve cognitive factors that may maintain chronic insomnia. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Effects of previous growth hormone excess and current medical treatment for acromegaly on cognition

    OpenAIRE

    Brummelman, Pauline; Koerts, Janneke; Dullaart, Robin P. F.; van den Berg, Gerrit; Tucha, Oliver; Wolffenbuttel, Bruce H R; van Beek, Andre P.

    2012-01-01

    Background In untreated acromegaly patients, decreased cognitive functioning is reported to be associated with the degree of growth hormone (GH) and IGF-1 excess. Whether previous GH excess or current medical treatment for acromegaly specifically affects cognition remains unclear. The aim of this study was to compare cognitive functioning of patients who are treated for acromegaly with patients with non-functioning pituitary adenomas (NFA). In addition, we assessed the influence of prolonged ...

  10. Exploring the dynamics of collective cognition using a computational model of cognitive dissonance

    Science.gov (United States)

    Smart, Paul R.; Sycara, Katia; Richardson, Darren P.

    2013-05-01

    The socially-distributed nature of cognitive processing in a variety of organizational settings means that there is increasing scientific interest in the factors that affect collective cognition. In military coalitions, for example, there is a need to understand how factors such as communication network topology, trust, cultural differences and the potential for miscommunication affects the ability of distributed teams to generate high quality plans, to formulate effective decisions and to develop shared situation awareness. The current paper presents a computational model and associated simulation capability for performing in silico experimental analyses of collective sensemaking. This model can be used in combination with the results of human experimental studies in order to improve our understanding of the factors that influence collective sensemaking processes.

  11. Social Cognition in Children: A Model for Intervention

    Science.gov (United States)

    Enright, Robert D.

    1976-01-01

    An attempt to formulate a model of social cognition which will describe what may be involved in making social cognitive inferences in children. Techniques for intervention are then derived from the model. (Author/NG)

  12. Multi-dimensional profiling of medical students' cognitive models about learning.

    Science.gov (United States)

    Askell-Williams, Helen; Lawson, Michael J

    2006-02-01

    In current constructivist paradigms, learners' previous subject-matter knowledge, or cognitive models, provide the foundations for the construction of new knowledge. Learners' cognitive models about learning also mediate students' capacities to learn in their chosen topics of study. The diverse backgrounds of students entering medicine suggest that they might come to medical studies equipped with a wide variety of cognitive models about learning. Some current theories tend to reduce students' cognitions about learning to parsimonious representations, such as surface-deep approaches or mastery-performance goals. It is possible that such reduced representations underrepresent, or misrepresent, the complexity of students' cognitive models about learning. Good quality teaching needs to take account of learners' cognitive models, not just about subject matter, but also about learning. This study investigated the diversity and complexity of medical students' cognitive models about learning. A total of 7 graduate entry, clinical-year medical students volunteered for in-depth interviews about learning. NUD*IST text analysis software and correspondence analysis were employed to identify dimensions and to profile students' responses. The correspondence analysis identified a significant 4-dimensional solution that illustrates the contributions of multiple variables to students' cognitive models about learning. Individual profiles highlight diversity between participants. This study provides evidence that students' cognitive models about learning are complex and highly differentiated. Representations of what students know about learning need to take account of such complexity in order to inform instructional practice more adequately.

  13. Effects of previous growth hormone excess and current medical treatment for acromegaly on cognition

    NARCIS (Netherlands)

    Brummelman, Pauline; Koerts, Janneke; Dullaart, Robin P. F.; van den Berg, Gerrit; Tucha, Oliver; Wolffenbuttel, Bruce H. R.; van Beek, Andre P.

    2012-01-01

    Background In untreated acromegaly patients, decreased cognitive functioning is reported to be associated with the degree of growth hormone (GH) and IGF-1 excess. Whether previous GH excess or current medical treatment for acromegaly specifically affects cognition remains unclear. The aim of this

  14. Effects of previous growth hormone excess and current medical treatment for acromegaly on cognition

    NARCIS (Netherlands)

    Brummelman, Pauline; Koerts, Janneke; Dullaart, Robin P. F.; van den Berg, Gerrit; Tucha, Oliver; Wolffenbuttel, Bruce H. R.; van Beek, Andre P.

    2012-01-01

    Background In untreated acromegaly patients, decreased cognitive functioning is reported to be associated with the degree of growth hormone (GH) and IGF-1 excess. Whether previous GH excess or current medical treatment for acromegaly specifically affects cognition remains unclear. The aim of this st

  15. Experimental pain processing in individuals with cognitive impairment: current state of the science.

    Science.gov (United States)

    Defrin, Ruth; Amanzio, Martina; de Tommaso, Marina; Dimova, Violeta; Filipovic, Sasa; Finn, David P; Gimenez-Llort, Lydia; Invitto, Sara; Jensen-Dahm, Christina; Lautenbacher, Stefan; Oosterman, Joukje M; Petrini, Laura; Pick, Chaim G; Pickering, Gisele; Vase, Lene; Kunz, Miriam

    2015-08-01

    Cognitive impairment (CI) can develop during the course of ageing and is a feature of many neurological and neurodegenerative diseases. Many individuals with CI have substantial, sustained, and complex health care needs, which frequently include pain. However, individuals with CI can have difficulty communicating the features of their pain to others, which in turn presents a significant challenge for effective diagnosis and treatment of their pain. Herein, we review the literature on responsivity of individuals with CI to experimental pain stimuli. We discuss pain responding across a large number of neurological and neurodegenerative disorders in which CI is typically present. Overall, the existing data suggest that pain processing is altered in most individuals with CI compared with cognitively intact matched controls. The precise nature of these alterations varies with the type of CI (or associated clinical condition) and may also depend on the type of pain stimulation used and the type of pain responses assessed. Nevertheless, it is clear that regardless of the etiology of CI, patients do feel noxious stimuli, with more evidence for hypersensitivity than hyposensitivity to these stimuli compared with cognitively unimpaired individuals. Our current understanding of the neurobiological mechanisms underpinning these alterations is limited but may be enhanced through the use of animal models of CI, which also exhibit alterations in nociceptive responding. Further research using additional behavioural indices of pain is warranted. Increased understanding of altered experimental pain processing in CI will facilitate the development of improved diagnostic and therapeutic approaches for pain in individuals with CI.

  16. Transcranial alternating current stimulation: a review of the underlying mechanisms and modulation of cognitive processes

    National Research Council Canada - National Science Library

    Herrmann, Christoph S; Rach, Stefan; Neuling, Toralf; Strüber, Daniel

    2013-01-01

    .... Particularly, tACS offers the unique opportunity to causally link brain oscillations of a specific frequency range to cognitive processes, because it uses sinusoidal currents that are bound to one frequency only...

  17. Evaluation of Model Fit in Cognitive Diagnosis Models

    Science.gov (United States)

    Hu, Jinxiang; Miller, M. David; Huggins-Manley, Anne Corinne; Chen, Yi-Hsin

    2016-01-01

    Cognitive diagnosis models (CDMs) estimate student ability profiles using latent attributes. Model fit to the data needs to be ascertained in order to determine whether inferences from CDMs are valid. This study investigated the usefulness of some popular model fit statistics to detect CDM fit including relative fit indices (AIC, BIC, and CAIC),…

  18. Does transcranial direct current stimulation enhance cognitive and motor functions in the ageing brain? A systematic review and meta- analysis.

    Science.gov (United States)

    Summers, Jeffery J; Kang, Nyeonju; Cauraugh, James H

    2016-01-01

    The use of transcranial direct current stimulation (tDCS) to enhance cognitive and motor functions has enjoyed a massive increase in popularity. Modifying neuroplasticity via non-invasive cortical stimulation has enormous potential to slow or even reverse declines in functions associated with ageing. The current meta-analysis evaluated the effects of tDCS on cognitive and motor performance in healthy older adults. Of the 81 studies identified, 25 qualified for inclusion. A random effects model meta-analysis revealed a significant overall standardized mean difference equal to 0.53 (SE=0.09; medium heterogeneity: I(2)=57.08%; and high fail-safe: N=448). Five analyses on moderator variables indicated significant tDCS beneficial effects: (a) on both cognitive and motor task performances, (b) across a wide-range of cognitive tasks, (c) on specific brain areas, (d) stimulation offline (before) or online (during) the cognitive and motor tasks. Although the meta-analysis revealed robust support for enhancing both cognitive and motor performance, we outline a number of caveats on the use of tDCS.

  19. Quantum-like Modeling of Cognition

    Directory of Open Access Journals (Sweden)

    Andrei eKhrennikov

    2015-09-01

    Full Text Available This paper begins with a historical review of the mutual influence of physics and psychology, from Freud's invention of psychic energy inspired by von Boltzmann' thermodynamics to the enrichment quantum physics gained from the side of psychology by the notion of complementarity (the invention of Niels Bohr who was inspired by William James, besides we consider the resonance of the correspondence between Wolfgang Pauli and Carl Jung in both physics and psychology. Then we turn to the problem of development of mathematical models for laws of thought starting with Boolean logic and progressing towards foundations of classical probability theory. Interestingly, the laws of classical logic and probability are routinely violated not only by quantum statistical phenomena but by cognitive phenomena as well. This is yet another common feature between quantum physics and psychology.In particular, cognitive data can exhibit a kind of the probabilistic interference effect. This similarity with quantum physics convinced a multi-disciplinary group of scientists (physicists, psychologists, economists, sociologists to apply the mathematical apparatus of quantum mechanics to modeling of cognition. We illustrate this activity by considering a few concrete phenomena: the order and disjunction effects, recognition of ambiguous figures, categorization-decision making.In Appendix 1 we briefly present essentials of theory of contextual probability and a method of representations of contextual probabilities by complex probability amplitudes(solution of the ``inverse Born's problem'' based on a quantum-like representation algorithm (QLRA.

  20. Quantum-like Modeling of Cognition

    Science.gov (United States)

    Khrennikov, Andrei

    2015-09-01

    This paper begins with a historical review of the mutual influence of physics and psychology, from Freud's invention of psychic energy inspired by von Boltzmann' thermodynamics to the enrichment quantum physics gained from the side of psychology by the notion of complementarity (the invention of Niels Bohr who was inspired by William James), besides we consider the resonance of the correspondence between Wolfgang Pauli and Carl Jung in both physics and psychology. Then we turn to the problem of development of mathematical models for laws of thought starting with Boolean logic and progressing towards foundations of classical probability theory. Interestingly, the laws of classical logic and probability are routinely violated not only by quantum statistical phenomena but by cognitive phenomena as well. This is yet another common feature between quantum physics and psychology. In particular, cognitive data can exhibit a kind of the probabilistic interference effect. This similarity with quantum physics convinced a multi-disciplinary group of scientists (physicists, psychologists, economists, sociologists) to apply the mathematical apparatus of quantum mechanics to modeling of cognition. We illustrate this activity by considering a few concrete phenomena: the order and disjunction effects, recognition of ambiguous figures, categorization-decision making. In Appendix 1 we briefly present essentials of theory of contextual probability and a method of representations of contextual probabilities by complex probability amplitudes (solution of the ``inverse Born's problem'') based on a quantum-like representation algorithm (QLRA).

  1. An introduction to model-based cognitive neuroscience

    NARCIS (Netherlands)

    Forstmann, B.U.; Wagenmakers, E.-J.

    2015-01-01

    Two recent innovations, the emergence of formal cognitive models and the addition of cognitive neuroscience data to the traditional behavioral data, have resulted in the birth of a new, interdisciplinary field of study: model-based cognitive neuroscience. Despite the increasing scientific interest

  2. Models of cognitive behavior in nuclear power plant personnel. A feasibility study: main report. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Woods, D.D.; Roth, E.M.; Hanes, L.F.

    1986-07-01

    This report contains the results of a feasibility study to determine if the current state of models human cognitive activities can serve as the basis for improved techniques for predicting human error in nuclear power plants emergency operations. Based on the answer to this questions, two subsequent phases of research are planned. Phase II is to develop a model of cognitive activities, and Phase III is to test the model. The feasibility study included an analysis of the cognitive activities that occur in emergency operations and an assessment of the modeling concepts/tools available to capture these cognitive activities. The results indicated that a symbolic processing (or artificial intelligence) model of cognitive activities in nuclear power plants is both desirable and feasible. This cognitive model can be built upon the computational framework provided by an existing artificial intelligence system for medical problem solving called Caduceus. The resulting cognitive model will increase the capability to capture the human contribution to risk in probabilistic risk assessments studies. Volume I summarizes the major findings and conclusions of the study. Volume II provides a complete description of the methods and results, including a synthesis of the cognitive activities that occur during emergency operations, and a literature review on cognitive modeling relevant to nuclear power plants. 112 refs., 10 figs.

  3. User-oriented and cognitive models of information retrieval

    DEFF Research Database (Denmark)

    Järvelin, Kalervo; Ingwersen, Peter

    2010-01-01

    The domain of user-oriented and cognitive IR is first discussed, followed by a discussion on the dimensions and types of models one may build for the domain.  The focus of the present entry is on the models of user-oriented and cognitive IR, not on their empirical applications. Several models...... with different emphases on user-oriented and cognitive IR are presented - ranging from overall approaches and relevance models to procedural models, cognitive models, and task-based models. The present entry does not discuss empirical findings based on the models....

  4. User-oriented and cognitive models of information retrieval

    DEFF Research Database (Denmark)

    Järvelin, Kalervo; Ingwersen, Peter

    2010-01-01

    The domain of user-oriented and cognitive IR is first discussed, followed by a discussion on the dimensions and types of models one may build for the domain.  The focus of the present entry is on the models of user-oriented and cognitive IR, not on their empirical applications. Several models...... with different emphases on user-oriented and cognitive IR are presented - ranging from overall approaches and relevance models to procedural models, cognitive models, and task-based models. The present entry does not discuss empirical findings based on the models....

  5. Exploration for Understanding in Cognitive Modeling

    Science.gov (United States)

    Gluck, Kevin; Stanley, Clayton; Moore, L.; Reitter, David; Halbrügge, Marc

    2010-12-01

    The cognitive modeling and artificial general intelligence research communities may reap greater scientific return on research investments - may achieve an improved understanding of architectures and models - if there is more emphasis on systematic sensitivity and necessity analyses during model development, evaluation, and comparison. We demonstrate this methodological prescription with two of the models submitted for the Dynamic Stocks and Flows (DSF) Model Comparison Challenge, exploring the complex interactions among architectural mechanisms, knowledge-level strategy variants, and task conditions. To cope with the computational demands of these analyses we use a predictive analytics approach similar to regression trees, combined with parallelization on high performance computing clusters, to enable large scale, simultaneous search and exploration.

  6. Robot Cognitive Control with a Neurophysiologically Inspired Reinforcement Learning Model

    Science.gov (United States)

    Khamassi, Mehdi; Lallée, Stéphane; Enel, Pierre; Procyk, Emmanuel; Dominey, Peter F.

    2011-01-01

    A major challenge in modern robotics is to liberate robots from controlled industrial settings, and allow them to interact with humans and changing environments in the real-world. The current research attempts to determine if a neurophysiologically motivated model of cortical function in the primate can help to address this challenge. Primates are endowed with cognitive systems that allow them to maximize the feedback from their environment by learning the values of actions in diverse situations and by adjusting their behavioral parameters (i.e., cognitive control) to accommodate unexpected events. In such contexts uncertainty can arise from at least two distinct sources – expected uncertainty resulting from noise during sensory-motor interaction in a known context, and unexpected uncertainty resulting from the changing probabilistic structure of the environment. However, it is not clear how neurophysiological mechanisms of reinforcement learning and cognitive control integrate in the brain to produce efficient behavior. Based on primate neuroanatomy and neurophysiology, we propose a novel computational model for the interaction between lateral prefrontal and anterior cingulate cortex reconciling previous models dedicated to these two functions. We deployed the model in two robots and demonstrate that, based on adaptive regulation of a meta-parameter β that controls the exploration rate, the model can robustly deal with the two kinds of uncertainties in the real-world. In addition the model could reproduce monkey behavioral performance and neurophysiological data in two problem-solving tasks. A last experiment extends this to human–robot interaction with the iCub humanoid, and novel sources of uncertainty corresponding to “cheating” by the human. The combined results provide concrete evidence for the ability of neurophysiologically inspired cognitive systems to control advanced robots in the real-world. PMID:21808619

  7. Cognitive rehabilitation after severe acquired brain injury: current evidence and future directions.

    Science.gov (United States)

    De Luca, Rosaria; Calabrò, Rocco Salvatore; Bramanti, Placido

    2016-07-25

    Severe acquired brain injury (SABI) is damage to the brain, occurring after birth from traumatic or non-traumatic causes, and often resulting in deterioration of physical, cognitive, and emotional functions. Cognitive rehabilitation (CR) is aimed to help brain-injured or otherwise cognitively impaired individuals to restore normal functioning, or to compensate for cognitive deficits. Over the last years, the development of new technologies in the field of CR has led to a growing use of computer-based cognitive tools in patients with SABI. This review aims to investigate the efficacy of CR in individuals suffering from SABI, and evaluates the role of virtual reality and other innovative technologies in improving behavioural and functional outcomes. The current evidence for CR in the treatment of SABI-related deficits does not allow conclusive results to be achieved and further research is needed to identity the patient and treatment factors that contribute to successful outcomes.

  8. A pilot study of cognitive training with and without transcranial direct current stimulation to improve cognition in older persons with HIV-related cognitive impairment

    Directory of Open Access Journals (Sweden)

    Ownby RL

    2016-10-01

    Full Text Available Raymond L Ownby,1 Amarilis Acevedo2 1Department of Psychiatry and Behavioral Medicine, 2College of Psychology, Nova Southeastern University, Fort Lauderdale, FL, USA Background: In spite of treatment advances, HIV infection is associated with cognitive deficits. This is even more important as many persons with HIV infection age and experience age-related cognitive impairments. Both computer-based cognitive training and transcranial direct current stimulation (tDCS have shown promise as interventions to improve cognitive function. In this study, we investigate the acceptability and efficacy of cognitive training with and without tDCS in older persons with HIV. Patients and methods: In this single-blind randomized study, participants were 14 individuals of whom 11 completed study procedures (mean age =51.5 years; nine men and two women with HIV-related mild neurocognitive disorder. Participants completed a battery of neuropsychological and self-report measures and then six 20-minute cognitive training sessions while receiving either active or sham anodal tDCS over the left dorsolateral prefrontal cortex. After training, participants completed the same measures. Success of the blind and participant reactions were assessed during a final interview. Assessments were completed by an assessor blind to treatment assignment. Pre- and post-training changes were evaluated via analysis of covariance yielding estimates of effect size. Results: All participants believed that they had been assigned to active treatment; nine of the 11 believed that the intervention had improved their cognitive functioning. Both participants who felt the intervention was ineffective were assigned to the sham condition. None of the planned tested interactions of time with treatment was significant, but 12 of 13 favored tDCS (P=0.08. All participants indicated that they would participate in similar studies in the future. Conclusion: Results show that both cognitive training via

  9. Transcranial alternating current stimulation: a review of the underlying mechanisms and modulation of cognitive processes.

    Science.gov (United States)

    Herrmann, Christoph S; Rach, Stefan; Neuling, Toralf; Strüber, Daniel

    2013-01-01

    Brain oscillations of different frequencies have been associated with a variety of cognitive functions. Convincing evidence supporting those associations has been provided by studies using intracranial stimulation, pharmacological interventions and lesion studies. The emergence of novel non-invasive brain stimulation techniques like repetitive transcranial magnetic stimulation (rTMS) and transcranial alternating current stimulation (tACS) now allows to modulate brain oscillations directly. Particularly, tACS offers the unique opportunity to causally link brain oscillations of a specific frequency range to cognitive processes, because it uses sinusoidal currents that are bound to one frequency only. Using tACS allows to modulate brain oscillations and in turn to influence cognitive processes, thereby demonstrating the causal link between the two. Here, we review findings about the physiological mechanism of tACS and studies that have used tACS to modulate basic motor and sensory processes as well as higher cognitive processes like memory, ambiguous perception, and decision making.

  10. Can Transcranial Direct Current Stimulation Improve Cognitive Functioning in Adults with Schizophrenia?

    Science.gov (United States)

    Schretlen, David J; van Steenburgh, Joseph J; Varvaris, Mark; Vannorsdall, Tracy D; Andrejczuk, Megan A; Gordon, Barry

    2014-11-03

    Cognitive impairment is nearly ubiquitous in schizophrenia. First-degree relatives of persons with schizophrenia often show similar but milder deficits. Current methods for the treatment of schizophrenia are often ineffective in cognitive remediation. Since transcranial direct current stimulation (tDCS) can enhance cognitive functioning in healthy adults, it might provide a viable option to enhance cognition in schizophrenia. We sought to explore whether tDCS can be tolerated by persons with schizophrenia and potentially improve their cognitive functioning. We examined the effects of anodal versus cathodal tDCS on working memory and other cognitive tasks in five outpatients with schizophrenia and six first-degree relatives of persons with schizophrenia. Each participant completed tasks thought to be mediated by the prefrontal cortex during two 30-minute sessions of tDCS to the left and right dorsolateral prefrontal cortex (DLPFC). Anodal stimulation over the left DLPFC improved performance relative to cathodal stimulation on measures of working memory and aspects of verbal fluency relevant to word retrieval. The patient group showed differential changes in novel design production without alteration of overall productivity, suggesting that tDCS might be capable of altering selfmonitoring and executive control. All participants tolerated tDCS well. None withdrew from the study or experienced any adverse reaction. We conclude that adults with schizophrenia can tolerate tDCS while engaging in cognitive tasks and that tDCS can alter their performance.

  11. Current Challenges in Dynamo Modeling

    Science.gov (United States)

    Glatzmaier, G. A.

    2001-12-01

    Three-dimensional, dynamically self-consistent, numerical simulations have been used for two decades to study the generation of global magnetic fields in the deep fluid interiors of planets and stars. In particular, the number of geodynamo models has increased significantly within the last five years. These simulations of magnetic field generation by laminar convection have provided considerable insight to the dynamo process and have produced large-scale fields similar to those observed. However, no global convective dynamo simulation has yet been able to afford the spatial resolution required to simulate turbulent convection, which surely must exist in these low-viscosity fluids. They have all employed greatly enhanced eddy diffusivities to stabilize the low resolution numerical solutions and crudely account for the transport and mixing by the unresolved turbulence. A grand challenge for the next generation of geodynamo models is to produce a simulation with the thermal and viscous (eddy) diffusivities set no larger than the actual magnetic diffusivity of the Earth's fluid core (2 m2/s), while using the core's dimensions, mass, rotation rate and heat flow. This would correspond to the Ekman and magnetic Ekman numbers both set to 10-9 and the Rayleigh number being many orders of magnitude greater than critical. Dynamo models for stars and planets present an additional complication: the large variation of density with radius. A grand challenge for the next generation of these models is to reach similarly low Ekman numbers and high Rayleigh numbers with a density that decreases by at least three orders of magnitude from the base of the convection zone to the model's outer boundary. The advances in numerical methods and massively parallel computing needed to meet these challenges will be discussed.

  12. Mild Cognitive Impairment in Parkinson’s Disease: A Review of Current Concepts

    Directory of Open Access Journals (Sweden)

    Natalie C. Palavra

    2013-01-01

    Full Text Available Mild Cognitive Impairment in Parkinson’s Disease (PD-MCI is common and may be associated with accelerated progression to dementia. Considering the importance of this emerging entity, new diagnostic criteria have recently been proposed. Early recognition and accurate classification of PD-MCI could offer opportunities for novel therapeutic interventions. This review discusses current definitions for PD-MCI, the screening tools used, the pattern of cognitive deficits observed, and the predictors of cognitive decline and transition to Parkinson’s Disease Dementia. Emerging biomarkers, which may aid diagnosis, are also explored and the role of novel treatment options is considered.

  13. Comparative analysis of cognitive tasks for modeling mental workload with electroencephalogram.

    Science.gov (United States)

    Hwang, Taeho; Kim, Miyoung; Hwangbo, Minsu; Oh, Eunmi

    2014-01-01

    Previous electroencephalogram (EEG) studies have shown that cognitive workload can be estimated by using several types of cognitive tasks. In this study, we attempted to characterize cognitive tasks that have been used to manipulate workload for generating classification models. We carried out a comparative analysis between two representative types of working memory tasks: the n-back task and the mental arithmetic task. Based on experiments with 7 healthy subjects using Emotiv EPOC, we compared the consistency, robustness, and efficiency of each task in determining cognitive workload in a short training session. The mental arithmetic task seems consistent and robust in manipulating clearly separable high and low levels of cognitive workload with less training. In addition, the mental arithmetic task shows consistency despite repeated usage over time and without notable task adaptation in users. The current study successfully quantifies the quality and efficiency of cognitive workload modeling depending on the type and configuration of training tasks.

  14. Current Trends and Research Challenges in Spectrum-Sensing for Cognitive Radios

    Directory of Open Access Journals (Sweden)

    Roopali Garg

    2016-07-01

    Full Text Available The ever increasing demand of wireless communication systems has led to search of suitable spectrum bands for transmission of data. The research in the past has revealed that radio spectrum is under-utilized in most of the scenarios. This prompted the scientist to seek a solution to utilize the spectrum efficiently. Cognitive Radios provided an answer to the problem by sensing the idle (licensed bands and allowing (secondary users to transmit in these idle spaces. Spectrum sensing forms the main block of cognition cycle. This paper reviews the current trends in research in the domain of spectrum sensing. The author describes the type of channel being modelled, diversity combining schemes used, optimal algorithms applied at fusion centre, spectrum sensing techniques employed. Further, the research challenges are discussed. It is presented that various attributes like sensing time, throughput, rate reliability, optimum cooperative users, sensing frequency etc. needs to be addressed. A trade-off needs to be established to optimize two opposing parameters like sensing and throughput.

  15. Avian Models for Human Cognitive Neuroscience: A Proposal.

    Science.gov (United States)

    Clayton, Nicola S; Emery, Nathan J

    2015-06-17

    Research on avian cognitive neuroscience over the past two decades has revealed the avian brain to be a better model for understanding human cognition than previously thought, despite differences in the neuroarchitecture of avian and mammalian brains. The brain, behavior, and cognition of songbirds have provided an excellent model of human cognition in one domain, namely learning human language and the production of speech. There are other important behavioral candidates of avian cognition, however, notably the capacity of corvids to remember the past and plan for the future, as well as their ability to think about another's perspective, and physical reasoning. We review this work and assess the evidence that the corvid brain can support such a cognitive architecture. We propose potential applications of these behavioral paradigms for cognitive neuroscience, including recent work on single-cell recordings and neuroimaging in corvids. Finally, we discuss their impact on understanding human developmental cognition. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Some Instructional Implications from a Mathematical Model of Cognitive Development.

    Science.gov (United States)

    Mierkiewicz, Diane B.

    Cognitive development and various educational implications are discussed in terms of Donald Saari's model of the interaction of a learner and the enviroment and the constraints imposed by the inefficiency of the learner's cognitive system. Saari proposed a hierarchical system of cognitive structures such that the relationships between structures…

  17. Computational Grounded Cognition: A New Alliance between Grounded Cognition and Computational Modeling

    Directory of Open Access Journals (Sweden)

    Giovanni ePezzulo

    2013-01-01

    Full Text Available Grounded theories assume that there is no central module for cognition. According to this view, all cognitive phenomena, including those considered the province of amodal cognition such as reasoning, numeric and language processing, are ultimately grounded in (and emerge from a variety of bodily, affective, perceptual and motor processes. The development and expression of cognition is constrained by the embodiment of cognitive agents and various contextual factors (physical and social in which they are immersed. The grounded framework has received numerous empirical confirmations. Still, there are very few explicit computational models that implement grounding in sensory, motor and affective processes as intrinsic to cognition, and demonstrate that grounded theories can mechanistically implement higher cognitive abilities. We propose a new alliance between grounded cognition and computational modeling towards a novel multidisciplinary enterprise: Computational Grounded Cognition. We clarify the defining features of this novel approach and emphasize the importance of using the methodology of Cognitive Robotics, which permits simultaneous consideration of multiple aspects of grounding, embodiment, and situatedness, showing how they constrain the development and expression of cognition.

  18. Cyberpsychology: a human-interaction perspective based on cognitive modeling.

    Science.gov (United States)

    Emond, Bruno; West, Robert L

    2003-10-01

    This paper argues for the relevance of cognitive modeling and cognitive architectures to cyberpsychology. From a human-computer interaction point of view, cognitive modeling can have benefits both for theory and model building, and for the design and evaluation of sociotechnical systems usability. Cognitive modeling research applied to human-computer interaction has two complimentary objectives: (1) to develop theories and computational models of human interactive behavior with information and collaborative technologies, and (2) to use the computational models as building blocks for the design, implementation, and evaluation of interactive technologies. From the perspective of building theories and models, cognitive modeling offers the possibility to anchor cyberpsychology theories and models into cognitive architectures. From the perspective of the design and evaluation of socio-technical systems, cognitive models can provide the basis for simulated users, which can play an important role in usability testing. As an example of application of cognitive modeling to technology design, the paper presents a simulation of interactive behavior with five different adaptive menu algorithms: random, fixed, stacked, frequency based, and activation based. Results of the simulation indicate that fixed menu positions seem to offer the best support for classification like tasks such as filing e-mails. This research is part of the Human-Computer Interaction, and the Broadband Visual Communication research programs at the National Research Council of Canada, in collaboration with the Carleton Cognitive Modeling Lab at Carleton University.

  19. Going beyond the unitary curve: incorporating richer cognition into agent-based water resources models

    Science.gov (United States)

    Kock, B. E.

    2008-12-01

    The increased availability and understanding of agent-based modeling technology and techniques provides a unique opportunity for water resources modelers, allowing them to go beyond traditional behavioral approaches from neoclassical economics, and add rich cognition to social-hydrological models. Agent-based models provide for an individual focus, and the easier and more realistic incorporation of learning, memory and other mechanisms for increased cognitive sophistication. We are in an age of global change impacting complex water resources systems, and social responses are increasingly recognized as fundamentally adaptive and emergent. In consideration of this, water resources models and modelers need to better address social dynamics in a manner beyond the capabilities of neoclassical economics theory and practice. However, going beyond the unitary curve requires unique levels of engagement with stakeholders, both to elicit the richer knowledge necessary for structuring and parameterizing agent-based models, but also to make sure such models are appropriately used. With the aim of encouraging epistemological and methodological convergence in the agent-based modeling of water resources, we have developed a water resources-specific cognitive model and an associated collaborative modeling process. Our cognitive model emphasizes efficiency in architecture and operation, and capacity to adapt to different application contexts. We describe a current application of this cognitive model and modeling process in the Arkansas Basin of Colorado. In particular, we highlight the potential benefits of, and challenges to, using more sophisticated cognitive models in agent-based water resources models.

  20. Considering digits in a current model of numerical development

    Science.gov (United States)

    Roesch, Stephanie; Moeller, Korbinian

    2015-01-01

    Numerical cognition has long been considered the perfect example of abstract information processing. Nevertheless, there is accumulating evidence in recent years suggesting that the representation of number magnitude may not be entirely abstract but may present a specific case of embodied cognition rooted in the sensory and bodily experiences of early finger counting and calculating. However, so far none of the existing models of numerical development considers the influence of finger-based representations. Therefore, we make first suggestions on (i) how finger-based representations may be integrated into a current model of numerical development; and (ii) how they might corroborate the acquisition of basic numerical competencies at different development levels. PMID:25628559

  1. Transcranial direct current stimulation and cognitive training in the rehabilitation of Alzheimer disease: A case study.

    Science.gov (United States)

    Penolazzi, Barbara; Bergamaschi, Susanna; Pastore, Massimiliano; Villani, Daniele; Sartori, Giuseppe; Mondini, Sara

    2015-01-01

    In the present study we tested the cognitive effects of transcranial direct current stimulation (tDCS) in a case of probable Alzheimer disease (AD). The patient (male, 60 years, mild AD) underwent two cycles of treatments, separated by 2 months. In the first cycle, active stimulation (10 sessions, 2 mA for 20 min; anode over the left dorsolateral prefrontal cortex) was followed by computerised tasks (CTs) specifically chosen to engage the most impaired cognitive processes in the patient (tDCS+CT condition). In the second cycle, which was structured as the first, CTs were administered after placebo stimulation (sham+CT condition). Effects on cognitive performance were evaluated not only by the CTs, but also by neuropsychological tests assessing global cognitive functioning. Statistical analyses revealed that whereas the tDCS+CT condition had few effects on the CTs, it induced a stability of the patient's global cognitive functioning lasting approximately 3 months, which was not achieved when the patient underwent sham+CT condition. Therefore, the synergetic use of tDCS and CTs appeared to slow down the cognitive decline of our patient. This preliminary result, although in need of further confirmation, suggests the potentiality of tDCS as an adjuvant tool for cognitive rehabilitation in AD.

  2. Complex versus Complicated Models of Cognition

    NARCIS (Netherlands)

    den Hartigh, Ruud; Cox, Ralf; van Geert, Paul; Magnani, Lorenzo; Bertolotti, Tommaso

    2016-01-01

    As humans, we continuously adapt our behavior to changes in our environment, and our cognitive abilities continuously develop over time. A major question for scientists has been to discover the (cognitive) mechanism that underlies the control of human behavior in real-time, as well as cognitive deve

  3. Cognitive-Operative Model of Intelligent Learning Systems Behavior

    Science.gov (United States)

    Laureano-Cruces, Ana Lilia; Ramirez-Rodriguez, Javier; Mora-Torres, Martha; de Arriaga, Fernando; Escarela-Perez, Rafael

    2010-01-01

    In this paper behavior during the teaching-learning process is modeled by means of a fuzzy cognitive map. The elements used to model such behavior are part of a generic didactic model, which emphasizes the use of cognitive and operative strategies as part of the student-tutor interaction. Examples of possible initial scenarios for the…

  4. Cognitive-Operative Model of Intelligent Learning Systems Behavior

    Science.gov (United States)

    Laureano-Cruces, Ana Lilia; Ramirez-Rodriguez, Javier; Mora-Torres, Martha; de Arriaga, Fernando; Escarela-Perez, Rafael

    2010-01-01

    In this paper behavior during the teaching-learning process is modeled by means of a fuzzy cognitive map. The elements used to model such behavior are part of a generic didactic model, which emphasizes the use of cognitive and operative strategies as part of the student-tutor interaction. Examples of possible initial scenarios for the…

  5. An introduction to good practices in cognitive modeling

    NARCIS (Netherlands)

    A. Heathcote; S.D. Brown; E.-J. Wagenmakers

    2015-01-01

    Cognitive modeling can provide important insights into the underlying causes of behavior, but the validity of those insights rests on careful model development and checking. We provide guidelines on five important aspects of the practice of cognitive modeling: parameter recovery, testing selective i

  6. Modeling of Current Transformers Under Saturation Conditions

    Directory of Open Access Journals (Sweden)

    Martin Prochazka

    2006-01-01

    Full Text Available During a short circuit the input signal of the relay can be distort by the magnetic core saturation of the current transformer. It is useful to verify the behavior of CT by a mathematical model. The paper describes one phase and three phase models and it presents some methods of how to analyze and classify a deformed secondary current

  7. Models and theories of brain function in cognition within a framework of behavioral cognitive psychology.

    Science.gov (United States)

    Karakaş, Sirel; Başar, Erol

    2006-05-01

    The present article presents a nonexhaustive collection of contemporary models and theories on brain function and discusses these models and theories within a framework of explanatory formulations in behavioral cognitive psychology. Such a mission was accomplished by evaluating the cognitive implications in the explanatory formulations with respect to established laws/principles and models/theories of behavioral cognitive psychology. The article also points to problem areas of behavioral cognitive psychology for which the explanatory formulations have solutions to offer. The article shows that the cinematographic hypothesis, the new visual model, the synergetic model, and the theory of whole-brain-work emphasize various aspects of perception. The formulations on P300 theory emphasize attention and also working memory. The theory on cognits is a comprehensive account of memory. Characteristic to all of these explanatory formulations and also to that on the complexity and its evolution and that on neurocognitive networks is the emphasis on selective distribution, integration to the point of supersynergy, and dynamicity. Such a viewpoint was not only applied to the operations of the brain but also of cognition. With such a conceptualization, the explanatory formulations could account for cognitive processes other than the ones emphasized. A common aspect in a majority of the formulations is the utilization of the oscillatory activity as the valid activity of the brain. The article points out that a frontier in cognitive psychophysiology would be the study of the genetics of brain oscillations.

  8. Visual behaviour analysis and driver cognitive model

    Energy Technology Data Exchange (ETDEWEB)

    Baujon, J.; Basset, M.; Gissinger, G.L. [Mulhouse Univ., (France). MIPS/MIAM Lab.

    2001-07-01

    Recent studies on driver behaviour have shown that perception - mainly visual but also proprioceptive perception - plays a key role in the ''driver-vehicle-road'' system and so considerably affects the driver's decision making. Within the framework of the behaviour analysis and studies low-cost system (BASIL), this paper presents a correlative, qualitative and quantitative study, comparing the information given by visual perception and by the trajectory followed. This information will help to obtain a cognitive model of the Rasmussen type according to different driver classes. Many experiments in real driving situations have been carried out for different driver classes and for a given trajectory profile, using a test vehicle and innovative, specially designed, real-time tools, such as the vision system or the positioning module. (orig.)

  9. Mindfulness-Based Cognitive Therapy: Further Issues in Current Evidence and Future Research

    Science.gov (United States)

    Williams, J. Mark G.; Russell, Ian; Russell, Daphne

    2008-01-01

    The authors respond to the article by H. F. Coelho, P. H. Canter, and E. Ernst (2007), which reviewed the current status of mindfulness-based cognitive therapy (MBCT). First, they clarify the randomization procedures in the 2 main MBCT trials. Second, they report posttreatment and follow-up data to show that trial participants allocated to…

  10. Modeling Cognitive Dysfunction in Neurofibromatosis-1

    OpenAIRE

    Diggs-Andrews, Kelly A.; David H Gutmann

    2013-01-01

    Cognitive dysfunction, including significant impairments in learning, behavior, and attention, is found in over 10% of children in the general population. However, in the common inherited cancer predisposition syndrome, Neurofibromatosis type 1 (NF1), the prevalence of these cognitive deficits approaches 70%. As a monogenic disorder, NF1 provides a unique genetic tool to identify and mechanistically dissect the molecular and cellular bases underlying cognitive dysfunction. In this review, we ...

  11. Developing a model of cognitive lockup for user interface engineering

    NARCIS (Netherlands)

    Mioch, T.; Looije, R.; Neerincx, M.A.

    2010-01-01

    This paper presents the development of a cognitive model of cognitive lockup: the tendency of humans to deal with disturbances sequentially, possibly overseeing crucial data from unattended resources so that serious task failures can appear—e.g., in a cockpit or control centre. The proposed model sh

  12. Developing a model of cognitive lockup for user interface engineering

    NARCIS (Netherlands)

    Mioch, T.; Looije, R.; Neerincx, M.A.

    2010-01-01

    This paper presents the development of a cognitive model of cognitive lockup: the tendency of humans to deal with disturbances sequentially, possibly overseeing crucial data from unattended resources so that serious task failures can appear—e.g., in a cockpit or control centre. The proposed model sh

  13. Framework of Pattern Recognition Model Based on the Cognitive Psychology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    According to the fundamental theory of visual cognition mechanism and cognitive psychology,the visual pattern recognition model is introduced briefly.Three pattern recognition models,i.e.template-based matching model,prototype-based matching model and feature-based matching model are built and discussed separately.In addition,the influence of object background information and visual focus point to the result of pattern recognition is also discussed with the example of recognition for fuzzy letters and figures.

  14. Cognitive Modeling of Video Game Player User Experience

    Science.gov (United States)

    Bohil, Corey J.; Biocca, Frank A.

    2010-01-01

    This paper argues for the use of cognitive modeling to gain a detailed and dynamic look into user experience during game play. Applying cognitive models to game play data can help researchers understand a player's attentional focus, memory status, learning state, and decision strategies (among other things) as these cognitive processes occurred throughout game play. This is a stark contrast to the common approach of trying to assess the long-term impact of games on cognitive functioning after game play has ended. We describe what cognitive models are, what they can be used for and how game researchers could benefit by adopting these methods. We also provide details of a single model - based on decision field theory - that has been successfUlly applied to data sets from memory, perception, and decision making experiments, and has recently found application in real world scenarios. We examine possibilities for applying this model to game-play data.

  15. Numerical modeling of transformer inrush currents

    Science.gov (United States)

    Cardelli, E.; Faba, A.

    2014-02-01

    This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.

  16. Numerical modeling of transformer inrush currents

    Energy Technology Data Exchange (ETDEWEB)

    Cardelli, E. [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy); Faba, A., E-mail: faba@unipg.it [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy)

    2014-02-15

    This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.

  17. Addressing contrasting cognitive models in scientific collaboration

    Science.gov (United States)

    Diviacco, P.

    2012-04-01

    If the social aspects of scientific communities and their internal dynamics is starting to be recognized and acknowledged in the everyday lives of scientists, it is rather difficult for them to find tools that could support their activities consistently with this perspective. Issues span from gathering researchers to mutual awareness, from information sharing to building meaning, with the last one being particularly critical in research fields as the geo-sciences, that deal with the reconstruction of unique, often non-reproducible, and contingent processes. Reasoning here is, in fact, mainly abductive, allowing multiple and concurrent explanations for the same phenomenon to coexist. Scientists bias one hypothesis over another not only on strictly logical but also on sociological motivations. Following a vision, scientists tend to evolve and isolate themselves from other scientists creating communities characterized by different cognitive models, so that after some time these become incompatible and scientists stop understanding each other. We address these problems as a communication issue so that the classic distinction into three levels (syntactic, semantic and pragmatic) can be used. At the syntactic level, we highlight non-technical obstacles that condition interoperability and data availability and transparency. At the semantic level, possible incompatibilities of cognitive models are particularly evident, so that using ontologies, cross-domain reconciliation should be applied. This is a very difficult task to perform since the projection of knowledge by scientists, in the designated community, is political and thus can create a lot of tension. The strategy we propose to overcome these issues pertains to pragmatics, in the sense that it is intended to acknowledge the cultural and personal factors each partner brings into the collaboration and is based on the idea that meaning should remain a flexible and contingent representation of possibly divergent views

  18. Modeling the effects of noninvasive transcranial brain stimulation at the biophysical, network, and cognitive Level

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Bergmann, Til Ole; Herz, Damian Marc

    2015-01-01

    Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how...... predictions regarding the impact of interindividual variations in cortical anatomy on the injected electric fields or the influence of the orientation of current flow on the physiological stimulation effects. (ii) Functional brain mapping of the spatiotemporal neural dynamics during cognitive tasks can...

  19. The transmission of early Christian thought : Toward a cognitive psychological model

    NARCIS (Netherlands)

    Czachesz, Istvan

    2007-01-01

    This article uses current developments in cognitive science to explore the emergence of early Christian religion. In particular, it considers Sperber's epidemiology model, Rubin's serial recall model, ritual form theory and Boyer's theory of religious concepts for understanding the transmission of

  20. Estimates of current debris from flux models

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1997-01-01

    Flux models that balance accuracy and simplicity are used to predict the growth of space debris to the present. Known and projected launch rates, decay models, and numerical integrations are used to predict distributions that closely resemble the current catalog-particularly in the regions containing most of the debris.

  1. Transcranial alternating current stimulation: A review of the underlying mechanisms and modulation of cognitive processes

    Directory of Open Access Journals (Sweden)

    Christoph S Herrmann

    2013-06-01

    Full Text Available Brain oscillations of different frequencies have been associated with a variety of cognitive functions. Convincing evidence supporting those associations has been provided by studies using intracranial stimulation, pharmacological interventions and lesion studies. The emergence of novel non-invasive brain stimulation techniques like repetitive transcranial magnetic stimulation (rTMS and transcranial alternating current stimulation (tACS now allows to modulate brain oscillations directly. Particularly, tACS offers the unique opportunity to causally link brain oscillations of a specific frequency range to cognitive processes, because it uses sinusoidal currents that are bound to one frequency only. Using tACS allows to modulate brain oscillations and in turn to influence cognitive processes, thereby demonstrating the causal link between the two. Here, we review findings about the physiological mechanism of tACS and studies that have used tACS to modulate basic motor and sensory processes as well as higher cognitive processes like memory, ambiguous perception, and decision making.

  2. Behavioral modeling of Digitally Adjustable Current Amplifier

    OpenAIRE

    Josef Polak; Lukas Langhammer; Jan Jerabek

    2015-01-01

    This article presents the digitally adjustable current amplifier (DACA) and its analog behavioral model (ABM), which is suitable for both ideal and advanced analyses of the function block using DACA as active element. There are four levels of this model, each being suitable for simulation of a certain degree of electronic circuits design (e.g. filters, oscillators, generators). Each model is presented through a schematic wiring in the simulation program OrCAD, including a description of equat...

  3. Development of cognitive model for navigating on the web

    NARCIS (Netherlands)

    Juvina, I.

    2006-01-01

    The objective of this thesis is to build a cognitive model of human performance in Web-assisted tasks. The research is driven by the following questions: What are the most important factors in determining success in Web-assisted tasks? What cognitive mechanisms are involved in these factors? What

  4. A Cognitive Developmental Model of Rigidity in Senescence.

    Science.gov (United States)

    Lapsley, Daniel K.; Enright, Robert D.

    1983-01-01

    The rigidity construct is reinterpreted in terms of the cognitive developmental approach. A review reveals both cognitive and developmental themes, with an emphasis on the structural and operational properties of rigidity. Notes weaknesses of previous approaches to rigidity and discusses implications and predictions from the proposed model.…

  5. Longitudinal mixed-effects models for latent cognitive function

    NARCIS (Netherlands)

    Hout, van den Ardo; Fox, Jean-Paul; Muniz-Terrera, Graciela

    2015-01-01

    A mixed-effects regression model with a bent-cable change-point predictor is formulated to describe potential decline of cognitive function over time in the older population. For the individual trajectories, cognitive function is considered to be a latent variable measured through an item response t

  6. Cognitive control in majority search: A computational modeling approach

    Directory of Open Access Journals (Sweden)

    Hongbin eWang

    2011-02-01

    Full Text Available Despite the importance of cognitive control in many cognitive tasks involving uncertainty, the computational mechanisms of cognitive control in response to uncertainty remain unclear. In this study, we develop biologically realistic neural network models to investigate the instantiation of cognitive control in a majority function task, where one determines the category to which the majority of items in a group belong. Two models are constructed, both of which include the same set of modules representing task-relevant brain functions and share the same model structure. However, with a critical change of a model parameter setting, the two models implement two different underlying algorithms: one for grouping search (where a subgroup of items are sampled and re-sampled until a congruent sample is found and the other for self-terminating search (where the items are scanned and counted one-by-one until the majority is decided. The two algorithms hold distinct implications for the involvement of cognitive control. The modeling results show that while both models are able to perform the task, the grouping search model fit the human data better than the self-terminating search model. An examination of the dynamics underlying model performance reveals how cognitive control might be instantiated in the brain via the V4-ACC-LPFC-IPS loop for computing the majority function.

  7. Cognitive control in majority search: a computational modeling approach.

    Science.gov (United States)

    Wang, Hongbin; Liu, Xun; Fan, Jin

    2011-01-01

    Despite the importance of cognitive control in many cognitive tasks involving uncertainty, the computational mechanisms of cognitive control in response to uncertainty remain unclear. In this study, we develop biologically realistic neural network models to investigate the instantiation of cognitive control in a majority function task, where one determines the category to which the majority of items in a group belong. Two models are constructed, both of which include the same set of modules representing task-relevant brain functions and share the same model structure. However, with a critical change of a model parameter setting, the two models implement two different underlying algorithms: one for grouping search (where a subgroup of items are sampled and re-sampled until a congruent sample is found) and the other for self-terminating search (where the items are scanned and counted one-by-one until the majority is decided). The two algorithms hold distinct implications for the involvement of cognitive control. The modeling results show that while both models are able to perform the task, the grouping search model fit the human data better than the self-terminating search model. An examination of the dynamics underlying model performance reveals how cognitive control might be instantiated in the brain for computing the majority function.

  8. Simulation of Gravity Currents Using VOF Model

    Institute of Scientific and Technical Information of China (English)

    邹建锋; 黄钰期; 应新亚; 任安禄

    2002-01-01

    By the Volume of Fluid (VOF) multiphase flow model two-dimensional gravity currents with three phases including air are numerically simulated in this article. The necessity of consideration of turbulence effect for high Reynolds numbers is demonstrated quantitatively by LES (the Large Eddy Simulation) turbulence model. The gravity currents are simulated for h ≠ H as well as h = H, where h is the depth of the gravity current before the release and H is the depth of the intruded fluid. Uprising of swell occurs when a current flows horizontally into another lighter one for h ≠ H. The problems under what condition the uprising of swell occurs and how long it takes are considered in this article. All the simulated results are in reasonable agreement with the experimental results available.

  9. Testing the Validity of a Cognitive Behavioral Model for Gambling Behavior.

    Science.gov (United States)

    Raylu, Namrata; Oei, Tian Po S; Loo, Jasmine M Y; Tsai, Jung-Shun

    2016-06-01

    Currently, cognitive behavioral therapies appear to be one of the most studied treatments for gambling problems and studies show it is effective in treating gambling problems. However, cognitive behavior models have not been widely tested using statistical means. Thus, the aim of this study was to test the validity of the pathways postulated in the cognitive behavioral theory of gambling behavior using structural equation modeling (AMOS 20). Several questionnaires assessing a range of gambling specific variables (e.g., gambling urges, cognitions and behaviors) and gambling correlates (e.g., psychological states, and coping styles) were distributed to 969 participants from the community. Results showed that negative psychological states (i.e., depression, anxiety and stress) only directly predicted gambling behavior, whereas gambling urges predicted gambling behavior directly as well as indirectly via gambling cognitions. Avoidance coping predicted gambling behavior only indirectly via gambling cognitions. Negative psychological states were significantly related to gambling cognitions as well as avoidance coping. In addition, significant gender differences were also found. The results provided confirmation for the validity of the pathways postulated in the cognitive behavioral theory of gambling behavior. It also highlighted the importance of gender differences in conceptualizing gambling behavior.

  10. Biological and artificial cognition: what can we learn about mechanisms by modelling physical cognition problems using artificial intelligence planning techniques?

    Science.gov (United States)

    Chappell, Jackie; Hawes, Nick

    2012-01-01

    Do we fully understand the structure of the problems we present to our subjects in experiments on animal cognition, and the information required to solve them? While we currently have a good understanding of the behavioural and neurobiological mechanisms underlying associative learning processes, we understand much less about the mechanisms underlying more complex forms of cognition in animals. In this study, we present a proposal for a new way of thinking about animal cognition experiments. We describe a process in which a physical cognition task domain can be decomposed into its component parts, and models constructed to represent both the causal events of the domain and the information available to the agent. We then implement a simple set of models, using the planning language MAPL within the MAPSIM simulation environment, and applying it to a puzzle tube task previously presented to orangutans. We discuss the results of the models and compare them with the results from the experiments with orangutans, describing the advantages of this approach, and the ways in which it could be extended. PMID:22927571

  11. Biological and artificial cognition: what can we learn about mechanisms by modelling physical cognition problems using artificial intelligence planning techniques?

    Science.gov (United States)

    Chappell, Jackie; Hawes, Nick

    2012-10-05

    Do we fully understand the structure of the problems we present to our subjects in experiments on animal cognition, and the information required to solve them? While we currently have a good understanding of the behavioural and neurobiological mechanisms underlying associative learning processes, we understand much less about the mechanisms underlying more complex forms of cognition in animals. In this study, we present a proposal for a new way of thinking about animal cognition experiments. We describe a process in which a physical cognition task domain can be decomposed into its component parts, and models constructed to represent both the causal events of the domain and the information available to the agent. We then implement a simple set of models, using the planning language MAPL within the MAPSIM simulation environment, and applying it to a puzzle tube task previously presented to orangutans. We discuss the results of the models and compare them with the results from the experiments with orangutans, describing the advantages of this approach, and the ways in which it could be extended.

  12. [Neuroethics of pharmaceutical cognitive enhancement: the first ten years: current problems and practical guiding principles].

    Science.gov (United States)

    Metzinger, T K

    2012-01-01

    An evaluating survey of the development of the neuroethics of pharmaceutical cognitive enhancement (PCE) during the last decade, focussing on the situation in Germany, has been undertaken. This article presents the most important conceptual problems, current substances and central ethical and legal issues. Very first guidelines and recommendations for policy-makers are formulated at the end of the text. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Transcranial alternating current stimulation: a review of the underlying mechanisms and modulation of cognitive processes

    OpenAIRE

    Herrmann, Christoph S; Rach, Stefan; Neuling, Toralf; Strüber, Daniel

    2013-01-01

    Brain oscillations of different frequencies have been associated with a variety of cognitive functions. Convincing evidence supporting those associations has been provided by studies using intracranial stimulation, pharmacological interventions and lesion studies. The emergence of novel non-invasive brain stimulation techniques like repetitive transcranial magnetic stimulation (rTMS) and transcranial alternating current stimulation (tACS) now allows to modulate brain oscillations directly. Pa...

  14. Modeling of cognitive impairment by disease duration in multiple sclerosis: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Anat Achiron

    Full Text Available BACKGROUND/AIMS: Large-scale population studies measuring rates and dynamics of cognitive decline in multiple sclerosis (MS are lacking. In the current cross-sectional study we evaluated the patterns of cognitive impairment in MS patients with disease duration of up to 30 years. METHODS: 1,500 patients with MS were assessed by a computerized cognitive battery measuring verbal and non-verbal memory, executive function, visual spatial perception, verbal function, attention, information processing speed and motor skills. Cognitive impairment was defined as below one standard deviation (SD and severe cognitive impairment as below 2SD for age and education matched healthy population norms. RESULTS: Cognitive performance in our cohort was poorer than healthy population norms. The most frequently impaired domains were information processing speed and executive function. MS patients with secondary-progressive disease course performed poorly compared with clinically isolated syndrome, relapsing-remitting and primary progressive MS patients. By the fifth year from disease onset, 20.9% of patients performed below the 1SD cutoff for impairment, p=0.005, and 6.0% performed below the 2SD cutoff for severe cognitive impairment, p=0.002. By 10 years from onset 29.3% and 9.0% of patients performed below the 1SD and 2SD cutoffs, respectively, p=0.0001. Regression modeling suggested that cognitive impairment may precede MS onset by 1.2 years. CONCLUSIONS: The rates of cognitive impairment in this large sample of MS patients were lower than previously reported and severe cognitive impairment was evident only in a relatively small group of patients. Cognitive impairment differed significantly from expected normal distribution only at five years from onset, suggesting the existence of a therapeutic window during which patients may benefit from interventions to maintain cognitive health.

  15. Modeling Educational Content: The Cognitive Approach of the PALO Language

    Directory of Open Access Journals (Sweden)

    M. Felisa Verdejo Maíllo

    2004-01-01

    Full Text Available This paper presents a reference framework to describe educational material. It introduces the PALO Language as a cognitive based approach to Educational Modeling Languages (EML. In accordance with recent trends for reusability and interoperability in Learning Technologies, EML constitutes an evolution of the current content-centered specifications of learning material, involving the description of learning processes and methods from a pedagogical and instructional perspective. The PALO Language, thus, provides a layer of abstraction for the description of learning material, including the description of learning activities, structure and scheduling. The framework makes use of domain and pedagogical ontologies as a reusable and maintainable way to represent and store instructional content, and to provide a pedagogical level of abstraction in the authoring process.

  16. Interactions between causal models, theories, and social cognitive development.

    Science.gov (United States)

    Sobel, David M; Buchanan, David W; Butterfield, Jesse; Jenkins, Odest Chadwicke

    2010-01-01

    We propose a model of social cognitive development based not on a single modeling framework or the hypothesis that a single model accounts for children's developing social cognition. Rather, we advocate a Causal Model approach (cf. Waldmann, 1996), in which models of social cognitive development take the same position as theories of social cognitive development, in that they generate novel empirical hypotheses. We describe this approach and present three examples across various aspects of social cognitive development. Our first example focuses on children's understanding of pretense and involves only considering assumptions made by a computational framework. The second example focuses on children's learning from "testimony". It uses a modeling framework based on Markov random fields as a computational description of a set of empirical phenomena, and then tests a prediction of that description. The third example considers infants' generalization of action learned from imitation. Here, we use a modified version of the Rational Model of Categorization to explain children's inferences. Taken together, these examples suggest that research in social cognitive development can be assisted by considering how computational modeling can lead researchers towards testing novel hypotheses.

  17. Current evidence for the use of coffee and caffeine to prevent age-related cognitive decline and Alzheimer's disease.

    Science.gov (United States)

    Carman, A J; Dacks, P A; Lane, R F; Shineman, D W; Fillit, H M

    2014-04-01

    Although nothing has been proven conclusively to protect against cognitive aging, Alzheimer's disease or related dementias, decades of research suggest that specific approaches including the consumption of coffee may be effective. While coffee and caffeine are known to enhance short-term memory and cognition, some limited research also suggests that long-term use may protect against cognitive decline or dementia. In vitro and pre-clinical animal models have identified plausible neuroprotective mechanisms of action of both caffeine and other bioactive components of coffee, though epidemiology has produced mixed results. Some studies suggest a protective association while others report no benefit. To our knowledge, no evidence has been gathered from randomized controlled trials. Although moderate consumption of caffeinated coffee is generally safe for healthy people, it may not be for everyone, since comorbidities and personal genetics influence potential benefits and risks. Future studies could include short-term clinical trials with biomarker outcomes to validate findings from pre-clinical models and improved epidemiological studies that incorporate more standardized methods of data collection and analysis. Given the enormous economic and emotional toll threatened by the current epidemic of Alzheimer's disease and other dementias, it is critically important to validate potential prevention strategies such as coffee and caffeine.

  18. Task-Specific Facilitation of Cognition by Anodal Transcranial Direct Current Stimulation of the Prefrontal Cortex.

    Science.gov (United States)

    Pope, Paul A; Brenton, Jonathan W; Miall, R Chris

    2015-11-01

    We previously speculated that depression of cerebellar excitability using cathodal transcranial direct current stimulation (tDCS) might release extra cognitive resources via the disinhibition of activity in prefrontal cortex. The objective of the present study was to investigate whether anodal tDCS over the prefrontal cortex could similarly improve performance when cognitive demands are high. Sixty-three right-handed participants in 3 separate groups performed the Paced Auditory Serial Addition Task (PASAT) and the more difficult Paced Auditory Serial Subtraction Task (PASST), before and after 20 min of anodal, cathodal, or sham stimulation over the left dorsolateral prefrontal cortex (DLPFC). Performance was assessed in terms of the accuracy, latency, and variability of correct verbal responses. All behavioral measures significantly improved for the PASST after anodal DLPFC stimulation, but not the PASAT. There were smaller practice effects after cathodal and sham stimulation. Subjective ratings of attention and mental fatigue were unchanged by tDCS over time. We conclude that anodal stimulation over the left DLPFC can selectively improve performance on a difficult cognitive task involving arithmetic processing, verbal working memory, and attention. This result might be achieved by focally improving executive functions and/or cognitive capacity when tasks are difficult, rather than by improving levels of arousal/alertness.

  19. Decision Making, Models of Mind, and the New Cognitive Science.

    Science.gov (United States)

    Evers, Colin W.

    1998-01-01

    Explores implications for understanding educational decision making from a cognitive science perspective. Examines three models of mind providing the methodological framework for decision-making studies. The "absent mind" embodies the behaviorist research tradition. The "functionalist mind" underwrites traditional cognitivism…

  20. Decision Making, Models of Mind, and the New Cognitive Science.

    Science.gov (United States)

    Evers, Colin W.

    1998-01-01

    Explores implications for understanding educational decision making from a cognitive science perspective. Examines three models of mind providing the methodological framework for decision-making studies. The "absent mind" embodies the behaviorist research tradition. The "functionalist mind" underwrites traditional cognitivism…

  1. Current Paranoid Thinking in Patients With Delusions: The Presence of Cognitive-Affective Biases

    Science.gov (United States)

    Freeman, Daniel

    2013-01-01

    Background: There has been renewed interest in the influence of affect on psychosis. Psychological research on persecutory delusions ascribes a prominent role to cognitive processes related to negative affect: anxiety leads to the anticipation of threat within paranoia; depressive negative ideas about the self create a sense of vulnerability in which paranoid thoughts flourish; and self-consciousness enhances feelings of the self as a target. The objective of this study was to examine such affective processes in relation to state paranoia in patients with delusions. Methods: 130 patients with delusions in the context of a nonaffective psychosis diagnosis (predominately schizophrenia) were assessed for contemporaneous levels of persecutory ideation on 5 visual analog scales. Measures were taken of anxiety, depression, threat anticipation, interpretation of ambiguity, self-focus, and negative ideas about the self. Results: Of the patients, 85% report paranoid thinking at testing. Symptoms of anxiety and depression were highly prevalent. Current paranoid thinking was associated with anxiety, depression, greater anticipation of threat events, negative interpretations of ambiguous events, a self-focused cognitive style, and negative ideas about the self. Conclusions: The study provides a clear demonstration that a range of emotion-related cognitive biases, each of which could plausibly maintain delusions, are associated with current paranoid thinking in patients with psychosis. We identified biases both in the contents of cognition and in the processing of information. Links between affect and psychosis are central to the understanding of schizophrenia. We conclude that treatment of emotional dysfunction should lead to reductions in current psychotic experiences. PMID:23223342

  2. Utilization-Based Modeling and Optimization for Cognitive Radio Networks

    Science.gov (United States)

    Liu, Yanbing; Huang, Jun; Liu, Zhangxiong

    The cognitive radio technique promises to manage and allocate the scarce radio spectrum in the highly varying and disparate modern environments. This paper considers a cognitive radio scenario composed of two queues for the primary (licensed) users and cognitive (unlicensed) users. According to the Markov process, the system state equations are derived and an optimization model for the system is proposed. Next, the system performance is evaluated by calculations which show the rationality of our system model. Furthermore, discussions among different parameters for the system are presented based on the experimental results.

  3. Relative and Absolute Fit Evaluation in Cognitive Diagnosis Modeling

    Science.gov (United States)

    Chen, Jinsong; de la Torre, Jimmy; Zhang, Zao

    2013-01-01

    As with any psychometric models, the validity of inferences from cognitive diagnosis models (CDMs) determines the extent to which these models can be useful. For inferences from CDMs to be valid, it is crucial that the fit of the model to the data is ascertained. Based on a simulation study, this study investigated the sensitivity of various fit…

  4. Behavioral modeling of Digitally Adjustable Current Amplifier

    Directory of Open Access Journals (Sweden)

    Josef Polak

    2015-03-01

    Full Text Available This article presents the digitally adjustable current amplifier (DACA and its analog behavioral model (ABM, which is suitable for both ideal and advanced analyses of the function block using DACA as active element. There are four levels of this model, each being suitable for simulation of a certain degree of electronic circuits design (e.g. filters, oscillators, generators. Each model is presented through a schematic wiring in the simulation program OrCAD, including a description of equations representing specific functions in the given level of the simulation model. The design of individual levels is always verified using PSpice simulations. The ABM model has been developed based on practically measured values of a number of DACA amplifier samples. The simulation results for proposed levels of the ABM model are shown and compared with the results of the real easurements of the active element DACA.

  5. Models of cognitive behavior in nuclear power plant personnel. A feasibility study: summary of results. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Woods, D.D.; Roth, E.M.; Hanes, L.F.

    1986-07-01

    This report summarizes the results of a feasibility study to determine if the current state of models of human cognitive activities can serve as the basis for improved techniques for predicting human error in nuclear power plants emergency operations. Based on the answer to this question, two subsequent phases of research are planned. Phase II is to develop a model of cognitive activities, and Phase III is to test the model. The feasibility study included an analysis of the cognitive activities that occur in emergency operations and an assessment of the modeling concepts/tools available to capture these cognitive activities. The results indicated that a symbolic processing (or artificial intelligence) model of cognitive activities in nuclear power plants is both desirable and feasible. This cognitive model can be built upon the computational framework provided by an existing artificial intelligence system for medical problem solving, called Caduceus. The resulting cognitive model will increase the capability to capture the human contribution to risk in probabilistic risk assessment studies. Volume 1 summarizes the major findings and conclusions of the study. Volume 2 provides a complete description of the methods and results, including a synthesis of the cognitive activities that occur during emergency operations, and a literature review on cognitive modeling relevant to nuclear power plants. 19 refs.

  6. Aspects of Piaget's cognitive developmental psychology and neurobiology of psychotic disorders - an integrative model.

    Science.gov (United States)

    Gebhardt, Stefan; Grant, Phillip; von Georgi, Richard; Huber, Martin T

    2008-09-01

    Psychological, neurobiological and neurodevelopmental approaches have frequently been used to provide pathogenic concepts on psychotic disorders. However, aspects of cognitive developmental psychology have hardly been considered in current models. Using a hypothesis-generating approach an integration of these concepts was conducted. According to Piaget (1896-1980), assimilation and accommodation as forms of maintenance and modification of cognitive schemata represent fundamental processes of the brain. In general, based on the perceived input stimuli, cognitive schemata are developed resulting in a conception of the world, the realistic validity and the actuality of which is still being controlled and modified by cognitive adjustment processes. In psychotic disorders, however, a disproportion of environmental demands and the ability to activate required neuronal adaptation processes occurs. We therefore hypothesize a failure of the adjustment of real and requested output patterns. As a consequence autonomous cognitive schemata are generated, which fail to adjust with reality resulting in psychotic symptomatology. Neurobiological, especially neuromodulatory and neuroplastic processes play a central role in these perceptive and cognitive processes. In conclusion, integration of cognitive developmental psychology into the existing pathogenic concepts of psychotic disorders leads to interesting insights into basic disease mechanisms and also guides future research in the cognitive neuroscience of such disorders.

  7. Cognitive model supported tactical training simulation

    NARCIS (Netherlands)

    Doesburg, W.A. van; Bosch, K. van den

    2005-01-01

    Simulation-based tactical training can be made more effective by using cognitive software agents to play key roles (e.g. team mate, adversaries, instructor). Due to the dynamic and complex nature of military tactics, it is hard to create agents that behave realistically and support the training lead

  8. Training tactical decision making using cognitive models

    NARCIS (Netherlands)

    Bosch, K. van den; Doesburg, W.A. van

    2005-01-01

    Simulation-based tactical training can be made more effective by using cognitive software agents to play key roles (e.g. team mates, adversaries). For successful use in training, agents should show tactically representative behavior that support trainees in achieving the learning objectives. For a t

  9. Dynamic Cognitive Tracing: Towards Unified Discovery of Student and Cognitive Models

    Science.gov (United States)

    Gonzalez-Brenes, Jose P.; Mostow, Jack

    2012-01-01

    This work describes a unified approach to two problems previously addressed separately in Intelligent Tutoring Systems: (i) Cognitive Modeling, which factorizes problem solving steps into the latent set of skills required to perform them; and (ii) Student Modeling, which infers students' learning by observing student performance. The practical…

  10. [Non-invasive brain stimulation in neurology : Transcranial direct current stimulation to enhance cognitive functioning].

    Science.gov (United States)

    Antonenko, D; Flöel, A

    2016-08-01

    Transcranial direct current stimulation (tDCS) has been successfully used in neuroscientific research to modulate cognitive functions. Recent studies suggested that improvement of behavioral performance is associated with tDCS-induced modulation of neuronal activity and connectivity. Thus, tDCS may also represent a promising tool for reconstitution of cognitive functions in the context of memory decline related to Alzheimer's disease or aphasia following stroke; however, evidence from randomized sham-controlled clinical trials is still scarce. Initial results of tDCS-induced behavioral improvement in patients with Alzheimer's dementia and its precursors indicated that an intense memory training combined with tDCS may be effective. Early interventions in the stage of mild cognitive impairment could be crucial but further evidence is needed to substantiate this. In patients with aphasia following stroke tDCS was applied to the left and right hemispheres, with varying results depending on the severity of the symptoms and polarity of the stimulation. Patients with mild aphasia can benefit from tDCS of the language dominant hemisphere while in patients with severe aphasia tDCS of right hemispheric homologous brain language areas may be particularly relevant. Moreover, recent studies suggested that an intervention in the subacute phase of aphasia could be most promising. In summary, tDCS could provide the exciting possibility to reconstitute cognitive functions in patients with neurological disorders. Future studies have to elucidate whether tDCS can be used in the clinical routine to prevent further cognitive decline in neurodegenerative diseases and whether beneficial effects from experimental studies translate into long-term improvement in activities of daily life.

  11. A generalized and parameterized interference model for cognitive radio networks

    KAUST Repository

    Mahmood, Nurul Huda

    2011-06-01

    For meaningful co-existence of cognitive radios with primary system, it is imperative that the cognitive radio system is aware of how much interference it generates at the primary receivers. This can be done through statistical modeling of the interference as perceived at the primary receivers. In this work, we propose a generalized model for the interference generated by a cognitive radio network, in the presence of small and large scale fading, at a primary receiver located at the origin. We then demonstrate how this model can be used to estimate the impact of cognitive radio transmission on the primary receiver in terms of different outage probabilities. Finally, our analytical findings are validated through some selected computer-based simulations. © 2011 IEEE.

  12. Dynamic statistical models of biological cognition: insights from communications theory

    Science.gov (United States)

    Wallace, Rodrick

    2014-10-01

    Maturana's cognitive perspective on the living state, Dretske's insight on how information theory constrains cognition, the Atlan/Cohen cognitive paradigm, and models of intelligence without representation, permit construction of a spectrum of dynamic necessary conditions statistical models of signal transduction, regulation, and metabolism at and across the many scales and levels of organisation of an organism and its context. Nonequilibrium critical phenomena analogous to physical phase transitions, driven by crosstalk, will be ubiquitous, representing not only signal switching, but the recruitment of underlying cognitive modules into tunable dynamic coalitions that address changing patterns of need and opportunity at all scales and levels of organisation. The models proposed here, while certainly providing much conceptual insight, should be most useful in the analysis of empirical data, much as are fitted regression equations.

  13. Pharmacological approaches to improving cognitive function in Down syndrome: current status and considerations

    Directory of Open Access Journals (Sweden)

    Gardiner KJ

    2014-12-01

    Full Text Available Katheleen J Gardiner Linda Crnic Institute for Down Syndrome, Department of Pediatrics, Department of Biochemistry and Molecular Genetics, Human Medical Genetics and Genomics Program, Neuroscience Program, University of Colorado School of Medicine, Aurora, CO, USA Abstract: Down syndrome (DS, also known as trisomy 21, is the most common genetic cause of intellectual disability (ID. Although ID can be mild, the average intelligence quotient is in the range of 40–50. All individuals with DS will also develop the neuropathology of Alzheimer’s disease (AD by the age of 30–40 years, and approximately half will display an AD-like dementia by the age of 60 years. DS is caused by an extra copy of the long arm of human chromosome 21 (Hsa21 and the consequent elevated levels of expression, due to dosage, of trisomic genes. Despite a worldwide incidence of one in 700–1,000 live births, there are currently no pharmacological treatments available for ID or AD in DS. However, over the last several years, very promising results have been obtained with a mouse model of DS, the Ts65Dn. A diverse array of drugs has been shown to rescue, or partially rescue, DS-relevant deficits in learning and memory and abnormalities in cellular and electrophysiological features seen in the Ts65Dn. These results suggest that some level of amelioration or prevention of cognitive deficits in people with DS may be possible. Here, we review information from the preclinical evaluations in the Ts65Dn, how drugs were selected, how efficacy was judged, and how outcomes differ, or not, among studies. We also summarize the current state of human clinical trials for ID and AD in DS. Lastly, we describe the genetic limitations of the Ts65Dn as a model of DS, and in the preclinical testing of pharmacotherapeutics, and suggest additional targets to be considered for potential pharmacotherapies. Keywords: Ts65Dn, pharmacotherapy, clinical trials, Hsa21

  14. A cognitive map model based on spatial and goal-oriented mental exploration in rodents.

    Science.gov (United States)

    Zhu, Qing; Wang, Rubin; Wang, Ziyin

    2013-11-01

    The rodent hippocampus has been used to represent the spatial environment as a cognitive map. Classical theories suggest that the cognitive map is a consequence of assignment of different spatial regions to variant cell populations in the framework of rate coding. The current study constructs a novel computational neural model of the cognitive map based on firing rate coding, as widely appears in associative memory, thus providing an explanation for formation and function of the two types of cognitive maps: the spatial vector map, responsible for self localization and simultaneous updating of detailed information; and the goal-oriented vector map, important in route finding. A proposed intermediate between these two map types was constructed by combining the spatial vector and goal-orientation maps to form an effective and efficient path finding mechanism. Application of such novel cognitive map based path finding methods to a mental exploration model was explored. With adaptation as a driving force, the basic knowledge of the location relationships in the spatial cognitive map was reformed and sent to the goal-oriented cognitive map, thus solving a series of new path problems through mental exploration. This method allows for rapid identification of suitable paths under variant conditions, thus providing a simpler and safer resource for path finding. Additionally, this method also provides an improved basis for potential robotic path finding applications.

  15. Defining and Comparing the Reading Comprehension Construct: A Cognitive-Psychometric Modeling Approach

    Science.gov (United States)

    Svetina, Dubravka; Gorin, Joanna S.; Tatsuoka, Kikumi K.

    2011-01-01

    As a construct definition, the current study develops a cognitive model describing the knowledge, skills, and abilities measured by critical reading test items on a high-stakes assessment used for selection decisions in the United States. Additionally, in order to establish generalizability of the construct meaning to other similarly structured…

  16. Modeling the effects of noninvasive transcranial brain stimulation at the biophysical, network, and cognitive level.

    Science.gov (United States)

    Hartwigsen, Gesa; Bergmann, Til Ole; Herz, Damian Marc; Angstmann, Steffen; Karabanov, Anke; Raffin, Estelle; Thielscher, Axel; Siebner, Hartwig Roman

    2015-01-01

    Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how these approaches advance the scientific potential of NTBS as an interventional tool in cognitive neuroscience. (i) Leveraging the anatomical information provided by structural imaging, the electric field distribution in the brain can be modeled and simulated. Biophysical modeling approaches generate testable predictions regarding the impact of interindividual variations in cortical anatomy on the injected electric fields or the influence of the orientation of current flow on the physiological stimulation effects. (ii) Functional brain mapping of the spatiotemporal neural dynamics during cognitive tasks can be used to construct causal network models. These models can identify spatiotemporal changes in effective connectivity during distinct cognitive states and allow for examining how effective connectivity is shaped by NTBS. (iii) Modeling the NTBS effects based on neuroimaging can be complemented by behavior-based cognitive models that exploit variations in task performance. For instance, NTBS-induced changes in response speed and accuracy can be explicitly modeled in a cognitive framework accounting for the speed-accuracy trade-off. This enables to dissociate between behavioral NTBS effects that emerge in the context of rapid automatic responses or in the context of slow deliberate responses. We argue that these complementary modeling approaches facilitate the use of NTBS as a means of dissecting the causal architecture of cognitive systems of the human brain.

  17. Testing Cognitive and Emotion-Focused Models of Worry in Black and White Samples.

    Science.gov (United States)

    Kertz, Sarah J; Bakhti, Rinad; Stevens, Kimberly T; Curewitz, Alana

    2015-01-01

    Several models have been proposed to conceptualize worry. Broadly, the models can be classified as cognitive (including the Avoidance Model, the Intolerance of Uncertainty Model, and the Metacognitive Model) and emotion-focused (including Emotion Dysregulation and Acceptance-Based models). Although these models have received strong empirical investigation in primarily non-Hispanic White samples, no known study has examined the applicability to racial and ethnic minority groups. The current study compared the proportion of variance explained by cognitive and emotion-focused models of worry in White and Black samples. Results indicated that cognitive and emotion-focused models significantly predicted worry in both Black and White samples. However, the overall amount of variance in worry explained by the models was less for Black samples. Specifically, controlling for gender, the cognitive models explained 53% of the variance in worry in the White sample compared with 19% in the Black sample. Similarly, the emotion-focused models explained 34% of the variance in worry in the White sample but only 13% in the Black sample. These findings suggest that well-established conceptual frameworks for worry failed to explain the bulk of the variance in worry in Black samples, leaving much unknown. Additional research is needed to identify key variables that may further explain worry in ethnic minority samples.

  18. Cognitive performance modeling based on general systems performance theory.

    Science.gov (United States)

    Kondraske, George V

    2010-01-01

    General Systems Performance Theory (GSPT) was initially motivated by problems associated with quantifying different aspects of human performance. It has proved to be invaluable for measurement development and understanding quantitative relationships between human subsystem capacities and performance in complex tasks. It is now desired to bring focus to the application of GSPT to modeling of cognitive system performance. Previous studies involving two complex tasks (i.e., driving and performing laparoscopic surgery) and incorporating measures that are clearly related to cognitive performance (information processing speed and short-term memory capacity) were revisited. A GSPT-derived method of task analysis and performance prediction termed Nonlinear Causal Resource Analysis (NCRA) was employed to determine the demand on basic cognitive performance resources required to support different levels of complex task performance. This approach is presented as a means to determine a cognitive workload profile and the subsequent computation of a single number measure of cognitive workload (CW). Computation of CW may be a viable alternative to measuring it. Various possible "more basic" performance resources that contribute to cognitive system performance are discussed. It is concluded from this preliminary exploration that a GSPT-based approach can contribute to defining cognitive performance models that are useful for both individual subjects and specific groups (e.g., military pilots).

  19. A cognitively plausible model for grammar induction

    Directory of Open Access Journals (Sweden)

    Roni Katzir

    2015-01-01

    Full Text Available This paper aims to bring theoretical linguistics and cognition-general theories of learning into closer contact. I argue that linguists' notions of rich UGs are well-founded, but that cognition-general learning approaches are viable as well and that the two can and should co-exist and support each other. Specifically, I use the observation that any theory of UG provides a learning criterion -- the total memory space used to store a grammar and its encoding of the input -- that supports learning according to the principle of Minimum Description-Length. This mapping from UGs to learners maintains a minimal ontological commitment: the learner for a particular UG uses only what is already required to account for linguistic competence in adults. I suggest that such learners should be our null hypothesis regarding the child's learning mechanism, and that furthermore, the mapping from theories of UG to learners provides a framework for comparing theories of UG.

  20. Schizophrenia: A Cognitive Model and Its Implications for Psychological Intervention.

    Science.gov (United States)

    Hemsley, David R.

    1996-01-01

    Proposes a cognitive model of schizophrenia stating that schizophrenic behavior is caused by a disturbance in sensory input and stored material integration. Cites research to support this model. Outlines the manner in which a disturbance in sensory input integration relates to schizophrenic symptoms and discusses the model's relevance for…

  1. Cognitive interference modeling with applications in power and admission control

    KAUST Repository

    Mahmood, Nurul Huda

    2012-10-01

    One of the key design challenges in a cognitive radio network is controlling the interference generated at coexisting primary receivers. In order to design efficient cognitive radio systems and to minimize their unwanted consequences, it is therefore necessary to effectively control the secondary interference at the primary receivers. In this paper, a generalized framework for the interference analysis of a cognitive radio network where the different secondary transmitters may transmit with different powers and transmission probabilities, is presented and various applications of this interference model are demonstrated. The findings of the analytical performance analyses are confirmed through selected computer-based Monte-Carlo simulations. © 2012 IEEE.

  2. On a Cognitive Model of Semiosis

    Directory of Open Access Journals (Sweden)

    Konderak Piotr

    2015-03-01

    Full Text Available What is the class of possible semiotic systems? What kinds of systems could count as such systems? The human mind is naturally considered the prototypical semiotic system. During years of research in semiotics the class has been broadened to include i.e. living systems (Zlatev, 2002 like animals, or even plants (Krampen, 1992. It is suggested in the literature on artificial intelligence that artificial agents are typical examples of symbol-processing entities. It also seems that (at least some semiotic processes are in fact cognitive processes. In consequence, it is natural to ask the question about the relation between semiotic studies and research on artificial cognitive systems within cognitive science. Consequently, my main question concerns the problem of inclusion or exclusion from the semiotic spectrum at least some artificial (computational systems. I would like to consider some arguments against the possibility of artificial semiotic systems and I will try to repeal them. Then I will present an existing natural-language using agent of the SNePS system and interpret it in terms of Peircean theory of signs. I would like also to show that some properties of semiotic systems in Peircean sense could be also found in a discussed artificial system. Finally, I will have some remarks on the status of semiotics in general.

  3. ARCHITECTURES AND ALGORITHMS FOR COGNITIVE NETWORKS ENABLED BY QUALITATIVE MODELS

    DEFF Research Database (Denmark)

    Balamuralidhar, P.

    2013-01-01

    the qualitative models in a cognitive engine. Further I use the methodology in multiple functional scenarios of cognitive networks including self- optimization and self- monitoring. In the case of self-optimization, I integrate principles from monotonicity analysis to evaluate and enhance qualitative models......Complexity of communication networks is ever increasing and getting complicated by their heterogeneity and dynamism. Traditional techniques are facing challenges in network performance management. Cognitive networking is an emerging paradigm to make networks more intelligent, thereby overcoming...... traditional limitations and potentially achieving better performance. The vision is that, networks should be able to monitor themselves, reason upon changes in self and environment, act towards the achievement of specific goals and learn from experience. The concept of a Cognitive Engine (CE) supporting...

  4. The multi-component model of working memory: explorations in experimental cognitive psychology.

    Science.gov (United States)

    Repovs, G; Baddeley, A

    2006-04-28

    There are a number of ways one can hope to describe and explain cognitive abilities, each of them contributing a unique and valuable perspective. Cognitive psychology tries to develop and test functional accounts of cognitive systems that explain the capacities and properties of cognitive abilities as revealed by empirical data gathered by a range of behavioral experimental paradigms. Much of the research in the cognitive psychology of working memory has been strongly influenced by the multi-component model of working memory [Baddeley AD, Hitch GJ (1974) Working memory. In: Recent advances in learning and motivation, Vol. 8 (Bower GA, ed), pp 47-90. New York: Academic Press; Baddeley AD (1986) Working memory. Oxford, UK: Clarendon Press; Baddeley A. Working memory: Thought and action. Oxford: Oxford University Press, in press]. By expanding the notion of a passive short-term memory to an active system that provides the basis for complex cognitive abilities, the model has opened up numerous questions and new lines of research. In this paper we present the current revision of the multi-component model that encompasses a central executive, two unimodal storage systems: a phonological loop and a visuospatial sketchpad, and a further component, a multimodal store capable of integrating information into unitary episodic representations, termed episodic buffer. We review recent empirical data within experimental cognitive psychology that has shaped the development of the multicomponent model and the understanding of the capacities and properties of working memory. Research based largely on dual-task experimental designs and on neuropsychological evidence has yielded valuable information about the fractionation of working memory into independent stores and processes, the nature of representations in individual stores, the mechanisms of their maintenance and manipulation, the way the components of working memory relate to each other, and the role they play in other

  5. The implicit possibility of dualism in quantum probabilistic cognitive modeling.

    Science.gov (United States)

    Mender, Donald

    2013-06-01

    Pothos & Busemeyer (P&B) argue convincingly that quantum probability offers an improvement over classical Bayesian probability in modeling the empirical data of cognitive science. However, a weakness related to restrictions on the dimensionality of incompatible physical observables flows from the authors' "agnosticism" regarding quantum processes in neural substrates underlying cognition. Addressing this problem will require either future research findings validating quantum neurophysics or theoretical expansion of the uncertainty principle as a new, neurocognitively contextualized, "local" symmetry.

  6. Exploring the cognitive and motor functions of the basal ganglia: an integrative review of computational cognitive neuroscience models

    OpenAIRE

    Sebastien eHelie; Srinivasa eChakravarthy; Ahmed A. Moustafa

    2013-01-01

    Many computational models of the basal ganglia have been proposed over the past twenty-five years. While computational neuroscience models have focused on closely matching the neurobiology of the basal ganglia, computational cognitive neuroscience models have focused on how the basal ganglia can be used to implement cognitive and motor functions. This review article focuses on computational cognitive neuroscience models of the basal ganglia and how they use the neuroanatomy of the basal gangl...

  7. Cognitive improvement by activation of alpha7 nicotinic acetylcholine receptors: from animal models to human pathophysiology

    DEFF Research Database (Denmark)

    Thomsen, Morten S; Hansen, Henrik H; Timmerman, Daniel B

    2010-01-01

    Agonists and positive allosteric modulators of the alpha(7) nicotinic acetylcholine receptor (nAChR) are currently being developed for the treatment of cognitive disturbances in patients with schizophrenia or Alzheimer's disease. This review describes the neurobiological properties of the alpha n......AChR and the cognitive effects of alpha(7) nAChR activation, focusing on the translational aspects in the development of these drugs. The functional properties and anatomical localization of the alpha(7) nAChR makes it well suited to modulate cognitive function. Accordingly, systemic administration of alpha(7) n......AChR agonists improves learning, memory, and attentional function in variety of animal models, and pro-cognitive effects of alpha(7) nAChR agonists have recently been demonstrated in patients with schizophrenia or Alzheimer's disease. The alpha(7) nAChR desensitizes rapidly in vitro, and this has been a major...

  8. Value and Efficacy of Transcranial Direct Current Stimulation in the Cognitive Rehabilitation: A Critical Review Since 2000.

    Science.gov (United States)

    Cappon, Davide; Jahanshahi, Marjan; Bisiacchi, Patrizia

    2016-01-01

    Non-invasive brain stimulation techniques, including transcranial direct current stimulation (t-DCS) have been used in the rehabilitation of cognitive function in a spectrum of neurological disorders. The present review outlines methodological communalities and differences of t-DCS procedures in neurocognitive rehabilitation. We consider the efficacy of tDCS for the management of specific cognitive deficits in four main neurological disorders by providing a critical analysis of recent studies that have used t-DCS to improve cognition in patients with Parkinson's Disease, Alzheimer's Disease, Hemi-spatial Neglect, and Aphasia. The evidence from this innovative approach to cognitive rehabilitation suggests that tDCS can influence cognition. However, the results show a high variability between studies both in terms of the methodological approach adopted and the cognitive functions targeted. The review also focuses both on methodological issues such as technical aspects of the stimulation (electrode position and dimension; current intensity; duration of protocol) and on the inclusion of appropriate assessment tools for cognition. A further aspect considered is the optimal timing for administration of tDCS: before, during or after cognitive rehabilitation. We conclude that more studies using common methodology are needed to gain a better understanding of the efficacy of tDCS as a new tool for rehabilitation of cognitive disorders in a range of neurological disorders.

  9. Value and efficacy of transcranial direct current stimulation in the cognitive rehabilitation : A critical review since 2000.

    Directory of Open Access Journals (Sweden)

    Davide eCappon

    2016-04-01

    Full Text Available Non-invasive brain stimulation techniques, including transcranial direct current stimulation (t-DCS have been used in the rehabilitation of cognitive function in a spectrum of neurological disorders. The present review outlines methodological communalities and differences of t-DCS procedures in neurocognitive rehabilitation. We consider the efficacy of tDCS for the management of specific cognitive deficits in four main neurological disorders by providing a critical analysis of recent studies that have used t-DCS to improve cognition in patients with Parkinson’s Disease, Alzheimer’s Disease, Hemi-spatial Neglect and Aphasia. The evidence from this innovative approach to cognitive rehabilitation suggests that tDCS can influence cognition. However, the results show a high variability between studies both in terms of the methodological approach adopted and the cognitive functions targeted. The review also focuses both on methodological issues such as technical aspects of the stimulation (electrode position and dimension; current intensity; duration of protocol and on the inclusion of appropriate assessment tools for cognition. A further aspect considered is the optimal timing for administration of tDCS: before, during or after cognitive rehabilitation. We conclude that more studies using common methodology are needed to gain a better understanding of the efficacy of tDCS as a new tool for rehabilitation of cognitive disorders in a range of neurological disorders.

  10. Exploring EFL Teachers’ Cognitive Models Through Metaphor Analysis

    Directory of Open Access Journals (Sweden)

    Hui Xiong

    2015-10-01

    Full Text Available This study aims to investigate how a group of Chinese university teachers developed their cognitive models by using “English as a Foreign Language (EFL teachers” metaphors. The research method includes an open-ended questionnaire, a checklist questionnaire, and verbal reports. The goal for this research is twofold. First, we will present those metaphors we believe to be the most frequently used or most central in shaping the thoughts or ideas they have had for EFL teaching and learning. Second, we will provide a description of their internal process of developing cognitive models, as well as factors that could account for such models. The findings showed that (a most of us had three ways of understanding EFL teachers in terms of the educational journey metaphor, the educational building metaphor, and the educational conduit metaphor; (b we used such a cluster of converging cognitive models as the instructor model, the transmitter model, and the builder model to construct definitions for EFL teachers, with the instructor model as a central model; and (c metaphor can actually serve as a useful, effective, and analytic tool for making us aware of the cognitive model underlying our conceptual framework.

  11. Cognitive Modeling for Agent-Based Simulation of Child Maltreatment

    Science.gov (United States)

    Hu, Xiaolin; Puddy, Richard

    This paper extends previous work to develop cognitive modeling for agent-based simulation of child maltreatment (CM). The developed model is inspired from parental efficacy, parenting stress, and the theory of planned behavior. It provides an explanatory, process-oriented model of CM and incorporates causality relationship and feedback loops from different factors in the social ecology in order for simulating the dynamics of CM. We describe the model and present simulation results to demonstrate the features of this model.

  12. A cognitive computational model inspired by the immune system response.

    Science.gov (United States)

    Abdo Abd Al-Hady, Mohamed; Badr, Amr Ahmed; Mostafa, Mostafa Abd Al-Azim

    2014-01-01

    The immune system has a cognitive ability to differentiate between healthy and unhealthy cells. The immune system response (ISR) is stimulated by a disorder in the temporary fuzzy state that is oscillating between the healthy and unhealthy states. However, modeling the immune system is an enormous challenge; the paper introduces an extensive summary of how the immune system response functions, as an overview of a complex topic, to present the immune system as a cognitive intelligent agent. The homogeneity and perfection of the natural immune system have been always standing out as the sought-after model we attempted to imitate while building our proposed model of cognitive architecture. The paper divides the ISR into four logical phases: setting a computational architectural diagram for each phase, proceeding from functional perspectives (input, process, and output), and their consequences. The proposed architecture components are defined by matching biological operations with computational functions and hence with the framework of the paper. On the other hand, the architecture focuses on the interoperability of main theoretical immunological perspectives (classic, cognitive, and danger theory), as related to computer science terminologies. The paper presents a descriptive model of immune system, to figure out the nature of response, deemed to be intrinsic for building a hybrid computational model based on a cognitive intelligent agent perspective and inspired by the natural biology. To that end, this paper highlights the ISR phases as applied to a case study on hepatitis C virus, meanwhile illustrating our proposed architecture perspective.

  13. The Cognitive Complexity in Modelling the Group Decision Process

    Directory of Open Access Journals (Sweden)

    Barna Iantovics

    2010-06-01

    Full Text Available The paper investigates for some basic contextual factors (such
    us the problem complexity, the users' creativity and the problem space complexity the cognitive complexity associated with modelling the group decision processes (GDP in e-meetings. The analysis is done by conducting a socio-simulation experiment for an envisioned collaborative software tool that acts as a stigmergic environment for modelling the GDP. The simulation results revels some interesting design guidelines for engineering some contextual functionalities that minimize the cognitive complexity associated with modelling the GDP.

  14. Neural and Cognitive Modeling with Networks of Leaky Integrator Units

    Science.gov (United States)

    Graben, Peter beim; Liebscher, Thomas; Kurths, Jürgen

    After reviewing several physiological findings on oscillations in the electroencephalogram (EEG) and their possible explanations by dynamical modeling, we present neural networks consisting of leaky integrator units as a universal paradigm for neural and cognitive modeling. In contrast to standard recurrent neural networks, leaky integrator units are described by ordinary differential equations living in continuous time. We present an algorithm to train the temporal behavior of leaky integrator networks by generalized back-propagation and discuss their physiological relevance. Eventually, we show how leaky integrator units can be used to build oscillators that may serve as models of brain oscillations and cognitive processes.

  15. Computational model of sustained acceleration effects on human cognitive performance.

    Science.gov (United States)

    McKinlly, Richard A; Gallimore, Jennie J

    2013-08-01

    Extreme acceleration maneuvers encountered in modern agile fighter aircraft can wreak havoc on human physiology, thereby significantly influencing cognitive task performance. As oxygen content declines under acceleration stress, the activity of high order cortical tissue reduces to ensure sufficient metabolic resources are available for critical life-sustaining autonomic functions. Consequently, cognitive abilities reliant on these affected areas suffer significant performance degradations. The goal was to develop and validate a model capable of predicting human cognitive performance under acceleration stress. Development began with creation of a proportional control cardiovascular model that produced predictions of several hemodynamic parameters, including eye-level blood pressure and regional cerebral oxygen saturation (rSo2). An algorithm was derived to relate changes in rSo2 within specific brain structures to performance on cognitive tasks that require engagement of different brain areas. Data from the "precision timing" experiment were then used to validate the model predicting cognitive performance as a function of G(z) profile. The following are value ranges. Results showed high agreement between the measured and predicted values for the rSo2 (correlation coefficient: 0.7483-0.8687; linear best-fit slope: 0.5760-0.9484; mean percent error: 0.75-3.33) and cognitive performance models (motion inference task--correlation coefficient: 0.7103-0.9451; linear best-fit slope: 0.7416-0.9144; mean percent error: 6.35-38.21; precision timing task--correlation coefficient: 0.6856-0.9726; linear best-fit slope: 0.5795-1.027; mean percent error: 6.30-17.28). The evidence suggests that the model is capable of accurately predicting cognitive performance of simplistic tasks under high acceleration stress.

  16. A COGNITIVE APPROACH TO CORPORATE GOVERNANCE: A VISUALIZATION TEST OF MENTAL MODELS WITH THE COGNITIVE MAPPING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Garoui NASSREDDINE

    2012-01-01

    Full Text Available The idea of this paper is to determine the mental models of actors in the fi rm with respect to the cognitive approach of corporate governance. The paper takes a corporate governance perspective, discusses mental models and uses the cognitive map to view the diagrams showing the ways of thinking and the conceptualization of the cognitive approach. In addition, it employs a cognitive mapping technique. Returning to the systematic exploration of grids for each actor, it concludes that there is a balance of concepts expressing their cognitive orientation.

  17. Benchmarking an Unstructured-Grid Model for Tsunami Current Modeling

    Science.gov (United States)

    Zhang, Yinglong J.; Priest, George; Allan, Jonathan; Stimely, Laura

    2016-12-01

    We present model results derived from a tsunami current benchmarking workshop held by the NTHMP (National Tsunami Hazard Mitigation Program) in February 2015. Modeling was undertaken using our own 3D unstructured-grid model that has been previously certified by the NTHMP for tsunami inundation. Results for two benchmark tests are described here, including: (1) vortex structure in the wake of a submerged shoal and (2) impact of tsunami waves on Hilo Harbor in the 2011 Tohoku event. The modeled current velocities are compared with available lab and field data. We demonstrate that the model is able to accurately capture the velocity field in the two benchmark tests; in particular, the 3D model gives a much more accurate wake structure than the 2D model for the first test, with the root-mean-square error and mean bias no more than 2 cm s-1 and 8 mm s-1, respectively, for the modeled velocity.

  18. Model of music cognition and amusia.

    Science.gov (United States)

    García-Casares, N; Berthier Torres, M L; Froudist Walsh, S; González-Santos, P

    2013-04-01

    The study of the neural networks involved in music processing has received less attention than work researching the brain's language networks. For the last two decades there has been a growing interest in discovering the functional mechanisms of the musical brain and understanding those disorders in which brain regions linked with perception and production of music are damaged. Congenital and acquired musical deficits in their various forms (perception, execution, music-memory) are grouped together under the generic term amusia. In this selective review we present the "cutting edge" studies on the cognitive and neural processes implicated in music and the various forms of amusia. Musical processing requires a large cortico-subcortical network which is distributed throughout both cerebral hemispheres and the cerebellum. The analysis of healthy subjects using functional neuroimaging and examination of selective deficits (e.g., tone, rhythm, timbre, melodic contours) in patients will improve our knowledge of the mechanisms involved in musical processing and the latter's relationship with other cognitive processes. Copyright © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  19. Cognitive behavioral therapy in anxiety disorders: current state of the evidence.

    Science.gov (United States)

    Otte, Christian

    2011-01-01

    A plethora of studies have examined the efficacy and effectiveness of cognitive-behavioral therapy (CBT) for adult anxiety disorders. In recent years, several meta-analyses have been conducted to quantitatively review the evidence of CBT for anxiety disorders, each using different inclusion criteria for studies, such as use of control conditions or type of study environment. This review aims to summarize and to discuss the current state of the evidence regarding CBT treatment for panic disorder, generalized anxiety disorder, social anxiety disorder, obsessive-compulsive disorder, and post-traumatic stress disorder. Overall, CBT demonstrates both efficacy in randomized controlled trials and effectiveness in naturalistic settings in the treatment of adult anxiety disorders. However, due to methodological issues, the magnitude of effect is currently difficult to estimate. In conclusion, CBT appears to be both efficacious and effective in the treatment of anxiety disorders, but more high-quality studies are needed to better estimate the magnitude of the effect.

  20. Human strategic reasoning in dynamic games: Experiments, logics, cognitive models

    NARCIS (Netherlands)

    Ghosh, Sujata; Halder, Tamoghna; Sharma, Khyati; Verbrugge, Rineke

    2015-01-01

    © Springer-Verlag Berlin Heidelberg 2015.This article provides a three-way interaction between experiments, logic and cognitive modelling so as to bring out a shared perspective among these diverse areas, aiming towards better understanding and better modelling of human strategic reasoning in

  1. Modeling Epistemic and Ontological Cognition: Philosophical Perspectives and Methodological Directions

    Science.gov (United States)

    Greene, Jeffrey A.; Azevedo, Roger A.; Torney-Purta, Judith

    2008-01-01

    We propose an integration of aspects of several developmental and systems of beliefs models of personal epistemology. Qualitatively different positions, including realism, dogmatism, skepticism, and rationalism, are characterized according to individuals' beliefs across three dimensions in a model of epistemic and ontological cognition. This model…

  2. Human strategic reasoning in dynamic games: Experiments, logics, cognitive models

    NARCIS (Netherlands)

    Ghosh, Sujata; Halder, Tamoghna; Sharma, Khyati; Verbrugge, Rineke

    2015-01-01

    © Springer-Verlag Berlin Heidelberg 2015.This article provides a three-way interaction between experiments, logic and cognitive modelling so as to bring out a shared perspective among these diverse areas, aiming towards better understanding and better modelling of human strategic reasoning in dynami

  3. Designing e-learning cognitively: TSOI Hybrid Learning Model

    Directory of Open Access Journals (Sweden)

    Mun Fie Tsoi

    2008-08-01

    Full Text Available Research on learning has proposed various models for learning. However, generally, there has been an inadequate research of the application of these models for learning for example the Kolb’s experiential learning cycle or the Jarvis’s model of reflection and learning to the development of e-learning materials. This is more so especially due to lack of effective yet practical design model for designing interactive e-learning materials. Having this in mind, the TSOI Hybrid Learning Model can be used as a pedagogic model for the cognitive design of e-learning. This Model represents learning as a cyclical cognitive process. A major feature is to promote active cognitive processing in the learner for meaningful learning proceeding from inductive to deductive. Design specificity in science and chemistry education is illustrated in terms of instructional storyboarding and the research-based e-learning product developed. Learners’ cognitive abilities will be addressed as part of the research data collected.

  4. Potential of Cognitive Computing and Cognitive Systems

    Science.gov (United States)

    Noor, Ahmed K.

    2014-11-01

    Cognitive computing and cognitive technologies are game changers for future engineering systems, as well as for engineering practice and training. They are major drivers for knowledge automation work, and the creation of cognitive products with higher levels of intelligence than current smart products. This paper gives a brief review of cognitive computing and some of the cognitive engineering systems activities. The potential of cognitive technologies is outlined, along with a brief description of future cognitive environments, incorporating cognitive assistants - specialized proactive intelligent software agents designed to follow and interact with humans and other cognitive assistants across the environments. The cognitive assistants engage, individually or collectively, with humans through a combination of adaptive multimodal interfaces, and advanced visualization and navigation techniques. The realization of future cognitive environments requires the development of a cognitive innovation ecosystem for the engineering workforce. The continuously expanding major components of the ecosystem include integrated knowledge discovery and exploitation facilities (incorporating predictive and prescriptive big data analytics); novel cognitive modeling and visual simulation facilities; cognitive multimodal interfaces; and cognitive mobile and wearable devices. The ecosystem will provide timely, engaging, personalized / collaborative, learning and effective decision making. It will stimulate creativity and innovation, and prepare the participants to work in future cognitive enterprises and develop new cognitive products of increasing complexity. http://www.aee.odu.edu/cognitivecomp

  5. A study of model bivalve siphonal currents

    Science.gov (United States)

    Monismith, Stephen G.; Koseff, Jeffrey R.; Thompson, Janet K.; O'Riordan, Catherine A.; Nepf, Heidi M.

    1990-01-01

    We carried out experiments studying the hydrodynamics of bivalve siphonal currents in a laboratory flume. Rather than use living animals, we devised a simple, model siphon pair connected to a pump. Fluorescence-based flow visualization was used to characterize siphon-jet flows for several geometric configurations and flow speeds. These measurements show that the boundary-layer velocity profile, siphon height, siphon pair orientation, and size of siphon structure all affect the vertical distribution of the excurrent flow downstream of the siphon pair and the fraction of excurrent that is refiltered. The observed flows may effect both the clearance rate of an entire population of siphonate bivalves as well as the efficiency of feeding of any individual. Our results imply that field conditions are properly represented in laboratory flume studies of phytoplankton biomass losses to benthic bivalves when the shear velocity and bottom roughness are matched to values found in the field. Numerical models of feeding by a bivalve population should include an effective sink distribution which is created by the combined incurrent-excurrent flow field. Near-bed flows need to be accounted for to properly represent these benthic-pelagic exchanges. We also present velocity measurements made with a laser-Doppler anemometer (LDA) for a single configuration (siphons flush with bed, inlet downstream) that show that the siphonal currents have a significant local effect on the properties of a turbulent boundary layer.

  6. Can quantum probability provide a new direction for cognitive modeling?

    Science.gov (United States)

    Pothos, Emmanuel M; Busemeyer, Jerome R

    2013-06-01

    Classical (Bayesian) probability (CP) theory has led to an influential research tradition for modeling cognitive processes. Cognitive scientists have been trained to work with CP principles for so long that it is hard even to imagine alternative ways to formalize probabilities. However, in physics, quantum probability (QP) theory has been the dominant probabilistic approach for nearly 100 years. Could QP theory provide us with any advantages in cognitive modeling as well? Note first that both CP and QP theory share the fundamental assumption that it is possible to model cognition on the basis of formal, probabilistic principles. But why consider a QP approach? The answers are that (1) there are many well-established empirical findings (e.g., from the influential Tversky, Kahneman research tradition) that are hard to reconcile with CP principles; and (2) these same findings have natural and straightforward explanations with quantum principles. In QP theory, probabilistic assessment is often strongly context- and order-dependent, individual states can be superposition states (that are impossible to associate with specific values), and composite systems can be entangled (they cannot be decomposed into their subsystems). All these characteristics appear perplexing from a classical perspective. However, our thesis is that they provide a more accurate and powerful account of certain cognitive processes. We first introduce QP theory and illustrate its application with psychological examples. We then review empirical findings that motivate the use of quantum theory in cognitive theory, but also discuss ways in which QP and CP theories converge. Finally, we consider the implications of a QP theory approach to cognition for human rationality.

  7. Computational cognitive modeling for the diagnosis of Specific Language Impairment.

    Science.gov (United States)

    Oliva, Jesus; Serrano, J Ignacio; del Castillo, M Dolores; Iglesias, Angel

    2013-01-01

    Specific Language Impairment (SLI), as many other cognitive deficits, is difficult to diagnose given its heterogeneous profile and its overlap with other impairments. Existing techniques are based on different criteria using behavioral variables on different tasks. In this paper we propose a methodology for the diagnosis of SLI that uses computational cognitive modeling in order to capture the internal mechanisms of the normal and impaired brain. We show that machine learning techniques that use the information of these models perform better than those that only use behavioral variables.

  8. Modelling application for cognitive reliability and error analysis method

    Directory of Open Access Journals (Sweden)

    Fabio De Felice

    2013-10-01

    Full Text Available The automation of production systems has delegated to machines the execution of highly repetitive and standardized tasks. In the last decade, however, the failure of the automatic factory model has led to partially automated configurations of production systems. Therefore, in this scenario, centrality and responsibility of the role entrusted to the human operators are exalted because it requires problem solving and decision making ability. Thus, human operator is the core of a cognitive process that leads to decisions, influencing the safety of the whole system in function of their reliability. The aim of this paper is to propose a modelling application for cognitive reliability and error analysis method.

  9. A computational model of perception and action for cognitive robotics.

    Science.gov (United States)

    Haazebroek, Pascal; van Dantzig, Saskia; Hommel, Bernhard

    2011-11-01

    Robots are increasingly expected to perform tasks in complex environments. To this end, engineers provide them with processing architectures that are based on models of human information processing. In contrast to traditional models, where information processing is typically set up in stages (i.e., from perception to cognition to action), it is increasingly acknowledged by psychologists and robot engineers that perception and action are parts of an interactive and integrated process. In this paper, we present HiTEC, a novel computational (cognitive) model that allows for direct interaction between perception and action as well as for cognitive control, demonstrated by task-related attentional influences. Simulation results show that key behavioral studies can be readily replicated. Three processing aspects of HiTEC are stressed for their importance for cognitive robotics: (1) ideomotor learning of action control, (2) the influence of task context and attention on perception, action planning, and learning, and (3) the interaction between perception and action planning. Implications for the design of cognitive robotics are discussed.

  10. For a Cognitive Model of Subjective Memory Awareness.

    Science.gov (United States)

    Dalla Barba, Gianfranco; La Corte, Valentina; Dubois, Bruno

    2015-09-24

    The clinical challenge in subjective memory decline (SMD) is to identify which individuals will present memory deficits. Since its early description from Babinsky, who coined the term 'anosognosia' (i.e., the lack of awareness of deficit), the awareness of cognitive impairment is crucial in clinical neuropsychology. We propose a cognitive model in which SMD and anosognosia can be considered two opposite forms of distorted awareness of cognitive performance and can be accounted for within a model in which consciousness of memory performance can vary in a continuum from normal awareness of performance (preserved or impaired) to anosognosia through a disorder of consciousness related to SMD that we call "cognitive dysgnosia", i.e., awareness of normal performance as impaired. This model suggests that the neuropsychological assessment of memory performance should always be coupled with a deep evaluation of awareness of the subject's memory profile, which allow to better identify the disorder of consciousness with or without cognitive impairment. In this line, it seems necessary to develop more sensitive neuropsychological tools in order to discriminate, within the SMD, individuals who are likely to develop clinical Alzheimer's disease from those whose memory decline complaint is not associated with an underlying neurodegenerative pathology.

  11. Dynamic scene stitching driven by visual cognition model.

    Science.gov (United States)

    Zou, Li-hui; Zhang, Dezheng; Wulamu, Aziguli

    2014-01-01

    Dynamic scene stitching still has a great challenge in maintaining the global key information without missing or deforming if multiple motion interferences exist in the image acquisition system. Object clips, motion blurs, or other synthetic defects easily occur in the final stitching image. In our research work, we proceed from human visual cognitive mechanism and construct a hybrid-saliency-based cognitive model to automatically guide the video volume stitching. The model consists of three elements of different visual stimuli, that is, intensity, edge contour, and scene depth saliencies. Combined with the manifold-based mosaicing framework, dynamic scene stitching is formulated as a cut path optimization problem in a constructed space-time graph. The cutting energy function for column width selections is defined according to the proposed visual cognition model. The optimum cut path can minimize the cognitive saliency difference throughout the whole video volume. The experimental results show that it can effectively avoid synthetic defects caused by different motion interferences and summarize the key contents of the scene without loss. The proposed method gives full play to the role of human visual cognitive mechanism for the stitching. It is of high practical value to environmental surveillance and other applications.

  12. Dynamic Scene Stitching Driven by Visual Cognition Model

    Directory of Open Access Journals (Sweden)

    Li-hui Zou

    2014-01-01

    Full Text Available Dynamic scene stitching still has a great challenge in maintaining the global key information without missing or deforming if multiple motion interferences exist in the image acquisition system. Object clips, motion blurs, or other synthetic defects easily occur in the final stitching image. In our research work, we proceed from human visual cognitive mechanism and construct a hybrid-saliency-based cognitive model to automatically guide the video volume stitching. The model consists of three elements of different visual stimuli, that is, intensity, edge contour, and scene depth saliencies. Combined with the manifold-based mosaicing framework, dynamic scene stitching is formulated as a cut path optimization problem in a constructed space-time graph. The cutting energy function for column width selections is defined according to the proposed visual cognition model. The optimum cut path can minimize the cognitive saliency difference throughout the whole video volume. The experimental results show that it can effectively avoid synthetic defects caused by different motion interferences and summarize the key contents of the scene without loss. The proposed method gives full play to the role of human visual cognitive mechanism for the stitching. It is of high practical value to environmental surveillance and other applications.

  13. Modeling and Evaluating Emotions Impact on Cognition

    Science.gov (United States)

    2013-07-01

    International Conference on Automatic Face and Gesture Recognition . Shanghai, China, April 2013 • Wenji Mao and Jonathan Gratch. Modeling Social...Modeling, Lorentz Center, Leiden. August 2011 • Keynote speaker, IEEE International Conference on Automatic Face and Gesture Recognition , Santa

  14. The Role of Cognitive Modeling in Achieving Communicative Intentions

    CERN Document Server

    Walker, M; Walker, Marilyn; Rambow, Owen

    1994-01-01

    A discourse planner for (task-oriented) dialogue must be able to make choices about whether relevant, but optional information (for example, the "satellites" in an RST-based planner) should be communicated. We claim that effective text planners must explicitly model aspects of the Hearer's cognitive state, such as what the hearer is attending to and what inferences the hearer can draw, in order to make these choices. We argue that a mere representation of the Hearer's knowledge is inadequate. We support this claim by (1) an analysis of naturally occurring dialogue, and (2) by simulating the generation of discourses in a situation in which we can vary the cognitive parameters of the hearer. Our results show that modeling cognitive state can lead to more effective discourses (measured with respect to a simple task).

  15. MAGELLAN: a cognitive map-based model of human wayfinding.

    Science.gov (United States)

    Manning, Jeremy R; Lew, Timothy F; Li, Ningcheng; Sekuler, Robert; Kahana, Michael J

    2014-06-01

    In an unfamiliar environment, searching for and navigating to a target requires that spatial information be acquired, stored, processed, and retrieved. In a study encompassing all of these processes, participants acted as taxicab drivers who learned to pick up and deliver passengers in a series of small virtual towns. We used data from these experiments to refine and validate MAGELLAN, a cognitive map-based model of spatial learning and wayfinding. MAGELLAN accounts for the shapes of participants' spatial learning curves, which measure their experience-based improvement in navigational efficiency in unfamiliar environments. The model also predicts the ease (or difficulty) with which different environments are learned and, within a given environment, which landmarks will be easy (or difficult) to localize from memory. Using just 2 free parameters, MAGELLAN provides a useful account of how participants' cognitive maps evolve over time with experience, and how participants use the information stored in their cognitive maps to navigate and explore efficiently.

  16. The potential of using quantum theory to build models of cognition.

    Science.gov (United States)

    Wang, Zheng; Busemeyer, Jerome R; Atmanspacher, Harald; Pothos, Emmanuel M

    2013-10-01

    Quantum cognition research applies abstract, mathematical principles of quantum theory to inquiries in cognitive science. It differs fundamentally from alternative speculations about quantum brain processes. This topic presents new developments within this research program. In the introduction to this topic, we try to answer three questions: Why apply quantum concepts to human cognition? How is quantum cognitive modeling different from traditional cognitive modeling? What cognitive processes have been modeled using a quantum account? In addition, a brief introduction to quantum probability theory and a concrete example is provided to illustrate how a quantum cognitive model can be developed to explain paradoxical empirical findings in psychological literature.

  17. Computational Modeling and Simulation of Attitude Change. Part 1, Connectionist Models and Simulations of Cognitive Dissonance: an Overview

    OpenAIRE

    Voinea, Camelia Florela

    2013-01-01

    Cognitive Dissonance Theory is considered part of the cognitive consistency theories in Social Psychology. They uncover a class of conceptual models which describe the attitude change as a cognitive consistency-seeking issue. As these conceptual models requested more complex operational expression, algebraic, mathematical and, lately, computational modeling approaches of cognitive consistency have been developed. Part 1 of this work provides an overview of the connectionist modeling of cognit...

  18. Computational Modeling and Simulation of Attitude Change. Part 1, Connectionist Models and Simulations of Cognitive Dissonance: an Overview

    OpenAIRE

    Voinea, Camelia Florela

    2013-01-01

    Cognitive Dissonance Theory is considered part of the cognitive consistency theories in Social Psychology. They uncover a class of conceptual models which describe the attitude change as a cognitive consistency-seeking issue. As these conceptual models requested more complex operational expression, algebraic, mathematical and, lately, computational modeling approaches of cognitive consistency have been developed. Part 1 of this work provides an overview of the connectionist modeling of cognit...

  19. Computational models of music perception and cognition I: The perceptual and cognitive processing chain

    Science.gov (United States)

    Purwins, Hendrik; Herrera, Perfecto; Grachten, Maarten; Hazan, Amaury; Marxer, Ricard; Serra, Xavier

    2008-09-01

    We present a review on perception and cognition models designed for or applicable to music. An emphasis is put on computational implementations. We include findings from different disciplines: neuroscience, psychology, cognitive science, artificial intelligence, and musicology. The article summarizes the methodology that these disciplines use to approach the phenomena of music understanding, the localization of musical processes in the brain, and the flow of cognitive operations involved in turning physical signals into musical symbols, going from the transducers to the memory systems of the brain. We discuss formal models developed to emulate, explain and predict phenomena involved in early auditory processing, pitch processing, grouping, source separation, and music structure computation. We cover generic computational architectures of attention, memory, and expectation that can be instantiated and tuned to deal with specific musical phenomena. Criteria for the evaluation of such models are presented and discussed. Thereby, we lay out the general framework that provides the basis for the discussion of domain-specific music models in Part II.

  20. Crisis-transitions in athletes: current emphases on cognitive and contextual factors.

    Science.gov (United States)

    Stambulova, Natalia B

    2017-08-01

    During the last decade, the field of athlete career research has seen much expansion. Researchers established the holistic lifespan and ecological approaches, introduced cultural praxis of athletes' careers paradigm, and updated the taxonomy of athletes' transitions. However, recent transition research focused mainly on the transition process and factors contributing to successful transitions, while crisis-transitions and factors contributing to ineffective coping have been largely ignored. The aim of this paper is to facilitate relevant research and practice through (1) positioning athletes' developmental crises within the context of the current transition literature, (2) introducing two new approaches (termed 'cognitive turn' and 'cultural turn') with a potential to enhance our understanding of the phenomenon, and (3) outlining crisis-coping interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Using data-driven model-brain mappings to constrain formal models of cognition

    NARCIS (Netherlands)

    Borst, Jelmer P; Nijboer, Menno; Taatgen, Niels A; van Rijn, Hedderik; Anderson, John R

    2015-01-01

    In this paper we propose a method to create data-driven mappings from components of cognitive models to brain regions. Cognitive models are notoriously hard to evaluate, especially based on behavioral measures alone. Neuroimaging data can provide additional constraints, but this requires a mapping f

  2. System identification and adaptive control theory and applications of the neurofuzzy and fuzzy cognitive network models

    CERN Document Server

    Boutalis, Yiannis; Kottas, Theodore; Christodoulou, Manolis A

    2014-01-01

    Presenting current trends in the development and applications of intelligent systems in engineering, this monograph focuses on recent research results in system identification and control. The recurrent neurofuzzy and the fuzzy cognitive network (FCN) models are presented.  Both models are suitable for partially-known or unknown complex time-varying systems. Neurofuzzy Adaptive Control contains rigorous proofs of its statements which result in concrete conclusions for the selection of the design parameters of the algorithms presented. The neurofuzzy model combines concepts from fuzzy systems and recurrent high-order neural networks to produce powerful system approximations that are used for adaptive control. The FCN model  stems  from fuzzy cognitive maps and uses the notion of “concepts” and their causal relationships to capture the behavior of complex systems. The book shows how, with the benefit of proper training algorithms, these models are potent system emulators suitable for use in engineering s...

  3. Computational Models of Relational Processes in Cognitive Development

    Science.gov (United States)

    Halford, Graeme S.; Andrews, Glenda; Wilson, William H.; Phillips, Steven

    2012-01-01

    Acquisition of relational knowledge is a core process in cognitive development. Relational knowledge is dynamic and flexible, entails structure-consistent mappings between representations, has properties of compositionality and systematicity, and depends on binding in working memory. We review three types of computational models relevant to…

  4. A Tutorial Introduction to Bayesian Models of Cognitive Development

    Science.gov (United States)

    Perfors, Amy; Tenenbaum, Joshua B.; Griffiths, Thomas L.; Xu, Fei

    2011-01-01

    We present an introduction to Bayesian inference as it is used in probabilistic models of cognitive development. Our goal is to provide an intuitive and accessible guide to the "what", the "how", and the "why" of the Bayesian approach: what sorts of problems and data the framework is most relevant for, and how and why it may be useful for…

  5. Computational Models of Relational Processes in Cognitive Development

    Science.gov (United States)

    Halford, Graeme S.; Andrews, Glenda; Wilson, William H.; Phillips, Steven

    2012-01-01

    Acquisition of relational knowledge is a core process in cognitive development. Relational knowledge is dynamic and flexible, entails structure-consistent mappings between representations, has properties of compositionality and systematicity, and depends on binding in working memory. We review three types of computational models relevant to…

  6. Building Bridges between Neuroscience, Cognition and Education with Predictive Modeling

    Science.gov (United States)

    Stringer, Steve; Tommerdahl, Jodi

    2015-01-01

    As the field of Mind, Brain, and Education seeks new ways to credibly bridge the gap between neuroscience, the cognitive sciences, and education, various connections are being developed and tested. This article presents a framework and offers examples of one approach, predictive modeling within a virtual educational system that can include…

  7. Dynamical Cognitive Models of Social Issues in Russia

    Science.gov (United States)

    Mitina, Olga; Abraham, Fred; Petrenko, Victor

    We examine and model dynamics in three areas of social cognition: (1) political transformations within Russia, (2) evaluation of political trends in other countries by Russians, and (3) evaluation of Russian stereotypes concerning women. We try to represent consciousness as vectorfields and trajectories in a cognitive state space. We use psychosemantic techniques that allow definition of the state space and the systematic construction of these vectorfields and trajectories and their portrait from research data. Then we construct models to fit them, using multiple regression methods to obtain linear differential equations. These dynamical models of social cognition fit the data quite well. (1) The political transformations were modeled by a spiral repellor in a two-dimensional space of a democratic-totalitarian factor and social depression-optimism factor. (2) The evaluation of alien political trends included a flow away from a saddle toward more stable and moderate political regimes in a 2D space, of democratic-totalitarian and unstable-stable cognitive dimensions. (3) The gender study showed expectations (attractors) for more liberated, emancipated roles for women in the future.

  8. Building Bridges between Neuroscience, Cognition and Education with Predictive Modeling

    Science.gov (United States)

    Stringer, Steve; Tommerdahl, Jodi

    2015-01-01

    As the field of Mind, Brain, and Education seeks new ways to credibly bridge the gap between neuroscience, the cognitive sciences, and education, various connections are being developed and tested. This article presents a framework and offers examples of one approach, predictive modeling within a virtual educational system that can include…

  9. Computational modeling in cognitive science: a manifesto for change.

    Science.gov (United States)

    Addyman, Caspar; French, Robert M

    2012-07-01

    Computational modeling has long been one of the traditional pillars of cognitive science. Unfortunately, the computer models of cognition being developed today have not kept up with the enormous changes that have taken place in computer technology and, especially, in human-computer interfaces.  For all intents and purposes, modeling is still done today as it was 25, or even 35, years ago. Everyone still programs in his or her own favorite programming language, source code is rarely made available, accessibility of models to non-programming researchers is essentially non-existent, and even for other modelers, the profusion of source code in a multitude of programming languages, written without programming guidelines, makes it almost impossible to access, check, explore, re-use, or continue to develop. It is high time to change this situation, especially since the tools are now readily available to do so. We propose that the modeling community adopt three simple guidelines that would ensure that computational models would be accessible to the broad range of researchers in cognitive science. We further emphasize the pivotal role that journal editors must play in making computational models accessible to readers of their journals.

  10. Optimizing Cognitive Development over the Life Course and Preventing Cognitive Decline: Introducing the Cognitive Health Environment Life Course Model (CHELM)

    Science.gov (United States)

    Anstey, Kaarin J.

    2014-01-01

    Optimal cognitive development is defined in this article as the highest level of cognitive function reached in each cognitive domain given a person's biological and genetic disposition, and the highest possible maintenance of cognitive function over the adult life course. Theoretical perspectives underpinning the development of a framework…

  11. Optimizing Cognitive Development over the Life Course and Preventing Cognitive Decline: Introducing the Cognitive Health Environment Life Course Model (CHELM)

    Science.gov (United States)

    Anstey, Kaarin J.

    2014-01-01

    Optimal cognitive development is defined in this article as the highest level of cognitive function reached in each cognitive domain given a person's biological and genetic disposition, and the highest possible maintenance of cognitive function over the adult life course. Theoretical perspectives underpinning the development of a framework…

  12. Test of the depression distress amplification model in young adults with elevated risk of current suicidality.

    Science.gov (United States)

    Capron, Daniel W; Lamis, Dorian A; Schmidt, Norman B

    2014-11-30

    Suicide is a leading cause of death among young adults and the rate of suicide has been increasing for decades. A depression distress amplification model posits that young adults with comorbid depression and anxiety have elevated suicide rates due to the intensification of their depressive symptoms by anxiety sensitivity cognitive concerns. The current study tested the effects of anxiety sensitivity subfactors as well as the depression distress amplification model in a very large sample of college students with elevated suicide risk. Participants were 721 college students who were at elevated risk of suicidality (scored>0 on the Beck Scale for Suicide Ideation). Consistent with prior work, anxiety sensitivity cognitive concerns, but not physical or social concerns, were associated with suicidal ideation. Consistent with the depression distress amplification model, in individuals high in depression, anxiety sensitivity cognitive concerns predicted elevated suicidal ideation but not among those with low depression. The results of this study corroborate the role of anxiety sensitivity cognitive concerns and the depression distress amplification model in suicidal ideation among a large potentially high-risk group of college students. The depression distress amplification model suggests a specific mechanism, anxiety sensitivity cognitive concerns, that may be responsible for increased suicide rates among those with comorbid anxiety and depression.

  13. Cognitive deficits in geriatric depression: clinical correlates and implications for current and future treatment.

    Science.gov (United States)

    Morimoto, Sarah Shizuko; Alexopoulos, George S

    2013-12-01

    The purpose of this article is to identify the cognitive deficits commonly associated with geriatric depression and describe their clinical significance. The complex relationship between geriatric depression and dementia is summarized and possible shared mechanisms discussed. Evidence regarding whether the cognitive deficits in depression may be mitigated with medication or with computerized cognitive remediation is presented. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Cognitive Modeling of Individual Variation in Reference Production and Comprehension.

    Science.gov (United States)

    Hendriks, Petra

    2016-01-01

    A challenge for most theoretical and computational accounts of linguistic reference is the observation that language users vary considerably in their referential choices. Part of the variation observed among and within language users and across tasks may be explained from variation in the cognitive resources available to speakers and listeners. This paper presents a computational model of reference production and comprehension developed within the cognitive architecture ACT-R. Through simulations with this ACT-R model, it is investigated how cognitive constraints interact with linguistic constraints and features of the linguistic discourse in speakers' production and listeners' comprehension of referring expressions in specific tasks, and how this interaction may give rise to variation in referential choice. The ACT-R model of reference explains and predicts variation among language users in their referential choices as a result of individual and task-related differences in processing speed and working memory capacity. Because of limitations in their cognitive capacities, speakers sometimes underspecify or overspecify their referring expressions, and listeners sometimes choose incorrect referents or are overly liberal in their interpretation of referring expressions.

  15. Modeling cognitive and emotional processes: a novel neural network architecture.

    Science.gov (United States)

    Khashman, Adnan

    2010-12-01

    In our continuous attempts to model natural intelligence and emotions in machine learning, many research works emerge with different methods that are often driven by engineering concerns and have the common goal of modeling human perception in machines. This paper aims to go further in that direction by investigating the integration of emotion at the structural level of cognitive systems using the novel emotional DuoNeural Network (DuoNN). This network has hidden layer DuoNeurons, where each has two embedded neurons: a dorsal neuron and a ventral neuron for cognitive and emotional data processing, respectively. When input visual stimuli are presented to the DuoNN, the dorsal cognitive neurons process local features while the ventral emotional neurons process the entire pattern. We present the computational model and the learning algorithm of the DuoNN, the input information-cognitive and emotional-parallel streaming method, and a comparison between the DuoNN and a recently developed emotional neural network. Experimental results show that the DuoNN architecture, configuration, and the additional emotional information processing, yield higher recognition rates and faster learning and decision making.

  16. Cognitive Modeling of Individual Variation in Reference Production and Comprehension

    Directory of Open Access Journals (Sweden)

    Petra eHendriks

    2016-04-01

    Full Text Available A challenge for most theoretical and computational accounts of linguistic reference is the observation that language users vary considerably in their referential choices. Part of the variation observed among and within language users and across tasks may be explained from variation in the cognitive resources available to speakers and listeners. This paper presents a computational model of reference production and comprehension developed within the cognitive architecture ACT-R. Through simulations with this ACT-R model, it is investigated how cognitive constraints interact with linguistic constraints and features of the linguistic discourse in speakers’ production and listeners’ comprehension of referring expressions in specific tasks, and how this interaction may give rise to variation in referential choice. The ACT-R model of reference explains and predicts variation among language users in their referential choices as a result of individual and task-related differences in processing speed and working memory capacity. Because of limitations in their cognitive capacities, speakers sometimes underspecify or overspecify their referring expressions, and listeners sometimes choose incorrect referents or are overly liberal in their interpretation of referring expressions.

  17. Assessing executive function using a computer game: computational modeling of cognitive processes.

    Science.gov (United States)

    Hagler, Stuart; Jimison, Holly Brugge; Pavel, Misha

    2014-07-01

    Early and reliable detection of cognitive decline is one of the most important challenges of current healthcare. In this project, we developed an approach whereby a frequently played computer game can be used to assess a variety of cognitive processes and estimate the results of the pen-and-paper trail making test (TMT)--known to measure executive function, as well as visual pattern recognition, speed of processing, working memory, and set-switching ability. We developed a computational model of the TMT based on a decomposition of the test into several independent processes, each characterized by a set of parameters that can be estimated from play of a computer game designed to resemble the TMT. An empirical evaluation of the model suggests that it is possible to use the game data to estimate the parameters of the underlying cognitive processes and using the values of the parameters to estimate the TMT performance. Cognitive measures and trends in these measures can be used to identify individuals for further assessment, to provide a mechanism for improving the early detection of neurological problems, and to provide feedback and monitoring for cognitive interventions in the home.

  18. Cognitive Modeling at ICCM: State of the Art and Future Directions.

    Science.gov (United States)

    Taatgen, Niels A; van Vugt, Marieke K; Borst, Jelmer P; Mehlhorn, Katja

    2016-01-01

    The goal of cognitive modeling is to build faithful simulations of human cognition. One of the challenges is that multiple models can often explain the same phenomena. Another challenge is that models are often very hard to understand, explore, and reuse by others. We discuss some of the solutions that were discussed during the 2015 International Conference on Cognitive Modeling.

  19. Cortical Amyloid β Deposition and Current Depressive Symptoms in Alzheimer Disease and Mild Cognitive Impairment.

    Science.gov (United States)

    Chung, Jun Ku; Plitman, Eric; Nakajima, Shinichiro; Chakravarty, M Mallar; Caravaggio, Fernando; Gerretsen, Philip; Iwata, Yusuke; Graff-Guerrero, Ariel

    2016-05-01

    Depressive symptoms are frequently seen in patients with dementia and mild cognitive impairment (MCI). Evidence suggests that there may be a link between current depressive symptoms and Alzheimer disease (AD)-associated pathological changes, such as an increase in cortical amyloid-β (Aβ). However, limited in vivo studies have explored the relationship between current depressive symptoms and cortical Aβ in patients with MCI and AD. Our study, using a large sample of 455 patients with MCI and 153 patients with AD from the Alzheimer's disease Neuroimaging Initiatives, investigated whether current depressive symptoms are related to cortical Aβ deposition. Depressive symptoms were assessed using the Geriatric Depression Scale and Neuropsychiatric Inventory-depression/dysphoria. Cortical Aβ was quantified using positron emission tomography with the Aβ probe(18)F-florbetapir (AV-45).(18)F-florbetapir standardized uptake value ratio (AV-45 SUVR) from the frontal, cingulate, parietal, and temporal regions was estimated. A global AV-45 SUVR, defined as the average of frontal, cingulate, precuneus, and parietal cortex, was also used. We observed that current depressive symptoms were not related to cortical Aβ, after controlling for potential confounds, including history of major depression. We also observed that there was no difference in cortical Aβ between matched participants with high and low depressive symptoms, as well as no difference between matched participants with the presence and absence of depressive symptoms. The association between depression and cortical Aβ deposition does not exist, but the relationship is highly influenced by stressful events in the past, such as previous depressive episodes, and complex interactions of different pathways underlying both depression and dementia.

  20. A cognitive model for software architecture complexity

    NARCIS (Netherlands)

    Bouwers, E.; Lilienthal, C.; Visser, J.; Van Deursen, A.

    2010-01-01

    Evaluating the complexity of the architecture of a softwaresystem is a difficult task. Many aspects have to be considered to come to a balanced assessment. Several architecture evaluation methods have been proposed, but very few define a quality model to be used during the evaluation process. In add

  1. Extending Social Cognition Models of Health Behaviour

    Science.gov (United States)

    Abraham, Charles; Sheeran, Paschal; Henderson, Marion

    2011-01-01

    A cross-sectional study assessed the extent to which indices of social structure, including family socio-economic status (SES), social deprivation, gender and educational/lifestyle aspirations correlated with adolescent condom use and added to the predictive utility of a theory of planned behaviour model. Analyses of survey data from 824 sexually…

  2. Extending Social Cognition Models of Health Behaviour

    Science.gov (United States)

    Abraham, Charles; Sheeran, Paschal; Henderson, Marion

    2011-01-01

    A cross-sectional study assessed the extent to which indices of social structure, including family socio-economic status (SES), social deprivation, gender and educational/lifestyle aspirations correlated with adolescent condom use and added to the predictive utility of a theory of planned behaviour model. Analyses of survey data from 824 sexually…

  3. Cognitive rehabilitation reduces cognitive impairment and normalizes hippocampal CA1 architecture in a rat model of vascular dementia

    OpenAIRE

    Langdon, Kristopher D.; Granter-Button, Shirley; Carolyn W Harley; Moody-Corbett, Frances; Peeling, James; Corbett, Dale

    2013-01-01

    Dementia is a major cause of morbidity in the western society. Pharmacological therapies to delay the progression of cognitive impairments are modestly successful. Consequently, new therapies are urgently required to improve cognitive deficits associated with dementia. We evaluated the effects of physical and cognitive activity on learning and memory in a rat model of vascular dementia (VasD). Male Sprague-Dawley rats (6 months old) were exposed to either regular chow or a diet rich in satura...

  4. Current perspectives on Internet delivered cognitive behavioral therapy for adults with anxiety and related disorders

    Directory of Open Access Journals (Sweden)

    Mewton L

    2014-01-01

    Full Text Available Louise Mewton, Jessica Smith, Pieter Rossouw, Gavin Andrews Clinical Research Unit for Anxiety and Depression, St Vincent’s Hospital, Sydney, NSW, Australia Abstract: The aim of the current review is to provide a summary of research into Internet-delivered cognitive behavioral therapy (iCBT for anxiety disorders. We include 37 randomized controlled trials that examined the efficacy of iCBT programs in adults (aged over 18 years, as compared with waiting list or active control. The included studies were identified from Medline searches and from reference lists, and only published data were included. Several trials of iCBT for generalized anxiety disorder, panic disorder, and social phobia were identified. Two trials of iCBT for obsessive-compulsive disorder were identified, whilst one trial each was identified for hypochondriasis, specific phobia (spiders, and post-traumatic stress disorder. Finally, there were five trials that focused on transdiagnostic therapy for either a range of comorbid anxiety disorders or comorbid anxiety and depression. Between-group effect sizes were moderate to large for all disorders, and ranged from 0.30 to 2.53. iCBT was found to be commensurate with face-to-face cognitive behavioral therapy whether delivered individually or in group format. Guidance may not be necessary for iCBT to be effective for immediate gains, but may be more important in longer-term maintenance of symptom improvement and maximizing patient adherence. The clinical experience of the individual providing guidance does not appear to impact treatment outcomes. Future research needs to focus on the optimal level of guidance required to generate maximum patient benefits, whilst balancing the efficient use of clinician time and resources. Evidence-based contraindications to iCBT should also be developed so that the choice of treatment modality accurately reflects patients’ needs. Further research should be conducted into the effective elements of

  5. Current perspectives on Internet-delivered cognitive behavioral therapy for adults with anxiety and related disorders

    Science.gov (United States)

    Mewton, Louise; Smith, Jessica; Rossouw, Pieter; Andrews, Gavin

    2014-01-01

    The aim of the current review is to provide a summary of research into Internet-delivered cognitive behavioral therapy (iCBT) for anxiety disorders. We include 37 randomized controlled trials that examined the efficacy of iCBT programs in adults (aged over 18 years), as compared with waiting list or active control. The included studies were identified from Medline searches and from reference lists, and only published data were included. Several trials of iCBT for generalized anxiety disorder, panic disorder, and social phobia were identified. Two trials of iCBT for obsessive-compulsive disorder were identified, whilst one trial each was identified for hypochondriasis, specific phobia (spiders), and post-traumatic stress disorder. Finally, there were five trials that focused on transdiagnostic therapy for either a range of comorbid anxiety disorders or comorbid anxiety and depression. Between-group effect sizes were moderate to large for all disorders, and ranged from 0.30 to 2.53. iCBT was found to be commensurate with face-to-face cognitive behavioral therapy whether delivered individually or in group format. Guidance may not be necessary for iCBT to be effective for immediate gains, but may be more important in longer-term maintenance of symptom improvement and maximizing patient adherence. The clinical experience of the individual providing guidance does not appear to impact treatment outcomes. Future research needs to focus on the optimal level of guidance required to generate maximum patient benefits, whilst balancing the efficient use of clinician time and resources. Evidence-based contraindications to iCBT should also be developed so that the choice of treatment modality accurately reflects patients’ needs. Further research should be conducted into the effective elements of iCBT, as well as the extent to which therapy enhancers and advancing technology can be accommodated into established iCBT frameworks. PMID:24511246

  6. Transcranial Direct Current Stimulation over the Dorsolateral Prefrontal Cortex in Schizophrenia: A Quantitative Review of Cognitive Outcomes.

    Science.gov (United States)

    Mervis, Joshua E; Capizzi, Riley J; Boroda, Elias; MacDonald, Angus W

    2017-01-01

    Cognitive deficits are a core and disabling feature of psychotic disorders, specifically schizophrenia. Current treatments for impaired cognition in schizophrenia remain insufficient. Recent research suggests transcranial direct current stimulation (tDCS) targeting the dorsolateral prefrontal cortex can potentiate cognitive improvements in healthy individuals and those with psychiatric conditions, such as schizophrenia. However, this burgeoning literature has not been quantitatively evaluated. Through a literature search and quantitative review, we identified 194 papers on tDCS, psychosis, and cognition. Selection criteria included pre/post design and sham control to achieve specific sham-adjusted effect sizes. The 6 retained studies all address schizophrenia populations and include single and repeated stimulation, as well as within and between subject designs. Small positive effects were found for anodal stimulation on behavioral measures of attention and working memory, with tentative findings for cognitive ability and memory. Cathodal stimulation yielded a small positive effect on behaviorally measured cognitive ability. Neurophysiological measures of attention showed a small to medium down-modulation effect for anodal stimulation. Implications of these findings and guidelines for future research are discussed. As revealed by this report, due to the paucity of data available, much remains unknown regarding the clinical efficacy of tDCS in schizophrenia.

  7. Transcranial Direct Current Stimulation over the Dorsolateral Prefrontal Cortex in Schizophrenia: A Quantitative Review of Cognitive Outcomes

    Science.gov (United States)

    Mervis, Joshua E.; Capizzi, Riley J.; Boroda, Elias; MacDonald, Angus W.

    2017-01-01

    Cognitive deficits are a core and disabling feature of psychotic disorders, specifically schizophrenia. Current treatments for impaired cognition in schizophrenia remain insufficient. Recent research suggests transcranial direct current stimulation (tDCS) targeting the dorsolateral prefrontal cortex can potentiate cognitive improvements in healthy individuals and those with psychiatric conditions, such as schizophrenia. However, this burgeoning literature has not been quantitatively evaluated. Through a literature search and quantitative review, we identified 194 papers on tDCS, psychosis, and cognition. Selection criteria included pre/post design and sham control to achieve specific sham-adjusted effect sizes. The 6 retained studies all address schizophrenia populations and include single and repeated stimulation, as well as within and between subject designs. Small positive effects were found for anodal stimulation on behavioral measures of attention and working memory, with tentative findings for cognitive ability and memory. Cathodal stimulation yielded a small positive effect on behaviorally measured cognitive ability. Neurophysiological measures of attention showed a small to medium down-modulation effect for anodal stimulation. Implications of these findings and guidelines for future research are discussed. As revealed by this report, due to the paucity of data available, much remains unknown regarding the clinical efficacy of tDCS in schizophrenia. PMID:28210217

  8. Effects of transcranial direct current stimulation (tDCS) on cognition, symptoms, and smoking in schizophrenia: A randomized controlled study.

    Science.gov (United States)

    Smith, Robert C; Boules, Sylvia; Mattiuz, Sanela; Youssef, Mary; Tobe, Russell H; Sershen, Henry; Lajtha, Abel; Nolan, Karen; Amiaz, Revital; Davis, John M

    2015-10-01

    Schizophrenia is characterized by cognitive deficits which persist after acute symptoms have been treated or resolved. Transcranial direct current stimulation (tDCS) has been reported to improve cognition and reduce smoking craving in healthy subjects but has not been as carefully evaluated in a randomized controlled study for these effects in schizophrenia. We conducted a randomized double-blind, sham-controlled study of the effects of 5 sessions of tDCS (2 milliamps for 20minutes) on cognition, psychiatric symptoms, and smoking and cigarette craving in 37 outpatients with schizophrenia or schizoaffective disorder who were current smokers. Thirty subjects provided evaluable data on the MATRICS Consensus Cognitive Battery (MCCB), with the primary outcome measure, the MCCB Composite score. Active compared to sham tDCS subjects showed significant improvements after the fifth tDCS session in MCCB Composite score (p=0.008) and on the MCCB Working Memory (p=0.002) and Attention-Vigilance (p=0.027) domain scores, with large effect sizes. MCCB Composite and Working Memory domain scores remained significant at Benjamini-Hochberg corrected significance levels (α=0.05). There were no statistically significant effects on secondary outcome measures of psychiatric symptoms (PANSS scores), hallucinations, cigarette craving, or cigarettes smoked. The positive effects of tDCS on cognitive performance suggest a potential efficacious treatment for cognitive deficits in partially recovered chronic schizophrenia outpatients that should be further investigated.

  9. Defining a Family of Cognitive Diagnosis Models Using Log-Linear Models with Latent Variables

    Science.gov (United States)

    Henson, Robert A.; Templin, Jonathan L.; Willse, John T.

    2009-01-01

    This paper uses log-linear models with latent variables (Hagenaars, in "Loglinear Models with Latent Variables," 1993) to define a family of cognitive diagnosis models. In doing so, the relationship between many common models is explicitly defined and discussed. In addition, because the log-linear model with latent variables is a general model for…

  10. A Model for Cognitive Process of Neologisms Translation

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Moghadas

    2014-03-01

    Full Text Available Over the past three decades Process-oriented Descriptive Translation Studies has developed noticeably. Think-aloud protocols (TAPs, as a verbal report, are still the most applied empirical method to investigate the complex and conscious processes of translator’s mind during translating. This article deals with the cognitive process of professional translators’ problem-solving to translate a neologism from English source text into Persian by using TAPs. Likewise, the researcher has also used the means of video recording to observe the other behaviors of participants during the problem solving. The results indicate that the professional translators do not use one single way of performing a translation task and the complexity of the process of problem-solving (neologisms translation depends on the translation competence of translators. Finally, the researcher has also presented a cognitive model for the translation process of neologisms in ideal situations. As the translation universals are cognitive phenomena, the cognitive model presented here can be a pattern for trainee translators in education to visualize the natural process of neologism translation.

  11. Hierarchical Heteroclinics in Dynamical Model of Cognitive Processes: Chunking

    Science.gov (United States)

    Afraimovich, Valentin S.; Young, Todd R.; Rabinovich, Mikhail I.

    Combining the results of brain imaging and nonlinear dynamics provides a new hierarchical vision of brain network functionality that is helpful in understanding the relationship of the network to different mental tasks. Using these ideas it is possible to build adequate models for the description and prediction of different cognitive activities in which the number of variables is usually small enough for analysis. The dynamical images of different mental processes depend on their temporal organization and, as a rule, cannot be just simple attractors since cognition is characterized by transient dynamics. The mathematical image for a robust transient is a stable heteroclinic channel consisting of a chain of saddles connected by unstable separatrices. We focus here on hierarchical chunking dynamics that can represent several cognitive activities. Chunking is the dynamical phenomenon that means dividing a long information chain into shorter items. Chunking is known to be important in many processes of perception, learning, memory and cognition. We prove that in the phase space of the model that describes chunking there exists a new mathematical object — heteroclinic sequence of heteroclinic cycles — using the technique of slow-fast approximations. This new object serves as a skeleton of motions reflecting sequential features of hierarchical chunking dynamics and is an adequate image of the chunking processing.

  12. Agent-based cognitive model for human resources competence management.

    Science.gov (United States)

    Oliveira, Stefan; Gluz, João Carlos

    2010-01-01

    This chapter presents an agent-based cognitive model aimed to represent human competency concepts and competence management processes of psychological nature. This model is implemented by a multiagent system application intended to help managers of software development projects to select, based on the competence management model, the right professionals to integrate a development team. There are several software engineering methodologies that can be used to design and develop multiagent systems. However, due to the necessity to handle human competency concepts of cognitive nature, like aptitudes, interests, abilities and knowledge, we were driven to choose methodologies that can handle these concepts since the inception of the system. To do so, we integrated the TROPOS methodology, and a set of software engineering methods derived from intelligent tutoring systems research to successfully analyze and design the proposed system. At the end of the paper we present a study case, showing how the proposed system should be applied to the domain of website development.

  13. Learning Classification Models of Cognitive Conditions from Subtle Behaviors in the Digital Clock Drawing Test

    Science.gov (United States)

    Souillard-Mandar, William; Davis, Randall; Rudin, Cynthia; Au, Rhoda; Libon, David J.; Swenson, Rodney; Price, Catherine C.; Lamar, Melissa; Penney, Dana L.

    2015-01-01

    The Clock Drawing Test – a simple pencil and paper test – has been used for more than 50 years as a screening tool to differentiate normal individuals from those with cognitive impairment, and has proven useful in helping to diagnose cognitive dysfunction associated with neurological disorders such as Alzheimer’s disease, Parkinson’s disease, and other dementias and conditions. We have been administering the test using a digitizing ballpoint pen that reports its position with considerable spatial and temporal precision, making available far more detailed data about the subject’s performance. Using pen stroke data from these drawings categorized by our software, we designed and computed a large collection of features, then explored the tradeoffs in performance and interpretability in classifiers built using a number of different subsets of these features and a variety of different machine learning techniques. We used traditional machine learning methods to build prediction models that achieve high accuracy. We operationalized widely used manual scoring systems so that we could use them as benchmarks for our models. We worked with clinicians to define guidelines for model interpretability, and constructed sparse linear models and rule lists designed to be as easy to use as scoring systems currently used by clinicians, but more accurate. While our models will require additional testing for validation, they offer the possibility of substantial improvement in detecting cognitive impairment earlier than currently possible, a development with considerable potential impact in practice. PMID:27057085

  14. Cognitive Systems

    DEFF Research Database (Denmark)

    and its relation and potential over current artificial intelligence architectures. Machine learning models that learn from data and previous knowledge will play an increasingly important role in all levels of cognition as large real world digital environments (such as the Internet) usually are too complex...... to be modeled within a limited set of predefined specifications. There will inevitably be a need for robust decisions and behaviors in novel situations that include handling of conflicts and ambiguities based on the capability and knowledge of the artificial cognitive system. Further, there is a need......, cognitive psychology, and semantics. However, machine learning for signal processing plays a key role at all the levels of the cognitive processes, and we expect this to be a new emerging trend in our community in the coming years. Current examples of the use of machine learning for signal processing...

  15. Acquiring neural signals for developing a perception and cognition model

    Science.gov (United States)

    Li, Wei; Li, Yunyi; Chen, Genshe; Shen, Dan; Blasch, Erik; Pham, Khanh; Lynch, Robert

    2012-06-01

    The understanding of how humans process information, determine salience, and combine seemingly unrelated information is essential to automated processing of large amounts of information that is partially relevant, or of unknown relevance. Recent neurological science research in human perception, and in information science regarding contextbased modeling, provides us with a theoretical basis for using a bottom-up approach for automating the management of large amounts of information in ways directly useful for human operators. However, integration of human intelligence into a game theoretic framework for dynamic and adaptive decision support needs a perception and cognition model. For the purpose of cognitive modeling, we present a brain-computer-interface (BCI) based humanoid robot system to acquire brainwaves during human mental activities of imagining a humanoid robot-walking behavior. We use the neural signals to investigate relationships between complex humanoid robot behaviors and human mental activities for developing the perception and cognition model. The BCI system consists of a data acquisition unit with an electroencephalograph (EEG), a humanoid robot, and a charge couple CCD camera. An EEG electrode cup acquires brainwaves from the skin surface on scalp. The humanoid robot has 20 degrees of freedom (DOFs); 12 DOFs located on hips, knees, and ankles for humanoid robot walking, 6 DOFs on shoulders and arms for arms motion, and 2 DOFs for head yaw and pitch motion. The CCD camera takes video clips of the human subject's hand postures to identify mental activities that are correlated to the robot-walking behaviors. We use the neural signals to investigate relationships between complex humanoid robot behaviors and human mental activities for developing the perception and cognition model.

  16. Lateral specialization in unilateral spatial neglect: a cognitive robotics model.

    Science.gov (United States)

    Conti, Daniela; Di Nuovo, Santo; Cangelosi, Angelo; Di Nuovo, Alessandro

    2016-08-01

    In this paper, we present the experimental results of an embodied cognitive robotic approach for modelling the human cognitive deficit known as unilateral spatial neglect (USN). To this end, we introduce an artificial neural network architecture designed and trained to control the spatial attentional focus of the iCub robotic platform. Like the human brain, the architecture is divided into two hemispheres and it incorporates bio-inspired plasticity mechanisms, which allow the development of the phenomenon of the specialization of the right hemisphere for spatial attention. In this study, we validate the model by replicating a previous experiment with human patients affected by the USN and numerical results show that the robot mimics the behaviours previously exhibited by humans. We also simulated recovery after the damage to compare the performance of each of the two hemispheres as additional validation of the model. Finally, we highlight some possible advantages of modelling cognitive dysfunctions of the human brain by means of robotic platforms, which can supplement traditional approaches for studying spatial impairments in humans.

  17. CURRENT PROBLEMS OF DIAGNOSIS AND TREATMENT OF MILD COGNITIVE IMPAIRMENTS IN CHILDREN

    Directory of Open Access Journals (Sweden)

    G.A. Karkashadze

    2011-01-01

    Full Text Available In practical pediatrics specialists paid wrongly little attention to identification and treatment of cognitive disorders in children. At the same time it is difficult to overestimate the influence of cognitive functions on the formation of human personality and social maladjustment in this part of population. The paper is devoted to the diagnosis and treatment of cognitive impairments. In addition, the classification of this pathology, highlighting aetiopathogenetic factors, prognosis are showed. One of the important problems of early revealing of cognitive impairments and appropriate management of children with this pathology according to the authors opinion are the following: the deficiency of educational programs for training specialists in neurology, lack of knowledge concerning the possibilities of psychological-pedagogical correction, inefficient system of neurological techniques for primary care. Key words: cognitive function, mild cognitive impairment, classification, diagnosis, treatment, prognosis, social maladjustment, psychopedagogical support, children. (Pediatric Pharmacology. — 2011; 8 (5: 37–41.

  18. Machine Cognition Models: EPAM and GPS

    CERN Document Server

    Elouafiq, Ali

    2012-01-01

    Through history, the human being tried to relay its daily tasks to other creatures, which was the main reason behind the rise of civilizations. It started with deploying animals to automate tasks in the field of agriculture(bulls), transportation (e.g. horses and donkeys), and even communication (pigeons). Millenniums after, come the Golden age with "Al-jazari" and other Muslim inventors, which were the pioneers of automation, this has given birth to industrial revolution in Europe, centuries after. At the end of the nineteenth century, a new era was to begin, the computational era, the most advanced technological and scientific development that is driving the mankind and the reason behind all the evolutions of science; such as medicine, communication, education, and physics. At this edge of technology engineers and scientists are trying to model a machine that behaves the same as they do, which pushed us to think about designing and implementing "Things that-Thinks", then artificial intelligence was. In this...

  19. Cognitive endophenotypes, gene-environment interactions and experience-dependent plasticity in animal models of schizophrenia.

    Science.gov (United States)

    Burrows, Emma L; Hannan, Anthony J

    2016-04-01

    Schizophrenia is a devastating brain disorder caused by a complex and heterogeneous combination of genetic and environmental factors. In order to develop effective new strategies to prevent and treat schizophrenia, valid animal models are required which accurately model the disorder, and ideally provide construct, face and predictive validity. The cognitive deficits in schizophrenia represent some of the most debilitating symptoms and are also currently the most poorly treated. Therefore it is crucial that animal models are able to capture the cognitive dysfunction that characterizes schizophrenia, as well as the negative and psychotic symptoms. The genomes of mice have, prior to the recent gene-editing revolution, proven the most easily manipulable of mammalian laboratory species, and hence most genetic targeting has been performed using mouse models. Importantly, when key environmental factors of relevance to schizophrenia are experimentally manipulated, dramatic changes in the phenotypes of these animal models are often observed. We will review recent studies in rodent models which provide insight into gene-environment interactions in schizophrenia. We will focus specifically on environmental factors which modulate levels of experience-dependent plasticity, including environmental enrichment, cognitive stimulation, physical activity and stress. The insights provided by this research will not only help refine the establishment of optimally valid animal models which facilitate development of novel therapeutics, but will also provide insight into the pathogenesis of schizophrenia, thus identifying molecular and cellular targets for future preclinical and clinical investigations.

  20. Assessing the Cognitive Translational Potential of a Mouse Model of the 22q11.2 Microdeletion Syndrome.

    Science.gov (United States)

    Nilsson, Simon Ro; Fejgin, Kim; Gastambide, Francois; Vogt, Miriam A; Kent, Brianne A; Nielsen, Vibeke; Nielsen, Jacob; Gass, Peter; Robbins, Trevor W; Saksida, Lisa M; Stensbøl, Tine B; Tricklebank, Mark D; Didriksen, Michael; Bussey, Timothy J

    2016-10-01

    A chromosomal microdeletion at the 22q11.2 locus is associated with extensive cognitive impairments, schizophrenia and other psychopathology in humans. Previous reports indicate that mouse models of the 22q11.2 microdeletion syndrome (22q11.2DS) may model the genetic basis of cognitive deficits relevant for neuropsychiatric disorders such as schizophrenia. To assess the models usefulness for drug discovery, a novel mouse (Df(h22q11)/+) was assessed in an extensive battery of cognitive assays by partners within the NEWMEDS collaboration (Innovative Medicines Initiative Grant Agreement No. 115008). This battery included classic and touchscreen-based paradigms with recognized sensitivity and multiple attempts at reproducing previously published findings in 22q11.2DS mouse models. This work represents one of the most comprehensive reports of cognitive functioning in a transgenic animal model. In accordance with previous reports, there were non-significant trends or marginal impairment in some tasks. However, the Df(h22q11)/+ mouse did not show comprehensive deficits; no robust impairment was observed following more than 17 experiments and 14 behavioral paradigms. Thus - within the current protocols - the 22q11.2DS mouse model fails to mimic the cognitive alterations observed in human 22q11.2 deletion carriers. We suggest that the 22q11.2DS model may induce liability for cognitive dysfunction with additional "hits" being required for phenotypic expression. © The Author 2016. Published by Oxford University Press.

  1. Assessing the Cognitive Translational Potential of a Mouse Model of the 22q11.2 Microdeletion Syndrome

    Science.gov (United States)

    Nilsson, Simon RO.; Fejgin, Kim; Gastambide, Francois; Vogt, Miriam A.; Kent, Brianne A.; Nielsen, Vibeke; Nielsen, Jacob; Gass, Peter; Robbins, Trevor W.; Saksida, Lisa M.; Stensbøl, Tine B.; Tricklebank, Mark D.; Didriksen, Michael; Bussey, Timothy J.

    2016-01-01

    A chromosomal microdeletion at the 22q11.2 locus is associated with extensive cognitive impairments, schizophrenia and other psychopathology in humans. Previous reports indicate that mouse models of the 22q11.2 microdeletion syndrome (22q11.2DS) may model the genetic basis of cognitive deficits relevant for neuropsychiatric disorders such as schizophrenia. To assess the models usefulness for drug discovery, a novel mouse (Df(h22q11)/+) was assessed in an extensive battery of cognitive assays by partners within the NEWMEDS collaboration (Innovative Medicines Initiative Grant Agreement No. 115008). This battery included classic and touchscreen-based paradigms with recognized sensitivity and multiple attempts at reproducing previously published findings in 22q11.2DS mouse models. This work represents one of the most comprehensive reports of cognitive functioning in a transgenic animal model. In accordance with previous reports, there were non-significant trends or marginal impairment in some tasks. However, the Df(h22q11)/+ mouse did not show comprehensive deficits; no robust impairment was observed following more than 17 experiments and 14 behavioral paradigms. Thus – within the current protocols – the 22q11.2DS mouse model fails to mimic the cognitive alterations observed in human 22q11.2 deletion carriers. We suggest that the 22q11.2DS model may induce liability for cognitive dysfunction with additional “hits” being required for phenotypic expression. PMID:27507786

  2. Modelling relationships between cognitive variables during and following public speaking in participants with social phobia.

    Science.gov (United States)

    Rapee, Ronald M; Abbott, Maree J

    2007-12-01

    Cognitive models of social phobia predict that several cognitive processes will mediate the relationship between trait levels of social anxiety and the extent of anxiety experienced in a specific social-evaluative situation. The current study aimed to provide a test of these relationships. Over 200 clinical participants with social phobia completed measures of their general social anxiety and a week later performed a brief impromptu speech. They completed a measure of state anxiety in response to the speech as well as questionnaires assessing several cognitive constructs including focus of perceived attention, perceived performance, and probability and cost of negative evaluation. A week later, they completed measures of negative rumination experienced over the week, as well as a measure of the recollection of their perceived performance. Path analysis provided support for a model in which the cognitive factors mediated between general social anxiety and the degree of anxiety experienced in response to the speech. A second model supported the theory that negative rumination mediated between characteristic social anxiety and negative bias in the recollection of performance.

  3. Modeling media as latent semantics based on cognitive components

    DEFF Research Database (Denmark)

    Petersen, Michael Kai

    dimensionality. While top-down, patterns of emotional categorization emerge by defining term vector distances to affective adjectives, that constrain the latent semantic structures according to the neurophysiological dimensions of valence and arousal. The thesis thus combines elements of machine learning...... with aspects of cognitive linguistics that potentially could be utilized in applications ranging from information retrieval and media personalization, to emotional brand building or neuroscientific modeling of syntax and semantics....

  4. Current approaches to gene regulatory network modelling

    Directory of Open Access Journals (Sweden)

    Brazma Alvis

    2007-09-01

    Full Text Available Abstract Many different approaches have been developed to model and simulate gene regulatory networks. We proposed the following categories for gene regulatory network models: network parts lists, network topology models, network control logic models, and dynamic models. Here we will describe some examples for each of these categories. We will study the topology of gene regulatory networks in yeast in more detail, comparing a direct network derived from transcription factor binding data and an indirect network derived from genome-wide expression data in mutants. Regarding the network dynamics we briefly describe discrete and continuous approaches to network modelling, then describe a hybrid model called Finite State Linear Model and demonstrate that some simple network dynamics can be simulated in this model.

  5. Cognition and procedure representational requirements for predictive human performance models

    Science.gov (United States)

    Corker, K.

    1992-01-01

    Models and modeling environments for human performance are becoming significant contributors to early system design and analysis procedures. Issues of levels of automation, physical environment, informational environment, and manning requirements are being addressed by such man/machine analysis systems. The research reported here investigates the close interaction between models of human cognition and models that described procedural performance. We describe a methodology for the decomposition of aircrew procedures that supports interaction with models of cognition on the basis of procedures observed; that serves to identify cockpit/avionics information sources and crew information requirements; and that provides the structure to support methods for function allocation among crew and aiding systems. Our approach is to develop an object-oriented, modular, executable software representation of the aircrew, the aircraft, and the procedures necessary to satisfy flight-phase goals. We then encode in a time-based language, taxonomies of the conceptual, relational, and procedural constraints among the cockpit avionics and control system and the aircrew. We have designed and implemented a goals/procedures hierarchic representation sufficient to describe procedural flow in the cockpit. We then execute the procedural representation in simulation software and calculate the values of the flight instruments, aircraft state variables and crew resources using the constraints available from the relationship taxonomies. The system provides a flexible, extensible, manipulative and executable representation of aircrew and procedures that is generally applicable to crew/procedure task-analysis. The representation supports developed methods of intent inference, and is extensible to include issues of information requirements and functional allocation. We are attempting to link the procedural representation to models of cognitive functions to establish several intent inference methods

  6. Cognitive load theory and multimedia learning, task characteristics, and learning engagement: The current state of the art

    NARCIS (Netherlands)

    Kirschner, Femke; Kester, Liesbeth; Corbalan, Gemma

    2010-01-01

    Kirschner, F., Kester, L., & Corbalan, G. (2011). Cognitive load theory and multimedia learning, task characteristics, and learner engagement: The current state of the art. Computers in Human Behavior, 27, 1-4. doi:10.1016/j.chb.2010.05.003

  7. Cognitive load theory and multimedia learning, task characteristics, and learning engagement: The current state of the art

    NARCIS (Netherlands)

    Kirschner, Femke; Kester, Liesbeth; Corbalan, Gemma

    2010-01-01

    Kirschner, F., Kester, L., & Corbalan, G. (2011). Cognitive load theory and multimedia learning, task characteristics, and learner engagement: The current state of the art. Computers in Human Behavior, 27, 1-4. doi:10.1016/j.chb.2010.05.003

  8. Does the cognitive reflection test measure cognitive reflection? A mathematical modeling approach.

    Science.gov (United States)

    Campitelli, Guillermo; Gerrans, Paul

    2014-04-01

    We used a mathematical modeling approach, based on a sample of 2,019 participants, to better understand what the cognitive reflection test (CRT; Frederick In Journal of Economic Perspectives, 19, 25-42, 2005) measures. This test, which is typically completed in less than 10 min, contains three problems and aims to measure the ability or disposition to resist reporting the response that first comes to mind. However, since the test contains three mathematically based problems, it is possible that the test only measures mathematical abilities, and not cognitive reflection. We found that the models that included an inhibition parameter (i.e., the probability of inhibiting an intuitive response), as well as a mathematical parameter (i.e., the probability of using an adequate mathematical procedure), fitted the data better than a model that only included a mathematical parameter. We also found that the inhibition parameter in males is best explained by both rational thinking ability and the disposition toward actively open-minded thinking, whereas in females this parameter was better explained by rational thinking only. With these findings, this study contributes to the understanding of the processes involved in solving the CRT, and will be particularly useful for researchers who are considering using this test in their research.

  9. Mindfulness-based cognitive therapy for recurrent depression: Do we need to exclude currently depressed patients?

    NARCIS (Netherlands)

    Aalderen, J.R. van

    2016-01-01

    For many patients, major depression is a recurrent disorder and a potential chronic disease causing significant levels of distress. Mindfulness-based cognitive therapy (MBCT) is an 8-week training combining meditation exercises and cognitive therapy aimed at preventing relapse in patients with remi

  10. Exploring the cognitive and motor functions of the basal ganglia: An integrative review of computational cognitive neuroscience models

    Directory of Open Access Journals (Sweden)

    Sebastien eHelie

    2013-12-01

    Full Text Available Many computational models of the basal ganglia have been proposed over the past twenty-five years. While computational neuroscience models have focused on closely matching the neurobiology of the basal ganglia, computational cognitive neuroscience models have focused on how the basal ganglia can be used to implement cognitive and motor functions. This review article focuses on computational cognitive neuroscience models of the basal ganglia and how they use the neuroanatomy of the basal ganglia to account for cognitive and motor functions such as categorization, instrumental conditioning, probabilistic learning, working memory, sequence learning, automaticity, reaching, handwriting, and eye saccades. A total of 19 basal ganglia models accounting for one or more of these functions are reviewed and compared. The review concludes with a discussion of the limitations of existing computational cognitive neuroscience models of the basal ganglia and prescriptions for future modeling, including the need for computational models of the basal ganglia that can simultaneously account for cognitive and motor functions, and the need for a more complete specification of the role of the basal ganglia in behavioral functions.

  11. High Performance Computing for Agent-Based Cognitive Modeling

    Science.gov (United States)

    2011-02-25

    2.2.2.2 EX2 and EX3 Agents - ACT-R A simple agent was developed by Jaehyon Paik using the LISP -based ACT-R cognitive framework. Unlike the EX1...current user, and connecting the new one to the same account. 5 Both of these issues were overcome by generating pieces of the agent LISP code during...on a single local machine. The Fenrir VM was used to host the environment. Versions of MPI (MPICH2), and LISP (Clozure LISP ) that are available on

  12. Applying the Cognitive Vulnerability Model to the analysis of cognitive and family influences on children's dental fear.

    Science.gov (United States)

    Crego, Antonio; Carrillo-Diaz, Maria; Armfield, Jason M; Romero, Martin

    2013-06-01

    Negative experiences, cognitions, and family variables are involved in the etiology of child dental fear, but previous research has frequently considered them separately. This study uses the Cognitive Vulnerability Model to explore the influence of negative dental experiences and family members on children's dental anxiety. The participants were 185 children who completed a questionnaire comprising measures of dental fear and cognitive vulnerability-related perceptions. Measures were obtained for 88 of the participants' fathers and for 97 of the participants' mothers. Cognitive vulnerability perceptions had the strongest association with children's dental fear (β = 0.40), explaining 14-21% of the variance in dental fear scores beyond that explained by other variables. Furthermore, vulnerability perceptions mediated the relationship between negative dental experiences and dental fear. Children's dental fear and cognitive vulnerability perceptions were significantly associated with those of their fathers (r = 0.23 and r = 0.40, respectively) and mothers (r = 0.28 and r = 0.35, respectively). Moreover, fathers' (β = 0.24) and mothers' (β = 0.31) levels of cognitive vulnerability significantly predicted the children's levels of dental fear. The Cognitive Vulnerability Model offers a framework to understand child dental fear. Furthermore, this cognitive approach may help explain why some children develop dental fear problems after suffering a negative dental experience and how dental anxiety is passed on from parents to children.

  13. Relationship Marketing results: proposition of a cognitive mapping model

    Directory of Open Access Journals (Sweden)

    Iná Futino Barreto

    2015-12-01

    Full Text Available Objective - This research sought to develop a cognitive model that expresses how marketing professionals understand the relationship between the constructs that define relationship marketing (RM. It also tried to understand, using the obtained model, how objectives in this field are achieved. Design/methodology/approach – Through cognitive mapping, we traced 35 individual mental maps, highlighting how each respondent understands the interactions between RM elements. Based on the views of these individuals, we established an aggregate mental map. Theoretical foundation – The topic is based on a literature review that explores the RM concept and its main elements. Based on this review, we listed eleven main constructs. Findings – We established an aggregate mental map that represents the RM structural model. Model analysis identified that CLV is understood as the final result of RM. We also observed that the impact of most of the RM elements on CLV is brokered by loyalty. Personalization and quality, on the other hand, proved to be process input elements, and are the ones that most strongly impact others. Finally, we highlight that elements that punish customers are much less effective than elements that benefit them. Contributions - The model was able to insert core elements of RM, but absent from most formal models: CLV and customization. The analysis allowed us to understand the interactions between the RM elements and how the end result of RM (CLV is formed. This understanding improves knowledge on the subject and helps guide, assess and correct actions.

  14. Embodying cognition

    DEFF Research Database (Denmark)

    Martiny, Kristian Møller Moltke; Aggerholm, Kenneth

    2016-01-01

    During the last decades, research on cognition has undergone a reformation, which is necessary to take into account when evaluating the cognitive and behavioural aspects of therapy. This reformation is due to the research programme called Embodied Cognition (EC). Although EC may have become...... the theoretical authority in current cognitive science, there are only sporadic examples of EC-based therapy, and no established framework. We aim to build such a framework on the aims, methods and techniques of the current third-wave of CBT. There appears to be a possibility for cross-fertilization between EC...... and CBT that could contribute to the development of theory and practice for both of them. We present a case-study of an EC-based model of intervention for working with self-control in cerebral palsy.We centre the results of the study and its discussion on how we should understand and work with self...

  15. Calculus for cognitive scientists derivatives, integrals and models

    CERN Document Server

    Peterson, James K

    2016-01-01

    This book provides a self-study program on how mathematics, computer science and science can be usefully and seamlessly intertwined. Learning to use ideas from mathematics and computation is essential for understanding approaches to cognitive and biological science. As such the book covers calculus on one variable and two variables and works through a number of interesting first-order ODE models. It clearly uses MatLab in computational exercises where the models cannot be solved by hand, and also helps readers to understand that approximations cause errors – a fact that must always be kept in mind.

  16. The Effects of Exercise on Cognitive Recovery after Acquired Brain Injury in Animal Models

    DEFF Research Database (Denmark)

    Wogensen, Elise; Rytter, Hana Malá; Mogensen, Jesper

    2015-01-01

    The objective of the present paper is to review the current status of exercise as a tool to promote cognitive rehabilitation after acquired brain injury (ABI) in animal model-based research. Searches were conducted on the PubMed, Scopus, and psycINFO databases in February 2014. Search strings used...... were: exercise (and) animal model (or) rodent (or) rat (and) traumatic brain injury (or) cerebral ischemia (or) brain irradiation. Studies were selected if they were (1) in English, (2) used adult animals subjected to acquired brain injury, (3) used exercise as an intervention tool after inflicted...... injury, (4) used exercise paradigms demanding movement of all extremities, (5) had exercise intervention effects that could be distinguished from other potential intervention effects, and (6) contained at least one measure of cognitive and/or emotional function. Out of 2308 hits, 22 publications...

  17. Symptom severity of depressive symptoms impacts on social cognition performance in current but not remitted major depressive disorder.

    Science.gov (United States)

    Air, Tracy; Weightman, Michael J; Baune, Bernhard T

    2015-01-01

    The aim of the present study was to investigate the social cognitive functioning of participants with depression when compared with healthy controls, and to assess the impact of symptom severity. One hundred and eight patients with depression (66 remitted and 42 current) and 52 healthy controls were assessed using the Wechsler Advanced Clinical Solutions: Social Perception Subtest, measuring facial affect recognition in isolation and in combination with prosody and body language interpretation. When healthy controls, remitted depression and currently depressed groups were compared, no associations were found on any of the social cognition subscales. Severity of depressive and anxious symptoms predicted performance on all social cognition subscales in currently depressed participants, controlling for age, gender, education and psychotropic medication. Affective depressive symptoms were inversely related to ACS Pairs and Prosody subscales, while somatic symptoms were inversely related to the ACS Affect Recognition and Total scores. There was no association between severity and the WAIS ACS in remitted depression participants. People with MDD exhibiting more severe depressive and anxious symptoms and a cluster of affective symptoms have greater difficulty undertaking complex social cognitive tasks. Given the state like nature to these deficits, these impairments may cause problems with day to day functioning and have implications in targeted therapeutic interventions.

  18. Symptom severity, affective and somatic symptom clusters predict poorer social cognition performance in current but not remitted major depressive disorder

    Directory of Open Access Journals (Sweden)

    Tracy eAir

    2015-08-01

    Full Text Available The aim of the study was to investigate the social cognitive functioning of participants with major depressive disorder when compared with healthy controls, and to assess the impact of symptom severity and affective and somatic symptom clusters on social cognition. One hundred and eight adult patients with depression (66 remitted and 42 current and 52 healthy controls were assessed using the Wechsler Advanced Clinical Solutions: Social Perception Subtest, measuring facial affect recognition in isolation and in combination with prosody and body language interpretation. While no associations between the diagnostic status (MDD vs controls and any of the social cognition measures were found, severity of depressive and anxious symptoms predicted performance on all social cognition subscales in currently depressed participants, controlling for age, gender, education and psychotropic medication. Moreover, in the current MDD group, an affective depressive symptom cluster was inversely related to performance on the more complex ACS Pairs and Prosody tasks, while a somatic symptom cluster was inversely related to ACS Affect Recognition and Total scores. In contrast, there were no associations between symptom severity or symptom clusters and the WAIS ACS in remitted depression participants. Given the state like nature social deficits in this study, these impairments may cause problems with day to day functioning and have implications in targeted therapeutic interventions.

  19. Current trends in the empirical study of cognitive remediation for schizophrenia.

    Science.gov (United States)

    Saperstein, Alice M; Kurtz, Matthew M

    2013-06-01

    Cognitive remediation (CR) for schizophrenia is a learning-based behavioural skills training intervention designed to enhance neuro and (or) social cognitive skills, with the ultimate goal of generalization to improve psychosocial outcomes. This review summarizes conceptual approaches to CR for schizophrenia and the evidence for efficacy in clinical research settings. Four issues are at the forefront of ongoing research: the identification of techniques that produce the largest cognitive change, delineation of techniques that enhance transfer of cognitive skills to functional skills, the identification of CR methods that can be personalized to meet the specific cognitive and functional needs of each individual, and, all the while, ensuring that when CR methods are developed in a research setting, they remain scalable for delivery in the larger clinical community. In response to these issues, 3 prominent research trends have emerged: the rise of a new generation of computerized restorative cognitive training, the integration of CR with skills training to promote generalization, and the application of techniques to enhance motivation and learning during CR. As data on the neural basis of learning in people with schizophrenia become available, new technologies that harness the ability of the brain to make sustainable, functional changes may be integrated within a therapeutic context that promotes a personalized approach to learning. The development of transportable and scalable methods of CR that maximize the ability of people with schizophrenia to improve cognition will help them achieve personal goals for recovery.

  20. Structural Equation Modeling of the Effects of Family, Preschool, and Stunting on the Cognitive Development of School Children

    Science.gov (United States)

    Ajayi, Oluwakemi Rachel; Matthews, Glenda Beverley; Taylor, Myra; Kvalsvig, Jane Dene; Davidson, Leslie; Kauchali, Shuaib; Mellins, Claude

    2017-01-01

    A recent study based on a sample of 1,580 children from five adjacent geographical locations in KwaZulu-Natal, South Africa, was carried out to examine the association of nutrition, family influence, preschool education, and disadvantages in geographical location with the cognitive development of school children. Data were collected on the children from 2009 to 2011 for this developmental study and included cognitive scores and information on the health and nutrition of the children. The current study analyzed the association of demographic variables (geographical location (site)), child variables (sex, preschool education and socioeconomic status), parental level of education (maternal and paternal), child’s health (HIV status and hemoglobin level) and anthropometric measures of nutritional status (height-for-age) with children’s cognitive outcomes. The hypothesis is that the nutritional status of children is a pathway through which the indirect effects of the variables of interest exert influence on their cognitive outcomes. Factor analysis based on principal components was used to create a variable based on the cognitive measures, correlations were used to examine the bivariate association between the variables of interest in the preliminary analysis and a path analysis was constructed, which was used for the disaggregation of the direct and indirect effects of the predictors for each cognitive test in a structural equation model. The results revealed that nutritional status directly predicts cognitive test scores and is a path through which other variables indirectly influence children’s cognitive outcome and development. PMID:28555186

  1. Structural Equation Modeling of the Effects of Family, Preschool, and Stunting on the Cognitive Development of School Children

    Directory of Open Access Journals (Sweden)

    Oluwakemi Rachel Ajayi

    2017-05-01

    Full Text Available A recent study based on a sample of 1,580 children from five adjacent geographical locations in KwaZulu-Natal, South Africa, was carried out to examine the association of nutrition, family influence, preschool education, and disadvantages in geographical location with the cognitive development of school children. Data were collected on the children from 2009 to 2011 for this developmental study and included cognitive scores and information on the health and nutrition of the children. The current study analyzed the association of demographic variables (geographical location (site, child variables (sex, preschool education and socioeconomic status, parental level of education (maternal and paternal, child’s health (HIV status and hemoglobin level and anthropometric measures of nutritional status (height-for-age with children’s cognitive outcomes. The hypothesis is that the nutritional status of children is a pathway through which the indirect effects of the variables of interest exert influence on their cognitive outcomes. Factor analysis based on principal components was used to create a variable based on the cognitive measures, correlations were used to examine the bivariate association between the variables of interest in the preliminary analysis and a path analysis was constructed, which was used for the disaggregation of the direct and indirect effects of the predictors for each cognitive test in a structural equation model. The results revealed that nutritional status directly predicts cognitive test scores and is a path through which other variables indirectly influence children’s cognitive outcome and development.

  2. Genetic spectrum assignment model with constraints in cognitive radio networks

    Directory of Open Access Journals (Sweden)

    Fang Ye

    2011-06-01

    Full Text Available The interference constraints of genetic spectrum assignment model in cognitive radio networks are analyzed in this paper. An improved genetic spectrum assignment model is proposed. The population of genetic algorithm is divided into two sets, the feasible spectrum assignment strategies and the randomly updated spectrum assignment strategies. The penalty function is added to the utility function to achieve the spectrum assignment strategy that satisfies the interference constraints and has better fitness. The proposed method is applicable in both the genetic spectrum assignment model and the quantum genetic spectrum assignment mode. It can ensure the randomness of partial chromosomes in the population to some extent, and reduce the computational complexity caused by the constraints-free procedure after the update of population. Simulation results show that the proposed method can achieve better performance than the conventional genetic spectrum assignment model and quantum genetic spectrum assignment model

  3. Modeling the situation awareness by the analysis of cognitive process.

    Science.gov (United States)

    Liu, Shuang; Wanyan, Xiaoru; Zhuang, Damin

    2014-01-01

    To predict changes of situation awareness (SA) for pilot operating with different display interfaces and tasks, a qualitative analysis and quantitative calculation joint SA model was proposed. Based on the situational awareness model according to the attention allocation built previously, the pilot cognitive process for the situation elements was analyzed according to the ACT-R (Adaptive Control of Thought, Rational) theory, which explained how the SA was produced. To verify the validity of this model, 28 subjects performed an instrument supervision task under different experiment conditions. Situation Awareness Global Assessment Technique (SAGAT), 10-dimensional Situational Awareness Rating Technique (10-D SART), performance measure and eye movement measure were adopted for evaluating SAs under different conditions. Statistical analysis demonstrated that the changing trend of SA calculated by this model was highly correlated with the experimental results. Therefore the situational awareness model can provide a reference for designing new cockpit display interfaces and help reducing human errors.

  4. Current status: Animal models of nausea

    Science.gov (United States)

    Fox, Robert A.

    1991-01-01

    The advantages, and possible benefits of a valid, reliable animal model for nausea are discussed, and difficulties inherent to the development of a model are considered. A principle problem for developing models arises because nausea is a subjective sensation that can be identified only in humans. Several putative measures of nausea in animals are considered, with more detailed consideration directed to variation in cardiac rate, levels of vasopressin, and conditioned taste aversion. Demonstration that putative measures are associated with reported nausea in humans is proposed as a requirement for validating measures to be used in animal models. The necessity for a 'real-time' measure of nausea is proposed as an important factor for future research; and the need for improved understanding of the neuroanatomy underlying the emetic syndrome is discussed.

  5. Current status of cosmological MDM model

    CERN Document Server

    Mikheeva, E V; Arkhipova, N A; Malinovsky, A M

    2000-01-01

    An analysis of cosmological models in spatially flat Friedmann Universe with cosmic gravitational wave background and zero $\\Lambda$-term is presented. The number of free parameters is equal to 5, they are $\\sigma_8$, $n$, $\\Omega_\

  6. Surface CUrrents from a Diagnostic model (SCUD): Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SCUD data product is an estimate of upper-ocean velocities computed from a diagnostic model (Surface CUrrents from a Diagnostic model). This model makes daily...

  7. Human performance cognitive-behavioral modeling: a benefit for occupational safety

    Science.gov (United States)

    Gore, Brian F.

    2002-01-01

    Human Performance Modeling (HPM) is a computer-aided job analysis software methodology used to generate predictions of complex human-automation integration and system flow patterns with the goal of improving operator and system safety. The use of HPM tools has recently been increasing due to reductions in computational cost, augmentations in the tools' fidelity, and usefulness in the generated output. An examination of an Air Man-machine Integration Design and Analysis System (Air MIDAS) model evaluating complex human-automation integration currently underway at NASA Ames Research Center will highlight the importance to occupational safety of considering both cognitive and physical aspects of performance when researching human error.

  8. Current theoretical models of generalized anxiety disorder (GAD): conceptual review and treatment implications.

    Science.gov (United States)

    Behar, Evelyn; DiMarco, Ilyse Dobrow; Hekler, Eric B; Mohlman, Jan; Staples, Alison M

    2009-12-01

    Theoretical conceptualizations of generalized anxiety disorder (GAD) continue to undergo scrutiny and refinement. The current paper critiques five contemporary models of GAD: the Avoidance Model of Worry and GAD [Borkovec, T. D. (1994). The nature, functions, and origins of worry. In: G. Davey & F. Tallis (Eds.), Worrying: perspectives on theory assessment and treatment (pp. 5-33). Sussex, England: Wiley & Sons; Borkovec, T. D., Alcaine, O. M., & Behar, E. (2004). Avoidance theory of worry and generalized anxiety disorder. In: R. Heimberg, C. Turk, & D. Mennin (Eds.), Generalized anxiety disorder: advances in research and practice (pp. 77-108). New York, NY, US: Guilford Press]; the Intolerance of Uncertainty Model [Dugas, M. J., Letarte, H., Rheaume, J., Freeston, M. H., & Ladouceur, R. (1995). Worry and problem solving: evidence of a specific relationship. Cognitive Therapy and Research, 19, 109-120; Freeston, M. H., Rheaume, J., Letarte, H., Dugas, M. J., & Ladouceur, R. (1994). Why do people worry? Personality and Individual Differences, 17, 791-802]; the Metacognitive Model [Wells, A. (1995). Meta-cognition and worry: a cognitive model of generalized anxiety disorder. Behavioural and Cognitive Psychotherapy, 23, 301-320]; the Emotion Dysregulation Model [Mennin, D. S., Heimberg, R. G., Turk, C. L., & Fresco, D. M. (2002). Applying an emotion regulation framework to integrative approaches to generalized anxiety disorder. Clinical Psychology: Science and Practice, 9, 85-90]; and the Acceptance-based Model of GAD [Roemer, L., & Orsillo, S. M. (2002). Expanding our conceptualization of and treatment for generalized anxiety disorder: integrating mindfulness/acceptance-based approaches with existing cognitive behavioral models. Clinical Psychology: Science and Practice, 9, 54-68]. Evidence in support of each model is critically reviewed, and each model's corresponding evidence-based therapeutic interventions are discussed. Generally speaking, the models share an

  9. CURRENT ISSUES IN DIAGNOSIS AND TREATMENT OF COGNITIVE DISORDERS IN CHILDREN WITH CEREBRAL PALSY

    Directory of Open Access Journals (Sweden)

    S. A. Nemkova

    2012-01-01

    Full Text Available The article covers in detail the problems of diagnosis and treatment of cognitive impairment in children with cerebral palsy. Diagnosis of cognitive disorders, cerebral palsy is a challenging task, due to various combinations of these disorders with physical, speech and sensory disorders, which requires a differentiated approach. The authors have developed a differential-diagnostic criteria to distinguish between impaired mental function and mental retardation with cerebral palsy, as well as the proposed comprehensive system of rehabilitation of cognitive disorders, including medical and social, and psychological-pedagogical correction, which is aimed at compensating for cognitive deficits, the formation of mental functions, and the restoration of the mechanisms of social integration of children with cerebral palsy.

  10. Type 2 diabetes as a risk factor for cognitive impairment: current insights

    Directory of Open Access Journals (Sweden)

    Umegaki H

    2014-06-01

    Full Text Available Hiroyuki Umegaki Department of Community Healthcare and Geriatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan Abstract: Type 2 diabetes mellitus (T2DM is a risk factor for cognitive dysfunction and dementia in the elderly. T2DM has been thought to be associated with vascular diseases, eventually leading to vascular dementia, but recent studies have established that T2DM is also associated with Alzheimer’s disease (AD. With the increase in the number of elderly individuals with T2DM, the number of diabetic patients with cognitive dysfunction has been increasing. T2DM may accelerate AD-associated pathologies through insulin resistance. Vascular pathologies may also be associated with cognitive dysfunction and dementia in T2DM subjects. Several other mechanisms also seem to be involved in T2DM-related cognitive dysfunction. More investigations to clarify the association of T2DM with cognitive impairment are warranted. These investigations may help to increase our understanding of AD and open a new door to the development of therapeutics. Recent pharmaceutical advancement in T2DM treatment has resulted in the availability of a wide range of antidiabetics. Some evidence has suggested that antidiabetic therapies help to prevent cognitive dysfunction. At present, however, the optimal level of blood glucose control and the best combination of medications to achieve it in terms of cognitive preservation have not been established. More investigation is warranted. Cognitive dysfunction is an emerging new complication of T2DM that requires further study. Keywords: insulin resistance, dementia, blood glucose, amyloid ß, tau, small vascular disease

  11. Cholinergic modulation of cognitive processing: insights drawn from computational models

    Directory of Open Access Journals (Sweden)

    Ehren L Newman

    2012-06-01

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

  12. Cognitive load and modelling of an algebra problem

    Science.gov (United States)

    Chinnappan, Mohan

    2010-09-01

    In the present study, I examine a modelling strategy as employed by a teacher in the context of an algebra lesson. The actions of this teacher suggest that a modelling approach will have a greater impact on enriching student learning if we do not lose sight of the need to manage associated cognitive loads that could either aid or hinder the integration of core concepts with processes that are at play. Results here also show that modelling a problem that is set within an authentic context helps learners develop a better appreciation of variables and relations that constitute the model. The teacher's scaffolding actions revealed the use of strategies that foster the development of connected, meaningful and more useable algebraic knowledge.

  13. Current Density and Continuity in Discretized Models

    Science.gov (United States)

    Boykin, Timothy B.; Luisier, Mathieu; Klimeck, Gerhard

    2010-01-01

    Discrete approaches have long been used in numerical modelling of physical systems in both research and teaching. Discrete versions of the Schrodinger equation employing either one or several basis functions per mesh point are often used by senior undergraduates and beginning graduate students in computational physics projects. In studying…

  14. Imaging a cognitive model of apraxia: the neural substrate of gesture-specific cognitive processes.

    Science.gov (United States)

    Peigneux, Philippe; Van der Linden, Martial; Garraux, Gaetan; Laureys, Steven; Degueldre, Christian; Aerts, Joel; Del Fiore, Guy; Moonen, Gustave; Luxen, Andre; Salmon, Eric

    2004-03-01

    The present study aimed to ascertain the neuroanatomical basis of an influential neuropsychological model for upper limb apraxia [Rothi LJ, et al. The Neuropsychology of Action. 1997. Hove, UK: Psychology Press]. Regional cerebral blood flow was measured in healthy volunteers using H2 15O PET during performance of four tasks commonly used for testing upper limb apraxia, i.e., pantomime of familiar gestures on verbal command, imitation of familiar gestures, imitation of novel gestures, and an action-semantic task that consisted in matching objects for functional use. We also re-analysed data from a previous PET study in which we investigated the neural basis of the visual analysis of gestures. First, we found that two sets of discrete brain areas are predominantly engaged in the imitation of familiar and novel gestures, respectively. Segregated brain activation for novel gesture imitation concur with neuropsychological reports to support the hypothesis that knowledge about the organization of the human body mediates the transition from visual perception to motor execution when imitating novel gestures [Goldenberg Neuropsychologia 1995;33:63-72]. Second, conjunction analyses revealed distinctive neural bases for most of the gesture-specific cognitive processes proposed in this cognitive model of upper limb apraxia. However, a functional analysis of brain imaging data suggested that one single memory store may be used for "to-be-perceived" and "to-be-produced" gestural representations, departing from Rothi et al.'s proposal. Based on the above considerations, we suggest and discuss a revised model for upper limb apraxia that might best account for both brain imaging findings and neuropsychological dissociations reported in the apraxia literature. Copyright 2004 Wiley-Liss, Inc.

  15. Cognitive wireless networks

    CERN Document Server

    Feng, Zhiyong; Zhang, Ping

    2015-01-01

    This brief examines the current research in cognitive wireless networks (CWNs). Along with a review of challenges in CWNs, this brief presents novel theoretical studies and architecture models for CWNs, advances in the cognitive information awareness and delivery, and intelligent resource management technologies. The brief presents the motivations and concepts of CWNs, including theoretical studies of temporal and geographic distribution entropy as well as cognitive information metrics. A new architecture model of CWNs is proposed with theoretical, functional and deployment architectures suppo

  16. Cognitive rehabilitation reduces cognitive impairment and normalizes hippocampal CA1 architecture in a rat model of vascular dementia.

    Science.gov (United States)

    Langdon, Kristopher D; Granter-Button, Shirley; Harley, Carolyn W; Moody-Corbett, Frances; Peeling, James; Corbett, Dale

    2013-06-01

    Dementia is a major cause of morbidity in the western society. Pharmacological therapies to delay the progression of cognitive impairments are modestly successful. Consequently, new therapies are urgently required to improve cognitive deficits associated with dementia. We evaluated the effects of physical and cognitive activity on learning and memory in a rat model of vascular dementia (VasD). Male Sprague-Dawley rats (6 months old) were exposed to either regular chow or a diet rich in saturated fats and sucrose and chronic bilateral common carotid artery occlusion or sham surgery. First, this model of VasD was validated using a 2 × 2 experimental design (surgery × diet) and standard cognitive outcomes. Next, using identical surgical procedures, we exposed animals to a paradigm of cognitive rehabilitation or a sedentary condition. At 16 weeks post surgery, VasD animals demonstrated significant learning and memory deficits in the Morris water maze, independent of diet. Rehabilitation significantly attenuated these cognitive deficits at this time point as well as at 24 weeks. Further, rehabilitation normalized hippocampal CA1 soma size (area and volume) to that of control animals, independent of cell number. Importantly, these findings demonstrate beneficial neuroplasticity in early middle-aged rats that promoted cognitive recovery, an area rarely explored in preclinical studies.

  17. Models of Solar Irradiance Variations: Current Status

    Indian Academy of Sciences (India)

    Natalie A. Krivova; Sami K. Solanki

    2008-03-01

    Regular monitoring of solar irradiance has been carried out since 1978 to show that solar total and spectral irradiance varies at different time scales. Whereas variations on time scales of minutes to hours are due to solar oscillations and granulation, variations on longer time scales are driven by the evolution of the solar surface magnetic field. Here the most recent advances in modelling of solar irradiance variations on time scales longer than a day are briefly reviewed.

  18. Using data-driven model-brain mappings to constrain formal models of cognition.

    Directory of Open Access Journals (Sweden)

    Jelmer P Borst

    Full Text Available In this paper we propose a method to create data-driven mappings from components of cognitive models to brain regions. Cognitive models are notoriously hard to evaluate, especially based on behavioral measures alone. Neuroimaging data can provide additional constraints, but this requires a mapping from model components to brain regions. Although such mappings can be based on the experience of the modeler or on a reading of the literature, a formal method is preferred to prevent researcher-based biases. In this paper we used model-based fMRI analysis to create a data-driven model-brain mapping for five modules of the ACT-R cognitive architecture. We then validated this mapping by applying it to two new datasets with associated models. The new mapping was at least as powerful as an existing mapping that was based on the literature, and indicated where the models were supported by the data and where they have to be improved. We conclude that data-driven model-brain mappings can provide strong constraints on cognitive models, and that model-based fMRI is a suitable way to create such mappings.

  19. Sparse multivariate autoregressive modeling for mild cognitive impairment classification.

    Science.gov (United States)

    Li, Yang; Wee, Chong-Yaw; Jie, Biao; Peng, Ziwen; Shen, Dinggang

    2014-07-01

    Brain connectivity network derived from functional magnetic resonance imaging (fMRI) is becoming increasingly prevalent in the researches related to cognitive and perceptual processes. The capability to detect causal or effective connectivity is highly desirable for understanding the cooperative nature of brain network, particularly when the ultimate goal is to obtain good performance of control-patient classification with biological meaningful interpretations. Understanding directed functional interactions between brain regions via brain connectivity network is a challenging task. Since many genetic and biomedical networks are intrinsically sparse, incorporating sparsity property into connectivity modeling can make the derived models more biologically plausible. Accordingly, we propose an effective connectivity modeling of resting-state fMRI data based on the multivariate autoregressive (MAR) modeling technique, which is widely used to characterize temporal information of dynamic systems. This MAR modeling technique allows for the identification of effective connectivity using the Granger causality concept and reducing the spurious causality connectivity in assessment of directed functional interaction from fMRI data. A forward orthogonal least squares (OLS) regression algorithm is further used to construct a sparse MAR model. By applying the proposed modeling to mild cognitive impairment (MCI) classification, we identify several most discriminative regions, including middle cingulate gyrus, posterior cingulate gyrus, lingual gyrus and caudate regions, in line with results reported in previous findings. A relatively high classification accuracy of 91.89 % is also achieved, with an increment of 5.4 % compared to the fully-connected, non-directional Pearson-correlation-based functional connectivity approach.

  20. Dynamic simulation of sustainable farm development scenarios using cognitive modeling

    Directory of Open Access Journals (Sweden)

    Tuzhyk Kateryna

    2017-03-01

    Full Text Available Dynamic simulation of sustainable farm development scenarios using cognitive modeling. The paper presents a dynamic simulation system of sustainable development scenarios on farms using cognitive modeling. The system incorporates relevant variables which affect the sustainable development of farms. Its user provides answers to strategic issues connected with the level of farm sustainability over a long-term perspective of dynamic development. The work contains a description of the model structure as well as the results of simulations carried out on 16 farms in northern Ukraine. The results show that the process of sustainability is based mainly on the potential for innovation in agricultural production and biodiversity. The user is able to simulate various scenarios for the sustainable development of a farm and visualize the influence of factors on the economic and social situation, as well as on environmental aspects. Upon carrying out a series of simulations, it was determined that the development of farms characterized by sustainable development is based on additional profit, which serves as the main motivation for transforming a conventional farm into a sustainable one. Nevertheless, additional profit is not the only driving force in the system of sustainable development. The standard of living, market condition, and legal regulations as well as government support also play a significant motivational role.

  1. A Cognitive Modeling Method of the Life Quality Indicators in Terms of External Factors

    Directory of Open Access Journals (Sweden)

    L. V. Massel

    2016-01-01

    Full Text Available The article discusses a potential use of the methods of cognitive modeling in the field of quality of life. The quality of life, as a universal indicator of human self-perception to feel his sense of satisfaction from various parts of his life, is difficult to assess by strictly mathematical methods, so the authors suggest using the cognitive modeling. The quality of life in his estimation for the convenience of research activity is divided into components - indicators of the quality of life. The widespread indicator "quality of life" and the complexity of the development of its assessment methods lead to high relevance of the authors-proposed method.The introduction provides an overview of current approaches to assessing the quality of life. Among all these approaches the most advantageous is an objectively subjective one. The paper gives a brief assessment of cognitive modeling methods, which are, essentially, a way of graphic and structural elements of reflection and relationships in complex systems. As a result of the analysis of existing research in this area, was found the potential for creating cognitive models of the quality of life and its indicators and was defined the place of the proposed method, among others. The paper presents the method itself, as a series of steps, and focuses on the promising opportunities for researchers of the quality of life from its using.Among the possible lines to use cognitive modeling of the life quality indicators can be three main ones: implementation of new methods to assess the quality of life; choice of the most appropriate technique for a particular study among available methods; realization of the cognitive model and numerical experiment, which allows seeing the effect of external factors on the individual indicators of the quality of life. Thus, due to the high relevance and significant benefits from the use of the proposed method, the article is of interest to researchers of the quality of life

  2. Multinucleon Ejection Model for Two Body Current Neutrino Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Sobczyk, Jan T.; /Fermilab

    2012-06-01

    A model is proposed to describe nucleons ejected from a nucleus as a result of two-body-current neutrino interactions. The model can be easily implemented in Monte Carlo neutrino event generators. Various possibilities to measure the two-body-current contribution are discussed. The model can help identify genuine charge current quasielastic events and allow for a better determination of the systematic error on neutrino energy reconstruction in neutrino oscillation experiments.

  3. Rasch modeling of accuracy and confidence measures from cognitive tests.

    Science.gov (United States)

    Paek, Insu; Lee, Jihyun; Stankov, Lazar; Wilson, Mark

    2013-01-01

    The use of IRT models has not been rigorously applied in studies of the relationship between test-takers' confidence and accuracy. This study applied the Rasch measurement models to investigate the relationship between test-takers' confidence and accuracy on English proficiency tests, proposing potentially useful measures of under or overconfidence. The Rasch approach provided the scaffolding to formulate indices that can assess the discrepancy between confidence and accuracy at the item or total test level, as well as at particular ability levels locally. In addition, a "disattenuated" measure of association between accuracy and confidence, which takes measurement error into account, was obtained through a multidimensional Rasch modeling of the two constructs where the latent variance-covariance structure is directly estimated from the data. The results indicate that the participants tend to show overconfidence bias in their own cognitive abilities.

  4. Cooperative cognitive radio networking system model, enabling techniques, and performance

    CERN Document Server

    Cao, Bin; Mark, Jon W

    2016-01-01

    This SpringerBrief examines the active cooperation between users of Cooperative Cognitive Radio Networking (CCRN), exploring the system model, enabling techniques, and performance. The brief provides a systematic study on active cooperation between primary users and secondary users, i.e., (CCRN), followed by the discussions on research issues and challenges in designing spectrum-energy efficient CCRN. As an effort to shed light on the design of spectrum-energy efficient CCRN, they model the CCRN based on orthogonal modulation and orthogonally dual-polarized antenna (ODPA). The resource allocation issues are detailed with respect to both models, in terms of problem formulation, solution approach, and numerical results. Finally, the optimal communication strategies for both primary and secondary users to achieve spectrum-energy efficient CCRN are analyzed.

  5. Acceptance and Commitment Therapy versus Traditional Cognitive Behavioral Therapy: A Systematic Review and Meta-analysis of Current Empirical Evidence

    OpenAIRE

    2012-01-01

    Controversy remains about the empirical status of acceptance and commitment therapy (ACT) and its presumably different characteristics relative to traditional cognitive behavioral therapy (CBT). The current study aims to shed some light in this respect by conducting a systematic review and meta-analysis of the studies that have empirically compared ACT versus CBT. Sixteen studies comparing differential outcomes (N= 954) of ACT versus CBT in diverse problems were identified following several s...

  6. Current Status of Clinical and Experimental Researches on Cognitive Impairment in Diabetes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This article reviews the clinical and experimental researches on cognitive impairment related to diabetes in the recent decade. Most clinical studies indicate that the cognitive impairment in patients with type 1 diabetes mellitus is related to recurrent hypoglycemia closely. There is little research about whether or not hyperglycemia is related to cognitive impairment in patients with type 1 diabetes mellitus. Most studies indicate that the cognitive impairment in type 2 diabetes involves multiple factors through multiple mechanisms, including blood glucose, blood lipid, blood pressure, level of insulin, medication, chronic complication, etc. But, there has been no large-scale, multi-center, randomized controlled clinical trial in China recently. And what is more, some problems exist in this field of research, such as the lack of golden criterion of cognitive function measurement, different population of studied objects, and incomprehensive handling of confounding factors. Experimental studies found that hippocampal long-term potentiation (LTP) was impaired,which were manifested by impairment of spatial memory and decreased expression of LTP, but its relation to hyperglycemia, the duration of diabetes, learning and memory has always been differently reported by different researches. Thus, there are a lot of unknown things to be explored and studied in order to clarify its mechanism. TCM has abundant clinical experience in treating cerebral disease with medicine that enforces the kidney and promotes wit. However, there has been no research on treating diabetic cognitive impairment,which requires work to be done actively and TCM to be put into full play, in order to improve the treatment of diabetes and enhance living quality of patients.

  7. Calculus for cognitive scientists partial differential equation models

    CERN Document Server

    Peterson, James K

    2016-01-01

    This book shows cognitive scientists in training how mathematics, computer science and science can be usefully and seamlessly intertwined. It is a follow-up to the first two volumes on mathematics for cognitive scientists, and includes the mathematics and computational tools needed to understand how to compute the terms in the Fourier series expansions that solve the cable equation. The latter is derived from first principles by going back to cellular biology and the relevant biophysics.  A detailed discussion of ion movement through cellular membranes, and an explanation of how the equations that govern such ion movement leading to the standard transient cable equation are included. There are also solutions for the cable model using separation of variables, as well an explanation of why Fourier series converge and a description of the implementation of MatLab tools to compute the solutions. Finally, the standard Hodgkin - Huxley model is developed for an excitable neuron and is solved using MatLab.

  8. A cognitive learning model of clinical nursing leadership.

    Science.gov (United States)

    Pepin, Jacinthe; Dubois, Sylvie; Girard, Francine; Tardif, Jacques; Ha, Laurence

    2011-04-01

    Cognitive modeling of competencies is important to facilitate learning and evaluation. Clinical nursing leadership is considered a competency, as it is a "complex know-act" that students and nurses develop for the quality of care of patients and their families. Previous research on clinical leadership describes the attributes and characteristics of leaders and leadership, but, to our knowledge, a cognitive learning model (CLM) has yet to be developed. The purpose of our research was to develop a CLM of the clinical nursing leadership competency, from the beginning of a nursing program to expertise. An interpretative phenomenological study design was used 1) to document the experience of learning and practicing clinical leadership, and 2) to identify critical-learning turning points. Data was gathered from interviews with 32 baccalaureate students and 21 nurses from two clinical settings. An inductive analysis of data was conducted to determine the learning stages experienced: awareness of clinical leadership in nursing; integration of clinical leadership in actions; active leadership with patient/family; active leadership with the team; and, embedded clinical leadership extended to organizational level and beyond. The resulting CLM could have significant impact on both basic and continuing nursing education. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Reversing cognitive-motor impairments in Parkinson's disease patients using a computational modelling approach to deep brain stimulation programming.

    Science.gov (United States)

    Frankemolle, Anneke M M; Wu, Jennifer; Noecker, Angela M; Voelcker-Rehage, Claudia; Ho, Jason C; Vitek, Jerrold L; McIntyre, Cameron C; Alberts, Jay L

    2010-03-01

    Deep brain stimulation in the subthalamic nucleus is an effective and safe surgical procedure that has been shown to reduce the motor dysfunction of patients with advanced Parkinson's disease. Bilateral subthalamic nucleus deep brain stimulation, however, has been associated with declines in cognitive and cognitive-motor functioning. It has been hypothesized that spread of current to nonmotor areas of the subthalamic nucleus may be responsible for declines in cognitive and cognitive-motor functioning. The aim of this study was to assess the cognitive-motor performance in advanced Parkinson's disease patients with subthalamic nucleus deep brain stimulation parameters determined clinically (Clinical) to settings derived from a patient-specific computational model (Model). Data were collected from 10 patients with advanced Parkinson's disease bilaterally implanted with subthalamic nucleus deep brain stimulation systems. These patients were assessed off medication and under three deep brain stimulation conditions: Off, Clinical or Model based stimulation. Clinical stimulation parameters had been determined based on clinical evaluations and were stable for at least 6 months prior to study participation. Model-based parameters were selected to minimize the spread of current to nonmotor portions of the subthalamic nucleus using Cicerone Deep Brain Stimulation software. For each stimulation condition, participants performed a working memory (n-back task) and motor task (force tracking) under single- and dual-task settings. During the dual-task, participants performed the n-back and force-tracking tasks simultaneously. Clinical and Model parameters were equally effective in improving the Unified Parkinson's disease Rating Scale III scores relative to Off deep brain stimulation scores. Single-task working memory declines, in the 2-back condition, were significantly less under Model compared with Clinical deep brain stimulation settings. Under dual-task conditions, force

  10. Bayesian Fundamentalism or Enlightenment? On the explanatory status and theoretical contributions of Bayesian models of cognition.

    Science.gov (United States)

    Jones, Matt; Love, Bradley C

    2011-08-01

    The prominence of Bayesian modeling of cognition has increased recently largely because of mathematical advances in specifying and deriving predictions from complex probabilistic models. Much of this research aims to demonstrate that cognitive behavior can be explained from rational principles alone, without recourse to psychological or neurological processes and representations. We note commonalities between this rational approach and other movements in psychology - namely, Behaviorism and evolutionary psychology - that set aside mechanistic explanations or make use of optimality assumptions. Through these comparisons, we identify a number of challenges that limit the rational program's potential contribution to psychological theory. Specifically, rational Bayesian models are significantly unconstrained, both because they are uninformed by a wide range of process-level data and because their assumptions about the environment are generally not grounded in empirical measurement. The psychological implications of most Bayesian models are also unclear. Bayesian inference itself is conceptually trivial, but strong assumptions are often embedded in the hypothesis sets and the approximation algorithms used to derive model predictions, without a clear delineation between psychological commitments and implementational details. Comparing multiple Bayesian models of the same task is rare, as is the realization that many Bayesian models recapitulate existing (mechanistic level) theories. Despite the expressive power of current Bayesian models, we argue they must be developed in conjunction with mechanistic considerations to offer substantive explanations of cognition. We lay out several means for such an integration, which take into account the representations on which Bayesian inference operates, as well as the algorithms and heuristics that carry it out. We argue this unification will better facilitate lasting contributions to psychological theory, avoiding the pitfalls

  11. Assessing Cognitive and Affective Empathy Through the Interpersonal Reactivity Index: An Argument Against a Two-Factor Model.

    Science.gov (United States)

    Chrysikou, Evangelia G; Thompson, W Jake

    2016-12-01

    One aspect of higher order social cognition is empathy, a psychological construct comprising a cognitive (recognizing emotions) and an affective (responding to emotions) component. The complex nature of empathy complicates the accurate measurement of these components. The most widely used measure of empathy is the Interpersonal Reactivity Index (IRI). However, the factor structure of the IRI as it is predominantly used in the psychological literature differs from Davis's original four-factor model in that it arbitrarily combines the subscales to form two factors: cognitive and affective empathy. This two-factor model of the IRI, although popular, has yet to be examined for psychometric support. In the current study, we examine, for the first time, the validity of this alternative model. A confirmatory factor analysis showed poor model fit for this two-factor structure. Additional analyses offered support for the original four-factor model, as well as a hierarchical model for the scale. In line with previous findings, females scored higher on the IRI than males. Our findings indicate that the IRI, as it is currently used in the literature, does not accurately measure cognitive and affective empathy and highlight the advantages of using the original four-factor structure of the scale for empathy assessments. © The Author(s) 2015.

  12. Current-voltage model of LED light sources

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2012-01-01

    Amplitude modulation is rarely used for dimming light-emitting diodes in polychromatic luminaires due to big color shifts caused by varying magnitude of LED driving current and nonlinear relationship between intensity of a diode and driving current. Current-voltage empirical model of light...

  13. Ascorbic acid, cognitive function, and Alzheimer’s disease: a current review and future direction

    OpenAIRE

    Bowman, Gene L.

    2012-01-01

    This narrative review appraises the human and animal studies implicating ascorbic acid (AA) in normal cognitive function and Alzheimer’s disease. A research framework for how nutrition affects brain aging is proposed with emphasis on AA intake, status, metabolism, and transport into brain tissue. A final synopsis highlights areas for future research regarding AA nourishment and healthy brain aging.

  14. Mindfulness-Based Cognitive Therapy: Evaluating Current Evidence and Informing Future Research

    Science.gov (United States)

    Coelho, Helen F.; Canter, Peter H.; Ernst, Edzard

    2007-01-01

    Mindfulness-based cognitive therapy (MBCT) is a recently developed class-based program designed to prevent relapse or recurrence of major depression (Z. V. Segal, J. M. G. Williams, & J. Teasdale, 2002). Although research in this area is in its infancy, MBCT is generally discussed as a promising therapy in terms of clinical effectiveness. The aim…

  15. Experimental pain processing in individuals with cognitive impairment : current state of the science

    NARCIS (Netherlands)

    Defrin, Ruth; Amanzio, Martina; de Tommaso, Marina; Dimova, Violeta; Filipovic, Sasa; Finn, David P; Gimenez-Llort, Lydia; Invitto, Sara; Jensen-Dahm, Christina; Lautenbacher, Stefan; Oosterman, Joukje M; Petrini, Laura; Pick, Chaim G; Pickering, Gisele; Vase, Lene; Kunz, Miriam

    2015-01-01

    Cognitive impairment (CI) can develop during the course of ageing and is a feature of many neurological and neurodegenerative diseases. Many individuals with CI have substantial, sustained, and complex health care needs, which frequently include pain. However, individuals with CI can have difficulty

  16. Dysfunctional cognitions and their emotional, behavioral, and functional correlates in adults with attention deficit hyperactivity disorder (ADHD): is the cognitive-behavioral model valid?

    Science.gov (United States)

    Torrente, Fernando; López, Pablo; Alvarez Prado, Dolores; Kichic, Rafael; Cetkovich-Bakmas, Marcelo; Lischinsky, Alicia; Manes, Facundo

    2014-07-01

    To investigate the presence of dysfunctional cognitions in adults with ADHD and to determine whether these cognitions are associated with emotional symptoms, maladaptive coping, and functional impairment, as predicted by the cognitive-behavioral model. A total of 35 adult participants with ADHD, 20 nonclinical controls, and 20 non-ADHD clinical controls were assessed with measures of ADHD symptoms, dysfunctional cognitions, depression and anxiety symptoms, coping strategies, and quality of life. ADHD group showed elevated scores of dysfunctional cognitions relative to nonclinical control group and comparable with clinical control group. Dysfunctional cognitions were strongly associated with emotional symptoms. ADHD group also showed elevated scores in maladaptive coping strategies of the escape-avoidance type. Life impairment was satisfactorily predicted in data analysis when ADHD symptoms, dysfunctional cognitions, and emotional symptoms were fitted into a regression model. Cognitive-behavioral therapy model appears to be a valid complementary model for understanding emotional and life impairment in adults with ADHD. © 2012 SAGE Publications.

  17. Modeling the current distribution in HTS tapes with transport current and applied magnetic field

    NARCIS (Netherlands)

    Yazawa, Takashi; Rabbers, Jan-Jaap; Shevchenko, Oleg A.; Haken, ten Bennie; Kate, ten Herman H.J.; Maeda, Hideaki

    1999-01-01

    A numerical model is developed for the current distribution in a high temperature superconducting (HTS) tape, (Bi,Pb)2Sr2 Ca2Cu3Ox-Ag, subjected to a combination of a transport current and an applied magnetic field. This analysis is based on a two-dimensional formulation of Maxwell's equations in te

  18. Cognitive Elements of Empowerment: An "Interpretive" Model of Intrinsic Task Motivation

    OpenAIRE

    Thomas, Kenneth W.; Velthouse, Betty A.

    1990-01-01

    This article presents a cognitive model of empowerment. Here, empowerment is defined as increased intrinsic task motivation, and our subsequent model identifies four cognitions (task assessments) as the basis for worker empowerment: sense of impact, competence, meaningfulness, and choice. Adopting an interpretive perspective, we have used the model also to describe cognitive processes through which workers reach these conclusions. Central to the processes we describe are ...

  19. Model-based cognitive neuroscience: a conceptual introduction

    NARCIS (Netherlands)

    Forstmann, B.U.; Wagenmakers, E.-J.; Forstmann, B.U.; Wagenmakers, E.-J.

    2015-01-01

    This tutorial chapter shows how the separate fields of mathematical psychology and cognitive neuroscience can interact to their mutual benefit. Historically, the field of mathematical psychology is mostly concerned with formal theories of behavior, whereas cognitive neuroscience is mostly concerned

  20. Model-based cognitive neuroscience: a conceptual introduction

    NARCIS (Netherlands)

    Forstmann, B.U.; Wagenmakers, E.-J.; Forstmann, B.U.; Wagenmakers, E.-J.

    2015-01-01

    This tutorial chapter shows how the separate fields of mathematical psychology and cognitive neuroscience can interact to their mutual benefit. Historically, the field of mathematical psychology is mostly concerned with formal theories of behavior, whereas cognitive neuroscience is mostly concerned

  1. Latent Variable Models, Cognitive Modelling, and Working Memory: a Meeting Point

    OpenAIRE

    Rodríguez-Villagra, Odir Antonio

    2015-01-01

    Latent variable models and formal cognitive models share some elements of their object of study, variousphilosophical aspects, and some parts of their methodology. Nevertheless, little communication exists between their theories and findings. In order to highlight similarities and differences, this study implemented and tested a formal model proposing that interference among representations is a mechanism limiting working memory capacity (i.e., the interference model of Oberauer & Kliegl, 200...

  2. Characterizing Cognitive Aging of Working Memory and Executive Function in Animal Models

    Directory of Open Access Journals (Sweden)

    Jennifer Lynn Bizon

    2012-09-01

    Full Text Available Executive functions supported by prefrontal cortical systems provide essential control and planning mechanisms to guide goal-directed behavior. As such, age-related alterations in executive functions can mediate profound and widespread deficits on a diverse array of neurocognitive processes. Many of the critical neuroanatomical and functional characteristics of prefrontal cortex are preserved in rodents, allowing for meaningful cross-species comparisons relevant to the study of cognitive aging. In particular, as rodents lend themselves to genetic, cellular and biochemical approaches, rodent models of executive function stand to significantly contribute to our understanding of the critical neurobiological mechanisms that mediate decline of executive processes across the lifespan. Moreover, rodent analogues of executive functions that decline in human aging represent an essential component of a targeted, rational approach for developing and testing effective treatment and prevention therapies for age-related cognitive decline. This paper reviews behavioral approaches used to study executive function in rodents, with a focus on those assays that share a foundation in the psychological and neuroanatomical constructs important for human aging. A particular emphasis is placed on behavioral approaches used to assess working memory and cognitive flexibility, which are sensitive to decline with age across species and for which strong rodent models currently exist. In addition, other approaches in rodent behavior that have potential for providing analogues to functions that reliably decline to human aging (e.g., information processing speed are discussed.

  3. Characterizing cognitive aging of working memory and executive function in animal models.

    Science.gov (United States)

    Bizon, Jennifer L; Foster, Thomas C; Alexander, Gene E; Glisky, Elizabeth L

    2012-01-01

    Executive functions supported by prefrontal cortical (PFC) systems provide essential control and planning mechanisms to guide goal-directed behavior. As such, age-related alterations in executive functions can mediate profound and widespread deficits on a diverse array of neurocognitive processes. Many of the critical neuroanatomical and functional characteristics of prefrontal cortex are preserved in rodents, allowing for meaningful cross species comparisons relevant to the study of cognitive aging. In particular, as rodents lend themselves to genetic, cellular and biochemical approaches, rodent models of executive function stand to significantly contribute to our understanding of the critical neurobiological mechanisms that mediate decline of executive processes across the lifespan. Moreover, rodent analogs of executive functions that decline in human aging represent an essential component of a targeted, rational approach for developing and testing effective treatment and prevention therapies for age-related cognitive decline. This paper reviews behavioral approaches used to study executive function in rodents, with a focus on those assays that share a foundation in the psychological and neuroanatomical constructs important for human aging. A particular emphasis is placed on behavioral approaches used to assess working memory and cognitive flexibility, which are sensitive to decline with age across species and for which strong rodent models currently exist. In addition, other approaches in rodent behavior that have potential for providing analogs to functions that reliably decline to human aging (e.g., information processing speed) are discussed.

  4. Cognitive aging and hearing acuity: modeling spoken language comprehension.

    Science.gov (United States)

    Wingfield, Arthur; Amichetti, Nicole M; Lash, Amanda

    2015-01-01

    The comprehension of spoken language has been characterized by a number of "local" theories that have focused on specific aspects of the task: models of word recognition, models of selective attention, accounts of thematic role assignment at the sentence level, and so forth. The ease of language understanding (ELU) model (Rönnberg et al., 2013) stands as one of the few attempts to offer a fully encompassing framework for language understanding. In this paper we discuss interactions between perceptual, linguistic, and cognitive factors in spoken language understanding. Central to our presentation is an examination of aspects of the ELU model that apply especially to spoken language comprehension in adult aging, where speed of processing, working memory capacity, and hearing acuity are often compromised. We discuss, in relation to the ELU model, conceptions of working memory and its capacity limitations, the use of linguistic context to aid in speech recognition and the importance of inhibitory control, and language comprehension at the sentence level. Throughout this paper we offer a constructive look at the ELU model; where it is strong and where there are gaps to be filled.

  5. Modeling cognitive loads for evolving shared mental models in human-agent collaboration.

    Science.gov (United States)

    Fan, Xiaocong; Yen, John

    2011-04-01

    Recent research on human-centered teamwork highly demands the design of cognitive agents that can model and exploit human partners' cognitive load to enhance team performance. In this paper, we focus on teams composed of human-agent pairs and develop a system called Shared Mental Models for all--SMMall. SMMall implements a hidden Markov model (HMM)-based cognitive load model for an agent to predict its human partner's instantaneous cognitive load status. It also implements a user interface (UI) concept called shared belief map, which offers a synergic representation of team members' information space and allows them to share beliefs. An experiment was conducted to evaluate the HMM-based load models. The results indicate that the HMM-based load models are effective in helping team members develop a shared mental model (SMM), and the benefit of load-based information sharing becomes more significant as communication capacity increases. It also suggests that multiparty communication plays an important role in forming/evolving team SMMs, and when a group of agents can be partitioned into subteams, splitting messages by their load status can be more effective for developing subteam SMMs.

  6. The effects of juvenile stress on anxiety, cognitive bias and decision making in adulthood: a rat model.

    Directory of Open Access Journals (Sweden)

    Nichola M Brydges

    Full Text Available Stress experienced in childhood is associated with an increased risk of developing psychiatric disorders in adulthood. These disorders are particularly characterized by disturbances to emotional and cognitive processes, which are not currently fully modeled in animals. Assays of cognitive bias have recently been used with animals to give an indication of their emotional/cognitive state. We used a cognitive bias test, alongside a traditional measure of anxiety (elevated plus maze, to investigate the effects of juvenile stress (JS on adulthood behaviour using a rodent model. During the cognitive bias test, animals were trained to discriminate between two reward bowls based on a stimulus (rough/smooth sandpaper encountered before they reached the bowls. One stimulus (e.g. rough was associated with a lower value reward than the other (e.g. smooth. Once rats were trained, their cognitive bias was explored through the presentation of an ambiguous stimulus (intermediate grade sandpaper: a rat was classed as optimistic if it chose the bowl ordinarily associated with the high value reward. JS animals were lighter than controls, exhibited increased anxiety-like behaviour in the elevated plus maze and were more optimistic in the cognitive bias test. This increased optimism may represent an optimal foraging strategy for these underweight animals. JS animals were also faster than controls to make a decision when presented with an ambiguous stimulus, suggesting altered decision making. These results demonstrate that stress in the juvenile phase can increase anxiety-like behaviour and alter cognitive bias and decision making in adulthood in a rat model.

  7. Cognitive Systems Modeling and Analysis of Command and Control Systems

    Science.gov (United States)

    Norlander, Arne

    2012-01-01

    Military operations, counter-terrorism operations and emergency response often oblige operators and commanders to operate within distributed organizations and systems for safe and effective mission accomplishment. Tactical commanders and operators frequently encounter violent threats and critical demands on cognitive capacity and reaction time. In the future they will make decisions in situations where operational and system characteristics are highly dynamic and non-linear, i.e. minor events, decisions or actions may have serious and irreversible consequences for the entire mission. Commanders and other decision makers must manage true real time properties at all levels; individual operators, stand-alone technical systems, higher-order integrated human-machine systems and joint operations forces alike. Coping with these conditions in performance assessment, system development and operational testing is a challenge for both practitioners and researchers. This paper reports on research from which the results led to a breakthrough: An integrated approach to information-centered systems analysis to support future command and control systems research development. This approach integrates several areas of research into a coherent framework, Action Control Theory (ACT). It comprises measurement techniques and methodological advances that facilitate a more accurate and deeper understanding of the operational environment, its agents, actors and effectors, generating new and updated models. This in turn generates theoretical advances. Some good examples of successful approaches are found in the research areas of cognitive systems engineering, systems theory, and psychophysiology, and in the fields of dynamic, distributed decision making and naturalistic decision making.

  8. Cognitive bias in the chick anxiety-depression model.

    Science.gov (United States)

    Salmeto, Amy L; Hymel, Kristen A; Carpenter, Erika C; Brilot, Ben O; Bateson, Melissa; Sufka, Kenneth J

    2011-02-10

    Cognitive bias is a phenomenon that presents in clinical populations where anxious individuals tend to adopt a more pessimistic-like interpretation of ambiguous aversive stimuli whereas depressed individuals tend to adopt a less optimistic-like interpretation of ambiguous appetitive stimuli. To further validate the chick anxiety-depression model as a neuropsychiatric simulation we sought to quantify this cognitive endophenotype. Chicks exposed to an isolation stressor of 5m to induce an anxiety-like or 60 m to induce a depressive-like state were then tested in a straight alley maze to a series of morphed ambiguous appetitive (chick silhouette) to aversive (owl silhouette) cues. In non-isolated controls, runway start and goal latencies generally increased as a function of greater amounts of aversive characteristics in the cues. In chicks in the anxiety-like state, runway latencies were increased to aversive ambiguous cues, reflecting more pessimistic-like behavior. In chicks in the depression-like state, runway latencies were increased to both aversive and appetitive ambiguous cues, reflecting more pessimistic-like and less optimistic-like behavior, respectively.

  9. Predictive validity of a MK-801-induced cognitive impairment model in mice: implications on the potential limitations and challenges of modeling cognitive impairment associated with schizophrenia preclinically.

    Science.gov (United States)

    Brown, Jordan W; Rueter, Lynne E; Zhang, Min

    2014-03-03

    Cognitive impairment associated with schizophrenia (CIAS) is a major and disabling symptom domain of the disease that is generally unresponsive to current pharmacotherapies. Critically important to the discovery of novel therapeutics for CIAS is the utilization of preclinical models with robust predictive validity. We investigated the predictive validity of MK-801-induced memory impairments in mouse inhibitory avoidance (MK-IA) as a preclinical model for CIAS by investigating compounds that have been tested in humans, including antipsychotics, sodium channel blocker mood stabilizers, and putative cognitive enhancers. The atypical antipsychotic clozapine, as well as risperidone and olanzapine (see Brown et al., 2013), had no effect on MK-801-induced memory impairments. For sodium channel blockers, carbamazepine significantly attenuated memory impairments induced by MK-801, whereas lamotrigine had no effect. Nicotine, donepezil, modafinil, and xanomeline all significantly attenuated MK-801-induced memory impairments, but the magnitude of effects and the dose-responses observed varied across compounds. Clinically, only acute administration of nicotine has demonstrated consistent positive effects on CIAS, while inconsistent results have been reported for lamotrigine, donepezil, and modafinil; atypical antipsychotics produce only moderate improvements at best. A positive clinical signal has been observed with xanomeline, but only in a small pilot trial. The results presented here suggest that the MK-IA model lacks robust predictive validity for CIAS as the model is likely permissive and may indicate false positive signals for compounds and mechanisms that lack clear clinical efficacy for CIAS. Our findings also highlight the potential limitations and challenges of using NMDA receptor antagonists in rodents to model CIAS.

  10. Cognitive Model Exploration and Optimization: A New Challenge for Computational Science

    Science.gov (United States)

    2010-03-01

    colleagues is called MindModeling@Home, and it too runs on the BOINC infrastructure (Harris, Gluck, Mielke & Moore, 2009). Projects that work well with...mathematical and cognitive modeling. Cognitive Science, 33(5), 880-910. Harris, J., Gluck, K. A., Mielke , T., & Moore, L. R. (2009). MindModeling

  11. Parental Attachment, Cognitive Working Models, and Depression among African American College Students

    Science.gov (United States)

    Love, Keisha M.; Murdock, Tamera B.

    2012-01-01

    In an attempt to understand the cognitive mechanisms by which parental attachments predict depression among African American college students, the authors examined a mediational path model containing parental attachment, cognitive working models, and depression. The model demonstrated a close fit to the data, and several significant paths emerged.…

  12. Distributed Cognition and the Shared Knowledge Model of the Mazahua: A Cultural Approach.

    Science.gov (United States)

    de Haan, Mariette

    2002-01-01

    Discussion of distributed cognition and school reform focuses on the teaching and learning practices of a Native American group, the Mexican Mazahuas. Topics include knowledge construction; a shared knowledge model of learning; interconnectedness between knowledge and practice; models of guidance; cognitive apprenticeship models; shared…

  13. Ability, Breadth, and Parsimony in Computational Models of Higher-Order Cognition

    Science.gov (United States)

    Cassimatis, Nicholas L.; Bello, Paul; Langley, Pat

    2008-01-01

    Computational models will play an important role in our understanding of human higher-order cognition. How can a model's contribution to this goal be evaluated? This article argues that three important aspects of a model of higher-order cognition to evaluate are (a) its ability to reason, solve problems, converse, and learn as well as people do;…

  14. Implications of Neuroscientific Evidence for the Cognitive Models of Post-Traumatic Stress Disorder

    Science.gov (United States)

    Cruwys, Tegan; O'Kearney, Richard

    2008-01-01

    Brewin's dual representation theory, Ehlers and Clark's cognitive appraisal model, and Dalgleish's schematic, propositional, analogue and associative representational systems model are considered in the light of recent evidence on the neural substrates of post-traumatic stress disorder (PTSD). The models' proposals about the cognitive mechanism of…

  15. COGNITIVE MODELS OF PREDICTION THE DEVELOPMENT OF A DIVERSIFIED CORPORATION

    Directory of Open Access Journals (Sweden)

    Baranovskaya T. P.

    2016-10-01

    Full Text Available The application of classical forecasting methods applied to a diversified corporation faces some certain difficulties, due to its economic nature. Unlike other businesses, diversified corporations are characterized by multidimensional arrays of data with a high degree of distortion and fragmentation of information due to the cumulative effect of the incompleteness and distortion of accounting information from the enterprises in it. Under these conditions, the applied methods and tools must have high resolution and work effectively with large databases with incomplete information, ensure the correct common comparable quantitative processing of the heterogeneous nature of the factors measured in different units. It is therefore necessary to select or develop some methods that can work with complex poorly formalized tasks. This fact substantiates the relevance of the problem of developing models, methods and tools for solving the problem of forecasting the development of diversified corporations. This is the subject of this work, which makes it relevant. The work aims to: 1 analyze the forecasting methods to justify the choice of system-cognitive analysis as one of the effective methods for the prediction of semi-structured tasks; 2 to adapt and develop the method of systemic-cognitive analysis for forecasting of dynamics of development of the corporation subject to the scenario approach; 3 to develop predictive model scenarios of changes in basic economic indicators of development of the corporation and to assess their credibility; 4 determine the analytical form of the dependence between past and future scenarios of various economic indicators; 5 develop analytical models weighing predictable scenarios, taking into account all prediction results with positive levels of similarity, to increase the level of reliability of forecasts; 6 to develop a calculation procedure to assess the strength of influence on the corporation (sensitivity of its

  16. Cognitive science, psychoanalysis and neuroscience: A Brief History of a current trend (Part I

    Directory of Open Access Journals (Sweden)

    Antonio Imbasciati

    2015-05-01

    Full Text Available For decades, cognitive sciences and psychoanalysis have been ignored each other for a mutual distrust, producing in scholars of both disciplines a progressive mutual ignorance and misunderstanding about their developments. The latest studies of cognitive sciences on the role of emotions have allowed a partial approach to psychoanalysis. But above all, recent studies in neuroscience on the emotional basis of all mental processes, about the formation of the subjectivity, about identity and sense of self (neuro psychoanalysis, are opening up a horizon of integration between the three different sciences. In this perspective the epigenetics is playing a fundamental role, that the Author hopes will produce significant developments from a social and anthropological point of view. 

  17. Cognitive science, psychoanalysis and neuroscience: A Brief History of a current trend (Part II

    Directory of Open Access Journals (Sweden)

    Antonio Imbasciati

    2015-10-01

    Full Text Available For decades, cognitive sciences and psychoanalysis have been ignored each other for a mutual distrust, producing in scholars of both disciplines a progressive mutual ignorance and misunderstanding about their developments. The latest studies of cognitive sciences on the role of emotions have allowed a partial approach to psychoanalysis. But above all, recent studies in neuroscience on the emotional basis of all mental processes, about the formation of the subjectivity, about identity and sense of self (neuro psychoanalysis, are opening up a horizon of integration between the three different sciences. In this perspective the epigenetics is playing a fundamental role, that the Author hopes will produce significant developments from a social and anthropological point of view. 

  18. Neurocognitive and Social Cognitive Approaches for Improving Functional Outcome in Early Psychosis: Theoretical Considerations and Current State of Evidence

    Directory of Open Access Journals (Sweden)

    Cali F. Bartholomeusz

    2012-01-01

    Full Text Available Improving functional outcome, in addition to alleviating psychotic symptoms, is now a major treatment objective in schizophrenia research. Given the large body of evidence suggesting pharmacological treatments generally have minimal effects on indices of functioning, research has turned to psychosocial rehabilitation programs. Among these, neurocognitive and social cognitive interventions are at the forefront of this field and are argued to target core deficits inherent to the schizophrenia illness. However, to date, research trials have primarily focused on chronic schizophrenia populations, neglecting the early psychosis groups who are often as severely impaired in social and occupational functioning. This theoretical paper will outline the rationale for investigating adjunctive cognitive-based interventions in the early phases of psychotic illness, critically examine the current approach strategies used in these interventions, and assess the evidence supporting certain training programs for improving functional outcome in early psychosis. Potential pathways for future research will be discussed.

  19. The effect of parental modeling of anxious behaviors and cognitions in school-aged children: an experimental pilot study.

    Science.gov (United States)

    Burstein, Marcy; Ginsburg, Golda S

    2010-06-01

    The current study tested: (1) the impact of parental modeling of anxious behaviors and cognitions on child anxiety level, anxious cognitions, desired avoidance, and objective performance using an experimental paradigm; and (2) whether the impact of parental modeling of anxious behaviors and cognitions differed by parent gender. Twenty-five parents (a random selection of 12 male and 13 female parents) participated with one of their children (ages 8-12 years; 56.0% male; 76.0% Caucasian). All children experienced two test conditions: an anxious condition in which their parent was trained to act anxiously before a planned spelling test and a non-anxious condition in which their parent was trained to act in a relaxed and confident manner before a planned spelling test. Results showed that, regardless of parent gender, children endorsed higher anxiety levels, anxious cognitions, and desired avoidance of the spelling test in the anxious relative to the non-anxious condition. Parental modeling of anxiety did not affect child spelling performance. Significant interaction effects indicated that fathers had a stronger impact on child anxiety level and cognitions than did mothers. Results highlight the importance of parental modeling and the potential role of both mothers and fathers in prevention and treatment for child anxiety. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  20. Relationship between cognitive functioning impairment and nutrition in obesity: Current Perspective

    OpenAIRE

    Macit, Sedanur; Gezmen Karadağ, Makbule

    2015-01-01

    Obesity is one of the serious public health problems and its prevalence has been increasing in recent years. As well as causing health problems, obesity is associated with cognitive function impairment, especially with reduced language, motor capacity skills, and attention named as executive functions. Obesity is also related to decrease in brain volume, dementia, Alzheimer’s disease, sociopathic, aggressive personality traits, anxiety, and major depressive disorder. There are several mechani...

  1. The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence From Word Segmentation.

    Science.gov (United States)

    Phillips, Lawrence; Pearl, Lisa

    2015-11-01

    The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's cognitive plausibility. We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition model can aim to be cognitively plausible in multiple ways. We discuss these cognitive plausibility checkpoints generally and then apply them to a case study in word segmentation, investigating a promising Bayesian segmentation strategy. We incorporate cognitive plausibility by using an age-appropriate unit of perceptual representation, evaluating the model output in terms of its utility, and incorporating cognitive constraints into the inference process. Our more cognitively plausible model shows a beneficial effect of cognitive constraints on segmentation performance. One interpretation of this effect is as a synergy between the naive theories of language structure that infants may have and the cognitive constraints that limit the fidelity of their inference processes, where less accurate inference approximations are better when the underlying assumptions about how words are generated are less accurate. More generally, these results highlight the utility of incorporating cognitive plausibility more fully into computational models of language acquisition.

  2. Transcranial direct current stimulation facilitates cognitive multi-task performance differentially depending on anode location and subtask.

    Directory of Open Access Journals (Sweden)

    Melissa eScheldrup

    2014-09-01

    Full Text Available There is a need to facilitate acquisition of real world cognitive multi-tasks that require long periods of training (e.g., air traffic control, intelligence analysis, medicine. Non-invasive brain stimulation – specifically transcranial Direct Current Stimulation (tDCS – has promise as a method to speed multi-task training. We hypothesized that during acquisition of the complex multi-task Space Fortress, subtasks that require focused attention on ship control would benefit from tDCS aimed at the dorsal attention network while subtasks that require redirection of attention would benefit from tDCS aimed at the right hemisphere ventral attention network. We compared effects of 30 min prefrontal and parietal stimulation to right and left hemispheres on subtask performance during the first 45 min of training. The strongest effects both overall and for ship flying (control and velocity subtasks were seen with a right parietal (C4 to left shoulder montage, shown by modeling to induce an electric field that includes nodes in both dorsal and ventral attention networks. This is consistent with the re-orienting hypothesis that the ventral attention network is activated along with the dorsal attention network if a new, task-relevant event occurs while visuospatial attention is focused (Corbetta et al., 2008. No effects were seen with anodes over sites that stimulated only dorsal (C3 or only ventral (F10 attention networks. The speed subtask (update memory for symbols benefited from an F9 anode over left prefrontal cortex. These results argue for development of tDCS as a training aid in real world settings where multi-tasking is critical.

  3. The Motor-Cognitive Model of Motor Imagery: Evidence From Timing Errors in Simulated Reaching and Grasping.

    Science.gov (United States)

    Glover, Scott; Baran, Marek

    2017-04-03

    Motor imagery represents an important but theoretically underdeveloped area of research in psychology. The motor-cognitive model of motor imagery was presented, and contrasted with the currently prevalent view, the functional equivalence model. In 3 experiments, the predictions of the two models were pitted against each other through manipulations of task precision and the introduction of an interference task, while comparing their effects on overt actions and motor imagery. In Experiments 1a and 1b, the motor-cognitive model predicted an effect of precision whereby motor imagery would overestimate simulated movement times when a grasping action involved a high level of precision; this prediction was upheld. In Experiment 2, the motor-cognitive model predicted that an interference task would slow motor imagery to a much greater extent than it would overt actions; this prediction was also upheld. Experiment 3 showed that the effects observed in the previous experiments could not be due to failures to match the motor imagery and overt action tasks. None of the above results were explainable by either a strong version of the functional equivalence model, or any reasonable adaptations thereof. It was concluded that the motor-cognitive model may represent a theoretically viable advance in the understanding of motor imagery. (PsycINFO Database Record

  4. Cognitive modeling and multi criteria decision making in macroeconomic analysis

    Directory of Open Access Journals (Sweden)

    Leonova Nina

    2014-01-01

    Full Text Available Decision making in macroeconomics belongs to the class of ill-structured tasks with strong external factors interdependence, a limited number of management tools and experts groups' subjectivity. This paper suggests a technique of macroeconomic analysis which includes methods of cognitive modeling for formalizing a problem situation and scenario generation as a basis of the typical multicriteria decision making task. In turn, for solving this task is suggested a method based on measuring the distance to the 'ideal' solution with determining importance of criteria by finding objective, common component of all values measured by experts groups. For extracting this 'commonality' means of factor analysis are used. Such an approach allows separating of the objective part in experts' value from a subjective one, while the technique at whole provides formalization of macroeconomic problems and substantiation of decision-making in macroeconomics.

  5. Current focusing and steering: modeling, physiology, and psychophysics.

    Science.gov (United States)

    Bonham, Ben H; Litvak, Leonid M

    2008-08-01

    Current steering and current focusing are stimulation techniques designed to increase the number of distinct perceptual channels available to cochlear implant (CI) users by adjusting currents applied simultaneously to multiple CI electrodes. Previous studies exploring current steering and current focusing stimulation strategies are reviewed, including results of research using computational models, animal neurophysiology, and human psychophysics. Preliminary results of additional neurophysiological and human psychophysical studies are presented that demonstrate the success of current steering strategies in stimulating auditory nerve regions lying between physical CI electrodes, as well as current focusing strategies that excite regions narrower than those stimulated using monopolar configurations. These results are interpreted in the context of perception and speech reception by CI users. Disparities between results of physiological and psychophysical studies are discussed. The differences in stimulation used for physiological and psychophysical studies are hypothesized to contribute to these disparities. Finally, application of current steering and focusing strategies to other types of auditory prostheses is also discussed.

  6. Current filamentation model for the Weibel/Filamentation instabilities

    Science.gov (United States)

    Ryu, Chang-Mo; Huynh, Cong Tuan; Kim, Chul Min

    2016-10-01

    A current filamentaion model for a nonrelativistic plasma with e +/e- beam has been presented together with PIC simulations, which can explain the mangetic field enhancement during the Weibel/ Filamentation instabilities. This filament model assumes the Hammer-Rostoker equilibrium. In addition, this model predicts preferential acceleration/deceleration for electron-ion plasmas depending on the injected beam to be e +/e-.

  7. Explorations in combining cognitive models of individuals and system dynamics models of groups.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.

    2008-07-01

    This report documents a demonstration model of interacting insurgent leadership, military leadership, government leadership, and societal dynamics under a variety of interventions. The primary focus of the work is the portrayal of a token societal model that responds to leadership activities. The model also includes a linkage between leadership and society that implicitly represents the leadership subordinates as they directly interact with the population. The societal model is meant to demonstrate the efficacy and viability of using System Dynamics (SD) methods to simulate populations and that these can then connect to cognitive models depicting individuals. SD models typically focus on average behavior and thus have limited applicability to describe small groups or individuals. On the other hand, cognitive models readily describe individual behavior but can become cumbersome when used to describe populations. Realistic security situations are invariably a mix of individual and population dynamics. Therefore, the ability to tie SD models to cognitive models provides a critical capability that would be otherwise be unavailable.

  8. Pharmacological reversal of cognitive bias in the chick anxiety-depression model.

    Science.gov (United States)

    Hymel, Kristen A; Sufka, Kenneth J

    2012-01-01

    Cognitive bias presents in clinical populations where anxious individuals adopt a more pessimistic interpretation of ambiguous aversive stimuli and depressed individuals adopt both a more pessimistic interpretation of ambiguous aversive stimuli and a less optimistic interpretation of ambiguous appetitive stimuli. These biases have been reversed by anxiolytics and antidepressants. In the current study, chicks exposed to an isolation stressor of 5-min to induce an anxiety-like state or 60-min to induce a depressive-like state were tested in a straight alley maze to a series of morphed ambiguous appetitive (chick silhouette) to aversive (owl silhouette) cues. Chicks in the depression-like state displayed more pessimistic-like and less optimistic-like approach behavior to ambiguous aversive and appetitive cues, respectively. Both forms of cognitive bias were reversed by 15.0 mg/kg imipramine. Chicks in anxiety-like state displayed more pessimistic-like approach behavior under the ambiguous aversive stimulus cues. However, 0.10 mg/kg clonidine produced modest sedation and thus, was ineffective at reversing this bias. The observation that cognitive biases of more pessimism and less optimism can be reversed in the depression-like phase by imipramine adds to the validity of the chick anxiety-depression model as a neuropsychiatric simulation. This article is part of a Special Issue entitled 'Anxiety and Depression'.

  9. Computational models of music perception and cognition II: Domain-specific music processing

    Science.gov (United States)

    Purwins, Hendrik; Grachten, Maarten; Herrera, Perfecto; Hazan, Amaury; Marxer, Ricard; Serra, Xavier

    2008-09-01

    In Part I [Purwins H, Herrera P, Grachten M, Hazan A, Marxer R, Serra X. Computational models of music perception and cognition I: The perceptual and cognitive processing chain. Physics of Life Reviews 2008, in press, doi:10.1016/j.plrev.2008.03.004], we addressed the study of cognitive processes that underlie auditory perception of music, and their neural correlates. The aim of the present paper is to summarize empirical findings from music cognition research that are relevant to three prominent music theoretic domains: rhythm, melody, and tonality. Attention is paid to how cognitive processes like category formation, stimulus grouping, and expectation can account for the music theoretic key concepts in these domains, such as beat, meter, voice, consonance. We give an overview of computational models that have been proposed in the literature for a variety of music processing tasks related to rhythm, melody, and tonality. Although the present state-of-the-art in computational modeling of music cognition definitely provides valuable resources for testing specific hypotheses and theories, we observe the need for models that integrate the various aspects of music perception and cognition into a single framework. Such models should be able to account for aspects that until now have only rarely been addressed in computational models of music cognition, like the active nature of perception and the development of cognitive capacities from infancy to adulthood.

  10. Social Cognitive Model of College Satisfaction: A Test of Measurement and Path Models

    Science.gov (United States)

    Feldt, Ronald C.

    2012-01-01

    The study examined a model that integrates social-cognitive and trait-personality constructs to examine two domains of college satisfaction. Direct and indirect effects were observed for conscientiousness, perception of institutional resources, self-efficacy, and goal progress. Paths differed for personal and institutional satisfaction. Most…

  11. Quantum current operators; 3, Commutative quantum current operators semi-infinite construction and functional models

    CERN Document Server

    Ding, J; Ding, Jintai; Feigin, Boris

    1996-01-01

    We construct a commutative current operator $\\bar x^+(z)$ inside $U_q(\\hat{\\frak sl}(2))$. With this operator and the condition of quantum integrability on the quantum current of $U_q(\\hat{\\frak sl}(2))$, we derive the quantization of the semi-infinite construction of integrable modules of The quantization of the functional models for $\\hat{\\frak sl}(2)$ are also given.

  12. A continuum model for current distribution in Rutherford cables

    CERN Document Server

    Akhmedov, A I; Breschi, M

    2001-01-01

    An analysis of eddy currents induced in flat Rutherford-type cables by external time dependent magnetic fields has been performed. The induced currents generate in turn a secondary magnetic field which has a longitudinal periodicity (periodic pattern). The dependence of the amplitude of the pattern on the history of the cable excitation has been investigated. The study has been carried out with two different models for the simulation of current distribution in Rutherford cables, namely a network model, based on a lumped parameters circuit and a "continuum" model, based on a distributed parameters circuit. We show the results of simulations of the current distribution in the inner cable of a short LHC dipole model in different powering conditions and compare them to experimental data. (12 refs).

  13. Cardiac magnetic source imaging based on current multipole model

    Institute of Scientific and Technical Information of China (English)

    Tang Fa-Kuan; Wang Qian; Hua Ning; Lu Hong; Tang Xue-Zheng; Ma Ping

    2011-01-01

    It is widely accepted that the heart current source can be reduced into a current multipole. By adopting three linear inverse methods, the cardiac magnetic imaging is achieved in this article based on the current multipole model expanded to the first order terms. This magnetic imaging is realized in a reconstruction plane in the centre of human heart, where the current dipole array is employed to represent realistic cardiac current distribution. The current multipole as testing source generates magnetic fields in the measuring plane, serving as inputs of cardiac magnetic inverse problem. In the heart-torso model constructed by boundary element method, the current multipole magnetic field distribution is compared with that in the homogeneous infinite space, and also with the single current dipole magnetic field distribution.Then the minimum-norm least-squares (MNLS) method, the optimal weighted pseuDOInverse method (OWPIM), and the optimal constrained linear inverse method (OCLIM) are selected as the algorithms for inverse computation based on current multipole model innovatively, and the imaging effects of these three inverse methods are compared. Besides,two reconstructing parameters, residual and mean residual, are also discussed, and their trends under MNLS, OWPIM and OCLIM each as a function of SNR are obtained and compared.

  14. Processes models, environmental analyses, and cognitive architectures: quo vadis quantum probability theory?

    Science.gov (United States)

    Marewski, Julian N; Hoffrage, Ulrich

    2013-06-01

    A lot of research in cognition and decision making suffers from a lack of formalism. The quantum probability program could help to improve this situation, but we wonder whether it would provide even more added value if its presumed focus on outcome models were complemented by process models that are, ideally, informed by ecological analyses and integrated into cognitive architectures.

  15. A Prospective Test of Cognitive Vulnerability Models of Depression with Adolescent Girls

    Science.gov (United States)

    Bohon, Cara; Stice, Eric; Burton, Emily; Fudell, Molly; Nolen-Hoeksema, Susan

    2008-01-01

    This study sought to provide a more rigorous prospective test of two cognitive vulnerability models of depression with longitudinal data from 496 adolescent girls. Results supported the cognitive vulnerability model in that stressors predicted future increases in depressive symptoms and onset of clinically significant major depression for…

  16. A Note on Comparing Examinee Classification Methods for Cognitive Diagnosis Models

    Science.gov (United States)

    Huebner, Alan; Wang, Chun

    2011-01-01

    Cognitive diagnosis models have received much attention in the recent psychometric literature because of their potential to provide examinees with information regarding multiple fine-grained discretely defined skills, or attributes. This article discusses the issue of methods of examinee classification for cognitive diagnosis models, which are…

  17. Cognitive Modeling and Self-Efficacy: Effects on Preservice Teachers' Learning of Teaching Strategies.

    Science.gov (United States)

    Gorrell, Jeffrey; Capron, Earl

    1990-01-01

    Examines how cognitive modeling and self-efficacy affected preservice teachers' learning of teaching strategies. Two groups of students viewed videotaped training sessions with direct instruction or cognitive modeling. They then viewed either self-efficacy or task-oriented commentaries. Results indicated significant effects favoring cognitive…

  18. A Model for Developing Meta-Cognitive Tools in Teacher Apprenticeships

    Science.gov (United States)

    Bray, Paige; Schatz, Steven

    2013-01-01

    This research investigates a model for developing meta-cognitive tools to be used by pre-service teachers during apprenticeship (student teaching) experience to operationalise the epistemological model of Cook and Brown (2009). Meta-cognitive tools have proven to be effective for increasing performance and retention of undergraduate students.…

  19. Test of a Social Cognitive Model of Work Satisfaction in Teachers

    Science.gov (United States)

    Duffy, Ryan D.; Lent, Robert W.

    2009-01-01

    Lent and Brown [Lent, R. W., & Brown, S. D. (2006). "Integrating person and situation perspectives on work satisfaction: A social-cognitive view." "Journal of Vocational Behavior,69", 236-247] recently proposed an integrative model of work satisfaction linked to social cognitive career theory. The model posits that work satisfaction is predicted…

  20. A Biblical-Theological Model of Cognitive Dissonance Theory: Relevance for Christian Educators

    Science.gov (United States)

    Bowen, Danny Ray

    2012-01-01

    The purpose of this content analysis research was to develop a biblical-theological model of Cognitive Dissonance Theory applicable to pedagogy. Evidence of cognitive dissonance found in Scripture was used to infer a purpose for the innate drive toward consonance. This inferred purpose was incorporated into a model that improves the descriptive…

  1. Flexible Design and Implementation of Cognitive Models for Predicting Pilot Errors in Cockpit Design

    NARCIS (Netherlands)

    Diggelen, J. van; Janssen, J.; Mioch, T.

    2010-01-01

    This paper describes an integrated design and implementation framework for cognitive models in complex task environments. We propose a task- and humancentered development methodology for deriving the cognitive models, and present a goal-based framework for implementing them. We illustrate our approa

  2. Cognitive Models of Writing: Writing Proficiency as a Complex Integrated Skill

    Science.gov (United States)

    Deane, Paul; Odendahl, Nora; Quinlan, Thomas; Fowles, Mary; Welsh, Cyndi; Bivens-Tatum, Jennifer

    2008-01-01

    This paper undertakes a review of the literature on writing cognition, writing instruction, and writing assessment with the goal of developing a framework and competency model for a new approach to writing assessment. The model developed is part of the Cognitively Based Assessments of, for, and as Learning (CBAL) initiative, an ongoing research…

  3. A Biblical-Theological Model of Cognitive Dissonance Theory: Relevance for Christian Educators

    Science.gov (United States)

    Bowen, Danny Ray

    2012-01-01

    The purpose of this content analysis research was to develop a biblical-theological model of Cognitive Dissonance Theory applicable to pedagogy. Evidence of cognitive dissonance found in Scripture was used to infer a purpose for the innate drive toward consonance. This inferred purpose was incorporated into a model that improves the descriptive…

  4. Modelling of the ring current in Saturn's magnetosphere

    Science.gov (United States)

    Giampieri, G.; Dougherty, M.

    2004-02-01

    . The existence of a ring current inside Saturn's magnetosphere was first suggested by smith80 and ness81,ness82, in order to explain various features in the magnetic field observations from the Pioneer 11 and Voyager 1 and 2 spacecraft. connerney83 formalized the equatorial current model, based on previous modelling work of Jupiter's current sheet and estimated its parameters from the two Voyager data sets. Here, we investigate the model further, by reconsidering the data from the two Voyager spacecraft, as well as including the Pioneer 11 flyby data set. First, we obtain, in closed form, an analytic expression for the magnetic field produced by the ring current. We then fit the model to the external field, that is the difference between the observed field and the internal magnetic field, considering all the available data. In general, through our global fit we obtain more accurate parameters, compared to previous models. We point out differences between the model's parameters for the three flybys, and also investigate possible deviations from the axial and planar symmetries assumed in the model. We conclude that an accurate modelling of the Saturnian disk current will require taking into account both of the temporal variations related to the condition of the magnetosphere, as well as non-axisymmetric contributions due to local time effects.

  5. Cognitive Modeling for Closed-Loop Task Mitigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As flightdeck equipment becomes more sophisticated and complex, operations become significantly more cognitively demanding. When tasks demands exceed the operator's...

  6. Focus group reflections on the current and future state of cognitive assessment tools in geriatric health care

    Directory of Open Access Journals (Sweden)

    Whitehead JC

    2015-06-01

    Full Text Available Jocelyne C Whitehead,1 Sara A Gambino,1 Jeffrey D Richter,2 Jennifer D Ryan1,3,41Rotman Research Institute, Baycrest, 2Independent Human Factors Consultant, Toronto, ON, Canada; 3Department of Psychology, 4Department of Psychiatry, University of Toronto, Toronto, ON, CanadaObjective: This study provides insight into the thoughts and opinions of geriatric health-care professionals toward cognitive assessments and the use of emerging technologies, such as eye-tracking, to supplement current tools.Methods: Two focus group sessions were conducted with nurses and physicians who routinely administer neurocognitive assessments to geriatric populations. Video recordings of the focus group sessions were transcribed and a thematic analysis was performed.Results: Participants reported the need for assessment and diagnostic tools that are accessible and efficient, and that are capable of accommodating the rapid growth in the aging population. The prevalence of more complex ailments experienced by older adults has had repercussions in the quality of care that the clients receive, and has contributed to lengthy wait times and resource shortages. Health-care professionals stated that they are hampered by the disjointed structure of the health-care system and that they would benefit from a more efficient allocation of responsibilities made possible through tools that did not require extensive training or certification. Eyetracking-based cognitive assessments were thought to strongly complement this system, yet it was thought that difficulty would be faced in gaining the support and increased uptake by health-care professionals due to the nonintuitive relationship between eyetracking and cognition.Conclusion: The findings suggest that health-care professionals are receptive to the use of eyetracking technology to assess for cognitive health as it would conserve resources by allowing frontline staff to administer assessments with minimal training

  7. Neurocognitive Poetics: methods and models for investigating the neuronal and cognitive- affective bases of literature reception

    Directory of Open Access Journals (Sweden)

    Arthur M Jacobs

    2015-04-01

    Full Text Available A long tradition of research including classical rhetoric, aesthetics and poetics theory, formalism and structuralism, as well as current perspectives in (neurocognitive poetics has investigated structural and functional aspects of literature reception. Despite a wealth of literature published in specialised journals like Poetics, however, still little is known about how the brain processes and creates literary and poetic texts. Still, such stimulus material might be suited better than other genres for demonstrating the complexities with which our brain constructs the world in and around us, because it unifies thought and language, music and imagery in a clear, manageable way, most often with play, pleasure, and emotion (Schrott & Jacobs, 2011. In this paper, I discuss methods and models for investigating the neuronal and cognitive-affective bases of literary reading together with pertinent results from studies on poetics, text processing, emotion, or neuroaesthetics, and outline current challenges and future perspectives.

  8. Significance of Cultural-Historical Theory of Psychological Development of L.S. Vygotsky for the Development of Modern Models of Social Cognition and Psychotherapy

    Directory of Open Access Journals (Sweden)

    Kholmogorova A.B.,

    2016-12-01

    Full Text Available The article acknowledges the situation of methodical crisis in modern research of social cognition related to the domination of reductive approaches that ignore the uniqueness of human psyche. Heuristicity of concepts of cultural-historical theory of psychological development of L.S. Vygotsky, which serves to overcome the apparent inconsistencies is substantiated. Models of social cognition based on the principles of cultural-historical psychology are described, those being the model of social cognition within phylogenesis of M. Tomasello, and the model of social cognition within ontogenesis of C. Fernyhough. Current situation in the area of mental health is reviewed from the standpoint of cultural-historical psychology, its specifics reflected in the increased burden on reflexive functions, that is, skills lying within the sphere of social cognition is substantiated. Modern psychotherapeutic apparatus directed to compensate social cognition deficits due to various psychiatric disorders is reviewed. The assumption that adolescense is sensitive period for the development of higher forms of social cognition is made, and a summary of researches supporting this assertion is presented. Main contradictions of modern-day maturing are enunciated. To conclude the presented theoretical analysis, a comprehensive multiple-factor model of social cognition is presented based on concepts of cultural-historical theory of L.S. Vygotsky.

  9. Some interrelationships between constructivist models of learning and current neurobiological theory, with implications for science education

    Science.gov (United States)

    Anderson, O. Roger

    Recent advances in the neurosciences have begun to elucidate how some fundamental mechanisms of nervous system activity can explain human information processing and the acquisition of knowledge. Some of these findings are consistent with a cognitive view of constructivist models of learning and provide additional theoretical support for constructivist applications to science education reform. Current thought at the interface between neurocognitive research and constructivist philosophy is summarized here and discussed in a context of implications for scientific epistemology and conceptual change processes in science education.

  10. The impact of motivation on cognitive performance in an animal model of the negative and cognitive symptoms of schizophrenia.

    Science.gov (United States)

    Ward, Ryan D; Winiger, Vanessa; Higa, Kerin K; Kahn, Julia B; Kandel, Eric R; Balsam, Peter D; Simpson, Eleanor H

    2015-06-01

    Interactions between motivation and cognition are implicated in producing functional impairments and poor quality of life in psychiatric patients. This interaction, however, is not well understood at either the behavioral or neural level. We developed a procedure for mice in which a cognitive measure, sustained attention, is modulated by a motivationally relevant signal that predicts reward probability on a trial-by-trial basis. Using this paradigm, we tested the interaction between motivation and cognition in mice that model the increased striatal D2 receptor activity observed in schizophrenia patients (D2R-OE mice). In control mice, attention was modulated by signaled-reward probability. In D2R-OE mice, however, attention was not modulated by reward-related cues. This impairment was not due to any global deficits in attention or maintenance of the trial-specific information in working memory. Turning off the transgene in D2R-OE mice rescued the motivational modulation of attention. These results indicate that deficits in motivation impair the ability to use reward-related cues to recruit attention and that improving motivation improves functional cognitive performance. These results further suggest that addressing motivational impairments in patients is critical to achieving substantive cognitive and functional gains.

  11. Inter-model analysis of tsunami-induced coastal currents

    Science.gov (United States)

    Lynett, Patrick J.; Gately, Kara; Wilson, Rick; Montoya, Luis; Arcas, Diego; Aytore, Betul; Bai, Yefei; Bricker, Jeremy D.; Castro, Manuel J.; Cheung, Kwok Fai; David, C. Gabriel; Dogan, Gozde Guney; Escalante, Cipriano; González-Vida, José Manuel; Grilli, Stephan T.; Heitmann, Troy W.; Horrillo, Juan; Kânoğlu, Utku; Kian, Rozita; Kirby, James T.; Li, Wenwen; Macías, Jorge; Nicolsky, Dmitry J.; Ortega, Sergio; Pampell-Manis, Alyssa; Park, Yong Sung; Roeber, Volker; Sharghivand, Naeimeh; Shelby, Michael; Shi, Fengyan; Tehranirad, Babak; Tolkova, Elena; Thio, Hong Kie; Velioğlu, Deniz; Yalçıner, Ahmet Cevdet; Yamazaki, Yoshiki; Zaytsev, Andrey; Zhang, Y. J.

    2017-06-01

    To help produce accurate and consistent maritime hazard products, the National Tsunami Hazard Mitigation Program organized a benchmarking workshop to evaluate the numerical modeling of tsunami currents. Thirteen teams of international researchers, using a set of tsunami models currently utilized for hazard mitigation studies, presented results for a series of benchmarking problems; these results are summarized in this paper. Comparisons focus on physical situations where the currents are shear and separation driven, and are thus de-coupled from the incident tsunami waveform. In general, we find that models of increasing physical complexity provide better accuracy, and that low-order three-dimensional models are superior to high-order two-dimensional models. Inside separation zones and in areas strongly affected by eddies, the magnitude of both model-data errors and inter-model differences can be the same as the magnitude of the mean flow. Thus, we make arguments for the need of an ensemble modeling approach for areas affected by large-scale turbulent eddies, where deterministic simulation may be misleading. As a result of the analyses presented herein, we expect that tsunami modelers now have a better awareness of their ability to accurately capture the physics of tsunami currents, and therefore a better understanding of how to use these simulation tools for hazard assessment and mitigation efforts.

  12. Stimulation of Dorsolateral Prefrontal Cortex Enhances Adaptive Cognitive Control: A High-Definition Transcranial Direct Current Stimulation Study.

    Science.gov (United States)

    Gbadeyan, Oyetunde; McMahon, Katie; Steinhauser, Marco; Meinzer, Marcus

    2016-12-14

    Conflict adaptation is a hallmark effect of adaptive cognitive control and refers to the adjustment of control to the level of previously experienced conflict. Conflict monitoring theory assumes that the dorsolateral prefrontal cortex (DLPFC) is causally involved in this adjustment. However, to date, evidence in humans is predominantly correlational, and heterogeneous with respect to the lateralization of control in the DLPFC. We used high-definition transcranial direct current stimulation (HD-tDCS), which allows for more focal current delivery than conventional tDCS, to clarify the causal involvement of the DLPFC in conflict adaptation. Specifically, we investigated the regional specificity and lateralization of potential beneficial stimulation effects on conflict adaptation during a visual flanker task. One hundred twenty healthy participants were assigned to four HD-tDCS conditions: left or right DLPFC or left or right primary motor cortex (M1). Each group underwent both active and sham HD-tDCS in crossover, double-blind designs. We obtained a sizeable conflict adaptation effect (measured as the modulation of the flanker effect as a function of previous response conflict) in all groups and conditions. However, this effect was larger under active HD-tDCS than under sham stimulation in both DLPFC groups. In contrast, active stimulation had no effect on conflict adaptation in the M1 groups. In sum, the present results indicate that the DLPFC plays a causal role in adaptive cognitive control, but that the involvement of DLPFC in control is not restricted to the left or right hemisphere. Moreover, our study confirms the potential of HD-tDCS to modulate cognition in a regionally specific manner.

  13. Cognitive Dysfunction in Major Depressive Disorder. A Translational Review in Animal Models of the Disease.

    Science.gov (United States)

    Darcet, Flavie; Gardier, Alain M; Gaillard, Raphael; David, Denis J; Guilloux, Jean-Philippe

    2016-02-17

    Major Depressive Disorder (MDD) is the most common psychiatric disease, affecting millions of people worldwide. In addition to the well-defined depressive symptoms, patients suffering from MDD consistently complain about cognitive disturbances, significantly exacerbating the burden of this illness. Among cognitive symptoms, impairments in attention, working memory, learning and memory or executive functions are often reported. However, available data about the heterogeneity of MDD patients and magnitude of cognitive symptoms through the different phases of MDD remain difficult to summarize. Thus, the first part of this review briefly overviewed clinical studies, focusing on the cognitive dysfunctions depending on the MDD type. As animal models are essential translational tools for underpinning the mechanisms of cognitive deficits in MDD, the second part of this review synthetized preclinical studies observing cognitive deficits in different rodent models of anxiety/depression. For each cognitive domain, we determined whether deficits could be shared across models. Particularly, we established whether specific stress-related procedures or unspecific criteria (such as species, sex or age) could segregate common cognitive alteration across models. Finally, the role of adult hippocampal neurogenesis in rodents in cognitive dysfunctions during MDD state was also discussed.

  14. Modelling of helical current filaments induced by LHW on EAST

    Energy Technology Data Exchange (ETDEWEB)

    Rack, Michael; Denner, Peter; Liang, Yunfeng [Institute of Energy and Climate Research - Plasma Physics, Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, Partner in the Trilateral Euregio Cluster, D-52425 Juelich (Germany); Zeng, Long [Institute of Energy and Climate Research - Plasma Physics, Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, Partner in the Trilateral Euregio Cluster, D-52425 Juelich (Germany); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Gong, Xianzu; Gan, Kaifu; Wang, Liang; Liu, Fukun; Qian, Jinping; Shen, Biao; Li, Jiangang [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Gauthier, Eric [Association EURATOM-CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Collaboration: the EAST Team

    2013-07-01

    Helical radiation belts have been observed in the scrape-off layer (SOL) of the plasma during the application of lower hybrid wave (LHW) heating at the superconducting tokamak EAST. Modelled SOL field lines, starting in-front of the LHW antennas, show agreement in position and pitch angle to the experimental observed radiation belts. A splitting of the strike-line can be observed on the outer divertor plates during the application of LHW heating. Agreement in the comparison of the Mirnov coil signals and a modelled electric current flow along these SOL field lines was found. A lower hybrid current drive can induce such an electric current flow near the plasma edge. This electric current flow causes a change of the plasma topology which could result in the splitting of the strike-line as known from the application of resonant magnetic perturbation fields. Comparisons of modelled footprint structures and experimental observed heat load patterns in the divertor region are discussed.

  15. Cognitive Process Modeling of Spatial Ability: The Assembling Objects Task

    Science.gov (United States)

    Ivie, Jennifer L.; Embretson, Susan E.

    2010-01-01

    Spatial ability tasks appear on many intelligence and aptitude tests. Although the construct validity of spatial ability tests has often been studied through traditional correlational methods, such as factor analysis, less is known about the cognitive processes involved in solving test items. This study examines the cognitive processes involved in…

  16. Dynamics, models, and mechanisms of the cognitive flexibility of preschoolers

    NARCIS (Netherlands)

    van Bers, B.M.C.W.

    2014-01-01

    Flexibility is a significant ability in the present rapidly changing society. In a novel situation or when circumstances change, one’s automatic inclinations provide no guidance, and conscious cognitive control is required. Cognitive flexibility is one of the component abilities that constitute cogn

  17. Multiscale Modeling of Gene-Behavior Associations in an Artificial Neural Network Model of Cognitive Development.

    Science.gov (United States)

    Thomas, Michael S C; Forrester, Neil A; Ronald, Angelica

    2016-01-01

    In the multidisciplinary field of developmental cognitive neuroscience, statistical associations between levels of description play an increasingly important role. One example of such associations is the observation of correlations between relatively common gene variants and individual differences in behavior. It is perhaps surprising that such associations can be detected despite the remoteness of these levels of description, and the fact that behavior is the outcome of an extended developmental process involving interaction of the whole organism with a variable environment. Given that they have been detected, how do such associations inform cognitive-level theories? To investigate this question, we employed a multiscale computational model of development, using a sample domain drawn from the field of language acquisition. The model comprised an artificial neural network model of past-tense acquisition trained using the backpropagation learning algorithm, extended to incorporate population modeling and genetic algorithms. It included five levels of description-four internal: genetic, network, neurocomputation, behavior; and one external: environment. Since the mechanistic assumptions of the model were known and its operation was relatively transparent, we could evaluate whether cross-level associations gave an accurate picture of causal processes. We established that associations could be detected between artificial genes and behavioral variation, even under polygenic assumptions of a many-to-one relationship between genes and neurocomputational parameters, and when an experience-dependent developmental process interceded between the action of genes and the emergence of behavior. We evaluated these associations with respect to their specificity (to different behaviors, to function vs. structure), to their developmental stability, and to their replicability, as well as considering issues of missing heritability and gene-environment interactions. We argue that gene

  18. The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence From Word Segmentation

    National Research Council Canada - National Science Library

    Phillips, Lawrence; Pearl, Lisa

    2015-01-01

    The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's cognitive plausibility...

  19. Novel Virtual User Models of Mild Cognitive Impairment for Simulating Dementia

    Directory of Open Access Journals (Sweden)

    Sofia Segkouli

    2015-01-01

    Full Text Available Virtual user modeling research has attempted to address critical issues of human-computer interaction (HCI such as usability and utility through a large number of analytic, usability-oriented approaches as cognitive models in order to provide users with experiences fitting to their specific needs. However, there is demand for more specific modules embodied in cognitive architecture that will detect abnormal cognitive decline across new synthetic task environments. Also, accessibility evaluation of graphical user interfaces (GUIs requires considerable effort for enhancing ICT products accessibility for older adults. The main aim of this study is to develop and test virtual user models (VUM simulating mild cognitive impairment (MCI through novel specific modules, embodied at cognitive models and defined by estimations of cognitive parameters. Well-established MCI detection tests assessed users’ cognition, elaborated their ability to perform multitasks, and monitored the performance of infotainment related tasks to provide more accurate simulation results on existing conceptual frameworks and enhanced predictive validity in interfaces’ design supported by increased tasks’ complexity to capture a more detailed profile of users’ capabilities and limitations. The final outcome is a more robust cognitive prediction model, accurately fitted to human data to be used for more reliable interfaces’ evaluation through simulation on the basis of virtual models of MCI users.

  20. The Importance of Cognitive Phenotypes in Experimental Modeling of Animal Anxiety and Depression

    OpenAIRE

    Kalueff, Allan V.; Murphy, Dennis L.

    2007-01-01

    Cognitive dysfunctions are commonly seen in many stress-related disorders, including anxiety and depression—the world's most common neuropsychiatric illnesses. Various genetic, pharmacological, and behavioral animal models have long been used to establish animal anxiety-like and depression-like phenotypes, as well as to assess their memory, learning, and other cognitive functions. Mounting clinical and animal evidences strongly supports the notion that disturbed cognitions represent an import...

  1. Merging imagery and models for river current prediction

    Science.gov (United States)

    Blain, Cheryl Ann; Linzell, Robert S.; McKay, Paul

    2011-06-01

    To meet the challenge of operating in river environments with denied access and to improve the riverine intelligence available to the warfighter, advanced high resolution river circulation models are combined with remote sensing feature extraction algorithms to produce a predictive capability for currents and water levels in rivers where a priori knowledge of the river environment is limited. A River Simulation Tool (RST) is developed to facilitate the rapid configuration of a river model. River geometry is extracted from the automated processing of available imagery while minimal user input is collected to complete the parameter and forcing specifications necessary to configure a river model. Contingencies within the RST accommodate missing data such as a lack of water depth information and allow for ensemble computations. Successful application of the RST to river environments is demonstrated for the Snohomish River, WA. Modeled currents compare favorably to in-situ currents reinforcing the value of the developed approach.

  2. A Neuron Model Based Ultralow Current Sensor System for Bioapplications

    Directory of Open Access Journals (Sweden)

    A. K. M. Arifuzzman

    2016-01-01

    Full Text Available An ultralow current sensor system based on the Izhikevich neuron model is presented in this paper. The Izhikevich neuron model has been used for its superior computational efficiency and greater biological plausibility over other well-known neuron spiking models. Of the many biological neuron spiking features, regular spiking, chattering, and neostriatal spiny projection spiking have been reproduced by adjusting the parameters associated with the model at hand. This paper also presents a modified interpretation of the regular spiking feature in which the firing pattern is similar to that of the regular spiking but with improved dynamic range offering. The sensor current ranges between 2 pA and 8 nA and exhibits linearity in the range of 0.9665 to 0.9989 for different spiking features. The efficacy of the sensor system in detecting low amount of current along with its high linearity attribute makes it very suitable for biomedical applications.

  3. Formulation of a Medical Food Cocktail for Alzheimer's Disease: Beneficial Effects on Cognition and Neuropathology in a Mouse Model of the Disease

    OpenAIRE

    2010-01-01

    BACKGROUND: Dietary supplements have been extensively studied for their beneficial effects on cognition and AD neuropathology. The current study examines the effect of a medical food cocktail consisting of the dietary supplements curcumin, piperine, epigallocatechin gallate, α-lipoic acid, N-acetylcysteine, B vitamins, vitamin C, and folate on cognitive functioning and the AD hallmark features and amyloid-beta (Aβ) in the Tg2576 mouse model of the disease. PRINCIPAL FINDINGS: The study found ...

  4. MODEL STUDY OF THE DOUBLE FED MACHINE WITH CURRENT CONTROL

    Directory of Open Access Journals (Sweden)

    A. S. Lyapin

    2016-07-01

    Full Text Available The paper deals with modeling results of the double fed induction machine with current control in the rotor circuit. We show the most promising applications of electric drives on the basis of the double fed induction machine and their advantages. We present and consider functional scheme of the electric drive on the basis of the double fed induction machine with current control. Equations are obtained for creation of such machine mathematical model. Expressions for vector projections of rotor current are given. According to the obtained results, the change of the vector projections of rotor current ensures operation of the double fed induction machine with the specified values of active and reactive stator power throughout the variation range of sliding motion. We consider static characteristics of double fed machine with current control. Energy processes proceeding in the machine are analyzed. We confirm the operationpossibility of double fed induction machine with current controlin the rotor circuit with given values of active and reactive stator power. The presented results can be used for creation of mathematical models and static characteristics of double fed machines with current control of various capacities.

  5. Flavour-changing neutral currents in models with extra ' boson

    Indian Academy of Sciences (India)

    S Sahoo; L Maharana

    2004-09-01

    New neutral gauge bosons ' are the features of many models addressing the physics beyond the standard model. Together with the existence of new neutral gauge bosons, models based on extended gauge groups (rank > 4) often predict new charged fermions also. A mixing of the known fermions with new states, with exotic weak-isospin assignments (left-handed singlets and right-handed doublets) will induce tree-level flavour-changing neutral interactions mediated by exchange, while if the mixing is only with new states with ordinary weak-isospin assignments, the flavour-changing neutral currents are mainly due to the exchange of the new neutral gauge boson '. We review flavour-changing neutral currents in models with extra ' boson. Then we discuss some flavour-changing processes forbidden in the standard model and new contributions to standard model processes.

  6. Cognitive Model and Cognitive Load Evaluation of Information Retrieval%信息检索认知模型及认知负荷评价研究

    Institute of Scientific and Technical Information of China (English)

    刘佳; 沈旺; 李贺

    2012-01-01

    通过对信息检索认知理论的研究,构建信息检索认知模型。依据信息检索认知模型及认知负荷理论,构建信息检索认知过程中认知负荷结构模型,并提出认知负荷评价的基本框架。通过实证研究,对数字图书馆信息检索认知过程中的认知负荷进行评价并指出其动态变化。%This paper defines the user cognitive model of information retrieval through the analysis of cognitive theory. Based on the cognitive model of information retrieval and cognitive load theory, it constructs the structural model of the cognitive load in the cognitive processes of information retrieval and the cognitive load framework. It evaluates information retrieval of digital library in the cognitive processes of cognitive load by empirical research, and pointes out that the cognitive load dynamically changes in the cognitive process of information retrieval.

  7. Joint modeling for cognitive trajectory and risk of dementia in the presence of death.

    Science.gov (United States)

    Yu, Binbing; Ghosh, Pulak

    2010-03-01

    Dementia is characterized by accelerated cognitive decline before and after diagnosis as compared to normal aging. It has been known that cognitive impairment occurs long before the diagnosis of dementia. For individuals who develop dementia, it is important to determine the time when the rate of cognitive decline begins to accelerate and the subsequent gap time to dementia diagnosis. For normal aging individuals, it is also useful to understand the trajectory of cognitive function until their death. A Bayesian change-point model is proposed to fit the trajectory of cognitive function for individuals who develop dementia. In real life, people in older ages are subject to two competing risks, e.g., dementia and dementia-free death. Because the majority of people do not develop dementia, a mixture model is used for survival data with competing risks, which consists of dementia onset time after the change point of cognitive function decline for demented individuals and death time for nondemented individuals. The cognitive trajectories and the survival process are modeled jointly and the parameters are estimated using the Markov chain Monte Carlo method. Using data from the Honolulu Asia Aging Study, we show the trajectories of cognitive function and the effect of education, apolipoprotein E 4 genotype, and hypertension on cognitive decline and the risk of dementia.

  8. Modeling the Inner Magnetosphere: Radiation Belts, Ring Current, and Composition

    Science.gov (United States)

    Glocer, Alex

    2011-01-01

    The space environment is a complex system defined by regions of differing length scales, characteristic energies, and physical processes. It is often difficult, or impossible, to treat all aspects of the space environment relative to a particular problem with a single model. In our studies, we utilize several models working in tandem to examine this highly interconnected system. The methodology and results will be presented for three focused topics: 1) Rapid radiation belt electron enhancements, 2) Ring current study of Energetic Neutral Atoms (ENAs), Dst, and plasma composition, and 3) Examination of the outflow of ionospheric ions. In the first study, we use a coupled MHD magnetosphere - kinetic radiation belt model to explain recent Akebono/RDM observations of greater than 2.5 MeV radiation belt electron enhancements occurring on timescales of less than a few hours. In the second study, we present initial results of a ring current study using a newly coupled kinetic ring current model with an MHD magnetosphere model. Results of a dst study for four geomagnetic events are shown. Moreover, direct comparison with TWINS ENA images are used to infer the role that composition plays in the ring current. In the final study, we directly model the transport of plasma from the ionosphere to the magnetosphere. We especially focus on the role of photoelectrons and and wave-particle interactions. The modeling methodology for each of these studies will be detailed along with the results.

  9. Information theory-based approach for modeling the cognitive behavior of NPP operators

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun; Seong, Poong Hyun [KAIST, Taejon (Korea, Republic of)

    2001-10-01

    An NPP system consists of three important components: the machine system, operators, and MMI. Through the MMI, operators monitor and control the plant system. The cognitive model of NPP operators has become a target of modeling by cognitive engineers due to their work environment: complex, uncertain, and safe critical. We suggested the contextual model for the cognitive behavior of NPP operator and the mathematical fundamentals based on information theory which can quantify the model. The demerit of the methodology using the information theory is that it cannot evaluate the correctness and quality of information. Therefore, the validation through the experiment is needed.

  10. Neural Network based Modeling and Simulation of Transformer Inrush Current

    Directory of Open Access Journals (Sweden)

    Puneet Kumar Singh

    2012-05-01

    Full Text Available Inrush current is a very important phenomenon which occurs during energization of transformer at no load due to temporary over fluxing. It depends on several factors like magnetization curve, resistant and inductance of primary winding, supply frequency, switching angle of circuit breaker etc. Magnetizing characteristics of core represents nonlinearity which requires improved nonlinearity solving technique to know the practical behavior of inrush current. Since several techniques still working on modeling of transformer inrush current but neural network ensures exact modeling with experimental data. Therefore, the objective of this study was to develop an Artificial Neural Network (ANN model based on data of switching angle and remanent flux for predicting peak of inrush current. Back Propagation with Levenberg-Marquardt (LM algorithm was used to train the ANN architecture and same was tested for the various data sets. This research work demonstrates that the developed ANN model exhibits good performance in prediction of inrush current’s peak with an average of percentage error of -0.00168 and for modeling of inrush current with an average of percentage error of -0.52913.

  11. Development of Web-Based Learning Environment Model to Enhance Cognitive Skills for Undergraduate Students in the Field of Electrical Engineering

    Science.gov (United States)

    Lakonpol, Thongmee; Ruangsuwan, Chaiyot; Terdtoon, Pradit

    2015-01-01

    This research aimed to develop a web-based learning environment model for enhancing cognitive skills of undergraduate students in the field of electrical engineering. The research is divided into 4 phases: 1) investigating the current status and requirements of web-based learning environment models. 2) developing a web-based learning environment…

  12. Transcranial Direct Current Stimulation Effects on Athletes’ Cognitive Performance: An Exploratory Proof of Concept Trial

    Directory of Open Access Journals (Sweden)

    Davimar Borduchi

    2016-11-01

    Full Text Available Among the 2016 Olympic and Paralympic Games unforgettable moments, one could not overlook performances by Phelps and Bolt, which challenge old premises about the maximum extension of individual supremacism in ultracompetitive modalities and the doping scandals. Different media channels resonated these two trends, with an unseen rise on discussions about traits and practices that may set ultrahigh performance athletes apart from the more ordinary ones. Yet, some key issues remain undebated. This paper aims to add to this debate, with a proof of concept trial, which investigates whether tDCS may serve as an aid for professional athletes. Ten professional athletes of three different modalities of (judo, N=4 athletes, swimming, N=3 athletes and rhythmic gymnastics, N=3 athletes received anodal stimulation (2mA for 20 minutes on the left dorsolateral prefrontal cortex for ten consecutive weekdays. We observed a positive effect of tDCS in their cognitive performance, including a significant improvement in alternated, sustained and divided attention and in memory scores. We also observed a decrease in Beck Depression Inventory scores (4.50 points in this non-clinical population. These preliminary results suggest that tDCS sessions may translate into competitive advantages for professional athletes and recommend the deepening of the discussion on its ethical use in sports, which is ultimately tied to the wider debate around the risks and opportunities that neuromodulation brings to the table.

  13. Meson Exchange Current (MEC) Models in Neutrino Interaction Generators

    CERN Document Server

    Katori, Teppei

    2013-01-01

    Understanding of the so-called 2 particle-2 hole (2p-2h) effect is an urgent program in neutrino interaction physics for current and future oscillation experiments. Such processes are believed to be responsible for the event excesses observed by recent neutrino experiments. The 2p-2h effect is dominated by the meson exchange current (MEC), and is accompanied by a 2-nucleon emission from the primary vertex, instead of a single nucleon emission from the charged-current quasi-elastic (CCQE) interaction. Current and future high resolution experiments can potentially nail down this effect. For this reason, there are world wide efforts to model and implement this process in neutrino interaction simulations. In these proceedings, I would like to describe how this channel is modeled in neutrino interaction generators.

  14. An improved cognitive model of the Iowa and Soochow Gambling Tasks with regard to model fitting performance and tests of parameter consistency

    Science.gov (United States)

    Dai, Junyi; Kerestes, Rebecca; Upton, Daniel J.; Busemeyer, Jerome R.; Stout, Julie C.

    2015-01-01

    The Iowa Gambling Task (IGT) and the Soochow Gambling Task (SGT) are two experience-based risky decision-making tasks for examining decision-making deficits in clinical populations. Several cognitive models, including the expectancy-valence learning (EVL) model and the prospect valence learning (PVL) model, have been developed to disentangle the motivational, cognitive, and response processes underlying the explicit choices in these tasks. The purpose of the current study was to develop an improved model that can fit empirical data better than the EVL and PVL models and, in addition, produce more consistent parameter estimates across the IGT and SGT. Twenty-six opiate users (mean age 34.23; SD 8.79) and 27 control participants (mean age 35; SD 10.44) completed both tasks. Eighteen cognitive models varying in evaluation, updating, and choice rules were fit to individual data and their performances were compared to that of a statistical baseline model to find a best fitting model. The results showed that the model combining the prospect utility function treating gains and losses separately, the decay-reinforcement updating rule, and the trial-independent choice rule performed the best in both tasks. Furthermore, the winning model produced more consistent individual parameter estimates across the two tasks than any of the other models. PMID:25814963

  15. An Improved Cognitive Model of the Iowa and Soochow Gambling Tasks With Regard to Model Fitting Performance and Tests of Parameter Consistency

    Directory of Open Access Journals (Sweden)

    Junyi eDai

    2015-03-01

    Full Text Available The Iowa Gambling Task (IGT and the Soochow Gambling Task (SGT are two experience-based risky decision-making tasks for examining decision-making deficits in clinical populations. Several cognitive models, including the expectancy-valence learning model (EVL and the prospect valence learning model (PVL, have been developed to disentangle the motivational, cognitive, and response processes underlying the explicit choices in these tasks. The purpose of the current study was to develop an improved model that can fit empirical data better than the EVL and PVL models and, in addition, produce more consistent parameter estimates across the IGT and SGT. Twenty-six opiate users (mean age 34.23; SD 8.79 and 27 control participants (mean age 35; SD 10.44 completed both tasks. Eighteen cognitive models varying in evaluation, updating, and choice rules were fit to individual data and their performances were compared to that of a statistical baseline model to find a best fitting model. The results showed that the model combining the prospect utility function treating gains and losses separately, the decay-reinforcement updating rule, and the trial-independent choice rule performed the best in both tasks. Furthermore, the winning model produced more consistent individual parameter estimates across the two tasks than any of the other models.

  16. Community Benchmarking of Tsunami-Induced Nearshore Current Models

    Science.gov (United States)

    Lynett, P. J.; Wilson, R. I.; Gately, K.

    2015-12-01

    To help produce accurate and consistent maritime hazard products, the National Tsunami Hazard Mitigation Program (NTHMP) Strategic Plan includes a requirement to develop and run a benchmarking workshop to evaluate the numerical tsunami modeling of currents. For this workshop, five different benchmarking datasets were organized. These datasets were selected based on characteristics such as geometric complexity, currents that are shear/separation driven (and thus are de-coupled from the incident wave forcing), tidal coupling, and interaction with the built environment. While tsunami simulation models have generally been well validated against wave height and runup, comparisons with speed data are much less common. As model results are increasingly being used to estimate or indicate damage to coastal infrastructure, understanding the accuracy and precision of speed predictions becomes of important. As a result of this 2-day workshop held in early 2015, modelers now have a better awareness of their ability to accurately capture the physics of tsunami currents, and therefore a better understanding of how to use these simulation tools for hazard assessment and mitigation efforts. In this presentation, the model results - from 14 different modelers - will be presented and summarized, with a focus on statistical and ensemble properties of the current predictions.

  17. Probability of detection models for eddy current NDE methods

    Energy Technology Data Exchange (ETDEWEB)

    Rajesh, S.N.

    1993-04-30

    The development of probability of detection (POD) models for a variety of nondestructive evaluation (NDE) methods is motivated by a desire to quantify the variability introduced during the process of testing. Sources of variability involved in eddy current methods of NDE include those caused by variations in liftoff, material properties, probe canting angle, scan format, surface roughness and measurement noise. This thesis presents a comprehensive POD model for eddy current NDE. Eddy current methods of nondestructive testing are used widely in industry to inspect a variety of nonferromagnetic and ferromagnetic materials. The development of a comprehensive POD model is therefore of significant importance. The model incorporates several sources of variability characterized by a multivariate Gaussian distribution and employs finite element analysis to predict the signal distribution. The method of mixtures is then used for estimating optimal threshold values. The research demonstrates the use of a finite element model within a probabilistic framework to the spread in the measured signal for eddy current nondestructive methods. Using the signal distributions for various flaw sizes the POD curves for varying defect parameters have been computed. In contrast to experimental POD models, the cost of generating such curves is very low and complex defect shapes can be handled very easily. The results are also operator independent.

  18. Race-related cognitive test bias in the active study: a mimic model approach.

    Science.gov (United States)

    Aiken Morgan, Adrienne T; Marsiske, Michael; Dzierzewski, Joseph M; Jones, Richard N; Whitfield, Keith E; Johnson, Kathy E; Cresci, Mary K

    2010-10-01

    The present study investigated evidence for race-related test bias in cognitive measures used in the baseline assessment of the ACTIVE clinical trial. Test bias against African Americans has been documented in both cognitive aging and early life span studies. Despite significant mean performance differences, Multiple Indicators Multiple Causes (MIMIC) models suggested most differences were at the construct level. There was little evidence that specific measures put either group at particular advantage or disadvantage and little evidence of cognitive test bias in this sample. Small group differences in education, cognitive status, and health suggest positive selection may have attenuated possible biases.

  19. Modeling neurodevelopmental cognitive deficits in tasks with cross-species translational validity.

    Science.gov (United States)

    Cope, Z A; Powell, S B; Young, J W

    2016-01-01

    Numerous psychiatric disorders whose cognitive dysfunction links to functional outcome have neurodevelopmental origins including schizophrenia, autism and bipolar disorder. Treatments are needed for these cognitive deficits, which require development using animal models. Models of neurodevelopmental disorders are as varied and diverse as the disorders themselves, recreating some but not all aspects of the disorder. This variety may in part underlie why purported procognitive treatments translated from these models have failed to restore functioning in the targeted patient populations. Further complications arise from environmental factors used in these models that can contribute to numerous disorders, perhaps only impacting specific domains, while diagnostic boundaries define individual disorders, limiting translational efficacy. The Research Domain Criteria project seeks to 'develop new ways to classify mental disorders based on behavioral dimensions and neurobiological measures' in hopes of facilitating translational research by remaining agnostic toward diagnostic borders derived from clinical presentation in humans. Models could therefore recreate biosignatures of cognitive dysfunction irrespective of disease state. This review highlights work within the field of neurodevelopmental models of psychiatric disorders tested in cross-species translational cognitive paradigms that directly inform this newly developing research strategy. By expounding on this approach, the hopes are that a fuller understanding of each model may be attainable in terms of the cognitive profile elicited by each manipulation. Hence, conclusions may begin to be drawn on the nature of cognitive neuropathology on neurodevelopmental and other disorders, increasing the chances of procognitive treatment development for individuals affected in specific cognitive domains.

  20. Modeling cognitive trajectories within longitudinal studies: a focus on older adults.

    Science.gov (United States)

    Steinerman, Joshua R; Hall, Charles B; Sliwinski, Martin J; Lipton, Richard B

    2010-10-01

    The natural history of life span cognitive performance and its late-life determinants have been studied from an array of perspectives. Significant insights come from psychological disciplines, including cognitive, developmental, and neuropsychology, as well as from medical specialties, such as geriatrics, neurology, psychiatry, neuroradiology, and neuropathology, that contribute to the growing interdisciplinary scientific field: cognitive neuroscience of aging. This survey of longitudinal studies of aging suggests that disease-oriented investigations commonly do not adequately consider normative cognitive changes, whereas developmental studies do not sufficiently measure and model nonnormative cognitive aging. This article argues for an integrative perspective that considers both of these influences on cognitive trajectories and presents a series of methodological concerns that have not been addressed comprehensively. Interdisciplinary methods from longitudinal observational studies should be leveraged to enable translational interventions to promote brain longevity.

  1. PET Evidence of the Effect of Donepezil on Cognitive Performance in an Animal Model of Chemobrain

    Directory of Open Access Journals (Sweden)

    Ilhan Lim

    2016-01-01

    Full Text Available A considerable number of patients with breast cancer complain of cognitive impairment after chemotherapy. In this study, we showed that donepezil enhanced memory function and increased brain glucose metabolism in a rat model of cognitive impairment after chemotherapy using behavioral analysis and positron emission tomography (PET. We found that chemotherapy affected spatial learning ability, reference memory, and working memory and that donepezil improved these cognitive impairments. According to PET analysis, chemotherapy reduced glucose metabolism in the medial prefrontal cortex and hippocampus, and donepezil increased glucose metabolism in the bilateral frontal lobe, parietal lobe, and hippocampus. Reduced glucose metabolism was more prominent after treatment with doxorubicin than cyclophosphamide. Our results demonstrated the neural mechanisms for cognitive impairment after chemotherapy and show that cognition was improved after donepezil intervention using both behavioral and imaging methods. Our results suggested that donepezil can be employed clinically for the treatment of cognitive deficits after chemotherapy.

  2. Have Cognitive Diagnostic Models Delivered Their Goods? Some Substantial and Methodological Concerns

    Science.gov (United States)

    Wilhelm, Oliver; Robitzsch, Alexander

    2009-01-01

    The paper by Rupp and Templin (2008) is an excellent work on the characteristics and features of cognitive diagnostic models (CDM). In this article, the authors comment on some substantial and methodological aspects of this focus paper. They organize their comments by going through issues associated with the terms "cognitive," "diagnostic" and…

  3. On the scientific status of cognitive appraisal models of anxiety disorder.

    Science.gov (United States)

    McNally, R J

    2001-05-01

    The cognitive paradigm for understanding and treating anxiety disorders comprises two distinct and potentially incompatible approaches: appraisal and information-processing. Advocates of the latter approach have sharply criticized the scientific adequacy of the appraisal models popularized by cognitive therapists. The purpose of this essay is to provide a reappraisal of these critiques of appraisal, and to defend an argument for methodological pluralism.

  4. Longitudinal Test of a Social Cognitive Model of Academic and Life Satisfaction

    Science.gov (United States)

    Singley, Daniel B.; Lent, Robert W.; Sheu, Hung-Bin

    2010-01-01

    The authors tested a social cognitive model of academic and overall life satisfaction in a sample of 769 university students. The predictors, drawn from Lent's unifying perspective on well-being and psychosocial adjustment, included social cognitive (academic self-efficacy, goal progress, social support) and personality (trait positive affect)…

  5. Helpful Components Involved in the Cognitive-Experiential Model of Dream Work

    Science.gov (United States)

    Tien, Hsiu-Lan Shelley; Chen, Shuh-Chi; Lin, Chia-Huei

    2009-01-01

    The purpose of the study was to examine the helpful components involved in the Hill's cognitive-experiential dream work model. Participants were 27 volunteer clients from colleges and universities in northern and central parts of Taiwan. Each of the clients received 1-2 sessions of dream interpretations. The cognitive-experiential dream work model…

  6. Supervision of Group Work: A Model to Increase Supervisee Cognitive Complexity

    Science.gov (United States)

    Granello, Darcy Haag; Underfer-Babalis, Jean

    2004-01-01

    This article describes a model for supervisors of group counselors to use to promote cognitive complexity in their supervisees. Counselor cognitive complexity has been linked to many positive counseling skills, including greater flexibility, empathy, confidence, and client conceptualization. Bloom's Taxonomy of Educational Objectives provides a…

  7. Measures and Models for Estimating and Predicting Cognitive Fatigue

    Science.gov (United States)

    Trejo, Leonard J.; Kochavi, Rebekah; Kubitz, Karla; Montgomery, Leslie D.; Rosipal, Roman; Matthews, Bryan

    2004-01-01

    We analyzed EEG and ERPs in a fatiguing mental task and created statistical models for single subjects. Seventeen subjects (4 F, 18-38 y) viewed 4-digit problems (e.g., 3+5-2+7=15) on a computer, solved the problems, and pressed keys to respond (intertrial interval = 1 s). Subjects performed until either they felt exhausted or three hours had elapsed. Re- and post-task measures of mood (Activation Deactivation Adjective Checklist, Visual Analogue Mood Scale) confirmed that fatigue increased and energy decreased over time. We tested response times (RT); amplitudes of ERP components N1, P2, P300, readiness potentials; and amplitudes of frontal theta and parietal alpha rhythms for change as a function of time. For subjects who completed 3 h (n=9) we analyzed 12 15-min blocks. For subjects who completed at least 1.5 h (n=17), we analyzed the first-, middle-, and last 100 error-free trials. Mean RT rose from 6.7 s to 8.5 s over time. We found no changes in the amplitudes of ERP components. In both analyses, amplitudes of frontal theta and parietal alpha rose by 30% or more over time. We used 30-channel EEG frequency spectra to model the effects of time in single subjects using a kernel partial least squares classifier. We classified 3.5s EEG segments as being from the first 100 or the last 100 trials, using random sub-samples of each class. Test set accuracies ranged from 63.9% to 99.6% correct. Only 2 of 17 subjects had mean accuracies lower than 80%. The results suggest that EEG accurately classifies periods of cognitive fatigue in 90% of subjects.

  8. A Cross-Cultural Study of the Cognitive Model of Depression: Cognitive Experiences Converge between Egypt and Canada

    Science.gov (United States)

    Beshai, Shadi; Dobson, Keith S; Adel, Ashraf; Hanna, Niveen

    2016-01-01

    Introduction Models of depression that arise in the West need to be examined in other regions of the world. This study examined a set of foundational hypotheses generated by Beck’s cognitive model of depression among depressed individuals in Egypt and Canada. Method We recruited 29 depressed and 29 non-depressed Egyptians and compared their results with those of 35 depressed and 38 non-depressed Canadians. Depression status was ascertained using a structured interview, scores on the Beck Depression Inventory, and scores on the Psychiatric Diagnostic Screening Questionnaire. Participants completed questionnaires designed to measure the frequency of negative and positive automatic thoughts (ATQ–N, BHS, and ATQ–P), and dysfunctional attitudes (DAS). Results Depressed individuals in both countries had significantly more negative thoughts about self and future, greater frequency of dysfunctional attitudes, and diminished positive self-thoughts in comparison to non-depressed individuals. Egyptians generally showed significantly more dysfunctional attitudes than their Canadian counterparts. Discussion The four hypotheses that were tested were supported among the depressed Egyptian sample, which is consistent with the cognitive model. Implications for the cognitive-behavioral model and treatment for this group of sufferers are discussed. PMID:27010706

  9. Model of Cognitive Readiness of Musical Education Students

    Directory of Open Access Journals (Sweden)

    Almagul T. Ermuratova

    2014-05-01

    Full Text Available The article features scientific studies on cognitive readiness of musical education students. The author, in the course of his study, focuses on ideas and experience of folk pedagogy. In the course of the study, the author determines criteria and elements of cognitive readiness. The key achievement of the article is an identification of three possible levels of students’ cognitive readiness. The author concludes that establishment of cognitive activities of future music teachers, comes from their knowledge pedagogical principles, pedagogical principles of educational unity, fostering and development of human being, consistency and sequence, identification of pedagogical approaches with regard to individual peculiarities of students and professional pedagogical interaction between teachers and students.

  10. Flavor Changing Neutral Currents in a Realistic Composite Technicolor Model

    CERN Document Server

    Carone, C D; Carone, Christopher D.; Hamilton, Rowan T.

    1993-01-01

    We consider the phenomenology of a composite technicolor model proposed recently by Georgi. Composite technicolor interactions produce four-quark operators in the low energy theory that contribute to flavor changing neutral current processes. While we expect operators of this type to be induced at the compositeness scale by the flavor-symmetry breaking effects of the preon mass matrices, the Georgi model also includes operators from higher scales that are not GIM-suppressed. Since these operators are potentially large, we study their impact on flavor changing neutral currents and CP violation in the neutral $B$, $D$, and $K$ meson systems.

  11. Chronic obstructive pulmonary disease. An original model of cognitive decline.

    Science.gov (United States)

    Incalzi, R A; Gemma, A; Marra, C; Muzzolon, R; Capparella, O; Carbonin, P

    1993-08-01

    In order to characterize the neuropsychologic profile of patients with hypoxic-hypercapnic chronic obstructive pulmonary disease (COPD), the performance of 36 patients with COPD 69 +/- 10 yr of age (mean +/- SD) on 19 tests exploring eight cognitive domains was compared with those of 29 normal adults (69 +/- 7 yr of age), 20 normal elderly adults (78 +/- 2 yr of age), 26 patients with Alzheimer-type dementia (72 +/- 6 yr of age), and 28 with multi-infarct dementia (MID) (70 +/- 8 yr of age). The discriminant analysis of cognitive test scores showed that 48.5% of patients with COPD had a specific pattern of cognitive deterioration characterized by a dramatic impairment in verbal and verbal memory tasks, well-preserved visual attention, and diffuse worsening of the other functions. The remaining patients with COPD were functionally classified as normal adults (12.1%), normal elderly adults (15.2%), those with MID (12.1%), and those with Alzheimer-type dementia (12.1%) according to discriminant analysis. Cognitive impairment was significantly and positively correlated with age (p analogies between age-related and COPD-related cognitive decline are evident, a distinct cognitive profile was found in a large fraction of patients with COPD and it differs in several aspects from those of both normal and demented subjects.

  12. Description of Self-efficacy and Initial Cognitive Abilities on the Students’ Physics Learning of the Direct Current Electrical Circuits

    Science.gov (United States)

    Zaenudin; Maknun, J.; Muslim

    2017-03-01

    This study aims to determine description of self -efficacy and initial cognitive abilities on the students of MAN 1 Bandung (senior high school) in learning physics on the subject of electrical circuits Direct Current (DC) before they get academy ask assigned in the classroom. From the results of this research can be used as a reference to provide appropriate measures for the advancement of student learning. The theory used in this research is the theory of Bandura. The design in this study using case study and data collection is done by tests and questionnaires, sampling techniques used by random sampling, the study was conducted on 10th grade students of MAN 1 Bandung by the amount of students 35 participants. The results of data analysis showed that the percentage of students who have moderate self-efficacy amounted to 67.05 %, and cognitive ability 50 %, this shows that the process of learning that takes place in school before that junior high school is not much scientific implement processes that provide students the opportunity to discover new things, then learning approaches of right is Problem Based Learning (PBL).

  13. A Content Analysis of Television Ads: Does Current Practice Maximize Cognitive Processing?

    Science.gov (United States)

    2008-12-11

    chocolate candy (see Appendix D). The current study also included diet, low fat, and lean varieties of the products just listed as they are likely to...PCT condition (e.g., an ad for a loved brand of chocolate that employed sexual imagery) would demand more processing resources than messages using...M. A. (1986). Analogies , visualization, and mental processing of science stories. In M. L. McLaughlin (Ed.), Communication Yearbook, 9, (pp. 339

  14. One-Dimensional Modelling of Marine Current Turbine Runaway Behaviour

    Directory of Open Access Journals (Sweden)

    Staffan Lundin

    2016-04-01

    Full Text Available If a turbine loses its electrical load, it will rotate freely and increase speed, eventually achieving that rotational speed which produces zero net torque. This is known as a runaway situation. Unlike many other types of turbine, a marine current turbine will typically overshoot the final runaway speed before slowing down and settling at the runaway speed. Since the hydrodynamic forces acting on the turbine are dependent on rotational speed and acceleration, turbine behaviour during runaway becomes important for load analyses during turbine design. In this article, we consider analytical and numerical models of marine current turbine runaway behaviour in one dimension. The analytical model is found not to capture the overshoot phenomenon, while still providing useful estimates of acceleration at the onset of runaway. The numerical model incorporates turbine wake build-up and predicts a rotational speed overshoot. The predictions of the models are compared against measurements of runaway of a marine current turbine. The models are also used to recreate previously-published results for a tidal turbine and applied to a wind turbine. It is found that both models provide reasonable estimates of maximum accelerations. The numerical model is found to capture the speed overshoot well.

  15. Comparison of analytical eddy current models using principal components analysis

    Science.gov (United States)

    Contant, S.; Luloff, M.; Morelli, J.; Krause, T. W.

    2017-02-01

    Monitoring the gap between the pressure tube (PT) and the calandria tube (CT) in CANDU® fuel channels is essential, as contact between the two tubes can lead to delayed hydride cracking of the pressure tube. Multifrequency transmit-receive eddy current non-destructive evaluation is used to determine this gap, as this method has different depths of penetration and variable sensitivity to noise, unlike single frequency eddy current non-destructive evaluation. An Analytical model based on the Dodd and Deeds solutions, and a second model that accounts for normal and lossy self-inductances, and a non-coaxial pickup coil, are examined for representing the response of an eddy current transmit-receive probe when considering factors that affect the gap response, such as pressure tube wall thickness and pressure tube resistivity. The multifrequency model data was analyzed using principal components analysis (PCA), a statistical method used to reduce the data set into a data set of fewer variables. The results of the PCA of the analytical models were then compared to PCA performed on a previously obtained experimental data set. The models gave similar results under variable PT wall thickness conditions, but the non-coaxial coil model, which accounts for self-inductive losses, performed significantly better than the Dodd and Deeds model under variable resistivity conditions.

  16. Cognitive models applied to human effectiveness in national security environments (ergonomics of augmented cognition system design and application).

    Energy Technology Data Exchange (ETDEWEB)

    Ntuen, Celestine (North Carolina Agricultural and Technical State University, Greensboro, NC); Winchester, Woodrow III (North Carolina Agricultural and Technical State University, Greensboro, NC)

    2004-06-01

    In complex simulation systems where humans interact with computer-generated agents, information display and the interplay of virtual agents have become dominant media and modalities of interface design. This design strategy is reflected in augmented reality (AR), an environment where humans interact with computer-generated agents in real-time. AR systems can generate large amount of information, multiple solutions in less time, and perform far better in time-constrained problem solving. The capabilities of AR have been leveraged to augment cognition in human information processing. In this sort of augmented cognition (AC) work system, while technology has become the main source for information acquisition from the environment, the human sensory and memory capacities have failed to cope with the magnitude and scale of information they encounter. This situation generates opportunity for excessive cognitive workloads, a major factor in degraded human performance. From the human effectiveness point of view, research is needed to develop, model, and validate simulation tools that can measure the effectiveness of an AR technology used to support the amplification of human cognition. These tools will allow us to predict human performance for tasks executed under an AC tool construct. This paper presents an exploration of ergonomics issues relevant to AR and AC systems design. Additionally, proposed research to investigate those ergonomic issues is discussed.

  17. Modeling of Learners’ Interest in Blended Learning: Insights from Emotional Cognition

    Directory of Open Access Journals (Sweden)

    Chen Hai-Jian

    2016-01-01

    Full Text Available In blended learning, how to explore and evaluate the learner’s interest is very important. In this paper, we study on modeling of learners’ interest from the perspective of cognitive neuroscience. Emotional cognitive theory and brain cognitive process for situational learning interest were introduced. In addition, in order to solve the problem of quantitative assessment of interest, learner’s online operation behaviour was summarized through data mining methods, and the learners' interest regression model was built. Experimental results show that the accuracy of the model is more than 91% and it has good applicability in blended learning.

  18. Social learning theory and cognitive behavioral models of body dysmorphic disorder.

    Science.gov (United States)

    Neziroglu, Fugen; Khemlani-Patel, Sony; Veale, David

    2008-03-01

    Contemporary cognitive behavioral models of body dysmorphic disorder are reviewed, whereby the first by Neziroglu and colleagues emphasizes conditioning processes and relational frame theory and the latter by Veale emphasizes information processing. A brief review of the existing cognitive behavioral therapy research follows the presentation of the models. The majority of publications on BDD continue to deal with phenomenology and epidemiology, and much more research on cognitive behavioral treatment is needed. Treatment research should be geared towards testing elements of the models explicated in this article, and randomized controlled trials are greatly needed.

  19. Flavor changing neutral currents in a realistic composite technicolor model

    Science.gov (United States)

    Carone, Christopher D.; Hamilton, Rowan T.

    1993-03-01

    We consider the phenomenology of a composite technicolor model proposed recently by Georgi. Composite technicolor interactions produce four-quark operators in the low energy theory that contribute to flavor changing neutral current processes. While we expect operators of this type to be induced at the compositeness scale by the flavor-symmetry breaking effects of the preon mass matrices, the Georgi model also includes operators from higher scales that are not GIM-suppressed. Since these operators are potentially large, we study their impact on flavor changing neutral currents and CP violation in the neutral K, B, and D meson systems. Notably, we find that this model gives rise to a typical value for {ɛ‧}/{ɛ} that is much smaller than most standard model estimates.

  20. Current Concepts: Mouse Models of Sjögren's Syndrome

    Directory of Open Access Journals (Sweden)

    Tegan N. Lavoie

    2011-01-01

    Full Text Available Sjögren's syndrome (SjS is a complex chronic autoimmune disease of unknown etiology which primarily targets the exocrine glands, resulting in eventual loss of secretory function. The disease can present as either primary SjS or secondary SjS, the latter of which occurs concomitantly with another autoimmune disease such as rheumatoid arthritis, systemic lupus erythematosus, scleroderma, or primary biliary cirrhosis. Current advancements in therapeutic prevention and treatment for SjS are impeded by lack of understanding in the pathophysiological and clinical progression of the disease. Development of appropriate mouse models for both primary and secondary SjS is needed in order to advance knowledge of this disease. This paper details important features, advantages, and pitfalls of current animal models of SjS, including spontaneous, transgenic, knockout, immunization, and transplantation chimera mouse models, and emphasizes the need for a better model in representing the human SjS phenotype.

  1. Analogue Behavioral Modeling of Switched-Current Building Block Circuits

    Institute of Scientific and Technical Information of China (English)

    ZENG Xuan; WANG Wei; SHI Jianlei; TANG Pushan; D.ZHOU

    2001-01-01

    This paper proposes a behavioral modeling technique for the second-generation switched-current building block circuits. The proposed models are capable of capturing the non-ideal behavior of switched-current circuits, which includes the charge injection effects and device mismatch effects. As a result, system performance degradations due to the building block imperfections can be detected at the early design stage by fast behavioral simulations. To evaluate the accuracy of the proposed models, we developed a time-domain behavioral simulator. Experimental results have shown that compared with SPICE, the behavioral modeling error is less than 2.15%, while behavioral simulation speed up is 4 orders in time-domain.

  2. Animal models of frailty: current applications in clinical research.

    Science.gov (United States)

    Kane, Alice E; Hilmer, Sarah N; Mach, John; Mitchell, Sarah J; de Cabo, Rafael; Howlett, Susan E

    2016-01-01

    The ethical, logistical, and biological complications of working with an older population of people inherently limits clinical studies of frailty. The recent development of animal models of frailty, and tools for assessing frailty in animal models provides an invaluable opportunity for frailty research. This review summarizes currently published animal models of frailty including the interleukin-10 knock-out mouse, the mouse frailty phenotype assessment tool, and the mouse clinical frailty index. It discusses both current and potential roles of these models in research into mechanisms of frailty, interventions to prevent/delay frailty, and the effect of frailty on outcomes. Finally, this review discusses some of the challenges and opportunities of translating research findings from animals to humans.

  3. Numeral eddy current sensor modelling based on genetic neural network

    Institute of Scientific and Technical Information of China (English)

    Yu A-Long

    2008-01-01

    This paper presents a method used to the numeral eddy current sensor modelling based on the genetic neural network to settle its nonlinear problem. The principle and algorithms of genetic neural network are introduced. In this method, the nonlinear model parameters of the numeral eddy current sensor are optimized by genetic neural network (GNN) according to measurement data. So the method remains both the global searching ability of genetic algorithm and the good local searching ability of neural network. The nonlinear model has the advantages of strong robustness,on-line modelling and high precision.The maximum nonlinearity error can be reduced to 0.037% by using GNN.However, the maximum nonlinearity error is 0.075% using the least square method.

  4. Cognitive behavioral therapy to aid weight loss in obese patients: current perspectives

    Directory of Open Access Journals (Sweden)

    Castelnuovo G

    2017-06-01

    Full Text Available Gianluca Castelnuovo,1,2 Giada Pietrabissa,1,2 Gian Mauro Manzoni,1,3 Roberto Cattivelli,1,2 Alessandro Rossi,1 Margherita Novelli,1 Giorgia Varallo,1 Enrico Molinari1,2 1Psychology Research Laboratory, Istituto Auxologico Italiano IRCCS, San Giuseppe Hospital, Verbania, 2Department of Psychology, Catholic University of Milan, Milan, 3Faculty of Psychology, eCampus University, Novedrate, Italy Abstract: Obesity is a chronic condition associated with risk factors for many medical ­complications and comorbidities such as cardiovascular diseases, some types of cancer, osteoarthritis, hypertension, dyslipidemia, hypercholesterolemia, type-2 diabetes, obstructive sleep apnea syndrome, and different psychosocial issues and psychopathological disorders. Obesity is a highly complex, multifactorial disease: genetic, biological, psychological, behavioral, familial, social, cultural, and environmental factors can influence in different ways. Evidence-based strategies to improve weight loss, maintain a healthy weight, and reduce related comorbidities typically integrate different interventions: dietetic, nutritional, physical, behavioral, psychological, and if necessary, pharmacological and surgical ones. Such treatments are implemented in a multidisciplinary context with a clinical team composed of endocrinologists, nutritionists, dietitians, physiotherapists, psychiatrists, psychologists, and sometimes surgeons. Cognitive behavioral therapy (CBT is traditionally recognized as the best established treatment for binge eating disorder and the most preferred intervention for obesity, and could be considered as the first-line treatment among psychological approaches, especially in a long-term perspective; however, it does not necessarily produce a successful weight loss. Traditional CBT for weight loss and other protocols, such as enhanced CBT, enhanced focused CBT, behavioral weight loss treatment, therapeutic education, acceptance and commitment therapy

  5. Neurocognitive poetics: methods and models for investigating the neuronal and cognitive-affective bases of literature reception

    Science.gov (United States)

    Jacobs, Arthur M.

    2015-01-01

    A long tradition of research including classical rhetoric, esthetics and poetics theory, formalism and structuralism, as well as current perspectives in (neuro)cognitive poetics has investigated structural and functional aspects of literature reception. Despite a wealth of literature published in specialized journals like Poetics, however, still little is known about how the brain processes and creates literary and poetic texts. Still, such stimulus material might be suited better than other genres for demonstrating the complexities with which our brain constructs the world in and around us, because it unifies thought and language, music and imagery in a clear, manageable way, most often with play, pleasure, and emotion (Schrott and Jacobs, 2011). In this paper, I discuss methods and models for investigating the neuronal and cognitive-affective bases of literary reading together with pertinent results from studies on poetics, text processing, emotion, or neuroaesthetics, and outline current challenges and future perspectives. PMID:25932010

  6. Neurocognitive poetics: methods and models for investigating the neuronal and cognitive-affective bases of literature reception.

    Science.gov (United States)

    Jacobs, Arthur M

    2015-01-01

    A long tradition of research including classical rhetoric, esthetics and poetics theory, formalism and structuralism, as well as current perspectives in (neuro)cognitive poetics has investigated structural and functional aspects of literature reception. Despite a wealth of literature published in specialized journals like Poetics, however, still little is known about how the brain processes and creates literary and poetic texts. Still, such stimulus material might be suited better than other genres for demonstrating the complexities with which our brain constructs the world in and around us, because it unifies thought and language, music and imagery in a clear, manageable way, most often with play, pleasure, and emotion (Schrott and Jacobs, 2011). In this paper, I discuss methods and models for investigating the neuronal and cognitive-affective bases of literary reading together with pertinent results from studies on poetics, text processing, emotion, or neuroaesthetics, and outline current challenges and future perspectives.

  7. Negative Cognition, Depressed Mood, and Paranoia: A Longitudinal Pathway Analysis Using Structural Equation Modeling

    Science.gov (United States)

    Fowler, David; Hodgekins, Joanne; Garety, Philippa; Freeman, Daniel; Kuipers, Elizabeth; Dunn, Graham; Smith, Ben; Bebbington, Paul E.

    2012-01-01

    The role of negative cognition and effect in maintaining psychotic symptoms is increasingly recognized but has yet to be substantiated though longitudinal analysis. Based on an a priori theoretical model, we hypothesized that negative cognition and depressed mood play a direct causal role in maintaining paranoia in people with psychosis and that the effect of mood is mediated by negative cognition. We used data from the 301 patients in the Prevention of Relapse in Psychosis Trial of cognitive behavior therapy. They were recruited from consecutive Community Mental Health Team clients presenting with a recent relapse of psychosis. The teams were located in inner and outer London and the rural county of Norfolk, England. The study followed a longitudinal cohort design, with initial measures repeated at 3 and 12 months. Structural equation modeling was used to investigate the direction of effect between negative cognition, depressed mood, and paranoia. Overall fit was ambiguous in some analyses and confounding by unidentified variables cannot be ruled out. Nevertheless, the most plausible models were those incorporating pathways from negative cognition and depressed mood to paranoid symptoms: There was no evidence whatsoever for pathways in the reverse direction. The link between depressed mood and paranoia appeared to be mediated by negative cognition. Our hypotheses were thus corroborated. This study provides evidence for the role of negative cognition in the maintenance of paranoia, a role of central relevance, both to the design of psychological interventions and to the conceptualizations of psychosis. PMID:21474550

  8. A turbidity current model for real world applications

    Science.gov (United States)

    Macías, Jorge; Castro, Manuel J.; Morales, Tomás

    2016-04-01

    Traditional turbidity current models suffer from several drawbacks. Among them not preserving freshwater mass, a missing pressure term, or not including terms related to deposition, erosion and entrainment in the momentum equation. In Morales et al.(2009) a new turbidity current model was proposed trying to overcome all these drawbacks. This model takes into account the interaction between the turbidity current and the bottom, considering deposition and erosion effects as well as solid bedload transport of particles at the bed due to the current. Moreover, this model includes the effects of the deposition, erosion and water entrainment into the momentum equation,commonly neglected in this type of models and, finally, in the absence of water entrainment, freshwater mass in the turbidity current is preserved. Despite these improvements, the numerical results obtained by this model when applied to real river systems were not satisfactory due to the simple form of the friction term that was considered. In the present work we propose a different parameterization of this term, where bottom and interface fluid frictions are separately parameterized with more complex expressions. Moreover, the discretization of the deposition/erosion terms is now performed semi-implicitly which guarantees the positivity of the volumetric concentration of sediments in suspension and in the erodible sediment layer at the bed. The numerical simulations obtained with this new turbidity current model (component of HySEA numerical computing platform) greatly improve previous numerical results for simplified geometries as well as for real river systems. Acknowledgements: This research has been partially supported by the Junta de Andalucía research project TESELA (P11-RNM7069) and the Spanish Government Research project DAIFLUID (MTM2012-38383-C02-01) and Universidad de Málaga, Campus de Excelencia Andalucía TECH. References: T. Morales, M. Castro, C. Parés, and E. Fernández-Nieto (2009). On

  9. Generalized Linear Models of home activity for automatic detection of mild cognitive impairment in older adults.

    Science.gov (United States)

    Akl, Ahmad; Snoek, Jasper; Mihailidis, Alex

    2014-01-01

    With a globally aging population, the burden of care of cognitively impaired older adults is becoming increasingly concerning. Instances of Alzheimer's disease and other forms of dementia are becoming ever more frequent. Earlier detection of cognitive impairment offers significant benefits, but remains difficult to do in practice. In this paper, we develop statistical models of the behavior of older adults within their homes using sensor data in order to detect the early onset of cognitive decline. Specifically, we use inhomogenous Poisson processes to model the presence of subjects within different rooms throughout the day in the home using unobtrusive sensing technologies. We compare the distributions learned from cognitively intact and impaired subjects using information theoretic tools and observe statistical differences between the two populations which we believe can be used to help detect the onset of cognitive decline.

  10. Predicting recovery of cognitive function soon after stroke: differential modeling of logarithmic and linear regression.

    Science.gov (United States)

    Suzuki, Makoto; Sugimura, Yuko; Yamada, Sumio; Omori, Yoshitsugu; Miyamoto, Masaaki; Yamamoto, Jun-ichi

    2013-01-01

    Cognitive disorders in the acute stage of stroke are common and are important independent predictors of adverse outcome in the long term. Despite the impact of cognitive disorders on both patients and their families, it is still difficult to predict the extent or duration of cognitive impairments. The objective of the present study was, therefore, to provide data on predicting the recovery of cognitive function soon after stroke by differential modeling with logarithmic and linear regression. This study included two rounds of data collection comprising 57 stroke patients enrolled in the first round for the purpose of identifying the time course of cognitive recovery in the early-phase group data, and 43 stroke patients in the second round for the purpose of ensuring that the correlation of the early-phase group data applied to the prediction of each individual's degree of cognitive recovery. In the first round, Mini-Mental State Examination (MMSE) scores were assessed 3 times during hospitalization, and the scores were regressed on the logarithm and linear of time. In the second round, calculations of MMSE scores were made for the first two scoring times after admission to tailor the structures of logarithmic and linear regression formulae to fit an individual's degree of functional recovery. The time course of early-phase recovery for cognitive functions resembled both logarithmic and linear functions. However, MMSE scores sampled at two baseline points based on logarithmic regression modeling could estimate prediction of cognitive recovery more accurately than could linear regression modeling (logarithmic modeling, R(2) = 0.676, Plinear regression modeling, R(2) = 0.598, P<0.0001). Logarithmic modeling based on MMSE scores could accurately predict the recovery of cognitive function soon after the occurrence of stroke. This logarithmic modeling with mathematical procedures is simple enough to be adopted in daily clinical practice.

  11. Predicting recovery of cognitive function soon after stroke: differential modeling of logarithmic and linear regression.

    Directory of Open Access Journals (Sweden)

    Makoto Suzuki

    Full Text Available Cognitive disorders in the acute stage of stroke are common and are important independent predictors of adverse outcome in the long term. Despite the impact of cognitive disorders on both patients and their families, it is still difficult to predict the extent or duration of cognitive impairments. The objective of the present study was, therefore, to provide data on predicting the recovery of cognitive function soon after stroke by differential modeling with logarithmic and linear regression. This study included two rounds of data collection comprising 57 stroke patients enrolled in the first round for the purpose of identifying the time course of cognitive recovery in the early-phase group data, and 43 stroke patients in the second round for the purpose of ensuring that the correlation of the early-phase group data applied to the prediction of each individual's degree of cognitive recovery. In the first round, Mini-Mental State Examination (MMSE scores were assessed 3 times during hospitalization, and the scores were regressed on the logarithm and linear of time. In the second round, calculations of MMSE scores were made for the first two scoring times after admission to tailor the structures of logarithmic and linear regression formulae to fit an individual's degree of functional recovery. The time course of early-phase recovery for cognitive functions resembled both logarithmic and linear functions. However, MMSE scores sampled at two baseline points based on logarithmic regression modeling could estimate prediction of cognitive recovery more accurately than could linear regression modeling (logarithmic modeling, R(2 = 0.676, P<0.0001; linear regression modeling, R(2 = 0.598, P<0.0001. Logarithmic modeling based on MMSE scores could accurately predict the recovery of cognitive function soon after the occurrence of stroke. This logarithmic modeling with mathematical procedures is simple enough to be adopted in daily clinical practice.

  12. Corticonic models of brain mechanisms underlying cognition and intelligence

    Science.gov (United States)

    Farhat, Nabil H.

    The concern of this review is brain theory or more specifically, in its first part, a model of the cerebral cortex and the way it: (a) interacts with subcortical regions like the thalamus and the hippocampus to provide higher-level-brain functions that underlie cognition and intelligence, (b) handles and represents dynamical sensory patterns imposed by a constantly changing environment, (c) copes with the enormous number of such patterns encountered in a lifetime by means of dynamic memory that offers an immense number of stimulus-specific attractors for input patterns (stimuli) to select from, (d) selects an attractor through a process of “conjugation” of the input pattern with the dynamics of the thalamo-cortical loop, (e) distinguishes between redundant (structured) and non-redundant (random) inputs that are void of information, (f) can do categorical perception when there is access to vast associative memory laid out in the association cortex with the help of the hippocampus, and (g) makes use of “computation” at the edge of chaos and information driven annealing to achieve all this. Other features and implications of the concepts presented for the design of computational algorithms and machines with brain-like intelligence are also discussed. The material and results presented suggest, that a Parametrically Coupled Logistic Map network (PCLMN) is a minimal model of the thalamo-cortical complex and that marrying such a network to a suitable associative memory with re-entry or feedback forms a useful, albeit, abstract model of a cortical module of the brain that could facilitate building a simple artificial brain. In the second part of the review, the results of numerical simulations and drawn conclusions in the first part are linked to the most directly relevant works and views of other workers. What emerges is a picture of brain dynamics on the mesoscopic and macroscopic scales that gives a glimpse of the nature of the long sought after brain code

  13. Modeling and strain gauging of eddy current repulsion deicing systems

    Science.gov (United States)

    Smith, Samuel O.

    1993-01-01

    Work described in this paper confirms and extends work done by Zumwalt, et al., on a variety of in-flight deicing systems that use eddy current repulsion for repelling ice. Two such systems are known as electro-impulse deicing (EIDI) and the eddy current repulsion deicing strip (EDS). Mathematical models for these systems are discussed for their capabilities and limitations. The author duplicates a particular model of the EDS. Theoretical voltage, current, and force results are compared directly to experimental results. Dynamic strain measurements results are presented for the EDS system. Dynamic strain measurements near EDS or EIDI coils are complicated by the high magnetic fields in the vicinity of the coils. High magnetic fields induce false voltage signals out of the gages.

  14. Current fluctuations in a two dimensional model of heat conduction

    Science.gov (United States)

    Pérez-Espigares, Carlos; Garrido, Pedro L.; Hurtado, Pablo I.

    2011-03-01

    In this work we study numerically and analytically current fluctuations in the two-dimensional Kipnis-Marchioro-Presutti (KMP) model of heat conduction. For that purpose, we use a recently introduced algorithm which allows the direct evaluation of large deviations functions. We compare our results with predictions based on the Hydrodynamic Fluctuation Theory (HFT) of Bertini and coworkers, finding very good agreement in a wide interval of current fluctuations. We also verify the existence of a well-defined temperature profile associated to a given current fluctuation which depends exclusively on the magnitude of the current vector, not on its orientation. This confirms the recently introduced Isometric Fluctuation Relation (IFR), which results from the time-reversibility of the dynamics, and includes as a particular instance the Gallavotti-Cohen fluctuation theorem in this context but adds a completely new perspective on the high level of symmetry imposed by timereversibility on the statistics of nonequilibrium fluctuations.

  15. Current Models and Innovative Strategies in Management Education in China.

    Science.gov (United States)

    Wang, Zhong-Ming

    1999-01-01

    Current models of management education in China include national training, on-the-job technical training, and the national master's of business administration supervisory committee. Effective strategies being used include teamwork, process skills, action learning, cross-cultural management learning, and competency-based management development. (SK)

  16. Hypersonic Vehicle Tracking Based on Improved Current Statistical Model

    Directory of Open Access Journals (Sweden)

    He Guangjun

    2013-11-01

    Full Text Available A new method of tracking the near space hypersonic vehicle is put forward. According to hypersonic vehicles’ characteristics, we improved current statistical model through online identification of the maneuvering frequency. A Monte Carlo simulation is used to analyze the performance of the method. The results show that the improved method exhibits very good tracking performance in comparison with the old method.

  17. Gompertz kinetics model of fast chemical neurotransmission currents.

    Science.gov (United States)

    Easton, Dexter M

    2005-10-01

    At a chemical synapse, transmitter molecules ejected from presynaptic terminal(s) bind reversibly with postsynaptic receptors and trigger an increase in channel conductance to specific ions. This paper describes a simple but accurate predictive model for the time course of the synaptic conductance transient, based on Gompertz kinetics. In the model, two simple exponential decay terms set the rates of development and decline of transmitter action. The first, r, triggering conductance activation, is surrogate for the decelerated rate of growth of conductance, G. The second, r', responsible for Y, deactivation of the conductance, is surrogate for the decelerated rate of decline of transmitter action. Therefore, the differential equation for the net conductance change, g, triggered by the transmitter is dg/dt=g(r-r'). The solution of that equation yields the product of G(t), representing activation, and Y(t), which defines the proportional decline (deactivation) of the current. The model fits, over their full-time course, published records of macroscopic ionic current associated with fast chemical transmission. The Gompertz model is a convenient and accurate method for routine analysis and comparison of records of synaptic current and putative transmitter time course. A Gompertz fit requiring only three independent rate constants plus initial current appears indistinguishable from a Markov fit using seven rate constants.

  18. [Neither Descartes nor Freud? current pain models in psychosomatic medicine].

    Science.gov (United States)

    Egloff, N; Egle, U T; von Känel, R

    2008-05-14

    Models explaining chronic pain based on the mere presence or absence of peripheral somatic findings or which view pain of psychological origin when there is no somatic explanation, have their shortcomings. Current scientific knowledge calls for distinct pain concepts, which integrate neurobiological and neuropsychological aspects of pain processing.

  19. Understanding psychogenic nonepileptic seizures-Phenomenology, semiology and the Integrative Cognitive Model.

    Science.gov (United States)

    Reuber, Markus; Brown, Richard J

    2017-01-01

    Psychogenic Nonepileptic Seizures (PNES) are one of the commonest differential diagnoses of epilepsy. This paper provides a narrative review of what has been learnt in the last 25 years regarding the visible manifestations, physiological features, subjective experiences and interactional aspects of PNES. We then explore how current insights into PNES semiology and phenomenology map onto the Integrative Cognitive Model (ICM), a new account of these phenomena that unifies previous approaches within a single explanatory framework. We discuss to what extent recent psychological and neurophysiological research is consistent with the ICM and indicate how the more detailed analysis of physiological data, connectivity analyses of EEG and functional or structural MRI data may provide greater insights into the biopsychosocial underpinnings of a disabling and under-researched disorder. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  20. Toward a model of cognitive insight in first-episode psychosis: verbal memory and hippocampal structure.

    Science.gov (United States)

    Buchy, L; Czechowska, Y; Chochol, C; Malla, A; Joober, R; Pruessner, J; Lepage, M

    2010-09-01

    Our previous work has linked verbal learning and memory with cognitive insight, but not clinical insight, in individuals with a first-episode psychosis (FEP). The current study reassessed the neurocognitive basis of cognitive and clinical insight and explored their neural basis in 61 FEP patients. Cognitive insight was measured with the Beck Cognitive Insight Scale (BCIS) and clinical insight with the Scale to assess Unawareness of Mental Disorder (SUMD). Global measures for 7 domains of cognition were examined. Hippocampi were manually segmented in to 3 parts: the body, head, and tail. Verbal learning and memory significantly correlated with the BCIS composite index. Composite index scores were significantly associated with total left hippocampal (HC) volume; partial correlations, however, revealed that this relationship was attributable largely to verbal memory performance. The BCIS self-certainty subscale significantly and inversely correlated with bilateral HC volumes, and these associations were independent of verbal learning and memory performance. The BCIS self-reflectiveness subscale significantly correlated with verbal learning and memory but not with HC volume. No significant correlations emerged between the SUMD and verbal memory or HC volume. These results strengthen our previous assertion that in individuals with an FEP cognitive insight may rely on memory whereby current experiences are appraised based on previous ones. The HC may be a viable location among others for the brain system that underlies aspects of cognitive insight in individuals with an FEP.

  1. The relationship of current depressive symptoms and past depression with cognitive impairment and instrumental activities of daily living in an elderly population: the Sydney Memory and Ageing Study.

    Science.gov (United States)

    Reppermund, S; Brodaty, H; Crawford, J D; Kochan, N A; Slavin, M J; Trollor, J N; Draper, B; Sachdev, P S

    2011-12-01

    Depressive symptoms are common in the elderly and they have been associated with cognitive and functional impairment. However, relatively less is known about the relationship of a lifetime history of depression to cognitive impairment and functional status. The aim of this cross-sectional study was to assess whether current depressive symptoms and past depression are associated with cognitive or functional impairment in a community-based sample representative of east Sydney, Australia. We also examined whether there was an interaction between current and past depression in their effects on cognitive performance. Eight hundred non-demented aged participants received a neuropsychological assessment, a past psychiatric history interview and the 15-item Geriatric Depression Scale. The Bayer-Activities of Daily Living scale was completed by an informant to determine functional ability. Clinically relevant depressive symptoms were present in 6.1% of the sample and 16.6% reported a history of depression. Participants with current depression had significantly higher levels of psychological distress and anxiety, and lower life satisfaction and performed worse on memory and executive function compared to participants without current depression. After controlling for anxiety the effect on executive function was no longer significant while the effect on memory remained significant. A history of depression was associated with worse executive function, higher levels of psychological distress and anxiety, and lower life satisfaction. After controlling for psychological distress the effect of past depression on executive function was no longer significant. There were no significant interactions between current and past depression in their effects on cognitive performance. There were no differences between participants with or without current depression and with or without past depression on functional abilities. These results support the view that current and past depressive

  2. Analytical Modeling for the Grating Eddy Current Displacement Sensors

    Directory of Open Access Journals (Sweden)

    Lv Chunfeng

    2015-02-01

    Full Text Available As a new type of displacement sensor, grating eddy current displacement sensor (GECDS combines traditional eddy current sensors and grating structure in one. The GECDS performs a wide range displacement measurement without precision reduction. This paper proposes an analytical modeling approach for the GECDS. The solution model is established in the Cartesian coordinate system, and the solving domain is limited to finite extents by using the truncated region eigenfunction expansion method. Based on the second order vector potential, expressions for the electromagnetic field as well as coil impedance related to the displacement can be expressed in closed-form. Theoretical results are then confirmed by experiments, which prove the suitability and effectiveness of the analytical modeling approach.

  3. Extending the Scope of the Acculturation/Pidginization Model to Include Cognition.

    Science.gov (United States)

    Schumann, John H.

    1990-01-01

    Examines five cognitive models for second-language acquisition (SLA) and assesses how each might account for the Pidginized interlanguage found in the early stages of second-language acquisition. (23 references) (JL)

  4. Teachers’ individual action theories about competence-based education: the value of the cognitive apprenticeship model

    OpenAIRE

    2009-01-01

    Seezink, A., Poell, R. F., & Kirschner, P. A. (2009). Teachers' individual action theories about competence-based education: The value of the cognitive apprenticeship model. Journal of Vocational Education & Training, 61, 203-215.

  5. Digital terrain model generalization incorporating scale, semantic and cognitive constraints

    Science.gov (United States)

    Partsinevelos, Panagiotis; Papadogiorgaki, Maria

    2014-05-01

    Cartographic generalization is a well-known process accommodating spatial data compression, visualization and comprehension under various scales. In the last few years, there are several international attempts to construct tangible GIS systems, forming real 3D surfaces using a vast number of mechanical parts along a matrix formation (i.e., bars, pistons, vacuums). Usually, moving bars upon a structured grid push a stretching membrane resulting in a smooth visualization for a given surface. Most of these attempts suffer either in their cost, accuracy, resolution and/or speed. Under this perspective, the present study proposes a surface generalization process that incorporates intrinsic constrains of tangible GIS systems including robotic-motor movement and surface stretching limitations. The main objective is to provide optimized visualizations of 3D digital terrain models with minimum loss of information. That is, to minimize the number of pixels in a raster dataset used to define a DTM, while reserving the surface information. This neighborhood type of pixel relations adheres to the basics of Self Organizing Map (SOM) artificial neural networks, which are often used for information abstraction since they are indicative of intrinsic statistical features contained in the input patterns and provide concise and characteristic representations. Nevertheless, SOM remains more like a black box procedure not capable to cope with possible particularities and semantics of the application at hand. E.g. for coastal monitoring applications, the near - coast areas, surrounding mountains and lakes are more important than other features and generalization should be "biased"-stratified to fulfill this requirement. Moreover, according to the application objectives, we extend the SOM algorithm to incorporate special types of information generalization by differentiating the underlying strategy based on topologic information of the objects included in the application. The final

  6. Numerical Model for Conduction-Cooled Current Lead Heat Loads

    CERN Document Server

    White, M J; Brueck, H D; 10.1063/1.4706965

    2012-01-01

    Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world, however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. The XFEL (X-Ray Free Electron Laser) magnets are operated at 2 K, which makes vapor-cooled current leads impractical due to the sub-atmospheric bath pressure. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal inte...

  7. The role of the dopamine D1 receptor in social cognition: studies using a novel genetic rat model­

    Science.gov (United States)

    VandenBroeke, Marie; Youn, Jiun; Ellenbroek, Arabella K.; Karel, Peter; Shan, Ling; van Boxtel, Ruben; Ooms, Sharon; Balemans, Monique; Langedijk, Jacqueline; Muller, Mareike; Vriend, Gert; Cools, Alexander R.; Cuppen, Edwin; Ellenbroek, Bart A.

    2016-01-01

    ABSTRACT Social cognition is an endophenotype that is impaired in schizophrenia and several other (comorbid) psychiatric disorders. One of the modulators of social cognition is dopamine, but its role is not clear. The effects of dopamine are mediated through dopamine receptors, including the dopamine D1 receptor (Drd1). Because current Drd1 receptor agonists are not Drd1 selective, pharmacological tools are not sufficient to delineate the role of the Drd1. Here, we describe a novel rat model with a genetic mutation in Drd1 in which we measured basic behavioural phenotypes and social cognition. The I116S mutation was predicted to render the receptor less stable. In line with this computational prediction, this Drd1 mutation led to a decreased transmembrane insertion of Drd1, whereas Drd1 expression, as measured by Drd1 mRNA levels, remained unaffected. Owing to decreased transmembrane Drd1 insertion, the mutant rats displayed normal basic motoric and neurological parameters, as well as locomotor activity and anxiety-like behaviour. However, measures of social cognition like social interaction, scent marking, pup ultrasonic vocalizations and sociability, were strongly reduced in the mutant rats. This profile of the Drd1 mutant rat offers the field of neuroscience a novel genetic rat model to study a series of psychiatric disorders including schizophrenia, autism, depression, bipolar disorder and drug addiction. PMID:27483345

  8. Modelling Human Cognitive Development with Explanation-Based Learning in Soar

    Science.gov (United States)

    1990-02-02

    of Pittsburgh BEST AVAILABLE COPY AXpprovedI for public rleaw4: distributimi unintilieu. 90 Z:L 0 Q3 7 MODELLING HUMAN COGNITIVE DEVELOPMENT WITH...NO. No. ACCESSION NO N/A N/A N/A N/A I I TITLE (*XcA* SecsaiY O7fiCatl) Modelling human cognitive development with explanation-bsed learning in Soar...P I cognitive development Soar I I I j~n--qq~ learning 19. ABSTRACT (Continue on reverse if noeessary and identy by block -number) SEE REVERSE SIDE 20

  9. Cognitive/emotional models for human behavior representation in 3D avatar simulations

    Science.gov (United States)

    Peterson, James K.

    2004-08-01

    Simplified models of human cognition and emotional response are presented which are based on models of auditory/ visual polymodal fusion. At the core of these models is a computational model of Area 37 of the temporal cortex which is based on new isocortex models presented recently by Grossberg. These models are trained using carefully chosen auditory (musical sequences), visual (paintings) and higher level abstract (meta level) data obtained from studies of how optimization strategies are chosen in response to outside managerial inputs. The software modules developed are then used as inputs to character generation codes in standard 3D virtual world simulations. The auditory and visual training data also enable the development of simple music and painting composition generators which significantly enhance one's ability to validate the cognitive model. The cognitive models are handled as interacting software agents implemented as CORBA objects to allow the use of multiple language coding choices (C++, Java, Python etc) and efficient use of legacy code.

  10. Stakeholder approach, Stakeholders mental model: A visualization test with cognitive mapping technique

    Directory of Open Access Journals (Sweden)

    Garoui Nassreddine

    2012-04-01

    Full Text Available The idea of this paper is to determine the mental models of actors in the firm with respect to the stakeholder approach of corporate governance. The use of the cognitive map to view these diagrams to show the ways of thinking and conceptualization of the stakeholder approach. The paper takes a corporate governance perspective, discusses stakeholder model. It takes also a cognitive mapping technique.

  11. The Past, Present, and Future of Computational Models of Cognitive Development

    Science.gov (United States)

    Schlesinger, Matthew; McMurray, Bob

    2012-01-01

    Does modeling matter? We address this question by providing a broad survey of the computational models of cognitive development that have been proposed and studied over the last three decades. We begin by noting the advantages and limitations of computational models. We then describe four key dimensions across which models of development can be…

  12. The Past, Present, and Future of Computational Models of Cognitive Development

    Science.gov (United States)

    Schlesinger, Matthew; McMurray, Bob

    2012-01-01

    Does modeling matter? We address this question by providing a broad survey of the computational models of cognitive development that have been proposed and studied over the last three decades. We begin by noting the advantages and limitations of computational models. We then describe four key dimensions across which models of development can be…

  13. A Comparative Structural Equation Modeling Investigation of the Relationships among Teaching, Cognitive and Social Presence

    Science.gov (United States)

    Kozan, Kadir

    2016-01-01

    The present study investigated the relationships among teaching, cognitive, and social presence through several structural equation models to see which model would better fit the data. To this end, the present study employed and compared several different structural equation models because different models could fit the data equally well. Among…

  14. Retrofitting Non-Cognitive-Diagnostic Reading Assessment under the Generalized DINA Model Framework

    Science.gov (United States)

    Chen, Huilin; Chen, Jinsong

    2016-01-01

    Cognitive diagnosis models (CDMs) are psychometric models developed mainly to assess examinees' specific strengths and weaknesses in a set of skills or attributes within a domain. By adopting the Generalized-DINA model framework, the recently developed general modeling framework, we attempted to retrofit the PISA reading assessments, a…

  15. The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence from Word Segmentation

    Science.gov (United States)

    Phillips, Lawrence; Pearl, Lisa

    2015-01-01

    The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's "cognitive plausibility." We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition…

  16. The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence from Word Segmentation

    Science.gov (United States)

    Phillips, Lawrence; Pearl, Lisa

    2015-01-01

    The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's "cognitive plausibility." We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition…

  17. Efficacy of cognitive rehabilitation therapies for mild cognitive impairment (MCI) in older adults: working toward a theoretical model and evidence-based interventions.

    Science.gov (United States)

    Huckans, Marilyn; Hutson, Lee; Twamley, Elizabeth; Jak, Amy; Kaye, Jeffrey; Storzbach, Daniel

    2013-03-01

    To evaluate the efficacy of cognitive rehabilitation therapies (CRTs) for mild cognitive impairment (MCI). Our review revealed a need for evidence-based treatments for MCI and a lack of a theoretical rehabilitation model to guide the development and evaluation of these interventions. We have thus proposed a theoretical rehabilitation model of MCI that yields key intervention targets-cognitive compromise, functional compromise, neuropsychiatric symptoms, and modifiable risk and protective factors known to be associated with MCI and dementia. Our model additionally defines specific cognitive rehabilitation approaches that may directly or indirectly target key outcomes-restorative cognitive training, compensatory cognitive training, lifestyle interventions, and psychotherapeutic techniques. Fourteen randomized controlled trials met inclusion criteria and were reviewed. Studies markedly varied in terms of intervention approaches and selected outcome measures and were frequently hampered by design limitations. The bulk of the evidence suggested that CRTs can change targeted behaviors in individuals with MCI and that CRTs are associated with improvements in objective cognitive performance, but the pattern of effects on specific cognitive domains was inconsistent across studies. Other important outcomes (i.e., daily functioning, quality of life, neuropsychiatric symptom severity) were infrequently assessed across studies. Few studies evaluated long-term outcomes or the impact of CRTs on conversion rates from MCI to dementia or normal cognition. Overall, results from trials are promising but inconclusive. Additional well-designed and adequately powered trials are warranted and required before CRTs for MCI can be considered evidence-based.

  18. A DYNAMIC-SYSTEMS MODEL OF COGNITIVE AND LANGUAGE GROWTH

    NARCIS (Netherlands)

    VANGEERT, P

    In the first part of the article, a conceptual framework is sketched to define cognitive growth, including language growth, as a process of growth under limited resources. Important concepts are the process, level, and rate of growth; minimal structural growth level; carrying capacity and unutilized

  19. Formal modeling and analysis of cognitive agent behavior

    NARCIS (Netherlands)

    Sharpanskykh, Alexei; Treur, Jan

    2007-01-01

    From an external perspective, cognitive agent behavior can be described by specifying (temporal) correlations of a certain complexity between stimuli (input states) and (re)actions (output states) of the agent. From an internal perspective the agent’s dynamics can be characterized by direct (causa

  20. Empirical Network Model of Human Higher Cognitive Brain Functions

    Science.gov (United States)

    1990-03-31

    EEG potentials during cognition. Science. 1981. 213: 918-921- and mental activity in juvenile delinquents. Electroenceph. Gevns, .A.S.. Schafier. R.F...their latency and topography depend on the moda - litv. intensity, and other physical properties of the stimulus. The P100 and NIO0 peaks are also

  1. Modeling Cognitive Strategies during Complex Task Performing Process

    Science.gov (United States)

    Mazman, Sacide Guzin; Altun, Arif

    2012-01-01

    The purpose of this study is to examine individuals' computer based complex task performing processes and strategies in order to determine the reasons of failure by cognitive task analysis method and cued retrospective think aloud with eye movement data. Study group was five senior students from Computer Education and Instructional Technologies…

  2. DOORS English--The Cognitive Basis of Rhetorical Models.

    Science.gov (United States)

    Taylor, Karl K.

    1979-01-01

    The Development of Operational Reasoning Skills (DOORS) program at Illinois Central College is an interdisciplinary experiment that guides students from concrete to formal operational levels of thought to ensure that they understand the concepts and cognitive skills undergirding the rhetorical modes. (RL)

  3. How does rumination impact cognition? A first mechanistic model.

    NARCIS (Netherlands)

    van Vugt, Marieke; van der Velde, Maarten; van Vugt, Marieke; Banks, Adrian P; Kennedy, William G

    2017-01-01

    Rumination is a process of uncontrolled, narrowly-foused neg- ative thinking that is often self-referential, and that is a hall- mark of depression. Despite its importance, little is known about its cognitive mechanisms. Rumination can be thought of as a specific, constrained form of mind-wandering.

  4. Learning online community citizenship behavior: a socio-cognitive model.

    Science.gov (United States)

    Joe, Sheng-Wuu; Lin, Chieh-Peng

    2008-06-01

    This study postulates personal and environmental factors as key drivers of online community citizenship behavior (OCCB). OCCB reveals that the individual chooses to perform a behavior that is beneficial to others. Empirical results confirm the applicability of social cognitive theory (SCT) in online communities.

  5. Architectural considerations for modeling cognitive-emotional decision making

    NARCIS (Netherlands)

    Lotens, W.A.; Cain, B.

    2013-01-01

    There are numerous conceptual similarities between affective and rational decision making functions despite the differences between the emotional and cognitive systems. Aspects of emotion may be considered as a concurrent stream of information processing that is coupled with explicit, rational infor

  6. Does attainment of Piaget's formal operational level of cognitive development predict student understanding of scientific models?

    Science.gov (United States)

    Lahti, Richard Dennis, II

    Knowledge of scientific models and their uses is a concept that has become a key benchmark in many of the science standards of the past 30 years, including the proposed Next Generation Science Standards. Knowledge of models is linked to other important nature of science concepts such as theory change which are also rising in prominence in newer standards. Effective methods of instruction will need to be developed to enable students to achieve these standards. The literature reveals an inconsistent history of success with modeling education. These same studies point to a possible cognitive development component which might explain why some students succeeded and others failed. An environmental science course, rich in modeling experiences, was used to test both the extent to which knowledge of models and modeling could be improved over the course of one semester, and more importantly, to identify if cognitive ability was related to this improvement. In addition, nature of science knowledge, particularly related to theories and theory change, was also examined. Pretest and posttest results on modeling (SUMS) and nature of science (SUSSI), as well as data from the modeling activities themselves, was collected. Cognitive ability was measured (CTSR) as a covariate. Students' gain in six of seven categories of modeling knowledge was at least medium (Cohen's d >.5) and moderately correlated to CTSR for two of seven categories. Nature of science gains were smaller, although more strongly correlated with CTSR. Student success at creating a model was related to CTSR, significantly in three of five sub-categories. These results suggest that explicit, reflective experience with models can increase student knowledge of models and modeling (although higher cognitive ability students may have more success), but successfully creating models may depend more heavily on cognitive ability. This finding in particular has implications in the grade placement of modeling standards and

  7. A fluid mechanical model for current-generating-feeding jellyfish

    Science.gov (United States)

    Peng, Jifeng; Dabiri, John

    2008-11-01

    Many jellyfish species, e.g. moon jellyfish Aurelia aurita, use body motion to generate fluid currents which carry their prey to the vicinity of their capture appendages. In this study, a model was developed to understand the fluid mechanics for this current-generating-feeding mode of jellyfish. The flow generated by free-swimming Aurelia aurita was measured using digital particle image velocimetry. The dynamics of prey (e.g., brine shrimp Artemia) in the flow field were described by a modified Maxey-Riley equation which takes into consideration the inertia of prey and the escape forces, which prey exert in the presence of predator. A Lagrangian analysis was used to identify the region of the flow in which prey can be captured by the jellyfish and the clearance rate was quantified. The study provides a new methodology to study biological current-generating-feeding and the transport and mixing of particles in fluid flow in general.

  8. 3-dimensional current collection model. [of Tethered Satellite System 1

    Science.gov (United States)

    Hwang, Kai-Shen; Shiah, A.; Wu, S. T.; Stone, N.

    1992-01-01

    A three-dimensional, time dependent current collection model of a satellite has been developed for the TSS-1 system. The system has been simulated particularly for the Research of Plasma Electrodynamics (ROPE) experiment. The Maxwellian distributed particles with the geomagnetic field effects are applied in this numerical simulation. The preliminary results indicate that a ring current is observed surrounding the satellite in the equatorial plane. This ring current is found between the plasma sheath and the satellite surface and is oscillating with a time scale of approximately 1 microsec. This is equivalent to the electron plasma frequency. An hour glass shape of electron distribution was observed when the viewing direction is perpendicular to the equatorial plane. This result is consistent with previous findings from Linson (1969) and Antoniades et al. (1990). Electrons that are absorbed by the satellite are limited from the background ionosphere as indicated by Parker and Murphy (1967).

  9. Textual analysis of Nahjolbalaqa letters based on Bloom’s Cognitive Model

    Directory of Open Access Journals (Sweden)

    Parviz Alavinia

    2012-08-01

    Full Text Available The dominion of Islamic world is replete with varied theological and spiritual masterpieces. One such outstanding work which has outlived its own time and the passage of time has not been able to undermine its beauty is Nahjolbalaqa (a road to eloquence. Nahjolbalaqa, the collection of Imam Ali’s (peace be upon him statements, consists of three different parts alternatively known as ‘Sermons’, ‘Letters’, and ‘Wisdom’. The main purpose of this exploratory study is the textual analysis of ‘letters’ of Nahjolbalaqa according to Bloom’s cognitive model. Based on Bloom’s taxonomy, there are six different cognitive levels commencing with the most concrete and gradually moving toward the more abstract end of the continuum. These levels are termed Knowledge, Comprehension, Application, Analysis, Synthesis, and Evaluation. In the current scrutiny, all the 79 ‘letters’ of Nahjolbalaqa, which amount to 255 titles if we consider their subcategories, have been analyzed according to Bloom’s model in an attempt to come up with a vivid elucidation of their characteristics. As the final analysis of the gained upshots revealed, the majority of ‘letters’ pored over were found to comply with the levels of evaluation and knowledge in Bloom’s model. Ultimately, it is hoped that the present study would prove helpful for commentators and all those who are in need of a deeper understanding of Nahjolbalaqa, particularly when it comes to finding out the corresponding level of abstraction for each individual ‘letter’.

  10. Putative cognitive enhancers in preclinical models related to schizophrenia: the search for an elusive target.

    Science.gov (United States)

    Barak, Segev; Weiner, Ina

    2011-08-01

    Several developments have converged to drive what may be called "the cognitive revolution" in drug discovery in schizophrenia (SCZ), including the emphasis on cognitive deficits as a core disabling aspect of SCZ, the increasing consensus that cognitive deficits are not treated satisfactorily by the available antipsychotic drugs (APDs), and the failure of animal models to predict drug efficacy for cognitive deficits in clinical trials. Consequently, in recent years, a paradigm shift has been encouraged in animal modeling, triggered by the NIMH sponsored Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative, and intended to promote the development and use of behavioral measures in animals that can generate valid (clinically relevant) measures of cognition and thus promote the identification of cognition enhancers for SCZ. Here, we provide a non-exhaustive survey of the effects of putative cognition enhancers (PCEs) representing 10 pharmacological targets as well as antipsychotic drugs (APDs), on SCZ-mimetic drugs (NMDA antagonists, muscarinic antagonist scopolamine and dopaminergic agonist amphetamine), in several tasks considered to measure cognitive processes/domains that are disrupted in SCZ (the five choice serial reaction time task, sustain attention task, working and/or recognition memory (delayed (non)matching to sample, delayed alternation task, radial arm maze, novel object recognition), reversal learning, attentional set shifting, latent inhibition and spatial learning and memory). We conclude that most of the available models have no capacity to distinguish between PCEs and APDs and that there is a need to establish models based on tasks whose perturbations lead to performance impairments that are resistant to APDs, and/or to accept APDs as a "weak gold standard". Several directions derived from the surveyed data are suggested.

  11. Dynamic mechanistic explanation: computational modeling of circadian rhythms as an exemplar for cognitive science.

    Science.gov (United States)

    Bechtel, William; Abrahamsen, Adele

    2010-09-01

    We consider computational modeling in two fields: chronobiology and cognitive science. In circadian rhythm models, variables generally correspond to properties of parts and operations of the responsible mechanism. A computational model of this complex mechanism is grounded in empirical discoveries and contributes a more refined understanding of the dynamics of its behavior. In cognitive science, on the other hand, computational modelers typically advance de novo proposals for mechanisms to account for behavior. They offer indirect evidence that a proposed mechanism is adequate to produce particular behavioral data, but typically there is no direct empirical evidence for the hypothesized parts and operations. Models in these two fields differ in the extent of their empirical grounding, but they share the goal of achieving dynamic mechanistic explanation. That is, they augment a proposed mechanistic explanation with a computational model that enables exploration of the mechanism's dynamics. Using exemplars from circadian rhythm research, we extract six specific contributions provided by computational models. We then examine cognitive science models to determine how well they make the same types of contributions. We suggest that the modeling approach used in circadian research may prove useful in cognitive science as researchers develop procedures for experimentally decomposing cognitive mechanisms into parts and operations and begin to understand their nonlinear interactions.

  12. Passive Target Tracking Based on Current Statistical Model

    Institute of Scientific and Technical Information of China (English)

    DENG Xiao-long; XIE Jian-ying; YANG Yu-pu

    2005-01-01

    Bearing-only passive tracking is regarded as a nonlinear hard tracking problem. There are still no completely good solutions to this problem until now. Based on current statistical model, the novel solution to this problem utilizing particle filter (PF) and the unscented Kalman filter (UKF) is proposed. The new solution adopts data fusion from two observers to increase the observability of passive tracking. It applies the residual resampling step to reduce the degeneracy of PF and it introduces the Markov Chain Monte Carlo methods (MCMC) to reduce the effect of the "sample impoverish". Based on current statistical model, the EKF, the UKF and particle filter with various proposal distributions are compared in the passive tracking experiments with two observers. The simulation results demonstrate the good performance of the proposed new filtering methods with the novel techniques.

  13. Energy current loss instability model on a computer

    Science.gov (United States)

    Edighoffer, John A.

    1995-04-01

    The computer program called Energy Stability in a Recirculating Accelerator (ESRA) Free Electron Laser (FEL) has been written to model bunches of particles in longitudinal phase space transversing a recirculating accelerator and the associated rf changes and aperture current losses. This energy-current loss instability was first seen by Los Alamos's FEL group in their energy recovery experiments. This code addresses these stability issues and determines the transport, noise, feedback and other parameters for which these FEL systems are stable or unstable. Two representative systems are modeled, one for the Novosibirisk high power FEL racetrack microtron for photochemical research, the other is the CEBAF proposed UV FEL system. Both of these systems are stable with prudent choices of parameters.

  14. Charge and Current in the Quantum Hall Matrix Model

    OpenAIRE

    2003-01-01

    We extend the quantum Hall matrix model to include couplings to external electric and magnetic fields. The associated current suffers from matrix ordering ambiguities even at the classical level. We calculate the linear response at low momenta -- this is unambigously defined. In particular, we obtain the correct fractional quantum Hall conductivity, and the expected density modulations in response to a weak and slowly varying magnetic field. These results show that the classical quantum Hall ...

  15. Error-preceding brain activity reflects (mal-)adaptive adjustments of cognitive control: a modeling study.

    Science.gov (United States)

    Steinhauser, Marco; Eichele, Heike; Juvodden, Hilde T; Huster, Rene J; Ullsperger, Markus; Eichele, Tom

    2012-01-01

    Errors in choice tasks are preceded by gradual changes in brain activity presumably related to fluctuations in cognitive control that promote the occurrence of errors. In the present paper, we use connectionist modeling to explore the hypothesis that these fluctuations reflect (mal-)adaptive adjustments of cognitive control. We considered ERP data from a study in which the probability of conflict in an Eriksen-flanker task was manipulated in sub-blocks of trials. Errors in these data were preceded by a gradual decline of N2 amplitude. After fitting a connectionist model of conflict adaptation to the data, we analyzed simulated N2 amplitude, simulated response times (RTs), and stimulus history preceding errors in the model, and found that the model produced the same pattern as obtained in the empirical data. Moreover, this pattern is not found in alternative models in which cognitive control varies randomly or in an oscillating manner. Our simulations suggest that the decline of N2 amplitude preceding errors reflects an increasing adaptation of cognitive control to specific task demands, which leads to an error when these task demands change. Taken together, these results provide evidence that error-preceding brain activity can reflect adaptive adjustments rather than unsystematic fluctuations of cognitive control, and therefore, that these errors are actually a consequence of the adaptiveness of human cognition.

  16. Using implicit association tests in age-heterogeneous samples: The importance of cognitive abilities and quad model processes.

    Science.gov (United States)

    Wrzus, Cornelia; Egloff, Boris; Riediger, Michaela

    2017-08-01

    Implicit association tests (IATs) are increasingly used to indirectly assess people's traits, attitudes, or other characteristics. In addition to measuring traits or attitudes, IAT scores also reflect differences in cognitive abilities because scores are based on reaction times (RTs) and errors. As cognitive abilities change with age, questions arise concerning the usage and interpretation of IATs for people of different age. To address these questions, the current study examined how cognitive abilities and cognitive processes (i.e., quad model parameters) contribute to IAT results in a large age-heterogeneous sample. Participants (N = 549; 51% female) in an age-stratified sample (range = 12-88 years) completed different IATs and 2 tasks to assess cognitive processing speed and verbal ability. From the IAT data, D2-scores were computed based on RTs, and quad process parameters (activation of associations, overcoming bias, detection, guessing) were estimated from individual error rates. Substantial IAT scores and quad processes except guessing varied with age. Quad processes AC and D predicted D2-scores of the content-specific IAT. Importantly, the effects of cognitive abilities and quad processes on IAT scores were not significantly moderated by participants' age. These findings suggest that IATs seem suitable for age-heterogeneous studies from adolescence to old age when IATs are constructed and analyzed appropriately, for example with D-scores and process parameters. We offer further insight into how D-scoring controls for method effects in IATs and what IAT scores capture in addition to implicit representations of characteristics. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. Modeling the heliospheric current sheet: Solar cycle variations

    Science.gov (United States)

    Riley, Pete; Linker, J. A.; Mikić, Z.

    2002-07-01

    In this report we employ an empirically driven, three-dimensional MHD model to explore the evolution of the heliospheric current sheet (HCS) during the course of the solar cycle. We compare our results with a simpler ``constant-speed'' approach for mapping the HCS outward into the solar wind to demonstrate that dynamic effects can substantially deform the HCS in the inner heliosphere (ballerina skirt,'' we discuss an interval approaching the maximum of solar cycle 23 (Carrington rotations 1960 and 1961) when the shape would be better described as ``conch shell''-like. We use Ulysses magnetic field measurements to support the model results.

  18. Pion electromagnetic current in a light-front model

    CERN Document Server

    Pacheco-Bicudo-Cabral de Melo, J; Frederico, T

    1999-01-01

    The electromagnetic form factor of the pion is calculated in a pseudoscalar field theoretical model which constituent quarks. We extract the form factor using the "+" component of the electromagnetic current in the light-cone formalism. For comparison, we also compute the form factor in the covariant framework and we obtain perfect agreement. It is shown that the pair terms do not contribute in this pseudoscalar model. This explains why a naive light-cone calculation, i.e., omitting pair terms from the onset, also yields the same results.

  19. Current state of genome-scale modeling in filamentous fungi

    DEFF Research Database (Denmark)

    Brandl, Julian; Andersen, Mikael Rørdam

    2015-01-01

    The group of filamentous fungi contains important species used in industrial biotechnology for acid, antibiotics and enzyme production. Their unique lifestyle turns these organisms into a valuable genetic reservoir of new natural products and biomass degrading enzymes that has not been used to full...... testing them in vivo. The increasing availability of high quality models and molecular biological tools for manipulating filamentous fungi renders the model-guided engineering of these fungal factories possible with comprehensive metabolic networks. A typical fungal model contains on average 1138 unique...... metabolic reactions and 1050 ORFs, making them a vast knowledge-base of fungal metabolism. In the present review we focus on the current state as well as potential future applications of genome-scale models in filamentous fungi....

  20. Persistent current in an almost staggered Harper model

    Science.gov (United States)

    Vasserman, A.; Berkovits, R.

    2015-08-01

    In this paper we study the persistent current (PC) of a staggered Harper model, close to the half-filling. The Harper model is different than other one dimensional disordered systems which are always localized, since it is a quasi-periodic system with correlated disorder resulting in the fact that it can be in the metallic regime. Nevertheless, the PC for a wide range of parameters of the Harper model does not show typical metallic behavior, although the system is in the metallic regime. This is a result of the nature of the central band states, which are a hybridization of Gaussian states localized in superlattice points. When the superlattice is not commensurate with the system length, the PC behaves as an insulator. Thus even in the metallic regime a typical finite Harper model may exhibit a PC expected from an insulator.

  1. A Longitudinal Operant Assessment of Cognitive and Behavioural Changes in the HdhQ111 Mouse Model of Huntington’s Disease

    Science.gov (United States)

    Dunnett, Stephen B.; Brooks, Simon P.

    2016-01-01

    Huntington’s disease (HD) is characterised by motor symptoms which are often preceded by cognitive and behavioural changes, that can significantly contribute to disease burden for people living with HD. Numerous knock-in mouse models of HD are currently available for scientific research. However, before their use, they must be behaviourally characterised to determine their suitability in recapitulating the symptoms of the human condition. Thus, we sought to longitudinally characterise the nature, severity and time course of cognitive and behavioural changes observed in HdhQ111 heterozygous knock-in mice.To determine changes in cognition and behaviour an extensive battery of operant tests including: fixed ratio, progressive ratio, the five choice serial reaction time task and the serial implicit learning task, were applied longitudinally to HdhQ111 and wild type mice. The operant test battery was conducted at 6, 12 and 18 months of age. Significant deficits were observed in HdhQ111 animals in comparison to wild type animals in all operant tests indicating altered cognition (attentional and executive function) and motivation. However, the cognitive and behavioural deficits observed were not shown to be progressive over time in the longitudinal testing paradigm that was utilised. The results therefore demonstrate that the HdhQ111 mouse model of HD reflects some features of the cognitive and behavioural changes shown in the human condition of HD. Although, the cognitive and behavioural deficits demonstrated were not shown to be progressive over time. PMID:27701442

  2. Modeling Electric Current Flow in 3D Fractured Media

    Science.gov (United States)

    Demirel, S.; Roubinet, D.; Irving, J.

    2014-12-01

    The study of fractured rocks is extremely important in a variety of research fields and applications such as hydrogeology, hydrocarbon extraction and long-term storage of toxic waste. As fractures are highly conductive structures in comparison to the surrounding rock, their presence can be either an advantage or a drawback. For hydrocarbon extraction, fractures allow for quick and easy access to the resource whereas for toxic waste storage their presence increases the risk of leakage and migration of pollutants. In both cases, the identification of fracture network characteristics is an essential step. Recently, we have developed an approach for modeling electric current flow in 2D fractured media. This approach is based on a discrete-dual-porosity model where fractures are represented explicitly, the matrix is coarsely discretized into blocks, and current flow exchange between the fractures and matrix is analytically evaluated at the fracture-scale and integrated at the block-scale [1]. Although this approach has shown much promise and has proven its efficiency for 2D simulations, its extension to 3D remains to be addressed. To this end, we assume that fractures can be represented as two-dimensional finite planes embedded in the surrounding matrix, and we express analytically the distribution of electric potential at the fracture scale. This fracture-scale expression takes into account the electric-current-flow exchange with the surrounding matrix and flow conservation is enforced at the fracture intersections. The fracture-matrix exchange is then integrated at the matrix-block scale where the electric current flow conservation at the block boundaries is formulated with a modified finite volume method. With the objective of providing a low-computational-cost modeling approach adapted to 3D simulations in fractured media, our model is (i) validated and compared to existing modeling approaches and, (ii) used to evaluate the impact of the presence of fractures on

  3. Homology Modeling a Fast Tool for Drug Discovery: Current Perspectives

    Science.gov (United States)

    Vyas, V. K.; Ukawala, R. D.; Ghate, M.; Chintha, C.

    2012-01-01

    Major goal of structural biology involve formation of protein-ligand complexes; in which the protein molecules act energetically in the course of binding. Therefore, perceptive of protein-ligand interaction will be very important for structure based drug design. Lack of knowledge of 3D structures has hindered efforts to understand the binding specificities of ligands with protein. With increasing in modeling software and the growing number of known protein structures, homology modeling is rapidly becoming the method of choice for obtaining 3D coordinates of proteins. Homology modeling is a representation of the similarity of environmental residues at topologically corresponding positions in the reference proteins. In the absence of experimental data, model building on the basis of a known 3D structure of a homologous protein is at present the only reliable method to obtain the structural information. Knowledge of the 3D structures of proteins provides invaluable insights into the molecular basis of their functions. The recent advances in homology modeling, particularly in detecting and aligning sequences with template structures, distant homologues, modeling of loops and side chains as well as detecting errors in a model contributed to consistent prediction of protein structure, which was not possible even several years ago. This review focused on the features and a role of homology modeling in predicting protein structure and described current developments in this field with victorious applications at the different stages of the drug design and discovery. PMID:23204616

  4. Study on Consumers’ Cognitive Behavior of New Products in Current Network Information Environment%网络信息环境下消费者对新产品认知行为研究

    Institute of Scientific and Technical Information of China (English)

    高洁; 杨巨峰; 李川

    2014-01-01

    From the macroscopic and microscopic aspects, this paper expounds the environmental factors influencing consumers’ cognitive behavior, and further from the perspective of psychology, analyzes the cognitive process of consumers, and connecting with the current development of information network, introduces the new SICAS mode for consumers’ cognitive behavior; based on being clear about the related factors of consumers’ cognitive behavior, designs the survey questionnaire of consumers’ cognitive behavior according to consumers’ cognitive model, and finds the cognitive changes of consumers through understanding consumers’ decision-making behavior in the process of using the new products;and puts forward some suggestions from the perspective of enterprise to promote the new products.%从宏观和微观两个方面阐述了影响消费者认知行为的环境因素,进而从心理学的角度分析了消费者的认知过程,并且结合当前信息网络的发展介绍了消费者认知行为的SICAS新模式;在明确了消费者认知行为相关因素的基础上,依据消费者的认知模型设计了针对新产品认知行为的调查问卷,通过了解消费者采用新产品过程中的决策行为,发现了消费者的认知变化;并从企业推广新产品的角度提出了一些建议。

  5. Cognitive Support using BDI Agent and Adaptive User Modeling

    DEFF Research Database (Denmark)

    Hossain, Shabbir

    2012-01-01

    -known framework to measure the individual health status and functioning level. The third goal is to develop an approach for supporting for users with irrational behaviour due to cognitive impairment. To deal with this challenge, a Belief, Desire and Intention (BDI) agent based approach is proposed due to its...... conducted using the developed system shows potentials in terms of providing freedom of mobility for the user with cognitive impairment.......The need of constant support and care for the elderly people with special needs is gradually increasing. It is becoming the primary challenge for most of the western countries and research society to innovate new eective approaches and develop novel technologies to address the demographics...

  6. Modeling cognition and disease using human glial chimeric mice

    DEFF Research Database (Denmark)

    Goldman, Steven A.; Nedergaard, Maiken; Windrem, Martha S.

    2015-01-01

    that transplanted hGPCs not only engraft and expand within murine hosts, but dynamically outcompete the resident progenitors so as to ultimately dominate the host brain. The engrafted human progenitor cells proceed to generate parenchymal astrocytes, and when faced with a hypomyelinated environment......, oligodendrocytes as well. As a result, the recipient brains may become inexorably humanized with regards to their resident glial populations, yielding human glial chimeric mouse brains. These brains provide us a fundamentally new tool by which to assess the species-specific attributes of glia in modulating human...... cognition and information processing. In addition, the cellular humanization of these brains permits their use in studying glial infectious and inflammatory disorders unique to humans, and the effects of those disorders on the glial contributions to cognition. Perhaps most intriguingly, by pairing our...

  7. Cognitive MAC Protocols for General Primary Network Models

    CERN Document Server

    Mehanna, Omar; Gamal, Hesham El

    2009-01-01

    We consider the design of cognitive Medium Access Control (MAC) protocols enabling a secondary (unlicensed) transmitter-receiver pair to communicate over the idle periods of a set of primary (licensed) channels. More specifically, we propose cognitive MAC protocols optimized for both slotted and un-slotted primary networks. For the slotted structure, the objective is to maximize the secondary throughput while maintaining synchronization between the secondary pair and not causing interference to the primary network. Our investigations differentiate between two sensing scenarios. In the first, the secondary transmitter is capable of sensing all the primary channels, whereas it senses only a subset of the primary channels in the second scenario. In both cases, we propose blind MAC protocols that efficiently learn the statistics of the primary traffic on-line and asymptotically achieve the throughput obtained when prior knowledge of primary traffic statistics is available. For the un-slotted structure, the object...

  8. Epistemology, Situated Cognition, and Mental Models: "Like a Bridge over Troubled Water."

    Science.gov (United States)

    Seel, Norbert M.

    2001-01-01

    Discusses situated cognition as a movement from epistemology, considers the construction of mental models, and describes a study of twelfth graders that investigated the significance of a conceptual model provided at the beginning of the learning process. Results show that mental models are constructed in dependence on the learning situation.…

  9. Application of Three Cognitive Diagnosis Models to ESL Reading and Listening Assessments

    Science.gov (United States)

    Lee, Yong-Won; Sawaki, Yasuyo

    2009-01-01

    The present study investigated the functioning of three psychometric models for cognitive diagnosis--the general diagnostic model, the fusion model, and latent class analysis--when applied to large-scale English as a second language listening and reading comprehension assessments. Data used in this study were scored item responses and incidence…

  10. MSEE: Stochastic Cognitive Linguistic Behavior Models for Semantic Sensing

    Science.gov (United States)

    2013-09-01

    study of human language in terms of neonatal development and evolution in human physiology, sociology, and psychology [1][2]. It offers a different...simple, and universally understood. They are the fundamental gestalts for reasoning. In semantic sensing domain, things would be the most common objects...related places. The cognitive linguistics notion of path organizes places into the structure of an event. A path is a precognitive gestalt that

  11. Cognitive Modeling of Performance Response Capacity Under Time Pressure

    Science.gov (United States)

    2010-12-31

    Dismal extends the GNU Emacs editor using its extension language, Emacs Lisp . This task environment provides the nature of cognition-demanding...process is spawned, and the model’s architecture is loaded within that process. A shell is started in Emacs to invoke OpenMCL that is a Lisp ...to type a letter or to execute a keystroke command, this can be done directly using the extension language of Emacs Lisp . If the command moves the

  12. Simulation of current generation in a 3-D plasma model

    Energy Technology Data Exchange (ETDEWEB)

    Tsung, F.S.; Dawson, J.M. [Univ. of California, Los Angeles, CA (United States)

    1996-12-31

    Two wires carrying current in the same direction will attract each other, and two wires carrying current in the opposite direction will repel each other. Now, consider a test charge in a plasma. If the test charge carries current parallel to the plasma, then it will be pulled toward the plasma core, and if the test charge carries current anti-parallel to the plasma, then it will be pushed to the edge. The electromagnetic coupling between the plasma and a test charge (i.e., the A{sub {parallel}} {circ} v{sub {parallel}} term in the test charge`s Hamiltonian) breaks the symmetry in the parallel direction, and gives rise to a diffusion coefficient which is dependent on the particle`s parallel velocity. This is the basis for the {open_quotes}preferential loss{close_quotes} mechanism described in the work by Nunan et al. In our previous 2+{1/2}D work, in both cylindrical and toroidal geometries, showed that if the plasma column is centrally fueled, then an initial current increases steadily. The results in straight, cylindrical plasmas showed that self generated parallel current arises without trapped particle or neoclassical diffusion, as assumed by the bootstrap theory. It suggests that the fundamental mechanism seems to be the conservation of particles canonical momenta in the direction of the ignorable coordinate. We have extended the simulation to 3D to verify the model put forth. A scalable 3D EM-PIC code, with a localized field-solver, has been implemented to run on a large class of parallel computers. On the 512-node SP2 at Cornell Theory Center, we have benchmarked the 2+{1/2}D calculations using 32 grids in the previously ignored direction, and a 100-fold increase in the number of particles. Our preliminary results show good agreements between the 2+{1/2}D and the 3D calculations. We will present our 3D results at the meeting.

  13. A cognitive model of second-year organic chemistry students' conceptualizations of mental molecular rotation

    Science.gov (United States)

    Briggs, Michael W.

    The goal of this research was to answer the question, "What is a plausible explanation (model) of the cognitive structure and processes that facilitate mental molecular rotation?". This work used phenomenographic methodology and techniques of interview and think-aloud protocol. Constructivism was the theoretical framework. At the outset of the research, I designed nine tasks to obtain participant articulations of conceptualizations of mental molecular rotations. Articulations from five second-year organic chemistry students attending a Midwestern research university became the research data. Analysis produced four emerging themes along two axes: visualization representation and modeling cognition. These two axes formed a mental space, which was modeled by structure and processes that facilitated mental molecular rotation. A theoretical cognitive model of mental molecular rotation was based on the work of two researchers: Robbie Case and Richard Lesh. Lesh's "mental model" is composed of cognitive elements and operations, which are distributed over heeded local and global cognitive sub-models whereas Case deals with unheeded central conceptual structures. The models and structures interact to produce new knowledge and facilitate the use of existing knowledge. Two predictions of the theory of mental molecular rotation were elaborated. Students without a set of operations in a central conceptual structure will not be able to mentally rotate molecules. This is true even if a set of components, other than "operation", is constructed. The artifacts of mental molecular rotation can be used to determine the state of construction of the central conceptual structure responsible for mental molecular rotation.

  14. Modeling of leakage currents in high-k dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Jegert, Gunther Christian

    2012-03-15

    Leakage currents are one of the major bottlenecks impeding the downscaling efforts of the semiconductor industry. Two core devices of integrated circuits, the transistor and, especially, the DRAM storage capacitor, suffer from the increasing loss currents. In this perspective a fundamental understanding of the physical origin of these leakage currents is highly desirable. However, the complexity of the involved transport phenomena so far has prevented the development of microscopic models. Instead, the analysis of transport through the ultra-thin layers of high-permittivity (high-k) dielectrics, which are employed as insulating layers, was carried out at an empirical level using simple compact models. Unfortunately, these offer only limited insight into the physics involved on the microscale. In this context the present work was initialized in order to establish a framework of microscopic physical models that allow a fundamental description of the transport processes relevant in high-k thin films. A simulation tool that makes use of kinetic Monte Carlo techniques was developed for this purpose embedding the above models in an environment that allows qualitative and quantitative analyses of the electronic transport in such films. Existing continuum approaches, which tend to conceal the important physics behind phenomenological fitting parameters, were replaced by three-dimensional transport simulations at the level of single charge carriers. Spatially localized phenomena, such as percolation of charge carriers across pointlike defects, being subject to structural relaxation processes, or electrode roughness effects, could be investigated in this simulation scheme. Stepwise a self-consistent, closed transport model for the TiN/ZrO{sub 2} material system, which is of outmost importance for the semiconductor industry, was developed. Based on this model viable strategies for the optimization of TiN/ZrO{sub 2}/TiN capacitor structures were suggested and problem areas

  15. Toward affect-inclusive models of cognitive dynamics: Coupling epistemological resources and emotions

    CERN Document Server

    Gupta, Ayush; Elby, Andrew

    2013-01-01

    Many prominent lines of research on student's reasoning and conceptual change within learning sciences and physics education research have not attended to the role of learners' affect or emotions in the dynamics of their conceptual reasoning. This is despite evidence from psychology and cognitive- and neuro- sciences that emotions are deeply integrated with cognition and documented associations in education research between emotions and academic performance. The few studies that have aimed to integrate emotions within models of learners' cognition, have mostly done so at a coarse grain size. In this manuscript, toward the long-term goal of incorporating emotions into fine-grained models of in-themoment cognitive dynamics, we present a case study of Judy, an undergraduate electrical engineering and physics major. We argue that a fine-grained aspect of Judy's affect, her annoyance at a particular kind of homework problem, stabilizes a context-dependent epistemological stance she displays, about an unbridgeable ...

  16. A cognitive-behavioral model of Internet gaming disorder: theoretical underpinnings and clinical implications.

    Science.gov (United States)

    Dong, Guangheng; Potenza, Marc N

    2014-11-01

    Cognitive contributions to the behaviors observed in substance and non-substance addictions have been investigated and characterized. Based on models of drug addictions and the extant literature on Internet gaming disorder (IGD), we propose a cognitive-behavioral model for conceptualizing IGD. The model focuses on three domains and their roles in addictive behaviors. The three domains include motivational drives related to reward-seeking and stress-reduction, behavioral control relating to executive inhibition, and decision-making that involves weighing the pros and cons of engaging in motivated behaviors. Based on this model, we propose how behavioral therapies might target these domains in the treatment of IGD.

  17. Semiparametric Additive Transformation Model under Current Status Data

    CERN Document Server

    Cheng, Guang

    2011-01-01

    We consider the efficient estimation of the semiparametric additive transformation model with current status data. A wide range of survival models and econometric models can be incorporated into this general transformation framework. We apply the B-spline approach to simultaneously estimate the linear regression vector, the nondecreasing transformation function, and a set of nonparametric regression functions. We show that the parametric estimate is semiparametric efficient in the presence of multiple nonparametric nuisance functions. An explicit consistent B-spline estimate of the asymptotic variance is also provided. All nonparametric estimates are smooth, and shown to be uniformly consistent and have faster than cubic rate of convergence. Interestingly, we observe the convergence rate interfere phenomenon, i.e., the convergence rates of B-spline estimators are all slowed down to equal the slowest one. The constrained optimization is not required in our implementation. Numerical results are used to illustra...

  18. Biologically Inspired Visual Model With Preliminary Cognition and Active Attention Adjustment.

    Science.gov (United States)

    Qiao, Hong; Xi, Xuanyang; Li, Yinlin; Wu, Wei; Li, Fengfu

    2015-11-01

    Recently, many computational models have been proposed to simulate visual cognition process. For example, the hierarchical Max-Pooling (HMAX) model was proposed according to the hierarchical and bottom-up structure of V1 to V4 in the ventral pathway of primate visual cortex, which could achieve position- and scale-tolerant recognition. In our previous work, we have introduced memory and association into the HMAX model to simulate visual cognition process. In this paper, we improve our theoretical framework by mimicking a more elaborate structure and function of the primate visual cortex. We will mainly focus on the new formation of memory and association in visual processing under different circumstances as well as preliminary cognition and active adjustment in the inferior temporal cortex, which are absent in the HMAX model. The main contributions of this paper are: 1) in the memory and association part, we apply deep convolutional neural networks to extract various episodic features of the objects since people use different features for object recognition. Moreover, to achieve a fast and robust recognition in the retrieval and association process, different types of features are stored in separated clusters and the feature binding of the same object is stimulated in a loop discharge manner and 2) in the preliminary cognition and active adjustment part, we introduce preliminary cognition to classify different types of objects since distinct neural circuits in a human brain are used for identification of various types of objects. Furthermore, active cognition adjustment of occlusion and orientation is implemented to the model to mimic the top-down effect in human cognition process. Finally, our model is evaluated on two face databases CAS-PEAL-R1 and AR. The results demonstrate that our model exhibits its efficiency on visual recognition process with much lower memory storage requirement and a better performance compared with the traditional purely computational

  19. Network-oriented modeling addressing complexity of cognitive, affective and social interactions

    CERN Document Server

    Treur, Jan

    2016-01-01

    This book presents a new approach that can be applied to complex, integrated individual and social human processes. It provides an alternative means of addressing complexity, better suited for its purpose than and effectively complementing traditional strategies involving isolation and separation assumptions. Network-oriented modeling allows high-level cognitive, affective and social models in the form of (cyclic) graphs to be constructed, which can be automatically transformed into executable simulation models. The modeling format used makes it easy to take into account theories and findings about complex cognitive and social processes, which often involve dynamics based on interrelating cycles. Accordingly, it makes it possible to address complex phenomena such as the integration of emotions within cognitive processes of all kinds, of internal simulations of the mental processes of others, and of social phenomena such as shared understandings and collective actions. A variety of sample models – including ...

  20. Modeling of finite aspect ratio effects on current drive

    Energy Technology Data Exchange (ETDEWEB)

    Wright, J.C.; Phillips, C.K. [Princeton Plasma Physics Lab., NJ (United States)

    1996-12-31

    Most 2D RF modeling codes use a parameterization of current drive efficiencies to calculate fast wave driven currents. This parameterization assumes a uniform diffusion coefficient and requires a priori knowledge of the wave polarizations. These difficulties may be avoided by a direct calculation of the quasilinear diffusion coefficient from the Kennel-Englemann form with the field polarizations calculated by a full wave code. This eliminates the need to use the approximation inherent in the parameterization. Current profiles are then calculated using the adjoint formulation. This approach has been implemented in the FISIC code. The accuracy of the parameterization of the current drive efficiency, {eta}, is judged by a comparison with a direct calculation: where {chi} is the adjoint function, {epsilon} is the kinetic energy, and {rvec {Gamma}} is the quasilinear flux. It is shown that for large aspect ratio devices ({epsilon} {r_arrow} 0), the parameterization is nearly identical to the direct calculation. As the aspect ratio approaches unity, visible differences between the two calculations appear.

  1. Understanding and predicting online purchase intention: Development of a model for cognitive-affective shopper responses

    OpenAIRE

    Lu, KJ

    2016-01-01

    This paper aims to develop a model for online purchase intention in a B2C environment, integrating cognitive and affective responses based on the theory of reasoned action. Seven hypotheses were developedand tested on a dataset of 532 observations collected via a questionnaire survey. The results of this study indicate that both cognitive and affective judgements are important for online transactions.A contribution of this study is that it extends our understanding of how online purchase inte...

  2. Developing a Creative-Cognitive Model of Entrepreneurial Alertness to Business Opportunities

    OpenAIRE

    Vesa Puhakka

    2011-01-01

    A creative-cognitive perspective is used in this study to explore alertness to business opportunities in order to develop a model of business opportunity recognition. It is assumed that the elements constituting this opportunity creation are entrepreneur¡¯s creative cognitive process, internal creative qualities, environmental conditions supporting or hindering creativity and interaction of these elements, and that they have a significant impact on the innovativeness of the business opportuni...

  3. Considering structural connectivity in the triple code model of numerical cognition: differential connectivity for magnitude processing and arithmetic facts.

    Science.gov (United States)

    Klein, Elise; Suchan, Julia; Moeller, Korbinian; Karnath, Hans-Otto; Knops, André; Wood, Guilherme; Nuerk, Hans-Christoph; Willmes, Klaus

    2016-03-01

    The current study provides a generalizable account of the anatomo-functional associations as well as the connectivity of representational codes underlying numerical processing as suggested by the triple code model (TCM) of numerical cognition. By evaluating the neural networks subserving numerical cognition in two specific and substantially different numerical tasks with regard to both grey matter localizations as well as white matter tracts we (1) considered the possibility of additional memory-related cortex areas crucial for arithmetic fact retrieval (e.g., the hippocampus); (2) specified the functional involvement of prefrontal areas in number magnitude processing, and, finally; (3) identified the connections between these anatomo-functional instantiations of the representations involved in number magnitude processing and arithmetic fact retrieval employing probabilistic fiber tracking. The resulting amendments to the TCM are summarized in a schematic update, and ideas concerning the possible functional interplay between number magnitude processing and arithmetic fact retrieval are discussed.

  4. Advances in modeling of lower hybrid current drive

    Science.gov (United States)

    Peysson, Y.; Decker, J.; Nilsson, E.; Artaud, J.-F.; Ekedahl, A.; Goniche, M.; Hillairet, J.; Ding, B.; Li, M.; Bonoli, P. T.; Shiraiwa, S.; Madi, M.

    2016-04-01

    First principle modeling of the lower hybrid (LH) current drive in tokamak plasmas is a longstanding activity, which is gradually gaining in accuracy thanks to quantitative comparisons with experimental observations. The ability to reproduce simulatenously the plasma current and the non-thermal bremsstrahlung radial profiles in the hard x-ray (HXR) photon energy range represents in this context a significant achievement. Though subject to limitations, ray tracing calculations are commonly used for describing wave propagation in conjunction with Fokker-Planck codes, as it can capture prominent features of the LH wave dynamics in a tokamak plasma-like toroidal refraction. This tool has been validated on several machines when the full absorption of the LH wave requires the transfer of a small fraction of power from the main lobes of the launched power spectrum to a tail at a higher parallel refractive index. Conversely, standard modeling based on toroidal refraction only becomes more challenging when the spectral gap is large, except if other physical mechanisms may dominate to bridge it, like parametric instabilities, as suggested for JET LH discharges (Cesario et al 2004 Phys. Rev. Lett. 92 175002), or fast fluctuations of the launched power spectrum or ‘tail’ LH model, as shown for Tore Supra (Decker et al 2014 Phys. Plasma 21 092504). The applicability of the heuristic ‘tail’ LH model is investigated for a broader range of plasma parameters as compared to the Tore Supra study and with different LH wave characteristics. Discrepancies and agreements between simulations and experiments depending upon the different models used are discussed. The existence of a ‘tail’ in the launched power spectrum significantly improves the agreement between modeling and experiments in plasma conditions for which the spectral gap is large in EAST and Alcator C-Mod tokamaks. For the Alcator C-Mod tokamak, the experimental evolution of the HXR profiles with density suggests

  5. Alcoholics Anonymous and twelve-step recovery: a model based on social and cognitive neuroscience.

    Science.gov (United States)

    Galanter, Marc

    2014-01-01

    In the course of achieving abstinence from alcohol, longstanding members of Alcoholics Anonymous (AA) typically experience a change in their addiction-related attitudes and behaviors. These changes are reflective of physiologically grounded mechanisms which can be investigated within the disciplines of social and cognitive neuroscience. This article is designed to examine recent findings associated with these disciplines that may shed light on the mechanisms underlying this change. Literature review and hypothesis development. Pertinent aspects of the neural impact of drugs of abuse are summarized. After this, research regarding specific brain sites, elucidated primarily by imaging techniques, is reviewed relative to the following: Mirroring and mentalizing are described in relation to experimentally modeled studies on empathy and mutuality, which may parallel the experiences of social interaction and influence on AA members. Integration and retrieval of memories acquired in a setting like AA are described, and are related to studies on storytelling, models of self-schema development, and value formation. A model for ascription to a Higher Power is presented. The phenomena associated with AA reflect greater complexity than the empirical studies on which this article is based, and certainly require further elucidation. Despite this substantial limitation in currently available findings, there is heuristic value in considering the relationship between the brain-based and clinical phenomena described here. There are opportunities for the study of neuroscientific correlates of Twelve-Step-based recovery, and these can potentially enhance our understanding of related clinical phenomena. © American Academy of Addiction Psychiatry.

  6. The efficacy of mindfulness-based cognitive therapy in recurrent depressed patients with and without a current depressive episode: a randomized controlled trial.

    NARCIS (Netherlands)

    Aalderen, J.R. van; Donders, A.R.T.; Giommi, F.; Spinhoven, P.; Barendregt, H.P.; Speckens, A.E.M.

    2012-01-01

    BACKGROUND: The aim of this study is to examine the efficacy of mindfulness-based cognitive therapy (MBCT) in addition to treatment as usual (TAU) for recurrent depressive patients with and without a current depressive episode. METHOD: A randomized, controlled trial comparing MBCT+TAU (n=102) with T

  7. Massive fermion model in 3d and higher spin currents

    CERN Document Server

    Bonora, L; Prester, P Dominis; de Souza, B Lima; Smolic, I

    2016-01-01

    We analyze the 3d free massive fermion theory coupled to external sources. The presence of a mass explicitly breaks parity invariance. We calculate two- and three-point functions of a gauge current and the energy momentum tensor and, for instance, obtain the well-known result that in the IR limit (but also in the UV one) we reconstruct the relevant CS action. We then couple the model to higher spin currents and explicitly work out the spin 3 case. In the UV limit we obtain an effective action which was proposed many years ago as a possible generalization of spin 3 CS action. In the IR limit we derive a different higher spin action. This analysis can evidently be generalized to higher spins. We also discuss the conservation and properties of the correlators we obtain in the intermediate steps of our derivation.

  8. Assessments of cognitive abilities in a mouse model of Parkinson's disease with a touch screen test.

    Science.gov (United States)

    Kwak, Chuljung; Lim, Chae-Seok; Kaang, Bong-Kiun

    2016-03-15

    Patients with Parkinson's disease (PD) experience both motor output deficits and cognitive disabilities. Various PD rodent models have been developed to investigate the genetic and brain circuit-related causes of PD and have contributed to the basic and clinical research and to therapeutic strategies for this disease. Most studies using PD rodent models have focused on the motor output deficits, rather than cognitive disabilities due to the lack of appropriate testing tools that do not require significant motor abilities. In this study, we assessed the cognitive disabilities of PD model mice using a touch screen test that required only little motor ability. We found that the PD model mice, which had motor deficits caused by unilateral striatal dopaminergic degeneration, successfully underwent operant conditioning with a touch screen test. Additionally, we found that the PD model mice demonstrated impaired location discrimination, but intact attention and reversal learning in the cognitive tests. Therefore, the touch screen test is useful for assessing hidden cognitive disabilities in disease model animals with decreased motor function.

  9. l-Carnitine improves cognitive and renal functions in a rat model of chronic kidney disease.

    Science.gov (United States)

    Abu Ahmad, Nur; Armaly, Zaher; Berman, Sylvia; Jabour, Adel; Aga-Mizrachi, Shlomit; Mosenego-Ornan, Efrat; Avital, Avi

    2016-10-01

    Over the past decade, the prevalence of chronic kidney disease (CKD) has reached epidemic proportions. The search for novel pharmacological treatment for CKD has become an area of intensive clinical research. l-Carnitine, considered as the "gatekeeper" responsible for admitting long chain fatty acids into cell mitochondria. l-Carnitine synthesis and turnover are regulated mainly by the kidney and its levels inversely correlate with serum creatinine of normal subjects and CKD patients. Previous studies showed that l-carnitine administration to elderly people is improving and preserving cognitive function. As yet, there are no clinical intervention studies that investigated the effect of l-carnitine administration on cognitive impairment evidenced in CKD patients. Thus, we aimed to investigate the effects of l-carnitine treatment on renal function and on the cognitive performance in a rat model of progressive CKD. To assess the role of l-carnitine on CKD condition, we estimated the renal function and cognitive abilities in a CKD rat model. We found that all CKD animals exhibited renal function deterioration, as indicated by elevated serum creatinine, BUN, and ample histopathological abnormalities. l-Carnitine treatment of CKD rats significantly reduced serum creatinine and BUN, attenuated renal hypertrophy and decreased renal tissue damage. In addition, in the two way shuttle avoidance learning, CKD animals showed cognitive impairment which recovered by the administration of l-carnitine. We conclude that in a rat model of CKD, l-carnitine administration significantly improved cognitive and renal functions.

  10. Modeling of current distribution on smooth and columnar platinum structures.

    Science.gov (United States)

    Zinola, Carlos F

    2011-01-17

    Studying the growth and stability of anisotropic or isotropic disordered surfaces in electrodeposition is of importance in catalytic electrochemistry. In some cases, the metallic nature of the electrode defines the topography and roughness, which are also controlled by the experimental time and applied external potential. Because of the experimental restrictions in conventional electrochemical techniques and ex situ electron microscopies, a theoretical model of the surface geometry could aid in understanding the electrodeposition process and current distributions. In spite of applying a complex theory such as dynamic scaling method or perturbation theories, the resolution of mixed mass-/charge-transfer equations (tertiary distribution) for the electrodeposition process would give reliable information. One of the main problems with this type of distribution is the mathematics when solving the spatial n-dimensional differential equations. Use of a primary current distribution is proposed here to simplify the differential equations; however it limits wide application of the first assumption. Distributions of concentration profile, current density, and electrode potential are presented here as a function of the distance normal to the surface for the cases of smooth and rough platinum growth. In the particular case of columnar surfaces, cycloid curves are used to model the electrode, from which the concentration profile is presented in a parameterized form after solving a first-type curvilinear integral. The concentration contour results in a combination of a trigonometric inverse function and a linear distribution leading to a negative concavity curve. The calculation of the current density and electrode potential contours also show trigonometric shapes exhibiting forbidden imaginary values only at the minimal values of the trochoid curve.

  11. Comparison of Return Stroke Current Profiles for Transmission-Line-Type and Traveling-Current-Source-Type Models

    Directory of Open Access Journals (Sweden)

    J.O. Adepitan

    2012-05-01

    Full Text Available The study is aimed at determining the dependence of the current along a channel on the model used, assuming the same base current. We compared three transmission-line-type models, namely: Transmission Line (TL, Modified Transmission Line with Linear decay, Modified Transmission Line with Exponential decay and two traveling-current-source-type models: Bruce-Golde (BG and Traveling Current Source (TCS models. The current profiles along the channel at different heights predicted by these models are presented and discussed. Comparison is based on the assumption that all the models have the same base current. It was found that at low heights and within a time window frame of 15 :s, the currents of the transmission-line-type models predict a zero value at one time or the other with a maximum turning point following some 1:s after. A linear relationship is predicted between the current peak and the channel height. A discontinuity of current peak was observed at high heights. No zero value of current was recorded in case of TCS both at low and high channel heights.

  12. Animal models of transcranial direct current stimulation: Methods and mechanisms.

    Science.gov (United States)

    Jackson, Mark P; Rahman, Asif; Lafon, Belen; Kronberg, Gregory; Ling, Doris; Parra, Lucas C; Bikson, Marom

    2016-11-01

    The objective of this review is to summarize the contribution of animal research using direct current stimulation (DCS) to our understanding of the physiological effects of transcranial direct current stimulation (tDCS). We comprehensively address experimental methodology in animal studies, broadly classified as: (1) transcranial stimulation; (2) direct cortical stimulation in vivo and (3) in vitro models. In each case advantages and disadvantages for translational research are discussed including dose translation and the overarching "quasi-uniform" assumption, which underpins translational relevance in all animal models of tDCS. Terminology such as anode, cathode, inward current, outward current, current density, electric field, and uniform are defined. Though we put key animal experiments spanning decades in perspective, our goal is not simply an exhaustive cataloging of relevant animal studies, but rather to put them in context of ongoing efforts to improve tDCS. Cellular targets, including excitatory neuronal somas, dendrites, axons, interneurons, glial cells, and endothelial cells are considered. We emphasize neurons are always depolarized and hyperpolarized such that effects of DCS on neuronal excitability can only be evaluated within subcellular regions of the neuron. Findings from animal studies on the effects of DCS on plasticity (LTP/LTD) and network oscillations are reviewed extensively. Any endogenous phenomena dependent on membrane potential changes are, in theory, susceptible to modulation by DCS. The relevance of morphological changes (galvanotropy) to tDCS is also considered, as we suggest microscopic migration of axon terminals or dendritic spines may be relevant during tDCS. A majority of clinical studies using tDCS employ a simplistic dose strategy where excitability is singularly increased or decreased under the anode and cathode, respectively. We discuss how this strategy, itself based on classic animal studies, cannot account for the

  13. Thinking outside the boxes: Using current reading models to assess and treat developmental surface dyslexia.

    Science.gov (United States)

    Law, Caroline; Cupples, Linda

    2017-03-01

    Improving the reading performance of children with developmental surface dyslexia has proved challenging, with limited generalisation of reading skills typically reported after intervention. The aim of this study was to provide tailored, theoretically motivated intervention to two children with developmental surface dyslexia. Our objectives were to improve their reading performance, and to evaluate the utility of current reading models in therapeutic practice. Detailed reading and cognitive profiles for two male children with developmental surface dyslexia were compared to the results obtained by age-matched control groups. The specific area of single-word reading difficulty for each child was identified within the dual route model (DRM) of reading, following which a theoretically motivated intervention programme was devised. Both children showed significant improvements in single-word reading ability after training, with generalisation effects observed for untrained words. However, the assessment and intervention results also differed for each child, reinforcing the view that the causes and consequences of developmental dyslexia, even within subtypes, are not homogeneous. Overall, the results of the interventions corresponded more closely with the DRM than other current reading models, in that real word reading improved in the absence of enhanced nonword reading for both children.

  14. Operational advances in ring current modeling using RAM-SCB

    Energy Technology Data Exchange (ETDEWEB)

    Welling, Daniel T [Los Alamos National Laboratory; Jordanova, Vania K [Los Alamos National Laboratory; Zaharia, Sorin G [Los Alamos National Laboratory; Morley, Steven K [Los Alamos National Laboratory

    2010-12-03

    The Ring current Atmosphere interaction Model with Self-Consistently calculated 3D Magnetic field (RAM-SCB) combines a kinetic model of the ring current with a force-balanced model of the magnetospheric magnetic field to create an inner magnetospheric model that is magnetically self consistent. RAM-SCB produces a wealth of outputs that are valuable to space weather applications. For example, the anisotropic particle distribution of the KeV-energy population calculated by the code is key for predicting surface charging on spacecraft. Furthermore, radiation belt codes stand to benefit substantially from RAM-SCB calculated magnetic field values and plasma wave growth rates - both important for determining the evolution of relativistic electron populations. RAM-SCB is undergoing development to bring these benefits to the space weather community. Data-model validation efforts are underway to assess the performance of the system. 'Virtual Satellite' capability has been added to yield satellite-specific particle distribution and magnetic field output. The code's outer boundary is being expanded to 10 Earth Radii to encompass previously neglected geosynchronous orbits and allow the code to be driven completely by either empirical or first-principles based inputs. These advances are culminating towards a new, real-time version of the code, rtRAM-SCB, that can monitor the inner magnetosphere conditions on both a global and spacecraft-specific level. This paper summarizes these new features as well as the benefits they provide the space weather community.

  15. Dogs with cognitive dysfunction as a spontaneous model for early Alzheimer's Disease

    DEFF Research Database (Denmark)

    Schütt, Trine; Helboe, Lone; Pedersen, Lars Østergaard

    2016-01-01

    Aged companion dogs with canine cognitive dysfunction (CCD) spontaneously develop varying degrees of progressive cognitive decline and particular neuropathological features correspondent to the changes associated with Alzheimer's disease (AD) in humans. The aim of the present study was to charact......Aged companion dogs with canine cognitive dysfunction (CCD) spontaneously develop varying degrees of progressive cognitive decline and particular neuropathological features correspondent to the changes associated with Alzheimer's disease (AD) in humans. The aim of the present study...... was to characterize certain aspects of neuropathology and inflammatory markers related to aging and CCD in dogs in comparison with human AD. Fifteen brains from aged dogs with normal cognitive function, mild cognitive impairment, or CCD were investigated and compared with two control brains from young dogs and brain...... support the senescent dog with spontaneous cognitive dysfunction as a valuable non-transgenic model for further investigations of the molecular events involved in the neurodegenerative processes associated with aging and early stage AD, especially the Aβ-related pathology....

  16. Anatomy and computational modeling of networks underlying cognitive-emotional interaction

    Directory of Open Access Journals (Sweden)

    Yohan Joshua John

    2013-04-01

    Full Text Available The classical dichotomy between cognition and emotion equated the first with rationality or logic and the second with irrational behaviors. The idea that cognition and emotion are separable, antagonistic forces competing for dominance of mind has been hard to displace despite abundant evidence to the contrary. For instance, it is now known that a pathological absence of emotion leads to profound impairment of decision making. Behavioral observations of this kind are corroborated at the mechanistic level: neuroanatomical studies reveal that brain areas typically described as underlying either cognitive or emotional processes are linked in ways that imply complex interactions that do not resemble a simple mutual antagonism. Instead, physiological studies and network simulations suggest that top-down signals from prefrontal cortex realize ``cognitive control'' in part by either suppressing or promoting emotional responses controlled by the amygdala, in a way that facilitates adaptation to changing task demands. Behavioral, anatomical, and physiological data suggest that emotion and cognition are equal partners in enabling a continuum or matrix of flexible behaviors that are subserved by multiple brain regions acting in concert. Here we focus on neuroanatomical data that highlight circuitry that structures cognitive-emotional interactions by directly or indirectly linking prefrontal areas with the amygdala. We also present an initial computational circuit model, based on anatomical, physiological and behavioral data to explicitly frame the learning and performance mechanisms by which cognition and emotion interact to achieve flexible behavior.

  17. Anatomy and computational modeling of networks underlying cognitive-emotional interaction.

    Science.gov (United States)

    John, Yohan J; Bullock, Daniel; Zikopoulos, Basilis; Barbas, Helen

    2013-01-01

    The classical dichotomy between cognition and emotion equated the first with rationality or logic and the second with irrational behaviors. The idea that cognition and emotion are separable, antagonistic forces competing for dominance of mind has been hard to displace despite abundant evidence to the contrary. For instance, it is now known that a pathological absence of emotion leads to profound impairment of decision making. Behavioral observations of this kind are corroborated at the mechanistic level: neuroanatomical studies reveal that brain areas typically described as underlying either cognitive or emotional processes are linked in ways that imply complex interactions that do not resemble a simple mutual antagonism. Instead, physiological studies and network simulations suggest that top-down signals from prefrontal cortex realize "cognitive control" in part by either suppressing or promoting emotional responses controlled by the amygdala, in a way that facilitates adaptation to changing task demands. Behavioral, anatomical, and physiological data suggest that emotion and cognition are equal partners in enabling a continuum or matrix of flexible behaviors that are subserved by multiple brain regions acting in concert. Here we focus on neuroanatomical data that highlight circuitry that structures cognitive-emotional interactions by directly or indirectly linking prefrontal areas with the amygdala. We also present an initial computational circuit model, based on anatomical, physiological, and behavioral data to explicitly frame the learning and performance mechanisms by which cognition and emotion interact to achieve flexible behavior.

  18. Testing the hypothesis on cognitive evolution of modern humans' learning ability: current status of past-climatic approaches.

    Science.gov (United States)

    Yoneda, Minoru; Abe-Ouchi, Ayako; Kawahata, Hodaka; Yokoyama, Yusuke; Oguchi, Takashi

    2014-05-01

    The impact of climate change on human evolution is important and debating topic for many years. Since 2010, we have involved in a general joint project entitled "Replacement of Neanderthal by Modern Humans: Testing Evolutional Models of Learning", which based on a theoretical prediction that the cognitive ability related to individual and social learning divide fates of ancient humans in very unstable Late Pleistocene climate. This model predicts that the human populations which experienced a series of environmental changes would have higher rate of individual learners, while detailed reconstructions of global climate change have reported fluent and drastic change based on ice cores and stalagmites. However, we want to understand the difference between anatomically modern human which survived and the other archaic extinct humans including European Neanderthals and Asian Denisovans. For this purpose the global synchronized change is not useful for understanding but the regional difference in the amplitude and impact of climate change is the information required. Hence, we invited a geophysicist busing Global Circulation Model to reconstruct the climatic distribution and temporal change in a continental scale. At the same time, some geochemists and geographers construct a database of local climate changes recorded in different proxies. At last, archaeologists and anthropologists tried to interpret the emergence and disappearance of human species in Europe and Asia on the reconstructed past climate maps using some tools, such as Eco-cultural niche model. Our project will show the regional difference in climate change and related archaeological events and its impact on the evolution of learning ability of modern humans.

  19. Current state of genome-scale modeling in filamentous fungi.

    Science.gov (United States)

    Brandl, Julian; Andersen, Mikael R

    2015-06-01

    The group of filamentous fungi contains important species used in industrial biotechnology for acid, antibiotics and enzyme production. Their unique lifestyle turns these organisms into a valuable genetic reservoir of new natural products and biomass degrading enzymes that has not been used to full capacity. One of the major bottlenecks in the development of new strains into viable industrial hosts is the alteration of the metabolism towards optimal production. Genome-scale models promise a reduction in the time needed for metabolic engineering by predicting the most potent targets in silico before testing them in vivo. The increasing availability of high quality models and molecular biological tools for manipulating filamentous fungi renders the model-guided engineering of these fungal factories possible with comprehensive metabolic networks. A typical fungal model contains on average 1138 unique metabolic reactions and 1050 ORFs, making them a vast knowledge-base of fungal metabolism. In the present review we focus on the current state as well as potential future applications of genome-scale models in filamentous fungi.

  20. MENS, an Info-Computational Model for (Neuro-cognitive Systems Capable of Creativity

    Directory of Open Access Journals (Sweden)

    Andrée C. Ehresmann

    2012-09-01

    Full Text Available MENS is a bio-inspired model for higher level cognitive systems; it is an application of the Memory Evolutive Systems developed with Vanbremeersch to model complex multi-scale, multi-agent self-organized systems, such as biological or social systems. Its development resorts to an info-computationalism: first we characterize the properties of the human brain/mind at the origin of higher order cognitive processes up to consciousness and creativity, then we ‘abstract’ them in a MENS mathematical model for natural or artificial cognitive systems. The model, based on a ‘dynamic’ Category Theory incorporating Time, emphasizes the computability problems which are raised.